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BACKGROUND OF THE INVENTION AND PRIOR ART
The present invention relates to the art of computer driven inkjet printing devices, like ink jet printers, multi-function printing/scanning devices, faxes, copiers or the like. Devices of this type have a printhead carriage which is mounted for reciprocal movement on the device in a direction orthogonal to the direction of movement of the paper or other medium on which printing is to take place through the device. For sake of simplicity, in the following we refer to an inkjet printer only, but the same will apply to any inkjet printing devices, mutatis mutandis. The printer carriage of a printer typically has from one to four or more ink jet printheads mounted thereon, e.g. piezoelectric or thermal printhead. Each of the printheads contains a supply of ink which, for large scale printers, is generally inadequate due to the large volumes of ink which are required as compared with the ink supply requirements of desk top printers. Consequently, various means have been proposed for continuously or periodically refilling the carriage-borne printheads with ink. These systems fall into two categories. The first comprises off-board or off-axis ink reservoirs which are continuously connected to the carriage-borne or onboard printheads by flexible tubes. The second comprises a “take a gulp” system in which the printhead carriage is periodically moved to one end of its path of travel where it is then connected with off-axis ink reservoirs to fill the onboard printheads. This “take a gulp” system is disclosed in Hewlett-Packard's Designjet 2000 printer referred to in U.S. patent application Ser. No. 08/805,861 filed Mar. 3, 1997 and published in European Patent Publication No. 0863016 on Sep. 9, 1998.
Large format printers are expensive pieces of equipment which preferably should be capable of using different types of ink without significant modification of the printer. The different ink types may for convenience be broadly referred to as indoor ink and outdoor ink, meaning ink intended to be used for production of drawings, posters, and other printed material which may be displayed outdoors or indoors. Outdoor ink is pigment based, i.e. containing a plurality of discrete undissolved pigment particles suspended in a fluid carrier. Dye-based ink has a lower degree of optical density and permanence but is less expensive.
Further, in color printers four separate colors of ink are usually employed comprising black and three primary or mid-primary colors such as cyan, magenta and yellow. In color ink printers provision must also be made to ensure that neither incorrect types of ink nor incorrect colors of ink can inadvertently be used in the system.
Since the ink delivery tubes connected from off-board reservoirs to onboard printheads continually flex, leakage and breakage of the ink supply tubes is experienced. A reliable ink delivery system and guides for routing the ink delivery tubes to minimize flexing and breakage is desired.
U.S. patent application Ser. No. 09/240,091 filed on Jan. 29, 1999 describes a more reliable ink delivery system wherein the ink delivery tubes, thanks to a minimized flexing and breakage, provides the system with a longer expected lifetime. However, because of the tube routing , the tubes are continuously stressed to flexure. When the carriage moves back and forth along the scan axis the ink delivery tubes are stressed and also move causing fatigue. It turns into a life or maximum number of cycles that the tubes can make. When the tubes reach the end of them life, they can break due to fatigue. In addition, even if the flexing has been minimized, some infant failures can happen before their end of life.
If any of the tubes break, there is an ink leak through it. As a result, the printer may get damaged: as it is not controlled, the ink can get over the paper axis or the scan axis or even reach the electronics burning it. It is also possible that the ink gets out of the printer, reaching the user or the floor.
A possible solution to prevent the printer from getting damaged if a ink delivery tube is broken is to have a tube carrier enclosing it and completely sealed to be used as a secondary containment. So, if ink delivery tubes break, the ink gets contained between the ink delivery tube and the tube carrier, and it cannot damage the printer. However this solution still has some disadvantages. For instance, when the tubes break, there is an initial small crack that begins to grow. When the crack is big enough, the tube can kink and get completely broken, and its sharp edges can perforate the tube carrier. So, even if the tube carrier is well sealed it can be perforated by the broken tubes causing an ink leak over the scan axis. Moreover, it is more difficult to design and implement an easy-to-assemble plug system to seal the two ends of the tube carrier.
Applicant then realized that many of the above problems may be reduced by detecting the leakage when the crack has just begun.
In any case, since an ink leakage implies a major damage for the printer, an ink leak containment and detection system which detects and contains the leakage and preferably stops the printers, before a gross leak damage occurs, is desired.
SUMMARY OF THE INVENTION
The present invention provides an inkjet printing device having a frame, a transversely moveable printhead carriage, carrying at least one inkjet printhead, mounted for reciprocating movement on said frame, ink supply reservoir means mounted on said frame and flexible ink supply tubing for delivering ink from said ink reservoir means to said at least one inkjet printhead, said device further comprising an ink leakage detection system comprising:
a collecting unit, for collecting the ink leaked from the ink supply tubing; and
a sensing circuit coupled to said collecting unit, capable of detecting the presence of ink in said collecting unit.
The presence of a sensing circuit gives more benefits than a simple double containment since it can be used to warn the user to replace the tubes as soon as they break, reducing the risk of damaging the printer.
In addition the device further comprises an ink carrier, for conveying the leaked ink into the collecting unit. The ink carrier comprises additional tubing, having apertures at a first end and at a second end, coaxially containing said flexible ink supply tubing to bound so said flexible ink supply tubing, wherein the aperture at the first end of said additional tubing is sealed.
Accordingly, a manufacture may obtain an additional advantage since it is easier to design an easy-to-assemble plug system to seal just one end of the additional tubing than to seal the two ends as in a simple double containment system, and it can detect the leak in time before the tube breaks completely, reducing the risk of perforating the tube carrier.
Moreover if the tubes break, it avoids gross damage of the printer or to spread ink around, in particular on the user. This also improves the replaceability and serviceability of the ink delivery system: if the tubes break it is simpler to change the ink delivery system. In addition, this leak detection system can also work for any length of printer, and it is particularly simple and easy to implement.
The present invention further provides an inkjet printing device having a frame, a transversely moveable printhead carriage, carrying at least one inkjet printhead, mounted for reciprocating movement on said frame, ink supply reservoir means mounted on said frame and flexible tubing means for delivering ink from said ink reservoir means to said at least one inkjet printhead, said device further comprising an ink leakage detection system comprising:
collecting means, for collecting the ink leaked from the ink supply tubing; and
sensing means coupled to said collecting means, capable of detecting the presence of ink in said collecting means.
In accordance to a different aspect of the present invention there is provided a method of detecting an ink leak in an inkjet printing device comprising the step of:
a) conveying the ink leak from an ink delivery system to an ink collector;
b) sensing when ink is present in the ink collector
c) providing the information that an ink leakage is present in the device.
In accordance to a further different aspect of the present invention there is provided a method of detecting an ink leak in an inkjet printing device comprising the step of:
a) conveying the ink leak from an ink delivery system to an ink collector;
b) sensing when ink is present in the ink collector;
c) providing the information that an ink leakage is present in the device;
d) stopping the device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a large format printer in which the present invention is useful.
FIG. 2 is a top plan view of the printer with its cover removed to show the printhead carriage and ink tube guides and supports.
FIG. 3 is a front elevation view of the upper portion of the printer with cover removed to show the printhead carriage and attached printhead connector tubes.
FIG. 4 is a vertical cross-section taken at line 4 — 4 on FIG. 2 through the relevant portions of the printer showing the relative position of the carriage, the tube guide system and the ink delivery tubes with a printhead holddown cover on the carriage in its closed position.
FIG. 5 is a vertical cross-section taken at line 5 — 5 on FIG. 2 through the relevant portions of the printer showing the relative position of the carriage, the tube guide system and the ink delivery tubes with the printhead holddown cover in its open or raised position.
FIG. 6 is a partial front elevation of the rear tube guide and a tube clip partly broken away to show internal construction, fastening the ink tubes to the rear tube guide.
FIG. 7 is a partial front elevation view of the rear tube guide with the tube clip and tubes removed.
FIG. 8 is a rear elevation view of the tube clip, FIG. 8A being an enlarged cross-section at line 8 A— 8 A of FIG. 8 .
FIG. 9 is a right side elevation of a carriage connector and an ink tube support.
FIG. 10 is a schematic vertical cross-section through the relevant portions of the printer showing the relative positions of the carriage, the ink delivery tubes and the ink leakage system.
FIG. 11 is a schematic design of an electrical circuit used in the ink leakage system to detect ink leakage in accordance with one embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a large format printer 10 of the type which includes a transversely movable printhead carriage enclosed by a plastic or metal hinged cover 12 which extends over a generally horizontally extending platen 14 over which printed media is discharged. At the left side of the platen is a transparent hinged cover 16 which contains four removable ink reservoirs 20 , 22 , 24 , 26 which, through a flexible tube arrangement, supply ink to four inkjet printheads mounted on the moveable carriage.
In the plan view of FIG. 2 in which the carriage cover 12 has been removed, it is seen that the printhead carriage 30 is mounted on a pair of transversely extending slider rods or guides 32 , 34 which in turn are rigidly affixed to the frame of the printer. Also rigidly affixed to the frame of the printer are a pair of tube guide support bridges 40 , 42 from which front and rear tube guides 44 , 46 are suspended. The front tube guide 44 has end portions which extend transversely of the printer and an intermediate section 45 which is angled in a horizontal plane near the left bridge support 40 to provide a clearance area for opening a printhead holddown cover 36 on the carriage 30 when the carriage is slid to a position proximate the left side of the platen 14 so that the printhead holddown cover 36 can be easily opened for changing the printheads.
A flexible ink delivery tube system conveys ink from the four separate ink reservoirs 20 , 22 , 24 , 26 at the left side of the printer through four flexible ink tubes 50 , 52 , 54 , 56 which extend from an ink reservoirs through the rear and front tube guides 44 , 46 to the carriage 30 to convey ink to four printheads on the carriage 30 . The ink tube delivery system may be a replaceable system as described and claimed in co-pending application Ser. No. 09/240,039 filed on Jan. 29, 1999 owned by the assignee of the present invention, the disclosure of which is hereby incorporated herein by reference. The ink is delivered from an ink reservoir to the corresponding printhead by means of an air pressurized system, which by priming air into the reservoir, applies pressure to the ink contained in it, so conveying the ink out of the reservoir through the tube and up the printhead.
At the right side of the printer is a printhead service station 80 at which the printhead carriage 30 may be parked for servicing such as wiping, spitting or priming the printheads.
As seen in FIG. 3, each of the four ink reservoirs 20 , 22 , 24 , 26 is easily accessible from the front of the printer when the reservoir cover 16 (seen in FIG. 1) is open so that the reservoirs can be easily removed to be refilled or replaced with new reservoirs. As is known in the art, three of the reservoirs each contain a different base color of ink such as cyan, magenta and yellow and the fourth reservoir contains black ink so that a high number of colors can be produced as desired during printing.
As best seen in FIGS. 4 and 5, the front and rear tube guides 44 , 46 are of channel configuration with each guide 44 , 46 having a lower flange 60 , 62 which provides a support surface which extends in a common horizontal plane for supporting the ink delivery tubes 50 , 52 , 54 , 56 along its length with the exception of the reverse bend B (FIG. 2) in the tubes to the right of the printer carriage 30 . The ink tubes are preferably bound together in a flexible wear resistant low friction sheath 58 to confine the tubes in a vertical plane and prevent wear as the tubes move in the guides 44 , 46 . The tube bundle and sheath is of sufficient rigidity to be self supporting in the region of the reverse bend B.
The flexible ink delivery tubes 50 , 52 , 54 , 56 and sheath are all permanently connected to a printhead connector 100 which is a relatively rigid plastic part best seen in FIGS. 4 and 9. The ink delivery tubes are preferably made of a linear low density polyethylene. The protective sheath 58 encloses the flexible ink tubes between their permanent connection to the printhead connector 100 and a rigid plastic tube clip 130 which fastens the ink tubes to the rear tube guide 46 at the location shown in FIG. 2 near the left side of the printer. The protective sheath 58 preferably includes wear resistant lubricious ribs 51 , 53 on the top of the upper tube 50 and on the bottom of the lower tube 56 and ribs 55 on the sides of all four tubes 50 , 52 , 54 , 56 which face the front and rear tube guides 44 , 46 . The ribs 51 , 53 , 55 are preferably made from polypropylene containing about 5% aramid fibers and 20% polytetrafluoroethuylene (TEFLON). The material of the sheath 58 is preferably a polypropylene and EPOM compound which is both flexible and fatigue resistant. The above combination of materials for the sheath and ribs has been found to be considerably more quiet than prior art flexible ink delivery systems.
Apertures 70 , 72 having elongated slots 74 , 76 in the vertical wall of the rear tube guide 46 receive mating bayonet clips 132 , 134 on the rear side of the tube clip 130 so that the tube clip may be slid to the right or the left to easily connect or disconnect the clip 130 from the rear tube guide 46 .
The lower tube support flange 60 of the front tube guide 44 is shown in a generally horizontal plane in FIG. 4 but a slight downward inclination of the flange toward the opposite flange 62 of the rear tube guide 46 is desirable to assist in smooth movement of the tube bundle in the front guide. Comparison of FIGS. 4 and 5 shows that the lower flange 60 is slightly downwardly inclined in the FIG. 4 view but is somewhat horizontally shorter and is horizontally oriented in the FIG. 5 view. Reduction in the horizontal length of the support flange 60 as seen in FIG. 5 enables the printhead connector 100 and attached tubes to pass to the side of the flange 60 in the region of the left transversely extending section of the front tube guide 44 . Also as seen in FIGS. 2, 4 and 5 , the rear tube guide has an upper flange which extends substantially along the right half of the rear tube guide 46 , the top flange gradually terminating at an angled section centrally located on the printer. It will be appreciated that there is no relative motion between the rear tube guide and the tubes in the section which is uncovered by the top flange. Similarly, the short section of tubes and sheath extending from the permanent connection to the printhead connector 100 to the lower flange 60 of the front tube guide 44 need not be supported by the lower flanged 60 since the tubes and sheath are self supporting for short lengths in this area and at the reverse bend B of the tubes.
An ink tube clip 130 (FIGS. 6-8) comprises a molded plastic part having four parallel tube channels formed therein. The sheath terminates near the right end of the tube guide 130 and the four ink delivery tubes 50 , 52 , 54 , 56 extend continuously through the channels in the guide 130 to emerge from the left edge of the guide. The guide is provided with foldable upper and lower closure flaps integrally formed with the rear channel-defining wall of the clip 130 and are connected thereto by flexible hinge sections and connectors having inherent resilience so that the doors may be closed over the ink delivery tubes and sheath, the tubes being confined in their respective channels. A resilient hook in the rear wall of the clip 130 engages an aperture in the upper flap to close the flap over the ink delivery tubes. An engagement lip at the lower edge of the rear wall of the clip 130 mates with a complementary hook on the lower edge of the upper flap to securely fasten the flap head hold and hold the tubes in place. A front flap is similarly constructed with a flexible hinge joining it to the channel defining wall of the clip 130 . Complementary hooks on the upper right edge of the channel defining wall of the clip 130 and upper edge of the lower flap securely hold the flap in place to confine the tubes and sheath at the right end of the clip 130 .
The rear side of the clip has integrally molded fasteners thereon which are received in complementary shaped slotted apertures in the vertically extending wall of the rear tube guide as shown.
With reference to FIG. 10, the mechanical part of the ink leak detector will now be described. As it has been said above, the ink delivery system comprises four flexible ink delivery tubes 50 , 52 , 54 , 56 , but for sake of clarity the ink leak detector will be described with reference to just one of them, since the same applies to remaining ones.
When tube 50 breaks, a small crack appears. It more likely to happen in the dynamic zone B of the tube, which is the part that is subject to the reverse bend during the carriage movement. Zones A of tube 50 are the portions that are substantially static while the carriage 30 is moving. As the system is pressurized, the ink is forced to flow through the crack and gets between the tube 50 and the tube sheath 58 , filling it.
The carriage end of the tube sheath 58 is sealed with an O-ring 1010 that has been preferably overmolded to the tube sheath itself. This joint 101 prevents the ink from reaching the carriage 30 .
As one end of the tube 50 is plugged the ink is forced by the pressure, to flow towards the other, opened, end, which is fixed to the printer 10 . In correspondence to the open end of the tube sheath 58 , at a lower position, it is placed an ink collector 1020 , that retains the ink as it drops from the tube sheath 58 by gravity.
The ink collector 1020 comprises two metallic pins or electrodes 1030 , 1040 , triggering the electrical resistance between them. When the ink gets into contact with the pins (and taking advantage of the conductive properties of the ink) the electrical resistance gets reduced, and the ink leak is detected.
When the leak is detected, the printer 10 preferably stops printing and the pump pressurizing the ink into the tube 50 is turned off. So, the system gets depressurized, and the ink in the tubes returns, by gravity, to the ink reservoir 20 . If the user turns off and on the printer, the system continues triggering the resistance and by detecting the leak, stops the printer again immediately.
A System Error message may also displayed on the front panel, advising the user to replace the tubes, or to call the service support.
The above described ink leak detection system can be easily applied to a preferred embodiment wherein four ink delivery tubes are employed, as described with reference to FIGS. 1 to 9 , and a single tube sheath 50 is provided for enclosing all the four ink delivery tubes 50 , 52 , 54 , 56 . By sealing the carriage end of the tube sheath 50 , by means of four O-rings, one per each ink delivery tubes, overmolded to the tube sheath 50 , the ink leaked from any of the four ink delivery tubes is conveyed within the tube sheath 50 towards its open end and then into the ink collector 1020 .
The skilled in the art may appreciate that in a further embodiment, wherein more ink delivery tubes are employed, e.g. in six or eight color printers, the above system can still be applied, with few changes. For instance the ink delivery tubes may be grouped into independent sets, e.g. 3 tubes and 3 tubes (in a 6 color printer), or 4 tubes and 4 tubes (in a 8 color printer) or any other combination depending on the kind of constraints generated by the printer design, each set being enclosed by an independent tube sheath 50 . The two independents tube sheaths may lay side by side and may be guided by a guide system similar to the one described above. In case of leakage, by sealing the carriage end of both the tube sheaths, the ink is, again, conveyed to the open end and then into the same ink collector, this time placed in correspondence of the open ends of both the tube sheaths. As an alternative, two ink collectors may be located within the printer, each one collecting the ink coming from one of the two tube sheaths, so that in case of breakage of ink delivery tube(s) in only one set, the failing ink delivery tube set can be more easily identified and replaced.
With reference to FIG. 11, the electrical circuit of the ink leak detection system will be now described. As described above, the tubes system forces the ink to flow towards the ink leak collector 1020 in case of a leakage. In collector 1020 , the two electrodes 1030 , 1040 , being integrated in a resistance divider network, are used to measure the resistance generated by the means which allows an electrical connection between them. In case of no leakage there will be air between the two electrodes and the resistance measured will be very high (>10 12 Ω). In case of leakage, the collector will contain ink and a potential short circuit between both electrodes is generated through the ink. To summarize, the ink leak detector measures the resistance in the collector, if this resistance is below a certain threshold value then the system will assume there is ink in the collector and the machine is stopped.
In order to distinguish between the resistance of the air (>10 12 Ω) and the resistance of the ink (more often comprised between 100 KΩ and 1 MΩ) a number of experiments has been performed by the Applicant. An approximation of the ink resistance indicates that the resistance measured will be around tenths of kilo ohms.
The resistance between both electrodes depends a lot on parameters like the contacts material, the ink resistance, the amount of ink covering the leads, the path the current has between both and so on. As an approximation we could consider that the resistance is caused by a right section of ink between the electrodes, then according to the present example, when there is 3 cc of ink in the collector, the length of electrodes covered by ink is 3.6 mm, then the resistance can be calculated by means of the following formula: R = 1 σ · l A · η
where σ is the ink conductivity, for the nominal case ink (the value assumed is 1 milioh/cm), 1 is the distance between electrodes 1030 , 1040 , in this example equal to 12 mm. A is the surface section of one electrode in contact with the ink, in this example 0.7 is the width of each electrode. Finally η is a correction factor (due to several factors like the real value of the conductivity for each ink, the real surface contact, etc). Therefore: σ = 10 - 3 mhos / cm l = 1.2 cm A = 0.07 cm · 0.38 cm = 0.0266 cm 2 R = 1 10 - 3 · 1.2 · η 0.0266 ≈ 31 K Ω · η
From statistical measurements done by the Applicant the value of the correction factor is comprises between 8 and 20 for the black ink and 4 to 10 for the colors ink, that's the resistance value is preferably below 1 MΩ for most of the types of ink. The air resistance is always higher than this value for the specific mechanic design (electrodes distance about 12 mm and electrodes length about 20 mm) even in worse case conditions (maximum relative humidity).
Accordingly, the detection of an ink leak may be carried out by measuring the voltage in a resistance divider network, as shown in FIG. 11, composed by the collector resistance 1110 , corresponding to the interaction of the two electrodes 1030 , 1040 , and a fixed resistance 1120 of 2 MΩ. The network is supplied at 2.5 V. This voltage is compared using a comparator 1130 with a fixed reference voltage of 1.25 V. When the voltage measured in the fixed resistor 1120 is higher than the reference voltage then the comparator 1130 output will change and a signal to the system is generated.
The circuit above is then placed on a board, located within the printer and connected to the electrodes 1030 , 1040 through two connectors on the board itself. These connectors are then protected from humidity and condensation by some conventional insulating resin.
Those skilled in the art may appreciate that the circuit design above may be modified in many ways, e.g. varying the distance between the electrodes or the size of their surface, but the formula for calculating the resistance between the electrodes can still be used as described for determining the appropriate values for the fixed resistance 1120 and for the fixed reference voltage.
While exemplary and preferred embodiments of the invention have been shown and described, it will be appreciated by those skilled in the art that various modification and revision be made without departing from the spirit and scope of the invention as set forth in the following claims.
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An inkjet printing device has a frame, a transversely moveable printhead carriage, carrying a plurality of inkjet printheads, mounted for reciprocating movement on the frame, ink supply reservoirs mounted on the frame and flexible ink supply tubes for delivering ink from each of the ink reservoirs to a corresponding inkjet printhead. The device further includes an ink leakage detection system with an ink collector for collecting an ink leak from the ink supply tubes, and a sensing circuit coupled to the collecting unit, capable of detecting the presence of ink in the ink collector. A method of detecting the ink leak in the inkjet printing device includes the step of: conveying the ink leak from an ink delivery system to the ink collector, both comprised by the inkjet printing device; sensing when the ink is present in the ink collector; providing the information that an ink leakage is present in the device; and stopping the device.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims the benefit of U.S. Provisional Application No. 61/270,344, filed Jul. 7, 2009, which is a continuation-in-part of International Application No. PCT/US2008/003374, filed Mar. 14, 2008, both of which are incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to input devices for electronics and, more particularly, to a suspension for a touch sensitive input panel's or display's touch surface especially suited for use in eBook readers, cellular phones and personal digital assistants (PDAs), PC Tablets, as well as laptops, PCs, office equipment, medical equipment, TVs Monitors, or any other device that uses touch sensitive displays or panels.
2. Description of the Background
Touch sensitive screens or touch surfaces can detect the application of fingers and other passive objects. Touch surfaces are gaining in popularity and have been deployed in many products in recent years. A number of different technologies have been used to create touch surfaces, such as resistive, capacitive, infrared, surface acoustic wave (SAW), and others. Resistive pads, for example, comprise two conductive plates pressed together. The disadvantage of a resistive pad is that the resistive membrane material will wear out, initially resulting in further reduced clarity followed by dead spots. In addition, the production yield is typically rather poor, and the technology has a few disadvantages such as a fixed (non-user adjustable) actuation force and the light throughput through the resistive membranes is typically only around 70% to 75%.
Capacitive touch screens/pads operate by measuring the capacitance of the passive object to ground, or by measuring the alteration of the transcapacitance between different sensors. An example of a capacitive touchpad is described in U.S. Pat. No. 5,495,077 to Miller. Capacitive pads are relatively expensive to manufacture compared to resistive pads, and can only detect objects with sufficient capacitance. Small objects, such as the end of a regular stylus or pen, do not have enough capacitance to ground or transcapacitance to be detected by a capacitive touchpad. The actuation force can also not be set, and the force may be as low as a 0 gram force, that is, the touch screen registers a touch even before the user's finger touches the screen. This often leads to difficulties in implementing certain end-user features, such as handwriting recognition.
SAW devices emit sound along the surface of the pad and measure the interaction of the passive object with the sound. These devices work well, but are generally much too expensive for general applications. Infra red light based displays work in a similar fashion, but this technology typically adds a large size and price.
Finally, there are devices that use force sensors to measure the location and magnitude of the force exerted by the passive object on the touchpad. Force sensing technology is very interesting from both feature and cost perspectives. A force sensitive touchpad will sense force applied by any sort of passive object, regardless of the electrical conductivity or composition of the object. Such devices were originally described in U.S. Pat. No. 3,657,475 to Peronneau et al. and U.S. Pat. No. 4,121,049 to Roeber. These devices measure the forces transmitted by the touchpad to a fixed frame at multiple points, for example, at the corners of the pad. Roeber discloses a mathematical formula for deriving the position and magnitude of the force applied by a passive object from the forces measured at the multiple points.
For example, U.S. Pat. No. 4,511,760 to Garwin et al., issued Apr. 16, 1985, shows a force sensing data input device responding to the release of pressure force. The input surface is provided with a transparent faceplate mounted on force-sensing piezoelectric transducers. Preferably, four piezoelectric transducers are provided, one at each corner of a rectangular opening formed in the frame. To determine the point of application of force on the input surface, the outputs of the four transducers are first summed. To constitute a valid data entry attempt, the sum must exceed a first threshold while the user is pushing on the input surface. When the user releases his finger, a peak of the sum is detected, which is of opposite polarity from the polarity of the sum in the pushing direction. The individual outputs of the four sensors at the time that the peak of the sum occurs are used to calculate the point of application of the force.
United States Patent Application 2003/0085882 by Lu published May 8, 2003, shows a touch pad device having a support layer with a plurality of strain gauges in a matrix configuration. A touch layer is disposed on top of the strain gauge matrix. The touch layer is joined to the top of the strain gauge matrix. Sensor wires connect the strain gauges to a processor that is programmed with an algorithm to measure the location and pressure of simultaneous, multiple touches.
United States Patent Applications 2004/0108995 and 2004/0021643 both by Hoshino et al. show a display unit with touch panel mounted above a display via four differentially-mounted sensors. The pressure sensors detect force with which a pointing device such as a finger pushes the panel surface, in real time. The force with which the pointing device such as a finger pushes the panel surface is found from the following equation irrespective of the pointing position: P=a+b+c+d−a0+b0+c0+d0, which equation detects dragging of a cursor.
United States Patent Application 2005/0156901 by Ma et al., issued Jul. 21, 2005, shows a touch screen display system with a display screen and overlying touch surface. An imaging system determines an angular position on the touch surface of the object coming in contact with the touch surface.
United States Patent Application 2006/0016272 by Chang, published Jan. 26, 2006, shows a thin film touch pad with opposed sensor elements that generate an electrical signal that is proportional to both the applied pressure and the surface area at the location of the applied pressure. As a result of the complementary and overlapping orientation of these sensor elements, the first and second sensor elements generate an asymmetric pair of signals that uniquely define the applied pressure by position and magnitude.
U.S. Pat. No. 6,879,318 by Chan et al., issued Apr. 12, 2005, shows a touch screen mounting assembly for a liquid crystal display (LCD) panel including a bottom frame having a seated backlight panel and a plurality of mounted pressure-sensitive transducers, an LCD panel, and a top frame for exerting pressure when mounted to the bottom frame such that a plurality of compressible springs biases the LCD panel towards the bottom frame when touched or contacted by a user. The claims require the bottom and top frame assembly with backlight panel mounted therein on springs, and an overlying LCD panel.
The market success for force based touch screens and pads has so far been very limited for various reasons. Current implementations employ complex mechanical structures and appropriate force-sensing sensors. A method to overcome the mechanical complexities (promising a low cost and small size penalty) is described in International Application No. PCT US2008/003374 filed Mar. 14, 2008, which employs a figure-8 suspension concept to ensure that the touch screen will not move in the x-y plane. This is therein illustrated in FIG. 1 which shows the profile of how the wire or line ( 15 ) is wrapped around the touch surface ( 10 ) and the back surface ( 14 ) in a figure-8 loop. The line ( 15 ) is wrapped around all 4 sides, creating 4 separate figure-8 loops or one combined (using 4 or 1 lines). The line suspension can be designed in a number of variants, where the line may be wrapped around the surfaces as in FIG. 1 , or it may secure the surfaces through hole or channels into the corner or the surfaces, or connected to wire holders which are fastened to the surfaces. Either way, the principles remains the same, the built-in tension in the line pulls the touch surface ( 10 ) towards the base plate ( 14 ) applying a stable, pre-loaded force onto the 4 force sensors ( 41 ). The forces in the string is also centering the touch plane ( 10 ) in relation to the base plate ( 14 ) as the forces in the x-y plane applied to the 4 corners are directed to the center of the touch plane. This centering force will allow the touch plane to remain centered and not move in the x-y plane, but allow for the small friction free movement required in the z-direction, typically less then 0.1 mm distance when using a piezo resistive sensor (other force sensors may require a larger z-direction movement).
The foregoing configuration provides a good mechanical suspension with a close to zero loss in the touch force, yet the device is free to move frictionless in the z-direction thereby ensuring that all of the touch force will be distributed to four force sensors. Moreover, the suspension is very low cost in terms of components. However, the assembly process is not optimal. In addition, it is difficult to apply a dust or water seal which typically requires a rubber or silicon material to touch the touch lens, and the seal must typically also be tailor made as well as tested and verified for each new design.
It would be greatly advantageous to provide a suspension solution that preserves the mechanical aspects of the force based touch screen system in a way where the mechanical characteristics of the system described above are maintained, but with a design that is optimized for both high volume production as well as for a built in low cost and high performing water seal. The same platform components should also be capable of accommodating different sensor sizes/shapes, should allow for a more cost efficient suspension mechanism, and should be reusable from one product implementation to the next.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present innovation to allow for cost efficient design and manufacturing of force sensing sensor-based touch screen products of different sizes, designs, and applications with one and the same conceptual component.
It is another object to provide a suspension solution that can be implemented and assembled at a low cost, and yet support different sensor types and sizes without any conceptual changes and a minimum of component changes.
It is another object to provide a suspension solution that also serves as water seal for the touch screen.
It is another object to provide a suspension solution that is less sensitive for external interference, such as vibrations.
These and other objects are accomplished by a mechanical suspension platform for sensor-based touch surface products that uses a suspension membrane component, for example, a flexible suspension membrane attached between the touch surface and frame for maintaining said touch surface in a suspended configuration, whereby it is afforded frictionless movement along a z-axis but is restrained from movement along the x-y plane.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which:
FIG. 1 illustrates a touch screen suspended to a rigid frame through a thin membrane, according to the present invention.
FIG. 2 illustrates a touch screen suspended to a rigid frame and pre-loaded through a thin membrane as in FIG. 1 , from a side view.
FIG. 3 illustrates an alternative embodiment of a touch screen suspended to a rigid frame through a thin membrane, from a side view.
FIG. 4 illustrates the alternative embodiment of a touch screen suspended to a rigid frame through a thin membrane as shown in FIG. 3 , from an enlarged side view.
FIG. 5 illustrates the touch screen of FIG. 3 suspended to a rigid frame and pre-loaded through a thin membrane, from a top view.
FIG. 6 illustrates the alternative embodiment of a touch screen suspended to a rigid frame through a thin membrane, from an enlarged side view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is a suspension platform for a touch sensitive input panel or display having a touch surface, which is especially suited for use in cellular phones, personal digital assistants (PDAs), and PC Tablets, as well as laptops, PCs, office equipment, medical equipment, TV Monitors, or any other device that uses touch sensitive displays or panels.
FIG. 1 is an exploded view of a suspension platform according to one embodiment of the present invention incorporated in a touch sensitive input display for an eBook reader, and FIG. 2 is a side view.
In an embodiment, an eBook reader comprises an ePaper display (EPD) that is a touch surface 55 defining an x-y plane having a normal z-axis. The reader housing incorporates a bezel 50 that defines a touch plane on the touch surface 55 . The bezel 50 is held in place by connecting it to a back housing 61 (see FIG. 2 ) of the eReader housing. The bezel 50 is also connected to a thin suspension membrane 53 . The bezel 50 sits atop the suspension membrane 53 , which in turn sits atop the touch surface 55 . Because the touch surface 55 is an EPD that is a very thin and rather fragile, the touch surface 55 is strengthened and made more rigid by adding a display support 57 . The display support 57 is a flat rigid plate that bears against four under-mounted differential pressure-sensors 58 . The sensors 58 are mounted on a base support 60 , such as a standard printed circuit board (PCB). The base support 60 provides the rigidity and flatness required for the sensors 58 . Depending on the product implementation, the base support 60 may be seated directly onto the back housing 61 (see FIG. 2 ) of the unit, or if a double sided PCB is used for the base support 60 , space may be available between the bottom of the base 60 and the back housing 61 ( FIG. 2 ) of the unit. As the bezel 50 is mounted with the back housing 61 of the unit, the bezel 50 and the back housing 61 are forced together, which results in the bezel 50 applying a calibrated preload force through the membrane 53 to the touch surface 55 and display support 57 onto the sensors 58 .
These differentially-mounted sensors 58 are connected through the base support 60 to an electronic device processor. This way, when a user touches the touch surface 55 at some (x,y) position, the force is transmitted through the touch surface 55 and the display support 57 to the four under-mounted differential pressure sensors 58 , for example, piezo-resistive force sensors. Once the force is applied to the sensors 58 , a change in output voltage is generated and continuously sent to the processor, where the output is registered and processed. The exact (x, y) “touch-coordinate” on the touch surface 55 is calculated.
As seen in the inset of FIG. 1 , the suspension membrane 53 is a substantially rectangular elastomeric frame conforming to the peripheral shape of the touch surface 55 . The bezel 50 is only in contact with the touch surface 55 through the suspension membrane 53 . In the illustrated embodiment, the suspension membrane 53 is formed with three contiguous walls and is inwardly open, leaving a hollow interior air gap. The size of the gap is dependent on the elasticity of the membrane 53 , the size of the touch surface 55 , and the required pre-loading force. The suspension membrane 53 acts like an accordion. The bezel 50 presses down on the membrane 53 that presses on the touch surface 55 , providing the pre-loading. Membrane 53 facilitates frictionless movement of the touch surface 55 towards the sensors 58 (along the z-axis) and yet restricts movement away from sensors (in the x-y plane). Moreover, the membrane 53 creates a dust and water tight seal for the unit.
In an alternative embodiment, rather than a bezel 50 of the frame pressing down onto the touch surface 55 via membrane 53 , the bezel pulls the membrane and touch screen down onto the sensors.
FIGS. 3 and 4 illustrate an alternative embodiment of a touch sensitive display or panel having a touch screen in which the bezel 150 pulls the membrane 153 down, thereby pulling the touch screen 155 down on the sensors 158 .
Here the above-described bezel 50 and back housing 61 are combined in a fixed frame 160 defining an outside structure, such as the housing of the product. There is a thin gap 152 between the frame 160 and the touch surface 155 . A thin membrane 153 spans the gap 152 , and the touch surface 155 is only connected to the fixed frame 160 through the membrane 153 . The size of the gap 152 is dependent on the elasticity of the membrane 153 , the size of the touch surface 155 , and the required pre-loading force. The membrane 153 fixes the touch surface 155 relative to the frame 160 in the x-y plane. The membrane 153 may be a strip of plastic, rubber, silicon, adhesive tape, or similar material depending on the specific characteristics required of the actual product design. The membrane 153 can be kept very thin since it can be applied completely around the touch surface 155 . If a side-force is applied to the touch surface 155 , the 2 parallel sides and the opposite side of the membrane 153 resist the movement, virtually eliminating any side movement.
FIG. 5 is a top view of the system of FIGS. 3 and 4 . The membrane 153 holds the touch surface 155 in place within the outside frame 160 , allowing for small movements in the z-direction while only creating minimal friction forces. As the required movement is typically in the area of 0.01 to 0.05 mm, the forces created from the stretching of the membrane 153 are minimal, if any. Other force sensors, such as traditional strain gauges may require a larger movement in the z-direction, and gap 152 and membrane 153 may be adjusted accordingly. In addition to the x-y-plane control, the suspension solution must also provide a preloading force to ensure that the touch surface 155 is always resting on the force sensors 158 and to reduce jitter from physical vibrations. The force applied in the z-direction towards the sensors 158 from the elasticity/spring effect from the membrane 153 will in most designs be sufficient, but if required, additional pre-loading may be applied by a spring, cantilevered bender, or similar spring-like component 154 . Even when using a thin, elastic membrane 153 , the touch surface 155 is kept fixed in the x-y plane. The membrane 153 provides no support in the z-direction, especially for small movements (<0.1 mm), which affords the touch surface 155 a very close-to-force and friction free movement in the z-direction (again <0.1 mm) as a force is applied through a user's touch.
FIG. 6 illustrates the alternative embodiment of a touch screen suspended to a rigid frame through a thin membrane, from an enlarged side view. In this embodiment, the membrane 153 is connected to the bottom of the touch surface 155 —the side opposite the side of the touch surface 155 that is touched. The membrane 153 pulls the touch screen 155 down on the sensors 158 .
Although in the illustrated embodiments, the touch surface is a surface of the display module, the touch surface may be a separate component. The present invention is not limited to any particular display module and may include, for example, EPD, LCD, OLED or other display modules.
One skilled in the art should understand that the material options are rather wide, and the complete system; frame (base), membrane, and touch screen can even be manufactured from one material; however, in most applications the three components will consist of different materials, such as a metal incased glass plate assembly for the touch surface, plastic product housing or bezel for the frame, and a plastic membrane part fixed onto the frame and display through strong, permanent adhesive.
This invention provides a few important benefits over the existing wire solution. The suspension membrane 53 , 153 will very effectively seal the touch surface to the outside frame. It is impossible for humidity, dust, or liquid to penetrate in between the touch surface and the frame, even though they are mechanically not fixed connected.
The touch sensitive display or panel must have a touch surface and a base plate or base frame that holds the suspension system, which keeps the touch surface fixed in x-y plane with free micro movement in the z-direction. With the membrane approach, there is no need to add mechanical structures in order to fix the wire assembly to the touch surface and the base plate. This can further reduce the overall building height of the final product, which is extremely important from a touch sensitive display or panel competitive position.
The suspension membrane 53 , 153 will also provide required pre-loading force in the z-direction for better sensor performance and minimizing negative effects from vibration and movement impact on the touch screen system.
This suspension mechanism, independent of which implementation is used, requires a very large force to further move the display away from the sensors. This will then eliminate a problem sometimes occurring with the wire approach in which the weight of the display overcomes the preloading force when the unit is held up-side down and one or multiple sensors lose contact with the display, resulting in an invalid touch screen input.
Finally, the manufacturing and the placement of the membrane is optimal for high volume manufacturing. The material costs are extremely low, and the manufacturing operation is similar to existing operations, such as placing a dust seal into a product.
Having now fully set forth the preferred embodiment and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims.
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A suspension system for mounting a touch surface of a pressure sensitive touch display or panel. The suspension system comprises a frame and a flexible suspension membrane connected to the touch surface and the frame, the membrane allowing frictionless movement of the touch surface along the z-axis and resisting movement of the touch surface within the x-y plane. At least one force sensor is connected beneath the touch surface, whereby the touch surface is pre-loaded against the at least one force sensor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the amino acid peptide hormone standards and, more specifically, to the use of parathyroid hormone (PTE), an 84 amino acid peptide hormone for diagnosing calcium metabolism disorders.
2. Description of the Related Art
Intact parathyroid hormone (PTH) is an 84 amino acid peptide hormone produced by the parathyroid gland. Since PTH maintains calcium homeostasis, its measurement is an important aid in the diagnosis of calcium metabolism disorders. Decreased serum calcium levels result in increased PTH secretion, causing increased absorption of dietary calcium, decreased renal clearance, and mobilization of skeletal calcium stores. In conjunction with calcium levels, PTH quantization can help distinguish between normal patients and patients with hyperparathyroidism, hypoparathryoidism or hypercalcemia of malignancy.
A diagnostic kit usually employs an immunometric method to measure an unknown sample read off a curve generated using a series of standards. For kits employing hormones as the standards, the hormones are prepared in a serum or buffered serum matrix.
Typically, PTH standards in a kit are constituted from freeze-dried PTH to achieve desired stability. Testing has shown that PTH spiked at 50, 500, and 1500 pg/mL into human serum and buffered bovine serum albumin matrix has a recovery of approximately 70% and 80%, respectively, after a three day, 37° C. stability test. The recoveries for acceptable standards are within 100+/−10%.
The prior art recognizes the limitations of using freeze-dried biological materials, such as PTH, for standards. The freeze-drying PTH results in a loss of activity. Errors in preparation of the standard occur due to reconstituting the lyophilized PTH in terms of volume and mixing to homogeneity.
Lyophilizing the material used as standards creates additional problems. Lyophilization is a capital and energy intensive process, making it costly. Further, the batch size of the lyophilizer also limits the quantity of the standard produced. Additionally, a low quality batch of freeze-dried product results in a large scrap cost.
Stability of standards may also be achieved through the use of additives that preserve biological material. For example, additives provide a protective function against the adverse effects of adsorption onto glass. Additives may preferentially bind metal ions or other functional groups, or displace water to preserve activity.
Unfortunately, the range of preservation additives is very wide and includes substance as diverse as substrates, specific ligand, glycerol, sugars, polyethylene glycols, detergents, and chelators. The wide range of preservation additives results in intensive research to determine appropriate combinations and quantities.
The prior art recognizes a need for a liquid PTH standard that has a long—at least nine months —shelf life that does not require freeze-dried PTH.
SUMMARY OF THE INVENTION
A solution comprising a non-reconstituted hormone and a preservative that has a useful shelf life of at least nine months at 4 degrees C. has been discovered. In aspects of the invention, the solution has a useful shelf life of at least six months at 4 degrees C.
In further aspects of the invention, the solution comprises a non-specific binding reducer. The solution may be a buffered aqueous solution with a pH greater than 7.0. The solution may be buffered with phosphate.
In a further aspect of the invention, the hormone is parathyroid hormone, but other aspects of the invention may have other hormones.
In a further aspect of the invention, the preservative is polyvinyl alcohol, dissolved EDTA di-sodium salt, or dissolved sodium molybdate. In a still further aspect of the invention, the preservative, expressed as a percentage of the solution, comprises less than 1% polyvinyl alcohol, less than 0.5% dissolved EDTA di-sodium salt, and less than 1% dissolved molybdate. In an even further aspect of the invention, the preservative, expressed as a percentage of the solution, comprises approximately 0.5% polyvinyl alcohol, approximately 0.17% dissolved EDTA di-sodium salt, and approximately 0.7% dissolved molybdate.
In an aspect of the invention, a diagnostic test kit comprises a plurality of standards of known percentages of a non-reconstituted hormone in a solution comprising a preservative, as described above. The kit also comprises a solid phase coated with anti-hormone antibody and a solution of labeled antibody of the hormone.
In a further aspect of the invention, the labeled antibody has acridinium ester label. Other aspects may have other suitable labels. The hormone may be parathyroid hormone or any other suitable hormone.
In an aspect of the invention, a process for assaying a sample for a hormone comprises the step of providing a plurality of standards having varying levels of a non-reconstituted version of the hormone and a preservative in a matrix wherein the standards have a useful shelf life of at least nine months at 4 degrees C. In other aspects of the invention, the standards may be any suitable variation of the solutions described above. In a next step of aspect of the invention, quantities of the plurality of standards and the sample are delivered to containers, respectively. Then, additional quantities of an labeled antibody of the hormone are delivered to the containers, respectively, whereby each container comprises a solution. A solid phase coated with an additional antibody of the hormone is placed into the solution in each container. The solutions are incubated and the solid phase is washed and measured for the labeled antibody of the hormone on the solid phase.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE is a schematic representation of a parathyroid hormone diagnostic kit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in more detail to the FIGURE, a diagnostic test kit 10 for performing an intact parathyroid hormone (PTH) assay comprises PTH antibody coated beads 12 , acridinium ester labeled PTH antibody solution 14 , six standards 16 - 21 , two controls 22 - 23 , and a saline wash concentrate 24 , all of which are stored in appropriate containers. Other kits may have other materials, including more or fewer standards and controls. In the preferred embodiment of the invention, the kit is used in conjunction with a luminometer, but any suitable photomultiplier tube to measure emitted light or spectral reading instrument may be used. Other embodiments of the invention may have any suitable label on the hormone antibody and any suitable instrument for measuring the label, such as a radio isotope label and an instrument that reads the radio isotope.
The PTH standards 16 - 21 and controls 22 - 23 contain a non-lyophilized PTH in a substantially non-protein matrix with preservatives. Other embodiments of the invention may use any non-reconstituted PTH or other hormone in the diagnostic test kit 10 . In preferred embodiments of the invention, the standards 16 - 21 and the controls 22 - 23 have a shelf life at 4 degrees C. of at least six months, or, more preferably at least nine months, or, even preferably at least a year, as a result of the preservatives. Prior art diagnostic kits with an extended shelf life at 4 degrees C. employed hormone standards and controls that required reconstitution, such as freeze-dried standards and controls.
In a preferred embodiment of the invention, the matrix comprises phosphate buffered saline, but other embodiments of the invention may have other solutions, both buffered and non-buffered. In a preferred embodiment of the invention, the preservatives are polyvinyl alcohol, EDTA di-sodium salt, and sodium molybdate. In a more preferred embodiment of the invention, there is less than 1% polyvinyl alcohol, less than 1% sodium molybdate, and less than 0.5% EDTA di-sodium salt dissolved in the buffer solution. In a highly preferred embodiment of the invention, there is approximately 0.5% polyvinyl alcohol, 0.7% sodium molybdate, and 0.17% EDTA di-sodium salt, dissolved in the buffer solution.
In an embodiment of the invention, a non-specific binding reducer such as a non-ionic detergent is employed. In a preferred embodiment of the invention, the non-ionic detergent is t-octylpheoxypolyethoxyethanol sold under the brand name TRITON X-100 by Sigma of St. Louis, Mo., and is added to the standards 16 - 21 and controls 22 - 23 to correct for high non-specific binding of the non-protein matrix. In a preferred embodiment of the invention, less than 1 .5%t-octylpheoxypolyethoxyethanol is added to the matrix, and in a highly preferred embodiment of the invention, 0.5%t-octylpheoxypolyethoxyethanol is added to the matrix.
In a preferred embodiment of the invention, the standards 16 - 21 and the controls 22 - 23 are made by spiking the matrix with concentrated PTH solution. In a preferred embodiment of the invention, the standards 16 - 21 are spiked such that the levels of PTH therein are approximately 0, 5, 15, 50, 150 and 1500 picograms/mL respectively. Other embodiments of the invention may have more or fewer standards and the standards may have other percentages of PTH. In an embodiment of the invention, the controls 22 - 23 have PTH levels within the range of the standards 16 - 21 .
In a more preferred embodiment of the invention, the concentrated PTH solution is made by compounding the PTH into the solution of the matrix. In a more highly preferred embodiment of the invention, the solution comprises the phosphate buffered saline earlier described.
In another embodiment of the invention, the concentrated PTH solution required to make the standards and controls is prepared in the above matrix with preservatives and TX100 along with a very small amount of PTH free human serum. This alternative embodiment results in a relatively low percentage of protein that is required to reduce the non-specific binding to a level acceptable for this assay in order to read the low patients correctly. In a preferred embodiment of the invention, the standards and controls are spiked with the concentrated PTH solution such that the standards and controls contain 2% of human serum.
The PTH antibody coated beads 12 are polystyrene beads coated with PTH goat polyclonal antibody. In an embodiment of the invention, there are 100 beads of suitable size. Alternatively,any other suitable solid phase, as is well known in the art, coated with the PTH antibody may be used. The acridinium ester labeled PTH antibody solution 14 is chemiluminescent labeled PTH goat polyclonal antibody in a buffered protein solution. In an embodiment of the invention, 10 mLs of the solution 14 is provided in the kit 10 . In the preferred embodiment of the invention, there is 50 mLs of saline wash concentrate 24 .
Other materials needed to perform the test may include 12×75 mm borosilicate glass tubes, a test tube rack, 100 μL and 200 μL precision pipettors, 100 μL and 500 μL repeating dispenser, a trigger set, luminometer performance controls, reference control sera, a bead dispenser capable of dispensing 6 mm beads, distilled or deionized water, a timer, a mixer, film to cover the tubes, a luminometer, a bead washer capable of washing 6 mm beads or repeating dispenser capable of delivering 2 mL, and a rotator capable of maintaining 180±10 rpm. The trigger set is composed of a trigger 1 and a trigger 2 . The trigger 1 has 0.1N nitric acid and 0.325% hydrogen peroxide. The trigger 2 has 0.25N sodium hydroxide and 0.125% of a detergent, cetyltrimethylammonium chloride. The acridinium ester on the acridinium ester labeled PTH antibody solution 14 emits light under alkaline oxidation and the trigger set serves this purpose.
The assay procedure for analyzing a patient sample involves bringing the kit 10 to room temperature. All liquid components of the kit and all samples are mixed by gentle inversion. The saline wash concentrate 24 is diluted appropriately with the distilled or deionized water to have a concentration of 0.9% sodium chloride.
Continuing the assay procedure, the test tubes (not shown) are appropriately labeled. 200 μL of the standards 16 - 21 , the controls 22 - 23 , and the patient sample are delivered directly to the bottom of a respective test tube. 100 μL of antibody solution 14 is added to the bottom of each test tube and vortexed gently to avoid foaming. Next, one bead 12 is added to each test tube. In a preferred embodiment of the invention, the bead 12 is added with minimal splashing. In a more preferred embodiment of the invention, the test tube is tilted to enable the bead 12 to gently enter the solution in the test tube.
In a next step of the procedure, the liquid filled test tubes are incubated on the rotator (not shown) at 180±10 revolutions per minute (rpm) at room temperature for two hours. In a saline wash step of the assay, the beads are washed three times in an automated washing station, using 2 mL of working saline solution, after incubation. In an alternative embodiment of the invention, the beads may be manually washed. The manual washing step comprises aspirating the tubes, adding three mL of saline solution to the tubes, aspirating the tubes, and repeating three more times the adding and aspirating steps.
Next, each bead is counted in the luminometer using trigger solutions 1 and 2 for two seconds. In a preferred embodiment of the invention, the standards 16 - 21 , the controls 22 - 23 , and the patient samples are assayed in duplicate. The relative light unit read from the luminometer for the duplicate samples is averaged and used for the reduction of data and calculation of the results using techniques known in the art.
Borosilicate glass test tubes are used in a preferred embodiment of the invention due to their inherently low luminescence background and low non-specific binding characteristics.
Patient samples that are greater than the highest standard 21 are diluted with the zero standard 16 and reassayed with the result being multiplied by the dilution factor.
In a preferred embodiment of the invention, the assay should be performed on serum samples. Other embodiments of the invention may use EDTA plasma. Duplicate assays require 400 μL of serum. For a more accurate comparison with normal values, a fasting morning serum sample should be obtained. The blood sample is collected in a red-top venipuncture tube (no additives) and allowed to clot. The sample is centrifuged, preferably in a refrigerated centrifuge, and the serum is separated from the cells. The sample should be frozen immediately (−20° C. or below) or stored as outlined below.
STORAGE CONDITION OF PATIENT'S SERUM
TIME
At room temperature after collection
2 hours
Refrigerated at 4° C.
8 hours
Frozen at −20° C.
4 months
Frozen at −70° C.
11 months
There are other embodiments of the invention that may use the hormones stored with preservatives having an extended shelf life and the hormones were not previously freeze-dried or otherwise preserved in a manner that requires reconstitution for standards and controls. An example of such an embodiment is an immunoradiometric assay of intact PTH (IRMA of intact PTH). In an IRMA of intact PTH, the standards, controls, and samples are incubated with a tracer containing an antibody label using radio isotope iodine 125 and a solid phase, such as the above mentioned polystyrene beads coated with an PTH antibody. The incubation is performed with the materials being stationary at room temperature for 20 to 24 hours. The solid phase is washed twice with 2.0 mL of working wash solution and counted in a gamma counter for 1 minute. In an embodiment of the invention for the IRMA of intact PTH, the standards and controls have a buffered human serum matrix.
In another embodiment of the invention, an intact PTH diagnostic procedure involves delivering 150 μLs of two calibrators, two controls, samples, and 50 μLs of assay buffer and 25 μLs of acridinium ester labeled antibody solution into a cuvette strip. The strip is transported into an incubator chamber and incubated for 20 minutes at 37° C. After the initial incubation, 25 μLs of biotinylated antibody solution and 25 μLs of streptavidin coated magnetic particles are added to each well and the incubation is prolonged another 10 minutes. Then, the wells are washed, aspirated with the particles held to the bottom of each well with magnets, triggered, and read in a measuring chamber. This embodiment may have a reagent cartridge that holds all the reagents that go into the reaction such that the procedure may involve an automatic pipette machine. In this embodiment of the invention, the reagent cartridge and the calibrators/controls may be provided separately as opposed to being in the same kit.
In other embodiments of the invention, other hormones may be kept in a substantially non-protein matrix with preservatives. Still further embodiments of the invention may be kept in a substantially non-protein matrix with preservatives and a non-specific binding reducer. In other embodiments of the invention, diagnostic test kits may contain hormones kept in the substantially non-protein matrices described herein.
Although presently preferred embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught, which may appear to those skilled in the pertinent art, will still fall within the spirit and scope of the present invention, as defined in the appended claims.
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A solution of a non-reconstituted hormone and a preservative having a useful shelf life of at least six months, and, in some circumstances, at least a year. A series of solution of varying levels of the non-reconstituted hormone may be in a test kit and used in a process to determine the level of the hormone in a patient sample. In an aspect of the invention, the hormone is parathyroid hormone. The preservatives may be polyvinyl alcohol, a dissolved EDTA salt, or dissolved sodium molybdate. The hormone may be in an aqueous or a buffered matrix containing very little protein and substantial amounts of TX100 to reduce non-specific binding. The solution is incubated with a solid phase coated with an anti-hormone antibody and a labeled hormone antibody. The solid phase is read using a suitable device for measuring the labeled hormone antibody. An example of a labeled hormone antibody is an acridinium labeled hormone antibody that is read using a light reading device.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to a novel tobacco composition and to the process for the treatment of smoking tobacco for cigars, cigarettes and/or tobacco or pipes and to other smoking products made with tobacco.
(2) Description of the Prior Art
It has long been known that a large number of products of combination found in tobacco smoke are toxic. Included among these undesirable tobacco smoke components are polycyclic aromatic compounds and their heterocyclic analogs. The highly carcinogenic effect of some polycyclic aromatic hydrocarbons is well-documented. (Smoking and Health, Report of the Advisory Committee to the Surgeon General, U.S. Public Health Publication No. 1103, Ch. 9, p. 142-146 (1963)) A specific polycyclic aromatic compound which merits special attention is benzo(a)pyrene (occurs as 1,2-benzopyrene; also referred to as 3,4-benzpyrene and benzo(e)pyrene and 4,5-benzopyrene), since it is generally present in proportionately higher quantities and has long been known to be a potent carcinogenic agent.
In an effort to lower the polycyclic aromatic hydrocarbon content of tobacco smoke, a host of various treatments of tobacco materials have been proposed in the art. For example, the addition of nitrates and nitrites to tobacco has been previously described in patents and in published literature. For example, French Patent No. 1,180,320 teaches the addition of nitrites to tobacco and cigarette paper to reduce the polycyclic aromatic hydrocarbon yield. U.S. Pat. No. 3,121,433 describes the addition of potassium nitrate to reconstituted tobacco sheet to improve its burning characteristics. U.S. Pat. No. 3,180,458 teaches the addition of potassium and sodium nitrate to tobacco and it discloses a reduction of cigarette tar yield which is caused by the increased burn rate of the cigarette. Huntley and Bergun (Analyst, volume 85, p. 727-730 (1960)) describe the addition of copper and potassium nitrates to reduce the yield of 3,4-benzopyrene from the cigarette smoke.
The treatment of tobacco compositions with platinum group metals such as platinum, palladium, rhodium, osmium, iridium or ruthenium to lower the concentration of active carcinogens such as benzopyrene in tobacco smoke is disclosed in British Patent No. 841,074.
Another approach suggested to reduce polycyclic aromatic compounds involves the use of zeolite molecular sieve compositions. For example, U.S. Pat. No. 3,292,636 discloses tobacco preparations in combination with crystalline zeolite molecular sieves such as L, X, Y, or synthetic mordanite types or naturally occuring fraujasite materials, which sieves may contain any metal containing a vapor pressure below one atmosphere at 1000° C. and possessing catalytic activity for organic conversion. U.S. Pat. No. 3,572,348 also relates to a smoking preparation comprised of a zeolite material which effects a decrease in the amount of polycyclic aromatic compounds produced from the combustion of tobacco. This zeolite material is of the Y-type structure and is at least partially exchanged with zinc ion or containing metalic palladium or at least partially exchanged with zinc ions and containing metallic palladium, or is partially polyvalent zinc cation exchanged and partially decatonized and contains metallic palladium. U.S. Pat. No. 3,703,901 also discloses a Y-type zeolite structure at least partially exchanged with zinc ions and containing platinum or silver for reducing the amount of polycyclic aromatic compounds in tobacco smoke.
The use of cerium sulfate together with compounds of titanium, zirconium and tin to remove nicotine from tobacco smoke has been proposed in German Patent No. 640,193.
As indicated by the above prior art, a concerted effort has been expended to reduce deliterious substances in tobacco smoke. However, these treatments suffer various shortcomings and have not had a degree of commercial success. Therefore, any method or improvement for decreasing substantial amounts of polynuclear aromatic hydrocarbons especially benzo(a) pyrene in tobacco, which would produce a commercially feasible product, would appear to be highly desirable and beneficial. Ideally a method which can be applied or used in a continuous process compatible with existing manufacturing techniques thereby adding no appreciable cost to the production expense of the tobacco product is most desirable. Furthermore, the novel tobacco product produced therefrom should not adversely affect the taste or aroma of the tobacco smoke. The present invention fulfills all these aforementioned goals.
SUMMARY OF THE INVENTION
The present invention relates to a novel tobacco smoking composition which comprises tobacco and an active agent comprising a mixture of auric oxide, silver nitrate, or sulfate platinum tetrachloride and a cerium (III) salts selected from the group of carbonate, sulfate and nitrate in an effective amount to reduce a substantial percentage of polycyclic aromatic hydrocarbons especially benzo (a) pyrene, nicotine and raw condensate content in the tobacco smoke and the process for making this novel smoking composition.
While the present invention has applicability to the treatment of any gas stream containing carcinogenic hydrocarbons, it will be described most particularly with respect to tobacco smoke.
It is an object of the present invention to provide a chemical additive for tobacco which will substantially eliminate certain deliterious substances normally found in the products of combustion when the tobacco is burned.
Another object of this invention is to disclose a tobacco mixture containing a chemically active agent for reducing benzo(a)pyrene and other deliterious materials produced when the tobacco is burned.
Still another object of this invention is to disclose a non-toxic chemical additive for tobacco which will decrease the amount of carcinogenic components to be found in the tars of the smoked tobacco, yet will not produce toxic materials themselves while reducing the harmful hydrocarbons and the combustion products of the tobacco.
Still another object of this invention is to disclose a cigarette which produces less benzo(a)pyrene and less raw condensate when the tobacco is smoked.
A further object is to provide a process of treating tobacco with a chemical active agent for decreasing the amount of certain deliterious products produced when the tobacco is burned.
A still further object of this invention is to disclose a process for producing a cigarette which when smoked produces a minimum of benzo(a)pyrene, raw condensate and nicotine.
These and further objects and advantages of this invention will be more apparent upon reference to the accompanying detailed description, specific examples and claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention it has been found that a certain combination of chemical compositions when added to tobacco substantially reduces a portion or percentage of benzo(a)pyrene and the raw condensate which are produced when the tobacco is burned in a cigarette. The discovery that the unique combination of these chemical substances would reduce the benzo(a)pyrene and the raw condensate content was quite unexpected since various compounds that are similar have been ineffective for this purpose.
The chemical active agents contemplated by this invention can be incorporated into the tobacco in any desirable manner. For example, solutions of the chemically active agent in a suitable solvent, such as water, can be applied to the tobacco by spraying, soaking, sprinkling or the like after which the solvent is driven off as a vapor leaving the additive thoroughly incorporated with the tobacco. The active agent can also be applied as a finally-divided material to a dusting, shaking or dispensing medium of any suitable type which will uniformly disperse the additive over the tobacco. The incorporation of the active agent may take place at any time prior to the final packaging of the tobacco product. In the case of cigarette tobacco, it may be incorporated before or after blending of the various tobaccos if, in fact, blended tobacco is employed and the additive may be applied to one or all of the blend constituents. The mixture of chemical substances should be well-dispersed through the tobacco so that it will be uniformly effective during the entire smoke.
The amount of active agent in the final product contemplated by this invention to effectively reduce the benzo(a)pyrene and raw condensate is quite small. Generally, desirable reduction of these deliterious substances can be obtained if the active agent mixture is incorporated into the final tobacco product in amounts between about 0.1 and 10 weight percent, preferably 0.5 to 5 weight percent and most preferably 1 to 5 weight percent in reference to the total weight of the tobacco.
The active chemical agent additive is a mixture comprising:
(a) 75-99 weight percent of a cerium III salt selected from carbonates, nitrates and sulfate;
(b) 0.5-20 weight percent of silver nitrate or sulfate;
(c) 0.1-10 weight percent auric oxide; and
(d) 0.05-5.0 weight percent platinum tetrachloride.
Preferred ranges: cerium (III) salt 85-99 weight percent; silver nitrate or sulfate, 0.5-5 weight percent; auric oxide, 0.5-5 weight percent and 0.1-1.0, platinum tetrachloride. Most preferred ranges: cerium (III) salt; 95-99, silver nitrate or sulfate, 1-5 weight percent; auric oxide, 0.5-1.5 weight percent and platinum tetrachloride, 0.1-0.5 weight percent. All the percentages are based on the dry tobacco containing the conventional amount humidity.
Preparation of Tobacco Samples
The experiments were carried out with tobacco from two brands of commercial cigarettes.
The commercial cigarettes were carefully ripped by a special machine and the tobacco was collected and stored at a temperature of +4° C. Packed fine-cut tobacco, pipe and cigar tobacco and tobacco leaves were not used. Tobacco in commercial cigarettes is more homogeneous than the other types of tobacco mentioned and thus the quality of the experimental cigarettes can be assured by comparing them with original commercial cigarettes.
A solution of the chemically active agent mixture was prepared by dissolving 100 grams of cerium (III) nitrate, 073 grams auric oxide, 2 grams silver nitrate and 0.35 grams of palladium tetrachloride in 5 liters of water. This volume of chemical active agent is sufficient to treat 16 kilograms of tobacco.
The treatment substances were sprayed on the tobacco in a drum mixer. When the spraying was completed, mixing was continued for about two minutes before the tobacco was removed from the drum. The treated tobacco (46 weight percent water) was placed on a drying hurdle and for two days was dried with repeated turning to a moisture content conventionally used in cigarette making (11 to 13 weight percent water). After this drying step the tobacco was filled into plastic bags and stored for one or two days to obtain uniform distribution of the residual moisture.
The tobacco not treated with the chemical active agent of the present invention was subjected to the same treatment except that distilled water was used instead of the treatment solution.
Cigarette Making
Cigarettes were produced from the treated and untreated tobacco batches. To ensure that there would be a minimal or no influence on the test results by the cigarette paper and adhesive, all samples were manufactured using Pela 40MC cigarette paper (Schoeller and Hoesch) and an adhesive marketed as Dextraco11DH 4030 (Sichel Werke GmbH, Hannover, Germany) to glue the cigarette paper together. Each manufactured cigarette was then checked for size, i.e. diameter, puff resistance and weight. The diameter of the cigarettes was 8.0 plus or minus 0.1 millimeter as measured by a ring gauge for non-destructive measurement of circumference and diameter of the sample cigarettes. The puff resistance was determined separately for each cigarette. Emperical values of puff resistance were obtained from measurements of corresponding commercial cigarettes and was measured as the pressure drop occuring while air is being sucked through the cigarette using a puff volume of 35 mls at an air flow velocity of 17.5 centimeters cubed per second at a temperature of 20° C. and a pressure of 1.01 (760 millimeters). These measurements reflect on the packing density of the tobacco. Accordingly, values between 3 and 4 millimeter water gauge were acceptable since they corresponded to values obtained with commercial cigarettes.
The cigarettes were then machine smoked in accordance with DIN Specification 10240, using the RM 20/CS smoking machine manufactured by Borgwald, Hamburg, Germany. The puff duration was two seconds, the puff volume 35 milliliters and the puffing rate one puff in 60 seconds. The puff profile was bell-shaped, and the butt length was adjusted to 23 millimeters. In addition, the number of puffs per cigarette was measured in order to obtain information about the burning properties of the cigarette.
Prior to testing the experimental cigarettes were stored at a temperature of 22° C. and 60% relative humidity for a period of 72 hours.
Analysis of Tobacco Smoke
Smoke condensate collection and subsequent analysis were carried out according to DIN Specification 10240, parts 1 to 3, i.e., conditioned cigarettes were machine smoked and the condensate collected on conditioned glass -fiber filters of known weight. The condensate volumes were determined by comparing the weights of the filters before and after machine smoking. The filters bearing the raw condensate were left in a desicator at a controlled atmosphere (22° C.±1° C.) until constant weight was achieved. This generally took 72 hours. The dry condensate content percent weight was then calculated from the total number of cigarettes smoked and the weight difference.
The nicotine content of the tobacco smoke condensate was dissolved in methanol and determined in accordance with DIN Specification 12242. After a two-stage water vapor distillation, the nicotine content of the distillate was measured spectrophotometrically. The analytical procedure for benzo(a)pyrene involves about 300 to 400 milligrams of freshly collected tobacco smoke condensate taken from the glass-fiber filters or the electrostatic smoke trap and poured over a cellulose acetate column together with 20 to 30 ml ethyl alcohol. cellulose acetate column is prepared by mixing 30 g cellulose powder with ethyl alcohol to give a thin-bodied homogeneous paste which is filled into a chromatographic tube sealed with glass wadding. After the powder has settled (filling height about 40 cm) and the ethyl alcohol has been drained, the column is eluted with 100 ml benzene at 3 bar (nitrogen). Subsequently the benzene is driven out again by the residual ethyl alcohol. A column prepared in this way can be used for a large number of experiments. When the sample has soaked into the column, the column is eluted with ethyl alcohol at 3 bar (nitrogen). The eluate (300 ml) is discarded. Eluation is repeated with benzene with the irregular penetration front clearly visible. The eluate (120 ml), has a light-yellow color, is then concentrated to about 2 ml in a tapered flask at vacuum and at a maximum temperature of 40° C. To remove the residual benzene, the sample is mixed with 3 ml isooctane and subsequently concentrated to about 0.5 ml by flashing with nitrogen at room temperature. This sample is then carefully poured over a prepared silica gel column together with 5 ml of the eluant. A silica gel column is prepared in the following manner: a relatively large quantity of silica gel is placed on a glass frit and washed with concentrated hydrochloric acid until, using rhodanide, iron is no longer detected in the filtrate. The gel is then washed with water to remove the chloride and rewashed with methanol. After removal of the methanol in the rotation evaporator, the silica gel is left to dry at 140° C. for 12 hours. 20 g of the gel thus prepared is mixed with methanol and filled into a chromatographic tube sealed with glass wadding (filling height about 20 cm). The methanol is drained and driven out completely with benzene, which in turn is driven out by the eluant proper (cyclohexane/benzene at a ratio of 195:5). A silica gel column can be used only once. The column is then eluted with cyclohexane/benzene at a ratio of 195:5. With a ultraviolet hand lamp (excitation wavelength 365 nm) the benzo(a)pyrene is clearly visible as a blue-violet fluorescent zone. The first 45 to 50 ml of the eluate is discarded and the next fraction containing the benzo(a)pyrene has a volume of 60 ml and is colorless. The fraction containing the benzo(a)pyrene is carefully concentrated to 5 or 10 milliliters and subsequently its fluorescence spectrum in the region of 340 to 500 nm is recorded (excitation wavelength 298 nm). The spectrum shows all the important characteristics of benzo(a)pyrene (maximus at 405, 430 and 455 nm; shoulder at 410 nm). In addition, it shows a slight background and often has another maximum at 367 nm, which is possibly due to an additional aromatic substance. The maximum at 405 nm is used for quantitative evaluation.
The tobaccos used in the above described testing procedures were a German commercial blend and an American commercial blend. Samples were treated with a 2.05 weight percent solution of the unique tobacco additive of the present invention. The following data presented in TABLES I and II clearly show the unexpected and nonobvious ability of the chemical active agent in removing substantial amounts of undesirable components in tobacco smoke. The data represents an average of at least 200 determinations. Statistical evaluation of the test values has been carried out in accordance with DIN 1240.
TABLE I______________________________________ Weight Benzo per Raw (a) pyr- Nico- Cigar-GERMAN condensate Number ene tine etteBLEND (mg) of puffs (ng) (mg) (g)______________________________________UNTREATED 31.33 8.75 27.2 1.43 0.98THISINVENTION 26.4 9.78 22.9 1.10 1.00Δ% -15.7 +11.8 -15.8 -23.3 --______________________________________
The changes in raw condensate, number of puffs, benzo(a)pyrene and nicotine are highly significant.
TABLE II______________________________________ Weight Benzo per Raw (a) pyr- Nico- Cigar-AMERICAN condensate Number ene tine etteBLEND (mg) of puffs (ng) (mg) (g)______________________________________UNTREATED 25.7 7.86 18.5 1.328 0.94THISINVENTION 24.0 7.49 14.9 1.145 0.94Δ% -6.6 -4.7 -19.5 -13.8______________________________________
The changes in raw condensate, number of puffs, benzo(a)pyrene and nicotine are highly significant.
While the above data are specific to benzo(a)pyrene, it also reflects a reduction of the other polycyclic aromatic hydrocarbons since the benzo(a)pyrene as mentioned hereinbefore is present in larger quantities than the other polycyclic aromatic components.
Other conventional tobacco additive materials such as flavorants and humectants, in addition to those described above may be used in the practice of the present invention without deviating from the scope thereof.
While the invention has been described in detail with particular reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.
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A novel smoking composition is provided by treating tobacco with an active agent comprising a mixture of auric oxide, silver nitrate or sulfate, platinum tetrachloride and cerium (III) salts selected from the group of carbonates, sulfates and nitrates in an effective amount to reduce a substantial percentage of polycyclic aromatic hydrocarbons, nicotine and raw condensate in the tobacco smoke.
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CONTRACTUAL ORIGIN OF THE INVENTION
The invention described herein was made in the course of, or under, a contract with the UNITED STATES ENERGY RESEARCH AND DEVELOPMENT ADMINISTRATION.
BACKGROUND OF THE INVENTION
The invention is directed to a machine tool system for producing optical quality surface finishes on large spherical, aspherical, flat, and irregular surfaces.
Conventional fine machining systems often resemble "T" bed turning and boring machines. Such machines often have stacked slides and may have a machine spindle mounted on one slide and a cutting tool on another slide, making a 90° angle with the first slide. The slides are usually quite massive and require ball-screw mechanisms for accurate movement. It is also common practice to employ caged roller mechanisms between sliding members and way surfaces to reduce friction; these devices create mechanical noise which is reflected in the surface of the workpiece. These disadvantages are avoided by the omega-X micromachining tool system.
Several additional problems arise when a surface must be finished to an optical quality, i.e., 3 nanometers RMS (3 × 10 -9 meter). First, the cutting tool is moved directly toward or away from the workpiece; because of the orthogonal axes and relatively large pulse increments from the pulsed motor system commanding movement of the carriage, the movements toward or away from the workpiece are large compared to the accuracy desired. Second, the inertia of the moving carriage is large; it tends to cause overtravel because the inertia is difficult to overcome before the carriage has exceeded the commanded distance. Third, the ball-screw mechanism used to move the carriage is not "stiff" enough to control the carriage movement; the mechanism is subject to backlash and dimensional changes due to stress imposed by loads. Fourth, unwanted motion can be transmitted to the workpiece from the driver through the spindle which further disturbs the desired spatial relationship of the tool to the workpiece. These errors are, of course, in addition to errors in the shape and dimensions of the tool bit employed, and errors incurred in establishing a precisely known position of the tool bit nose in relation to the workpiece.
SUMMARY OF THE INVENTION
The invention is directed to a micromachining tool system which employs a new axis of motion, new machine calibration instruments and a thermally stabilized spindle for mounting and rotating a workpiece. The micromachining tool includes means for rotating a workpiece, a tool bar carrying a tool bit at one end for cutting the workpiece, a first slide for moving the tool bar in a direction perpendicular to the plane of the workpiece, and a second slide mounted on the first slide aligned in a direction parallel to the plane of the workpiece. The second slide includes means for swinging the tool bar about an axis located near its end remote from the tool bit and perpendicular to the axes of the first and second slides, and means for moving this perpendicular axis along an arc surrounding the perpendicular axis at the same time the tool bar is swinging on said perpendicular axis.
Concerning the axes of motion, the micromachining tool is capable of movement in conventional X and Z axes, the X axis being defined as usually horizontal and at a right angle to the Z axis which is perpendicular to the plane of the workpiece and coaxial with the spindle on which the workpiece is mounted. For normal machining operations, however, the Z axis movement is not employed. Because of the lesser importance of movement along a Z-axis slideway, the Z axis has been located on the spindle centerline to facilitate the description of the micromachining tool, rather than parallel to it, as would be dictated by generally accepted nomenclature for machine tools. Instead, one end of a tool bar is pivotally linked to eccentric adjustment guides on an eccentric mechanism; rotation of the eccentric moves the tool bar pivot through an arc of as much as 180 degrees on a radius (centered on the Y axis which passes through the center of the eccentric mechanism at a right angle to the X-Z plane) whose length is determined by the amount of offset between upper and lower eccentric adjustment guides. Therefore, for a given rotation of the eccentric mechanism, motion of the tool bar along the Z axis may be varied depending upon where the pivot is located on the arc of the described circle. This angular movement of the tool bar pivot point is measured by an angle omega formed by the Z axis and the radius on which the pivot point lies. It is the first of two machining motions. At the same time, the other end of the tool bar which mounts the tool bit slides in a linear air bearing pivotally attached to a pivot bearing mounted on a cross slide and travelling along the X axis; this is the second of two machining motions. Note that errors in movement along the X axis due to inaccuracies in the lead screw mechanism driving the X axis will have a minimum effect on the accuracy of the machined contour since the X axis lies in a plane parallel to the plane of the workpiece and at a right angle to the Z axis. Furthermore, the linear air bearing has an averaging effect on the tool bar since the air bearing is long in relation to the errors in the machined surfaces of the tool bar itself; this averaging effect reduces erroneous movements of the tool bar in X, Y and Z directions. Furthermore, errors in the X axis lead screw mechanism which would cause erroneous movement of the tool bit along the Z axis cannot be transmitted to the tool bit because of the free movement of the tool bar with respect to the linear air bearing; consequently, the only errors in the X axis that can cause errors in the workpiece contour are lead errors in the actuating screw itself which cause errors in the X direction. For this reason, the X axis servodrive and lead screw mechanism are very accurately calibrated by a laser interferometer. Motion in the omega and X axes may be combined in order to move the cutting tool along a desired contour, maintaining very high accuracy and avoiding serious problems inherent in the prior art. The micromachining tool system is controlled by a dedicated computer which has previously been supplied with the precise position of the tool bit nose, the shape of the tool bit nose and the desired contour to be produced on the workpiece. Necessary tool bit motions in the omega and X axes are calculated by a mathematical program which relates omega and X coordinates to coordinates describing the position of a point on the surface of the workpiece and supplied to the dedicated computer.
Because desired accuracy is less than 100 nm contour error and 0.8 nm RMS surface finish and because the incremental movement of the tool in the Z axis may be varied between 0 to 4.4 nm, it is necessary to use new machine tool calibration techniques in order to accurately determine the position of the tool nose. By way of comparison of various surface finishing techniques, the following table is presented:
______________________________________Method Finish Accuracy (nm, RMS)______________________________________Fine machining 800Fine grinding 100Lapping 12-25Omega-X micromachining 0.8______________________________________
First, with regard to initial calibration, the spindle is aligned coaxially with the Z axis. Next, the tool bar is aligned parallel to the Z axis. Then, the pivot bearing position on the X axis is calibrated by a laser interferometer; each step of the lead screw mechanism as indicated by master and secondary encoders in the X-axis servodrive is measured by the interferometer and relayed to the dedicated computer. Then, the distance between the Y axis of the eccentric mechanism represented by the center of an eccentric reference ball located on the Y and Z axes and the parallel pivot axis of the pivot bearing mounted on the X slide must be determined. To accomplish this, the eccentric reference ball and a pivot reference ball are located on the X and Z axes horizontally and vertically on the Y axis and pivot axis, respectively. The distance between the centers of the two balls is then determined by a pivot axis calibrating device which is a length standard with a linear variable differential transformer (LVDT) mounted at one end. The computer may then be instructed with this distance so that movement of the X-axis slide may be related to movement of the tool itself. The eccentric reference ball and pivot reference ball are located in X and Y directions by sweeping in the surface of each reference ball by an indicator mounted on an extension bracket attached to the spindle. The accuracy of location of each ball is ±250 nm. The position of the eccentric mechanism through the full range of the omega axis is angularly calibrated by laser interferometer and stored in the computer.
Next, a tool bar length standard which consists of a bar of known length with a LVDT mounted at one end is inserted through the tool bar which, for this reason, is hollow. The purpose of the length standard is to establish a reference point in space, 1 meter from the center of the eccentric reference ball, which is on the Z axis. The tool bar in this position is also aligned concentrically with the Z axis. The point in space is then transferred to a tool calibration fixture temporarily installed on the end of the tool bar which contains tool height, tool offset, and tool bar length LVDT's. The position of the reference point in X and Y directions is determined from a tool height and offset calibration insert. To preserve the measurement, the calibration fixture and its LVDT's are used to transfer their readings to a calibration fixture mastering station possessing an anvil which represents the tool bit. Initial calibration accuracy is ±25 nm. Once this is accomplished, the mastering station is used as a reference for setup calibration until such time as the entire calibration must be repeated.
Eccentric offset is measured by a laser interferometer.
Once the tool bit has been installed and located at the reference point by the calibration fixture, its nose contour is gaged by a tool gage which is composed of a glass plate containing two electrical contacts and supporting a steel ball resting against the contacts. As the tool bit is moved against the steel ball, the very slight contact pressure causes an extremely small movement of the steel ball which breaks the electrical circuit between the two electrical contacts. The contour information is supplied to the dedicated computer controlling the micromachining tool so that the computer knows not only the position of the tool bit to an accuracy of ±25 nm but also the contour of the tool bit nose to an accuracy of ±25 nm.
The micromachining tool system employs an air-bearing thermally-stabilized spindle to rotate the workpiece. The spindle is driven through a torque-smoothing pulley and vibrationless rotary coupling which minimize transmission of undesired motion to the spindle and workpiece from the motor rotating the spindle. The spindle has a gravity-fed oil cooling system to temperature-stabilize the air-bearing spindle and prevent changes in location of the workpiece due to thermal growth caused by heating of the spindle.
The entire micromachining tool system, except for its driving motor, is air-mounted, oil-bathed, and contained within a sound-dampened enclosure and room.
A workpiece gage similar to the tool gage may be mounted on the end of the tool bar to gage the contour of the workpiece in a fashion similar to that by which the tool bit nose contour itself is gaged. Gaging the workpiece while still on the machine avoids the possibility that deformation after removal could be construed as machine caused error.
It is an object of the invention to produce spherical, aspherical, and irregular surfaces up to 1 meter in diameter with contour errors no greater than 100 nm and surface finishes less than 0.8 RMS.
It is another object of the invention to provide variable increments of movement along the Z axis of the micromachining tool.
It is another object of the invention to significantly reduce the mass pulsed directly toward the workpiece.
It is another object of the invention to accomplish tool setting and calibration at the height of the Z axis to reduce as far as possible Abbe offset error.
It is another object of the invention to reduce and eliminate as far as possible mechanical backlash in the omega axis and X axis of motion.
It is another object of the invention to provide on-machine gaging of tool bit nose and workpiece contours.
It is another object of the invention to provide workpiece rotational accuracy of 25 nm total indicated reading (TIR) maximum.
It is another object of the invention to provide a thermally-stabilized workpiece spindle which receives torque through a torque-smoothing pulley and vibrationless rotary coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an omega-X micromachining tool with its enclosure partially broken away.
FIG. 2 is a schematic view of the axes of motion of the micromachining tool.
FIG. 3 is a view in a Y-Z plane, partially in section, of an eccentric mechanism and tool bar of the micromachining tool along line 3--3 in FIG. 4.
FIG. 4 is a sectional view in an X-Y plane of the eccentric mechanism along line 4--4 of FIG. 3.
FIG. 5 is a plan view in an X-Z plane of the eccentric mechanism and tool bar along line 5--5 of FIG. 3.
FIG. 6 is a detail view in an X-Z plane, partially in section, of eccentric adjustment guides in the eccentric mechanism along line 6--6 of FIG. 3.
FIG. 7 is a sectional view in an X-Z plane of an eccentric rotating mechanism in the eccentric mechanism along line 7--7 of FIG. 3.
FIG. 8 is a detail sectional view of a pivot link between the rotary table and plate on the lower eccentric adjustment guide along line 8--8 of FIG. 7.
FIG. 9 is a detail view in a Y-Z plane of a shimming clamp on a tool bar end bearing plate along line 9--9 of FIG. 5.
FIG. 10 is a sectional view in a Y-Z plane of a tool bar, linear air bearing and pivot bearing along line 10--10 of FIG. 11.
FIG. 11 is a sectional view in an X-Y plane of the linear air bearing along line 11--11 of FIG. 10, with the tool bar removed.
FIG. 12 is a sectional view in an X-Z plane of the pivot bearing along line 12--12 of FIG. 10.
FIG. 13 is a sectional view in a Y-Z plane of a tool head and tool bar along line 13--13 of FIG. 14.
FIG. 14 is a view in an X-Y plane of the tool head and tool bar along line 14--14 of FIG. 13.
FIG. 14A is a detail sectional view of a friction lock in the tool head.
FIG. 15 is a sectional view in an X-Y plane of the tool head along line 15--15 of FIG. 13.
FIG. 16 is a sectional view in a Y-Z plane of a head piece with removable parts removed along line 16--16 of FIG. 14.
FIG. 17 is a view in a Y-Z plane, partially in section, of a pivot axis calibrating device mounted on an eccentric reference ball and a pivot reference ball.
FIG. 18 is a view in an X-Y plane of the pivot axis calibrating device along line 18--18 of FIG. 17.
FIG. 19 is a sectional view in a Y-Z plane of a tool bar length standard mounted in the tool bar and on the eccentric reference ball.
FIG. 20 is a view in an X-Y plane, partially in section, of the tool bar length standard and tool head along line 20--20 of FIG. 19.
FIG. 21 is a sectional view in an X-Y plane of the tool bar length standard along line 21--21 of FIG. 19.
FIG. 22 is a view in an X-Y plane of the tool bar length standard along line 22--22 of FIG. 19.
FIG. 23 is a view in a Y-Z plane of a tool calibration and offset insert.
FIG. 24 is a view in an X-Y plane, partially broken away, of the tool calibration and offset insert.
FIG. 25 is a view in an X-Y plane of the tool calibration and offset insert.
FIG. 26 is a view, partially in section, in a Y-Z plane of a tool calibration fixture mounted on the tool head over a tool bit, along line 26--26 of FIG. 27.
FIG. 27 is a view, partially in section, in an X-Z plane of the tool calibration fixture mounted on the tool head, along line 27--27 of FIG. 26.
FIG. 28 is a detail sectional view in an X-Y plane of an LVDT clamp along line 28--28 of FIG. 26.
FIG. 29 is a sectional view in a Y-Z plane of a mastering station along line 29--29 of FIG. 31.
FIG. 30 is a view in an X-Z plane, partially in section, of the mastering station along line 30--30 of FIG. 29.
FIG. 31 is a view in an X-Y plane of the mastering station along line 31--31 of FIG. 29.
FIG. 32 is a sectional view in a Y-Z plane of a main air bearing spindle.
FIG. 33 is a sectional view in an X-Y plane of the main air bearing spindle along line 33--33 of FIG. 32.
FIG. 34 is a detail view, partially broken away, of a spherical journal bearing from the main air bearing spindle.
FIG. 35 is a view, partially in section, in an X-Y plane of a tool gage and gage arm.
FIG. 36 is a sectional view in a Y-Z plane of the tool gage along line 36--36 of FIG. 35.
FIG. 37 is a view in an X-Z plane, partially in section, of a workpiece gage mounted on the tool bar.
FIG. 38 is a sectional view in a Y-Z plane of the workpiece gage.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The omega-X micromachining tool system is comprised as shown in FIG. 1 of a number of major components. Each major component of the tool system is shown in detail in succeeding figures. Calibration instruments are not shown in FIG. 1. Some of the components are conventional and may be found in many machine tools other than the omega-X system. In the description, reference numbers identify not only parts, but generally also identify the figure (a) in which the part is best shown, and (b) in connection with which the part is originally discussed. Also, by using FIG. 1, the figures showing any component in greater detail may be readily ascertained by referring to the reference number. In a three-digit reference number, the first digit denotes the figure; in a four-digit reference number, the first two digits denote the figure; e.g., part 1000 is shown in FIG. 10; the discussion accompanying FIG. 10 is the comprehensive description of this part. Constituents of part 1000 are given numbers 1002, 1004, etc.
FIG. 1 displays a machine base 110 supported by four air suspension mounts 112. The base 110 provides a rigid structure of considerable mass and high dimensional stability on which to mount the remaining machine components. Machine base 110 is aged and annealed steel; many of the other components are constructed of cast iron, one of the several suitable specifications being ASTM-A48-T60, known commercially as Meehanite, grade GM-60. Air suspension mounts 112 are used to maintain the machine in an exactly level attitude despite machine movements and changes in weight distribution by means of three fluidic level controls 114 two of which are mounted on the air suspension mounts 112 away from the drive motor and the third (not shown) at the front of the machine base 110. The entire micromachining tool is located within a room which has sound-dampening material on its walls to provide acoustic isolation. On top of the machine base 110 Z axis slideways 116 are mounted; the slideways provide support to a first slide, denoted as Z axis slide 118. A Z axis slewing motor 120 drives the Z slide 118 through a conventional ball-screw mechanism (not shown). Position of the Z slide 118 is indicated by a Z axis encoder 122. Note that the Z axis of the micromachining tool is not provided with a servodrive since Z axis motion is only used for rough positioning of the tool; in fact, the Z axis is locked during all machining movements. The position of the Z slide 118 may be determined to an accuracy of ±1250 nm by means of the Z axis encoder 122.
Atop the Z axis slide 118 are mounted several of the components which contribute to the great accuracy of the omega-X micromachining tool system. The first of these is an eccentric mechanism 300 which provides support and rotation of a hollow, elongated parallelepiped tool bar 500 in the omega axis. With no offset, as shown in FIG. 1, between upper and lower eccentric adjustment guides 401 and 403 which slide with respect to each other, the center of an eccentric reference ball 400 is on the Y axis, which here coincides with the vertical axis of the eccentric mechanism 300. The amount of offset of the ball 400 from the Y axis is determined by the relative displacement of the upper and lower eccentric adjustment guides 401 and 403. An omega axis servodrive 144 rotates the eccentric mechanism via a rotary table 301. The rotary table 301 is contained within the eccentric mechanism 300. The angular position of the rotary table 300 is determined by omega axis master and secondary encoders 148 and 150 which, in turn, supply this information to a dedicated computer (not shown) which controls the micromachining tool. The rotary table 301 is "Ultra-Precise" model manufactured by the Moore Special Tool Company and is accurate to ±2 seconds of arc; any rotary table may be used as long as the required accuracy standard is met. Trueness of rotation is 250 nm TIR.
Next, a tool bar end bearing plate 501 is pivotally attached to the eccentric mechanism 300 through heavily preloaded angular-contact ball bearings 314, shown in FIG. 3. A tool bar 500 is fixed at one end to the tool bar end bearing plate 501 by a tool bar clamp 316 and shimming clamp 900 (not shown in FIG. 1). The tool bar 500 slides through and is supported by a linear air bearing 1000 which is pivotally supported by a pivot bearing 1100. The pivot bearing 1100 is attached to a second slide, denoted as X axis slide 162 which, like the eccentric mechanism 300, is mounted on X axis slideways 163 on the Z axis slide 118. Motion of the X axis slide 162 is controlled by the X axis servodrive 164 which contains a lead screw mechanism (not shown). Position of the X axis slide 162 is determined by the X axis master and secondary encoders 166 and 168 which, in turn, relay the position information to the dedicated computer. Each increment of motion of the lead screw in the servodrive 164 represents about 1 nm in the X axis. A tool head 1300 containing a tool bit 200 (not visible in FIG. 1) is mounted in the other end of the tool bar 500.
Mounted on a raised section 170 of the machine base 110 is a main air-bearing spindle 3200 which supports and rotates the workpiece 174. The spindle 3200 is rotated by a spindle drive motor 176 through a torque-smoothing pulley 177, a belt drive 182, and a vibrationless rotary coupling 178. Note that the spindle drive motor 176 is mounted on its own motor base 180 and that the motor base 180 is completely separate from the machine base 110. This feature, along with the pulley 177, the coupling 178, and the belt drive 182 connecting the motor 176 and driving side of coupling 178, all contribute to a reduction of unwanted motion in workpiece 174, thus increasing the accuracy of the omega-X micromachining tool system.
At one end of the main air-bearing spindle 3200 is mounted a funnel 184 for supplying coolant by gravity to the air-bearing spindle 3200 in order to accomplish thermal stabilization of the air-bearing spindle. Another funnel 185 is mounted to a hole 503 in an end of tool bar 500 nearer the eccentric mechanism 300; funnel 185 conducts oil coolant by gravity into tool bar 500.
Lastly, a tool gage 3500 mounted on gage arm 3502 may be rotated into position by a linear and rotary bearing quill 188 in order to determine the exact nose contour of the tool bit 200 mounted in the tool bar 500. The contour information is relayed to a dedicated computer. This further increases the accuracy of the omega-X micromachining tool system by enabling the dedicated computer to account for inaccuracies of as little as ±25 nm in the shape of the nose of the tool bit 200.
The entire micromachining tool system except for the spindle drive motor 176, motor base 180 and belt drive 182, is enclosed by a sound-dampened sheet metal housing 109 which anchors to a base pan 111. A cooling oil network (not shown) on the inside of the housing distributes oil over the micromachining tool system to prevent temperature variations throughout its structure; oil is collected by the base pan 111. The sound dampening is necessary since even the sound of a human voice or a draft of air is capable of producing distortions in the workpiece 174 which are larger than the desired accuracy of system. For example, air currents generated by door movement have caused the micromachining tool, which weighs about seven metric tons, to move through an arc of 5 to 7 seconds.
FIG. 2 describes the machining motions of the omega-X micromachining tool system. The X axis as displayed by FIG. 2 is parallel to the plane of rotation of the workpiece 174 and usually horizontal. Because the Z-axis slide 118 is stationary during actual machining movements, the Z axis is at a right angle to the X axis and coaxial with, rather than merely parallel to, the center of the main spindle 3200 and workpiece 174. As can be seen, motion in the X axis is produced by the X axis slide 162 being moved along the X axis by the X axis servodrive 164 shown in FIG. 1 so that the linear air bearing 1000, linked to the pivot bearing 1100 which moves with the X axis slide 162, also moves on the X axis, thus swinging the tool bar 500 about a pivot point centered at the eccentric reference ball 400. Consequently, as the linear air bearing 1000 is guiding the tool bar 500 through its arc, the air bearing 1000 is also rotating and sliding along the tool bar 500 toward the eccentric reference ball 400 and then away from it, assuming that a tool bit 200 mounted on the tool head 1300 and tool bar 500 is moving as shown by the second tool bar position, shown in phantom in FIG. 2.
The omega axis is the circular arc described by the eccentric reference ball 400 as it is rotated about the Y axis by the eccentric mechanism 300. In FIG. 2, the omega axis consists of a 180 degree arc of a circle on the side of the eccentric mechanism 300 away from the workpiece 174. (Arcs as great as about 300 degrees are possible). The radius of the arc is varied by offsetting the eccentric reference ball 400 (and therefore the center of the Y axis) from the Y axis by means of the upper and lower eccentric adjustment guides 401 and 403 shown in FIGS. 1 and 6. Of course, if the eccentric reference ball 400 is on the Y axis, there will be no movement of the pivot point of the tool bar 500 regardless of rotation of the eccentric mechanism 300 and the tool bit 200 will merely swing in a pure circular arc centered on the Y axis. Note that, assuming offset is not zero, identical increments of rotation of the eccentric mechanism 300 give varying increments of motion of the eccentric reference ball 400 in the Z axis; this means that the amount of movement of the tool bit 200 toward and away from the workpiece 174 is controlled very precisely. The displacement in the omega axis is measured by the angle ω formed between the Z axis and the radius on which the pivot point, represented by reference ball 400, lies. In the present embodiment, it is anticipated that this increment will vary from 0 to 4.4 nm. Presently available systems employ an increment of about 25 nm as the smallest increment of motion. The dedicated computer is programmed by conventional mathematical methods to calculate the necessary movements in both X and omega axes, given desired contour of the workpiece 174 and the accuracy required, assuming that the micromachining tool system has been previously calibrated.
The preceding description of the micromachining tool system and its axes of machining movement give the reader a general concept of the function of each major component and its interrelationship with other components. Next will follow a detailed description of each of the major components of the omega-X micromachining tool system.
The first such component to be described in detail is the eccentric mechanism 300 which is displayed in greater detail in FIGS. 3 through 7. The purposes of the eccentric mechanism 300 as shown in FIG. 3 are several. First, it must provide a support for one end of tool bar 500. Second, it must provide rotation in the omega axis. Third, it must be able to accomplish the variable offset required to determine the radius of the omega axis. Fourth, it must reduce mechanical backlash or eliminate it wherever possible in order to provide the most precise control of movements of the tool bit 200.
The rotary table 301 of the eccentric mechanism 300 is attached by bolts 302 to the inside of the eccentric mechanism housing 304 which supports the lower eccentric adjustment guide 403 and through it, the remainder of the eccentric mechanism 300, and provides a protective cover and support for the internal portions of the eccentric mechanism. The rotary table 301 is connected to a driving plate 306 by pivot link 800 which is more clearly shown in FIG. 8.
Referring briefly to FIG. 8, pivot link 800 is comprised of a cap screw 802 surrounded by an annular lug 804 mounted in a hole 806 on a peripheral tang 702 of driving plate 306; the tang 702 is best shown in FIG. 7. Screw 802 and lug 804 extend below driving plate 306 into one of slots 704 in rotary table 301 having the shape of an inverted "T" and extending from the edge of the rotary table 301 a distance toward its center along a radius of the table; the slot 704 contains a T-nut 810 having threaded engagement with cap screw 802 which extends into slot 704 farther than does annular lug 804. A smaller diameter portion on the bottom side of lug 804 has a close fit with the narrower portion of slot 704 and hence torque may be transmitted from rotary table 301 through lug 804, which is retained firmly against rotary table 301 by cap screw 802 and T-nut 810, to driving plate 306. The portion of annular lug 804 which passes through the hole 806 is sufficiently smaller than hole 806 to avoid contact with the hole except for a raised collar 812 which has sliding contact with a spring plunger 814 and the inside of hole 806. Spring plunger 814 lies in an X-Z plane as does driving plate 306 and has threaded engagement with the plate. Spring plunger 814 projects into hole 806 and provides a constant contact pressure between raised portion 812 and hole 806 so that backlash is minimized and reduced to a constant amount regardless of the direction of rotation of the rotary table 301. As shown in FIG. 7, the pivot link 800 is as far away from the center of driving plate 306 as possible to reduce the effect of backlash and the deflection caused by the force giving rise to the moment rotating plate 306.
Turning to FIG. 4, driving plate 306 is secured to lower eccentric adjustment guide 403 by cap screws 402. As may be seen from FIGS. 3 an 4 in conjunction, lower eccentric adjustment guide 403 is an integral solid comprised chiefly of a rectangular plate with an integral cylindrical column extending from the plate into a hollow cylindrical portion of eccentric mechanism housing 304. The lower eccentric adjustment plate 403 is supported within the housing 304 by heavily preloaded angular-contact ball bearings 404 which also further reduce mechanical backlash in the eccentric mechanism 300. Driving plate 306, a spacer 408, a labyrinth ring 410 and the lower eccentric adjustment guide 403 combine to locate the inner and outer races of ball bearings 404 and thus preload the bearings. Because the rotation of the eccentric mechanism 300 is limited to less than one complete revolution, bearings 404 contribute to a high degree of repeatability because each ball tends to act as though geared to the races it is held between. Dimensional changes in the eccentric mechanism 300, which might occur when the eccentric mechanism is calibrated in a given position and then later returned to that position, are minimized.
Labyrinth ring 410 engages eccentric lower adjustment guide 403 in a double tongue-and-groove relationship and is secured to eccentric mechanism housing 304 by cap screws 412. The purpose of the labyrinth seal formed by guide 403 and ring 410 is to insure that particles resulting from machining operations are not carried into bearings 404 by the oil bath on the micromachining tool system. Were particles to reach bearings 404, the accuracy of the system would be destroyed.
As can be seen in FIGS. 3 and 6, upper and lower guides 401 and 403 can slide with respect to each other. A tongue 430 on lower guide 403 engages a groove 432 on upper guide 401; refer also to FIG. 4. For repeatability and reduction of backlash, constant contact pressure is maintained between tongue 430 and groove 432 by two spring plungers 414 bearing against the tongue 430. The spring plungers 414 have threaded engagement with the rectangular plate portion of upper guide 401. The actual amount of offset in the present version of the micromachining tool system is about 10 cm. The offset from the Y axis is measured by a laser interferometer using interferometer platforms 310 and 312, shown in FIG. 3, platform 310 moves with the upper eccentric adjustment guide 401 and platform 312 is stationary with respect to housing 304, since it is fixed thereto. Upper and lower eccentric adjustment guides 401 and 403 are clamped together by cap screws 602 passing through slots 604 in the upper guide 401 and having threaded engagement with the lower guide 403. A strap washer 606 is used for each pair of cap screws so that, when the guides 401 and 403 have been offset, tightening of a cap screw 602 will not turn a conventional washer under the cap screw which could conceivably cause relative movement between the guides.
Offsetting of guides 401 and 403 is accomplished by offset screw 608 shown in FIG. 6 which has threaded engagement with a screw mount 610 attached to an end of the rectangular plate of upper adjustment guide 401. An inner end of offset screw 608 bears against an end of the rectangular plate of lower adjustment guide 403 and hence the combination of offset screw 608 and upper adjustment guide 401 behaves as a traveling nut mechanism. The offset may be set to an accuracy of ±125 nm and calibrated to an accuracy of ±25 nm by laser interferometer.
Continuing with FIG. 4, the upper eccentric adjustment guide 401 is roughly similar in shape to the lower guide 403, that is, a generally rectangular plate with a cylindrical column existing from the rectangular plate. The rectangular plate portion of guide 401 contains on its lower side the groove 432 which mates with the tongue 430 on lower guide 403. The upper guide 401 also contains the slots 604 shown in FIG. 6 and previously described. On the side of the rectangular plate opposite the groove 432 in guide 401 is a central rib 416 wider and higher than the groove and extending parallel to the groove for the full length of the rectangular portion of the upper guide 401; the rib adds rigidity and mass to the upper guide 401 and substitutes for the strength lost due to the groove 432.
Referring principally to FIG. 4, extending from the rib 416 on top of the eccentric adjustment guide 401 is a cylindrical column 418 which supports the tool bar end bearing plate 501 and eccentric reference ball 400. The column 418 has a larger diameter portion nearer its juncture with rib 416. The larger diameter portion is connected to the remainder of the cylindrical column by a ledge 420, the surface of which is at a right angle to the axis of the cylindrical column 418. Ledge 420 supports the inner races of two courses of heavily preloaded angular-contact ball bearings 314. Bearings 314 permit rotation of the tool bar 500 and tool bar end bearing plate 501 by the linear air bearing 1000 with respect to column 418. At the same time, bearings 314 minimize backlash along and transverse to the axis of column 418, behaving in the same fashion as bearings 404 and 406 on the lower guide 403. The inner races of bearings 314 surround column 418 and are clamped between ledge 420 and a lock washer 424 and lock nut 426 having threaded engagement with an end of cylindrical column 418. The outer races of bearings 314 are clamped in place between the botton inside surface of tool bar end bearing plate 501 and a locking ring 428 attached to tool bar end bearing plate 501 by cap screws 440.
The top of column 418 has a circular recess 442, the base of which is parallel to the X-Z plane. Next, a shim 444 rests in the bottom of the recess 442 for Y axis adjustment. A disk 446 placed on top of the shim 444 has a spherical depression in its upper surface the same radius as the eccentric reference ball 400 which rests in the depression. The disk 446 and shim 444 may be clamped in position in the recess by cap screws 448. The height of the eccentric reference ball 400 is adjusted so that the center of the ball is at the same height as the Z axis passing through the center of the workpiece 174. The center of the eccentric reference ball 400 is adjusted by set screws 450 to place the center of the ball exactly on the Y axis as well. Set screws 450 have threaded engagement with the circular column 418 and bear against the periphery of disk 446. The accuracy of location of the ball 400 on the axes described is ±250 nm with respect to the Y and Z axes. Cover 452 anchored to locking ring 428 by screws 454 protects the ball 400 when measurements are not being made. It also prevents contaminants from entering bearings 314.
Tool bar end bearing plate 501 is essentially a cantilevered beam extending from cylindrical column 418 and supporting tool bar 500. Referring to FIG. 5, one end of the bearing plate 501 has an open-ended trough 502 in it of the same width as the tool bar 500. The tool bar 500 rests in trough 502, also shown in FIG. 3. The bottom of trough 502 lies in an X-Z plane. The tool bar 500 is clamped in place by tool bar clamp 316 shown in FIG. 3 which is attached to bearing plate 501 by cap screws 318.
Referring to FIGS. 5 and 9 in conjunction, shimming clamp 900 is comprised of two semicircular slots 902 which lie on one side of the trough 502 in a Y-Z plane and which separate the bottom of the trough from the side of the tool bar end bearing plate 501. The dual arrangement permits shimming of the tool bar 500 no matter where it rests in trough 502; in FIG. 5, only the slot 902 away from the eccentric mechanism 300 is actually in use. Each slot 902 is intersected by three blind holes 904; all three penetrate the side of plate 501, pass through the slot 902 and shim 906 and terminate in the base of the trough 502 a distance beyond each slot 902. The holes 904 are perpendicular to the plane of the slots 902. The slots 902 and blind holes 904, which are threaded to receive cap screws 905, cooperate to hold shims 906 inserted between the sides of the tool bar 500 and trough 502 to adjust the position of the tool bar 500 with respect to the Z axis; the tool bar must lie parallel to the Z axis within ±125 nm. Shims 906 are curved to match slots 902 on their lower edges, have holes through which cap screws 905 pass, and extend above slots 902 between tool bar 500 and the side of trough 502 to provide the shimming effect. Also, additional clamping effect on the tool bar 500 is provided.
The end of the tool bar 500 away from the tool bar end bearing plate 501 is supported by the linear air bearing 1000 and pivot bearing 1100 which is attached to the X slide 162. Referring to FIGS. 10, 11 and 12, the tool bar 500 slides through the linear air bearing 1000 and is attached movably thereto by bellows 1002 and 1004. Bellows 1002 and 1004 prevent entry of oil and machining particles into the linear bearing 1000 while still permitting movement of tool bar 500. The linear air bearing 1000 has the shape of a parallelepiped with a cylindrical stub 1006 projecting pendently from the bearing. Linear air bearing 1000 is split into upper half 1102 and lower half 1104 along a diagonal as shown in FIG. 11. Construction of linear air bearing 1000 in two segments 1102 and 1104 permits easy disassembly and removal of tool bar 500 from the bearing 1000. Halves 1102 and 1104 are not in contact with each other. Tool bar 500 rests on an air film issuing from oval graphite pads 1008; a row of these graphite pads 1008 is mounted on each of the inner surfaces of halves 1102 and 1104. The long axes of the oval pads 1008 are parallel and at right angles to the Z axis. The graphite pads 1008 in the upper half 1102 are held against tool bar 500 by a rocker arm 1106 and rocker ball 1108. Ball 1108 is trapped between spherical depressions 1110 and 1112 in the upper half 1102 of the linear air bearing 1000 and rocker arm 1106 respectively; the depression 1110 in upper half 1102 is located on the edge formed by the intersection of the outer surfaces parallel to the Y-Z and X-Z planes of upper half 1102 and approximately midway along the length of the linear air bearing 1000 in the direction of the Z axis. The depression 1112 in rocker arm 1106 is located at the intersection of the horizontal and vertical surfaces of the arm nearer upper half 1102 so that, when rocker arm 1106 is attached to lower half 1104 by cap screws 1114 having threaded engagement only with lower half 1104, the ball will be trapped in the aforementioned depressions 1110 and 1112. Note that cap screws 1114 pass through holes 1116 in upper half 1102 and have no contact with upper half 1102. The purpose of this arrangement is to permit upper half 1102 to rotate in a small arc having as its center of rotation the center of ball 1108. This is necessary to insure identical spacing of graphite pads 1008 from all four sides of the tool bar 500; uneven pressure on one side of tool bar would result in an error in the position of the tool bit 200 shown in FIG. 10.
Returning to FIGS. 10 and 11, each graphite pad 1008 is seated in an oval recess 1010 slightly larger than the pad. Air at a pressure of about 483 KPa is supplied through primary air passages 1118 and secondary air passages 1120 to troughs 1122 parallel to the long axis of each oval recess 1010 and formed in the base thereof. The air then passes through the porous graphite pads 1008 and supports the tool bar 500 about 6250 nm away from the pads. By supporting tool bar 500 in this fashion, friction is reduced to the minimum possible value and the tool bar is provided with equal support on all four sides, thus tending to reduce backlash and provide repeatability in the movements of tool bar 500. Also, as tool bar 500 moves from side to side or up and down in air bearing 1000, the air pressure on that side will increase due to the smaller gap, thus tending to push the tool bar 500 away since air pressure on the opposite side of the tool bar 500 will have decreased due to the larger gap. The wavelength of the errors (about ±25 nm) in the surfaces of the tool bar 500 are around 5 cm; this is short compared to the length of the linear air bearing 1000, about 22.5 cm. Hence, the air bearing 1000 averages the errors in tool bar 500, resulting in erroneous movements of the tool bar 500 considerably less than ±25 nm.
The linear air bearing 1000 is supported by the pivot bearing 1100 via two double courses of heavily preloaded angular-contact ball bearings 1012. The inner races of the upper set of ball bearings 1012 surround the cylindrical stub 1006 where the stub joins lower half 1104. The inner races of the other set of bearings 1012 surround cylindrical stub 1006 at the end of the stub away from lower half 1104. The inner races are separated by spacer 1014. The outer races of both sets of bearings 1012 have an interference fit with pivot bearing housing 1016 which is in turn attached to X slide 162 by cap screws 1202, shown best in FIG. 12, having threaded engagement with X slide 162. Also, the outer race of the bottom course has a flange 1013 which is trapped in a mating recess on pivot bearing housing 1016 by an end plate 1022 which is retained against the housing 1016 by cap screws 1024. The inner races of the lower set of bearings 1012 are held against spacer 1014 by a bearing plate 1018 attached to stub 1006 by cap screws 1020. The end of pivot bearing housing 1016 is closed by end plate 1022.
A synthetic rubber O-ring gasket 1026 is trapped between annular flanges 1028 and 1030 extending downward from the bottom of lower half 1104 and upward from the upper end of pivot bearing housing 1016, respectively. The flanges 1028 and 1030 overlap; flange 1028 surrounds flange 1030 and O-ring gasket 1026 is trapped therebetween. The O-ring gasket 1026 protects the pivot bearing 1100 against contamination of particulates resulting from machining operations.
Support and adjustment of the tool bit 200 is accomplished by the tool head 1300 shown in detail in FIGS. 13, 14, 14A, 15 and 16. The tool head 1300 permits adjustment of the tool bit 200 in X, Y and Z directions. Furthermore, it supports one end of a tool bar length standard 1900 described later.
Referring jointly to FIGS. 13, 14, 15, and 16, the tool head 1300 consists of a head piece 1600 which supports a tool holder 1402, best shown in FIG. 14, in which tool bit 200 is mounted. Head piece 1600 provides for adjustment of tool bit 200 along the Z axis; for adjustment in the X and Y directions, both head piece 1600 and tool bit 200 are moved. Head piece 1600 contains a rectangular opening 1602 in its front face 1604 which faces the workpiece 174. The opening 1602 lies along the Z direction and receives tool holder 1402; contiguous to a portion of the bottom of opening 1602 is a trough 1606 which receives a tab 1408 on tool holder 1402 which has threaded engagement with one end of a differential screw 1306. The trough 1606 terminates in a front face 1604 of the head pice 1600. The other end of differential screw 1306 has threaded engagement with head piece 1600 in threaded hole 1608 which extends from trough 1606 away from the front face 1604. Thus, by adjustment of differential screw 1306, the tool holder 1402 and tool bit 200 may be moved in or out of head piece 1600 in the Z direction.
When adjusted to the desired position, tool holder 1402 can be clamped in position by screws 1501 in FIG. 15 having threaded engagement with holes 1610 in head piece 1600 and bearing against a gib 1410 which forces the gib against tool holder 1402 and clamps the tool holder in position between the gib 1410 and the sides of rectangular opening 1602. Gib 1410 closely fits a triangular space formed by two sides of rectangular opening 1602 and a blunted edge of tool holder 1402. Two screws 1501 are used to adjust gib 1410; the center screw 1501 locks tool holder 1402 in position.
Referring to FIG. 15, tool bit 200 is positioned in a close fitting rectangular tool bit hole 1500 the axis of which is parallel to the Z axis; the tool bit is locked in position by driving an offset portion of rotating cam 1504 against tool lock plunger 1508 which is mounted slidably in a plunger hole 1510 which is in communication with both cam hole 1506 and tool bit hole 1500; plunger 1508 has a "V" cut in its end bearing against tool bit 200. Cam hole 1506 communicates with a front face 1409 of tool holder 1402 and is rotated by a wrench. A spring plunger 1512 having threaded engagement with tool holder 1402 engages a notch in tool lock plunger 1508 and retains plunger 1508 in plunger hole 1510 when the tool bit 200 is removed.
Head piece 1600 is attached to tool bar 500 by a spool 1308 shown partially broken away in FIG. 13; spool 1308 is a hollow cylinder, with its axis parallel to the Z axis and having a flange 1310 at one end and diametrically opposed ears 1312 at the other end. The flange 1310 engages a mating flange 1314 on a hole at the end of tool bar 500 when the spool 1308 is inserted through the hole. The head piece 1600 surrounds the end of the spool 1308 having ears 1312; the ears 1312 bayonet lock with head piece 1600 by passing through gaps 1612 in a flange 1614 on a rear face 1616 of head piece 1600; and rotating the spool 1308 to engage the ears 1312 with the flange 1614. The spool is inserted from the rear of tool bar 500 and flange 1314 has gaps not shown which are similar to gaps 1614 to allow passage of the ears 1312. A drain hole 1615 allows oil supplied to tool bar 500 via funnel 185 and hole 503 to drain out of the tool bar.
The spool 1308 passes through an X-direction guide 1316 and traps it between tool bar 500 and head piece 1600.
Once inserted into the head piece 1600 and rotated, the spool 1308 is locked by friction locks (refer to FIGS. 14, 14A, 15, and 16) comprised of cylindrical slugs 1420 each having a slot 1422 and closely fitting in blind lock holes 1618 in head piece 1600 which interrupt a groove 1620 behind flange 1614 and communicate with front face 1604; ears 1312 on spool 1308 rest in groove 1620. Slots 1422 are formed in the curved surface of slugs 1420, with the long axes of the slots forming right angles with the long axes of the cylindrical slugs. The slots 1422 in slugs 1420 are aligned with groove 1620 and of slightly less width; ears 1312 are turned far enough to engage simultaneously the slots and groove 1620. A screw 1404 has threaded engagement with each slug 1420. One end of the screw bears against an end of a dowel 1405 mounted slidably within the slug. Turn to FIG. 14A; the long axes of screw 1404 and dowel 1405 lie on the same straight line, parallel to but offset from the long axis of the slug 1420. The opposite end of screw 1404 is adjustable at an end of slug 1420 at face 1604 of head piece 1600; the opposite end of dowel 1405 protrudes from the opposite end of slug 1420 and bears against a flat bottom of blind lock hole 1618. Turning screw 1404 moves dowel 1405 out of slug 1420; the slug moves toward front face 1604, thus causing one side of slot 1422 to press firmly against a surface of ear 1312 nearer the tool bar 500. Consequently, since spool 1308 is engaged with flange 1314, the head piece 1600 and the X direction guide 1326 are brought tightly against tool bar 500. Furthermore, the binding effect between slot 1422 and ear 1312 prevents rotation of the spool 1308.
The tool bar has two Y direction guide rails 1412 in a Y-Z plane formed by extension of each side of the tool bar 500 beyond the end of the tool bar. A parallelepipedal X direction guide 1316 rests between the guide rails 1412. The guide rail 1316 fits closely between guide rails 1412 and can slide in the Y direction between the guide rails. The position of tool bit 200 in the Y direction is controlled by set screws 1322 having threaded engagement with tabs 1324 and bearing against the top and bottom surfaces of the X direction guide 1316. Tabs 1324 are screwed to the top and bottom surfaces of tool bar 500.
X direction guide 1316 has a large spool hole 1326 through its center which permits spool 1308 to pass through the guide and also provides space for the tool bar length standard 1902. X direction guide 1316 has two rails 1328 formed as extensions of its top and bottom surfaces in X-Z planes. Head piece 1600 fits closely and slidably between guide rails 1328 and may be moved in the X direction by adjusting set screws 1414 which have threaded engagement with Y-direction tabs 1416 projecting beyond the end of the tool bar 500 and which bear against the side surfaces of head piece 1600. X-direction tabs 1416 are screwed to X direction guide 1316 and project. Therefore, tool bit 200 may be adjusted in the X, Y and Z directions by making adjustments only to tool head 1300; once initial calibration is complete, the entire setup calibration, necessary with each tool change, is accomplished by adjustments at the tool head 1300 only.
Initial calibration is accomplished with a pivot axis calibrating device 1700, the tool bar length standard 1900, a tool bar length calibration insert 1922, a tool height and offset calibration insert 2300 and a tool calibration fixture 2600. Setup calibration is accomplished by the tool calibration fixture 2600, and a mastering station 2900, all described below.
Prior to use, the omega-X machine must be initially calibrated with a pivot axis calibrating device 1700 which permits the distance between the Y axis and the pivot axis of the pivot bearing 1100 to be established with an accuracy of ±25 nm; this distance is then supplied to the dedicated computer. The Y axis is represented by the eccentric reference ball 400 and the pivot axis, which is parallel to the Y axis, of the pivot bearing 1100 is represented by a pivot reference ball 1704 supported on the pivot bearing 1100 by an adjustable support 1703 identical to column 418, recess 442, shim 444, disk 446, cap screws 448, and set screws 450. The position of the pivot reference ball 1704 may be adjusted in the same fashion as that described for the eccentric reference ball 400. The pivot axis calibrating device 1700 consists essentially of a standard of known length with a linear variable differential transformer used to make a fine adjustment to the known standard. The hollow calibrating device shaft 1706 is made of a stable corrosion and wearresistant material such as a nitrided steel whose length is calibrated and certified by the National Bureau of Standards or by a metrology laboratory with gages traceable to the National Bureau of Standards. Mounted concentrically within the shaft 1706 is an air-operated linear variable differential transformer (LVDT hereinafter) which is a commercially available length measurement device attached to an electrical power source, air source, and readout instrument by cable 1710. The position of the LVDT 1708 may be adjusted by a surrounding differential screw 1712 rotatable by means of a manually operated ring 1714 accessible through a hole 1716 in the shaft 1706. LVDT 1708 is clamped tightly in a front nut 1718 by a clamp screw 1720. Front nut 1718 has threaded engagement with one end of the differential screw 1712 and fits slidably inside shaft 1706. Key 1719 slides in keyway 1721 and prevents rotation of front nut 1718; see FIG. 19. Two spring plungers 1723 having threaded engagement with front nut 1718 bear against the inner surface of shaft 1706 and insure contact pressure; holes 1725 allow access to adjust the spring plungers. The other end of differential screw 1712 has threaded engagement with rear nut 1722 which is fixed inside shaft 1706 by set screw 1724 which expands a split portion of rear nut 1722 against the interior of shaft 1706. Set screw 1724 is accessible through hole 1726 in shaft 1706. At the end of shaft 1706 opposite the LVDT 1708, two diametrically opposed pins 1802 extend from the exterior of shaft 1706. Pins 1802 provide support for a rubber band 1804 which is used to bring a flat reference surface 1734 on a closed end of shaft 1706 against the pivot axis reference ball 1704. The contact is minimized by using a rubber band and made repeatable by using the same type and size of rubber band. Excessive contact pressure between the reference surface 1734 and pivot axis reference ball 1704 could cause a slight indentation and erroneous readings on the order of 75 nm.
Shaft 1706 is supported by half sleeves 1728 and 1730, each of which is held against the upper portion of shaft 1706 by rubber bands 1738 and extends beyond an end of shaft 1706. Half sleeve 1728 also rests atop pivot axis reference ball 1704, while half sleeve 1730 rests atop eccentric reference ball 400; the half sleeves support shaft 1706 so that the center lines of the shaft 1706 and LVDT 1708 are coaxial with the Z axis on which both the eccentric reference ball 400 and pivot reference ball 1704 must be located before the pivot axis calibrating device 1700 is employed.
In use, a zero reading of the LVDT 1708 is established by wringing a gage block (not shown) against a lapped open end 1736 of the shaft 1706 through which the probe 1732 of the LVDT 1708 extends; the probe 1732 is adjusted by ring 1714 to contact the gage block and the LVDT 1708 output is then adjusted to a null reading. The pivot axis calibrating device 1700 is then placed between reference balls 400 and 1704 and is held in contact with pivot axis reference ball 1704 by rubber band 1804. The reference balls 400 and 1704 have previously been adjusted so that their centers lie on the Z axis and, in the case of eccentric reference ball 400, on the Y axis and, in the case of pivot axis reference ball 1704, on the pivot axis of the pivot bearing 1100 to an accuracy of ±25 nm. The distance between the centers of balls 400 and 1704 must be determined by conventional means to approximately 0.0127 cm beforehand. Once the pivot axis calibrating device 1700 is in position, the LVDT 1708 is moved by air through cable 1710 until the probe 1732 contacts eccentric reference ball 400, at which time the LVDT correction to the known standard length of shaft 1706 is determined, thus measuring to an accuracy of ±25 nm the distance between the centers of eccentric reference ball 400 and pivot reference ball 1704. This dimension is supplied to the dedicated computer.
Because conventional means do not provide sufficient accuracy in calibration of the tool position with reference to the eccentric reference ball 400, a tool bar length standard 1900 is employed. The length standard 1900 is in several respects functionally and structurally similar to the pivot axis calibrating device 1700. The purpose of the tool bar length standard 1900 is to locate a point in space along the Z axis exactly one meter away from the center of the eccentric reference ball 400, the center of which is located both on Y and Z axes. Length standard 1900 employs a known length calibrated and certified by the National Bureau of Standards or by a metrology laboratory with gages traceable to the National Bureau of Standards. The standard length is correctable by means of an LVDT 1708 used in exactly the same manner as in pivot axis calibration device 1700.
Referring to FIG. 19, the tool bar length standard 1900 is composed mainly of a hollow multidiameter shaft 1904. The shaft 1904 contains the LVDT 1708 whose probe 1732 rests against the eccentric reference ball 400. The common axes of the shaft 1904 and LVDT 1708 lie on the Z axis. The LVDT 1708 is adjustable by means of a differential screw 1712 which has threaded engagement with front and rear nuts 1718 and 1722.
The tool bar length standard 1900 passes through the hollow tool bar 500. FIGS. 1 and 5 show a tool bar length standard hole 503 through which the standard 1900 passes. At the end of standard 1900 away from reference ball 400 the shaft 1904 passes out of tool bar 500, through spool 1308, head piece 1600 and protruding from a tool bar length calibration insert 1922, which is installed in head piece 1600 in place of tool holder 1402. Besides supporting one end of the length standard 1900, the calibration insert 1922 permits the end of the length standard 1900 to be aligned so that its axis coincides with the Z axis. To accomplish this, twelve set screws 2002 have threaded engagement with a cylindrical projection 2004 on the calibration insert 1922 and extend into a hole 1924 in the calibration insert through which the length standard 1900 passes. The set screws 2002 lie in an X-Y plane, bear against the periphery of the length standard 1900 and permit adjustment of the length standard 1902 which is swept into the Z axis to an accuracy of ±50 nm by an indicator, mounted on an extension bracket on the spindle 3200, which rides around the cylindrical end of shaft 1904 projecting beyond projection 2004. A differential screw 1926 has threaded engagement with both the calibration insert 1922 and head piece 1600 and is used to move the calibration insert 1922 and length standard 1900 on the Z axis exactly as the tool bit 200 is moved by differential screw 1306. Constant contact pressure is maintained between calibration insert 1922 and its recess in head piece 1302 by means of a gib 2006 and screws 1502, shown in FIG. 20.
In use, the LVDT 1708 has its null reading established by wringing a gage block against a lapped open end 1930 of the shaft 1904 through which the probe 1732 extends to touch eccentric reference ball 400. The length standard 1900 is then inserted into the calibration insert 1922 which has previously been installed in head piece 1600. The end of the length standard 1900 near the eccentric reference ball 400 is supported by the half sleeve 1730 attached to shaft 1904 by a rubber band (not shown). The half sleeve 1730 rests on the eccentric reference ball 400 and hence aligns this end of standard 1900 with the Z-axis. A supply of oil is gravity fed into tool bar 500 and around the shaft 1904 through funnel 185 and hole 503 in the end of the tool bar nearer the eccentric reference ball 400. The oil thermally stabilizes the length standard 1900 and tool bar 500; it also provides a buoyant force which supports the length standard 1900, thus eliminating sag as a source of measurement error. The wall of shaft 1904 is made sufficiently thin so that the buoyant force is approximately equal to the weight of standard 1900. Oil drains out of tool bar 500 through drain hole 1615 in head piece 1600. The length standard 1900 is aligned coaxially with the Z axis by set screws 2002 and moved back and forth on the Z axis to bring the standard 1900 within the range of LVDT 1708 similarly to the calibrating device 1700; the required accuracy, 0.0127 cm, is the same. The probe 1732 is placed in contact with the surface of the eccentric reference ball 400 by air through cable 1710. Once this has been accomplished, the differential screw 1926 moves the standard 1900 on the Z axis until the center of a spherical end 1928 of shaft 1904 represents the one meter position at which the tool bit 200 is to be located. While the length standard 1900 is still in position, this point is transferred to the calibration fixture 2600 and mastering station 2900 described below. The accuracy of location of this position is ±50 nm along the Z-axis.
To establish the reference positions for the tool bit 200 in the Y and X directions, the tool bar length standard 1900 and the bar length calibration insert 1922 are removed from head piece 1600. A tool height and offset calibration insert 2300, shown in FIGS. 23, 24 and 25, is installed in head piece 1600. Calibration insert 2300 is of the same general shape as calibration insert 1922 and tool holder 1402 except for a reference projection 2304. The reference projection 2304 has a parallelepipedal base 2306 extending from a front face 2303 of the insert 2300 along the Z axis. A locating cylinder 2308 extends from base 2306 further along the Z axis and is swept into alignment with the Z axis by an indicator mounted on the main air bearing spindle 3200. The locating cylinder 2308 terminates in a stepped partially spherical surface 2310. A step 2402 lies on the Z axis in an X-Z plane and serves as a height reference surface. A spherical portion 2312 of the surface 2310 lies below the Z axis with its radius coincidental with the Z axis. The spherical portion 2312 may serve as a Z axis reference surface. One side of the base 2306 is an offset reference surface 2502 oriented in the Y-Z plane.
The tool height and offset calibration insert 2300 is used in conjunction with a tool calibration fixture 2600, shown in FIGS. 26, 27 and 28. The tool calibration fixture 2600 is composed mainly of a yokelike structure which is hung on tool head 1300. Its purpose is to position three LVDT's, one in each direction, to measure the tool reference position from the height and offset calibration insert 2300 and tool bar length standard 1900 and to transfer these positions to the tool bit via a mastering station 2900 so that the tool bar length standard 1900 and calibration inserts 1922 and 2300 need not be used for each tool bit change once initial calibration is completed. Tool calibration fixture 2600 has a triangular head 2702 in which Z axis, Y direction, and X direction LVDT's 2704, 2604 and 2706 are respectively mounted. Each LVDT extends into a cavity 2708 visible from the side through a port 2709 in the triangular head 2702. Each LVDT is held in position by a screw-type pinch clamp; the Z axis LVDT pinch clamp 2802 is representative of all three. Two yoke arms 2710 integral with the triangular head 2702 extend along each side of the tool head 1300 and tool bar 500. A support rod 2712 is fixed to both yoke arms 2710 and is oriented with its long axis in the X direction. When the tool calibration fixture 2600 is in position, the support rod is engaged by spring plungers 2714 mounted in L-shaped clips 2716 fixed to the top of tool bar 500 and cavity 2708 is thus placed around the tool bit 200. The spring plungers 2714 provide a repeatable contact pressure against the support rod 2712. The remaining support for the fixture 2600 and location along the Z direction is provided by flats 2608 on each yoke arm 2710; the flats 2608 rest against the Y direction guide rails 1412 on the end of tool bar 500. A bias plate 2718 fixed to one yoke arm 2710 contains a set screw 2720 which locates the tool calibration fixture 2600 in the X direction and provides repeatable accuracy from one use of the fixture to the next.
The mastering station 2900 preserves measurements made by the tool calibration fixture 2600. The mastering station 2900, shown in FIGS. 29, 30, and 31, is mounted at any convenient location on the machine base 110. The mastering station 2900 records the reference positions obtained by use of the tool bar length standard 1900 used in conjunction with the tool height and offset calibration insert 2300 and the tool calibration fixture 2600. The mastering station 2900 consists essentially of an anvil 2904 which is adjustable by means of shims along three orthogonal axes. An adaptor plate 2906 serves to mount the mastering station 2902 and provides mating flats 3001 for the flats 2608 on yoke arms 2710. Attached to the adaptor plate 2906 by cap screws 2908 is holder 2910; holder 2910 is generally parallelepipedal in shape and its functions are to provide support for anvil 2904 and tool calibration fixture 2600 and to permit adjustment of anvil 2904 in the X and Y directions. Projecting from the upper surface of holder 2910 are two ears 3002 containing spring plungers 3004; ears 3002 and plungers 3004 engage support rod 2712 of the tool calibration fixture 2600 in the same way as do clips 2716 and spring plungers 2714. Projecting from the lower edge of holder 2910 is Y-axis adjustment support 2912. A cap screw 2914 passes through an oblong slot 3102 in the Y-axis adjustment support 2912, a Y-axis shim plate 3104 and has threaded engagement with an anvil holder 3106. Also projecting from the front surface of the holder 2910 is an X-axis adjustment support 3108; as in the case of the Y-axis, cap screw 3012 passes through oblong slot 3014 in the X-axis adjustment support 3108, an X-axis shim plate 3114 and has threaded engagement with the anvil holder 3106. In this fashion, the anvil holder 3106 is retained snugly against X and Y-axis shim plates 3114 and 3104 while still being movable in X and Z directions.
To adjust the anvil 2904 in the remaining axis, the anvil itself is moved with respect to the anvil holder 3106. Anvil holder 3106 is a C-shaped piece containing a guide channel 3110 for anvil 2904. As shown in FIG. 31, guide channel 3110 supports the parallelepipedal anvil 2904 on three of its four sides. After adjustment of the anvil holder 3106 in the X and Y directions, cap screw 3118, passing through oblong hole 3120 and having threaded engagement with holder 2910, is tightened to prevent further movement of the anvil holder 3106.
A base portion 2916 of anvil 2904 slides in the guide channel 3110 and contains an oblong slot 2918 through which passes a cap screw 3122 which has threaded engagement with anvil holder 3106. A tab 2920 extending pendently from base 2916 contains a hole 2922 through which cap screw 2924 passes; the cap screw also passes through a shim 2926 and has threaded engagement with anvil holder 3106. The cap screw 2924 and shim 2926 permit adjustment of the anvil 2904 in the Z direction. Spring plungers 2928 minimize backlash between base 2916 and guide channel 3110; the plungers have threaded engagement with anvil holder 3106 and bear against the upper surface of base 2918.
The anvil accepts the readings of the tool calibration fixture X direction, Y direction, and Z axis LVDT's 2706, 2604, and 2704 respectively on X direction, Y direction, and Z axis reference surfaces 3006, 3008, and 2930 respectively. X direction reference surface 3006 is formed by a flat portion in a Y-Z plane near an end of anvil 2904 away from holder 2910. Y direction reference surface 3008 is formed by a flat portion in an X-Z plane which contains the Z axis at the same end of anvil 2904. Z axis reference surface 2930 is formed by the end of anvil 2904 away from holder 2910 and lying below the Z axis which forms a quarter of a sphere.
In use, the readings obtained by the tool calibration fixture 2600 from the tool bar length standard 1900 and tool height offset and calibration insert 2300 are transferred to the mastering station 2900. The position of the anvil 2904 in the X and Y directions and on the Z axis become the reference positions for tool calibration fixture LVDT's 2604, 2706, and 2704. Then, by using only the mastering station 2900 and tool calibration fixture 2600, the tool bit 200 can be quickly located in its reference positions to an accuracy of ±25 nm in X and Y directions and on the Z axis. Note that setup calibration is accomplished by adjustments only at the tool head end of tool bar 500. Also, all LVDT's are at this end, and no risk of losing tool bar 500 to Z axis alignment exists.
The main air bearing spindle 3200 is shown in detail in FIGS. 32 through 34. Its purpose is to rotate the workpiece 174 relative to the tool bit 200; it maintains a rotational accuracy of 25 nm TIR. Referring to FIG. 32, the main air bearing spindle 3200 is comprised of a spindle 3202 rotatably supported within a spindle housing 3204. Spindle 3202 is coaxial with the Z-axis. Radial forces (in the X-Y plane) and thrust forces (along the Z-axis) are accommodated by front and rear spherical air-pressurized graphite journal bearings 3206 and 3208. Both bearings are affixed to front and rear bearing housings 3214 and 3216, which form portions of spindle housing 3204. Spherically-shaped journals 3210 and 3212 are affixed to and become a part of the spindle 3202. They rotate within bearings 3400 and are supported by an air film at the interface. Housings 3214 and 3216 are separated by and fixed to housing center 3218; the complete assembly is then fixed to base 3220 by cap screws 3222, thus forming spindle housing 3204. Hole 3219 in center 3218 provides an exhaust for lubricant air escaping from the bearings 3206 and 3208. Base 3220 is in turn rigidly attached to raised portion 170 of machine base 110; see FIG. 1.
Spindle 3202 has a hollow center 3226 which extends the entire length of the spindle. The hollow center 3226 contains a shaft 3228 which supports a tube 3230 concentric with shaft 3228 by spacers 3232. A supply of oil coolant is delivered through funnel 184, shown in FIG. 1, through the annulus between tube 3220 and shaft 3228 and spills into hollow center 3226 through holes 3234 in spacer 3232. The oil coolant shortens the time required to thermally stabilize the main air bearing spindle 3200 from a few hours to a few minutes. Shaft 3228 is stationary and is therefore supported from the front end of spindle 3202 by rotating joint 3236 rotatably mounted in gland 3238 which is in turn fixed to spindle 3202. Undesirable heating is caused by shearing of lubricant air in the front journal bearing 3206; heating also occurs in the rear journal bearing 3208 but is of a sufficiently smaller magnitude that thermal excursions may be absorbed by a flexure flange 3240 anchored to bearing base 3212 and spindle 3202 through shaft key 3242.
Once within the hollow center 3226, oil flows by centrifugal force due to rotation of the spindle through passages 3244 which extend radially outward from hollow center 3226 and which communicate the hollow center with a V-shaped trough 3246 in front spherical journal 3210. From trough 3246 the oil flow through twenty-four cooling passages 3248 to collection channel 3250. The oil flow through passages 3248 increases the heat removal rate from the front journal bearing 3206 sufficiently so that much less time is required to establish equality between heat addition and heat removal rates; the result is that thermal growth of the main air bearing spindle 3200 ceases within a few minutes of the time the spindle begins rotating the workpiece 174. From collection channel 3250 the oil flows into six outlet passages 3252 in spindle 3202; each outlet passage is terminated by a plastic orifice 3254 which controls the flow of oil. The orifices 3524 are thermally nonconductive so that heating caused by shearing of the oil as it exits the orifices is not easily transferred to spindle 3202. Centrifugal action flings the oil from spindle 3202 into circumferential tube 3256; the oil then returns by gravity to the cooler (not shown) through outlet 3258. Oil is kept from reaching the bearing by flingers 3260 screwed to spherical journals 3210 and 3212 and collector rings 3262 screwed to bearing retaining rings 3224. Circumferential tube 3256 is attached to tube support rings 3264 which is in turn screwed to collector ring 3262.
Air is supplied to graphite bearings 3400 by passages 3266 which place an air distributor trough 3268 in communication with grooves provided in graphite bearings 3400. Passages 3266 are drilled in front and rear bearing housings 3214 and 3216. Air is supplied to distribution trough 3268 by passages 3270 to which air hoses may be connected.
As shown in FIG. 34, graphite bearings 3400 contain a series of grooves 3404 on the convex surfaces of the bearings; each groove 3404 lies in an X-Y plane and is interrupted by six air ducts 3406; each air duct 3406 intersects grooves 3404 at a right angle and lies in a common plane with the Z axis and is connected to one passage 3266 so that air is distributed evenly to the grooves 3404. The air is supplied at sufficient pressure to pass through the porous graphite bearings 3400 and support the spherical journals 3210 and 3212 a distance away from their respective graphite bearings 3400.
At the rear end of main air bearing spindle 3200 a balancing wheel 3272 is retained on spindle 3202 by key 3242 and nut 3274 which has threaded engagement with a reduced diameter portion of spindle 3202.
After location of tool bit 200 by means of the tool calibration fixture 2602, the tool bit 200 has its contour gaged by a tool gage 3500, shown in FIGS. 35 and 36, and mounted on a gage arm 3502. The tool gage 3500 is essentially an electrical switch which requires extremely slight pressure to make or break the electrical circuit of the switch. As shown in FIG. 36, a metal gaging ball 3602 rests movably on a triangular glass platen 3604; also see FIG. 37. The glass platen 3604 has two electrical contact pins 3504 embedded in it near its apex, which is the part of the platen 3604 closest to the tool bit 200; the circuit of which these electrical contact pins 3504 are a part is complete when gaging ball 3602 contacts both electrical contacts 3504 which project upwardly from the surface of platen 3604. Pins 3504 are located so that when the tool gage 3500 is in position the point on the surface of ball 3602 which will contact cutting tool bit 200 is precisely known to an accuracy of ±25 nm in both X and Y directions. Glass platen 3604 is slightly inclined at an angle of 0.0667° to cause the ball 3602 to rest against pins 3504 with a force of about 0.1 gm, which is appropriate for the diamond-tipped tool bits 200 being used. The angle of glass platen 3604 is controlled by oval-headed set screws 3606 bearing against a bottom surface of platen 3604. Glass platen 3604 is retained against set screws 3606 by retaining bolt 3608 which is fixed to glass platen 3604 and which passes through an oblong hole in the top surface of a support 3508; nut 3610 has threaded engagement with retaining bolt 3608 and traps retaining spring 3612 compressively between nut 3610 and support 3508. Refer also to FIG. 38. The contact pressure between glass platen 3604 and set screws 3606 can thus be varied by tightening or loosening nut 3610.
In the Z direction, glass platen 3704 is retained by C-bracket 3614 which has a downwardly extending flange fastened to a side of the upper surface of support 3508 away from the tool bit 200. Bracket 3614 extends above the upper surface of support 3508 and has two arms 3616 which extend toward tool bit 200 and which envelop the base and a portion of the sides of the triangular glass platen 3604. Set screws 3520 and 3618 are mounted respectively in each arm 3616 and in the rear portion of C-bracket 3614 which extends above the upper surface of support 3508. Set screws 3520 and 3618 retain and position glass platen 3604 in the X and Z directions.
Support 3508 is fixed to one end of the gage arm 3502 which, as can be seen in FIGS. 35 and 1, is an L-shaped hollow arm used to move the tool gage 3500 into and out of the gaging position. Linear motion parallel to the Z axis and rotary motion in the X-Y plane is provided by a Rotolin ML 2000-2875-6 linear and rotary bearing 188. Linear motion is provided so that the tool bit 200 may be positioned as close as possible to the workpiece 174 before tool contour gaging takes place to avoid introducing errors caused by Z-axis slide 118. Gage arm 3502 and bearing 188 are supported by pedestals 189 which, in turn, are anchored to raised portion 170 of machine base 110.
Oil coolant is supplied to the linear and rotary bearing 188 and flows through gage arm 3502 through an outlet hole 3512 in support 3508; the cooling oil insures that gage arm 3502 is at a uniform temperature throughout its length. Normal room temperature variations would disturb the accuracy of the gage arm 3502 and thus the tool gage 3500.
When in the gaging position, tool gage 3500 is supported by leg 3514 which is rotatably mounted to the bottom of support 3508 through pivot block 3620 and bearing 3622. Pivot block 3620 is attached to support 3508 by cap screws 3624 through shim 3626 which permits adjustment of the position of the tool gage 3500 in the Y direction. In the gaging position, the lower end of leg 3514 terminates in a V-shaped fitting 3516 which rests on a reference bar 3518 parallel to the Z-axis and permanently attached to machine base 110 (see also FIG. 1); this insures that the center of gaging ball 3602 is aligned with the Z-axis, i.e., in the X and Y directions. The location of gaging ball 3602 in the Z direction is not important since the tool contour gaging is in the nature of a differential measurement from a known tool position to an accuracy of ±25 nm. Tool bit 200 is moved by a combination of X and omega axis motions to contact gaging ball 3602 at intervals of 1 degree throughout that portion of the nose contour of tool bit 200 to be used during a contouring cut; the portion of the nose to be used is determined by conventional mathematical methods. The position at which contact occurs is supplied to the dedicated computer.
FIGS. 37 and 38 display a workpiece gage 3700 very similar in construction and function to the tool gage 3500. The workpiece 3700 employs a gaging ball 3602 movably supported by an identical glass platen 3604. The ball 3602 and platen 3604 function in exactly the same way as they do in tool gage 3500 except that in this case the electrical circuit formed by the contacts 3504 and the ball 3602 will be broken as the ball is brought gently against the surface of the workpiece 174. Platen 3604 is mounted on an angle bracket 3704. The glass platen 3604 is adjusted and retained by means identical to that used for the tool gage 3500. The assembly of ball 3602, platen 3604 and angle bracket 3704 is attached to a yoke 3706 which is similar to yoke 2604 in the tool calibration fixture 2600. Yoke 3706 has two arms 3708 which extend toward the eccentric reference ball 400 on both sides of tool head 1300. The arms are connected by a support rod 3710 which engages spring plungers 2714 on clips 2716 fastened to the top of tool bar 500. Flats 3806 on the ends of the yoke arms facing tool bar 500 rest against mating flats on the end of tool bar 500 when the yoke 3706 is in position. Bias plate 3712 performs the same function as does bias plate 2718. The light pressure exerted by the workpiece gage 3700, less than 1.5 Pa, prevents damage to the workpiece surface. Furthermore, because the workpiece gage 3700 is mounted on the tool bar 500, the position of gaging ball 3602 can be readily established. Gaging the workpiece 174 before it is removed from spindle 3200 insures that the workpiece will not be deformed by gravitational forces. This, in turn, simplifies the determination of the source of machining errors.
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A micromachining tool system with X- and omega-axes is used to machine spherical, aspherical, and irregular surfaces with a maximum contour error of 100 nonometers (nm) and surface waviness of no more than 0.8 nm RMS. The omega axis, named for the angular measurement of the rotation of an eccentric mechanism supporting one end of a tool bar, enables the pulse increments of the tool toward the workpiece to be as little as 0 to 4.4 nm. A dedicated computer coordinates motion in the two axes to produce the workpiece contour. Inertia is reduced by reducing the mass pulsed toward the workpiece to about one-fifth of its former value. The tool system includes calibration instruments to calibrate the micromachining tool system. Backlash is reduced and flexing decreased by using a rotary table and servomotor to pulse the tool in the omega-axis instead of a ball screw mechanism. A thermally-stabilized spindle rotates the workpiece and is driven by a motor not mounted on the micromachining tool base through a torque-smoothing pulley and vibrationless rotary coupling. Abbe offset errors are almost eliminated by tool setting and calibration at spindle center height. Tool contour and workpiece contour are gaged on the machine; this enables the source of machining errors to be determined more readily, because the workpiece is gaged before its shape can be changed by removal from the machine.
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FIELD OF THE INVENTION
[0001] The present invention relates to camera positioning; more particularly, relates to transforming between image coordinates of a remote-control camera and object coordinates of a digital map by using a transformation module between the coordinates of the remote-control camera and the coordinates of the digital map.
DESCRIPTION OF THE RELATED ARTS
[0002] A first prior art proclaimed in Taiwan is called “A method for a monitoring camera”, comprising steps of: (a) notifying a happening of an accident to a control center by an alarm; (b) transforming and transferring position coordinates of the accident from a database in the control room; (c) figuring out a relationship function to obtain polar position coordinates for camera controlling commands; (d) controlling a camera on a rotating platform; and (e) transferring an image of the position for the accident back to the control center. Thus, a control center is able to monitor a large are a by controlling cameras remotely.
[0003] A second prior art, “A three-dimensional monitoring system controlled with a map”, is revealed in Taiwan for monitoring a selected target in a monitored area. The system comprises camera devices and a control device, where the camera devices are cameras distributed in the monitored area capable of taking picture at any angle by rotating; the control device comprises a system main frame and a display; the system main frame has a digital map set; and the digital map set provides at least one digital map shown on the display. When the control device receive a control command from the digital map to select a target, a rotating signal is transferred to control cameras to take photos at the target from different directions. Every image signal from camera is transferred back to form a three-dimensional image of the target shown on the display.
[0004] Although the monitored area is watched out through the above prior arts, the general remote-control camera has no calibrated parameters of panning, tilting and zooming and so positioning faces some difficulties. Hence, the prior arts do not fulfill users' requests on actual use.
SUMMARY OF THE INVENTION
[0005] The purpose of the present invention is to transforming between image coordinates of a remote-control camera and object coordinates of a digital map by using a transformation module in between.
[0006] To achieve the above purpose, the present invention is a system for camera positioning and methods thereof. The system for camera positioning comprises a camera device and a control device, where the camera device has a remote-control camera with parameters of panning, tilting and zooming; the control device comprises a control unit and a display unit; the control unit comprises an input/output (I/O) module, an image database module, a transformation module and a digital map module; the transformation module has a transformation function between image coordinates of the remote-control camera and object coordinates of a digital map in the digital map module; and the object coordinates of the digital map is obtained through inputting the image coordinates of the remote-control camera or, likewise, the image coordinates of the remote-control camera is obtained through inputting the object coordinates of the digital map. Accordingly, a novel system for camera positioning and methods thereof are obtained.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0007] The present invention will be better understood from the following detailed description of the preferred embodiment according to the present invention, taken in conjunction with the accompanying drawings, in which
[0008] FIG. 1 is the structural view showing the preferred embodiment according to the present invention;
[0009] FIG. 2 is the flow view showing the method for positioning on the digital map;
[0010] FIG. 3 is the flow view showing the method for positioning the remote-control camera; and
[0011] FIG. 4 is the flow view showing a method for building a transformation function between the image coordinates of the remote-control camera and the object coordinates of the digital map.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] The following description of the preferred embodiment is provided to understand the features and the structures of the present invention.
[0013] Please refer to FIG. 1 , which is a structural view showing a preferred embodiment according to the present invention. As shown in the figure, the present invention is a system for camera positioning and methods thereof. The system for camera positioning comprises a camera device 1 and a control device 2 , where the camera device 1 comprises a remote-control camera and the remote-control camera has parameters of panning, tilting and zooming.
[0014] The control device 2 comprises a control unit 21 and a display unit 22 , where the control unit 21 comprises an input/output (I/O) module 211 , an image database module 212 , a transformation module 213 and a digital map module 214 ; the control unit 21 is a computer; the display unit 22 displays image data and digital map; and the display unit 22 is a liquid crystal display (LCD).
[0015] Please refer to FIG. 1 and FIG. 2 , which are the structural view and a flow view showing a method for positioning on a digital map according to the present invention. As shown in the figures, the system for camera positioning has a method for positioning on a digital map, comprising the following steps:
[0016] (a) Transferring an image signal to an I/O module 31 : The camera device 1 transfers an image signal to an I/O module 211 of a control device 2 ; and the I/O module 211 transforms the image signal into image data.
[0017] (b) Storing image data and displaying image data on the display unit 32 : The image data is transferred to the image database module 212 to be stored; and the image data is transferred to the display unit 22 to be displayed.
[0018] (c) Setting a monitored position and transferring image coordinates of the monitored position to a transformation module 33 : A monitored position is set in the image data; and image coordinates of the monitored position are transferred to a transformation module 213 .
[0019] (d) Transforming the image coordinates into object coordinates 34 : The transformation module 213 transforms the image coordinates of the monitored position into object coordinates to be used in a digital map module 214 .
[0020] (e) Displaying a digital map for the position 35 : The object coordinates of the monitored position is inputted to the digital map module 214 for positioning; and both the monitored position and a digital map are transferred to be displayed on the display unit 22 .
[0021] Please refer to FIG. 1 and FIG. 3 , which are the structural view and a flow view showing a method for positioning a remote-control camera according to the present invention. As shown in the figures, the system for camera positioning has a method for positioning a remote-control camera, comprising the following steps:
[0022] (f) Choosing a monitored area and displaying a digital map of the monitored area 41 : A monitored area is chosen from a digital map module 214 ; and a digital map of the monitored area is displayed on a display unit 22 .
[0023] (g) Setting a monitored position 42 : A monitored position is set in the monitored area.
[0024] (h) Transferring object coordinates to a transformation module to be transformed into image coordinates 43 : Object coordinates of the monitored position are transferred to a transformation module; and is transformed into image coordinates to be used by the camera.
[0025] (i) Transferring image coordinates to an I/O module to be transformed into camera parameters 44 : The image coordinates of the monitored position are transferred to an I/O module 211 to be transformed into parameters of panning, tilting and zooming for a remote-control camera.
[0026] (j) Taking photo at the monitored position 45 : The three parameters are transferred for positioning the remote-control camera so that a photo at the monitored position is taken with the remote-control camera.
[0027] Please refer to FIG. 4 , which is a flow view showing a method for building a transformation function between image coordinates of a remote-control camera and object coordinates of a digital map. As shown in the figure, no matter it is to position on an electronical map or to position a remote-control camera, a transformation function in a transformation module between image coordinates of the remote-control camera and object coordinates of the digital map is required. The transformation function are obtained through the following steps:
[0028] (k) Building a parameter model 51 : A parameter model of panning, tilting and zooming for a remote-control camera is built through a bundle adjustment.
[0029] (l) Obtaining orientation parameters of the remote-control camera and other parameters 52 : A plurality of control points of the remote-control camera is corresponding to a plurality of control points of the digital map separately and is obtained to figure out orientation parameters of the remote-control camera and calibration parameters of panning, tilting and zooming of the remote-control camera through a bundle adjustment based on a collinearity equation, where a great number of ray intersections are used to build a transformation model between the image coordinates of the remote-control camera and the object coordinates of the digital map.
[0030] (m) Substituting orientation parameters and other calibration parameters in the transformation model 53 : The orientation parameters of the remote-control camera and the calibration parameters of panning, tilting and zooming of the remote-control camera obtained in the above step are substituted in the parameter model obtained in step (k) to build a transformation function between the image coordinates of the monitored position of the remote-control camera and the object coordinates of the digital map of the digital map module. The transformation function is obtained as follows:
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2
(
Y
-
Y
c
)
+
∑
i
=
1
3
R
3
i
m
i
3
(
Z
-
Z
c
)
[0031] where x a and y a are the image coordinates on an image plane of the remote-control camera; X, Y and Z are corresponding ground coordinates; X c , Y c and Z c are object coordinates of a perspective center; m 11 ˜m 33 forms a rotation parameter matrix of the remote-control camera including rotation angles to X-axis (ω), Y-axis (φ) and Z-axis (κ); f is a focal length on imaging; x p and y p are coordinates of a principle point which is an intersection point of an optical axis and the image plane; and R 11 ˜R 33 are an additional rotation parameter matrix made of parameters of panning, tilting and additional calibration parameters.
[0032] To sum up, the present invention is a system for camera positioning and methods thereof, where a transformation function between image coordinates of a remote-control camera and object coordinates of a digital map is used and the object coordinates of the digital map is obtained through inputting the image coordinates of the remote-control camera or, likewise, the image coordinates of the remote-control camera is obtained through inputting the object coordinates of the digital map. Thus, a positioning function is obtained.
[0033] The preferred embodiment herein disclosed is not intended to unnecessarily limit the scope of the invention. Therefore, simple modifications or variations belonging to the equivalent of the scope of the claims and the instructions disclosed herein for a patent are all within the scope of the present invention.
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A system is used to remotely control camera positioning. A transformation model is used. By in putting image coordinates of the monitored position form camera, the object coordinates is obtained and displayed on a digital map. By inputting object coordinates on a digital map, image coordinates for the camera is obtained. After transferring parameters for camera positioning, the camera is moved to a desired position for monitoring an area and taking a photo.
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FIELD OF THE INVENTION
[0001] The present invention relates to a system and apparatus for controlling temperatures within a combustor. More particularly, the present invention relates to a system and method for controlling the temperature of a swirler within the combustor.
BACKGROUND
[0002] Typical combustors are arranged to create a toroidal flow reversal that entrains and recirculates a portion of hot combustion products upstream towards the swirler, which serves as a continuous ignition source for an incoming unburned fuel/air mixture. This process helps to maintain proper combustion stability. However, since the hot reversal flow impinges on the swirler surface, it can create a high temperature spot at the center of the swirler and generate an uneven temperature distribution across the swirler which can lead to thermal stress.
SUMMARY
[0003] In one embodiment, the invention provides a combustor for combusting a mixture of fuel and air. The combustor includes a swirler for receiving a flow of air and a flow of fuel, the fuel and air being mixed together under the influence of the swirler, the swirler imparting a swirling flow to the fuel/air mixture. The swirler also has a central channel therethrough. A prechamber is in fluid communication with the swirler for receiving the swirling fuel/air mixture, the prechamber being a cylindrical member oriented along a central axis, the prechamber imparting an axial flow to the swirling fuel/air mixture in a downstream direction along the central axis, thereby creating a vortex flow of the fuel/air mixture having a low pressure region along the central axis. A combustion chamber is in fluid communication with and downstream of the prechamber, the combustion chamber having a greater flow area than the flow area of the prechamber, thereby permitting the vortex to expand radially and create a recirculation zone in which combustion products from combustion of the fuel/air within the combustion chamber are drawn upstream along the central axis back into the prechamber. The combustor also includes a cooling assembly received in the channel, the cooling assembly defining an axis that is co-linear with the central axis of the prechamber. The cooling assembly is in fluid communication with a source of air that is cooler than the recirculation flow and directs the cooler air in a downstream direction into the prechamber thereby creating a cooling flow.
[0004] In another embodiment, the invention provides a swirler for use with a combustor for combusting a mixture of fuel and air. The swirler includes a body having an outer side and an inner side and a plurality of flow guides on the inner side of the swirler body. The flow guides define flow paths between adjacent flow guides for guiding air in a swirling motion about a centerline of the swirler body. A first annular chamber is formed within the swirler body and is in fluid communication with guide tubes located adjacent to the entrances of the flow paths. A second annular chamber is formed within the swirler body and is in fluid communication with apertures located adjacent exits of the flow paths. A channel at the centerline of the body extends from the outer side to the inner side. A cooling assembly is received in the channel and is approximately flush with the body at the inner side.
[0005] In another embodiment, the invention provides a method of combusting fuel and air in a gas turbine engine. Fuel and air is premixed to a relatively uniform mixture adjacent a swirler surface at a front portion of a combustor. The fuel/air mixture is injected into a prechamber cylinder in a swirling motion about a centerline of the prechamber, thereby creating a vortex flow having a swirling and axial motion and having a low pressure region at the centerline. The vortex flow is conveyed axially in a downstream direction into a combustion cylinder having greater flow area than a flow area of the prechamber. The vortex flow is expanded into the combustion cylinder, wherein chemical reaction of the fuel and air occurs to form hot products of combustion. As a result of said expansion, a recirculation flow is formed at the centerline wherein the hot products are drawn upstream into the prechamber. Air is conveyed through the swirler at the centerline in a downstream direction into the prechamber, said conveyed air being cooler than the recirculation flow.
[0006] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic illustration of a recuperated, two-spool gas turbine engine including a combustor for use with an embodiment of the invention.
[0008] FIG. 2 is a schematic illustration of a recuperated, single-spool gas turbine engine including a combustor for use with an embodiment of the invention.
[0009] FIG. 3 is a schematic illustration of a simple-cycle, single-spool gas turbine engine including a combustor for use with an embodiment of the invention.
[0010] FIG. 4 is a schematic illustration of a can- or silo-type combustor inside a recuperator for use with an embodiment of the present invention.
[0011] FIG. 5 is a schematic illustration of a swirler, prechamber and combustion chamber according to an embodiment of the invention.
[0012] FIG. 6A is front perspective view of a radial swirler according to an embodiment of the invention.
[0013] FIG. 6B is an exploded view of the swirler of FIG. 6A , a combustor flange and a combustor.
[0014] FIG. 7 is rear perspective view of the radial swirler of FIG. 6A .
[0015] FIG. 8 is a cut-away view of the swirler of FIG. 6A .
[0016] FIG. 9 is a sectional view of the cooling assembly of FIG. 8 .
[0017] FIG. 10 is a front view of the distribution ring of FIG. 9 .
[0018] FIG. 11 is a sectional view of the distribution ring of FIG. 10 taken along line X-X.
[0019] FIG. 12 is a front view of the heat shield of FIG. 9 .
[0020] FIG. 13 is a sectional view of the heat shield of FIG. 12 taken along line Y-Y.
DETAILED DESCRIPTION
[0021] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
[0022] The invention described herein can be used for burning various hydrocarbon fuels in a gas turbine. The combustion process comprises a method to burn lean premixed and lean pre-vaporized premixed fuel/air (F/A) mixtures. This enables lower gas turbine exhaust emissions (NOx, CO, VOC's) at a wide range of operating engine conditions.
[0023] Referring now to the drawings, like numerals are used throughout to refer to like elements within a gas turbine and combustor.
[0024] FIG. 1 schematically illustrates a recuperated gas turbine engine 10 having a two spool configuration used for generating electricity. The engine 10 includes a compressor 12 , a recuperator 13 , a combustion chamber 15 , a gasifier turbine 16 , a power turbine 17 , a gearbox 18 , and an electric generator 19 . The engine 10 communicates with an air source 20 upstream of compressor 12 . The air is compressed and routed into recuperator 13 . In recuperator 13 , the compressed air is preheated by exhaust gases from the power turbine 17 and routed into the combustion chamber 15 . Fuel 22 is then added to the combustion chamber 15 and the mixture is combusted (as described in greater detail below).
[0025] The products of combustion from the combustion chamber 15 are routed into gasifier turbine 16 . The F/A ratio is regulated (i.e. the flow of fuel is regulated) to produce either a preset turbine inlet temperature or preset electrical power output from generator 19 . Turbine inlet temperature entering gasifier turbine 16 can range within practical limits between 1500F and 2000F. The hot gases are routed sequentially first through the gasifier turbine 16 and then through the power turbine 17 . Work is extracted from each turbine to respectively transfer power to the compressor 12 and the generator 19 , with shaft power transferred through gearbox 18 . The hot exhaust gases from the power turbine 17 are then conveyed through the recuperator 13 , where heat is transferred by means of thermal convection and conduction to the air entering the combustion chamber 15 . An optional heat capturing device 24 can be used to further capture the exhaust heat for productive commercial uses. Heat capturing device 24 can be used to supply hot water, steam, or other heated fluid to device 26 which uses said heat for a variety of purposes.
[0026] FIG. 2 schematically illustrates a recuperated gas turbine engine 10 a used for generating electricity. Gas turbine 10 a is similar to FIG. 1 , with the exception that only a single turbine is used. The engine 10 a includes a compressor 12 , a recuperator 13 , a combustion chamber 15 , a turbine 16 , a gearbox 18 , and an electric generator 19 . The engine 10 a communicates with an air source 20 upstream of compressor 12 . The air is compressed and routed into recuperator 13 . In recuperator 13 , the compressed air is preheated by exhaust gases from turbine 16 and routed into the combustion chamber 15 . Fuel 22 is then added to the combustion chamber 15 and the mixture is combusted (as described in greater detail below).
[0027] The products of combustion from the combustion chamber 15 are routed into turbine 16 . The F/A ratio is regulated (i.e. the flow of fuel is regulated) to produce either a preset turbine inlet temperature to turbine 16 or preset electrical power output from generator 19 . Turbine inlet temperature can range within practical limits between 1500F and 2000F. Work is extracted from the turbine to transfer power to both compressor 12 and the generator 19 , with shaft power transferred through gearbox 18 . The hot exhaust gases from turbine 16 are then conveyed through the recuperator 13 , where heat is transferred by means of thermal convection and conduction to the air entering the combustion chamber 15 . An optional heat capturing device 24 can be used to further capture the exhaust heat for productive commercial uses. Heat capturing device 24 can be used to supply hot water, steam, or other heated fluid to device 26 which uses the heat for a variety of purposes.
[0028] FIG. 3 schematically illustrates a simple-cycle gas turbine engine 10 b used for generating electricity. Gas turbine 10 b is similar to FIG. 2 , with the exception that no recuperator exists. The engine 10 b includes a compressor 12 , a combustion chamber 15 , a turbine 16 , a gearbox 18 , and an electric generator 19 . The engine 10 b communicates with an air source 20 upstream of compressor 12 . The air is compressed and routed into combustion chamber 15 . Fuel 22 is then added to the combustion chamber 15 and the mixture is combusted (as described in greater detail below).
[0029] The products of combustion from the combustion chamber 15 are routed into turbine 16 . The F/A ratio is regulated (i.e. the flow of fuel is regulated) to produce either a preset turbine inlet temperature or preset electrical power output from generator 19 . Turbine inlet temperature to turbine 16 can range within practical limits between 1500F and 2000F. Work is extracted from the turbine 16 to transfer power to both compressor 12 and the generator 19 , with shaft power transferred through gearbox 18 . The hot exhaust gases from turbine 16 are then conveyed to either the exhaust, or an optional heat capturing device 24 can be used to further capture the exhaust heat for productive commercial uses. The heat capturing device 24 can be used to supply hot water, steam, or other heated fluid to device 26 which uses said heat for a variety of purposes.
[0030] FIGS. 1-3 illustrate gas turbine component arrangements that can be used with various embodiments of the invention. A variety of other engine configurations (multiple spools, multiple compressor and turbine stages) could also be used in conjunction with the invention. For example, instead of using gearbox 18 and generator 19 , one could use a high-speed generator to generate a high-frequency alternating current (AC) power signal, and then use a frequency inverter to convert this to a direct current signal (DC). This DC power could then be converted back to an AC power supplied at a variety of typical frequencies (i.e. 60 Hz or 50 Hz). The invention is not limited to the gas turbine configurations of FIGS. 1-3 , but includes other component combinations that rely on the Brayton cycle to produce electric power and hot exhaust gases useful for hot water generation, steam generation, absorption chillers, or other heat-driven devices.
[0031] FIG. 4 illustrates a recuperator 50 . Recuperator 50 can be similar to the recuperator disclosed in U.S. Pat. No. 5,983,992, issued Nov. 16, 1999, the entire contents of which are incorporated herein by reference. The recuperator 50 includes a plurality of stacked cells 54 that are open at each end to an inlet manifold 56 and an outlet manifold 58 and which route the flow of compressed air from the inlet manifold 56 to the outlet manifold 58 . Between the cells 54 are exhaust gas flow paths that guide the flow of hot exhaust gas between the cells 54 . There are fins in the cells 54 and in the exhaust gas flow paths to facilitate the transfer of heat from the hot exhaust gas to the cooler compressed air mixture.
[0032] With continued reference to FIG. 4 , the outlet manifold 58 contains a silo or tubular combustor 52 and a swirler 60 . Air entering outlet manifold 58 flows around the outside of the combustor 52 . The air then flows into the combustor 52 through a variety of orifices and slots in combustor 52 and swirler 60 , and exits the combustor 52 with a flow as indicated by arrow 62 . The overall flow 62 of the air in the combustor 52 can be considered to define an orientation of the combustor 52 with the flow 62 being oriented in a downstream direction, i.e., from left to right, such that the swirler 60 is upstream of the combustor 52 .
[0033] FIG. 5 shows a cross-sectional view of the swirler 60 and a portion of the combustor 52 . The combustor 52 includes a prechamber 64 and a combustion chamber 66 that is downstream of the prechamber 64 . As illustrated, the prechamber 64 has a smaller diameter than the combustion chamber 66 . Compressed air from the outlet manifold 58 is conveyed sequentially downstream through the swirler 60 to the prechamber 64 , and then to combustion chamber 66 , inside combustor 52 . Air flows into the prechamber 64 through the swirler 60 . Air pressure in the outlet manifold 58 is higher than the air pressure inside the combustion chamber 66 , and this pressure difference provides the energy potential to convey air through the swirler 60 .
[0034] FIGS. 6-8 show the swirler 60 according to an embodiment of the invention. The swirler 60 is disc-shaped and includes a body 135 and a cooling assembly 200 . The body 135 defines an inner annular chamber 137 , an outer annular chamber 139 and a plurality of flow guides 145 . The body 135 further includes a circumferential flange 150 that facilitates the attachment of the swirler 60 to the recuperator 50 . The flange 150 separates the swirler 60 into an outer portion or side 155 and an inner portion or side 160 that faces the prechamber 64 . The inner side 160 faces the combustion chamber 66 , while the outer portion 155 faces away. As illustrated herein, the swirler 60 is a separate component that attaches to the combustor 52 . In some embodiments, the swirler 60 forms a sealing engagement at the flange 150 with the recuperator 50 . However, other constructions employ a swirler head that is formed as part of the combustor 52 . In still other constructions, the swirler 60 is a separate component positioned away from the remainder of the combustor 52 .
[0035] The outer chamber 139 is an annular chamber within the body 135 of the swirler 60 . A fuel inlet 165 can be coupled to the outer side 155 of the body 135 in fluid communication with the outer chamber 139 to deliver fuel into the outer chamber 139 . A plurality of bores between the outer chamber 139 and the inner side 160 of the swirler 60 permit fuel in the outer chamber 139 to flow through the swirler 60 into the prechamber 64 . Guide tubes 169 extending from the inner side 160 of the swirler 60 adjacent to the bores guide the flow of fuel into the prechamber 64 .
[0036] The inner chamber 137 is disposed radially inwardly of the outer chamber 139 . A pilot fuel inlet 175 can be coupled to the outer side 155 of the body 135 in fluid communication with the inner chamber 137 to deliver pilot fuel into the inner chamber 137 . A plurality of bores 177 between the inner chamber 137 and the inner side 160 of the swirler 60 permit pilot fuel in the inner chamber 137 to flow through the swirler 60 into the prechamber 64 . The pilot fuel inlet 175 provides a flow of fuel through the swirler 60 that may be used to maintain the flame stability within the combustor 52 at low power settings or to initiate combustion within the combustor 52 during engine start.
[0037] Also visible on the outer side 155 of the swirler 60 is a hole 190 in the swirler 60 for receiving an ignition device 195 . The ignition device 195 provides a flame, spark, hot surface or other ignition source to initiate combustion during engine start-up or at any other time when a flame is desired but not present.
[0038] The flow guides 145 are generally raised triangular blocks on the inner side 160 of the body 135 . Each flow guide 145 has two planar surfaces 180 and an arcuate outer surface 183 . The planar surfaces 180 of each flow guide 145 are arranged such that they are substantially parallel to the planar surfaces 180 of the adjacent flow guides 145 . Using this arrangement, a plurality of flow paths 185 are defined between adjacent flow guides 145 extending inwardly. The flow paths 185 are oriented to inject the premixed fuel and air into the prechamber 64 with a high degree of swirl about a centerline or central axis A (see FIG. 5 ) of the cylindrical prechamber 64 . Many different arrangements are possible to direct fuel and air into the prechamber 64 . As such, the invention should not be limited to the aforementioned example.
[0039] The flow guides 145 are disposed radially between the inner chamber 137 and the outer chamber 139 . Thus, the guide tubes 169 communicating with the outer chamber 139 are located at an outer end or entrance 186 of the flow paths 185 and the bores 177 communicating with the inner chamber 137 are located at an inner end or exit 187 of the flow paths 185 (see FIG. 6A ). Referring now to FIG. 6B , an annular combustor flange 153 is mounted to flow guides 145 with fasteners (not shown) at aligned openings 154 a , 154 b . The combustor flange 153 partially encloses the flow paths 185 to facilitate the flow of air and fuel from the entrances 186 to the exits 187 . The combustor flange 153 can also be secured to the combustor 52 to facilitate securing the swirler 60 to the combustor 52 .
[0040] By injecting the fuel at the entrance 186 to the flow path 185 , the fuel and air have adequate time to thoroughly mix prior to exiting the flow path 185 at the exit 187 . This uniform mixture of F/A reduces the likelihood of fuel-rich burning in combustion chamber 66 , which could lead to high levels of NOx. In other embodiments, fuel could be injected at a plurality of other locations also, so as to ensure the F/A mixture leaving the flow paths 185 uniformly mixed.
[0041] The hole 190 for the ignition device 195 is located between the centerline A of the prechamber 64 and an inside “diameter” defined by the flow path exits 187 . The ignition device 195 can ignite the premixed F/A exiting the flow paths 185 and can ignite the pilot fuel exiting the holes 177 , but is not subjected to and/or is less subjected to the high temperatures of an inner recirculation zone 86 (see discussion below with regard to FIG. 5 ).
[0042] As shown in FIG. 5 , premixed F/A is injected into the prechamber 64 with a swirling flow path or directionality under the influence of the action of the swirler 60 , as indicated by arrow 80 . Other structures may be provided to impart a swirl to the F/A mixture and introduce it to the prechamber 64 . The swirling F/A mixture 80 is conveyed in a downstream direction through the prechamber 64 and exits the prechamber 64 into the combustion chamber 66 . This axial motion is combined with a swirling motion about the centerline axis A of the combustion chamber 66 , producing a vortex, indicated by arrow 82 . This vortex 82 creates a pressure difference between the center of the vortex 82 , located at the centerline A, and the inner perimeter of the prechamber 64 . The centerline of the vortex 82 is at a lower pressure than the outside edge of the vortex 82 , similar to the low pressure experienced at the center of a hurricane.
[0043] The flow area in the combustion chamber 66 has a larger cross-sectional area than the flow area in the prechamber 64 (i.e., the combustion chamber 66 has a greater inner diameter than the prechamber 64 ). When the axially processing vortex 82 enters the combustion chamber 66 , the increase in flow area causes the vortex 82 to expand radially and slow its axial and rotational or swirling movement, as indicated by arrow 84 . The expanded vortex 84 has a reduced pressure difference between the outside edge of the vortex 84 and the center. Thus, the centerline A of the prechamber 64 at the vortex 82 is at a lower pressure than the centerline of the combustion chamber 66 at the vortex 84 . An inner recirculation flow, as indicated by arrow 86 , is established which pulls a portion of the gases from the combustion chamber 66 back into the prechamber 64 in an upstream direction, i.e., from right to left. This process is referred to herein as a “vortex breakdown” structure and stabilizes the flame in the combustion chamber 66 .
[0044] The F/A mixture conveyed from the prechamber 64 to the combustion chamber 66 chemically reacts in a combustion flame. The products of combustion are hotter than the reactants introduced into the prechamber 64 (i.e., the premixed F/A at flow 80 ). The inner recirculation flow 86 therefore is composed of hot products of combustion. The inner recirculation flow 86 is directionally opposed to the unburned F/A mixture of vortex 82 , and an inner shear layer is established between the two. Hot gas products and combustion radicals in the recirculation flow 86 , which are unstable electrically-charged molecules like OH—, O—, and CH+ are exchanged with the unburned F/A of vortex flow 82 . Recirculation flow 86 serves as a continued ignition source for vortex flow 82 . The chemical radicals also enhance the reactivity of the unburned mixture of vortex flow 82 , enabling the F/A mixture of vortex flow 82 to extinguish combustion at a lower F/A ratio than if vortex flow 82 did not have the radicals from recirculation flow 86 .
[0045] FIGS. 8 and 9 illustrate the cooling assembly 200 . Air, including recuperated air, can be injected through the cooling assembly 200 into the prechamber 64 . The cooling assembly 200 is provided to reduce any temperature differential across the inner surface 160 of the swirler 60 that may be generated by the hot recirculation flow 86 at the centerline A.
[0046] The cooling assembly 200 resides in a channel 202 extending through the swirler 60 at the centerline A. In general, the channel 202 and the cooling assembly define a central axis that is co-linear with the central axis A of the prechamber 64 . The channel 202 has sloped sides, so that a channel opening 203 on the inner side 160 is larger than a channel opening 204 on the outer side 155 (see FIGS. 8-9 ). The outer channel opening 204 can be coupled to an air inlet 205 so that the channel 202 is in fluid communication with a source of cooling air. In the illustrated embodiment, the air inlet 205 receives air from the recuperator 50 . Specifically, the air inlet 205 is coupled to an opening 151 in the flange 150 that is in fluid communication with the recuperator 52 (see FIG. 8 ). However, any source of air that is cooler than the recirculation flow 86 will suffice.
[0047] As shown in FIGS. 8-11 , the cooling assembly 200 includes a distributor ring 206 and a perforated shield 210 . The distributor ring 206 is located within the channel 202 downstream of the air inlet 205 . The ring 206 includes a plurality of apertures 207 for receiving air therethrough from the air inlet 205 . In some embodiments, the apertures 207 are angled outwardly to direct air flowing therethrough uniformly onto the shield 210 .
[0048] Downstream of the distributor ring 206 , the shield 210 covers the inner opening 203 of the channel 202 (see FIGS. 8-9 ). The shield 210 includes a plurality of apertures 214 for permitting air flow through the shield 210 . In the illustrated embodiment, the apertures 214 are in the form of nozzles. In some embodiments, the shield 210 is approximately flush with the inner side 160 of the swirler 60 .
[0049] The shield 210 includes a sleeve 216 for threadedly coupling the shield 210 to the distributor ring 206 . A portion of the swirler body 135 adjacent to the channel 202 is clamped between the shield 210 and the distributor ring 206 to secure the cooling assembly 200 to the swirler 60 . This arrangement permits some expansion and contraction of the shield 210 relative to the swirler 60 . In other embodiments (not shown), the distributor ring 206 is snap-fit, bolted, adhesively bonded or otherwise coupled to the shield 210 . In other embodiments (not shown), the shield 210 and/or the distributor ring 206 are coupled to the swirler 60 through a threaded coupling or a snap-fit coupling at the channel 202 , can be bolted to the swirler 60 , and can be adhesively coupled to the swirler 60 . In still other embodiments, all or a portion of the cooling assembly 200 is integrally formed with the swirler 60 .
[0050] Air from the cooling air inlet 205 flows through the apertures 207 in the distributor ring 206 into the channel 202 . Heat is conducted from the swirler 60 to the cooling assembly 200 while still within the channel 202 , then transferred by convection to the air flowing through the channel 202 . The air flowing through the channel 202 flows through the apertures 214 in the shield 210 and into the prechamber, generating a cooling flow, indicated at arrow 212 . The heat transferred from the swirler to the cooling assembly 200 is removed from the swirler 60 as the cooling flow 212 exits the channel 202 and flows into the prechamber 64 . This can facilitate reducing the temperature of the swirler 60 adjacent to the cooling assembly 200 and of the cooling assembly 200 itself.
[0051] Referring to FIG. 9 , the cooling flow 212 flows opposite to and meets with the recirculation flow 86 to generate a stagnation plane, indicated at 218 , between the swirler inner side 160 and the recirculation flow 86 (see also FIG. 5 ). The cooling flow 212 as well as the stagnation plane 218 form an air layer separating the swirler inner side 160 from the hot recirculation flow 86 . This air layer provides a thermal barrier to heat transfer from the recirculation flow 86 to the swirler 60 . Any heat transfer from the recirculation flow 86 to the swirler 60 passes through the air layer via conduction rather than convection.
[0052] The cooling assembly 200 can be formed of a different material than the swirler 60 . For example, the cooling assembly 210 can be formed of one or more materials having a different resistance to thermal transfer and/or coefficient of thermal expansion than the material of the swirler 60 . In other embodiments, all or a portion of the cooling assembly 200 is formed of the same material(s) as the swirler 60 .
[0053] The cooling assembly 200 inhibits the forming of a “hot spot” on the swirler inner side 160 at the centerline A due to impingement of the hot recirculation zone 86 . This provides for a more radially uniform swirler temperature during use. Radial temperature uniformity can reduce nonuniform thermal stresses on the swirler 60 (such as, for example, increased thermal expansion at the centerline A in relation to thermal expansion closer to the flange 150 ), thereby increasing the life of the swirler 60 . In addition, the cooling assembly 200 can be formed of a material that has a greater resistance to thermal expansion than the remainder of the swirler 60 , regardless of the operation of the cooling flow 212 . Furthermore, the cooling assembly 200 can be formed separately from the swirler 60 , so that some or all of the thermal stresses on the cooling assembly 200 are not mechanically transferred to the remainder of the swirler 60 . For example, the cooling assembly 200 can be allowed to undergo thermal expansion and contraction separately from the remainder of the swirler 60 .
[0054] In addition to a single can combustor, can-annular combustor arrangements are commonly used, where multiple single combustor cans are oriented upstream of an annular combustor liner. Transition hardware is used to convey the combustion gases from the individual cans to the annular portion of the combustor. The annular portion of the combustor then conveys hot gases to a turbine, typically with the use of turbine nozzles or turbine vanes. The invention disclosed herein is applicable to can-annular combustors, applying to the upstream portion where fuel and air are injected and flow stabilization occurs.
[0055] Thus, the invention provides, among other things, a method and apparatus to inhibit circumferentially non-uniform thermal stresses on the swirler surface. Various features and advantages of the invention are set forth in the following claims.
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A combustor for a gas turbine engine is disclosed which is able to operate with high combustion efficiency, and low nitrous oxide emissions during gas turbine operations. The combustor consists of a can-type configuration which combusts fuel premixed with air and delivers the hot gases to a turbine. Fuel is premixed with air through a swirler and is delivered to the combustor with a high degree of swirl motion about a central axis. This swirling mixture of reactants is conveyed downstream through a flow path that expands; the mixture reacts, and establishes an upstream central recirculation flow along the central axis. A cooling assembly is located on the swirler co-linear with the central axis in which cooler air is conveyed into the prechamber between the recirculation flow and the swirler surface.
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BACKGROUND OF THE INVENTION
This invention relates to a method and system for determining certain characteristics of porous material taken from subsurface formations and, more particularly, to a method and system for determining permeability of a core sample taken from a subsurface hydrocarbon-bearing reservoir by measuring the fluid volumes of a two-phase effluent fluid flow through the core sample.
In the production of an oil or gas reservoir, it is important to know certain lithological properties of the reservoir. One of the most important of these properties is the permeability of the reservoir rock in which the oil or gas is stored. Permeability is a measure of the ability of the reservoir rock to transmit fluids through pore spaces in the porous rock material and is inversely proportional to the flow resistance offered by the material. A core sample of a subsurface rock material is generally tested for permeability by forcing a fluid through the core sample, which has been previously saturated with the same fluid, and measuring the rate of flow of the fluid through the core sample.
SUMMARY OF THE INVENTION
The present invention is directed to a new method and system for determining fluid volumes of a two-phase effluent fluid flow through a porous material so that the permeability characteristic of the porous material may be determined. A two-phase fluid flow condition is established through the porous material, such as a core sample taken from a subsurface hydrocarbon-bearing reservoir. One phase is a liquid hydrocarbon phase, and the other phase is an insoluble displacing liquid phase. After exiting the core sample, the two-phase fluid is collected in a container where it separates into an overlying fluid phase (e.g., oil) and an underlying fluid phase (e.g., water). A fluid level monitor is positioned in the container. When the air-fluid interface of the top of the overlying fluid phase rises to a first position in the upper portion of the container, drainage of the underlying fluid phase from the container is initiated. The time is measured during which the fluid-fluid interface between the overlying and underlying fluid phases is lowered to a second position near the bottom of the container. The time is also measured during which the air-water interface of the top of the overlying fluid phase is lowered to the same second position near the bottom of the container. The volumes of each of the two fluid phases are determinable from the two time measurements and the drainage flow rate of the fluid, such volumes being representative of the fluid saturation in the core sample, from which core sample permeability is determined.
In a further aspect of the invention, changes in capacitance between such first and second positions within the container are used to identify the locations of the two fluid phases. This capacitance is measured between electrical conductors at such first and second positions with the changing of the air-fluid and fluid-fluid interfaces acting as a changing dielectric between the electrical conductors.
In another aspect of the invention, changes in fluid density between such first and second positions with the container are used to identify the locations of the two fluid phases. Such density changes are measured by fluid density cells located at such first and second positions.
BRIEF DESCRIPTION OF THE DRAWING
The drawing illustrates a system for carrying out the fluid volume determination of a two-phase effluent fluid flow through a porous material of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, there is disclosed a system for carrying out the method of the present invention. A core sample 10 of a porous material is taken from a subsurface formation. This core sample is initially saturated with a liquid hydrocarbon, such as oil; an insoluble displacing fluid, such as water; or brine; or a combination thereof. Thereafter, a two-phase effluent fluid flow is established through the core sample by the continuous injection of oil, water, or a combination thereof into the core sample through channel 11. This two-phase effluent fluid flow out of core sample 10 is carried by way of channel 12 into the upper portion of a fluid container 13. A drainage channel 14 leads from the lower portion of container 13. This drainage channel is initially closed by the valve 15. As the two-phase effluent fluid is collected in the container 13, it separates into an overlying liquid hydrocarbon phase (i.e., oil) and an underlying insoluble displacing fluid phase (i.e., water) 21. As such fluid is collected and later drained therefrom as described hereinbelow, a liquid level monitor 16 continually detects the position within the container 13 of both the air-fluid interface 22 at the top of the overlying oil phase and the fluid-fluid interface 23 between the overlying oil phase and the underlying water phase.
In one embodiment of the invention, liquid level monitor 16 measures the capacitance between a pair of electrodes 24 and 25 which pass through the container by means of feed through terminals 26 and 27, respectively, and are located at spaced-apart vertical positions within the container 13. The lower electrode 24 needs to be located near the bottom of the container 13 so that an accurate determination can be made of the completion of the drainage on the two fluid phases. The underlying and overlying fluid phases 21 and 20, respectively, along with the air space above overlying fluid phase 20 form the dielectric between the two electrodes 24 and 25 in a capacitance-type liquid level measuring system.
With the valve 15 in a closed position, the two-phase effluent flow from core sample 10 begins to fill the container 13, the two phases separating in the process. When the air-fluid interface at the top of the overlying fluid phase rises so as to make contact with electrode 25, a distinct capacitance change is noted across the electrodes 24 and 25. This new capacitance is converted into a proportional voltage signal by the liquid level monitor 16 for use in the activation of a relay 30. In turn, relay 30 activates a counter 31 and opens valve 15 to initiate drainage of the underlying fluid phase 21 from container 13. Relay 30 also operates valve 32 to cause the drainage of the underlying fluid phase to be collected in the container 33. The flow rate meter 34 detects the rate at which such underlying fluid phase is drained from container 13.
As the fluid level in container 13 lowers, the fluid-fluid interface 23 contacts electrode 24 near the bottom of container 13. A capacitance change is again detected by the liquid level monitor 16, thereby indicating that the underlying fluid phase 21 has been drained from container 13. At this time, the liquid level monitor 16 activates relay 35. In turn, relay 35 activates counter 36 and changes the position of valve 32 to initiate drainage of the overlying fluid phase into container 37. Also at this time, counter 31 may continue to run along with counter 36, or it may be inactivated by liquid level monitor 16 and relay 30. Should counter 31 be inactivated, the recorded count will represent the time required for the underlying fluid phase to be drained from container 13. Should counter 31 not be inactivated at this time, it will continue to run, along with counter 36, until the air-fluid interface 22 of the top of the overlying fluid phase makes contact with electrode 24. At this time, liquid level monitor 16 again detects a change in capacitance across electrodes 24 and 25. In turn, liquid level monitor 16 inactivates counter 36 and, likewise, counter 31 if it had not been inactivated earlier in time as described above. Also, valve 15 is closed and valve 32 is returned to its original position. The recorded count in counter 36 represents the time required for the overlying fluid phase 20 to be drained from container 13. If counter 31 had not been inactivated earlier, it now represents the time for both fluid phases to be drained from the container 13. Accordingly, the difference in the counts of counter 31 and 36 represent the time for the underlying fluid phase 21 to be drained from container 13.
In a yet further alternative, both counters 31 and 36 may be activated by the air-fluid interface 22 reaching the electrode 25, counter 31 may be inactivated when the fluid-fluid interface 23 reaches electrode 25, and counter 36 may be inactivated when the air-fluid interface 22 reaches electrode 24. In this alternative, the count in counter 31 represents the time for drainage of the underlying fluid phase 21, while the difference in the counts of the counters 31 and 36 represent the time for drainage of the overlying fluid phase 20.
Upon completion of the drainage process of both phases of the fluid in container 13, and the closure of valve 15 and switching of valve 32, the refilling and subsequent drainage of container 13 can be repeated as needed so long as the drainage flow rate of the fluid out of container 13 significantly exceeds the effluent flow rate of the fluid out of core sample 10. Typical core effluent flow rate is in the range of 5 to 100 cubic centimeters per hour. Typical drainage rate from container 13 is greater than 100 cubic centimeters per minute.
In carrying out the above-described method, a particularly suitable flow cell assembly for holding core sample 10 so as to allow the two-phase effluent flow is shown in detail in U.S. Pat. No. 4,531,404 to Phelps and Sampath, the contents of which are incorporated herein by reference. Another suitable flow cell assembly reference is U.S. Pat. No. 2,345,935 to Hassler. A suitable capacitance-type liquid level monitor 16 includes a capacitance-to-frequency converter and a frequency-to-voltage converter, such as shown in detail in U.S. Pat. No. 4,381,665 to Levine and Marek, the contents of which are also incorporated herein by reference. As an alternative to the capacitance-type liquid level monitor, one of several conventional liquid level detecting devices might be utilized including a device, such as the densimeter cell, for detecting fluid density changes as the various fluid interfaces pass the location of the density cell. One such densimeter cell is the Mettler/Paar DMA 512. A suitable flow rate meter 34 is the Rheotherm meter supplied by Intek, Inc. or the Omniflo meter supplied by Flow Technology, Inc.
While a particular embodiment of the present invention has been shown and described, other modifications may be within the true scope and spirit of the invention. The appended claims are, therefore, intended to cover such modifications.
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A liquid hydrocarbon and an insoluble displacing fluid are passed through a core sample from a subsurface formation. The two-phase effluent flow out of the core sample is collected in a container where the two phases separate into an overlying fluid phase and an underlying fluid phase and the volumes of each phase are measured as an indication of the permeability of the core sample. Such volumes are measured by placing fluid level detectors in the container and detecting the movements of the air-fluid interface of the top of the overlying fluid phase and the fluid-fluid interface between the two phases as the fluid is drained from the container.
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BACKGROUND OF THE INVENTION
This invention relates to the cutting of materials, and, more particularly, to the facilitation of cutting operations.
Cutting operations can be effected in many ways. One of the most useful incorporates a chain saw, in which a motor driven chain with cutting elements rotates about an elongated support known as a cutter bar.
In the use of the chain saw, the cutter bar is brought into contact with the materials to be cut. Unfortunately, the chain saw can be unwieldy and difficult to use with such materials as brush and the branches of trees. Even where the cutting operations is comparatively simple, special care must be taken to guard against accidents.
Accordingly, it is an object of the invention to facilitate cutting operations. A related object is to facilitate such operations using a chain saw.
Another object of the invention is to guard against accidents in the use of cutting instrumentalities such as chain saws. A related object is to avoid the need for unbalanced and unwieldy movements in the use of cutting instrumentalities such as chain saws.
Being a motor driven device, with a two-cycle engine, it is often comparatively difficulty to start. Typical starting instructions require two handed operation. One hand grips the handle and the other pulls on the starting cord. As a result the chain saw is in unstable equilibrium and there is a possibility of unbalanced movement of the saw and consequent accidental cutting.
Accordingly, it is another object of the invention to facilitate the starting of motor driven cutting instrumentalities such as chain saws. A related object is to promote safe starting.
SUMMARY OF THE INVENTION
In accomplishing the foregoing and related objects, the invention provides for facilitating the operation of a cutting instrumentality, such as a chain saw, by pivotally supporting the instrumentality and securing the support to a mount with the cutting instrumentality supported below the upper level of the mount.
In accordance with one aspect of the invention, the pivotal support includes a spindle for supporting the cutting instrumentality below the upper level of the mount. Provision is also made where necessary to adapt the cutting instrumentality to be received by the spindle. In the case of a conventional chain saw, this can be achieved by incorporating a cylindrical sleeve below the base surface of the saw, extending from a lower previously applied chain saw connector to the base position of the conventional side handle commonly found in chain saws. The lower connector is a conventional machine screw that is used to affix a guard shield on the saw at the motor drive position for the saw blade. The other end of the cylinder is attached to the base portion of the side handle by a wing that projects outwardly from the cylinder.
In accordance with another aspect of the invention, the support member is in the form of a flange with a first section for connection to the mount and a second section extending from the first section and containing the spindle which is used to receive the cutting instrumentality. The second section extends at an angle with respect to the first section which is desirably greater than 90°.
In accordance with a further aspect of the invention, the second section includes a backstop beyond the position of the spindle to provide temporary support for the chain saw. A pivoted lever on the backstop can be used for securing the chain saw on the support with respect to its spindle.
In use of the support, the chain saw with its adaptor, such as a base mounted cylindrical sleeve, is positioned on the spindle using the sleeve, the retention lever on the backstop is pivoted to secure the chain saw on the sleeve and the saw is started. Because of the stability imparted by the mount supported spindle, the starting operation is simply a matter of pulling on the starting cord while the other hand holds the saw against the backstop of the support. Once the saw is started it is easily used by simply pivoting the saw about the spindle with the items to be cut fed into the cutting path. Where the mount for the support is a bench, the feeding operation merely involves moving the items to be cut along the top surface of the bench to the cutting position.
DESCRIPTION OF THE DRAWINGS
Other aspects of the invention will become apparent after considering several illustrative embodiments taken in conjunction with the drawings in which:
FIG. 1 is an overall view showing a chain saw adapted for cutting and starting in accordance with the invention;
FIG. 2 is a perspective view of a support on a mount for the chain saw of FIG. 1;
FIG. 3 is a bottom view of the chain saw of FIG. 1 showing an adaptor for accommodating the saw to the support of FIG. 2; and
FIG. 4 is an overview showing the system of FIG. 1 in use.
DETAILED DESCRIPTION
With respect to the drawings, FIG. 1 shows a system 10 for facilitating the operation of a chain saw 20 in accordance with the invention. The chain saw 20 is pivotally positioned on a support 30 which is in turn secured to a mount 40.
In FIG. 1 the mount 40 is a bench with legs 41 and 42 that support the upper surface 43 of the mount 40 at a convenient height. Near one end of the support surface 43 the support member 30 is secured by conventional fasteners. The exact position of the support 30 on the mount surface 43 depends upon the chain saw 20 and is sufficient to permit the bar 21 of the saw 20 to clear the end 44 of the mount 40. Additional security is provided by a shield 45 at the edge of the mount 40 nearest the user. In addition the shield 45 increases the firmness with which the support 30 is held to the surface 43. It will be understood that the shield may be extended upwardly to any convenient height to provide additional security and guidance for objects fed along the surface 43 for cutting.
Details of the support 30 are shown in FIG. 2. The support 30 is in two sections 31 and 32. The first section 31 is generally horizontal and has an end which projects outwardly from beyond the shield 45. At the end of the projection, the second section 32 is integrally secured at a bend 33. The second member 32 includes a spindle 34 below the bend 33 and a support 35 at the end of the section 32. The spindle 34 is adapted for receipt of the chain saw which can be modified as explained below. The support 35 provides a temporary backrest so that when the chain saw 20 is unattended, it adopts the position shown in FIG. 1.
The backrest 35, as seen in FIG. 2, includes a cushion 35c in the form of a cylinder and a retainer 35r, in the form of a pivoted handle. After the chain saw 20 is placed on the spindle 34, the retainer 35r is pivoted upwardly to prevent accidental dislodgement of the saw from the spindle. The retainer 35r is secured to the backrest arm 35 in any convenient way.
One adaptation of the chain saw 20 for positioning on the spindle 34 is shown in FIG. 3. A mounting sleeve 50 has one end 51 secured by the fitting 23 that normally holds the guard cover 24 at the motor drive position for the chain 22. The sleeve 50 is conveniently threaded on the fitting 23. The other end 52 of the sleeve 50 includes a tab 53 that extends outwardly from the sleeve 50. The tab may be secured to the sleeve 50 by conventional welding. The tab 53 is inserted below the connection point 24 of the side handle 25.
Using the sleeve 50 the saw 20 is readily fitted onto the support 30 at the spindle 34, adopting the position shown in FIG. 1. It will be apparent that with the saw 20 in this position it can be conveniently started. Once started, the saw 20 can be used as shown in FIG. 4 by pivoting the saw 20 to bring the rotating chain 22 into contact with the work piece 47.
While various aspects of the invention have been set forth by the drawings and specification, it is to be understood that the foregoing detailed description is for illustration only and that various changes in parts, as well as the substitution of equivalent constituents for those shown and described may be made without departing from the spirit and scope of the invention as set forth in the appended claims.
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A device for cutting logs which involves swinging a chain saw about a fixed pivot to bring the chain of the saw into cutting engagement with a log while the log is supported in elevated position the apparatus includes a table having a log supporting top, and a pivoted mounting plate for the chain saw.
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FIELD OF THE INVENTION
[0001] The invention relates to waterborne adhesive compositions. The compositions of the invention have properties that make them particularly well suited for use in bonding to fire retardant treated wood and wood composites.
BACKGROUND OF THE INVENTION
[0002] Wood and wood composites, in particular when used in the manufacture of articles to be used in public places, such as in office buildings, schools, hospitals and the like, are typically treated with certain fire retardant chemicals to make them more fire resistant. Among various fire retardant chemicals, boron compounds, are often used since they are low in cost and mammalian toxicity, and have a minimum environmental impact. When fire resistant articles are manufactured using conventional wood adhesives, the adhesive will gel upon contact with wood and wood composites that have been treated with fire retardants. The fire retardant chemicals in the wood and wood composites crosslink the adhesive and form a rubbery precipitate, resulting in a poor, weak bond at the interface. Such conventional used wood adhesives are manufactured using resin emulsions stabilized with polyvinyl alcohol. While neoprene-based contact cements have, alternatively, been used as a wood adhesive, these types of adhesives are difficult to use since the wood must first be sanded to open the pores, at least double the amount of adhesive is required to be used, and heat must be applied in order to form the bond.
[0003] There continues to be a need in the art for wood adhesives that can form a good bond with wood and wood composites that have been treated with fire retardant compounds. The current invention addresses this need.
SUMMARY OF THE INVENTION
[0004] The invention provides waterborne adhesive compositions having good adhesion properties to fire retardant treated wood and wood composites.
[0005] One embodiment of the invention is directed to a waterborne adhesive comprising at least one resin emulsion such as a polyvinyl acetate and/or an ethylene vinyl acetate emulsion stabilized by dextrin and/or surfactant. In one embodiment, the resin emulsion is dextrin stabilized polyvinyl acetate. In another embodiment, the resin emulsion is both dextrin and surfactant stabilized polyvinyl acetate. The adhesive may desirably also comprises at least one filler and may, optionally, further comprise a phenolic resin, defoamer, rheology modifier, surfactant and/or other conventional additive.
[0006] Another embodiment of the invention is directed to a method for bonding fire retardant treated wood or wood composite substrate to a similarly treated wood or wood composite substrate or to a dissimilar substrate. The method comprises applying the adhesive composition of the invention to a first substrate, bringing a second substrate in contact with the composition applied to the first substrate, and subjecting the applied composition to conditions which will allow the composition to dry and cure. In one embodiment, both the first and the second substrate is a fire retardant treated wood or wood composite.
[0007] Yet another embodiment of the invention is directed to articles manufactured using the adhesive composition of the invention. Articles of the invention will comprise at least one substrate that is a wood or wood composite treated to give it fire retardant properties. Encompassed articles include, but are not limited to, elevator cabs, kiosks, passenger boarding bridges, architectural woodwork, wall sheathing, wainscoting, display panels, door components, furniture including classroom and office furniture such as desks and bookshelves, fixtures, commercial case goods, shelving, cabinets, countertops, and the like. The manufactured fire retardant articles are well suited for use in public places where large number of people assemble, e.g. offices, schools, hospitals, and the like.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The term “waterborne adhesive” refers to an adhesive composition, the components of which are carried in an aqueous medium. The waterborne adhesives of the invention comprise at least one resin emulsion, i.e., a resin that has been suspended or dispersed in water As the water evaporates, the adhesive hardens and adheres to the substrate.
[0009] As used herein, the terms “fire retardant substrate” and “fire retandant treated substrate” refer to wood and wood composites that have been treated to increase its resistance to fire and include Borax treated wood and wood composites. “Wood composites” encompass, for example, wood veneers, high-pressure laminants, chipboard, particleboard, medium density fiberboard, high density fiberboard, oriented strandboard, hardboard, hardwood plywood, veneer core plywood, isocyanate or phenolic impregnated strawboard, and wood composites made from wood fiber and polymers, such as recycled polyethylene.
[0010] It has been discovered that certain types of waterborne adhesives, when used as a wood adhesive, strongly adheres to and can be used to bond together substrates (wood and wood composites) treated with substance, such as Borax, to increase fire retardancy.
[0011] Hereinafter, fire retardant treated wood and wood composites will be referred to, in the alternative, as “fire retardant substrate” or “fire retandant treated substrate” Resin emulsions which may be used in the practice of the invention are polyvinyl acetate, ethylene vinyl acetate or various blends thereof. In one embodiment a blend of two or more polyvinyl acetate emulsions are used. The resins used to prepare the emulsions will generally have a glass transition temperature from about −15° C. to about 40° C., more typically from about −5° C. to about 30° C. The resin emulsion used in the practice of the invention are those that are stabilized with dextrin, surfactant, or a mixture thereof. Dextrin stabilized, surfactant stabilized, and dextrin and surfactant stabilized resin emulsions are useful in the practice of the invention.
[0012] Surfactants that can be used to stabilized resins in the preparation of emulsions used in the practice of the invention include, but not limited to, alkyl sulfonates, alkylaryl sulfonates, alkyl sulfates, sulfates of hydroxylalkanols, alkyl and alkylaryl disulfonates, sulfonated fatty acids, sulfates and phosphates of polyethoxylated alkanols and alkylphenols, esters of sulfosuccinic acid, alkyl quaternary ammonium salts, alkyl quaternary phosphonium salts, ethylene oxide adducted to straight-chain and branched-chain alkanols having 6 to 22 carbon atoms, alkylphenols, higher fatty acids, higher fatty acid amines, primary or secondary higher alkyl amines, and block copolymers of propylene oxide with ethylene oxide, and mixtures thereof.
[0013] The amount of dextrin and/or surfactant used to stabilize polyvinyl acetate and ethylene vinyl acetates range from about 0.05 to 10 dry weight percent, preferably 0.2 to about 6 dry weight percent, based on the total emulsion, in the practice of the invention.
[0014] While the solids content of the resin emulsion is not particularly limiting to the practice of the invention, high solids resin emulsions, particularly from about 50 to about 70% solids in water (w/w) are typically preferred for used in the practice of the invention
[0015] Dextrin-stabilized polyvinyl acetates are commercially available from Celanese, under the trade name Resyn®1072.
[0016] It has been found that adhesives comprising the stabilized resin emulsions of the invention can be used as a wood adhesive to form a strong bond with fire retardant treated substrates.
[0017] The adhesive may also contain a filler. The addition of a filler controls the rheology of the adhesive. Suitable fillers known and used in the adhesive arts include polysaccharides, calcium carbonate, clay, mica, nut shell flours, silica, talc and wood flour.
[0018] One preferred filler is a polysaccharide. Polysaccharides useful in the invention include starch, dextrin, cellulose, gums or combinations thereof. Particularly useful are the starches and dextrin including native, converted or derivatized. Such starches include those derived from any plant source including maize (corn), potato, wheat, rice, sago, tapioca, waxy maize, sorghum and high amylose starch such as high amylose corn, i.e. starch having at least 45% amylose content by weight. Starch flours may also be used. Also included are the conversion products derived from any of the former bases, such as, for example, dextrin prepared by hydrolytic action of acid and/or heat; fluidity or thin boiling starches prepared by enzyme conversion or mild acid hydrolysis; oxidized starches prepared by treatment with oxidants such as sodium hypochlorite; and derivatized or modified starches such as cationic, anionic, amphoteric, non-ionic, crosslinked and hydroxypropyl starches. Other useful polysaccharides are cellulose materials such as carboxymethylcellulose, hydroxypropyl cellulose and hydroxypropyl methylcellulose, and gums such as guar, xanthan, pectin and carrageenan may also be used in the practice of the invention. Modified starches include, but are not limited to, those modified with an alkyl succinic anhydride. Preferred are octenyl succinic anhydride (OSA) and dodecenyl succinic anhydride (DDSA) modified starches or dextrin.
[0019] The adhesive may further optionally include a phenolic resin. The use of phenolic resin in the adhesive composition enhances water resistance of the cured adhesive. Particularly preferred phenolic resins include those resins that give off low or no volatile products upon curing and do not involve the use of formaldehyde or formaldehyde-producing agents in their preparation. The use of formaldehyde introduces environmental and toxicological problems in the preparation, fabrication, and even in the long term use of such materials. These are points of attack for high temperature oxidative degradation. Exemplary phenolic resin includes Arofene® 72155-W55 available from Ashland Chemicals, Schenectady SP-103, SP103H, SP-12, SP-134, SP-134H, SP-154, SP-154H, SP-184, SP-274 and SP-8219 available from Schenectady Chemical.
[0020] In addition to fillers, other additives typical of adhesive compositions may be added to the composition. Said additives include, but are not limited to, defoamers, thickeners, rheology modifiers, plasticizers, acids, waxes, synthetic resins, tackifiers, preservatives, bases such as sodium hydroxide, dyes, pigments, UV indicators, surface-active agents (anionic, cationic, amphoteric, or nonionic surfactants) and other additives commonly used in the art.
[0021] Adhesive composition of the invention will generally comprise, by weight, about 85.0% to about 99.0% dextrin, surfactant or dextrin and surfactant stabilized resin emulsion, about 0.1% to about 10% filler, up to about 5% phenolic resin, and up to about 5% other types of conventional additives. The cured adhesive composition will comprise about 50.0% to about 99.0%, more typically from about 70.0% by to about 97.0% by dry weight of the resin emulsion (without water), and from 0.1% by weight to about 10.0% by dry weight of filler (without water).
[0022] The adhesive may be applied by any method known in the art. Typically one substrate is coated with adhesive. A second substrate is placed atop of the adhesive with pressure to bond the substrates together. At least one substrate is a fire retardant treated substrate. The adhesive is used to bond the fire retardant treated substrate to a similarly treated substrate or to another substrate, such as medium density fiberboard or high pressure laminate. In one embodiment the first and the second substrate are both fire retardant treated substrates. Pressure may be applied to the construction by any suitable means. Typical bonding pressure is about 50 psi, although higher pressure is possible. Preferably, pressure is applied via a roller during a cold or hot press process.
[0023] Heat may also be introduced by means of heating elements, or by heating rollers. The use of heat decreases the overall time to bond the substrates together.
[0024] The method of the present invention can be advantageously utilized in the manufacture of elevator cabs, kiosks, passenger boarding bridges, architectural woodwork, wall sheathing, wainscoting, display panels, door components, furniture (desks, chairs, etc.), fixtures, commercial case goods, shelving, cabinets, countertops, and the like.
[0025] The invention is further illustrated by the following non-limiting examples.
EXAMPLES
[0026]
[0000]
TABLE 1
Components
(g)
Dextrin stabilized polyvinyl acetate
950
(Resyn ® 1072, Celanese)
(63% solids content in water)
Filler (Dextrin, National Starch)
30
Phenolic resin (Arofene 72155-W55,
20
Ashland Chemical Company)
Defoamer (Nopco NXZ, Nopco Paper Technology)
10
[0027] The adhesive was prepared by combining all of the components in Table 1 and mixing at room temperature with stirring for about 30 minutes.
Cold Press
[0028] A bondline thickness of about 6 mils of the above adhesive composition was applied on a 3″×3″ medium density fiberboard (MDF). A wood veneer, also 3″×3″ was applied on top of the adhesive. Both the MDF and the wood veneer had been treated with Borax. A pressure of 50 psi was applied on top of the veneer for 30 minutes at room temperature. No gelling or other precipitation of the applied adhesive was observed. The MDF and wood veneer were strongly bonded together.
Hot Press
[0029] A bondline thickness of about 6 mils of the above adhesive composition was applied on a 3″×3″ medium density fiberboard (MDF). A wood veneer, also 3″×3″ was applied on top of the adhesive. Both the MDF and the wood veneer had been treated with Borax. A pressure of 50 psi at 200° F. was applied on top of the veneer for 30 seconds using Carver hot press. No gelling or other precipitation of the applied adhesive was observed. The MDF and wood veneer were strongly bonded together.
Results for Burning Characteristics
[0030] Articles made with the adhesive of the invention were found to pass the ASTM E 84 Standard Test for Surface Burning Characteristics of Building Materials, the ASTM C 236 Guarded Hot Box Test and the UL 723 Test for Surface Burning Characteristics of Building Materials.
[0031] Many modifications and variations of this invention can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. The specific embodiments described herein are offered by way of example only, and the invention is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled.
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The invention relates to waterbome adhesive compositions that make them suited for use in bonding to fire retardant treated wood and wood composites. The waterborne adhesive comprises resin emulsion stabilized by dextrin and/or surfactant. The invention is also directed to a method for bonding fire retardant treated wood or wood composite substrate to a similarly treated or to a dissimilar substrate. The invention is further directed to articles manufactured using the adhesive composition of the invention. The manufactured fire retardant articles are well suited for use in public places where large number of people assemble, e.g. offices, schools, hospitals, and the like.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/578,925, filed Dec. 22, 2011, which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] Laundry treating appliances, such as clothes washers, may include a perforate rotatable drum or basket positioned within an imperforate tub. The drum may at least partially define a treating chamber in which a laundry load may be received for treatment according to a selected cycle of operation. During at least one phase of the selected cycle, a motor may rotate the drum and laundry load about a rotational axis at a preselected sufficiently high speed to centrifugally extract liquid from the laundry load. The faster the drum may rotate, the more quickly the water may be removed from the laundry load. Thus, extraction may be optimized by maximizing the rotational speed of the drum, i.e. the maximum obtainable rotational speed as limited by the motor's capabilities, which may minimize the cycle time.
[0003] Although the motor may limit the maximum rotational speed of the drum, physical limitations of the system may prevent the maximum rotational speed from being safely obtained. One example of such a limitation may be a large inertia associated with the drum, such as from an unbalanced laundry load. If an inertia is too large, it may create a bending stress on the motor shaft or a hoop stress in the drum that would exceed the corresponding design limits. To maintain the operation within the design limits, the drum speed may be limited if the inertia is too large, i.e. the rotational speed may be reduced below the maximum rotational speed to prevent motor shaft and hoop stresses from becoming too great. However, extraction at a lower speed may lengthen the cycle time.
BRIEF DESCRIPTION OF THE INVENTION
[0004] A laundry treating appliance may have a rotatable drum defining a treating chamber for receiving a laundry load, a motor rotatably driving the drum, and a controller controlling the operation of the motor. The laundry treating appliance may be operated by accelerating the drum with the motor toward a final speed greater than a satellizing speed, determining a mass value indicative of the mass of the rotating drum and contents within the treating chamber during the accelerating, determining a current rotational speed during the acceleration, calculating a force value indicative of a force acting on the drum based on the determined mass value and the current rotational speed, comparing the force value to a reference force value, and repeating the determining, calculating, and comparing during the acceleration, and ceasing the accelerating when the force value obtains a predetermined relationship with the reference force value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] In the drawings:
[0006] FIG. 1 is an exemplary schematic view of a laundry treating appliance in the form of a washing machine according to an embodiment of an environment of the invention.
[0007] FIG. 2 is an exemplary schematic view of a control system of the laundry treating appliance of FIG. 1 according to an embodiment of the invention.
[0008] FIG. 3 is an exemplary graphical representation of rotational speed or torque vs. time for the washing machine of FIG. 1 comprising a sinusoidal signal superimposed on a constant acceleration signal.
[0009] FIG. 4 is an exemplary graphical representation of generally increasing rotational speed and generally decreasing torque for an extraction phase of a laundry cycle.
[0010] FIG. 5 is an exemplary graphical representation of a decrease in inertia with time for an extraction phase of a laundry treatment cycle.
[0011] FIG. 6 is an exemplary method flow chart for maximizing drum rotational speed by continuously monitoring inertia during an extraction phase of a laundry treatment cycle.
DETAILED DESCRIPTION
[0012] FIG. 1 is a schematic view of a laundry treating appliance showing one embodiment of an environment in which the invention operates. The laundry treating appliance may be any appliance which performs a cycle of operation to clean or otherwise treat items placed therein, non-limiting examples of which include a horizontal or vertical axis clothes washer; a combination washing machine and dryer; a tumbling or stationary refreshing/revitalizing machine; an extractor; a non-aqueous washing apparatus; and a revitalizing machine.
[0013] The laundry treating appliance of FIG. 1 is illustrated as a washing machine 10 , which may include a structural support system comprising a cabinet 12 which defines a housing within which a laundry holding system resides. The housing may have a chassis and/or a frame, defining an interior that encloses components typically found in a conventional washing machine, such as motors, pumps, fluid lines, controls, sensors, transducers, and the like. Such components will not be described further herein except as necessary for a complete understanding of the invention.
[0014] The laundry holding system comprises a tub 14 supported within the cabinet 12 by a suitable suspension system 28 , and a drum 16 provided within the tub 14 , the drum 16 defining at least a portion of a laundry treating chamber 18 .
[0015] The laundry holding system may further include a door 24 which may be movably mounted to the cabinet 12 to selectively close both the tub 14 and the drum 16 . A bellows 26 may couple an open face of the tub 14 with the cabinet 12 , with the door 24 sealing against the bellows 26 when the door 24 closes the tub 14 .
[0016] The suspension system 28 may dynamically suspend the laundry holding system within the structural support system.
[0017] The washing machine 10 may include a drive system 80 for rotating the drum 16 within the tub 14 . The drive system 80 may include a motor 88 , which may be directly coupled with the drum 16 through a motor drive shaft 90 , to rotate the drum 16 about a rotational axis during a cycle of operation. The motor 88 may be a direct-drive, brushless permanent magnet (BPM) motor having a stator 92 and a rotor 94 . Alternately, the motor 88 may be coupled to the drum 16 through a belt coupled with a drum drive shaft (not shown) to rotate the drum 16 , as is known in the art. Other motors, such as an induction motor or a permanent split capacitor (PSC) motor, may also be used. The motor 88 may rotate the drum 16 at various speeds in either rotational direction.
[0018] The washing machine 10 may also include a control system for controlling the operation of the washing machine 10 to implement one or more cycles of operation. The control system may include a controller 96 located within the cabinet 12 and a user interface 98 that is operably coupled with the controller 96 . The user interface 98 may include one or more knobs, dials, switches, displays, touch screens and the like for communicating with the user, such as to receive input and provide output. The user may enter different types of information including, without limitation, cycle selection and cycle parameters, such as cycle options.
[0019] The controller 96 may include a machine controller and any additional controller provided for controlling any of the components of the washing machine 10 . For example, the controller 96 may include the machine controller and a motor controller. Many known types of controllers may be used for the controller 96 , and the specific type of controller is not germane to the invention. It is contemplated that the controller may be a microprocessor-based controller that implements control software and sends/receives one or more electrical signals to/from each of the various working components to effect the control software. As an example, proportional control (P), proportional integral control (PI), and proportional derivative control (PD), or a combination thereof, i.e. a proportional integral derivative control (PID), may be used to control the various components.
[0020] As illustrated in FIG. 2 , the controller 96 may be provided with a controller memory 100 and a central processing unit (CPU) 102 . The memory 100 may store control software that is executed by the CPU 102 in completing a cycle of operation using the washing machine 10 , and any additional software. Examples, without limitation, of cycles of operation include: wash, heavy duty wash, delicate wash, quick wash, pre-wash, refresh, rinse only, and timed wash.
[0021] The memory 100 may store information in a suitable format, such as a database or tabular form, and may store data received from one or more components of the washing machine 10 that may be communicably coupled with the controller 96 . The database or tabular form may be used to store the various operating parameters for the one or more cycles of operation, including factory default values for the operating parameters and any adjustments to them by the control system or by user input.
[0022] The controller 96 may be operably coupled with one or more components of the washing machine 10 for communicating with and controlling the operation of the component to complete a cycle of operation. For example, the controller 96 may be operably coupled with the motor 88 . The controller 96 may also be operably coupled with a sump heater to heat wash liquid as required by the controller, one or more pumps, one or more valves for controlling the flow of liquid during a cycle of operation, a steam generator, and the like.
[0023] The controller 96 may also be coupled with one or more sensors associated with one or more systems of the washing machine 10 for processing and storing information from the sensors. Such sensors are known in the art and are not shown for simplicity. Non-limiting examples of sensors that may be communicably coupled with the controller 96 include a motor torque sensor 104 , which may be used to determine a variety of system and laundry characteristics, such as laundry load inertia or mass, and a motor speed sensor 108 for determining a speed output indicative of the rotational speed of the motor 88 . The motor speed sensor 108 may be a separate component, or may be integrated directly into the motor 88 . Regardless of the type of speed sensor employed, or the coupling of the drum 16 with the motor 88 , the speed sensor 108 may be adapted to enable the controller 96 to determine the rotational speed of the drum 16 from the rotational speed of the motor 88 .
[0024] The motor torque sensor 104 may include a motor controller or similar data output transducer (not shown) on the motor 88 that may provide data communication with the motor 88 and provide analog or digital motor characteristic signals, such as oscillations, to the controller 96 that may be indicative of an applied torque. The controller 96 may use the motor characteristics data to determine the torque developed by the motor 88 using an algorithm that may be stored in the controller memory 100 . The motor torque sensor 104 may be any suitable sensor, such as a voltage or current sensor, for outputting a current or voltage signal indicative of the current or voltage supplied to the motor 88 and enabling a determination of the torque applied by the motor 88 . Additionally, the motor torque sensor 104 may be a separate sensor or may be integrated with the motor 88 . For example, motor characteristics, such as speed, current, voltage, rotation direction, torque etc., may be processed such that the data may provide information in the same manner as a separate torque sensor. Contemporary motors often have a dedicated controller that outputs data for such information.
[0025] One or more load amount, or mass, sensors 106 may be included in the washing machine 10 and may be positioned in any suitable location for providing a mass output indicative of the mass of the rotating drum and laundry within the treating chamber 18 . By way of non-limiting example, it is contemplated that the amount of laundry in the treating chamber may be determined based on the weight of the laundry and/or the volume of laundry in the treating chamber 18 . Thus, the load amount sensors 106 may output a signal indicative of either the weight of the laundry load in the treating chamber 18 or the volume of the laundry load in the treating chamber 18 .
[0026] The load amount sensors 106 may be any suitable type of sensor capable of measuring the weight or volume of laundry in the treating chamber 18 . Non-limiting examples may include load volume, pressure, or force transducers, which may include, for example, load cells and strain gauges. The load amount sensors 106 may be operably coupled with the suspension system 28 to sense the weight borne by the suspension system 28 . The weight borne by the suspension system 28 may correlate to the weight of the laundry loaded into the treating chamber 18 such that the load amount sensor 106 may indicate the weight of the laundry loaded in the treating chamber 18 . In the case of a suitable load amount sensor 106 for determining volume, an IR or optical based sensor may be employed to determine the volume of laundry in the treating chamber 18 .
[0027] Alternatively, the washing machine 10 may have one or more pairs of feet extending from the cabinet 12 and supporting the cabinet 12 on the floor, and a weight sensor (not shown) may be operably coupled to at least one of the feet to sense the weight borne by the at least one foot, which may correlate to the weight of the laundry loaded into the treating chamber 18 .
[0028] In another example, the amount of laundry within the treating chamber 18 may be determined based on a motor sensor output, such as output from a motor torque sensor 104 . The motor torque may be a function of the inertia of the rotating drum and laundry load. Generally, the greater the inertia of the rotating drum and laundry, the greater the motor torque. There are known methods for determining the load inertia, and the load mass, based on the motor torque. It may be understood that the details of load amount sensors and motor torque sensors are not germane to the embodiments of the invention, and that any suitable method and sensors may be employed to determine the amount of laundry.
[0029] Prior to describing a method of operation in detail, a brief summary may be useful to aid in an overall understanding. The described embodiment may, during an operational cycle of the washing machine 10 , control the acceleration and/or rotational speed of the motor 88 , determine a mass value for the rotating drum and laundry, calculate a force value indicative of a force acting on the drum 16 based on the determined mass value and the rotational speed, compare the calculated force value with a reference force value, and control and ultimately terminate acceleration when the determined force value satisfies a predetermined relationship with the reference force value.
[0030] Extraction may begin by accelerating the drum and laundry items toward a satellizing speed. A reference force value that is indicative of a not-to-exceed force acting on the drum may be previously determined and stored in the memory 100 . At preselected time intervals during acceleration, a mass value indicative of the mass of the drum and laundry items may be determined. The mass value may be determined from an inertia value for the rotating drum and laundry load, or from other known methods. The inertia value may be determined during acceleration from changes in motor torque or motor power.
[0031] Contemporaneously, the rotational speed may be determined. A force value indicative of a force acting on the drum may be calculated based on the determined mass value and the rotational speed. The rotational speed may be determined by utilizing a known speed transducer or by other known methods. Thus, at preselected time intervals, a mass value, an inertia value, and a rotational speed may be determined.
[0032] The calculated force value may be compared to the reference force value. If the calculated force value is less than the reference force value, acceleration of the drum and laundry items may continue. At a preselected time interval, a mass value and an inertia value may again be determined, along with the rotational speed. Another force value may be calculated and compared to the reference force value. If the calculated force value is less than the reference force value, acceleration may continue. Thus, as long as the reference force value is not reached, the rotational speed of the drum and the laundry items may be steadily increased, thereby steadily increasing the rate of extraction of the liquid from the laundry items. When the calculated force value exceeds the reference force value, depending on the degree of exceedance the rotational speed may either be maintained at a constant value, or reduced until the calculated force value is less than or equal to the reference force value and the rotational speed may then be maintained at the constant value, i.e. the optimal extraction speed.
[0033] Extraction may continue at the optimal extraction speed, the mass value, inertia value, and rotational speed may be determined, and force values may be calculated and compared to the reference force value. As extraction continues, the mass value and inertia value may decrease, which may be reflected in a decrease in the calculated force value below the reference force value. The decrease in the calculated force value may enable an increase in the extraction speed, thereby increasing the rate of extraction. This continued increase in speed, determination of decreased mass value and inertia value, calculation of the decreased force value and comparison with the reference force value, and speed adjustment, may optimize the rate of extraction and enable a shorter extraction period.
[0034] The exemplary embodiment of the invention may enable the inertia of the laundry load to be determined during an acceleration phase that proceeds without the interposition of a constant speed phase. This may be accomplished by applying a periodic signal to an otherwise linear speed profile. It has been observed that the inertia of the laundry load may be determined by applying a periodic torque signal to the speed profile in such a manner as to split the periodic signal into two ½-period portions to enable the inertia of the laundry load to be solved by cancelling out damping and friction forces.
[0035] In all cases, the values for parameters used herein, like mass value, force value, and inertia value, need not be a direct determination or calculation of the corresponding value. While it may be possible to actually calculate the values, in most cases it may not be necessary to do so. Often an output, such as a voltage signal or the like, of a suitable sensor for a system parameter, such as inertia, torque, etc., can be used and compared to a reference value for the output for the parameter, which negates the need to go to the trouble to make a final determination. Thus, the values used in here include both absolute values or a referential value, which may serve to indicate a value without providing an absolute determination or calculation of the value, and the values may be a direct or indirect indicator of the parameter, such as torque under certain circumstances is an indicator of the inertia.
[0036] FIG. 3 illustrates a periodic torque profile/signal 70 superimposed over a constant acceleration phase 72 of a speed profile 68 . The periodic torque profile 70 may enable the inertia of the drum 16 and laundry load to be determined for each individual torque signal period 78 during the acceleration phase 72 . The periodic torque profile 70 may have a constant period 132 , and may comprise a plurality of periods. The torque from the motor 88 may be configured to periodically increase and decrease by communicating with the motor torque sensor 104 and/or the controller 96 . As a result, the resulting torque profile 70 may be in the form of a periodic trace, such as saw-toothed as illustrated, sinusoidal, or otherwise configured to enable the data analysis described hereinafter. The periodic torque profile 70 may be applied to the acceleration phase 72 by reference to a function or lookup table stored in the memory 100 in the controller 96 .
[0037] The speed profile 68 may include the acceleration phase 72 and an extraction phase 84 . The acceleration phase 72 may be linear, i.e. the rotational speed of the drum 16 and laundry load may increase linearly, thus the acceleration may be constant and continuous, although as discussed above it may also periodically vary somewhat. The acceleration phase 72 may be adapted to increase the rotational speed from zero up to an extraction speed, ES, 84 somewhat greater than a satellizing speed, SS, 82 . As used herein, the term “satellizing speed” refers to a drum rotational speed at which the laundry load satellizes, which may be higher than the speed at which satellizing first occurs.
[0038] The periodic torque signal 70 may be generated in different ways. A laundry load imbalance in the treating chamber 18 may induce a periodic torque or speed signal during the rotation of the drum 16 . Alternatively, if the torque or speed signal is not inherently periodic, the torque or speed signal may be conditioned to have a periodic component. Since power is proportional to torque and may be determined based on torque, torque may conversely be determined based on power consumed by the motor 88 .
[0039] Specifically, power, P=τ*ω. In this manner, the motor torque sensor 104 outputting a signal indicative of the torque of the motor 88 may effectively operate as a power sensor for generating a power signal indicative of the power provided to the motor 88 . This may be accomplished by the motor controller generating a periodic waveform as the basis for the acceleration phase 72 . The periodic waveform having a selected frequency, e.g. less than 2 Hz, may be superimposed on the acceleration phase 72 of the speed profile 68 .
[0040] The waveform may include a plurality of equal periods 78 . Each period 78 may be bisected into a first half period 74 corresponding to an increasing trace of the periodic waveform, representing a positive torque, and a second half period 76 corresponding to a decreasing trace of the periodic waveform, representing a negative torque. The first half period 74 and the second half period 76 may be alternately symmetrical with respect to the acceleration phase 72 .
[0041] It may be noted that the amplitude of the periodic torque signal 70 in FIG. 3 is exaggerated for clarification. In fact, the amplitude of each half period 74 , 76 may be limited to a small value to minimize the duration of any speed plateaus and optimize the time to reach the extraction speed 84 . The torque associated with the first half period 74 may be greater than the torque associated with the second half period 76 due to the alternating nature of the torque profile 70 . As illustrated in FIG. 3 , torque may increase during the first half period 74 and decrease or remain constant during the second half period 76 . From this, the inertia may be determined.
[0042] Generally, motor torque for rotating the drum 16 and laundry load may be represented as follows:
[0000] τ= J*{dot over (ω)}+B*ω+C, (1)
where, τ=torque, J=inertia, {dot over (ω)}=acceleration, ω=rotational speed, B=viscous damping coefficient, and C=coulomb friction. Utilizing the relationship expressed in equation (1), the torque for the first positive half period 74 and the second negative half period 76 may be determined in the following manner:
[0000] τ 74 =J*{dot over (ω)}+B*ω+C, (2)
[0000] τ 76 =J* (−{dot over (ω)})+ B*ω+C. (3)
[0000] Subtracting τ 74 from τ 76 , and solving for inertia,
[0000]
J
=
τ
76
-
τ
74
2
ω
.
,
(
4
)
[0000] in which {dot over (ω)} is constant.
[0044] Both τ 74 and τ 76 may be determined by output from the motor torque sensor 104 and/or the controller 96 . Acceleration, {dot over (ω)}, may be a known value, such as a preselected constant acceleration controlled by the controller 96 , or may be determined by a suitable sensor. Therefore, an inertia value may be determined for each single period 78 of the torque profile 70 as the acceleration phase 72 continues. A sequence of inertia values may be readily developed and stored in the memory 100 while acceleration progresses uninterrupted.
[0045] A mass value indicative of the mass of the rotating drum 16 and laundry load may be determined. The mass value may be determined as an equivalent of an inertia value, which as described above may be determined from a change in torque.
[0046] Rotation of the drum 16 and a laundry load contained therein may create a force on the motor drive shaft 90 , and/or a hoop force on the drum 16 , that exceeds a maximum design force value. This may be represented as:
[0000]
F
≡
J
*
ω
t
,
(
5
)
[0000] or, in other words, the force, F, is equivalent to the product of the inertia, J, and the rotational speed, ω, determined over a time period, t. F, however, is primarily a function of J and ω regardless of the magnitude of t. The motor drive shaft force and the hoop force may be determined as a combined value, or individually. The design limits for the drive shaft force and the hoop force may be established for a selected washer. Thus, the determined drive shaft and hoop forces may be compared to the design limits for the drive shaft and hoop forces, respectively. Alternatively, the determined value for the combined motor drive shaft force and hoop force may be compared to a design limit for the combined drive shaft force and hoop force. To maintain such forces within design limits, at least one of inertia and rotational speed may be controlled to maintain the drive shaft force and hoop force below a predetermined value corresponding to the maximum design force for the drum 16 . Rotational speed may be more readily controlled than inertia.
[0047] FIG. 4 is a graphical representation of a speed profile 124 illustrating an interrelationship between speed and torque over time. Speed may be increased linearly during a first acceleration phase 126 and a second acceleration phase 130 , as described previously herein. During the acceleration phases 126 , 130 , the torque may decrease as moisture is extracted. If the acceleration phases 126 , 130 are interrupted by a constant speed plateau 128 , it may be noted that torque will continue to decrease during the speed plateau, although at a reduced rate. Inertia values may be determined, i.e. updated, for selected speed or time intervals pursuant to equation (4); for example, time intervals 140 - 142 , 142 - 144 , 144 - 146 , 152 - 154 , 154 - 156 A, and so on. Inertia values may also be determined for a time interval 148 - 150 , if a speed plateau is included.
[0048] It may be noted that speed plateaus may be omitted so that the acceleration may be constant up to a selected extraction speed, which for this description may be a function of the design limits of the drum. FIG. 4 illustrates such a condition, in which the first acceleration phase 126 may continue unchanged beyond the time interval point 148 to the selected extraction speed 134 corresponding with a time interval point 156 B. As described previously herein, the constant acceleration to the selected extraction speed 134 may include small-amplitude oscillations superimposed on the constant acceleration. FIG. 4 illustrates that maintaining a linear speed profile may shorten the drying time by a time differential 138 as compared with the profile including the speed plateau 128 .
[0049] As the inertia may be repeatedly updated, the speed of the drum 16 and laundry items may be repeatedly updated. Therefore, the drum 16 may be controlled to rotate at or below a design maximum speed 136 corresponding to design limits for the drive shaft force and hoop force. The selected extraction speed 134 may be set at a value somewhat less than the design maximum speed 136 . The design maximum speed 136 may include a buffer, to which the drum may be accelerated. In those cases in which a buffer is not included, a buffer may be selected, which is represented by the extraction speed 134 . Additionally, the speed 134 may be selected based on the type of laundry. For example, certain fabrics may wrinkle more readily than others when subjected to high centrifugal forces. Thus, it may be desirable to set the speed 134 to avoid such wrinkling and the like.
[0050] When the rotational speed reaches the selected extraction speed 134 , acceleration may be discontinued so that extraction may continue at the selected extraction speed 134 . As the extraction progresses, however, the torque may continue to decrease in an asymptotic manner, as illustrated in FIG. 4 . As the torque may continue to decrease, the inertia may similarly decrease and approach an asymptote 169 .
[0051] FIG. 5 illustrates an idealized asymptotic inertia decay curve 110 . Referring as well to FIG. 4 , this exemplary asymptotic decay in inertia may be continuously monitored as the decay curve 110 approaches the asymptote 169 , until the inertia reaches an asymptotic reference value 164 representing an optimal extraction time 166 and residual moisture content (RMC). As the load spins at a high speed, liquid may be extracted from the laundry load. Initially, when the moisture content is high, the rate of liquid extraction may be large. As a result of this large liquid extraction, the inertia may drop substantially. However, as time passes at a high spin speed, less liquid may be extracted over a given period of time. As a result, the change in inertia may tend toward the reference value. Therefore, by monitoring the change in calculated inertia, the optimal time to stop spinning may be identified.
[0052] The high-speed portion of the spin cycle illustrated in FIG. 4 , i.e. the selected extraction speed plateau 134 , may be reflected in the continuing decrease in torque and inertia. As the torque and the inertia decrease, the rotational speed of the drum 16 and laundry load may also tend to decrease, dropping further below the design maximum speed 136 . Consequently, the drum 16 and laundry load may be accelerated to a first increased speed 158 greater than the selected extraction speed 134 . With the increase in speed, torque and inertia may again tend to decrease, in response to which the speed may be accelerated to a second increased speed 160 . This increase in speed following a decrease in torque and inertia may continue until a final increased speed 162 may be reached. At some point during the final speed increase 162 , the asymptotic torque reference value 164 may be reached, corresponding to an optimal extraction time 168 , at which point 166 , the extraction may be terminated.
[0053] While the increase in speed from the time interval point 156 A to the time interval point 168 is illustrated as preselected sequential steps, it need not be. It is just as likely that the increase in speed may be continuous, as exemplified by profile portion 126 A. The speed may also asymptotically increase in response to the asymptotic decrease of the inertia, i.e. inertia decreases and speed consequently increases, as exemplified by profile portion 126 B. Regardless of the manner in which the speed continues, both profile portions 126 A, 126 B may reach the design maximum speed 136 . In such a case, the controller 96 may be programmed to immediately terminate the operation cycle, reduce the speed to a value less than the design maximum speed 136 , reduce the speed to the selected extraction speed 134 , transmit an error or warning signal, and the like.
[0054] Referring now to FIG. 6 , a flow chart of a method for maximizing the rotational speed of the drum 16 in the washing machine 10 during extraction by continuously monitoring the inertia is illustrated. The sequence of steps depicted for this method is for illustrative purposes only, and is not meant to limit the method in any way as it may be understood that the steps may proceed in a different order, or additional or intervening steps may be included, without detracting from the invention. The method of FIG. 6 begins with the step 36 of determining a maximum force condition of the drum 16 as a function of 1) the mass of the drum and laundry load, and 2) a drum rotational speed. The maximum force condition may be determined for both the motor drive shaft 90 and hoop stress individually, or in combination.
[0055] A maximum drum rotational speed that is greater than a satellizing speed may be set in step 38 . The drum 16 and laundry load may be accelerated in step 40 toward a final speed greater than a satellizing speed for the washer 10 . At a preselected interval, which may be an interval of time, speed, or the like, the rotational speed of the drum 16 may be determined in step 42 . The torque may be determined at the preselected interval in step 44 . The difference in value of the torque at the immediately previous interval and at the preselected interval may be determined in step 46 , and utilized to determine an inertia value at step 48 .
[0056] From the inertia value, a mass value indicative of the mass of the rotating drum 16 and laundry load at the preselected interval may be determined at step 50 . A force value indicative of a force acting on the drum 16 may be calculated based on the determined mass value and the current rotational speed at the preselected interval at step 52 . The force value may be a calculated force, or may be represented by an inertia value, a change in torque, or the value directly correlated with a force acting on the drum at the preselected interval. The force value may be compared with a reference force value at step 54 .
[0057] The reference force value may be indicative of the maximum force condition, or a threshold force value less than the maximum force condition. If the force value exceeds the reference force value, the cycle may be terminated in step 58 . If the force value does not exceed the reference force value, the maximum rotational speed may be reset based upon the mass value and the determined rotational speed in step 56 , and the method may be repeated beginning with step 40 .
[0058] By monitoring the inertia of the drum and laundry load during extraction, the washer 10 may identify whether the inertia has decreased to a level that may enable the drum speed to be safely increased. Thus, the drum 16 and laundry load may always be spinning at a maximum safe spin speed, thereby extracting liquid from a laundry load in a minimum time.
[0059] While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing description and drawings without departing from the spirit of the invention, which is defined in the appended claims.
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A laundry treating appliance may have a rotatable drum defining a treating chamber for receiving a laundry load, a motor rotatably driving the drum, and a controller controlling the operation of the motor. The laundry treating appliance may be operated by accelerating the drum with the motor toward a final speed greater than a satellizing speed, determining a mass value indicative of the mass of the rotating drum and contents within the treating chamber during the accelerating, determining a current rotational speed during the acceleration, calculating a force value indicative of a force acting on the drum based on the determined mass value and the current rotational speed, comparing the force value to a reference force value, and repeating the determining, calculating, and comparing during the acceleration, and ceasing the accelerating when the force value obtains a predetermined relationship with the reference force value.
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GENERAL TECHNICAL FIELD
[0001] The present invention relates to the field of manufacturing methods for hollow turbomachine component, and more particularly to manufacturing preforms adapted to be assembled and placed in injection tooling for hollow turbomachine components.
STATE OF THE ART
[0002] Due to their specific geometry and their tolerances, hollow components used in turbomachines are complex to produce.
[0003] Such hollow components are typically produced by means of an injection process conventionally requiring the use of preforms positioned inside the injection mold, production of these preforms affecting the quality of the final part thus obtained.
[0004] However, production of such preforms is complex, and requires a plurality of distinct steps, each influencing the final quality of the part.
PRESENTATION OF THE INVENTION
[0005] The present invention aims to propose a method for producing preforms for the production of hollow turbomachine components, providing accurate positioning and dimensioning while still being operable at an industrial scale.
[0006] To this end, the invention proposes a forming method for a preform for a hollow turbomachine component, wherein
a sheet made of woven fibers is positioned on a base, said base being provided with a longitudinal impression, a mandrel is positioned in said longitudinal impression, so as to clamp said sheet between the base and the mandrel, the mandrel having a thickness that increases between a proximal end and a distal end, and having to longitudinal flanks substantially perpendicular to the base, the distal end of the mandrel is locked in position, a proximal block is placed resting on the base, so as to cover the proximal end of the mandrel, and said proximal block is locked, two flaps of the sheet are formed around the flanks of the mandrel, two lateral blocks are positioned resting on the base on either side of the mandrel, so as to clamp each flap between one of said lateral blocks and one flank of the mandrel, said lateral blocks are locked in place, drying of the assembly thus formed is carried out, so as to fix the shape of the sheet and thus form a preform thus including a flat base from which two flaps extend perpendicularly, the flaps are adjusted to the dimensions of the mandrel, by trimming away the excess material.
[0016] As a variant, said method has one or more of the following features, taken independently or in combination:
adjustment of the flaps to the dimensions of the mandrel is accomplished by positioning a tapping block opposite the edges of the mandrel, locking into position is accomplished by means of collets or clamping screws, said sheet is made of braided carbon fibers, and said preform is adapted for producing a turbomachine vane preform.
[0020] The invention also relates to a method wherein
two preform forming steps are accomplished by means of the method as defined previously so as to produce a first U-shaped preform and a second TT-shaped preform, the two preforms thus produced are associated by inserting the first U-shaped preform between the two flaps of the second TT-shaped preform, such that the bases of said two preforms are opposite and separated by their respective flaps, the assembly thus formed is placed in injection tooling.
[0024] The invention also relates to tooling for compacting, drying and trimming a preform of a hollow turbomachine component, characterized in that it includes:
a base, adapted to serve as a support to a sheet of material, including a longitudinal impression, a mandrel adapted to be position in said longitudinal impression, so as to clamp a sheet of material against the base, and thus defining two flaps of said sheet located on either side of the mandrel, said mandrel having a thickness that increases between a proximal end and a distal end, and having two longitudinal flanks substantially perpendicular to the base, two lateral blocks, adapted to be positioned resting on the base on either side of the mandrel so as to clamp the flaps of the sheet against the mandrel,
[0028] said lateral blocks and/or the mandrel being adapted to cooperate with means for trimming said flaps so as to adjust them to the dimensions of the mandrel or said lateral blocks, said tooling also including a proximal block, adapted to be positioned resting against one end of the mandrel, and to accomplish its locking against the base.
[0029] As a variant, said tooling has one or more of the following features, taken independently or in combination:
said lateral blocks and/or the mandrel have recesses adapted to accommodate a tapping block to as to absorb the excess during adjustment of the flaps to the dimensions of the mandrel or of said lateral blocks, the base, the mandrel, the lateral blocks, and the proximal block, if any, are made of resin, of thermoplastic material, of aluminum or of steel.
PRESENTATION OF THE FIGURES
[0032] Other features, aims and advantages of the invention will emerge from the description that follows, which is purely illustrative and not limiting, and which must be read with reference to the appended drawings, wherein:
[0033] FIG. 1 shows a view of a sheet of material placed on the base of tooling according to one aspect of the invention;
[0034] FIG. 2 shows a side view of a mandrel of tooling according to one aspect of the invention,
[0035] FIG. 3 shows a section view of the association of the base, of the sheet and of the mandrel shown previously,
[0036] FIG. 4 shows a view of the assembly presented in FIG. 3 , to which are added additional elements of the tooling according to one aspect of the invention,
[0037] FIG. 5 shows a detail view of locking into position of the mandrel,
[0038] FIG. 6 shows a section view of the assembly thus formed,
[0039] FIG. 7 shows a detail view of one zone of FIG. 6 ,
[0040] FIG. 8 shows an example of a preform obtained by means of the tooling shown previously,
[0041] FIG. 9 shows another variant of tooling according to one aspect of the invention,
[0042] FIG. 10 shows a detail view of one zone of the tooling shown in FIG. 9 ,
[0043] FIG. 11 shows another variant of a preform obtained by means of this tooling,
[0044] FIG. 12 shows an assembly of the two preforms presented previously,
[0045] FIGS. 13 and 14 shows two views of this assembly positioned in an injection mold according to one aspect of the invention.
[0046] In all the figures, the common elements are designated with identical numerical references.
DETAILED DESCRIPTION
[0047] FIG. 1 shows a sheet 1 of material positioned on a base 2 of forming tooling.
[0048] The sheet 1 is typically a sheet made of 3D-woven fibers, typically carbon fibers.
[0049] The base 2 includes a T-shaped impression 21 , thus having a longitudinal impression 22 and a transverse impression 23 . The sheet 1 of material is positioned so as to cover the longitudinal impression 22 , or more precisely so that the length of the sheet 1 is positioned between the two ends of the longitudinal impression 22 .
[0050] FIG. 2 shows a side view of a mandrel 3 adapted to be associated with the base 2 shown previously.
[0051] The mandrel 3 has the general shape of a wedge; it has a thickness that increased between a proximal end 31 and a distal end 32 , and having two longitudinal flanks substantially perpendicular to the base. Its distal end 32 extends into a typically parallelepiped attachment section 33 , adapted to rest against the base 2 and allow the mandrel 3 to be locked into position on the base 2 .
[0052] The length between the proximal end 31 and the distal end 32 of the mandrel 3 is advantageously equal to the length of the longitudinal impression 22 of the base 2 .
[0053] FIG. 3 shows a section view in a plane A-A shown in FIG. 2 of the mandrel 3 , as well as of the base 2 and of the sheet 1 of material.
[0054] The mandrel 3 is positioned so as to insert itself into the longitudinal impression 22 of the base 2 , the attachment section 33 of the mandrel resting against the base 2 outside of the longitudinal impression 22 , aligned with its end opposite to the end connected with the transverse impression 23 .
[0055] By thus positioning the mandrel 3 in the longitudinal impression 22 of the base 2 , a portion 11 (indicated in FIG. 3 ) of the sheet 1 of material is formed so as to conform to the longitudinal impression 22 of the base 2 , due to the action of the mandrel 3 .
[0056] Thus two flaps 12 and 13 are defined, located on either side of this portion 11 , that is on either side of the mandrel 3 .
[0057] FIG. 4 shows a view of the assembly consisting of the base 2 , the sheet 1 and the mandrel 3 , to which is associated a proximal block 4 as well as two lateral blocks 5 and 6 (only one lateral block 5 is shown in this figure).
[0058] The proximal block 4 has generally a T shape, and includes a first section 41 adapted to be inserted into the transverse impression 23 of the base 2 , and a second section 42 adapted to rest against the mandrel 3 positioned on the base 2 .
[0059] FIG. 5 illustrates the relative positioning of the sheet 1 , the base 2 , the mandrel 3 and the proximal block 4 , the second section 42 of the proximal block resting against the upper face of the mandrel 3 , so that the proximal end 31 of the mandrel 3 is held pressed against the base 2 .
[0060] FIG. 4 also shows the lateral block 5 , which is positioned on the base 2 so as to rest against a lateral face of the mandrel 3 .
[0061] The corresponding flap 12 is previously folded so as to extend along the lateral face of the mandrel 3 , substantially perpendicularly to the base 2 .
[0062] Thus, the flap 12 is clamped between the mandrel 3 and the lateral block 5 .
[0063] The second lateral block 6 is positioned similarly, so as to rest against the other lateral face of the mandrel 3 and to clamp the other flap 13 between the mandrel 3 and the second lateral block 6 .
[0064] FIG. 6 shows a cross-section view of the assembly thus formed. The U shape given to the sheet 1 can be seen, the different portions whereof are clamped between the base 2 , the mandrel 3 and the lateral blocks 5 and 6 .
[0065] FIG. 7 shows a detail view of a portion marked with a circle in FIG. 6 . Shown in this figure is the free end of the flap 12 , located between the mandrel 3 and the lateral block 5 .
[0066] So as to avoid considerable constraints in positioning the sheet 1 on the base 2 , the sheet 1 is advantageously dimensioned so as to be larger than necessary, which involves the flaps 12 and 13 extending beyond the mandrel 3 once the U shaping is accomplished, as can be seen in FIG. 7 .
[0067] Once the U shaping is accomplished, the two flaps and 13 are then adjusted to the height of the mandrel 3 , by trimming and removing the excess material.
[0068] This operation is typically accomplished while the assembly is in the configuration shown in FIG. 6 . A blade then cuts the excess material of the flaps 12 and 13 , by running along the upper edge of the mandrel 3 .
[0069] To this end, the lateral edges 5 and 6 advantageously include a recess adapted so as to receive a tapping block, that is a shim made of a soft material, adapted to absorb machining overruns during trimming and thus avoid damaging the lateral edges 5 and 6 . FIG. 7 thus shows a tapping block 51 positioned in a recess provided in the lateral edge 5 , at the upper edge of the mandrel 3 .
[0070] Conversely, it is possible to provide recesses in the mandrel 3 so as to place tapping blocks there, and to carry out the trimming operation by following the edge of the lateral blocks 5 and 6 .
[0071] These means adapted to carry out the adjustment and trimming of the flaps 12 and 13 directly in the tooling, allowing an accurate trim to be obtained, without deforming the preform and without removing fiber.
[0072] FIG. 8 shows the sheet 1 formed into a U positioned around the mandrel 3 , after removal of the lateral blocks 5 and 6 , of the proximal block 4 and of the base 2 . The sheet 1 thus formed has typically been dried before removal of these different elements, so as to fix it in this U shape.
[0073] FIG. 9 shows an assembly similar to that shown in the foregoing figures, wherein the TT shaping of a sheet 7 or material is accomplished. The various elements are designated with the same numerical references as before, followed by the letter a.
[0074] The sheet 7 is typically a sheet made of 3-D woven fibers, for example made of carbon fibers.
[0075] The different steps, as well as the means used, are similar to those described with reference to the foregoing figures, with the exception of the impression 22 a in the base 2 a, which is adapted so as to form a portion 71 larger than the portion 11 formed previously.
[0076] Moreover, the sheet 7 , as positioned initially in the base 2 a, consists of several panes which are positioned on the base 2 a. The mandrel 3 a is then positioned between two flaps 72 and 73 , along the longitudinal axis of the sheet 7 . The proximal block (not shown) and the lateral blocks 5 a and 6 a are then positioned so as to form a large portion 71 resting on the base 2 a, from which extend two flaps 72 and 73 , substantially perpendicularly to the portion 71 , these two flaps 72 and 73 extending to either side of the longitudinal axis of the portion 71 and being clamped between the mandrel 3 a and respectively the lateral flap 72 and the lateral flap 73 .
[0077] FIG. 10 shows a detail view of FIG. 9 highlighting the adjustment of the flaps 72 and 73 to the height of the mandrel 3 a.
[0078] As in the foregoing, the flaps 72 and 73 , as positioned on the base 2 a, are initially over-dimensioned, so as to avoid constraints connected with extremely accurate positioning of a sheet which was already dimensioned prior to forming.
[0079] As before, the two flaps 72 and 73 of the sheet 7 are adjusted by removing excess material, for example by means of a cutting tool running along the upper edges of the mandrel 3 a.
[0080] As described previously with reference to FIG. 7 , a tapping block can be used for carrying out the trimming operation.
[0081] As before, the trimming procedure can easily be reversed, by accomplishing it by running along the edges of the lateral blocks 5 a and 6 a, the mandrel 3 a then advantageously including one or more recesses for accommodating the tapping blocks.
[0082] In the embodiment shown in FIG. 10 , the mandrel 3 a has beveled lateral edges 32 a and 33 a, which allows them to serve as a guide for a trimming blade for example.
[0083] FIG. 11 shows a view of the sheet 7 formed into a TT shape, once the lateral blocks 5 a and 6 a, the proximal block 4 a, the mandrel 3 a and the base 2 a are removed. The sheet 7 thus shaped has typically been dried prior to removal of these different elements, so as to fix it in this TT shape.
[0084] FIGS. 1 to 11 thus show tooling and the different associated steps for producing two half-preforms typically made of 3D-woven fiber, carbon fiber for example.
[0085] The tooling described previously for producing these two preforms makes it possible to accomplish the operations of shaping, compacting, drying and trimming, for a given preform, in the same tooling, thus ensuring accurate shaping of these preforms.
[0086] FIG. 12 shows the assembly of the preforms thus formed from two previously formed sheets 1 and 7 , and illustrated in FIGS. 8 and 11 respectively.
[0087] As shown in this figure, the preforms previously produced are assembled, the U-shaped sheet 1 being inserted between the flaps 72 and 73 of the TT-shaped sheet 7 , so that their two portions 11 and 71 are opposite and separated by their lateral flaps 12 , 13 , and 73 , and the mandrel 3 used for U-shaping the sheet 1 is also positioned between these two portions 11 and 71 .
[0088] FIGS. 13 and 14 show section views illustrating positioning of the assembly thus formed in tooling 80 , typically injection tooling.
[0089] The tooling 80 includes a base 81 adapted to serve as a support for the portion 71 of the sheet that is given a TT shape, a proximal locking block 84 , lateral blocks 85 and 86 , and an upper block 87 .
[0090] These different elements are locked into position, so as to clamp the assembly of shaped sheets 1 and 7 and thus form an injection mold, making it possible to form a hollow turbomachine component, for example a vane platform of a turbomachine.
[0091] The different tooling elements presented, particularly the bases 2 , 2 a and 81 , the mandrels 3 and 3 a, the proximal blocks 4 , 4 a and 84 , the lateral blocks 5 , 5 a, 6 , 6 a, 85 and 86 , and the upper block 87 are typically made of resin or of thermoplastic material in the case where they are made by rapid prototyping, or of aluminum or of steel.
[0092] These different tooling elements are locked into position typically by means of collets or clamping screws, clamping being accomplished in the direction of the sheet 1 or 7 so as to clamp it between different elements of the tooling.
[0093] The invention thus makes it possible to produce a complex assembly of several preforms for producing a hollow turbomachine component, said preforms being capable of being placed directly into injection tooling.
[0094] The invention finds particular application for producing the vane platform of a turbomachine.
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The invention relates to an appliance ( 8 ) for compacting, drying and cutting a preform of a hollow component of a turbomachine, said appliance comprising: a base ( 2, 2 a ) acting as a support for a sheet of material ( 1, 7 ) and comprising a long impression ( 22, 22 a ); a mandrel ( 3, 3 a ) which can be positioned in said long impression, clamping the sheet of material against the base, thus defining two flaps ( 12, 13, 72, 73 ) of said sheet ( 1, 7 ) arranged either side of the mandrel ( 3, 3 a ); and two side blocks ( 5, 6, 5 a, 6 a ) which can be positioned such that they are supported on the base, either side of the mandrel, clamping the flaps of the sheet against the mandrel, said side blocks and/or the mandrel co-operating with means for cutting said flaps in such a way that they are adjusted to the dimensions of the mandrel or said side blocks.
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This is a division of application Ser. No. 07/968,913, filed Dec. 23, 1992, now U.S. Pat. No. 5,365,089.
FIELD OF THE INVENTION
The present invention relates in general to a bipolar transistor and in particular to a double heterojunction bipolar transistor having both emitter-base and base-collector junctions from different semiconductor materials.
BACKGROUND OF THE INVENTION
Heterojunction Bipolar Transistors (HBTs) are known in the art. For example see U.S. Pat. No. 4,768,074 entitled, "Heterojunction Bipolar Transistor Having an Emitter Region with a Band Gap Greater than that of a Base Region" to Yoshida et al. Double Heterojunction Bipolar Transistors (DHBTs) and Double Heterojunction High Electron Transistors (DHETs) are known in the art. For example see U.S. Pat. No. 5,010,382 entitled "Heterojunction Bipolar Transistor Having Double Hetero Structure" to Katoh. DHBTs and DHETs (DHTs) have one heterojunction between the emitter and base region and a second between the base and collector region. DHTs have many advantages over other types of bipolar transistors, such as enhanced emitter injection efficiency, lower base resistance, and lower base-emitter junction capacitance (C jbe ).
FIG. 1 is a cross-sectional view of a prior art GaAs-AlGaAs HBT 100 structure. The HBT 100 has an n-type GaAs collector layer 102, a p-type GaAs base layer 104, and an n-type Al x Ga 1-x As emitter 106 (x is the mole fraction of aluminum in AlGaAs) on an n + -GaAs substrate 108. The emitter 106 has two layers, a thick n - -type first emitter layer 106a on the base layer 104 and a thin n + -type second emitter layer 106b on the first emitter layer 106a and contacting emitter electrode 110. Collector electrode 112 contacts the sub-collector layer 108 and base electrode 114 contacts base layer 104.
The lower doping of first emitter layer 106a combined with its thickness reduces C jeb and increases the transistor's switching speed. To further improve transistor performance, the emitter and the collector current density must be at least 10 3 to 10 4 Amp/cm 2 . For the prior art HBT of FIG. 1, the reduced doping concentration of the emitter layer 106a reduces carrier injection into the base from the emitter to slow transistor turn-on. Because of this low doping concentration, a high forward-bias voltage V be is applied to the base-emitter junction to increase current density. However, because of this increased V be , excess carriers are stored in both the first emitter layer 106a and in collector layer 102. Consequently, the transistor's turn-off time t off increases. Since transistor switching speed is the average of t on and t off , a large t off offsets a reduction in t on and, therefore, is unacceptable.
A heterojunction formed from dissimilar semiconductor materials causes a conduction band discontinuity or spike, ΔE c , and a valence band discontinuity ΔE v at the interface of the two materials. ΔE c blocks the injection of low-energy carriers from the emitter region into the base region degrading emitter efficiency and, consequently, switching speed. Prior art attempts, e.g., grading the heterojunction, have failed to solve this switching speed degradation problem. For example, see L. F. Eastman, P. M. Enquist, and L. P. Ramberg, "Comparison of Compositionally Graded to Abrupt Emitter-Base Junctions Used in Heterojunction Bipolar Transistor," Journal of Applied Physics, Volume 61, pps. 2663-2669, 1987.
Prior art HBTs and DHBTs also suffer from high junction leakage currents. Several factors contribute to junction leakage, including base electron-hole recombination and laterally diffused carriers injected from the emitter into the extrinsic base. Consequently, HBTs have a lower current gain β than would otherwise be expected. Exacerbating this problem is the HBT β's non-uniformity, and the further reduction of β that results when HBT's are scaled. These problems compound each other, making HBTs unattractive for dense circuit integration.
PURPOSES OF THE INVENTION
It is a purpose of the present invention to reduce the parasitic capacitance between the base and the collector of Double Heterojunction Bipolar Transistors.
It is another purpose of the present invention to reduce base to emitter leakage in Double Heterojunction Bipolar Transistors.
It is still another purpose of the present invention to reduce base resistance in Double Heterojunction Bipolar Transistors.
It is still another purpose of the present invention to reduce lateral current diffusion between the emitter region and the extrinsic base region in Double Heterojunction Bipolar Transistors.
It is still another purpose of the present invention to improve the current gain efficiency of Double Heterojunction Bipolar Transistors.
It is still another purpose of the present invention to reduce parasitic capacitance, reduce base to emitter leakage, reduce base resistance and improve the current gain efficiency of Double Heterojunction Bipolar Transistors.
SUMMARY OF THE INVENTION
A Double Heterojunction Bipolar Transistor (DHBT) comprising: a first layer of a first semiconductor material; a second layer of a second semiconductor material; a third layer of said second semiconductor material; a fourth layer of said first semiconductor material; and a plug in said fourth layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiment of the present invention as claimed in the appended claims and described in the following specification may be better understood with reference to the attached drawings wherein like reference numerals correspond to the same or similar elements and:
FIG. 1 is a cross sectional view of the prior art single heterojunction bipolar transistor.
FIGS. 2A to 2I are steps in fabrication of a double heterojunction bipolar transistor according to the preferred embodiment of the present invention.
FIG. 3 is a band gap diagram for a portion of the preferred embodiment DHBT.
FIGS. 4A and 4B are doping profile diagrams of the preferred embodiment DHBT.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 2A-2I represent the steps in fabricating a Double Heterojunction Bipolar Transistor (DHBT) according to a preferred embodiment of the present invention.
First, in FIG. 2A, the layers of the multilayer wafer 120 are grown by the Molecular Beam Epitaxy (MBE) method. The wafer 120 has a 0.2 μm p + -GaAs first layer 122 doped to 10 19 /cm 3 , on a 50-100 Å n-type Al 0 .3 Ga 0 .7 As second layer 124 doped to 10 17 /cm 3 , on a 0.5 μm n - -Al 0 .3 Ga 0 .7 As third layer 126 doped to 5×10 16 /cm 3 , and a 0.5 μm n + -GaAs fourth layer 128 doped to 5×10 18 /cm 3 on a Semi-insulating fifth layer 130. A 0.3 μm SiO 2 layer 132 is deposited on the wafer by the Chemical Vapor Deposit (CVD) or, alternatively, by a sputtering method.
An emitter pattern is formed in photoresist using a conventional photoresist technique. The emitter's photoresist pattern provides an etch mask for etching the SiO 2 film 132. Area 140 is formed in the SiO 2 in FIG. 2B by reactive ion etching (RIE) with CF 4 gas as represented to expose the p + -GaAs layer 122. Next, a 0.20 μm concave portion 142 is etched into the exposed p + -GaAs layer 122 by a selective dry etching method using an etchant gas mixture of carbon dichlorodifluoride CCl 2 F 2 and helium (He). After etching the concave portion 142, a tri-layered plug 144 of layers of n-GaAs and n-Al 0 .3 Ga 0 .7 As is selectively grown in the concave portion 142. The plug top layer 150 is a 0.05 μm thick n-type GaAs layer doped to 3×10 17 cm -3 . The middle plus layer 152 is a 0.10 μm n-type Al 0 .3 Ga 0 .7 As layer doped to 2×10 17 cm -3 . The bottom plus layer 154 is a 0.05 μm n-type Al 0 .3 Ga 0 .7 As layer doped to 10 17 cm -3 . After growing these three plug layers using a Metal Oxide Chemical Vapor Deposition (MOCVD) method, any excess semiconductor on the SiO 2 layer 132 can be cleaned away with an etchant such as sulfuric acid.
Next, a second SiO 2 layer 160 in FIG. 2D, 0.2 μm thick, is grown on the first SiO 2 layer 132, and covering top emitter layer 150 in opening 140. Si ions are blanket ion-implanted, penetrating the second SiO 2 layer 160, but blocked by the combined thickness of the first SiO 2 layer 132 and the second SiO 2 layer 160 (0.50 μm). So, Si ion-implantation is limited in the plug 144 to area 162 with limited Si implantation in those regions of 150 and 152 blocked by any SiO 2 thicker than the second layer 160 and, therefore, blocked outside of area 162. Further, the second layer 160 minimizes surface damage to top emitter layer 150.
The next step is forming an extrinsic base region 170 in FIG. 2E. First, the two SiO 2 layers 132 and 160 are selectively etched using CF 4 , so that the emitter, plus layers 150, 152 and 154 remain covered by SiO 2 portion 172. Next, a 0.1 μm SiO 2 third layer 174 is formed on the wafer surface 120. Then, Mg is ion-implanted into the wafer 100 at a dose of 2×10 14 /cm 2 and energy level of 200 KeV to a depth of 0.35 μm. The Mg ions reach the interface of layers 124 and 126 where a new p ++ -GaAs region will be formed as base region 170. As a result of Mg ion-implantation, a portion of n-type Al 0 .3 Ga 0 .7 As layer 124 also will be converted to p ++ -type. However, the SiO 2 layers 172 and 174 mask the emitter region 140, restricting Mg ion implantation to the base 170 region. Finally, the implanted wafer 120 is annealed at 800° C. with an infra-red lamp. Annealing activates the Mg ions, forming the base region 170 p ++ -type.
After forming the base region 170, layer 174 is etched away from the base region 170 by CF 4 anisotropic RIE, leaving only portion 180 in FIG. 2F. A 500 Å Si 3 N 4 film 182 is deposited on the wafer by Plasma-CVD (P-CVD) and a 0.2 μm thick fourth SiO 2 layer 184 is formed on the Si 3 N 4 film 182. Boron ions are implanted at 150 KeV through the SiO 2 film 184 and Si 3 N 4 film 182 to a dose of 1×10 13 cm -2 to form a high resistance layer 186.
After forming the high resistance layer 186, the SiO 2 layer 184 is removed with buffered hydrofluoric acid and the Si 3 N 4 film 182 is removed with O 2 +CF 4 plasma leaving a cap 188 in FIG. 2G. Then, a portion of the SiO 2 cap 188 is removed by buffered hydrofluoric acid to leave the structure in FIG. 2H.
On the structure in FIG. 2H resistive electrodes are formed. The base electrode 190 is formed by depositing an AuZn alloy on the wafer and, then, etching the alloy with a mixture of iodine and potassium iodide to expose regions 170 and 186. The emitter electrode 192 is formed by removing enough SiO 2 to expose the extrinsic base 162 and then selectively depositing AuZn. After forming emitter electrode 192, the wafer is annealed at 400° C. so that emitter electrode 192 and n + -GaAs 150 both form ohmic electrodes. The collector electrode, 202 as shown in FIG. 2I, is formed by selectively dry etching the GaAs layer 119 with a mixture of the CCl 2 F 2 and H 2 with layer 126 acting as an etch stop. The exposed portion of Al 0 .3 Ga 0 .7 As layer 126 is wet etched using an etchant solution of NH 4 OH--H 2 O 2 --H 2 O to expose n + GaAs layer 128. A layer of 200 of SiO 2 is selectively deposited to mask the collector electrode 202, which is a metal alloy deposited on the exposed area of layer 128.
In the preferred embodiment of the present invention, the emitter has two regions, emitter region II 152 and emitter region I 154. These two emitter regions 152 and 154, are surrounded by heavily doped extrinsic base region 170, which is of opposite conductivity type. Consequently, the p ++ -type extrinsic base 170 and n-type emitter regions 152 and 154 prevent emitter carriers (electrons) from entering the extrinsic base region 170.
Additionally, the extrinsic base 170, which is far more heavily doped than the intrinsic base 204, separates the intrinsic base 204 from the SiO 2 surface (between the emitter and the base contact). Consequently, the extrinsic base creates the potential barrier represented in the valance band diagram of FIG. 3. Thus, when the base-collector junction is reverse biased, minority carriers are prevented from reaching the SiO 2 surface between the emitter and the base contact. High energy barriers at both sides force the emitter current to flow mainly through the interior portion 162 of the emitter and (intrinsic) base 204 improving both emitter efficiency and dc current gain β.
The preferred density of emitter dopant Si is provided in FIG. 4A. With the emitter ion-implanted to the dopant profile of FIG. 4A, the DHBT dopant profile of the preferred embodiment will be as in FIG. 4B. The dopant level is low in the collector region 126 (i.e., 10 16 cm -3 ), and high for the intrinsic base region 202 (i.e., 5×10 18 cm -3 ).
The thin layer 124 between the base 204 and collector 126 creates an electric field at that junction. This electric field reduces the electron blocking effect that plagued prior art graded base-collector junctions. Consequently, for the preferred embodiment, almost all of the base minority carriers are swept into the collector to the collector electrode, resulting in a significant increase in collector current I c over prior art DHBT's. Also, base to emitter junction capacitance is reduced, because the depletion layer at the base-emitter junction encroaches very little of the emitter region. Base to collector capacitance is also low, because the dopant density at least in one side of the base-collector junction is low. Thus, device capacitances for the preferred embodiment DHBT have been reduced over the prior art.
While the present invention has been described in terms of a preferred embodiment, numerous modifications and alterations will occur to a person of ordinary skill in the art without departing from the scope and spirit of the invention.
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A Double Heterojunction Bipolar Transistor (DHBT) and the method of fabrication therefor. First a layered wafer is prepared on a semi-insulating GaAs substrate. The bottom wafer layer is n + GaAs, followed by n - AlGaAs, a thin layer of n AlGaAs (which form the DHBT's collector) and a base layer of p + GaAS. A layered plug fills a trench etched in the base layer. The bottom two plug layers are AlGaAs and the top plug layer is GaAs. Next, an emitter is ion-implanted into the plug core and an extrinsic base region is ion-implanted. Finally, base, emitter and collector contacts are formed.
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This application is a continuation of application Ser. No. 07/597,923, filed Oct. 10, 1990 now abandoned.
The invention relates to an access door for aircraft nacelles.
BACKGROUND OF THE INVENTION
FIG. 1 illustrates an aircraft powered by fuselage-mounted engines (not shown) which are each contained within a nacelle 3. It is necessary for technicians to gain access to the interior of each nacelle 3, and so cowl doors 6A and 6B are provided. These doors are shown in more detail in FIG. 2. The two doors 6A and 6B enclose the engine. To access the engines, the upper door 6A and lower door 6B swings open about pivot points 14A and 14B.
However, the doors 6A and 6B, in swinging open, causes edge 18 to invade the space within the nacelle 3, as indicated by dimension 24, which is the depth of the invasion. This invasion is undesirable where the clearance 27 (shown at a location remote from the invasion for clarity) between the engine 30 and the inner surface 33 of the nacelle is small: the invasion can cause the edge 18 to contact the engine 30, which is to be avoided.
Prevention of such contact by increasing the clearance 27 is, in general, not feasible, because the clearance 27 is determined largely by considerations of weight and aerodynamic drag of the nacelle 3, and these considerations take precedence over door geometry. Thus, to prevent contact between edge 18 and the engine 30, the door opening mechanism must be re-designed.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an improved system for obtaining access to an engine disposed in the interior of an aircraft nacelle.
It is a further object of the invention to provide a linkage system for opening and supporting the nacelle cowl door and provide a linkage system which does not invade the nacelle interior upon opening.
SUMMARY OF THE INVENTION
In one form of the invention, a cowl door is supported from an aircraft nacelle such that the door not only opens to allow access into the nacelle, but also bodily swings away from the engine during opening. In another form of the invention, the opening and the swinging are linked such that they occur together.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates aircraft nacelles 3 with which the present invention can be used.
FIG. 2 illustrates a conventional cowl door in an aircraft nacelle.
FIG. 3 illustrates a perspective view of one form of the invention.
FIG. 4 illustrates a simplified cross-sectional view of the invention of FIG. 3, but with some components eliminated for ease of explanation and understanding.
FIGS. 5 and 6 illustrate views similar to that of FIG. 4, but with components restored to show operation of the invention in greater detail.
FIG. 7 illustrates a simplified schematic of the views of FIGS. 5 and 6.
FIG. 8 illustrates a sequence of positions attained by the linkage of FIGS. 5 and 6 during door movement.
FIGS. 9A and 9B illustrate another form of the invention, which includes a latch 107 for locking the door 43 in a closed position.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 illustrates one form of the invention, in which nacelle surface 40 corresponds to nacelle surface 40 in FIG. 1. A door 43 in FIG. 3 allows one to gain access to the interior of the nacelle. Because the linkage supporting the door 43 is somewhat complex, a simplified explanation of the linkage will first be given, followed by a more detailed explanation.
In FIG. 4, a radius arm 45 swings about a first pivot 48 which is fixed upon a frame 51 of the nacelle. The first pivot 48 does not move with respect to the nacelle frame 51, as indicated by the ground symbol extending from the pivot 48. Frame 51 is part of the support structure of the skin of the nacelle 3. The radius arm 45 supports the door 43 by means of a second pivot 54, also shown in FIG. 3. The second pivot 54, unlike the first pivot 48, does move with respect to the nacelle frame 51; the second pivot 54 travels along arcuate path 57 in FIG. 4 as the radius arm 45 rotates about the first pivot 48.
Thus, as shown in FIG. 4, the door 43 rotates about the second pivot 54, as indicated by dashed arc 59, while the second pivot 54 rotates about the first pivot 48, as indicated by dashed arc 57, with the radius arm 45 acting as a radius. This discussion will now consider the linkage which synchronizes the motion of door 43 with the motion of the radius arm 45.
The linkage of FIG. 3 is shown in side view in FIGS. 5 and 6. A simplified schematic of the linkage is shown in FIG. 7, and should be viewed together with FIGS. 5 and 6. FIG. 5 shows the door 43 in an open position, while FIG. 6 shows the door 43 in a closed position. In moving the door 43 from the closed position to the open position, the linkage functions as follows. As stated above, the first pivot 48 does not move, but the radius arm 45 rotates about the first pivot 48 as indicated by dashed arc 57 in FIG. 5. A first crank 58, termed the radius arm crank, is rigidly fastened to the radius arm 45: angle 60, between the radius arm 45 and the radius arm crank 58, is unchanging.
A second crank 63, termed the door crank, is integral to the door hinge 150 which is rigidly fastened to the door 43: angle 66, between the door 43 and the door crank, is also unchanging. A third crank 70, termed a drive crank, rotates about a third pivot 73, and drives both the radius arm crank 58 and the door crank 63 by means of a door link 76 and a radius arm link 79, which are pivotally pinned by pins 81, 83, 85, and 87, as shown in FIG. 7.
The third pivot 73, about which the drive crank 70 rotates, is supported and driven by a drive shaft which is integral to the nacelle frame. Thus, the third pivot 73, like the first pivot 48, is not movable with respect to the nacelle frame 51, as indicated by the ground symbol extending from the third pivot 73.
In operation, the drive crank 70 in FIG. 7 rotates as indicated by arrow 84, thus pulling radius arm crank 58 as indicated by arrow 91, thus rotating the radius arm 45 as indicated by arrow 94. At the same time, the drive crank 70 pulls the door link 76 as indicated by arrow 97, thus causing the door 43 to rotate as indicated by arrow 101.
The preceding paragraph has indicated that the drive crank 70 "pulls" door crank 63. This "pulling" may seem peculiar, because pin 81 in FIG. 7 may at first appear to be moving toward the door crank 63. However, the door crank 63 is being pulled away from pin 81, as indicated by arrow 94, by the motion of the radius arm 45. Thus, link 76 does in fact "pull" the door crank 63 during opening of the door 43.
FIG. 8 illustrates a sequence of positions attained by the components of FIGS. 5 and 6 during door motion.
Another embodiment of the invention is shown in FIG. 9, wherein a lock-down bar 105, also shown in FIG. 3, is held in place by a latch, or hook, 107 carried by the drive crank 70. As shown in FIG. 9, the latch 107 hooks over the lock-down bar 105 and prevents rotation of the radius arm 45 until the drive crank 70 rotates in the direction of arrow 110 and swings the latch 107 sufficiently free of the lock-down bar 105. Further, rotation of the door 43 is prevented so long as the lock-down bar 105 is held captive by the latch 107 because, at this time, the door crank link 76 prevents rotation of the door crank 63 about the door pivot 54.
A motor 115 in FIG. 3 can be used to rotate the drive crank 70. Alternately, a crank 116 can be used to drive a lug 118 which operates a gear train 121 in order to rotate the drive crank 70.
An invention has been described wherein an access door 43 in FIGS. 3 and 5 swings open without invading the space within the nacelle 3 as does doors 6A and 6B in FIG. 2. While it may be true that the drive crank 70 in FIGS. 5 and 6 does cause pin 87 to move in the direction of arrow 121 in FIG. 6 during rotation, and that such motion may be viewed as an invasion, this invasion is very small and can be minimized by modifying radius arm crank. Also, the thickness 125 in FIG. 3 of the drive crank can be less than one inch. Further, the drive crank can be located at any point along length 130. Thus, it is probable that a cavity can be found in the space allocated to the engine, such as cavity 133 in FIG. 2, which will allow the invasion of the drive crank 70 during rotation.
Several important features of the invention are the following. One, pivot 54 forms a first axis about which the door 43 rotates, and the first axis itself moves outward from the nacelle during door opening, as indicated by arrow 94 in FIG. 7. The motion of the first axis provides a clearance which allows access along the path indicated by arrow 140A in FIG. 3. Such access is not available along the analogous path 141 in FIG. 2. Further, the invention allows access along the paths of arrows 140A-140D in FIG. 3. Each of the paths indicated by arrows 140A and 140C are perpendicular to the paths indicated by arrows 140B and 140D.
Two, a pair of radius arms 45 is shown in FIG. 3. The pair of arms forms a frame which supports the door 43. The three elements including plate 150, the pin (not numbered) located at pivot 54, and the frame act to form a hinge which allows the door 43 to rotate about the pivot 54. Similarly, nacelle frame 51, pivot 48, and the pair of arms 45 form a second hinge.
Three, simultaneous rotation of the radius arm 45 about the first pivot 48 occurs with rotation of the door 43 about the second pivot 54. However, "simultaneous" does not necessarily mean that the two rotational speeds are equal, nor that the amounts of each rotation are equal. In general, the speeds and amounts are not equal, as analysis of FIG. 8 will show.
The above embodiments disclose one of several hinges which can be employed in connection with the nacelle door of the present invention. Kinematics of this hinge mechanism can be adjusted to form a straight line instant center, through multiple hinge points. Thus, this hinge is particularly useful on curved surfaces such as nacelles.
Numerous modifications and substitutions can be undertaken without departing from the true spirit and scope of the invention. For example, the linkage of the invention can be used in automotive applications, such as in the hood or trunk of a car. The linkage would allow unrestricted access to the interior.
It will be readily understood by those skilled in the art that the present invention is not limited to the specific embodiments described and illustrated herein. Different embodiments and adaptations besides those shown herein and described, as well as many variations, modifications and equivalent arrangements will now be apparent or Will be reasonably suggested by the foregoing specification and drawings, without departing from the substance or scope of the invention. While the present invention has been described herein in detail in relation to its preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. Accordingly, it is intended that the invention be limited only by the spirit and scope of the claims appended hereto.
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The invention concerns a hinge system for cowl doors in nacelles for aircraft engines. The invention allows the cowl door to be opened without invasion of the interior of the nacelle. Invasion requires that some interior space of the nacelle be kept free of equipment. The invention eliminates this requirement, allowing otherwise idle space to be utilized.
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MICROFICHE APPENDIX
A Microfiche Appendix presents a computer program that demonstrates various control aspects for the operational processes of the spectrophotometer, as described herein. This Appendix is captioned "Appendix; Submission of Computer Program Listing in Application for U.S Letters Patent: OPTICAL SPECTROPHOTOMETER HAVING A MULTI-ELEMENT LIGHT SOURCE," and it contains thirteen total frames in one microfiche.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of optics and, more particularly, to spectrometric devices of the type incorporating a multiplex or Fellget advantage. Still more specifically, the invention pertains to a spectrophotometer using an array of radiation emitting elements configured for activation in Hadamard encodement or Fourier frequency encodement patterns.
2. Description of the Prior Art
Recent prior art regarding spectrometric devices of the type incorporating a multiplex or Fellget advantage have focused primarily upon various "masking" devices that implement the Hadamard multiplex advantage. The book "Hadamard Transform Optics" by Martin Harwit, et al., published by Academic Press in 1979, provides an excellent overview of the applied mathematical theory and the degree to which common optical components are used in Hadamard spectroscopy and imaging applications. Fateley U.S. Pat. No. 4,799,795, hereby incorporated by reference, discloses an electronically alterable vanadium dioxide crystalline mask interposed in an optical pathway between a light source and a detector. This mask has a matrix of optical cells activated by a computer linkage to form various Hadamard encodement patterns which consist of spatially arranged sets of cells in either opaque or transparent modes. Electronically operable masks present a distinct advantage over mechanically operated masks which are subject to misalignment, jamming, and lack of scan repeatability.
While the electronically alterable masks provided a significant advance in the state of the art, problems still remain. First, the cell components of the electronically alterable mask each contribute their own band of absorption to the spectra for analysis, which fact may detrimentally affect detector count readings within critical spectral regions of interest. Second, components within the cells may polymerize when they are exposed to certain spectral regions of light such as ultraviolet light, which circumstance renders the mask inoperable. Finally, although the crystalline mask operates more quickly than did the various prior mechanical mask devices, the individual cells of the crystalline mask still require a transition relaxation time to pass between the opaque and transparent modes. This relaxation time requirement and related delays may, under some operational demands, become a limiting factor in spectroscopic analysis.
Laser spectroscopy provides distinct advantages over conventional non-laser spectrophotometers in certain fields including absorption spectroscopy, fluorescence spectroscopy, Raman spectroscopy, and long range (e.g., atmospheric) spectroscopy. The advantageous laser characteristics include enhanced brightness, enhanced spectral purity, directionality, and the ability to produce light in extremely short pulses. Unlike the early laser amplifier materials that typically fluoresced light over a very narrow spectral region, modern materials, and particularly the organic laser dyes, are capable of fluorescing light in a relatively broad spectral range. This characteristic allows individual lasers to be tuned for output to different narrow spectral ranges by adjusting the angle at which laser light strikes a monochromator. The output can be further tuned for an extremely narrow frequency by additionally incorporating such devices as a Fabry-Perot etalon, which are also adjustable at different angles. An overview of this type of tuning apparatus particularly regarding dye lasers exists in the book "Topics in Applied Physics", Dye Lasers, Vol. 1, edited by F. P. Schafer, pp. 38-39, 69, 131, 190-193, published by Springer-Verlag in 1973, but similar apparatus is known in the art.
SUMMARY OF THE INVENTION
The present invention solves the prior art problems discussed above and provides a distinct advance in the state of the art. More particularly, the spectrophotometer hereof provides for very rapid analysis of a sample using Hadamard techniques without experiencing signal loss through mask absorption, and similar apparatus can apply Fourier techniques to generate an interferogram, which is analogous to interferograms from Fourier-type interferometry, by superposing waves of different frequencies without requiring the use of a beam splitting device such as those that are commonly applied in Fourier interferometry.
The present invention broadly includes an electromagnetic radiation source array composed of a plurality of solid state source elements configured for allowing activation in a plurality of multiplexing encodement patterns, a detector for detecting radiation emitted from the elements and for producing signals representative thereof, and electronic controls for activating the array patterns and for producing multiplex analyses of the signals. More particularly, the apparatus incorporates an optical pathway for directing radiation from the array to the detector with a diffraction grating in the pathway for dispersing and collimating the radiation so that selected components thereof are directed for impingement on the detector. In another embodiment, an organic dye cell placed between semitransparent mirrors receives focused radiation from the source elements whereupon lasing action is induced for laser spectrophotometry.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of the preferred spectrophotometer apparatus of the present invention;
FIG. 2 is a block diagram of the apparatus of FIG. 1;
FIG. 3 is a front elevational view of the preferred diode array;
FIG. 4 is a schematic three dimensional representation including the output slit assembly for the spectrophotometer of FIG. 1;
FIG. 5 is a schematic representation of a second embodiment of the present invention illustrating a laser spectrophotometer; and
FIG. 6 is a schematic three dimensional representation of the output slit assembly for the spectrophotometer of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 schematically illustrates the preferred spectrophotometer apparatus 10 which includes radiation source array 12, diffraction grating 14, output slit assembly 16, detector 18 and control assembly 20. Preferred array 12 includes eighty light-emitting diodes (LED) 22 as illustrated in FIG. 3.
As seen in FIG. 3, diodes 22 are arranged in four off-set rows 24-30 of twenty columns 32-70. As illustrated, diodes 22 emit light in different colors and the columns are arranged according to wavelength to present green region 72 (columns 32-36), yellow region 74 (columns 38-42), orange region 76 (columns 44-48), red region 78 (columns 50-64) and near infrared region 80 (columns 66-70).
Within each column 32-70, rows 24-30 are offset by one-quarter of a diode diameter for reasons that will become apparent below. Light emitting diodes are generally solid state devices that are constructed from various percentage alloy compositions to produce light of certain wavelengths. As those skilled in the art can appreciate, diodes 22 are selected according to the desired wavelength as illustrated by the examples of Appendix I. As semiconductor technology progresses, devices may be developed that emit radiation wavelengths not currently available, but which can be advantageously used in the present invention.
Diffraction grating 14 is of a concave, aberration corrected, holographic construction available from American Holographic of Littleton, Mass. Grating 14 has a concave gold or aluminum covered reflective focal surface that incorporates very fine rulings for monochromating and collimating light. Grating 14 presents an axis of symmetry 82 that passes through center point 84.
Slit assembly 16 is positioned below array 12 and is illustrated in more detail in FIG. 4. Assembly 16 includes slit body 86 with optical slit 88 defined therein, structure defining optical chamber 89, fiber optic coupler 90 coupled to body 86 in a position to receive radiation from chamber 90, fiber optic cable bundle 92 extending from coupler 90 to detector 18, stepper motor 94 presenting output shaft 96, tubular motor coupling 98 receiving shaft 96 in one end thereof, and stub shaft 100 having one end thereof received in the other end of coupling 98 with the other end of stub shaft 100 threadably received in shifting bracket 102. Activation of motor 94 causes rotation of shaft 96, coupling 98 and shaft 100. Rotation of the threaded end of stub shaft 100 shifts bracket 102 and thereby shifts body 86 and slit 88 so that a different set of radiation wavelengths are received therethrough. Thus, by selective controlled activation of motor 94, the set of wavelengths impinging upon detector 18 can be varied to suit the particular analyses being performed.
Preferred detector 18 is a lead sulfide photoresistor available from Infrared Associates, Inc. of Orlando, Fla., or Epitaxx, Inc. of Princeton, N.J. Other suitable detectors include a silicon photodiode or photovoltaic cell, an indium gallium arsenide phosphide photodiode or photovoltaic cell, or a phototransistor. In operation, detector 18 produces a voltage signal in response to and representative of the radiation impinging thereon.
Referring now to FIG. 2, control assembly 20 includes conventional, IBM compatible personal computer 104 (with a 486 type microprocessor), interface 106, Hadamard pattern generator 108, array driver 110, stepper motor controller 112, and analog to digital converter (ADC) 114 incorporating a preamplifier, operably interconnected as shown. Conventional interface 106 operates as a protocol converter enabling communications between computer 104 and devices 108-114.
Conventional pattern generator 108 includes an EPROM memory device (not shown) which stores the various Hadamard encodement patterns for array 12. In response to control signals from computer 104, generator 108 delivers signals representative of successive encodement patterns to driver 110. More particularly, generator 108 produces output signals to driver 110 indicating which of diodes 22 should be active during a particular encodement pattern. Moreover, the activation signals for a given pattern are in the form of oscillating on/off, i.e., square wave, signals so that the activated diodes are synchronized to emit light in this on/off manner, preferably at the rate of at least ten oscillations during each encodement pattern. Energizing diodes 22 in this manner allows electronic filtering of noise from the voltage signals of detector 18. As those skilled in the art will appreciate, this is analogous to mechanical "chopping" without the attendant disadvantages thereof and thereby presents a significant advantage of the present invention.
Conventional driver 110 includes a current stabilizer and a voltage regulator to yield very consistent output for energizing each of diodes 22 in square wave oscillation when activated.
Conventional stepper motor controller 112 allows computer 104 to position output assembly 16 with a degree of precision enabling scan repeatability. More particularly, controller 112 receives signals from computer 104 by way of interface 106 and converts these signals into a format suitable for activating stepper motor 94 to rotate the desired number of steps in order to position slit 88 for passage of the desired wavelengths.
ADC 114 is conventional in nature and receives the voltage signals from detector 18, amplifies these signals as analog input to the converter in order to produce a digital output representative of the voltage signals. As discussed further hereinbelow, computer 104 provides periodic activation signals to ADC 114 which responds by performing a conversion and delivering a digital output to computer 104 by way of interface 106.
Array 12, grating 14, slit assembly 16 and detector 18 cooperatively define optical pathway 116. Radiation emitted from array 12 impinges initially on grating 14 which separates the radiation into spectral components. Even though diodes 22 individually present a narrow spectral output, grating 14 further spreads the spectrum into finely resolved components. A spectral component from each energized diode is then reflected by grating 14 toward slit 88 so that a selected set of spectral components impinge on detector 18, the other component sets being prevented from impinging on detector 18 by the position of slit 88. When a different set of components are desired, computer 104 activates stepper motor 94 to shift slit 88 to allow the desired component sets to pass therethrough.
More particularly, the various elements of optical pathway 116 present a spatial arrangement that determines the way in which they interact to manipulate light from array 12. Light of combined wavelengths from the individual diodes 22, e.g., diodes 118 and 120, may operatively strike anywhere upon the surface of grating 14, but radiation paths 122 and 124 determine the horizontal angles β and β' between axis of symmetry 82 and respective paths 122, 124 to point 84. In this way, each diode 22 has a unique angle β that serves to affect dispersion optics. Reflective path 126 extends downwardly from the grating surface, below array 12, through output slit 88, through sample chamber 89, and through fiber-optic cable 90 to detector 18. Angle α measures the horizontal angle between axis of symmetry 82 and path 126.
By way of operational overview, diodes 22 are activated to emit radiation in a successive set of Hadamard encodement patterns. The resultant set of spectral components passing through slit 88 is detected by detector 18 which provides signals representative thereof. Computer 104 then processes these signals to produce a Hadamard analysis. Computer 104 operates according to a control program that governs the operations of spectrophotometer apparatus 10. A copy of this program, which is written in Basic, is submitted herewith as the Microfiche Appendix. The program listing is an exemplary way of demonstrating a control mechanism for data acquisition, the clock synchronization of the various components, and a direct mathematical solution for the S 79 Hadamard matrix.
Computer 104 initiates an analysis by prompting pattern generator 108 to activate the successive Hadamard encodement patterns on array 12 by way of driver 110. More particularly, array 12 includes eighty diodes 22 which requires seventy-nine Hadamard encodement patterns in which a different sets of diodes 22 are active and inactive during each pattern according to well known Hadamard mathematics. With each pattern, a set of wavelength components are resolved by grating 14 and directed along path 126 through slit 88 onto detector 18. In synchrony with the activation of encodement patterns, computer 104 also takes readings from ADC 114, that is, samples data at a rate of at least twice that of the oscillation of diodes 22 during activation. These readings enable computer 104 to solve a conventional fast Fourier transform and thereby eliminate background noise from the readings for analysis.
For example, diodes 118,120 produce light that includes the specific wavelengths λ a and λ b . Light from diodes 118,120 travels along respective exemplary paths 122,124 to strike diffraction grating 14 for dispersion and collimation into approximately singular wavelength band components, e.g., λ a and λ b . The combined reflection forms a beam along path 126, and the beam contains a combination of wavelengths, λ a , λ b , etc. In this manner, the beam contains one wavelength component representation for each activated diode of the array. The beam along path 126 passes through sample chamber 89 where material may be inserted for spectrographic analysis, and it then impinges upon detector 18.
In response, detector 18 sends a resultant analog voltage signal to detector ADC 114, which converts the signal to digital for transmittal to interface 106, which in turn sends it to computer 104. Computer 104 receives the detector signals within a time domain that is synchronized with the pattern activation signal for array 12, and the process is repeated in a sufficient number of different Hadamard patterns (e.g., seventy-nine) to constitute a complete scan. Computer 104 then applies the detector signals as input to solve a conventional Hadamard algorithm that mathematically yields intensity counts in respective wavelengths (e.g., λ a and λ b ) that represent each of diodes 22.
One complete set of encodement patterns constitutes one "scan" and, in the preferred embodiment, sixty-four scans are performed per second. Because of the rapid response time of the preferred diodes 22, it is possible to operate array 12 at this scan rate which has not been possible in the prior art. Additionally, this rapid scan rate allows many sets of data to be taken and averaged in order to increase the overall accuracy of the analysis. After one analysis is performed, computer 104 can activate slit assembly 16 to shift slit 88 to allow passage of a different set of spectral components in order to perform another analysis using these components.
As those skilled in the art will appreciate, the present invention can also be used to superpose waves of different frequencies and thereby generate an interferogram that is analogous to a Fourier-type interferogram as can be obtained for example from a Michelson interferometer, except that the present invention does not require a beam splitting device in order to develop the interferogram. In such an application, pattern generator 108 energizes each of diodes 22 at a discrete, known oscillation frequency to produce a Fourier frequency oscillation pattern. With these discrete oscillation frequencies, computer 104 can use the corresponding data received from detector 18 to mathematically extract for the Fourier type interferogram the intensity of each optical frequency. Such a result would avoid the need for the traditionally requisite beam splitting Fourier interferometer device. Although the Hadamard device is most preferred, the invention still contemplates both the Fourier type of frequency oscillation device and the Hadamard device as generally incorporating "multiplexing encodement patterns."
FIG. 5 schematically illustrates laser spectrophotometer 128 as a second embodiment of the present invention, wherein components in common with spectrophotometer 10 are numbered the same. This second embodiment additionally includes lenses 130, first semitransparent mirror 132, organic dye cell 134, second semitransparent mirror 136, and grating positioning assembly 138. In this embodiment, diodes 22 are preferably identical and emit radiation in the same spectral band. While appropriate diodes may be selected from a broad range of possibilities, the most preferred diodes have a high external quantum efficiency and a narrow bandwidth, such as the "superbright" AlGaAs diodes that operate in the visible red to near infrared spectral regions and can have a mere 35 nm halfwidth.
Lenses 130 are positioned respectively in front of diodes 22 and are preferably miniature, graded-index (GRIN) rod lenses which act to focus light by changing the index of refraction in a glass rod. GRIN lenses are commercially available under the trade name "SELFOC" lenses from NSG America, Inc. of Somerset, N.J. Lenses 130 focus light to a point that lies approximately midway through dye cell 134. Mirrors 132,136 have metallic or multiple dielectric coatings, and cooperatively function as a laser oscillator across dye cell 134. Mirrors 132,136 are of a commercially available variety as sold, for example, by Optical Coatings Laboratories, Inc. of San Francisco, Calif. First mirror 132 is transparent to light from array 12, but it is highly reflective to light of wavelengths that fluoresce from dye cell 134. Second mirror 136 is semi-transparent to light of the fluoresced wavelengths from dye cell 134.
Laser dye cell 134 contains an organic laser dye that acts as a laser amplifier by receiving light of primary wavelengths originating from array 12, and then emitting or fluorescing secondary light of lasing frequencies. Suitable compounds are widely known in the art, and generic categories include, by way of example, 3,3'diethylthiacarbocyanine iodide in a glycerol solvent (having a flash pumped peak lasing wavelength of 625 nm), or 1,3,3,1',3'3'-hexamethylindocarbocyanine iodide in a DMSO solvent (having a flash pumped peak lasing wavelength of 740 nm). Some commercial laser dyes are particularly advantageous because they fluoresce in a relatively broad bandwidth, e.g., LD 700 (Perchlorate) as sold by Exciton Corporation of Dayton, Ohio, fluoresces between 700 nm and 840 nm when it is flash pumped by an array of superbright Ga 0 .4 Al 0 .6 As diodes that have a halfwidth of 35 nm from 615 to 685 nm.
Grating positioning assembly 138 includes pivot bracket 140, stepper motor 142, and linkage 144 interconnecting the output shaft of motor 142 with grating 14 so that stepwise activation of motor 142 selectively and precisely shifts grating 14 about the pivot point of bracket 140. Motor 142 is electrically coupled with computer 104 in place of motor 94 for controlled activation thereof for the adjustment of angle α.
In operation, diodes 22, e.g., 118, 120, produce light that passes through lenses 130 which operate to focus light from diodes 22 through mirror 132 and to excite dye cell 134 to a fluorescence emission state. The nature of organic laser dye is such that the florescence occurs in localized regions called "cuvettes" around the focal points of each of lenses 130. For example, cuvettes 144, 146 fluoresce along paths 122, 124 across from diodes 118, 120. Cuvette regions 14, 146 fluoresce light containing respective wavelengths λ a and λ b which travel along exemplary paths 122, 124 to diffraction grating 14 for collimation after which the light travels downwardly along path 126 to strike second mirror 136. Light in path 126 contains combined wavelengths λ a and λ b that represent cuvette regions across from each of diodes 22, e.g., cuvettes 144, 146. Second mirror 136 reflects the light back to diffraction grating 14, which reflects the light along upper path 148 back through laser dye cell 134 to first mirror 132. First mirror 132 reflects the light again back along path 148, and this reflective oscillation process repeats itself until the light is of sufficient intensity to pass through second mirror 136, that is, until the assembly begins to lase. In this manner, mirrors 132, 136, diffraction grating 14, and dye cell 134 cooperate to form an amplifier and oscillator apparatus for producing or developing laser light.
During operation, each cuvette in dye cell 134 produces a spectral output over a relatively wide bandwidth which is characteristic of the organic dyes used. Grating 14 then disperses the incident radiation from each cuvette and reflects a very narrow spectral component thereof along path 126. It will be appreciated, however, that the reflected spectral component depends upon the spatial position of the cuvette emitting the radiation relative to grating 14. Thus, each fluorescing cuvette will contribute a different spectral component to the set of components reflected toward second mirror 136.
When a different set of spectral component is desired, computer 104 activates stepper motor 142 to shift grating 14 and thereby reflect a different set of spectral components from the cuvettes toward second mirror 136. In this way, spectrophotometer 128 can be easily and precisely "tuned" to the desired set of frequencies for a particular analysis. In this way, spectrophotometer 128 presents a tunable laser spectrophotometer incorporating a multiplex advantage.
As those skilled in the art will appreciate, the present invention encompasses many variations in the preferred embodiments described herein. For example, the preferred spectrophotometers herein generally depict an optical pathway that contains a concave diffraction grating in an apparatus that is operated in reverse. The optical pathway could also consist of a less preferred conventional Czerny-Turner apparatus that would require more complex and less efficient dedispersion optics. In other embodiments, the optical pathway could incorporate a prism instead of a diffraction grating or other equivalent means for dispersing wavelengths. Similarly, array 10 may consist of identical diodes having a narrow bandwidth that does not require a diffraction grating for dispersion, in which case the optical pathway would linearly extend between the source array and the detector. The optical pathway could alternatively consist of optical fibers where diodes 22 discharge light directly into such fibers for delivery to a sample for analysis.
Of course, there exists a broad range of alternative laser light sources that will function suitably in the invention. Lasers generally require an amplifier and an oscillator, e.g., where mirrors 132, 136 form an oscillator, organic dye cell 134 is the most preferred type of amplifier. Other types of amplifier material, such as titanium sapphire, can be used in place of cell 134. Of particular interest in this regard are standard diodes that themselves produce laser light, such as the injector laser diodes which are made by Meredith Instruments of Glendale, Ariz. These diodes can replace the normal diodes 22 of array 12 to produce laser amplified light, without dye cell 134, because the diode alloy forms its own laser amplifier. Similarly, these laser diodes may employ different combinations of reflective surfaces formed of crystal cleavage planes and reflective coatings to obviate the need for mirrors 132, 136. Laser diodes of various colors are available. Those skilled in the art will appreciate that many different sources of laser light can be used in the invention.
Additionally, Hadamard matrices mathematically require that the matrix have an order of 1, 2, or any multiple of 4, although, one element of the matrix may not be activated in a given scan. Thus, a Hadamard source array could for example, instead of containing 80 elements as depicted for an S 79 matrix, contain 24, 40 or 320 elements.
______________________________________APPENDIX ILED CategoriesElemental Semi-Conductor General Spectral Peak Wavelength,Composition Region Description nm______________________________________GaAs Near Infrared 860Zn-doped GaAs Near Infrared 870Si-doped GaAs Near Infrared 910-1020Si Doped GaAs Commercial 914, 925, 940, 950, Emitters Available and 980Al.sub.x Ga.sub.1-x As Visible to Infrared 870-650Zn-doped Visible 650Al.sub.0.4 Ga.sub.0.6 AsSi-doped Commercial 870-890Al.sub.0.3 Ga.sub.0.7 As Infrared DiodesGaP Visible non-radiative recombinationGaAs.sub.1-x P.sub.x Visible 870-620GaAs.sub.0.6 P.sub.0.4 Commercial Red 630-660GaP doped with ZnO Red 690N-doped Commercial Red 630GaAs.sub.0.35 P.sub.0.65N-doped Commercial Yellow 585GaAs.sub.0.15 P.sub.0.85N-doped GaP Commercial Green 565In.sub.x Ga.sub.1-x As.sub.y P.sub.1-y Infrared 900-2550In.sub.0.18 Ga.sub.0.82 As Commercial 1064 Infrared DiodesIn.sub.0.74 Ga.sub.0.26 As.sub.0.56 P.sub.0.44 Commercial 1300 Infrared DiodesIn.sub.0.61 Ga.sub.0.39 As.sub.0.85 P.sub.0.15 Commercial 1550 Infrared DiodesInGaAsSb/AlGaAsSb Mid Infrared 2270InGaAsSb Infrared to 1800-4400 Mid infraredIn.sub.0.53 Ga.sub.0.47 As Infrared 1670In.sub.0.8 Ga.sub.0.2 As Infrared 2550SiC Visible Blue 470Cd.sub.x Hg.sub.1-x Te Mid Infrared 3000-15000Cd.sub.x Hg.sub.1-x Se Mid Infrared 3000-15000Pb.sub.x S.sub.1-x Se Mid Infrared 5000-9000Pb.sub.x Sn.sub.1-x Te Mid Infrared 7000-40000Pb.sub.x Sn.sub.1-x Se Mid Infrared 9000-40000______________________________________
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A spectrophotometer includes an array of light emitting diodes configured for activation in successive Hadamard encodement patterns, a diffraction grating, an optical slit, a detector and electronic controls including a computer. In operation, the diffraction grating disperses and collimates radiation from the array and directs selected spectral components through the slit onto the detector whereupon the computer performs a Hadamard analysis on the detector signals.
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[0001] This application is a continuation-in-part of U.S. application Ser. No. 10/222,454, filed Aug. 16, 2002, which is a divisional of U.S. application Ser. No. 09/874,391, filed Jun. 4, 2001, now abandoned. The above two identified applications are incorporated herein by reference in their entirety.
BACKGROUND
[0002] The electrophoretic display (EPD) is a non-emissive device based on the electrophoresis phenomenon influencing charged pigment particles suspended in a solvent. This general type of display was first proposed in 1969. An EPD typically comprises a pair of opposed, spaced-apart plate-like electrodes, with spacers predetermining a certain distance between the electrodes. One of the electrodes is typically transparent. A suspension composed of a colored solvent and suspended charged pigment particles is enclosed between the two plates.
[0003] When a voltage difference is imposed between the two electrodes, the pigment particles migrate by attraction to the plate of polarity opposite that of the pigment particles. Thus the color showing at the transparent plate may be determined by selectively charging the plates to be either the color of the solvent or the color of the pigment particles. Reversal of plate polarity will cause the particles to migrate back to the opposite plate, thereby reversing the color. Intermediate color density (or shades of gray) due to intermediate pigment density at the transparent plate may be obtained by controlling the voltage or charging time.
[0004] Among the advantages of an electrophoretic display (EPD) over other types of flat panel displays is the very low power consumption. This salient advantage makes EPDs particularly suitable for portable and battery powered devices such as laptops, cell phones, personal digital assistants, portable electronic medical and diagnostic devices, global positioning system devices, and the like.
[0005] In order to prevent undesired movements of the particles such as sedimentation, partitions were proposed between the two electrodes for dividing the space into smaller cells. See, e.g., M. A Hopper and V. Novotny, IEEE Trans. Electr. Dev., Vol ED 26, No. 8, pp 1148-1152 (1979). However, in the case of the partition-type EPD, some difficulties are encountered in the formation of the partitions and the process of enclosing the suspension. Furthermore, it is also difficult to keep suspensions of different colors separate from each other in the partition-type EPD.
[0006] Attempts have been made to enclose the suspension in microcapsules. U.S. Pat. Nos. 5,961,804 and 5,930,026 describe microencapsulated EPDs. These displays have a substantially two dimensional arrangement of microcapsules each containing an electrophoretic composition comprising a dielectric fluid with charged pigment particles suspended therein and the particles visually contrast with the dielectric solvent. The microcapsules can be formed by interfacial polymerization, in-situ polymerization or other known methods such as in-liquid curing or simple/complex coacervation. The microcapsules, after their formation, may be injected into a cell housing two spaced-apart electrodes, or they may be “printed” onto or coated on a transparent conductor film. The microcapsules may also be immobilized within a transparent matrix or binder that is itself sandwiched between the two electrodes.
[0007] The EPDs prepared by these prior art processes, in particular the microencapsulation process, as disclosed in U.S. Pat. Nos. 5,930,026, 5,961,804 and 6,017,584, have several shortcomings. For example, the EPDs manufactured by the microencapsulation process suffer from sensitivity to environmental changes (in particular sensitivity to moisture and temperature) due to the wall chemistry of the microcapsules. Secondly, the EPDs based on the microcapsules have poor scratch resistance due to the thin wall and large particle size of the microcapsules. To improve the handleability of the display, microcapsules are embedded in a large quantity of polymer matrix which results in a slow response time due to the large distance between the two electrodes and a low contrast ratio due to the low payload of pigment particles. It is also difficult to increase the surface charge density on the pigment particles because charge-controlling agents tend to diffuse to the water/oil interface during the microencapsulation process. The low charge density or zeta potential of the pigment particles in the microcapsules also results in a slow response rate. Furthermore, because of the large particle size and broad size distribution of the microcapsules, the prior art EPD of this type has poor resolution and addressability for color applications.
[0008] Recently an improved EPD technology was disclosed in U.S. Pat. Nos. 6,930,818 and 6,933,098. The cells of the improved EPD are formed from a plurality of microcups which are formed integrally with one another as portions of a structured two-dimensional array assembly. Each microcup of the array assembly is filled with a suspension or dispersion of charged pigment particles in a dielectric solvent, and sealed to form an electrophoretic cell.
[0009] The substrate web upon which the microcups are formed includes a display addressing array comprising a pre-formed conductor film, such as ITO conductor lines. The conductor film (ITO lines) is coated with a radiation curable polymer precursor layer. The film and precursor layer are then exposed imagewise to radiation to form the microcup wall structure. Following exposure, the precursor material is removed from the unexposed areas, leaving the cured microcup walls bonded to the conductor film/support web. The imagewise exposure may be accomplished by UV or other forms of radiation through a photomask to produce an image or predetermined pattern of exposure of the radiation curable material coated on the conductor film. Although it is generally not required, the mask may be positioned and aligned with respect to the conductor film, i.e., ITO lines, so that the transparent mask portions align with the spaces between ITO lines, and the opaque mask portions align with the ITO material (intended for microcup cell floor areas).
[0010] Alternatively, the microcup array may be prepared by a process including embossing a thermoplastic or thermoset precursor layer coated on a conductor film with a pre-patterned male mold, followed by releasing the mold. The precursor layer may be hardened by radiation, cooling, solvent evaporation, or other means during or after the embossing step. This novel micro-embossing method is disclosed in U.S. Pat. No. 6,630,818.
[0011] Solvent-resistant, thermomechanically stable microcups having a wide range of size, shape, pattern and opening ratio can be prepared by either one of the aforesaid methods.
[0012] The manufacture of a monochrome EPD from a microcup assembly involves filling the microcups with a single pigment suspension composition, sealing the microcups, and finally laminating the sealed array of microcups with a second conductor film pre-coated with an adhesive layer.
[0013] For a color EPD, its preparation from a microcup assembly involves sequential selective opening and filling of predetermined microcup subsets. The process includes laminating or coating the pre-formed microcups with a layer of positively working photoresist, selectively opening a certain number of the microcups by imagewise exposing the positive photoresist, followed by developing the photoresist, filling the opened microcups with a colored electrophoretic fluid, and sealing the filled microcups by a sealing process. These steps may be repeated to create sealed microcups filled with electrophoretic fluids of different colors. Thus, the array may be filled with different colored compositions in predetermined areas to form a color EPD. Various known pigments and dyes provide a wide range of color options for both solvent phase and suspended particles. Known fluid application and filling mechanisms may be employed.
[0014] The sealing of the microcups after they are filled with a dispersion of charged pigment particles in a dielectric fluid can be accomplished by overcoating the electrophoretic fluid with a solution containing a thermoplastic or thermoset precursor. To reduce or eliminate the degree of intermixing during and after the overcoating process, it is highly advantageous to use a sealing composition that is immiscible with the electrophoretic fluid and preferably has a specific gravity lower than the electrophoretic fluid. The sealing is then accomplished by hardening the sealing composition by solvent evaporation, interfacial reaction, moisture, heat, radiation, or a combination of curing mechanisms. Alternatively, the sealing can be accomplished by dispersing a thermoplastic or thermoset precursor in the electrophoretic fluid before the filling step. The thermoplastic or thermoset precursor is immiscible with the dielectric solvent and has a specific gravity lower than that of the solvent and the pigment particles. After filling, the thermoplastic or thermoset precursor phase separates from the electrophoretic fluid and forms a supernatant layer at the top of the fluid. The sealing of the microcups is then conveniently accomplished by hardening the precursor layer by solvent evaporation, interfacial reaction, moisture, heat, or radiation. UV radiation is the preferred method to seal the microcups, although a combination of two or more curing mechanisms as described above may be used to increase the throughput of sealing.
[0015] The improved EPDs may also be manufactured by a synchronized roll-to-roll photolithographic exposure process as described in U.S. Pat. No. 6,933,098. A photomask may be synchronized in motion with the support web using mechanisms such as coupling or feedback circuitry or common drives to maintain the coordinated motion (i.e., to move at the same speed). Following exposure, the web moves into a development area where the unexposed material is removed to form the microcup wall structure. The microcups and ITO lines are preferably of selected size and coordinately aligned with the photomask, so that each completed display cell (i.e., filled and sealed microcup) may be discretely addressed and controlled by the display driver. The ITO lines may be pre-formed by either a wet or a dry etching process on the substrate web.
[0016] For making color displays from the microcup array, the synchronized roll-to-roll exposure photolithographic process also enables continuous web processes of selective opening, filling and sealing of pre-selected subsets of the microcup array.
[0017] The microcup array may be temporarily sealed by laminating or coating with a positive-acting photoresist composition, imagewise exposing through a corresponding photomask, and developing the exposed area with a developer to selectively open a desired subset of the microcups. Known laminating and coating mechanisms may be employed. The term “developer” in this context refers to a suitable known means for selectively removing the exposed photoresist, while leaving the unexposed photoresist in place.
[0018] Thus, the array may be sequentially filled with several different color compositions (typically three primary colors) in a pre-determined cell pattern. For example, the imagewise exposure process may employ a positively working photoresist top laminate or coating which initially seals the empty microcups. The microcups are then exposed through a mask (e.g., a loop photomask in the described roll-to-roll process) so that only a first selected subset of microcups are exposed. Development with a developer removes the exposed photoresist and thus opens the first microcup subset to permit filling with a selected color pigment dispersion composition, and sealing by one of the methods described herein. The exposure and development process is repeated to expose and open a second selected microcup subset, for filling with a second pigment dispersion composition, with subsequent sealing. Finally, the remaining photoresist is removed and the third subset of microcups is filled and sealed.
[0019] Liquid crystal displays (LCDs) may also be prepared by the method as described above when the electrophoretic fluid is replaced by a suitable liquid crystal composition having the ordinary refractive index matched to that of the isotropic microcup material. In the “on” state, the liquid crystal in the microcups is aligned to the field direction and is transparent. In the “off” state, the liquid crystal is not aligned and scatters light. To maximize the light scattering effect of the LCDs, the diameter of the microcups is typically in the range of 0.5-10 microns.
[0020] The roll-to-roll process may be employed to carry out a sequence of processes on a single continuous web, by carrying and guiding the web to a plurality of process stations in sequence. In other words, the microcups may be formed, filled or coated, developed, sealed, and laminated in a continuous sequence.
[0021] In addition to the manufacture of microcup displays, the synchronized roll-to-roll process may be adapted to the preparation of a wide range of structures or discrete patterns for electronic devices formable upon a support web substrate, e.g., patterned conductor films, flexible circuit boards and the like. As in the process and apparatus for EPD microcups described herein, a pre-patterned photomask is prepared which includes a plurality of photomask portions corresponding to structural elements of the subject device. Each such photomask portion may have a pre-selected area of transparency or opacity to radiation so as to form an image of such a structural element upon the correspondingly aligned portion of the web during exposure. The method may be used for selective curing of structural material, or may be used to expose positively or negatively acting photoresist material during manufacturing processes.
[0022] Because these multiple-step processes may be carried out roll-to-roll continuously or semi-continuously, they are suitable for high volume and low cost production. These processes are also efficient and inexpensive as compared to other processes for manufacturing display products. The improved EPD involving microcups is not sensitive to environment, such as humidity and temperature. The display is thin, flexible, durable, easy-to-handle, and format-flexible. Since the EPD comprises cells of favorable aspect ratio and well-defined shape and size, the bi-stable reflective display has excellent color addressability, high contrast ratio and color saturation, fast switching rate and response time.
SUMMARY OF THE INVENTION
[0023] Sealing of the microcups by a continuous web process is one of the most critical steps in the roll-to-roll manufacturing of the improved EPDs. In order to prepare a high quality display, the sealing layer must have at least the following characteristics: (1) free of defects such as entrapped air bubble, pin holes, cracking or leaking, etc; (2) good film integrity and barrier properties against the display fluid such as dielectric fluids for EPDs; and (3) good coating and adhesion properties. Since most of the dielectric solvents used in EPDs are of low surface tension and low viscosity, it has been a major challenge to achieve a seamless, defect-free sealing with good adhesion properties for the microcups.
[0024] It has now been found that microcups filled with a display fluid such as an electrophoretic fluid can be sealed seamlessly and free of defects by a continuous web process using a novel sealing composition comprising the following ingredients:
(1) a solvent or solvent mixture which is immiscible with the display fluid in the microcups, and preferably exhibits a specific gravity equal to or less than that of the display fluid; and (2) a thermoplastic elastomer.
[0027] Compositions containing at least a thermoplastic elastomer having good compatibility with the microcups and good barrier properties against the display fluid are particularly useful. Examples of useful thermoplastic elastomers include di-block, tri-block or multi-block copolymers represented by the formulas ABA or (AB)n in which A is styrene, α-methylstyrene, ethylene, propylene or norbornene; B is butadiene, isoprene, ethylene, proplyene, butylene, dimethylsiloxane or propylene sulfide; and A and B cannot be the same in the formula. The number, n, is ≧1, preferably 1-10. Representative copolymers include poly(styrene-b-butadiene), poly(styrene-b-butadiene-b-styrene), poly(styrene-b-isoprene-b-styrene), poly(styrene-b-ethylene/butylene-b-styrene), poly(styrene-b-dimethylsiloxane-b-styrene), poly((α-methylstyrene-b-isoprene), poly(α-methylstyrene-b-isoprene-b-α-methylstyrene), poly(α-methylstyrene-b-propylene sulfide-b-α-methylstyrene), and poly(α-methylstyrene-b-dimethylsiloxane-b-α-methylstyrene). A review of the preparation of the thermoplastic elastomers can be found in N. R. Legge, G. Holden, and H. E. Schroeder ed., “Thermoplastic Elastomers”, Hanser Publisher (1987). Commercially available styrene block copolymers such as Kraton D and G series from Shell Chemical Company are particularly useful. Crystalline rubbers such as poly(ethylene-co-propylene-co-5-methylene-2-norbornene) or EPDM (ethylene-propylene-diene terpolymer) rubbers and their grafted copolymers have also been found very useful. Not to be bound by the theory, it is believed that the hard block of the thermoplastic elastomers phase separates during or after the drying of the sealing composition and serves as the physical crosslinker of the soft continuous phase. The sealing composition of the present invention significantly enhances the modulus and film integrity of the sealing layer throughout the coating and drying processes. Thermoplastic elastomers having low critical surface tension (lower than 40 dyne/cm) and high modulus or Shore A hardness (higher than 60) have been found useful probably because of their favorable wetting property and film integrity over the display fluid.
[0028] The thermoplastic elastomer is dissolved in a solvent or solvent mixture which is immiscible with the display fluid in the microcups and exhibits a specific gravity equal to or less than that of the display fluid. Low surface tension solvents are preferred for the sealing composition because of their better wetting properties over the microcup surface and the display fluid. Solvents or solvent mixtures having a surface tension lower than 35 dyne/cm are preferred. A surface tension lower than 30 dyne/cm is more preferred. Suitable solvents include alkanes (preferably C 6-12 alkanes such as heptane, octane or Isopar solvents from Exxon Chemical Company, nonane, decane and their isomers), cycloalkanes (preferably C 6-12 cycloalkanes such as cyclohexane, decalin and the like), alkylbenzenes (preferably mono- or di-C 1-6 alkyl benzenes such as toluene, xylene and the like), alkyl esters (preferably C 2-5 alkyl esters such as ethyl acetate, isobutyl acetate and the like) and C 3-5 alkyl alcohols (such as isopropanol and the like) and their isomers.
[0029] In addition to the fact that the display cells prepared from microcups may be sealed seamlessly and free of defects by a continuous web process using this novel sealing composition, the sealing composition also has many other advantages. For example, it also exhibits good wetting properties over the filled microcups throughout the coating process and develops a good film integrity over the display fluid even before the solvent evaporates completely. As a result, the integrity of the coating is maintained and no dewetting or beading on the display fluid is observed. In addition, the composition of the present invention enables the continuous sealing of wider microcups, particularly those having a width greater than 100 microns. Wider microcups are preferred in some applications because of their higher microcup opening-to-wall ratio and better display contrast ratio. Furthermore, the sealing composition of the present invention enables the formation of a sealing layer less than 3 microns thick which is typically difficult to achieve by using traditional sealing compositions. The thinner sealing layer shortens the distance between the top and bottom electrodes and results in a faster switching rate.
[0030] Co-solvents and wetting agents may also be included in the sealing composition to improve the adhesion of the sealing layer to the microcups and provides a wider coating process latitude. Other ingredients such as crosslinking agents, vulcanizers, multifunctional monomers or oligomers, and high Tg polymers that are miscible with one of the blocks of the thermoplastic elastomer are also highly useful to enhance the physicomechanical properties of the sealing layer during or after the sealing process. The sealed microcups may be post treated by UV radiation or thermal baking to further improve the barrier properties. The adhesion of the sealing layer to the microcups may also be improved by the post-curing reaction, probably due to the formation of an interpenetration network at the microcup-sealing layer inter-phase.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a schematic cross-section of an EPD, showing three microcup cells in a neutral condition.
[0032] FIG. 2 is a schematic cross-section of the EPD of FIG. 1 , but with two of the cells charged, to cause the pigment to migrate to one plate.
[0033] FIGS. 3A-3C shows the contours of an exemplary microcup array, FIG. 3A showing a perspective view, FIG. 3B showing a plan view, and FIG. 3C showing an elevation view, the vertical scale being exaggerated for clarity.
[0034] FIGS. 4A and 4B show the basic processing steps for preparing the microcups involving imagewise photolithographic exposure through a photomask (“top exposure”) of the conductor film coated with a thermoset precursor, to UV radiation.
[0035] FIGS. 5A and 5B show alternative processing steps for preparing the microcups involving imagewise photolithography combining the top exposure and bottom exposure principles, whereby the walls are cured in one lateral direction by top photomask exposure and in the perpendicular lateral direction by bottom exposure through the opaque base conductor film (“combined exposure”).
[0036] FIGS. 6A-6D are a sequence of cross sections of a microcup array, illustrating the steps of assembling a monochrome display.
DETAILED DESCRIPTION OF THE INVENTION
[0000] I. Definitions
[0037] Unless defined otherwise in this specification, all technical terms are used herein according to their conventional definitions as they are commonly used and understood by those of ordinary skill in the art.
[0038] The term “microcup” refers to the cup-like indentations, which may be created by methods such as micro-embossing or imagewise exposure as described in the patents identified above. Likewise, the plural form “microcups” in a collective context may in general refer to the microcup assembly comprising a plurality of such microcups integrally formed or joined to make a structured two-dimensional microcup array.
[0039] The term “cell”, in the context of the present invention, is intended to mean the single unit formed from a sealed microcup. The cells are filled with charged pigment particles dispersed in a solvent or solvent mixture.
[0040] The term “well-defined”, when describing the microcups or cells, is intended to indicate that the microcup or cell has a definite shape, size, pattern and aspect ratio which are pre-determined according to the specific parameters of the manufacturing process.
[0041] The term “aspect ratio” is a commonly known term in the art and is the depth to width ratio or the depth to diameter ratio of the microcup opening.
[0042] The term “imagewise exposure” means exposure of radiation-curable material or photoresist composition to radiation, such as UV, using one of the methods of the invention, whereby the portions of the material so exposed are controlled to form a pattern or “image” corresponding to the structure of the microcups, e.g., the exposure is restricted to the portions of the material corresponding to the microcup walls, leaving the microcup floor portion unexposed. In the case of selectively opening photoresist on predetermined portions of the microcup array, imagewise exposure means exposure on the portions of material corresponding to the microcup opening, leaving the microcup walls unexposed. The pattern or image may be formed by such methods as exposure through a photomask, or alternatively by controlled particle beam exposure, and the like.
[0000] II. The Microcup Array
[0043] FIGS. 1 and 2 are schematic cross-section views of an exemplary microcup array assembly embodiment, simplified for clarity, showing a microcup array assembly ( 10 ) of three microcup cells ( 12 a, b , and c ).
[0044] As shown in FIG. 1 , each cell ( 12 ) of array ( 10 ) comprises two electrode plates ( 11 , 13 ), at least one of which is transparent ( 11 ), such as an ITO electrode, the electrodes ( 11 ) and ( 13 ) bounding two opposite faces of the cell ( 12 ).
[0045] The microcup cell array assembly ( 10 ) comprises a plurality of cells which are disposed adjacent to one another within a plane to form a layer of cells ( 12 ) enclosed between the two electrodes layers ( 11 ) and ( 13 ). Three exemplary cells ( 12 a ), ( 12 b ), and ( 12 c ) are shown, bounded by their respective electrode plates ( 11 a ), ( 11 b ), and ( 11 c ) (transparent) and ( 13 a ), ( 13 b ), and ( 13 c ) (back plates), it being understood that a large number of such cells are preferably arrayed two-dimensionally (to the right/left and in/out of the plane in FIG. 1 ) to form a sheet-like display of any selected area and two-dimensional shape. Likewise, several microcup cells may be bounded by a single electrode plate ( 11 ) or ( 13 ), although, for clarity, FIG. 1 shows an example in which each cell ( 12 ) is bounded by separate electrode plates ( 11 ) and ( 13 ) having the width of a single cell.
[0046] The cells are of well-defined shape and size and are filled with a colored dielectric solvent ( 14 ) in which charged pigment particles ( 15 ) are suspended and dispersed. The cells ( 12 ) may be each filled with the same composition of pigment and solvent (e.g., in a monochrome display) or may be filled with different compositions of pigment and solvent (e.g., in a color display). FIG. 1 shows three different color combinations as indicated by the different hatch pattern in each cell ( 12 a ), ( 12 b ), and ( 12 c ), the solvents being designated ( 14 a ), ( 14 b ), and ( 14 c ) respectively, and the pigment particles being designated ( 15 a ), ( 15 b ), and ( 15 c ) respectively.
[0047] The microcup cells ( 12 ) each comprise enclosing walls ( 16 ) bounding the cells on the sides (within the plane of array ( 10 )) and floor ( 17 ) bounding the cell on one face, in this example, the face adjacent to electrode ( 13 ). On the opposite face (adjacent electrode ( 11 )) each cell comprises sealing cap portion ( 18 ). Where the sealing cap portion is adjacent to the transparent electrode ( 11 ) (as in FIG. 1 ), the sealing cap ( 18 ) comprises a transparent composition. Although in the example of FIG. 1 , the floor ( 17 ) and the sealing cap ( 18 ) are shown as separate cell portions distinct from adjacent electrodes ( 13 ) and ( 11 ) respectively, alternative embodiments of the microcup array ( 10 ) of the invention may comprise an integral floor/electrode structure or an integral sealing cap/electrode structure.
[0048] FIG. 2 is a schematic cross-section of the EPD of FIG. 1 , but with two of the cells charged ( 12 a and 12 c ), to cause the pigment to migrate to one plate. When a voltage difference is imposed between the two electrodes ( 11 , 13 ), the charged particles ( 15 ) migrate (i.e., toward electrode ( 11 ) or ( 13 ) depending on the charge of the particle and electrode), such that either the color of the pigment particle ( 15 ) or the color of the solvent ( 14 ) is seen through the transparent conductor film ( 11 ). At least one of the two conductors ( 11 ) or ( 13 ) is patterned (separately addressable portions) to permit a selective electric field to be established with respect to either each cell or with respect to a pre-defined group of cells (e.g., to form a pixel).
[0049] In the example of FIG. 2 , two of the cells are shown charged ( 12 a and 12 c ), in which the pigment ( 15 a and 15 c ) has migrated to the respective transparent electrode plates ( 11 a and 11 c ). The remaining cell ( 12 b ) remains neutral and pigment ( 15 b ) is dispersed throughout solvent ( 14 b ).
[0050] FIGS. 3A-3C shows the contours of an exemplary portion of a microcup array, FIG. 3A showing a perspective view, FIG. 3B showing a plan view, and FIG. 3C showing an elevation view, the vertical scale being exaggerated for clarity. For reflective EPDs, the opening area of each individual microcup may preferably be in the range of about 10 2 to about 5×10 5 μm 2 , more preferably from about 10 3 to about 5×10 4 μm 2 . The width w of the microcup ( 12 ) (distance between adjacent walls ( 16 )) may vary over a wide range, and is selectable to suit the desired final display characteristics. The width w of the microcup openings preferably is in the range of from about 15 to about 450 μm, and more preferably from about 25 to about 300 μm from edge to edge of the openings. Each microcup may form a small segment of a pixel of the final display, or may be a full pixel.
[0051] The wall thickness t relative to the microcup width w may vary over a large range, and is selectable to suit the desired final display characteristics. The microcup wall thickness is typically from about 0.01 to about 1 times the microcup width, and more preferably about 0.05 to about 0.25 times the microcup width. The opening-to-total area ratio is preferably in the range of about 0.1 to about 0.98, more preferably from about 0.3 to about 0.95.
[0052] The microcup wall height h (which defines the microcup depth) is shown exaggerated beyond its typical proportional dimensions for clarity. For EPDs, the height of the microcups is typically in the range of about 5 to about 100 microns (μms), preferably from about 10 to about 50 microns. For LCDs, the height is typically in the range of about 1 to 10 microns and more preferably from about 2 to 5 microns.
[0053] For simplicity and clarity, a square microcup arranged in a linear two-dimensional array assembly is assumed in the description herein of the microcup array assembly of the invention. However, the microcup need not be square, it may be rectangular, circular, or a more complex shape if desired. For example, the microcups may be hexagonal and arranged in a hexagonal close-packed array, or alternatively, triangular microcups may be oriented to form hexagonal sub-arrays, which in turn are arranged in a hexagonal close-packed array.
[0054] In general, the microcups can be of any shape, and their sizes, pattern and shapes may vary throughout the display. This may be advantageous in the color EPD. In order to maximize the optical effect, microcups having a mixture of different shapes and sizes may be produced. For example, microcups filled with a dispersion of the red color may have a different shape or size from the green microcups or the blue microcups. Furthermore, a pixel may consist of different numbers of microcups of different colors. For example, a pixel may consist of a number of small green microcups, a number of large red microcups, and a number of small blue microcups. It is not necessary to have the same shape and number for the three colors.
[0055] The openings of the microcups may be round, square, rectangular, hexagonal, or any other shapes. The partition area between the openings is preferably kept small in order to achieve a high color saturation and contrast while maintaining desirable mechanical properties. Consequently the honeycomb-shaped opening is preferred over, for example, the circular opening.
[0000] III. Preparation of the Microcup Array
[0056] The microcups may be prepared by microembossing or by photolithography.
[0000] IIIa. Preparation of Microcups Array by Microembossing
[0057] Preparation of the Male Mold
[0058] The male mold may be prepared by any appropriate method, such as a diamond turn process or a photoresist process followed by either etching or electroplating. A master template for the male mold may be manufactured by any appropriate method, such as electroplating. With electroplating, a glass base is sputtered with a thin layer (typically 3000 Å) of a seed metal such as chrome inconel. It is then coated with a layer of photoresist and exposed to UV. A mask is placed between the UV and the layer of photoresist. The exposed areas of the photoresist become hardened. The unexposed areas are then removed by washing them with an appropriate solvent. The remaining hardened photoresist is dried and sputtered again with a thin layer of seed metal. The master is then ready for electroforming. A typical material used for electroforming is nickel cobalt. Alternatively, the master can be made of nickel by electroforming or electroless nickel deposition as described in “Continuous manufacturing of thin cover sheet optical media”, SPIE Proc. Vol. 1663, pp. 324 (1992). The floor of the mold is typically between about 50 to 400 microns. The master can also be made using other microengineering techniques including e-beam writing, dry etching, chemical etching, laser writing or laser interference as described in “Replication techniques for micro-optics”, SPIE Proc. Vol. 3099, pp. 76-82 (1997). Alternatively, the mold can be made by photomachining using plastics, ceramics or metals.
[0059] The male mold thus prepared typically has protrusions between about 1 to 500 microns, preferably between about 2 to 100 microns, and most preferred about 4 to 50 microns. The male mold may be in the form of a belt, a roller, or a sheet. For continuous manufacturing, the belt type of mold is preferred.
[0060] Microcup Formation
[0061] Microcups may be formed either in a batchwise process or in a continuous roll-to-roll process as disclosed in U.S. Pat. No. 6,933,098. The latter offers a continuous, low cost, high throughput manufacturing technology for production of compartments for use in electrophoretic or LCDs. Prior to applying a UV curable resin composition, the mold may be treated with a mold release to aid in the demolding process. The UV curable resin may be degassed prior to dispensing and may optionally contain a solvent. The solvent, if present, readily evaporates. The UV curable resin is dispensed by any appropriate means such as, coating, dipping, pouring or the like, over the male mold. The dispenser may be moving or stationary. A conductor film is overlaid the UV curable resin. Examples of suitable conductor film include transparent conductor ITO on plastic substrates such as polyethylene terephthalate, polyethylene naphthalate, polyaramid, polyimide, polycycloolefin, polysulfone, epoxy and their composites. Pressure may be applied, if necessary, to ensure proper bonding between the resin and the plastic and to control the thickness of the floor of the microcups. The pressure may be applied using a laminating roller, vacuum molding, press device or any other like means. If the male mold is metallic and opaque, the plastic substrate is typically transparent to the actinic radiation used to cure the resin. Conversely, the male mold can be transparent and the plastic substrate can be opaque to the actinic radiation. To obtain good transfer of the molded features onto the transfer sheet, the conductor film needs to have good adhesion to the UV curable resin which should have a good release property against the mold surface.
[0000] IIIb. Preparation of Microcup Array by Photolithography
[0062] The photolithographic processes for preparation of the microcup array are described in FIGS. 4 and 5 .
[0063] Top Exposure
[0064] As shown in FIGS. 4A and 4B , the microcup array ( 40 ) may be prepared by exposure of a radiation curable material ( 41 a ) coated by known methods onto a conductor electrode film ( 42 ) to UV light (or alternatively other forms of radiation, electron beams and the like) through a mask ( 46 ) to form walls ( 41 b ) corresponding to the image projected through the mask ( 46 ). The base conductor film ( 42 ) is preferably mounted on a supportive substrate base web ( 43 ), which may comprise a plastic material.
[0065] In the photomask ( 46 ) in FIG. 4A , the dark squares ( 44 ) represent the opaque area and the space between the dark squares represents the transparent area ( 45 ) of the mask ( 46 ). The UV radiates through the transparent area ( 45 ) onto the radiation curable material ( 41 a ). The exposure is preferably performed directly onto the radiation curable material ( 41 a ), i.e., the UV does not pass through the substrate ( 43 ) or base conductor ( 42 ) (top exposure). For this reason, neither the substrate ( 43 ) nor the conductor ( 42 ) needs to be transparent to the UV or other radiation wavelengths employed.
[0066] As shown in FIG. 4B , the exposed areas ( 41 b ) become hardened and the unexposed areas (protected by the opaque area ( 44 ) of the mask ( 46 )) are then removed by an appropriate solvent or developer to form the microcups ( 47 ). The solvent or developer is selected from those commonly used for dissolving or reducing the viscosity of radiation curable materials such as methylethylketone (MEK), toluene, acetone, isopropanol or the like. The preparation of the microcups may be similarly accomplished by placing a photomask underneath the conductor film/substrate support web and in this case the UV light radiates through the photomask from the bottom and the substrate needs to be transparent to radiation.
[0067] Exposure Through Opaque Conductor Lines
[0068] Still another alternative method for the preparation of the microcup array of the invention by imagewise exposure is illustrated in FIGS. 5A and 5B . When opaque conductor lines are used, the conductor lines can be used as the photomask for the exposure from the bottom. Durable microcup walls are formed by additional exposure from the top through a second photomask having opaque lines perpendicular to the conductor lines.
[0069] FIG. 5A illustrates the use of both the top and bottom exposure principles to produce the microcup array ( 50 ) of the invention. The base conductor film ( 52 ) is opaque and line-patterned. The radiation curable material ( 51 a ), which is coated on the base conductor ( 52 ) and substrate ( 53 ), is exposed from the bottom through the conductor line pattern ( 52 ) which serves as the first photomask. A second exposure is performed from the “top” side through the second photomask ( 56 ) having a line pattern perpendicular to the conductor lines ( 52 ). The spaces ( 55 ) between the lines ( 54 ) are substantially transparent to the UV light. In this process, the wall material ( 51 b ) is cured from the bottom up in one lateral orientation, and cured from the top down in the perpendicular direction, joining to form an integral microcup ( 57 ).
[0070] As shown in FIG. 5B , the unexposed area is then removed by a solvent or developer as described above to reveal the microcups ( 57 ).
[0000] IV. The Sealing Composition and Process of the Present Invention
[0071] The novel sealing composition comprises the following ingredients:
[0072] (1) a solvent or solvent mixture which is immiscible with the display fluid in the microcups, and preferably exhibits a specific gravity equal to or less than that of the display fluid; and
[0073] (2) a thermoplastic elastomer.
[0074] Compositions containing a thermoplastic elastomer having good compatibility with the microcups and good barrier properties against the display fluid are particularly useful. Examples of useful thermoplastic elastomers include ABA, and (AB)n type of di-block, tri-block, and multi-block copolymers wherein A is styrene, α-methylstyrene, ethylene, propylene or norbornene; B is butadiene, isoprene, ethylene, propylene, butylene, dimethylsiloxane or propylene sulfide; and A and B cannot be the same in the formula. The number, n, is ≧1, preferably 1-10. Particularly useful are di-block or tri-block copolymers of styrene or α-methylstyrene such as SB (poly(styrene-b-butadiene)), SBS (poly(styrene-b-butadiene-b-styrene)), SIS (poly(styrene-b-isoprene-b-styrene)), SEBS (poly(styrene-b-ethylene/butylenes-b-styrene)) poly(styrene-b-dimethylsiloxane-b-styrene), poly((α-methylstyrene-b-isoprene), poly(α-methylstyrene-b-isoprene-b-α-methylstyrene), poly(α-methylstyrene-b-propylene sulfide-b-α-methylstyrene), poly(α-methylstyrene-b-dimethylsiloxane-b-α-methylstyrene). A review of the preparation of the thermoplastic elastomers can be found in N. R. Legge, G. Holden, and H. E. Schroeder ed., “Thermoplastic Elastomers”, Hanser Publisher (1987). Commercially available styrene block copolymers such as Kraton D and G series (from Kraton Polymer, Houston, Tex.) are particularly useful. Crystalline rubbers such as poly(ethylene-co-propylene-co-5-methylene-2-norbornene) or EPDM (ethylene-propylene-diene terpolymer) rubbers such as Vistalon 6505 (from Exxon Mobil, Houston, Tex.) and their grafted copolymers have also been found very useful.
[0075] Not to be bound by the theory, it is believed that the hard block of the thermoplastic elastomers phase separates during or after the drying of the sealing composition and serves as the physical crosslinker of the soft continuous phase. The sealing composition of the present invention significantly enhances the modulus and film integrity of the sealing layer throughout the coating and drying processes of the sealing layer. Thermoplastic elastomers having low critical surface tension (lower than 40 dyne/cm) and high modulus or Shore A hardness (higher than 60) have been found useful probably because of their favorable wetting property and film integrity over the display fluid.
[0076] The thermoplastic elastomer is dissolved in a solvent or solvent mixture which is immiscible with the display fluid in the microcups and exhibits a specific gravity less than that of the display fluid. Low surface tension solvents are preferred for the sealing composition because of their better wetting properties over the microcup walls and the display fluid. Solvents or solvent mixtures having a surface tension lower than 35 dyne/cm are preferred. A surface tension of lower than 30 dyne/cm is more preferred. Suitable solvents include alkanes (preferably C 6-12 alkanes such as heptane, octane or Isopar solvents from Exxon Chemical Company, nonane, decane and their isomers), cycloalkanes (preferably C 6-12 cycloalkanes such as cyclohexane and decalin and the like), alkylbenzenes (preferably mono- or di-C 1-6 alkyl benzenes such as toluene, xylene and the like), alkyl esters (preferably C 2-5 alkyl esters such as ethyl acetate, isobutyl acetate and the like) and C 3-5 alkyl alcohols (such as isopropanol and the like) and their isomers. Mixtures of alkylbenzene and alkane are particularly useful.
[0077] Wetting agents (such as the FC surfactants from 3M Company, Zonyl fluorosurfactants from DuPont, fluoroacrylates, fluoromethacrylates, fluoro-substituted long chain alcohols, perfluoro-substituted long chain carboxylic acids and their derivatives, and Silwet silicone surfactants from OSi, Greenwich, Conn.) may also be included in the composition to improve the adhesion of the sealing layer to the microcups and provide a more flexible coating process. Other ingredients including crosslinking agents (e.g., bisazides such as 4,4′-diazidodiphenylmethane and 2,6-di-(4′-azidobenzal)-4-methylcyclohexanone), vulcanizers (e.g., 2-benzothiazolyl disulfide and tetramethylthiuram disulfide), multifunctional monomers or oligomers (e.g., hexanediol, diacrylates, trimethylolpropane, triacrylate, divinylbenzene, diallylnaphthalene), thermal initiators (e.g., dilauroyl peroxide, benzoyl peroxide) and photoinitiators (e.g., isopropyl thioxanthone (ITX), Irgacure 651 and Irgacure 369 from Ciba-Geigy) are also highly useful to enhance the physicomechanical properties of the sealing layer by crosslinking or polymerization reactions during or after the sealing process.
[0078] The sealing composition may be overcoated onto microcups partially filled with a display fluid and a sealing layer is formed by drying the sealing composition when it is on top of the display fluid. The sealed microcups optionally may be post treated by UV radiation or thermal baking to further improve the barrier properties. The adhesion of the sealing layer to the microcups may also be improved by the post-curing reaction, likely due to the formation of an interpenetration network at the microcup-sealing layer inter-phase.
[0000] V. Preparation of Electrophoretic Displays from the Microcup Array
[0079] The preferred process of preparing the electrophoretic cells is illustrated schematically in FIGS. 6A-6D .
[0080] As shown in FIG. 6A , the microcup array ( 60 ) may be prepared by any of the alternative methods described in Section III above. The unfilled microcup array made by the methods described herein typically comprises a substrate web ( 63 ) upon which a base electrode ( 62 ) is deposited. The microcup walls ( 61 ) extend upward from the substrate ( 63 ) to form the open microcups.
[0081] As shown in FIG. 6B , the microcups are filled with a suspension of the charged pigment particles ( 65 ) in a colored dielectric solvent composition ( 64 ). In the example shown, the composition is the same in each microcup, i.e., in a monochrome display. In carrying out the sealing process of the present invention, the microcups are preferably partially filled (to prevent overflow), which can be achieved by diluting the display fluid with a volatile solvent (such as acetone, methyl ethyl ketone, isopropanol, hexane, and perfluorinated solvent FC-33 from 3M Co.,) and allowing the volatile solvent to evaporate. When a high boiling point perfluorinated solvent such as HT-200 (from Ausimont Co., Thorofare, N.J.) is used as the continuous phase of the display fluid, a perfluorinated volatile solvent such as FC-33 is particularly useful to control the level of partial filling.
[0082] As shown in FIG. 6C , after filling, the microcups are sealed with the sealing composition of the present invention to form a sealing layer ( 66 ). The sealing composition is typically overcoated onto the microcups partially filled with a display fluid and dried (i.e., hardened) on the display fluid. The sealed microcups optionally may be post treated by UV radiation or thermal baking to further improve the barrier properties.
[0083] As shown in FIG. 6D , the sealed array of microcup cells ( 60 ) is laminated with a second conductor film ( 67 ), preferably by pre-coating the conductor ( 67 ) with an adhesive layer ( 68 ) which may be a pressure sensitive adhesive, a hot melt adhesive, or a heat, moisture, or radiation curable adhesive. The laminate adhesive may be post-cured by radiation such as UV through the top conductor film if the latter is transparent to the radiation.
[0000] VI. Preparation of the Pigment/Solvent Suspension or Dispersion Composition
[0084] As described herein with respect to the various embodiments of the EPD of the invention, the microcups are preferably filled with charged pigment particles dispersed in a dielectric solvent (e.g., solvent ( 64 ) and pigment particles ( 65 ) in FIG. 6B .). The dispersion may be prepared according to methods well known in the art, such as U.S. Pat. Nos. 6,017,584, 5,914,806, 5,573,711, 5,403,518, 5,380,362, 4,680,103, 4,285,801, 4,093,534, 4,071,430, and 3,668,106. See also IEEE Trans. Electron Devices , ED-24, 827 (1977), and J. Appl. Phys. 49(9), 4820 (1978).
[0085] The charged pigment particles visually contrast with the medium in which the particles are suspended. The medium is a dielectric solvent which preferably has a low viscosity and a dielectric constant in the range of about 2 to about 30, preferably about 2 to about 15 for high particle mobility. Examples of suitable dielectric solvents include hydrocarbons such as decahydronaphthalene (DECALIN), 5-ethylidene-2-norbornene, fatty oils, paraffin oil, aromatic hydrocarbons such as toluene, xylene, phenylxylylethane, dodecylbenzene and alkylnaphthalenes, halogenated solvents such as, dichlorobenzotrifluoride, 3,4,5-trichlorobenzotrifluoride, chloropentafluoro-benzene, dichlorononane, pentachlorobenzene, and perfluorinated solvents such as perfluorodecalin, perfluorotoluene, perfluoroxylene, FC-43, FC-70 and FC-5060 from 3M Company, St. Paul Minn., low molecular weight halogen containing polymers such as poly(perfluoropropylene oxide) from TCI America, Portland, Oreg., poly(chlorotrifluoroethylene) such as Halocarbon Oils from Halocarbon Product Corp., River Edge, N.J., perfluoropolyalkylether such as Galden, HT-200, and Fluorolink from Ausimont (Thorofare, N.J.) or Krytox Oils and Greases K-Fluid Series from DuPont, Delaware. In one preferred embodiment, poly(chlorotrifluoroethylene) is used as the dielectric solvent. In another preferred embodiment, poly(perfluoropropylene oxide) is used as the dielectric solvent.
[0086] A non-migrating fluid colorant may be formed from dyes or pigments. Nonionic azo and anthraquinone dyes are particularly useful. Examples of useful dyes include, but are not limited to: Oil Red EGN, Sudan Red, Sudan Blue, Oil Blue, Macrolex Blue, Solvent Blue 35, Pylam Spirit Black and Fast Spirit Black from Pylam Products Co., Arizona, Sudan Black B from Aldrich, Thermoplastic Black X-70 from BASF, and anthraquinone blue, anthraquinone yellow 114, anthraquinone red 111, 135, anthraquinone green 28 from Aldrich. Fluorinated dyes are particularly useful when perfluorinated solvents are used. In the case of a pigment, the non-migrating pigment particles for generating the color of the medium may also be dispersed in the dielectric medium. These color particles are preferably uncharged. If the non-migrating pigment particles for generating color in the medium are charged, they preferably carry a charge which is opposite from that of the charged, migrating pigment particles. If both types of pigment particles carry the same charge, then they should have different charge density or different electrophoretic mobility. In any case, the dye or pigment for generating the non-migrating fluid colorant of the medium must be chemically stable and compatible with other components in the suspension.
[0087] The charged, migrating pigment particles may be organic or inorganic pigments, such as TiO 2 , phthalocyanine blue, phthalocyanine green, diarylide yellow, diarylide AAOT yellow, and quinacridone, azo, rhodamine, perylene pigment series from Sun Chemical, Hansa yellow G particles from Kanto Chemical, and Carbon Lampblack from Fisher. Submicron particle size is preferred. These particles should have acceptable optical characteristics, should not be swollen or softened by the dielectric solvent, and should be chemically stable. The resulting suspension must also be stable against sedimentation, creaming or flocculation under normal operating conditions.
[0088] The migrating pigment particles may exhibit a native charge, or may be charged explicitly using a charge control agent, or may acquire a charge when suspended in the dielectric solvent. Suitable charge control agents are well known in the art; they may be polymeric or non-polymeric in nature, and may also be ionic or non-ionic, including ionic surfactants such as Aerosol OT, sodium dodecylbenzenesulfonate, metal soaps, polybutene succinimide, maleic anhydride copolymers, vinylpyridine copolymers, vinylpyrrolidone copolymer (such as Ganex from International Specialty Products), (meth)acrylic acid copolymers, N,N-dimethylaminoethyl (meth)acrylate copolymers. Fluorosurfactants are particularly useful as charge controlling agents in perfluorocarbon solvents. These include FC fluorosurfactants such as FC-170C, FC-171, FC-176, FC430, FC431 and FC-740 from 3M Company and Zonyl fluorosurfactants such as Zonyl FSA, FSE, FSN, FSN-100, FSO, FSO-100, FSD and UR from Dupont.
[0089] Suitable charged pigment dispersions may be manufactured by any of the well-known methods including grinding, milling, attriting, microfluidizing, and ultrasonic techniques. For example, pigment particles in the form of a fine powder are added to the suspending solvent and the resulting mixture is ball milled or attrited for several hours to break up the highly agglomerated dry pigment powder into primary particles. Although less preferred, a dye or pigment for producing the non-migrating fluid colorant may be added to the suspension during the ball milling process.
[0090] Sedimentation or creaming of the pigment particles may be eliminated by microencapsulating the particles with suitable polymers to match the specific gravity to that of the dielectric solvent. Microencapsulation of the pigment particles may be accomplished chemically or physically. Typical microencapsulation processes include interfacial polymerization, in-situ polymerization, phase separation, coacervation, electrostatic coating, spray drying, fluidized bed coating and solvent evaporation.
[0091] For a black/white EPD, the suspension comprises charged white particles of titanium oxide (TiO 2 ) dispersed in a black dielectric solution containing a black dye or dispersed uncharged black particles. A black dye or dye mixture such as Pylam Spirit Black and Fast Spirit Black from Pylam Products Co. Arizona, Sudan Black B from Aldrich, Thermoplastic Black X-70 from BASF, or an insoluble black pigment such as carbon black may be used to generate the black color of the solvent. For other colored suspensions, there are many possibilities. For a subtractive color system, the charged TiO 2 particles may be suspended in a dielectric fluid of cyan, yellow or magenta color. The cyan, yellow or magenta color may be generated via the use of a dye or a pigment. For an additive color system, the charged TiO 2 particles may be suspended in a dielectric fluid of red, green or blue color generated also via the use of a dye or a pigment. The red, green, blue color system is preferred for most applications.
EXAMPLES
Example 1
Microcup Formulation
[0092] 35 Parts by weight of Ebecryl 600 (UCB), 40 parts of SR-399 (Sartomer), 10 parts of Ebecryl 4827 (UCB), 7 parts of Ebecryl 1360 (UCB), 8 parts of HDDA, (UCB), 0.05 parts of Irgacure 369 (Ciba Specialty Chemicals) and 0.01 parts of isopropyl thioxanthone (ITX from Aldrich) were mixed homogeneously and used for microembossing.
Example 2
Preparation of Microcup Array
[0093] A primer solution comprising of 5 parts of Ebecryl 830, 2.6 parts of SR-399 (from Sartomer), 1.8 parts of Ebecry 1701, 1 part of PMMA (Mw=350,000 from Aldrich), 0.5 parts of Irgacure 500, and 40 parts of methyl ethyl ketone (MEK) was coated onto a 2 mil 60 ohm/sq. ITO/PET film (from Sheldahl Inc., MN.) using a #3 Myrad bar, dried, and UV cured by using the Zeta 7410 (5 w/cm 2 , from Loctite) exposure unit for 15 minutes in air. The microcup formulation prepared in Example 1 was coated onto the treated ITO/PET film with a targeted thickness of about 50 μm, embossed with a Ni—Co male mold having a 60 (length)×60 (width) μm repetitive protrusion square pattern with 25-50 μm protrusion height and 10 μm wide partition lines, UV cured from the PET side for 20 seconds, removed from the mold with a 2″ peeling bar at a speed of about 4-5 ft/min. Well-defined microcups with depth ranging from 25 to 50 μm were prepared by using male molds having corresponding protrusion heights. Microcup arrays of various dimension such as 70 (length)×70 (width)×35 (depth)×10 (partition), 100 (L)×100(W)×35(D)×10(P), and 100(L)×100(W)×30(D)×10(P) μm were also prepared by the same procedure.
Example 3
Pigment Dispersion
[0094] 6.42 Grams of Ti Pure R706 were dispersed with a homogenizer into a solution containing 1.94 grams of Fluorolink D from Ausimont, 0.22 grams of Fluorolink 7004 also from Ausimont, 0.37 grams of a fluorinated copper phthalocyanine dye from 3M and 52.54 grams of a perfluorinated solvent HT-200 (Ausimont).
Example 4
Pigment Dispersion
[0095] The same as Example 3, except the Ti Pure R706 and Fluorolink were replaced by a polymer coated TiO 2 particles PC-9003 from Elimentis (Highstown, N.J.) and Krytox (Du Pont) respectively.
Example 5
Microcup Sealing
[0096] The electrophoretic fluid prepared in Example 3 was diluted with a volatile perfluorinated co-solvent FC-33 from 3M and coated onto a 35 microns deep microcup array prepared in Example 2. The volatile cosolvent was allowed to evaporate to expose a partially filled microcup array. A 7.5% solution of polyisoprene (97% cis, from Aldrich) in heptane was then overcoated onto the partially filled microcups by a Universal Blade Applicator with an opening of 3 mil. The overcoated microcups were then dried at room temperature. A seamless sealing layer of about 7-8 μm thickness (dry) with acceptable adhesion and uniformity was formed on the microcup array. No observable entrapped air bubble in the sealed microcups was found under microscope. A second ITO/PET conductor precoated with an adhesive layer was laminated onto the sealed microcups. The electrophoretic cell showed satisfactory switching performance with good flexure resistance. No observable weight loss was found after being aged in a 66° C. oven for 5 days.
Example 6
Microcup Sealing
[0097] The same as Example 5, except the thickness of the polyisoprene layer was reduced to 4 microns by using a blade applicator of 2 mil opening. Pinholes and broken sealing layer were clearly observed under optical microscope.
Example 7-14
Microcup Sealing
[0098] The same as Example 5, except the sealing layer was replaced by polystyrene, polyvinylbutyral (Butvar 72, from Solutia Inc., St. Louis, Mo.), and thermoplastic elastomers such as SIS (Kraton D1107, 15% styrene), SBS (Kraton D1101, 31% styrene) SEBS (Kraton G1650 and FG1901, 30% styrene), or EPDM (Vistalon 6505, 57% ethylene). The results are summarized in Table 1. As it can be seen from Table 1, thermoplastic elastomers enabled thinner and higher quality sealing even on microcups of wide openings.
TABLE 1 Sealing of microcups Estimated dry Cup dimension Coating quality Coating quality Example No. Sealing Polymer Coating solution thickness (L × W × D × P), um (visual) (Microscopic) comparative 6 Polyisoprene 7.5% in heptane 4-5 um 60 × 60 × 35 × 10 fair pinholes, (97% cis) broken layer comparative 5 Polyisoprene 7.5% in heptane 7-8 um 60 × 60 × 35 × 10 good good (97% cis) comparative 7 Polystyrene 30% in toluene 7-8 um 60 × 60 × 35 × 10 very poor, incomplete severe dewetting sealing, defects comparative 8 Butvar 72 8.5% in 4-5 um 60 × 60 × 35 × 10 poor fair isopropanol reproducibility 9 SIS (Kratone 4% in Heptane 4-5 um 70 × 70 × 35 × 10 good good D1107); 15% Styrene 10 SIS (Kratone 4% in Heptane 3-4 um 100 × 100 × 30 × 10 good good D1107); 15% Styrene 11 SBS (Kraton 10% in toluene/ 4-5 um 70 × 70 × 35 × 10 good good D1101), 31% heptane (20/80) styrene 12 SEBS(Kraton FG- 10% in xylene/ 4-5 um 70 × 70 × 35 × 10 good good 1901, 30% Isopar E (5/95) styrene, 1.5% maleic anhrdride) 13 SEBS(Kraton 5% in toluene/ 4-5 um 70 × 70 × 35 × 10 good good G1650, 30% heptane (5/95) styrene) 14 EPDM (Vistalon 10% in Isopar E 4-5 um 70 × 70 × 35 × 10 good 6505, 57% ethylene)
[0099] While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, materials, compositions, processes, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto.
[0100] For example, it should be noted that the method of the invention for making microcups may also be used for manufacturing microcup arrays for liquid crystal displays. Similarly, the microcup selective filling, sealing and ITO laminating methods of the invention may also be employed in the manufacture of liquid crystal displays.
[0101] It is therefore wished that this invention to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of the specification if need be.
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The invention relates to a novel sealing composition for the manufacture of an electrophoretic or liquid crystal display, and a sealing process using the composition. The composition allows electrophoretic or liquid crystal cells to be seamlessly sealed and the sealing layer free of any defects.
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CROSS-REFERENCES TO RELATED APPLICATIONS
None
BACKGROUND
This invention relates to an apparatus for detecting the relevant properties of subterranean formations while drilling wells for oil, natural gas, and geothermal energy. More specifically, the invention relates to the measurement of the linear rebound position, velocity, and acceleration of a down-hole fluid-driven percussive piston which impacts a drill bit, thus penetrating the subterranean formations. Such pistons are referred to in the industry as “down-hole hammers,” examples of which are disclosed in U.S. Pat. Nos. 5,396,965, 5,488,998, and 5,497,839. U.S. Pat. No. 5,396,965 discusses in detail the principles involved in the operation of a down-hole hammer actuated by drilling mud. These patents are incorporated herein. Drilling mud is only one of a number of different fluids used to drive down-hole hammers; any gas or liquid such as air, water, brine, or a foam combination could drive the mechanism upon which this invention is based.
The materials to be penetrated by such a drill vary by the type, depth, and location of the well. Knowledge of the lithology being drilled assists the drilling crew in the selection of drilling parameters and indicates when a “pay zone” is near. Thus, it would be very useful to obtain information about the physical characteristics of the formations being drilled. Specifically, it is helpful to know the hardness of the formations, their approximate composition, and whether or not they are part of a subterranean fracture. This would allow the surface team to steer the bit towards places where the type of energy being sought can be efficiently acquired. In the drilling process, it is also advantageous to optimize the drilling rate to minimize labor and tool replacement costs. The optimum set of conditions such as frequency of hammer impact, force of impact, presence of pulsed jet action, and rotational speed of the drill bit, varies by the hardness, depth, and composition of the formations being drilled. For example, impact-resistant diamond cutters that have a long life in medium hardness rock will tend to decompose and wear away under the high temperatures generated by drilling through hard, abrasive formations. If real-time data on the characteristics of the subterranean formations being penetrated could be acquired, a control system could be implemented to adapt the drilling conditions to the type of rock encountered.
When two objects collide, the energy with which they rebound depends upon the elasticity and hardness of both. Thus, an analysis of the rebound characteristics (position, velocity, and acceleration over time) of the hammer will also reveal the hardness and general makeup of the formations in contact with the bit. The harsh environment in which the hammer operates makes conventional measurement methods impractical; potentiometers, interferometers, and other instruments that measure displacement will not function well in the presence of high-pressure abrasive fluids, vibrations, and impact forces. There is a need for some novel method of discovering the hammer's position, velocity, and acceleration during the short period of time after it strikes the drill bit.
Additional utility would attend such a method if it could measure the position, velocity, or acceleration of the hammer at other points in its reciprocating motion as well. For example, simple knowledge of the impact velocity or frequency of the hammer may be used to help detect wear or malfunction of the hammer. As a second example, knowledge of the position of the hammer may enable the use of more flexible electromechanical valves to control hammer motion. In typical hammer mechanisms, such as those described in the patents above, the only variables that can be altered during drilling are the pressure or flow rate of fluid entering the drill string. This allows the drilling team to control only the frequency and force of impact, both of which must simultaneously increase or decrease. Optimization of the drilling process requires more control over the motion of the hammer, some of which can be attained through the use of computer-controlled valves. These would allow the drilling crew to dynamically modify the stroke of the hammer, thus, for example, increasing the hammer frequency while decreasing the force of imp act, etc. This type of control system would need data describing the hammer's displacement over its full range of motion.
Several different types of transducers exist; they are based upon principles such as variable resistance, optical interference, acoustic rebound, piezoelectric excitation, and magnetic flux variance. The following are examples of some that could be configured to measure the motion of the piston.
One means of optical measurement is the interferometer. It functions by focusing a beam of coherent light through a beam splitter. One part of the beam bounces off of a stationary mirror while the other bounces off of a moveable mirror; when the two returning beams are simultaneously visible, differences in the observed wavelengths indicate the displacement of the moveable mirror. In hammer machines that run on transparent fluids such as air, this can be used to determine the location of the piston over time.
Acoustic rebound transducers utilize sonic or ultrasonic waves and measure the speed of a passing object by utilizing such phenomena as the “Doppler effect.”
Variable resistance transducers include potentiometers, which measure the displacement of an electrical contact along a coil of wire. The wire of the coils is of a known resistivity; when the contact closes the circuit with a known voltage source by touching one of the coils, the resulting output voltage is proportional to the length of wire the current must travel through. Thus, the voltage is a measure of the relative displacement of the contact and the coil.
Piezoelectric transducers function based on the unique tendency of some materials, such as single crystal quartz, to develop a charge when subjected to a mechanical strain. The charge generated is proportional to the force on the crystal; thus, the piezoelectric load cell can be used to measure force. This, in turn, yields a measurement of the acceleration when the load cell is attached to a moving object such as the piston; the weight of the cell will press on the crystal to produce a measurable charge in proportion to the magnitude of the acceleration. Since they measure changes in force, piezoelectric crystals can also readily be configured to measure pressure changes in fluids. Such a pressure transducer mounted in the fluid cavity above the piston or likewise on the drill string closer to the point of impact would yield data that generally describes the motion of the hammer, as derived from the cyclical fluid pressure variations.
There are also other types of transducers that operate based on measurement of changes in magnetic flux. Linear variable displacement transducers, or LVDT's, have one coil wrapped around a magnetically permeable core. When the core moves between two other concentric coils, the ac voltage through the first coil will excite a voltage output in the other two in proportion to the core's proximity to them. Thus, the LVDT measures the location, or displacement, of the core.
When the piston strikes the impact mass, there are two components to its motion: the transient response and the steady response. The transient response is the portion of the waveform induced as a direct result of the impact; its amplitude upon impact is significant but drops to zero before the end of the cycle. The steady response is the normal, near-sinusoidal waveform of the piston's motion resulting from the fluid pressures that actuate it. The transient response yields information regarding the impact and consequently the physical makeup of the formations being impacted. The steady response describes the piston's general motion and therefore provides data that can be used to deduce the piston's frequency, stroke length, and impact force.
For the analysis of subterranean features as well as diagnostic testing of the hammer's operation, the displacement, velocity, and acceleration of the piston are all useful quantities. If one is known, the other two can be determined from it by integration or differentiation. However, since the piston does not always strike the impact mass or reach the same point at the top of its stroke, there may be a need for a position datum if displacement is not the variable being directly measured. In other words, it might be necessary to know at which point in time the piston reaches a certain position once each cycle because inaccuracies in the integration over time may build up and yield an inexact measurement of the position of the piston. The sensor could be a simplified version of any of the displacement transducers discussed above, as it only needs to provide a simple signal to indicate that the piston has reached the predetermined position.
For the invention, the magnetic flux-based transducer was chosen as the most viable for down-hole applications. Lateral vibrations in the piston's movement, abrasive down-hole conditions, and high velocities make it difficult to use any transducer in which the moving and stationary parts must be in contact with each other, such as the potentiometer. It is similarly impractical to extend any wires from the piston to a stationary part of the drill string because the piston's motion will tend to break the wires in fatigue while the abrasive effects of the drilling fluid will rapidly wear away exposed electrical conductors. For these reasons, it is desirable to use a transducer in which the only communication between moving and stationary parts does not require contact between the piston and the drill string. A magnetic coupling accomplishes this criterion and provides a particular advantage for down-hole applications, since such a coupling may operate in typically opaque drilling mud. Although either permanent or electrically activated magnets can be used, permanent magnets are preferable for mounting in a hammer piston because they reduce the number of electrical contacts required.
Yet further functionality of the above-mentioned measurement method is apparent when one considers that an electrical signal generated by this method may be useable as an electrical power source. Data acquisition, data transmission, and control systems, as described above, require a steady source of power down-hole. Due to the time and expense required to retrieve the drill from the borehole, it is critical to find a power system that will operate for as long as possible without the need for maintenance or replacement. A down-hole power system should be designed to operate for at least 100 hours.
Several methods of providing electricity down-hole have been tested with limited success. New lithium technology currently being implemented in batteries cannot provide a long enough life to be useful for powering complex systems down-hole. The abrasive environment makes turbines and other bladed rotary generators particularly short lived. The motion of the down-hole hammer, however, may be used to provide the needed means of down-hole electricity generation.
The present invention is a method of measuring the motion characteristics of the hammer through the use of a transducer mounted on the piston, drill bit, or drill string. A transducer is a device that converts one form of energy to another. Thus, in this invention, a portion of the energy resident in the hammer is converted into electrical energy. The present invention thus becomes not only a motion sensor, but also an electrical generator.
The preferred embodiment of the transducer consists of a series of coils and magnetic flanges mounted inside the hammer. In this embodiment, the transducer will provide valuable information on the transient and steady motion of the hammer in the form of an electric signal strong enough to constitute a power source.
SUMMARY
The present invention constitutes a method for satisfying three functional needs in implementing down-hole control, measurement, and telemetry systems. This device provides a means of measuring the hammer's impact characteristics, a means of determining its general displacement profile over time, and a means of generating electrical power for use in down-hole systems.
Combining existing technologies solves these problems. First of all, fluid-driven hammers, as shown in U.S. Pat. Nos. 5,396,965, 5,488,998, and 5,497,839 are used to convert hydraulic pressure to linear kinetic energy. Linear alternators, such as those described in U.S. Pat. Nos. 4,454,426, 4,602,174, 5,180,939, and 5,389,844 convert linear kinetic energy to electrical energy. These patents are incorporated herein. The amplitude of the electric waveform produced is in proportion to the velocity of the linear reciprocator.
The basic principles are as follows. When a magnetic field passing through a coil changes in strength or orientation, a voltage is induced in proportion to the change in the field divided by the time required for the change to occur. This principle is commonly used to convert between mechanical and electrical forms of energy. The relative motions of the magnets and the coils can be rotational or linear. Linear reciprocating elements have been used as components for linear motors and alternators, such as those disclosed in U.S. Pat. Nos. 4,454,426 and 4,602,174, as well as measurement devices such as linear variable displacement transducers (LVDT's). A coil and magnet system is used to measure the location of a compressor piston with respect to the cylinder head in U.S. Pat. No. 5,342,176, incorporated herein by this reference.
The preferred embodiment of this invention utilizes permanent magnets mounted on a stationary member in the hammer housing. Coils are also mounted on a stationary member and the motion of the hammer (a mass of magnetic material) past the permanent magnets causes a changing flux field. This changing flux field induces a current in the coils, which can be measured and used to feed electrical devices. In a second embodiment of this invention, the magnets may be mounted on the hammer, which reciprocate with respect to coils mounted on a stationary member in the hammer housing. Similarly, the measurement device can be mounted on the drill bit, which will display a similar rebound characteristic. The hammer's position and acceleration can also be obtained by integration and differentiation, respectively. This yields the desired information concerning the rebound and general motion of the hammer.
The voltage induced by such a configuration produces an alternating current waveform. If the magnetic field is strong and there are a large number of coils, the amplitude of the waveform will be large enough to constitute a signal useful as a power source. See U.S. Pat. No. 4,491,738, incorporated herein, for an example of a machine that generates small amounts of electricity down-hole independent of a hammer.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a sectioned view of the cylindrical hammer subassembly that shows the transducer (mounted in the hammer housing), signal-conveying wires, and signal analysis and rectification modules.
FIG. 2 is a sectioned view of the same hammer subassembly with the transducer mounted on the drill bit.
FIG. 3 is a sectioned view of the preferred embodiment of the transducer/generator mounted in the hammer housing.
FIG. 4 is a sectioned view of the portion of the hammer containing the transducer, in a region towards the bottom of the transducer (section A—A in FIG. 3 ); it shows the layout of the magnetic rings and flanges.
FIG. 5 is a sectioned view of a region towards the top of the hammer transducer (section B—B in FIG. 3 ).
FIG. 6 is the view shown in FIG. 3; the hammer is near the bottom of its stroke.
FIG. 7 is a blowup of the portion of FIG. 6 contained by the dotted lines. The arrows represent the path of the magnetic flux.
FIG. 8 is the sectioned view of FIG. 3 depicting the hammer near the top of its stroke.
FIG. 9 is a blowup of FIG. 8 . The arrows represent the path of the magnetic flux.
FIG. 10 is a graph that shows the motion of the hammer over time, as simulated by a testing apparatus that incorporates the preferred embodiment transducer.
FIG. 11 is a graph that shows the signal generated by the preferred embodiment transducer over time.
FIG. 12 is a graph of the scaled numerical integral of the testing data shown in FIG. 11, as obtained through the trapezoidal method.
DETAILED DESCRIPTION
FIG. 1 depicts the invention in generalized form. The hammer 21 is shaped like a large tube surrounding the throat 24 and, in turn, surrounded by the wall of the drill string 25 . The hammer is actuated by one or more valves (not shown—see U.S. Pat. No. 5,396,965 for details on the operation of one particular hammer design). The hammer 21 reciprocates in axial fashion and at the bottom of its stroke, strikes the top of the drill bit 23 . The drill bit 23 is designed to transmit the impact of hammer 21 to the rock below.
The transducer 22 is one of several types that measure position, velocity, or acceleration. It can be one of the optical, acoustic, variable resistance, piezoelectric, or, most preferably, magnetic flux-based type. The transducer 22 is preferably mounted to the throat 24 and generates an electric current as the hammer 21 moves. The electric current travels through the wires 26 to reach the signal processor 27 . The signal processor 27 reads the electric current from the hammer transducer 22 and interprets it to provide an output signal which describes the position, velocity, or acceleration of the piston 21 ; this signal can be analyzed by the surface crew or a down-hole computer. Other transducers similar to that of FIG. 1 may be placed on the throat 24 or the drill string 25 to provide additional information regarding the position, velocity, or acceleration of the piston 21 .
The substantially sinusoidal signal generated by the transducer 22 continues on to the power supply circuitry 28 which adjusts its waveform to a direct current form (or conditioned alternating current) of the proper voltage required by down-hole devices. The output from the power supply circuitry may be used as the power source for electric down-hole components.
FIG. 2 shows a similar system with the transducer 22 located inside the drill bit 23 . When the hammer 21 strikes the bit, the rebound characteristics of the bit will be similar to that of the hammer 21 . The current once again passes through the wire 26 to reach the signal processor 27 . A power supply may be added in this case as well, although the power output of this particular design will be much lower than that shown in FIG. 1, due to the small relative motion of the hammer bit 23 .
FIG. 3 is a sectioned view of the preferred embodiment of the transducer 22 , attached to the throat 24 as in FIG. 1 . The inner wall of the hammer 21 has been bored out to accommodate the transducer 22 . Both hammer 21 and throat 24 are constructed from ferritic or otherwise magnetic materials, such as mild or high strength steels. A lower flange 31 , also constructed from magnetic material, is securely positioned on throat 24 by retainer rings 38 and 39 . Between the bore of the lower flange 31 and the throat 24 are located a plurality of permanent magnets 33 . The lower flange is constructed so as to reside, at least in part, in close proximity to the inner wall of hammer 21 . Just uphole of the lower flange 31 , is located a continuously wound coil of insulated electrical wire 34 , which is wrapped around the throat 24 . A non-magnetic retainer ring 37 rests against the top of the coil 34 and maintains the axial position of the coil 34 . A non-magnetic sleeve 35 encloses the coil 34 and separates it from the fluid space 36 . The upper flange 32 encircles the coil 34 in close proximity. The upper flange is constructed of magnetic material, and is fixedly attached to the inner wall of the hammer 21 .
The magnets 33 are of radial polarity: each magnet has its north pole on the outer face and its south pole on the inner face. The magnets 33 are constructed of a magnetic material such as Alnico, neodymium, samarium cobalt, or a magnetic ceramic. The retainer rings 37 , 38 , and 39 are constructed of some material with low magnetic permeability, such as 300 series stainless steel.
The signal-conveying wire 26 is an extension of the wire coils 34 and is wrapped around the throat 24 in a spiral configuration so that it carries the current to the signal processor 27 (shown in FIG. 1 ).
The wire coils 34 , composed a material of low electrical resistivity, are insulated from each other and enclosed by a nonmagnetic sleeve 35 which protects them from the abrasives in the drilling fluid. The sleeve 35 can be composed of an austenitic (a nonmagnetic molecular phase) stainless steel, chrome, ceramic or some similar hard substance which is nonmagnetic, abrasion-resistant, and applicable at low temperatures. Similarly, the sleeve 35 might also consist of a soft polymer or elastomer that will resist wear by abrasive elements in the drilling fluid.
The fluid space 36 extends through the bore of hammer 21 and provides fluid communication between a cavity above the hammer 21 and a cavity below it. The magnetic flanges 31 and 32 , the sleeve 35 , and the retainer rings 37 , 38 , and 39 are dimensioned such that they allow mud to flow past them without significant pressure drop.
FIG. 4 is a cross section of the preferred embodiment of the transducer 22 , as seen from along the axis of the drill string. This figure shows the radial orientation of the throat 24 , the magnets 33 , the lower flange 31 , and the piston 21 . As shown, fingers 40 protrude outward from the body of the lower flange 31 , so as to obtain dose proximity with piston 21 , while still providing space for mud to flow past the flange (see fluid space 36 ). The flange 31 is constructed of steel, iron, or some similar material with a high magnetic permeability.
FIG. 5 is a second cross section of the preferred embodiment of the transducer 22 as seen from along the axis of the drill string. This figure shows the radial orientation of the throat 24 , coils 34 , sleeve 35 , upper flange 32 , and piston 21 . As shown, fingers 41 protrude inward from the body of the upper flange 32 , so as to obtain close proximity with coils 34 , while still providing space for conducting flow past the flange (see fluid space 36 ). The flange 32 is constructed of steel, iron, or some similar material with a high magnetic permeability.
FIG. 6 is the same cross-sectional view as that shown in FIG. 3, except the hammer 21 is shown near the bottom of its stroke. FIG. 7 is a magnified view of part of the transducer 22 in FIG. 6. A high-permeability path through the coils 34 exists, due to the close proximity of flanges 31 and 32 with the hammer 21 and coil 34 respectively. This path is shown by the bold arrows in the figure. The magnetic flux will travel through this path to complete the circuit between the north and south poles.
FIG. 8 is similar to FIG. 6, except that it shows the hammer 21 near the top of its stroke; FIG. 9 depicts the resulting flux paths. The flux will now travel through a longer path around the coils because the upper flange 32 has moved to the top of the coils, thereby increasing the length of the high-permeability flux path.
Operation of the transducer 22 proceeds as follows. As the hammer 21 oscillates, the magnetic flux path will vary from that shown in FIG. 7 to that shown in FIG. 9 . As per Faraday's law of induction, any change in magnetic flux through the coils 34 will generate a voltage, and therefore, induce an electric current in the coils 34 . This electric signal is proportional to the rate of change of the magnetic flux, which is proportional to the velocity with which the hammer 21 moves. Thus, this signal is a measure of the speed and direction of the motion of the hammer 21 . The principles involved in generating electricity by manipulating magnetic flux are described in detail in U.S. Pat. Nos. 4,454,426 and 5,342,176. Although the drawings depict a single coil and a single array of magnets, several coil/magnet couples may be used to increase the magnitude or quality of the output signal.
FIG. 10 shows the position of the hammer 21 , as measured by a position sensor mounted on a testing apparatus designed to simulate its motion. FIG. 11 is a sample of testing data that shows the voltage induced by the motion in FIG. 10 . This voltage is proportional to the velocity of the hammer, which can be obtained by taking the time derivative of the hammer position shown in FIG. 10 .
In practice, the transducer will yield a signal lie that of FIG. 11 which must be integrated and scaled to give the position of the hammer. The signal processor 27 can perform this function in a number of different ways including numerical integration and curve-fitting in conjunction with mathematical integration.
There are several well-known algorithms the signal processor 27 can use to numerically integrate the voltage signal of FIG. 11 . Two of these are the trapezoidal method and Simpson's rule. The integral of a function is simply the area between the function and the axis that represents zero. The trapezoidal method and Simpson's rule both separate the function into a series of narrow strips; the end of the strip can be approximated as a straight line, as in the trapezoidal method, or a polynomial curve, as in Simpson's Rule. The areas of the strips can be easily computed and added to form a fairly accurate estimate of the area between the function and the zero axis. The signal processor 27 would form a new strip after it takes each voltage measurement; by adding the area of this strip to the sum of the areas previously calculated, the signal processor 27 would keep a running integral of the voltage. FIG. 12 is the scaled numerical integral of the testing data shown in FIG. 11, as obtained through the trapezoidal method. With some small deviations, its shape is very similar to that of the output of the position sensor, which is shown in FIG. 10 .
There are also several well-known methods that could be used to approximate the voltage output of the transducer as a function that can be mathematically integrated. The voltage output can be fit to sinusoidal, polynomial, or exponential waveforms; combinations of mathematical functions can also be used. As a further alternative to the digital numerical methods described above, an analog integrator and amplifier may be constructed to give position information.
Power supplies are readily available to convert one electric signal to another as required by the load, or the device that requires power. Since most down-hole devices require DC power, the power supply of FIG. 1 would convert the signal from the AC output of the transducer to a DC waveform. The power supply could also incorporate a battery, capacitor, or both to store up voltage for times when the power required exceeds the transducer output.
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A method of creating an electric signal that describes the motion of a down-hole, fluid-driven percussive tool is disclosed. The signal is obtained by attaching an electromagnetic transducer to the percussive tool, the member impacted by it, or the drill string. The rebound characteristics of the tool yield a measurement of the physical characteristics of the subterranean formation being penetrated. The tool's position over time is useful for diagnosing and regulating the operation of the tool. The transducer can also be configured to generate a signal large enough to be used as a power source.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/701,849, which is a national stage application under 35 U.S.C. §371 from PCT Application No. PCT/US11/039949, filed Jun. 10, 2011, which claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/353,857, filed Jun. 11, 2010, the contents of which are hereby incorporated by reference.
GOVERNMENT SUPPORT
[0002] This invention was made with government support under Grant Nos. R01 GM054403, U01 AI075466, and R01 AI090745, awarded by the National Institutes of Health. The government has certain rights in this invention.
BACKGROUND OF THE INVENTION
[0003] Certain monoclonal antibodies have therapeutic potential against a particular disease, even though similar antibodies seldom or never arise during disease progression in most humans. For example, in models of HIV infection antibody 2G12 is known to neutralize a broad range of HIV strains and protect rhesus macaques, but 2G12-like antibodies are rarely produced in HIV-positive humans. In such cases, a “reverse immunology” approach would be desirable, in which an immunogen is designed which structurally mimics the epitope of the therapeutically useful monoclonal antibody. Immunization with this epitope mimic would then elicit an antibody response mimicking the monoclonal antibody.
[0004] The success of this strategy depends on the extent to which one can design a molecule that is a good structural and conformational mimic of the native epitope. This goal requires a good structural or conformational understanding of the epitope structure. “Carbohydrate epitopes” are epitopes in which a carbohydrate is a necessary component for antibody binding. However, the antibody-epitope binding interaction is rarely understood at the atomic structural level and, in most cases, it is not known whether the antibody binds to structural features neighboring the carbohydrate in addition to the carbohydrate itself. Moreover, carbohydrates are flexible and may exhibit different conformational profiles when attached to structures other than those present in the actual target protein.
[0005] For example, the majority of HIV vaccine approaches to date have tested either HIV protein subunits or peptides, and/or caused the host to make these proteins by intracellular delivery of HIV DNA using viral vectors or gold particles. Because a broadly-neutralizing antibody, 2G12, binds to a cluster of carbohydrates on the viral envelope protein gp120, a few groups have designed and tested synthetically clustered carbohydrate immunogens in an attempt to mimic the 2G12 epitope and thus elicit 2G12-like antibodies. In these approaches, the backbones linking the carbohydrates were flexible organic chains or cyclic peptides that were easy to synthesize. No study has described an attempt to mimic in an exact way the natural backbone in which the carbohydrates are embedded. The choice of backbone is key; due to the flexibility of carbohydrates, their conformation, spacing, and orientation is undoubtedly influenced by the surfaces they are embedded within, and the flexible carbohydrate cluster immunogens designed to date have not achieved true conformational mimicry of the epitope. The choice of backbone is also important because the peptide structures of gp120 in which the carbohydrates are embedded are likely make some contact with 2G12 and comprise part of the epitope.
[0006] Further, other important information regarding 2G12 binding to HIV remains unknown, including: precisely which oligomannans on the gp120 surface are bound by the antibody; whether the antibody also binds to polypeptide surface residues; and how the oligomannans are conformationally supported by the protein. Synthetic clusters of oligomannans mounted on non-natural designed scaffolds have so far failed to elicit 2G12-like antibodies, possibly because such epitope mimics do not adequately resemble the native epitope. Even with perfect structural knowledge of an epitope, a priori design of antigens that faithfully mimic its structure is currently impossible.
[0007] Additionally, a major limitation of RNA and DNA aptamers is that the nucleotide building blocks are limited to the naturally occurring bases and close analogues that act as substrates for DNA or RNA polymerases. The utility of the oligonucleotide framework, and the power of the selection process, could be greatly extended if the bases could be more extensively modified.
SUMMARY OF THE INVENTION
[0008] In certain embodiments, the invention relates to a method, comprising the steps of:
(a) combining a plurality of oligonucleotides, a first DNA polymerase, and a plurality of deoxyribonucleotide triphosphates, wherein
the oligonucleotides comprise a first primer binding site on the 5′ end, a randomized region, and a stem-loop region; the randomized region is located between the first primer binding site and the stem-loop region; the stem-loop region comprises a second primer binding site; and at least one of the deoxyribonucleotide triphosphates comprises a reactive substituent;
thereby forming a plurality of extended oligonucleotides comprising an original strand and an extended strand, wherein the extended strand comprises at least one reactive substituent; (b) combining a plurality of modifying compounds and the plurality of extended oligonucleotides under reaction conditions, thereby forming a plurality of modified extended oligonucleotides comprising the original strand and a modified extended strand; and (c) combining a plurality of primers complementary to the second primer binding site, a second DNA polymerase, the plurality of modified extended oligonucleotides, and a plurality of deoxyribonucleotide triphosphates thereby creating duplexes with the original strands and displacing the modified extended strands.
[0018] In certain embodiments, the invention relates to a method, comprising the steps of
(a) combining a plurality of oligonucleotides, a first DNA polymerase, and a plurality of deoxyribonucleotide triphosphates,
wherein the oligonucleotides comprise a first primer binding site on the 5′ end, a randomized region, and a stem-loop region; the randomized region is located between the first primer binding site and the stem-loop region; the stem-loop region comprises a second primer binding site; and at least one of the deoxyribonucleotide triphosphates comprises a reactive substituent;
thereby forming a plurality of extended oligonucleotides comprising an original strand and an extended strand, wherein the extended strand comprises at least one reactive substituent; (b) combining a plurality of modifying compounds and the plurality of extended oligonucleotides under reaction conditions, thereby forming a plurality of modified extended oligonucleotides comprising the original strand and a modified extended strand; (c) combining a plurality of primers complementary to the second primer binding site, a second DNA polymerase, the plurality of modified extended oligonucleotides, and a plurality of deoxyribonucleotide triphosphates thereby creating duplexes with the original strands, displacing the modified extended strands, and forming a plurality of modified single-stranded oligonucleotides; (d) combining the plurality of modified single-stranded oligonucleotides and a target protein; (e) isolating the modified single-stranded oligonucleotides that bind to the target protein, thereby identifying a plurality of selected oligonucleotides; (f) amplifying the plurality of selected oligonucleotides, thereby forming a plurality of complementary oligonucleotides; and (g) preparing a plurality of regenerated selected oligonucleotides from the plurality of complementary oligonucleotides.
[0034] In certain embodiments, the invention relates to an oligonucleotide, wherein the oligonucleotide comprises at least one non-natural deoxynucleoside; and the non-natural deoxynucleoside comprises an oligosaccharide moiety and a triazole moiety.
BRIEF DESCRIPTION OF THE FIGURES
[0035] FIG. 1 depicts an original oligonucleotide library with a primer binding site on the 5′ end, followed by a randomized region (˜25 bases) followed by a stem-loop region containing a second primer binding site. FIG. 1 discloses SEQ ID NOS 1-7, respectively, in order of appearance.
[0036] FIG. 2 depicts a schematic representation of an extended hairpin product containing ethynyl deoxyuridine (EDU) (an extended oligonucleotide comprising an original strand and an extended strand). Polymerase extension with 5-ethynyl-deoxyuridine triphosphate (EDUTP) instead of thymidine triphosphate allows for the incorporation of a moiety with a reactive substituent that can be modified using “click chemistry.”
[0037] FIG. 3 depicts a schematic representation of a “clicked” hairpin (a modified extended oligonucleotide comprising an original strand and a modified extended strand). The extended hairpin product is purified and subsequently modified by “click chemistry.” In this case, an azido sugar (a “modifying compound”) reacts with the pendant ethynyl group (a “reactive substituent”) to form a triazole in a copper-catalyzed reaction. This chemistry is robust and should be applicable to any azide.
[0038] FIG. 4 depicts the displacement of the modified extended strand by providing a primer complementary to the primer binding site, creating a duplex with the naturally occurring nucleotides.
[0039] FIG. 5 depicts regeneration of the hairpin. Modified oligonucleotides that bind to a target protein, in this case the monoclonal antibody 2G12, may be isolated and amplified via PCR using primers aptamerfor-biotin and aptamerrev. Purification of the non-biotinylated strand and an additional extension using the biotinylated regeneration primer, followed by purification of the non-biotinylated extended product regenerates the hairpin as shown. Iterative rounds of selection and amplification will enrich the pool of modified oligonucleotides that bind to the target. The PCR product can be cloned and sequenced to identify the modified oligonucleotides that bind to the target. This procedure was used to construct a library of mannose-modified oligonucleotides, and identify modified oligonucleotides that bind to MAb 2G12.
[0040] FIG. 6 depicts graphically the extent of binding to MAb 2G12 of three modified oligonucleotides. Man4-18, Man4-16 and Man4-18 bind with affinities of 270±40 nM, 220±50 nM and 330±30 nM, respectively, after 7 rounds of selection. In contrast, less than 3% of the initial random library bound to MAb2G12, and no significant binding was observed for the arbitrarily chosen sequence Gal3-6.
[0041] FIG. 7 depicts the structures of two oligosaccharides of the invention.
[0042] FIG. 8 depicts a route for the synthesis of oligomannan azide 5.
[0043] FIG. 9 is a schematic representation of a method of the invention.
[0044] FIG. 10 depicts four additional oligosaccharide-azide compounds (V, VI, VII, and VIII) of the invention. Also contemplated are oligosaccharide-azide compounds discussed in the following: Astronomo, R. D.; et al. Chem. Biol. 2010, 17, 357-370; Calarese, D. A.; et al. Proc. Natl. Acad. Sci. USA 2005, 102, 13372-13377; Lee, H. K.; et al. Angew. Chem. Int. Ed. Engl. 2004, 43, 1000-1003; these articles are hereby incorporated by reference in their entireties.
[0045] FIG. 11 depicts additional oligosaccharide-azide compounds (IX, X, XI, and XII) of the invention. In formula XII, “A” represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties. See Wang, J.; et al. Org. Biomol. Chem. 2007, 5, 1529-1540; Wang, S.-K., et al. Proc. Natl. Acad. Sci. USA 2008, 105(10), 3690-3695; these articles are hereby incorporated by reference in their entireties.
[0046] FIG. 12 depicts the sequences of clones, (+)-strand, from 5′ end to 3′end (left to right) (italicized=loop region; bold=stem region; [bracketed]=aptamerrev binding region). FIG. 12 discloses SEQ ID NOS 8-22, respectively, in order of appearance.
[0047] FIG. 13 depicts directed evolution approach to improved 2G12 antigen design. (a) A schematic representation of the interaction of 2G12 and gp120. Domain-exchanged antibody 2G12 binds at least two of the many high-mannose carbohydrates present on the gp120 surface, and possibly binds some of the protein surface as well. Carbohydrate conformation may be influenced by nearby peptide structure. (b) A schematic representation of carbohydrate cluster mimitopes built upon simple backbone designs. Conformations in which the carbohydrates are close enough to resemble the tightly-clustered 2G12 epitope are rare; thus, these mimitopes primarily elicit Abs recognizing single copies of glycan rather than the cluster. Even the rare cluster-specific Abs would lack pockets necessary to accommodate hypothetical gp120 protein elements (dotted surface). (c) The proposed directed-evolution-based solution to the problem of antigen design. A library of replicating glycosylated scaffolds is subjected to evolutionary pressure based on the ability to bind 2G12. The resulting evolved mimitopes contain optimal carbohydrate conformation as well as elements which mimic additional epitope components.
[0048] FIG. 14 (also referred to as “Scheme 1”) depicts SELMA (SELection with Modified Aptamers). The starting point (a) is a synthetic library of ssDNA hairpins containing a stem-loop, an antisense random region (colored hollow bar) and primer sites 1 and 2. Polymerase extension with dNTP's (but alkyne-substituted EdUTP instead of dTTP) creates a dsDNA hairpin library (b) with alkynyl bases incorporated only in the (+)-sense strand. The alkynes are then glycosylated with carbohydrate-azide by CuAAAC chemistry, producing a glycosylated dsDNA library (c) Annealing of primer 1 inside the loop and polymerase extension with all-natural dNTPs results in displacement of the glycosylated strand, creating a library of glyco-ssDNA-dsDNA hybrids (d). The ss-glyco-DNA (+)-sense strand is now the “phenotype”, whereas the tethered dsDNA copy contains no modifications and can undergo efficient PCR, serving as the “genotype”. Thus, the functional structure and its genetic barcode are covalently attached, much as in mRNA display. 19 After selection by solid-phase capture with immobilized 2G12, the best binders (e) are amplified by PCR (or error-prone PCR) using natural dNTPs and primers 1 and 2 affording the (n+1) th -generation library without the hairpin portion (f). The (n+1) th -generation library is then restored to hairpin form (i) by bidirectional polymerase extension with an overhanging biotinylated primer and removal of the biotinylated strand (g-i).
[0049] FIG. 15 depicts a PAGE analysis of the individual steps in a SELMA cycle.
[0050] FIG. 16 depicts the results from the selection process. (a) Preliminary selection results: 2G12-dependent filter binding of clones 4, 16 and 18, the starting library, and arbitrary sequence containing 10 glycosylation sites. (b) Effects of glycosylation, gp120 competition, and single/double-strandedness on 2G12 binding by clone 16 determined by filter binding.
[0051] FIG. 17 depicts a mutagenesis study: Values of K d and fraction bound (F max ) for truncated and mutated clone 16. Entry 1 is unmutated clone 16. Underlined sequence is the random region. S is Man 4 -glycosylated EdU. *The value of K d reported in the text, in entries 1-8 and entries 9-21 were measured with different batches of 2G12, giving slightly different values of K d for the parent clone 16 (text vs. entries 1 vs. 9). The K d values in entries 10-21 should be compared only with entry 9. **K d was much greater than the maximum 2G12 concentration tested and F max was constrained to 1 to fit curve with finite K d value. † Errors reported are the standard error of the curve fit in all cases except entry 1, for which the average of errors in entries 1-8 is reported. FIG. 17 discloses SEQ ID NOS 23-43, respectively, in order of appearance.
[0052] FIG. 18 depicts binding curves for truncation mutants of clone 16/23; entry numbers correspond to sequence numbers in FIG. 17 .
[0053] FIG. 19 depicts binding curves for single mutants of clone 16/23; entry numbers correspond to sequence numbers in FIG. 17 .
[0054] FIG. 20 depicts binding curves for mutants of clone 16/23 glycosylated only in positions 2, 4, and 10; entry numbers correspond to sequence numbers in FIG. 17 .
[0055] FIG. 21 depicts (a) PAGE of click reaction aliquots; and (b) RP-HPLC/ESI-MS chromatogram after 2 h.
[0056] FIG. 22 tabulates masses and abundances of observed species in the chromatogram from FIG. 21 b.
[0057] FIG. 23 tabulates the HPLC gradient used in the purification of 5.
[0058] FIG. 24 depicts additional oligosaccharide-azide compounds (XIII and XIV) of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Overview
[0059] One aspect of the invention relates to a method of directed evolution of carbohydrate-oligonucleotide conjugates. In certain embodiments, a large library of carbohydrate-modified oligonucleotides structures is synthesized, and then a therapeutically-useful monoclonal antibody is used to bind those members of the library which best resemble its native epitope. In certain embodiments, PCR enables amplification or diversification of the best binders from the first library, and the best epitope mimics are selected from subsequent library generations to provide improved binders. In certain embodiments, the carbohydrate-oligonucleotide conjugates obtained from the process present carbohydrates in an environment similar to that of the natural epitope, containing the optimal number of oligosaccharides, with the optimal spacing and conformation, and surrounded by oligonucleotide structures which mimic any necessary peptide component of the natural epitope. In certain embodiments, such a compound, when formulated with the appropriate immunogenic carrier and adjuvant, would constitute a vaccine.
[0060] In certain embodiments, the invention relates to a method of preparing and identifying a vaccine against a disease for which therapeutically-useful antibodies are known to bind to a carbohydrate structure. In certain embodiments, DNA is used as a backbone for carbohydrate vaccines. In certain embodiments, the disease is HIV/AIDS. In certain embodiments, the therapeutically-useful antibody is 2G12. In certain embodiments, the disease is cancer. In certain embodiments, the therapeutically-useful antibody recognizes a cancer antigen. In certain embodiments, the therapeutically-useful antibody is RAV12.
[0061] In certain embodiments, the invention relates to a method of preparing and identifying oligosaccharide-oligonucleotide conjugates which selectively disrupt a physiological glycoprotein-glycoprotein or protein-glycoprotein interaction in which the interaction involves pendant carbohydrate moieties of one or both of the participants.
[0062] In certain embodiments, the invention relates to a method of designing and identifying a novel carbohydrate cluster antigen by attaching carbohydrates to a library of DNA backbones and performing aptamer selection with 2G12. In certain embodiments, the invention relates to a method of designing and identifying glyco-DNAs in which the backbone clusters the carbohydrates in the optimal manner. As opposed to the numerous DNA vaccine approaches, in which DNA is delivered via viral vectors or gold particles and merely codes for a protein antigen, it is important to clarify that, in certain embodiments, the inventive glyco-DNA will be injected as a free molecule in μg quantities, because it is itself the antigen. In certain embodiments, the glyco-DNA fulfills three roles: 1) to orient optimally the attached carbohydrates in a position that mimics their presentation in the true 2G12 epitope, 2) to mimic structurally any possible peptide residues within the 2G12 epitope, and 3) to serve as a built-in adjuvant. In certain embodiments, the functioning of the glyco-DNA as a built-in adjuvant is in contrast with other carbohydrate vaccine approaches, where the carbohydrates were conjugated to proteins or peptides, and mostly failed to elicit anti-carbohydrate antibodies.
[0063] In certain embodiments, the invention relates to a method of eliciting a 2G12-like polyclonal antibody response. Given that monoclonal 2G12 antibody neutralizes a broad-range of HIV-1 strains and has a demonstrated protective effect in non-human primate models of HIV infection, there is good reason to believe that a 2G12-like polyclonal antibody response would also be protective. In certain embodiments, to elicit a 2G12-like response, two challenges must be overcome: 1) to develop an immunogen which structurally and conformationally mimics the 2G12 epitope, and 2) to overcome the poor immunogenicity of the carbohydrate epitope. In certain embodiments, the first challenge is addressed in the inventive methods by using 2G12 to select the best design of carbohydrate cluster from among trillions of possibilities. In certain embodiments, the second challenge is addressed in the inventive methods because the vaccine contains a DNA backbone. DNA is known to be a potent adjuvant, activating numerous Toll receptor pathways.
[0064] In certain embodiments, a method begins with a library of single-stranded DNA hairpins, wherein the 3′ end of each hairpin is a primer for transcription across the randomized DNA template region of the hairpin. In certain embodiments, a primer annealed to the loop region of the hairpin initiates strand displacement-synthesis, thereby (1) liberating the transcribed strand to allow folding, and (2) linearizing the DNA template by making it double-stranded.
[0065] Man 9 GlcNAc 2 oligosaccharides present in the 2G12 epitope of HIV surface protein gp120 have been synthesized. The structures of potentially desirable compounds may be simplified by substituting for the two GlcNAc residues a simple cyclohexyl linker bearing an azide ( FIG. 7 ). FIG. 8 depicts the synthesis of Man 4 -cyclohexyl azide (2) used in the oligonucleotide conjugate selection.
[0066] Glycosyl donor 1 was prepared in seven steps from mannose according to literature methods. Then, the β-mannosylation conditions of Crich were modified by use of excess glycosyl acceptor (as compared to substoichiometric acceptor, as described by Crich). This modification suppressed overglycosylation of the acceptor (at nitrogen) and preserved a good diastereomeric ratio (13:1) at the β-mannose center. The nitrogen was protected as a carbamate to give 2. Sinay coupling with 3 then proceeded to give 4 in 70% isolated yield, after separation of a small amount (1:4) of the minor β-anomer. Global deprotection gave the Man 4 cyclohexylamine intermediate in nearly quantitative yield. This product was subjected to diazotransfer to give the azide 5. In this case, using 10 mol % CuSO 4 catalyst and six equivalents of TfN 3 gave better yields than Wong's method using 1 mol % catalyst and three equivalents of TfN 3 .
Selection Process and Further Investigations
[0067] The ssDNA-dsDNA hybrid library formed according to FIG. 14 a - d was incubated with 2G12, and the 2G12-bound library fraction was captured with protein A beads. The 2G12-bound library fraction was eluted from the beads by thermal denaturation and subjected to PCR with biotinylated primer 2 to give the 2 nd -generation library in purely dsDNA format ( FIGS. 14 f and 14 k ), which gave the expected sharp 80-bp band on the PAGE gel (lane 9). The library was converted back to its hairpin form in three steps: 1) removal of primer-2-derived biotinylated strand, 2) polymerase extension with an overhanging biotinylated strand to afforded 120-bp product ( FIGS. 14 h and 14 k , lane 10), and 3) removal of the biotinylated strand from the 120-bp duplex and polymerase extension in the presence of dATP, dCTP, dGTP and EdUTP, afforded the 2 nd -generation library in duplex hairpin form ( FIG. 14 k , lane 11, identical to lane 2).
[0068] The cycle of library generation and selection was repeated; enrichment was assessed by monitoring the number of PCR cycles required to regenerate the library. Rounds 2, 4, and 6 included a negative selection to remove aptamers that bound to protein A beads. No improvement was observed between rounds 5, 6 and 7, so the selection was terminated and the resulting PCR products were cloned. Twenty clones were randomly selected for sequencing. Seventeen sequences were obtained, which included two pairs of duplicates and fifteen unique sequences with no apparent similarity ( FIG. 12 ). These oligonucleotides contained 7-14 Ts, reflecting the affinity of 2G12 for multiple carbohydrate moieties. These observations suggest that the selection may not have converged on the highest affinity aptamers. Future selections may be improved by limiting the number of positions containing EdU and increasing the stringency of the selection with the inclusion of a competitor.
[0069] Six clones were chosen for further evaluation (4/5, 16/23, 18, 19, 21, 22). The single-stranded portions of these clones were synthesized and glycosylated (see Supporting Information). Both PAGE and mass spectral analysis confirmed that the CuAAAC glycosylation step resulted in a significant portion of fully glycosylated product, though it was generally mixed with species lacking 1-2 glycosylations (see Example 17). All six of the glycosylated clones bound to 2G12 in a filter binding assay. Three clones containing 10 glycosylation sites were chosen for further analysis. Clones 4/5, 16/23 and 18 displayed moderate affinity for 2G12 with values of K d =270±40 nM, 220±50 nM and 330±30 nM, respectively ( FIG. 16 a ). Importantly, no binding was observed with the initial library or with a random oligonucleotide containing ten glycosylated residues. Therefore 2G12 binding is not simply the result of polyvalent interactions with multiple glycosylated residues.
[0070] The binding determinants of clone 16/23 were further dissected ( FIG. 16 b ). The duplex form of clone 16/23 bound 2G12 significantly less efficiently than the single stranded version. No binding was observed in the absence of glycosylation. Gratifyingly, binding was significantly diminished in the presence of gp120, indicating that gp120 and clone 16/23 compete for the same site on 2G12.
[0071] A series of mutagenesis experiments on clone 16/23 were conducted, starting with truncation at both the 5′ and 3′ ends in short increments ( FIG. 17 , entries 1-8). The extreme ends are not essential for binding to 2G12; however, significant reduction in affinity was observed when the truncations extended beyond the first and last glycosylation sites. Point mutagenesis was performed, replacing each glycosylated EdU residue with cytosine ( FIG. 17 , entries 9-21). Seven of these mutations produced little change in the value of K d ; however, mutations in the 2 nd , 4 th , and 10 th glycosylation positions (entries 11, 13 and 19) caused a drastic loss of binding (K d >>800 nM). Glycoaptamers containing only these three glycoslyation sites (entries 20 and 21) failed to bind to 2G12, indicating that glycoslyation of these sites is necessary but not sufficient for 2G12 binding. Glycosylation at the remaining sites may be important for the gross conformational features of the aptamer. Both of these findings are consistent with mutagenesis studies that showed only a small subset of gp120's dozen high-mannose glycans are required for 2G12 recognition. Significantly, these results are the first to demonstrate that the specific arrangement of carbohydrates—rather than high carbohydrate density or a large number of copies—is responsible for good mimicry of the epitope.
[0072] In certain embodiments, this work demonstrates the feasibility of using directed evolution to optimize the clustering of glycans for multivalent interaction with a target protein.
Exemplary Methods of the Invention
[0073] In certain embodiments, the invention relates to a method, comprising the steps of:
(a) combining an oligonucleotide, a first DNA polymerase, and a plurality of deoxyribonucleotide triphosphates,
wherein the oligonucleotide comprises a first primer binding site on the 5′ end, a randomized region, and a stem-loop region; the randomized region is located between the first primer binding site and the stem-loop region; the stem-loop region comprises a second primer binding site; and at least one of the deoxyribonucleotide triphosphates comprises a reactive substituent;
thereby forming an extended oligonucleotide comprising an original strand and an extended strand, wherein the extended strand comprises at least one reactive substituent; (b) combining a plurality of modifying compounds and the extended oligonucleotide under reaction conditions, thereby forming a modified extended oligonucleotide comprising the original strand and a modified extended strand; and (c) combining a primer complementary to the second primer binding site, a second DNA polymerase, the modified extended oligonucleotide, and a plurality of deoxyribonucleotide triphosphates thereby creating a duplex with the original strand and displacing the modified extended strand.
[0084] In certain embodiments, the invention relates to a method, comprising the steps of:
(a) combining a plurality of oligonucleotides, a first DNA polymerase, and a plurality of deoxyribonucleotide triphosphates,
wherein the oligonucleotides comprise a first primer binding site on the 5′ end, a randomized region, and a stem-loop region; the randomized region is located between the first primer binding site and the stem-loop region; the stem-loop region comprises a second primer binding site; and at least one of the deoxyribonucleotide triphosphates comprises a reactive substituent;
thereby forming a plurality of extended oligonucleotides comprising an original strand and an extended strand, wherein the extended strand comprises at least one reactive substituent; (b) combining a plurality of modifying compounds and the plurality of extended oligonucleotides under reaction conditions, thereby forming a plurality of modified extended oligonucleotides comprising the original strand and a modified extended strand; and (c) combining a plurality of primers complementary to the second primer binding site, a second DNA polymerase, the plurality of modified extended oligonucleotides, and a plurality of deoxyribonucleotide triphosphates thereby creating duplexes with the original strands and displacing the modified extended strands.
[0096] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein oligonucleotide is in the form of a partial stem-loop.
[0097] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the randomized region consists of about 15-35, about 15, about 20, about 25, about 30, or about 35 nucleobases.
[0098] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the randomized region consists of about 25 nucleobases.
[0099] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the deoxyribonucleotide triphosphate comprising a reactive substituent is an unnatural deoxyribonucleotide triphosphate.
[0100] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the reactive substituent is ethynyl.
[0101] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the deoxyribonucleotide triphosphate comprising a reactive substituent is 5-ethynyl-deoxyuridine triphosphate.
[0102] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein no thymidine triphosphate is used in step (a).
[0103] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the extended oligonucleotide has a hairpin configuration.
[0104] In certain embodiments, the invention relates to any one of the aforementioned methods, further comprising the step of purifying the extended oligonucleotide, thereby forming a purified extended oligonucleotide.
[0105] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound comprises an azide.
[0106] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound comprises an azide and a sugar moiety.
[0107] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is represented by the following formula:
[0000]
[0108] wherein
[0109] A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties;
[0110] L represents a linker;
[0111] the linker is a linear or branched C 2 -C 18 -alkanediyl; a linear or branched C 2 -C 30 -alkanediyl optionally interrupted by one or more non-adjacent —O—, one or more —NR—, or one or more —C(═O)—; 1,3-cyclohexanediyl; 1,4-cyclohexanediyl; 4-methyl-1,3-cyclohexanediyl; an aryl diradical; or a heteroaryl diradical; any of which may be optionally substituted; and
[0112] R represents H or alkyl.
[0113] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is represented by formula III
[0000]
[0114] wherein A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties.
[0115] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is:
[0000]
[0116] wherein
[0117] L represents a linker;
[0118] the linker is a linear or branched C 2 -C 18 -alkanediyl; a linear or branched C 2 -C 30 -alkanediyl optionally interrupted by one or more non-adjacent —O—, one or more —NR—, or one or more —C(═O)—; 1,3-cyclohexanediyl; 1,4-cyclohexanediyl; 4-methyl-1,3-cyclohexanediyl; an aryl diradical; a monosaccharide diradical; a disaccharide diradical; or a heteroaryl diradical; any of which may be optionally substituted; and
[0119] R represents H or alkyl.
[0120] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is represented by formula I or formula II
[0000]
[0121] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is selected from the group consisting of
[0000]
[0122] wherein A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties.
[0123] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the reaction conditions include copper catalysis or ruthenium catalysis.
[0124] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the reaction conditions include copper catalysis.
[0125] In certain embodiments, the invention relates to a method, comprising the steps of:
[0126] combining a plurality of modified single-stranded oligonucleotides and a target protein;
[0127] isolating the modified single-stranded oligonucleotides that bind to the target protein, thereby identifying a plurality of selected oligonucleotides;
[0128] amplifying the plurality of selected oligonucleotides, thereby forming a plurality of double-stranded oligonucleotides; and
[0129] preparing from the plurality of double-stranded oligonucleotides a plurality of regenerated selected oligonucleotides.
[0130] In certain embodiments, the invention relates to any one of the aforementioned methods, further comprising the step of exposing the plurality of regenerated selected oligonucleotides to the target protein.
[0131] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the target protein is an antibody.
[0132] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the target protein is a non-human antibody.
[0133] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the target protein is the 2G12 antibody.
[0134] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modification comprises a sugar moiety attached to the oligonucleotide.
[0135] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modification comprises a sugar moiety attached to the oligonucleotide via a triazole moiety.
[0136] In certain embodiments, the invention relates to a method, comprising the steps of:
(a) combining a plurality of oligonucleotides, a first DNA polymerase, and a plurality of deoxyribonucleotide triphosphates,
wherein the oligonucleotides comprise a first primer binding site on the 5′ end, a randomized region, and a stem-loop region; the randomized region is located between the first primer binding site and the stem-loop region; the stem-loop region comprises a second primer binding site; and at least one of the deoxyribonucleotide triphosphates comprises a reactive substituent;
thereby forming a plurality of extended oligonucleotides comprising an original strand and an extended strand, wherein the extended strand comprises at least one reactive substituent; (b) combining a plurality of modifying compounds and the plurality of extended oligonucleotides under reaction conditions, thereby forming a plurality of modified extended oligonucleotides comprising the original strand and a modified extended strand; (c) combining a plurality of primers complementary to the second primer binding site, a second DNA polymerase, the plurality of modified extended oligonucleotides, and a plurality of deoxyribonucleotide triphosphates thereby creating duplexes with the original strands, displacing the modified extended strands, and forming a plurality of modified single-stranded oligonucleotides; (d) combining the plurality of modified single-stranded oligonucleotides and a target protein; (e) isolating the modified single-stranded oligonucleotides that bind to the target protein, thereby identifying a plurality of selected oligonucleotides; (f) amplifying the plurality of selected oligonucleotides, thereby forming a plurality of complementary oligonucleotides; and (g) preparing a plurality of regenerated selected oligonucleotides from the plurality of complementary oligonucleotides.
[0152] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the oligonucleotide has the form of a partial stem-loop.
[0153] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the randomized region consists of about 15-35, about 15, about 20, about 25, about 30, or about 35 nucleobases.
[0154] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the randomized region consists of about 25 nucleobases.
[0155] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the deoxyribonucleotide triphosphate comprising a reactive substituent is an unnatural deoxyribonucleotide triphosphate.
[0156] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the reactive substituent is ethynyl.
[0157] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the deoxyribonucleotide triphosphate comprising a reactive substituent is 5-ethynyl-deoxyuridine triphosphate.
[0158] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein no thymidine triphosphate is used in step (a).
[0159] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the extended oligonucleotide has a hairpin configuration.
[0160] In certain embodiments, the invention relates to any one of the aforementioned methods, further comprising the step of purifying the extended oligonucleotide, thereby forming a purified extended oligonucleotide.
[0161] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound comprises an azide.
[0162] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound comprises an azide and a sugar moiety.
[0163] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is represented by the following formula:
[0000]
[0164] wherein
[0165] A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties;
[0166] L represents a linker;
[0167] the linker is a linear or branched C 2 -C 18 -alkanediyl; a linear or branched C 2 -C 30 -alkanediyl optionally interrupted by one or more non-adjacent —O—, one or more —NR—, or one or more —C(═O)—; 1,3-cyclohexanediyl; 1,4-cyclohexanediyl; 4-methyl-1,3-cyclohexanediyl; an aryl diradical; a monosaccharide diradical; a disaccharide diradical; or a heteroaryl diradical; any of which may be optionally substituted; and
[0168] R represents H or alkyl.
[0169] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is represented by formula III
[0000]
[0170] wherein A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties.
[0171] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is represented by one of the following formulae:
[0000]
[0172] wherein
[0173] L represents a linker;
[0174] the linker is a linear or branched C 2 -C 18 -alkanediyl; a linear or branched C 2 -C 30 -alkanediyl optionally interrupted by one or more non-adjacent —O—, one or more —NR—, or one or more —C(═O)—; 1,3-cyclohexanediyl; 1,4-cyclohexanediyl; 4-methyl-1,3-cyclohexanediyl; an aryl diradical; a monosaccharide diradical; a disaccharide diradical; or a heteroaryl diradical; any of which may be optionally substituted; and
[0175] R represents H or alkyl.
[0176] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is represented by formula I or formula II
[0000]
[0177] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the modifying compound is selected from the group consisting of
[0000]
[0178] wherein A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties.
[0179] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the reaction conditions include copper catalysis or ruthenium catalysis.
[0180] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the reaction conditions include copper catalysis.
[0181] In certain embodiments, the invention relates to any one of the aforementioned methods, further comprising the step of exposing the plurality of regenerated selected oligonucleotides to the target protein.
[0182] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the target protein is an antibody.
[0183] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the target protein is a non-human antibody.
[0184] In certain embodiments, the invention relates to any one of the aforementioned methods, wherein the target protein is the 2G12 antibody.
Exemplary Compounds of the Invention
[0185] In certain embodiments, the invention relates to a compound comprising a sugar moiety and an azide.
[0186] In certain embodiments, the invention relates to a compound of the following formula:
[0000]
[0187] wherein
[0188] A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties;
[0189] L represents a linker;
[0190] the linker is a linear or branched C 2 -C 18 -alkanediyl; a linear or branched C 2 -C 30 -alkanediyl optionally interrupted by one or more non-adjacent —O—, one or more —NR—, or one or more —C(═O)—; 1,3-cyclohexanediyl; 1,4-cyclohexanediyl; 4-methyl-1,3-cyclohexanediyl; an aryl diradical; a monosaccharide diradical; a disaccharide diradical; or a heteroaryl diradical; any of which may be optionally substituted; and
[0191] R represents H or alkyl.
[0192] In certain embodiments, the invention relates to a compound of formula III
[0000]
[0193] wherein A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties.
[0194] In certain embodiments, the invention relates to any one of the aforementioned compounds, wherein the compound is represented by one of the following formulae:
[0000]
[0195] wherein
[0196] L represents a linker;
[0197] the linker is a linear or branched C 2 -C 18 -alkanediyl; a linear or branched C 2 -C 30 -alkanediyl optionally interrupted by one or more non-adjacent —O—, one or more —NR—, or one or more —C(═O)—; 1,3-cyclohexanediyl; 1,4-cyclohexanediyl; 4-methyl-1,3-cyclohexanediyl; an aryl diradical; a monosaccharide diradical; a disaccharide diradical; or a heteroaryl diradical; any of which may be optionally substituted; and
[0198] R represents H or alkyl.
[0199] In certain embodiments, the invention relates to any one of the aforementioned compounds, wherein the compound is represented by formula I or formula II
[0000]
[0200] In certain embodiments, the invention relates to any one of the aforementioned compounds, wherein the compound is selected from the group consisting of
[0000]
[0201] wherein A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties.
Exemplary Oligonucleotides of the Invention
[0202] In certain embodiments, the invention relates to an oligonucleotide, wherein the oligonucleotide comprises at least one non-natural deoxynucleoside; and the non-natural deoxynucleoside comprises an oligosaccharide moiety and a triazole moiety.
[0203] In certain embodiments, the invention relates to an oligonucleotide, wherein the oligonucleotide comprises at least one non-natural deoxynucleoside of the following formula:
[0000]
[0204] wherein
[0205] A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties;
[0206] L represents a linker;
[0207] the linker is a linear or branched C 2 -C 18 -alkanediyl; a linear or branched C 2 -C 30 -alkanediyl optionally interrupted by one or more non-adjacent —O—, one or more —NR—, or one or more —C(═O)—; 1,3-cyclohexanediyl; 1,4-cyclohexanediyl; 4-methyl-1,3-cyclohexanediyl; an aryl diradical; a monosaccharide diradical; a disaccharide diradical; or a heteroaryl diradical; any of which may be optionally substituted; and
[0208] R represents H or alkyl.
[0209] In certain embodiments, the invention relates to an oligonucleotide, wherein the oligonucleotide comprises at least one non-natural deoxynucleoside of the following formula
[0000]
[0210] wherein
[0211] A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties;
[0212] L represents a linker;
[0213] the linker is a linear or branched C 2 -C 18 -alkanediyl; a linear or branched C 2 -C 30 -alkanediyl optionally interrupted by one or more non-adjacent —O—, one or more —NR—, or one or more —C(═O)—; 1,3-cyclohexanediyl; 1,4-cyclohexanediyl; 4-methyl-1,3-cyclohexanediyl; an aryl diradical; a monosaccharide diradical; a disaccharide diradical; or a heteroaryl diradical; any of which may be optionally substituted; and
[0214] R represents H or alkyl.
[0215] In certain embodiments, the invention relates to an oligonucleotide, wherein the oligonucleotide comprises at least one non-natural deoxynucleoside of formula IV
[0000]
[0216] wherein A represents a branched or unbranched oligosaccharide consisting of about 3 to about 15 saccharide moieties.
[0217] In certain embodiments, the invention relates to any one of the aforementioned oligonucleotides, consisting of 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, or 56 nucleobases.
Exemplary Formulations of the Invention
[0218] In certain embodiments, the invention relates to a formulation, comprising:
[0219] any one of the aforementioned compounds or oligonucleotides; and
[0220] an immunogenic carrier.
[0221] In certain embodiments, the invention relates to a formulation, consisting essentially of:
[0222] any one of the aforementioned compounds or oligonucleotides; and
[0223] an immunogenic carrier.
[0224] In certain embodiments, the invention relates to a formulation, consisting of:
[0225] any one of the aforementioned compounds or oligonucleotides; and
[0226] an immunogenic carrier.
[0227] In certain embodiments, the immunogenic carrier helps elicit a response from the immune system of a mammal upon administration of the formulation to a mammal in need thereof.
[0228] In certain embodiments, the immunogenic carrier is coupled to any one of the aforementioned compositions.
[0229] In certain embodiments, the immunogenic carrier is Keyhold Limpet Hemocyanin (KLH). KLH is one of the most widely employed carrier proteins for this purpose. KLH is an effective carrier protein for several reasons. Its large size and numerous epitopes generate a substantial immune response, and the abundance of lysine residues for coupling haptens allows a high hapten:carrier protein ratio, increasing the likelihood of generating hapten-specific antibodies. In addition, because KLH is derived from the limpet, a gastropod, it is phylogenetically distant from mammalian proteins, thus reducing false positives in immunologically-based research techniques in mammalian model organisms.
[0230] In certain embodiments, the immunogenic carrier is the outer membrane protein complex (OMPC) of Neisseria meningitidis.
[0231] In certain embodiments, the formulation further comprises a T-helper epitope. In certain embodiments, the T-helper epitope is coupled to any one of the aforementioned compositions.
[0232] In certain embodiments, the invention relates to a formulation, comprising:
[0233] an adjuvant; and
[0234] any one of the aforementioned compounds or oligonucleotides.
[0235] In certain embodiments, the invention relates to a formulation, consisting essentially of:
[0236] an adjuvant; and
[0237] any one of the aforementioned compounds or oligonucleotides.
[0238] In certain embodiments, the invention relates to a formulation, consisting of:
[0239] an adjuvant; and
[0240] any one of the aforementioned compounds or oligonucleotides.
[0241] In certain embodiments, the adjuvant is any substance that acts to accelerate, prolong, or enhance antigen-specific immune responses when used in combination with any one of the aforementioned compositions.
[0242] In certain embodiments, the adjuvant comprises an aluminum salt. In certain embodiments, the adjuvant comprises aluminum hydroxide or aluminum phosphate.
[0243] In certain embodiments, the adjuvant comprises a phosphate.
[0244] In certain embodiments, the adjuvant comprises squalene.
EXEMPLIFICATION
[0245] The invention now being generally described, it will be more readily understood by reference to the following examples which are included merely for purposes of illustration of certain aspects and embodiments of the present invention, and are not intended to limit the invention.
Example 1
Oligosaccharide Synthesis
[0246] Materials and Methods
[0247] Reagents were purchased from Sigma-Aldrich, Acros Organics, Fluka, Alfa Aesar, or Strem, and used without further purification unless otherwise noted. Toluene, THF, and DCM were dried by passage through activated alumina columns and stored under argon gas. Acetonitrile was distilled over calcium hydride. Glassware was flame-dried or dried in a 150° C. oven. Silicycle Siliaflash® P60 silica was used for column chromatography. All 1 H and 13 C NMR spectra were obtained on a Varian iNova 400 instrument in CDCl 3 and internally referenced to TMS; or D 2 O, internally or externally referenced to sodium 3-(trimethylsilyl)propanesulfonate. Chemical shifts are reported in parts per million (ppm), and coupling constants are reported in Hz. LC/MS analysis was performed on a Waters Acquity UPLC chromatograph with a reverse phase C 18 or C 8 column, and a Waters Micromass Z/Q mass detector. Optical rotation was measured using a Jasco digital polarimeter Infrared spectra were obtained using a Varian 640-IR spectrometer with a ZnSe ATR.
[0248] Experimental Procedures
[0000]
[0249] To a 50 mL flask was added 717 mg (1.22 mmol) of starting material 1. This was cooled to −78° C. and azeotroped with toluene twice. Then, 8 mL of dry dichloromethane, along with 606 mg (2.44 mmol) of tri tert-butylpyrimidine and freshly flame-dried powdered 4-Å molecular sieves were added. This was cooled to −78° C. and allowed to stir for 30 minutes. After this time, 0.16 mL (0.978 mmol) of distilled triflic anhydride was added slowly. This was allowed to react for 30 minutes, then 630 mg (2.44 mmol) of acceptor in 8.5 mL of dichloromethane was added dropwise. After 1 hour, the reaction was allowed to slowly warm to −20° C., and quenched with saturated aqueous NaHCO 3 solution, then filtered through Celite. The solution was washed with 50 mL of saturated aqueous NaHCO 3 solution, then the aqueous phase was extracted with 3×50 mL ethyl acetate. The combined organic layers were dried with MgSO 4 , filtered and concentrated. Crude mass was 2.00 g. Purified by flash column chromatography with 1:2:1---->1:1.5:1 ethyl acetate/hexanes/dichloromethane. Final mass was 638 mg (0.891 mmol, 91%) based on Tf 2 O) of 1b as a white foam. 1 H NMR (400 MHz, CDCl 3 ): δ 7.89 (d, 2H, J=7.3 Hz), 7.60-7.17 (m, 15H), 6.82 (d, 2H, J=8.6 Hz), 5.59 (s, 1H), 4.93 (d, 1H, J=12.2 Hz), 4.83 (d, 1H, J=12.2 Hz), 4.55 (m, 4H), 4.26 (dd, 1H, J=4.9, 10.4 Hz), 4.17 (app t, 1H), 3.90 (app t, 1H), 3.79 (s, 3H), 3.79 (m, 1H), 3.59 (m, 1H), 3.53 (dd, 1H, J=9.8 Hz, 3.1 Hz), 3.27 (m, 1H), 3.18 (m, 1H), 1.97 (m, 1H), 1.85 (m, 3H), 1.40 (m, 1H), 1.24 (m, 3H). 13 C-NMR (100 MHz, CDCl3, selected signals): δ 29.5, 31.0, 51.7, 55.4, 67.7, 68.7, 72.1, 74.7, 75.6, 76.1, 77.7, 78.6, 100.2, 101.5, 113.8, 126.2, 127.0, 127.7, 128.2, 128.3, 128.8, 129.0, 129.3, 130.4, 132.8, 137.7, 138.5, 141.1, 159.2. IR (cm −1 ): 3267 (br), 2936, 2863, 1610 (s), 1512, 1448, 1325, 1246, 1159, 1076. HRMS (ESI+): calcd. for C 40 H 46 NO 9 S + [M+H + ] 716.2893. found 716.2892.
[0000]
[0250] To a 25-mL round bottom flask was added 213 mg (5.32 mmol) of 60% wt NaH powder, and this was cooled to 0° C. A solution of 760 mg (1.06 mmol) of 1b in 8.5 mL of THF was added slowly. This was allowed to stir for 30 minutes, then 0.269 mL (3.19 mmol) of methyl chloroformate was added, along with 130 mg (1.06 mmol) of recrystallized DMAP. The cooling bath was removed, and the reaction progressed for 17 hours. After this time, the flask was cooled to 0° C. and quenched with saturated aqueous NH 4 Cl solution. The organic phase was washed with 40 mL of NH 4 Cl solution, then the aqueous phase was extracted with 3×40 mL of DCM. The combined organic layers were dried with MgSO 4 , filtered and concentrated. Crude mass was about 1 g. Purification by flash column chromatograph in 1:2 ethyl acetate/hexanes gave a final mass of 724 mg (0.936 mmol, 88%) of 1c as a white foam. 1 H NMR (400 MHz, CDCl 3 ): δ 7.92 (d, 2H, J=8.6 Hz), 7.62 (app t, 1H), 7.57-7.44 (m, 6H), 7.40-7.27 (m, 6H), 7.20 (d, 2H, J=8.5 Hz), 6.83 (d, 2H, J=8.6 Hz), 5.61 (s, 1H), 4.98 (d, 1H, J=12.8 Hz), 4.88 (d, 1H, J=12.2 Hz), 4.61 (d, 1H, J=12.2 Hz), 4.55 (s, 1H), 4.53 (d, 1H, J=˜12 Hz), 4.44 (m, 1H), 4.31 (dd, 1H, J=10.4 Hz, 4.9 Hz), 4.20 (app t, 1H), 3.94 (app t, 1H), 3.83 (d, 1H, J=2.7 Hz), 3.80 (s, 3H), 3.66 (s, 3H), 3.66 (m, 1H), 3.56 (dd, 1H, J=9.8 Hz, 2.4 Hz), 3.31 (m, 1H), 2.27 (m, 3H), 2.05 (m, 1H), 1.87 (m, 2H), 1.58 (m, 1H), 1.41 (m, 1H). 13 C-NMR (100 MHz, CDCl3, selected signals): δ 28.6, 31.7, 33.3, 53.6, 55.4, 58.6, 67.7, 68.7, 72.1, 74.7, 76.1, 76.3, 77.7, 78.7, 100.3, 101.5, 113.8, 126.2, 127.6, 128.0, 128.2, 128.3, 128.9, 129.3, 130.5, 133.5, 137.7, 138.5, 140.3, 152.7, 159.2. IR (cm −1 ): 2939, 2866, 1731, 1512, 1449, 1356, 1269, 1247, 1169, 1085, 1045, 733, 697. HRMS (ESI+): calcd. for C 42 H 48 NO 11 S + [M+H + ] 774.2948. found 774.2961.
[0000]
[0251] To a flask containing 2.04 g (2.64 mmol) of 1c was added 28 mL of DCM and 1.55 mL of 1 M pH 7 phosphate buffer. This was cooled to 0° C., and 1.44 g (6.34 mmol) of DDQ was added. This was allowed to stir for 1 hour, then quenched with aqueous NaHCO 3 solution. This was diluted with DCM, and the organic phase was washed with 375 mL of water. The aqueous phase was extracted with 3×300 mL DCM, then the combined organic layers were dried with MgSO 4 , filtered, and concentrated. Purification by flash chromatography (1:2 ethyl acetate/hexanes) afforded 1.53 g (2.34 mmol, 87%) of 2 as an off-white foam. 1 H NMR (400 MHz, CDCl 3 ): δ 7.90 (d, 2H, J=7.3 Hz), 7.60 (app t, 1H) 7.57-7.27 (m, 12H), 5.52 (s, 1H), 5.05 (d, 1H, J=11.6 Hz), 4.67 (s, 1H), 4.65 (d, 1H, J=12.2), 4.43 (m, 1H), 4.29 (dd, 1H, J=10.4 Hz, 4.9 Hz), 3.92-3.63 (m, 5H), 3.64 (s, 3H), 3.31 (m, 1H), 2.36-2.11 (m, 5H), 1.86 (m, 2H), 1.61-1.40 (m, 2H). 13 C-NMR (100 MHz, CDCl3, selected signals): δ 28.5, 31.7, 33.4, 53.6, 58.5, 67.2, 68.7, 70.9, 75.8, 76.4, 78.9, 79.4, 100.3, 102.1, 126.4, 120.0, 128.1, 128.4, 128.5, 128.6, 128.9, 129.2, 133.5, 137.3, 138.2, 140.3, 152.6. IR (cm −1 ): 3528 (br), 2949, 2872, 1733, 1449, 1358, 1272, 1171, 1090, 751, 700. HRMS (ESI+): calcd. for C 34 H 40 NO 10 S + [M+H + ] 654.2373. found 654.2366.
[0000]
[0252] 210 mg (0.333 mmol) of 2 and 700 mg of 3 (0.500 mmol) in a 25 mL flask were dissolved in toluene and cooled to −78° C. Vacuum was applied and the cooling bath was removed and allowed to warm to room temperature as the toluene evaporated. This procedure was repeated twice. The residue was redissolved in 12 mL of acetonitrile, and freshly flame-dried 4-Å molecular sieves were added, and this was allowed to stir for 1 hour. The flask was then wrapped in foil, cooled to 0° C., and 525 mg (0.799 mmol) Sinaÿ reagent (p-BrC 6 H 4 ) 3 N + SbCl 6 − , was added. This was allowed to react at 0° C. for 30 minutes, then at room temperature for 30 minutes. After this time, 1 mL triethylamine was added, and the reaction was filtered through Celite and concentrated in vacuo. The crude residue was purified by flash chromatography with 1:3.5:1 ethyl acetate/hexanes/DCM to give 440 mg (0.230 mmol, 69%) 4 as a white foam. 1 H NMR (400 MHz, CDCl 3 ): δ 7.92 (d, 2H, J=6.4 Hz), 7.62 (t, 1H), 7.53 (app t, 2H), 7.43 (d, 2H, J=7.3 Hz), 7.39 (d, 2H, J=7.0 Hz), 7.37-6.96 (m, 50H+residual CHCl 3 ), 6.93 (app t, 1H), 5.53 (s, 1H), 5.40 (s, 1H), 5.34 (s, 1H), 5.24 (s, 1H), 4.98 (s, 1H), 4.9-3.6 (complex region), 3.66 (s, 3H), 3.60-3.40 (m, 4H), 3.33 (br d, 1H, J=11.0), 3.13 (m, 1H), 2.24 (m, 2H), 2.12, (s, 3H), 1.84 (m, 3H), 1.51 (m, 1H), 1.26 (m, 1H+grease). 13 C-NMR (100 MHz, CDCl 3 , selected signals): δ 28.5, 33.2, 53.5, 58.5, 67.3, 94.4, 99.6, 99.9, 100.0, 101.2, 126.0, 133.5, 133.5, 137.3, 138.2, 138.5. IR (cm −1 ): 3029, 2863, 1735, 1452, 1360, 1085, 1055, 736, 697. HRMS (ESI+): calcd. for C 117 H 126 NO 26 S + [M+H + ] 1992.8289. found 1992.8224.
[0000]
[0253] 100 mg (0.050 mmol) 4 was dissolved in 12 mL anhydrous methanol and 0.500 mL (2.00 mmol) of 25% wt NaOMe solution in methanol was added. After 3 hours, Amberlite IR-120 H + ion exchange resin was added until the solution was neutral (NOTE: avoid acidifying beyond pH 4). The mixture was filtered through Celite® and concentrated to give 97 mg crude material. Purification by flash chromatography in 40% ethyl acetate/hexanes gave 87.6 mg (0.0463 mmol, 93%) product 4b as a white foam. 1 H NMR (400 MHz, CDCl 3 ): δ 7.89 (d, 2H, J=8 Hz), 7.60 (app t, 1H), 7.55 (m, 2H), 7.43 (d, 2H, J=7.9 Hz) 7.40-7.07 (m, 52H+residual CHCl 3 ), 6.92 (app t, 1H) 5.41 (s, 1H), 5.33 (s, 1H), 5.26 (s, 1H), 5.05 (s, 1H), 4.82-3.20 (complex region), 3.13 (m, 2H), 2.34 (s, 1H), 1.91 (m, 1H), 1.82 (m, 2H), 1.67 (m, 1H), 1.40 (m, 1H), 1.2-1.1 (m, 3H). 13 C-NMR (100 MHz, CDCl3, selected signals): δ 31.1, 51.7, 67.4, 68.6, 69.2, 71.4, 72.2, 72.4, 73.3, 80.3, 99.9, 101.3, 126.0, 127.0, 127.2, 127.5, 127.7, 127.8, 127.9, 128.0, 128.1, 128.2, 128.3, 128.4, 128.5, 128.6, 129.3, 132.8, 138.2, 138.6. IR (cm −1 ): 3460 (br) 3261 (br) 3063, 3027, 2920, 2862, 1453, 1362, 1073, 1055, 737, 697. HRMS (ESI+): calcd. for C 113 H 121 NO 23 S + [M+H + ] 1892.8128. found 1892.8042.
[0000]
[0254] Along with a stream of N 2 , ammonia gas was condensed against a −78° C. cold finger into a −78° C.-cooled 500 mL 3-necked flask until ˜200 mL had accumulated. 320 mg (13.8 mmol) Na 0 was then added, and the resulting blue solution was monitored for 1 hour to ensure that color did not disappear. 131 mg (0.0691 mmol) 4b in 3 mL THF was then added, and this was allowed to react at −78° C. for 2 hours. 1.11 g (20.7 mmol) of solid NH 4 Cl was added portionwise, the cooling bath was removed, and the ammonia was blown off under a stream of nitrogen. The crude product was dissolved in minimal water and desalted by passage through a Biogel P-2 size exclusion gel column to give 51.8 mg (0.0678 mmol, 98%) compound 4c as a brittle colorless glass. 1 H NMR (400 MHz, D 2 O): δ 5.35 (s, 1H), 5.30 (s, 1H), 5.04 (s, 1H), 4.81 (s, 1H), 4.15-3.60 (m, 24H), 3.39 (m, 1H), 3.19 (m, 1H), 2.20-2.03 (m, 4H), 1.5-1.3 (m, 4H). 13 C-NMR (100 MHz, CDCl3, selected signals): δ 30.9, 31.0, 31.9, 33.2, 52.0, 63.8, 69.0, 69.7, 69.8, 72.8, 73.2, 73.6, 76.1, 76.2, 78.8, 81.4, 83.5, 100.7, 103.5, 105.1. IR (cm −1 ): 3300 (v br), 2925, 1739, 1629, 1448, 1363, 1030. HRMS (ESI+): calcd. for C 30 H 54 NO 21 + [M+H + ] 764.3188. found 764.3184.
[0000]
[0255] 15.2 mg (0.234 mmol) sodium azide was suspended in a vial in 50 μL each of DCM and water. This was cooled to 0° C., and 20 μL (0.117 mmol) of triflic anhydride was added. After 2 hours, this was quenched with aqueous NaHCO 3 solution, and the aqueous layer was extracted twice with DCM. The combined organic layers containing triflyl azide were reduced to ˜0.1 mL under vacuum.
[0256] Into a 5 mL flask containing 9 mg (0.0117 mmol) of 4c was added 125 μL water and 57 μL of 0.02 M aqueous CuSO 4 solution (0.0011 mmol). The triflyl azide solution (prepared above) was then added, followed by 0.5 mL of methanol. After 2.5 hours, the reaction was quenched with 10 mg (10 eq) solid NaHCO 3 and concentrated in vacuo. The crude material was desalted on a Biogel P-2 size exclusion gel column, and then purified by HPLC (gradient shown in FIG. 23 ). Product was detected by UV at 220 nm and eluted at ˜18 minutes. Concentration of fractions afforded 6.6 mg (0.00842 mmol, 72%) of Man 4 -azide (5), a colorless glass. 1 H NMR (400 MHz, D 2 O): δ 5.36 (s, 1H), 5.31 (s, 1H), 5.05 (s, 1H), 4.80 (s, 1H), 4.10-3.62 (m, 25H), 3.53-3.47 (m, 1H), 3.42-3.38 (m, 1H), 3.34 (s residual MeOH), 2.1-1.95 (m, 4H), 1.5-1.3 (m, 4H). 13 C-NMR (100 MHz, D 2 O, selected signals): δ 31.1, 31.2, 31.5, 32.9, 61.7, 63.8, 63.9, 69.0, 69.7, 69.8, 72.8, 73.2, 73.7, 76.1, 76.2, 78.9, 79.0, 81.4, 81.6, 83.5, 100.6, 103.5, 105.1. IR (cm −1 ): 3344, 2933, 2096, 1629, 1367, 1124, 1055. HRMS (ESI+): calcd. for C 40 H 52 N 3 O 21 + [M+H + ] 790.3093. found 790.3087.
Example 2
General Biological Materials
[0257] The original oligonucleotide library, PCR primers and the library regeneration primer were purchased from Integrated DNA Technologies. A complete list of primers is in FIG. 1 . Vent polymerase, Vent(exo) polymerase, Bst polymerase, T4 polynucleotide kinase, Exonuclease I, Taq polymerase and streptavidin magnetic beads were purchased from New England Biolabs. Centrisep desalting columns were purchased from Princeton Separations. Sephadex G-50 superfine resin was purchased from GE Healthcare. Antibody 2G12 was purchased from Immune Technology Corp. Protein A Dynabeads and a TOPO-TA cloning kit were purchased from Invitrogen. ATP (γ- 32 P) was purchased from Perkin Elmer. Synthetic oligos were purchased from Integrated DNA Technologies of ELLA Biotech.
Example 3
Incorporation of Alkyne-Containing Thymidine Analogues
[0258] The original oligonucleotide library consists of a stem-loop region connected to a typical aptamer library—a randomized portion flanked by primer regions for aptamerfor and aptamerrev ( FIG. 1 ). In a PCR tube, 40 pmol of library, 2.5 μL 10× Thermopol buffer (New England Biolabs), and 17 μL autoclaved H 2 O were combined, after which the temperature was raised to 95° C. for 15 seconds and allowed to cool to room temperature. Then, a 0.5 μL of a solution containing 10 mM deoxyadenosine triphosphate, 10 mM deoxycytosine triphosphate, 10 mM deoxyguanosine triphosphate, and 10 mM alkyne-containing thymidine triphosphate analogue 5-ethynyl-deoxyuridine (EdU) triphosphate (synthesis in Example 19) was added to afford a final concentration of 200 μM each. 8 U of Bst polymerase (large fragment) was added to the reaction, yielding a final reaction volume of 25 μL. The reaction was mixed and incubated at 60° C. for 2 minutes.
Example 4
Click Reaction
[0259] The reaction was diluted to 50 μL with H 2 O and transferred to a cap-less 0.5 mL microcentrifuge tube. 5 μL of 10 mM tris(3-hydroxypropyl-4-triazolylmethyl)amine (THPTA), 2 μL of 25 mM CuSO 4 , and 5 μL of 35 mM mannose sugar-azide was added and the solution was mixed by pipetting. Then, 2 μL of freshly dissolved 250 mM sodium ascorbate was added followed by immediate mixing by pipetting. The microcentrifuge tube was quickly placed in a 5 mL round bottom flask and a rubber septum used to seal the tube, and argon was flushed into the flask for 5 minutes. The reaction was allowed to proceed for 2 hours. The modified DNA was then desalted twice through Centrisep desalting columns containing Sephadex G-50 superfine resin.
[0260] Note: Following the addition of sodium ascorbate, it is important to flush with argon as quickly as possible to minimize damage to the DNA.
Example 5
Strand Displacement
[0261] To the desalted reaction product, Thermopol buffer (1× final concentration), Aptamerfor primer (50 pmol), dNTPs (200 μM each final concentration), 8 U of Bst polymerase (large fragment) and H 2 O were added to a final volume of 50 μL. The reaction was incubated at 65° C. for 5 minutes followed immediately by buffer exchanging through a Centrisep column loaded with Sephadex G-50/binding buffer (20 mM Tris pH 7.5, 100 mM NaCl, 2 mM MgSO 4 ). Then, binding buffer plus 0.02% Tween-20 was added to a final volume of 50 μL and the solution was heated to 75° C. for 3 minutes and allowed to cool to room temperature.
[0262] Note: It is important to keep the mixture on ice prior to incubation at 65° C. to avoid unwanted side reactions. After strand displacement, it is important to quickly buffer exchange the reaction to remove dNTPs thus minimizing unwanted side reactions. At each desalting/buffer exchange step, the overall volume decreases. This is exacerbated by the inclusion of detergent (Triton X-100) in the polymerase buffer.
[0263] The state of the library at each stage of a SELMA cycle was monitored by acrylamide gel analysis ( FIG. 15 ). After polymerase extension in the presence of dATP, dCTP, dGTP and EdUTP, the alkyne-containing library had a duplex hairpin structure and ran (lane 2 and FIG. 14 b ) as a narrow, strongly-staining band with much less mobility than simple dsDNAs of similar length. Treatment of the library with Man 4 -azide under CuAAAC conditions resulted in a more diffuse band with a still higher apparent molecular weight (lane 3 and FIG. 14 c ). Primer 2 (see FIG. 14 a ) was then added, together with natural dNTP's and polymerase extension resulted in the strand-displaced library (lane 5 and FIG. 14 d ). Several observations and control experiments were consistent with the assumed ssDNA-dsDNA hybrid structure of the library at this stage. First, it ran as a smear in the gel and importantly, treatment with exonuclease I (which digests the 3′-terminal ssDNA portion) resulted in the appearance of a sharp 80-bp band corresponding to the dsDNA portion (lane 6). By contrast, the glycosylated double stranded hairpins showed no change upon exonuclease treatment (lanes 3 vs. 4). Heating the hybrid to 95° C. (but not 75° C.) destabilized the duplex portion of the hybrid structure, allowing the glycosylated strand to reinvade, expel the unglycosylated single strand and return to the duplex hairpin structure, which is impervious to the exonuclease (compare lanes 4, 7 and 8).
Example 6
Selection for 2G12 Antibody Affinity
[0264] 2G12 antibody was added to a final concentration of 50 nM and the solution was incubated at room temperature for 1 hr. Then, the mixture was added to 1.5 mg protein A Dynabeads and incubated for 45 minutes with rotation. The mixture was applied to a magnetic separator and the supernatant was removed by pipetting. Then, the mixture was washed with 100 μL, 150 μL, and 200 μL of binding buffer/0.02% Tween-20. Following washing, the beads were then resuspended in 30 μL elution buffer (20 mM Tris pH 8, 100 mM NaCl, 0.02% Tween-20) and placed in a boiling water bath for 2 minutes. The beads were immediately applied to a magnetic separator and the supernatant placed in a PCR tube.
Example 7
Amplification of Selected Mannose-DNA
[0265] Thermopol buffer (1× final conc.), 60 pmol aptamerfor-biotin and 60 pmol aptamerrev, dNTPs (200 μM final conc.), 4 U Vent(exo) polymerase and H 2 O were added to a final volume of 200 μL. The reaction was separated into 3 tubes and cycled at:
[0000] 1) 95° C. for 1.5 minutes,
2) 95° C. for 15 seconds,
3) 64° C. for 20 seconds,
4) 72° C. for 10 seconds,
5) Cycles 2 through 4 repeated for 12 cycles.
[0266] Note: Cycle number was empirically determined by removing the PCR tubes at varying cycle numbers (8-12) and running a portion (5 μL) of the reaction product on an agarose gel. Subsequently, all tubes are brought up to the optimal cycle number. It is important to avoid excessive cycling as this can lead to unwanted side reactions.
Example 8
Library Regeneration
[0267] 30 U Exonuclease I was added followed by incubation at 37° C. for 30 minutes and inactivation at 80° C. for 20 minutes to remove excess primer from the previous PCR reaction. 4 M NaCl was added to a final concentration of 500 mM and EDTA was added to a final concentration of 5 mM. The PCR product was then incubated with streptavidin magnetic beads for 30 minutes with intermittent mixing. The beads were washed twice with wash buffer (20 mM Tris pH 8.0, 500 mM NaCl) followed by the addition of 40 μL 100 mM NaOH for 4 minutes to elute the unbiotinylated strand. A magnetic rack was used to pellet the beads and the supernatant was immediately mixed with 40 μL of 1 M HCl and the solution was desalted through a Centrisep column loaded with Sephadex G-50.
[0268] Thermopol buffer (1× final concentration), library regeneration primer (40 pmol), dNTPs (200 μM each final concentration), 2 U of Vent polymerase and H 2 O were added to a final volume of 100 μL. The reaction was heated at 64° C. for 30 seconds followed by 2 minutes at 72° C. 30 U of Exonuclease I was added and the reaction was incubated at 37° C. for 30 minutes followed by 20 minutes at 80° C. 4 M NaCl was added to a final concentration of 500 mM and EDTA was added to a final concentration of 5 mM. The product was then incubated with streptavidin magnetic beads for 30 minutes with intermittent mixing. The beads were washed twice with wash buffer (20 mM Tris pH 8.0, 500 mM NaCl) followed by the addition of 40 μL 100 mM NaOH for 4 minutes to elute the unbiotinylated strand. A magnetic rack was used to pellet the beads and the supernatant was immediately mixed with 4 μL of 1 M HCl followed by 1 μL of 1 M Tris pH 8.
Example 9
Subsequent Rounds of Library Generation/Selection
[0269] 10 μL of the 45 μL recovered from the library regeneration step were used in each subsequent round of library generation/selection. 4 U of Bst polymerase was added instead of 8 U in both steps using this enzyme. 10 pmol aptamerfor was used for the strand displacement reaction. 50 nM antibody 2G12 were used in rounds 1 and 2, 10 nM antibody in rounds 3 and 4, and 5 nM antibody in rounds 5, 6, and 7. In rounds 2, 4, and 6, the library was counterselected against protein A magnetic beads by incubation with 0.75 mg beads for 30 minutes and using the supernatant to select for antibody 2G12 binding.
Example 10
Cloning of Selected Library
[0270] After 7 rounds of library generation/selection and amplification of the selected mannose-DNA from round 7, 2 μL of the amplification PCR product was used in a 100 μL amplification reaction using Vent(exo) polymerase according to the same parameters as used previously, except primer aptamerfor was used instead of primer aptamerfor-biotin. 5 U Taq polymerase was added to the PCR product and the reaction was incubated for 30 minutes at 72° C. to ensure optimal incorporation of overhanging adenosine nucleotides at the 3′ ends of both strands. A TOPO TA cloning kit was then used to clone the library according to manufacturer's instructions, using blue-white colony screening to identify positive clones. 20 white colonies were picked into LB broth and the plasmid isolated and sequenced.
Example 11
Preparation of Selected Clones for Filter Binding Assay
[0271] Clones were amplified using Vent(exo) polymerase in 100 μL reactions and 20 pmol each of primers hairpinfor and aptamerrev-biotin and the conditions/thermal cycling used previously for library amplification. In these reactions, deoxythymidine triphosphate was replaced by 5′ ethynyl-deoxyuridine triphosphate. The non-biotinylated strand was isolated using streptavidin magnetic beads as described, and 1 μL of 1 M Tris pH 8 was added to the isolated strand. 10 μL isolated single-stranded DNA was used in a 25 μL reaction containing 1× Thermopol buffer, 200 μM dNTPs, 15 pmol aptamerrev-biotin, and 0.5 U Vent polymerase. The reaction was incubated at 64° C. for 30 seconds followed by 72° C. for 2 minutes. Then, 10 U exonuclease I was added and the reaction was incubated at 37° C. for 30 minutes followed by inactivation at 80° C. for 20 minutes. The reaction was transferred to a cap-less 0.5 mL microcentrifuge tube. Added to the reaction was 2.5 μL 10 mM THPTA ligand, 1 μL 25 mM CuSO 4 , 2.5 μL of 35 mM mannose sugar-azide, and the reaction was mixed by pipetting. Then, 1 μL of fresh 250 mM sodium ascorbate was added followed by immediate mixing by pipetting. The microcentrifuge tube was quickly placed in a 5 mL round bottom flask and a rubber septum used to seal the tube, and argon was flushed into the flask for 5 minutes. The reaction was allowed to proceed for 2 hours. Then, 25 μL H 2 O was added and the reaction was immediately desalted twice through Centrisep desalting columns containing Sephadex G-50 superfine resin. The desalted modified DNA was then radioactively phosphorylated using polynucleotide kinase and ATP (γ- 32 P) according to manufacturer's instructions. The non-biotinylated, radiolabeled strand was then isolated using streptavidin magnetic beads as described, however four washes were performed to extensively remove unincorporated 32 P. 1 μL of 1 M Tris pH 8 was added and the resulting modified, labeled DNA was stored on ice or at 4° C.
Example 12
Filter Binding
[0272] 2.5 μL of modified, radiolabeled DNA was added to 50 μL binding buffer/0.02% Tween-20. The solution was heated to 75° C. for 3 minutes and allowed to cool to room temperature. Then, the desired amount of antibody 2G12 was added to the solution and binding allowed for 3 hours at room temperature. The solution was then filtered through a nitrocellulose/PVDF sandwich and the radioactivity in each membrane quantified by exposure to a phosphor screen followed by phosphor imaging.
[0273] Note: Nitrocellulose was exposed to 0.4 M NaOH for 10 minutes, washed extensively with H 2 O, and then soaked in binding buffer prior to the filter binding assay. PVDF was soaked in methanol prior to extensive washing with H 2 O and soaking in binding buffer prior to the filter binding assay.
Example 13
Binding
[0274] The results after 7 iterative rounds of selection/amplification are shown in FIG. 6 . The data show that the process enriched the pool of glyco-DNAs in the library that bound to 2G12. The best binders in the library were then cloned and sequenced, and were found to show binding at the ˜200-300 nM level.
Prophetic Example 14
Partial-Sequence Investigations
[0275] The minimal portion of the glyco-DNA clones' sequences necessary for binding to 2G12 will be determined. This will be accomplished through synthesis and binding evaluation of partial-sequence fragments.
Prophetic Example 15
Scale-Up
[0276] Several milligrams of glyco-DNA will be synthesized. This amount should be sufficient for immunogenicity studies as both unmodified glyco-DNA and phosphorothio-glyco-DNA.
Prophetic Example 16
Immunogenicity Studies
[0277] A small rabbit immunogenicity study will be conducted.
[0278] Rabbit sera will be monitored for binding to 1) individual Man 4 carbohydrates, 2) the glyco-DNA immunogens, and 3) HIV gp120, as well as HIV neutralization activity.
[0279] If antibodies that bind the carbohydrates or gp120 are elicited, characterization of the antibody response and/or further immunogenicity studies of the antigens in non-human primates will follow.
Example 17
Preparation of Mutant Clones from (−)-Strand Synthetic Oligos
[0280] All synthetic mutant clones were truncated to remove the loop portion of the sequence (24 italicized residues in clone sequences in FIG. 12 ).
[0281] In a PCR tube, 40 pmol of (−)-strand synthetic oligo complementary to a sequence in FIG. 17 , 2.5 μL 10× Thermopol buffer (New England Biolabs), 15 μL autoclaved H 2 O, and 2 μL 25 μM primer were combined. To this was added 0.5 μL of a solution containing 10 mM deoxyadenosine triphosphate, 10 mM deoxycytosine triphosphate, 10 mM deoxyguanosine triphosphate, and 10 mM alkyne-containing thymidine triphosphate analogue 5-ethynyl-deoxyuridine (EdU) triphosphate to afford a final concentration of 200 μM each. 8 U of Bst polymerase (large fragment) was added and the mixture was incubated at 60° C. for 2 minutes to complete synthesis of the duplex. The reaction was diluted with 25 μL of autoclaved H 2 O to a final volume of 50 μL.
[0282] For entry 21 of FIG. 17 , a synthetic (+)-sense strand containing the desired sequence was simply annealed to the (−)-sense strand to produce a similar duplex structure.
[0283] The reaction was transferred into a 0.5 mL microcentrifuge tube containing 5.0 μL 10 mM THPTA ligand and 2.0 μL 25 mM CuSO 4 . 5.0 μL of 35 mM mannose sugar-azide was added and the reaction was mixed by pipetting. Then, 2 μL of fresh 250 mM sodium ascorbate was added followed by immediate mixing by pipetting. The microcentrifuge tube was quickly placed in a 5 ml round bottom flask and a rubber septum used to seal the tube, and argon was flushed into the flask for 5 minutes. The reaction was allowed to proceed for 2 hours under argon. The modified DNA was then desalted twice through Centrisep desalting columns containing Sephadex G-50 superfine resin.
[0284] 24.5 μl of the desalted modified DNA was added to a PCR tube containing 1 uL 100 mM freshly prepared dithiothreitol (DTT) and 3.0 μL T4 Polynucleotide Kinase Reaction Buffer (10×). To the reaction was added 0.5-1.0 μL ATP (γ- 32 P-Perkin Elmer), followed by 10 U T4 Polynucleotide Kinase (New England Biolabs). The reaction was incubated at 37° C. for 2 hours and then the labeled product was incubated with streptavidin magnetic beads for 30 minutes at RT with rotation. The beads were washed four times with 150 μl wash buffer (20 mM Tris pH 8.0, 500 mM NaCl) followed by the addition of 40 μL 100 mM NaOH for 4 minutes to elute the unbiotinylated strand. The supernatant was immediately mixed with 4 μL of 1 M HCl followed by 1 μL of 1 M Tris pH 8.
[0285] These labeled ssDNA were then directly used in the labeling procedures as described in the filter binding section (Example 12).
Example 18
Measurement of Click Glycosylation Efficiency
[0286] The PAGE ( FIG. 21 a ) (20% acrylamide, 29:1 acrylamide:bis-acrylamide, EtBr staining) shows the progress of the click glycosylation of clone 6 at several timepoints over two hours. Roughly 10-11 bands can be seen in the gel (corresponding to starting oligo and one-through ten-fold-glycosylated species). The identity of the 3 major bands after 2 hrs was confirmed to be the 8, 9, and 10-clicked species by RP-HPLC/ESI-MS analysis ( FIG. 21 b ) (analysis by Novatia, Inc., 2×50 mm ACE C18 300 column, 60° C., 0.4 mL/min, 5-20% B over 19 min). See also FIG. 22 .
Example 19
Synthesis of 5-ethynyl-2′-deoxyuridine-5′-triphosphate (EdUTP)
[0287] General Methods.
[0288] All commercial reagents (Sigma-Aldrich, Alfa Aesar) were used as provided unless otherwise indicated. An anhydrous solvent dispensing system (J. C. Meyer) using 2 packed columns of neutral alumina was used for drying THF, Et 2 O, and CH 2 Cl 2 , while 2 packed columns of molecular sieves were used to dry DMF. Solvents were dispensed under argon. Analytical HPLC was performed on a Varian Microsorb column (C18, 5μ, 4.6×250 mm) with a flow rate of 0.5 mL/min while a Varian Dynamax column (C18, 8μ, 41.4×250 mm) with a flow rate of 40 mL/min was used for preparative HPLC. An isocratic or linear gradient of 0.1 M triethylammonium bicarbonate (TEAB) and aqueous MeCN (70%) were used. Teledyne ISCO CombiFlash Rf equipped with Teledyne ISCO RediSep Rf flash column silica cartridges (www.isco.com/combiflash) were used for flash chromatography with the indicated solvent system. Nuclear magnetic resonance spectra were recorded on a Varian 600 MHz with Me 4 Si, DDS or signals from residual solvent as the internal standard for 1 H and external H 3 PO 4 for 31 P. Chemical shifts are reported in ppm, and signals are described as s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet), brs (broad singlet), and dd (double doublet). Values given for coupling constants are first order. High resolution mass spectra were recorded on an Agilent TOF II TOF/MS instrument equipped with either an ESI or APCI interface. All reactions were performed under an inert atmosphere of dry Ar in oven dried (150° C.) glassware.
[0000]
5-Ethynyl-2′-deoxyuridine
[0289] 5-Iodo-2′-deoxyuridine (5, 1.0 g, 2.82 mmol) was dissolved in MeCN/Et 3 N (66 mL of 1:1, v/v) under argon atmosphere. Trimethylsilylacetylene (1.6 mL, 11.3 mmol), bis-(triphenylphosphine)-palladium(II) chloride (42.2 mg, 0.60 mmol), and CuI (28 mg, 0.15 mmol) were added, and the mixture was heated for 3.5 h in the flask immersed into a preheated oil bath (50° C.). The solvents were removed in vacuo to give a residue that was purified by silica gel flash column chromatography. Elution with CHCl 3 /MeOH (9:1, v/v) afforded trimethylsilyl intermediate as a solid (0.75 g, 82%). To the solution of this intermediate (0.7 g, 2.16 mmol) in anhydrous MeOH (16 mL) under argon atmosphere, a solution of NaOMe in MeOH (145 mL of 0.05 N) was added, and the reaction was stirred at 25° C. for 2 h. The pH of the solution was adjusted to 5-6 using Dowex 50 WX8-200 (H + ), the mixture was filtered, and concentrated in vacuo to give a residue that was purified by silica gel column flash chromatography using CHCl 3 /MeOH (8:2, v/v) as eluent to yield 5-ethynyl-2′-deoxyuridine (EdU) as a white solid (395 mg, 73%); 1 H NMR (DMSO-d 6 ) δ 11.62 (s, 1H, NH), 8.29 (s, 1H, H-6), 6.10 (dd, J=6.56, 6.56 Hz, 1H, H-1′), 5.24 (d, J=4.31 Hz, 1H, C-3′ OH), 5.12 (t, J=4.91 Hz, 1H, C-5′ OH), 4.23 (m, 1H, H-3′), 4.10 (s, 1H, CCH), 3.79 (q, J=3.25, 3.25, 3.26 Hz, 1H, H-4′), 3.59 (m, 2H, H-5′, H-5″), 2.16 (m, 2H, H-2′, H-2″). HRMS calcd for C 11 H 11 N 2 O 14 251.0673 (M−H) − . found 251.0683.
5-Ethynyl-2′-deoxyuridine-5′-triphosphate
[0290] EdU was dried by coevaporation with dry pyridine, and left over P 2 O 5 under vacuo overnight. The compound (75 mg, 0.3 mmol) was dissolved in solution of trimethylphosphate (2 mL), cooled in ice-bath, and a powdered Proton Sponge (96.4 mg, 0.45 mmol) was added followed by POCl 3 (30 μL, 0.33 mmol). After 2 h of stirring, a solution of tributylammonium pyrophosphate in DMF (3 mL, 1.5 mmol) containing tributylamine (300 μL, 1.26 mmol) was quickly added to the reaction mixture. After 2 min of stirring mixture was poured into 30 mL of 0.2 M TEAB, stirred and evaporated to dryness. Proton-Sponge was removed on small column with Dowex 50 WX8-200 (Na + ). The crude product was then purified by preparative HPLC with 70% MeCN/0.1M TEAB (2-10 linear gradient) to give a residue which was dissolved in water, and passed through a small column of Dowex 50 WX8-200 (Na + ). Fractions containing product were combined and lyophilized to give the product as a white powder (46.5 mg, 28%). 1 H NMR (D 2 O) δ 8.02 (s, 1H, H-6), 6.76 (t, J=6.59 Hz, 1H, H-1′), 4.44 (m, 1H, H-3′), 4.00 (m, 3H, H-4′, H-5′, H-5′), 3.39 (s, 1H, CCH), 2.12 (m, 2H, H-2′, H-2″). 31 P NMR (243 MHz, D 2 O) δ ppm −8.94 (d, J=20.38 Hz), −10.49 (d, J=20.19 Hz), −22.16 (t, J=20.17 Hz). HRMS calcd for C 11 H 14 N 2 O 14 P 3 490.9663 (M−H) − . found 490.9673.
INCORPORATION BY REFERENCE
[0291] All of the U.S. patents and U.S. published patent applications cited herein are hereby incorporated by reference.
EQUIVALENTS
[0292] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.
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Described herein are oligosaccharide-oligonucleotide conjugates useful as vaccines against one or more human or veterinary therapeutic indications, and methods of synthesizing and identifying them. The conjugates may be identified using non-human antibodies as binding targets, thereby expanding the power and scope of the invention. Efficacious conjugates may be identified through an iterative screening process.
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CONTRACTUAL ORIGIN OF THE INVENTION
The United States Government has rights in this invention pursuant to employer/employee agreement between the U.S. Department of Energy (DOE) and some of the inventors and through license agreements with the assignee of the invention.
BACKGROUND OF THE INVENTION
The present invention pertains to an integrated oxygen fueled combustion and pollution control system. More particularly, the present invention pertains to an oxy-fueled combustion system having integrated pollution control to effectively reduce, to near zero, emissions from combustion sources.
Oxy-fueled combustion systems are known in the art. Such systems use essentially pure oxygen for combustion with fuel in near stoichiometric proportions and at high flame temperatures for high efficiency energy production. Oxy-fuel systems are used in boilers to produce steam for electrical generation and in industrial settings, such as in aluminum recycling to melt aluminum for recasting. It is also contemplated that oxy-fueled combustion can be used for waste incineration as well as other industrial and environmental applications. Oxy-fuel technology and uses for this technology are disclosed in Gross, U.S. Pat. Nos. 6,436,337, 6,596,220, 6,797,228 and 6,818,176, all of which are commonly owned with the present application and are incorporated herein by reference.
Advantageously, because oxy-fuel combustion uses oxygen rather than air as an oxygen source, there is concomitant reduction in flue gas produced. In addition, combustion is carried out so that the NOx combustion products are near zero and are due almost exclusively to fuel-borne nitrogen. That is, because oxygen rather than air is used as an oxygen source, there is less mass flow and no nitrogen to contribute to the formation of NOx.
Although oxy-fuel combustion provides fuel efficient and reduced emission energy generation, there is still a fairly substantial amount of emissions that are produced during the combustion process. In addition, because the volume of gas is less, due to the use of oxygen instead of air, the concentration of other pollutants is higher. For example, the mass of SOx and particulate matter will not change, however, the concentration will increase because of the reduced overall volume.
Pollution control or removal systems are known in the art. These systems can, for example, use intimate contact between the flue gases and downstream process equipment such as precipitators and scrubbers to remove particulate matter, sulfur containing compounds and mercury containing compounds. Other systems use serial compression stripping of pollutants to remove pollutants and recover energy from the flue gas stream. Such a system is disclosed in Ochs, U.S. Pat. No. 6,898,936, incorporated herein by reference.
Accordingly, there is a need for a combustion system that produces low flue gas volume with integrated pollution removal. Desirably, such a system takes advantage of known combustion and pollution control systems to provide fuel efficient energy production in conjunction with reduced pollutant production and capture of the remaining pollutants that are produced.
BRIEF SUMMARY OF THE INVENTION
An integrated oxygen fueled combustion system and pollutant removal system, reduces flue gas volumes, eliminates NOx and capture condensable gases. The system includes a combustion system having a furnace with at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other. Combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases and is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds.
The pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid, preferably water, to produce a pollutant-laden liquid stream and a stripped flue gas stream. The system includes at least one compressor for receiving and compressing the stripped flue gas stream.
Preferably, the system includes a series of heat exchangers and compressors to cool and compress the flue gas. The flue gas can be cooled and compressed to and the stripped flue gas stream can separated into non-condensable gases and condensable gases. The condensable gases, in large part CO2, are condensed into a substantially liquid state and can be sequestered. The CO2 can be recirculated, in part, to carry a solid fuel such as coal into the furnace.
A method oxy-fuel combustion integrated with pollutant removal includes providing a furnace having at least one burner, and configured to substantially prevent the introduction of air, providing an oxygen supply for supplying oxygen at a predetermine purity greater than 21 percent and providing a carbon based fuel supply for supplying a carbon based fuel.
Either or both of the oxygen and carbon based fuel are limited to less than 5 percent over the stoichiometric proportion and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases and substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds.
The pollutant removal system is provided which includes a direct contact heat exchanger in serial arrangement with a compressor. The flue gas is brought into intimated contact with a cooling liquid, preferably water, in the heat exchanger to produce a pollutant-laden liquid stream and a stripped flue gas stream. The stripped flue gas stream is fed into the compressor to compress the stripped flue gas stream.
In a preferred method, the steps of cooling the stripped flue gas stream and compressing the cooled stripped flue gas stream are carried out as well as sequestering the compressed cooled stripped flue gas stream.
These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:
FIG. 1 is flow diagram of an integrated oxy-fuel combustion and pollutant removal system that was assembled for testing the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated. It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.
As discussed in the aforementioned patents to Gross, an oxy-fuel combustion system uses essentially pure oxygen, in combination with a fuel source to produce heat, by flame production (i.e., combustion), in an efficient, environmentally non-adverse manner. Oxygen, which is supplied by an oxidizing agent, in concentrations of about 85 percent to about 99+ percent can be used, however, it is preferable to have oxygen concentration (i.e., oxygen supply purity) as high as possible.
In such a system, high-purity oxygen is fed, along with the fuel source in stoichiometric proportions, into a burner in a furnace. The oxygen and fuel is ignited to release the energy stored in the fuel. For purposes of the present disclosure, reference to furnace is to be broadly interpreted to include any industrial or commercial heat generator that combusts fossil (carbon-based) fuel. For example, water-tube-walled boilers for electrical power generation, as well as direct fired furnaces for industrial applications are contemplated to use the oxy-fueled combustion system. In a preferred system, oxygen concentration or purity is as high as practicable to reduce green-house gas production.
It is contemplated that essentially any fuel source can be used. For example, oxygen can be fed along with natural gas, for combustion in a furnace. Other fuel sources contemplated include oils including refined as well as waste oils, wood, coal, coal dust, refuse (garbage waste), animal wastes and products and the like. Those skilled in the art will recognize the myriad fuel sources that can be used with the present oxy-fuel system.
Compared to conventional combustion processes which use air as an oxidizing agent to supply oxygen, rather than essentially pure oxygen, for combustion, the oxy-fuel system has an overall flow throughput that is greatly reduced. The oxygen component of air (about 21 percent) is used in combustion, while the remaining components (essentially nitrogen) are heated in and exhausted from the furnace. Moreover, the present process uses oxygen in a stoichiometric proportion to the fuel. That is, only enough oxygen is fed in proportion to the fuel to assure complete combustion of the fuel. Thus, no “excess” oxygen is fed into the combustion system.
Many advantages and benefits are achieved using the oxy-fuel combustion system. Aside from increased efficiency (or conversely reduced fuel consumption to produce an equivalent amount of power), because of the reduced input of gas, there is a dramatic decrease in the volume of flue gas. Based on the difference between using air which is 21 percent oxygen and pure oxygen, the volumetric flow rate is about one-fifth (⅕) using an oxy-fuel combustion system, compared to a conventional air-fed combustion system. In addition, because there is no energy absorbed by non-combustion related materials (e.g., excess oxygen or nitrogen), more energy is available for the underlying process.
Advantageously, the reduced gas volume (and thus flue gas volume) also increases the residence time of the gases in the furnace or boiler to provide additional opportunity for heat transfer.
In that the overall flue gas volume is so greatly reduced, highly efficient downstream processing that would otherwise not be available or would be impractical can now be used in large scale industrial and power generation settings.
Accordingly, the present invention uses oxy-fuel combustion in conjunction with the removal of multiple pollutants through the integrated condensation of H2O and CO2 with entrainment of particulates and dissolution and condensation of other pollutants including SO2. Such a pollutant removal system and method is disclosed in the aforementioned patent to Ochs et al.
Consolidating the removal of pollutants into one process has the potential to reduce costs and reduce power requirements for operation of such a system. Non-condensable combustion products including oxygen and argon may be present in combustion products. Although the oxy-fuel combustion system is operated at or very near stoichiometry (preferably within 5 percent of stoichiometry), oxygen may be present in the flue gas. Argon can come from the air separation process (remaining in the produced oxygen). Some relatively small amounts of nitrogen may also be present as fuel-borne or as air in-leakage into the underlying process equipment.
Condensable vapors such as H2O, CO2, SOx, and although minimal, NOx, are produced in the combustion process and are the targets for condensation. When referring to combustion products in this invention it is assumed that these condensable vapors and non-condensable gases are present as well as particulates and other pollutants.
The pollutant control portion of the system can also accomplish remediation and recovery of energy from combustion products from a fossil fuel power plant having a fossil fuel combustion chamber (e.g., a boiler, furnace, combustion turbine or the like), a compressor, a turbine, a heat exchanger, and a source of oxygen (which could be an air separation unit). Those skilled in the art will understand and appreciate that reference to, for example, a compressor, includes more than one compressor.
The fossil fuel power plant combustion products can include non-condensable gases such as oxygen and argon; condensable vapors such as water vapor and acid gases such as SOX and (again, although minimal, NOX); and CO2 and pollutants such as particulates and mercury. The process of pollutant removal and sequestration, includes changing the temperature and/or pressure of the combustion products by cooling and/or compressing the combustion products to a temperature/pressure combination below the dew point of some or all of the condensable vapors.
This process is carried out to condense liquid having some acid gases dissolved and/or entrained therein and/or directly condensing the acid gases (such as CO2 and SO2) from the combustion products. It is carried out further to dissolve some of the pollutants thus recovering the combustion products. Dissolve in the context of this disclosure means to entrain and/or dissolve.
This process is repeated through one or more of cooling and/or compressing steps with condensation and separation of condensable vapors and acid gases. The recovery of heat in the form of either latent and/or sensible heat can also be accomplished. The condensation reduces the energy required for continued compression by reducing mass and temperature, until the partially remediated flue gas is CO 2 , SO 2 , and H 2 O poor. Thereafter the remaining flue gases are sent to an exhaust.
The fossil fuel can be any of those discussed above. In certain instances, the pollutants will include fine particulate matter and/or heavy metals such as mercury other metals such as vanadium.
The present invention also relates to a method of applying energy saving techniques, during flue gas recirculation and pollutant removal, such that power generation systems can improve substantially in efficiency. For example, in the case of a subcritical pulverized coal (PC) system without energy recovery, the performance can drop from 38.3% thermal efficiency (for a modern system without CO2 removal) to as low as 20.0% (for the system with CO2 removal and no energy recovery). A system according to one embodiment of the present invention can perform at 29.6% (with CO2 removal) when energy recovery is included in the model design. it is anticipated that better efficiencies will be achieved. The present oxy-fuel combustion with integrated pollution control is applicable to new construction, repowering, and retrofits.
In an exemplary system using the present oxy-fuel and IPR process, flue gases as described in the table below are predicted. The flue gases will exit from the combustion region or furnace area, where they would pass through a cyclone/bag house or electrostatic precipitator for gross particulate removal. The combustion gas then passes through a direct contact heat exchanger (DCHX). In this unit the flue gases come into contact with a cooler liquid. This cooling step allows the vapors to condense. The step also allows for dissolving the entrained soluble pollutants and fine particles.
The gases exiting the first column are now cleaner and substantially pollutant free. These gases are compressed and can proceed into a successive DCHX and compression step. A final compression and heat exchange step is used to separate the oxygen, argon, and nitrogen (minimal) from the CO2. Also a mercury trap is used to remove gaseous mercury before release to atmosphere.
The table below shows the expected results as a comparison of the present oxy-fuel combustion and IPR system to a conventional air fueled combustion process. As the results show, the volume of flue gas at the outset, is less in the oxy-fuel combustion system by virtue of the elimination of nitrogen from the input stream. In the present system, the IPR serves to further reduce the volume and gas flow through successive compression and cooling stages. As the flue gases progress through the combined processes the final product is captured CO2 for sequestration.
TABLE 1
A COMPARISON OF THE PROPERTIES AND
COMPOSITIONS OF IPR-TREATED OXY-FUEL COMBUSTION
PRODUCTS WITH THOSE FROM A CONVENTIONAL COAL FIRED BOILER
Conventional
after
Oxyfuel
After 1 st
After 2 nd
After 3rd
economizer
exhaust
compression
compression
compression
Gas
1,716,395
686,985
364,367
354,854
353,630
Flow
(kg/hr)
Vol flow
1,932,442
826,995
72,623
15,944
661
(m 3 /hr)
Inlet
14.62
15.51
62
264
1,500
Pressure
(psia)
Inlet
270
800
342
323
88.2
Temp. (° F.)
Density
0.8882
0.8307
5.02
22.26
534.61
(kg/m 3 )
H 2 O
0.0832
0.33222
0.0695
0.00994
0.0004
(fraction)
Ar
0.0088
0.01152
0.0163
0.01730
0.0175
(fraction)
CO 2
0.1368
0.61309
0.8662
0.92161
0.9305
(fraction)
N 2
0.7342
0.00904
0.0128
0.01359
0.0137
(fraction)
O 2
0.0350
0.02499
0.0353
0.03755
0.0379
(fraction)
SO 2
0.0020
0.00913
0.0000
0.00000
0.0000
(fraction)
As can be seen from the data of Table 1, the volume of the combustion products has dropped significantly as a result of the successive compressing and cooling stages. The result is a capture of CO2 and subsequent sequestration, which is the ultimate goal. The CO2 thus resulting can be stored or used in, for example, a commercial or industrial application.
A test system 10 was constructed to determine the actual results vis-à-vis oxy-fuel combustion in conjunction with CO2 sequestration and pollutant removal. A schematic of the test system is illustrated in FIG. 1 . The system 10 includes an oxy-fueled combustor 12 having a coal feed 14 (with CO2 as the carrier gas 16 ), and an oxygen feed 18 . Coal was fed at a rate of 27 lbs per hour (pph), carried by CO2 at a rate of 40 pph, and oxygen at a rate of 52 pph. In that the system 10 was a test system rather than a commercial or industrial system (for example, a commercial boiler for electrical generation), the combustor 12 was cooled with cooling water to serve as an energy/heat sink.
The combustor exhaust 20 flowed to a cyclone/bag house 22 at which ash (as at 24 ) was removed at a rate of about 1 pph. Following ash removal 24 , about 118 pph of combustion gases remained in the flue gas stream 26 at an exit temperature that was less than about 300° F.
The remaining flue gases 26 were then fed to a direct contact heat exchanger 28 (the first heat exchanger). Water (indicated at 30 ) was sprayed directly into the hot flue gas stream 26 . The cooling water condensed some of the hot water vapor and further removed the soluble pollutants and entrained particulate matter (see discharge at 32 ). About 13 pph of water vapor was condensed in the first heat exchanger 28 —the flue gases that remained 34 were present at a rate of about 105 pph.
Following exit from the first heat exchanger 28 , the remaining gases 34 were fed into a first, a low pressure compressor 36 , (at an inlet pressure of about atmospheric) and exited the compressor 36 at a pressure of about 175 lbs per square inch gauge (psig). As a result of the compression stage, the temperature of the gases 38 increased. The remaining flue gases were then fed into a second direct contact heat exchanger 40 where they were brought into intimate contact with a cooling water stream as at 42 . The exiting stream 44 released about an additional 4 pph of water and thus had an exiting exhaust/flue gas 44 flow rate of about 101 pph.
Following the second heat exchanger 40 , the gases 44 were further compressed to about 250 psig at a second compressor 46 . Although the second compression stage resulted in a temperature increase, it was determined during testing that a third heat exchange step was not necessary. It will be appreciated that in larger scale operation, however, such additional heat exchange/cooling stages may be necessary.
A third compression stage, at a third compressor 48 was then carried out on the remaining flue gases 50 to increase the pressure of the exiting gas stream 52 to about 680 psig. Again, it was determined that although the temperature of the gases increased, active or direct cooling was not necessary in that losses to ambient through the piping system carrying the gases were sufficient to reduce the temperature of the gases.
A final compression, at a final compressor 52 , of the gases was carried out to increase the pressure of the gases to about 2000 psig. Following the final compression stage, the remaining gases 56 were fed into a heat exchanger 58 , the final heat exchanger, in which the temperature of the stream 56 was reduced to below the dew point of the of the gases and as a result, condensation of the gases commenced. The condensate (as at 60 ), which was principally liquefied CO2 (at a rate of 80 pph), was extracted and sequestered. In the present case, the CO2 was bottled, and retained.
The non-condensable gases (as at 62 ), which included a small amount of CO2, were passed through a mercury filter 64 and subsequently bled into an accumulator 66 . The accumulator 66 provided flexibility in control of the system flow rate. The exhaust 68 from the accumulator 66 was discharged to the atmosphere. The flow rate from the accumulator 66 , normalized to steady state from the overall system, was about 21 pph.
It will be appreciated by those skilled in the art that the above-presented exemplary system 10 was for testing and verification purposes and that the number and position of the compression and cooling stages can and likely will be changed to accommodate a particular desired design and/or result. In addition, various chemical injection points 70 , filters 72 , bypasses 74 and the like may also be incorporated into the system 10 and, accordingly, all such changes are within the scope and spirit of the present invention.
The projected fuel savings and other increased efficiencies of the present oxy-fuel combustion system with IPR are such that the cost of this combined process is anticipated to be competitive with current combustion technologies. Additionally, the prospect of new regulatory requirements are causing power plant designers to revisit the conventional approaches used to remove pollutants which would only serve to improve the economics behind this approach.
It will be appreciated that the use of oxy-fueled combustion systems with IPR in many industrial and power generating applications can provide reduced fuel consumption with equivalent power output or heat generation. Reduced fuel consumption, along with efficient use of the fuel (i.e., efficient combustion) and integrated IPR provides significant reductions in overall operating costs, and reduced and sequestered emissions of other exhaust/flue gases.
Due to the variety of industrial fuels that can be used, such as coal, natural gas, various oils (heating and waste oil), wood and other recycled wastes, along with the various methods, current and proposed, to generate oxygen, those skilled in the art will recognize the enormous potential, vis-à-vis commercial and industrial applicability, of the present combustion system. Fuel selection can be made based upon availability, economic factors and environmental concerns. Thus, no one fuel is specified; rather a myriad, and in fact, all carbon based fuels are compatible with the present system. Accordingly, the particulate removal stages of the integrated IPR system may vary.
As to the supply of oxygen for the oxy-fueled burners (combustion system), there are many acceptable technologies for producing oxygen at high purity levels, such as cryogenics, membrane systems, absorption units, hydrolysis and the like. All such fuel uses and oxygen supplies are within the scope of the present invention.
In general, the use of oxygen fuel fired combustion over current or traditional air fuel systems offers significant advantages in many areas. First is the ability to run at precise stoichiometric levels without the hindrance of nitrogen in the combustion envelope. This allows for greater efficiency of the fuel usage, while greatly reducing the NOx levels in the burn application. Significantly, less fuel is required to achieve the same levels of energy output, which in turn, reduces the overall operating costs. In using less fuel to render the same power output, a natural reduction in emissions results. Fuel savings and less emissions are but only two of the benefits provided by the present system. In conjunction with the integrated pollutant removal (IPR) system, the present oxy-fuel IPR system provides far greater levels of efficiency and pollution control than known systems.
It is anticipated that combustors (e.g., boilers) will be designed around oxygen fueled combustion systems with integrated IPR to take full advantage of the benefits of these systems. It is also anticipated that retrofits or modifications to existing equipment will also provide many of these benefits both to the operator (e.g., utility) and to the environment.
In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.
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An oxygen fueled integrated pollutant removal and combustion system includes a combustion system and an integrated pollutant removal system. The combustion system includes a furnace having at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases. The flue gas stream is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds. The integrated pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid to produce a pollutant-laden liquid stream and a stripped flue gas stream and at least one compressor for receiving and compressing the stripped flue gas stream.
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BACKGROUND OF THE INVENTION
The United States government has rights in this invention as a result of a grant from the NIAID of the National Institute of Health, Bethesda, Md.
This is a continuation of copending application Ser. No. 07/515,869 filed on Apr. 27, 1990 now abandoned.
The present invention is in the general area of organic chemistry, and specifically relates to new 4-[(alkyl or dialkyl)amino]quinoline derivatives which bind nucleic acid and their method of preparation.
A number of quinolines are used pharmaceutically as antimalarial, antiamoebic, and anesthetic drugs. The structures and numbering schemes for quinoline, (compound 1a) and its related compound, acridine (compound 1b) are provided below. ##STR1## Several aminoquinolines are known that interact with DNA. For example, Hahn, et al., have discovered that chloroquine (7-chloro-4-(4-diethylamino-1-methylbutylamino)quinoline)) and quinacrine (6-chloro-9-[[4-(diethylamino)-1-methylbutyl]amino]-2-methoxyacridine) have antimalarial and antiamoebic activity. F.E. Hahn et al. in Mil. Med. 131, 1071 (1966) determined that chloroquine inhibits nucleic acid biosynthesis by forming a molecular complex with DNA. Unfortunately, infants and children are extremely susceptible to adverse effects from high dosages of chloroquine. Sudden deaths have been reported on administration of the compound.
W. A. Denny, et al., in Anti-Cancer Druo Des. 2, 263 (1987) investigated the ability of certain quinolines to bind to DNA in a minimal fashion that would be suitable for the treatment of solid tumors remotely located from the site of administration of the drug. They found that 2-phenylquinolines are not active in vivo, and that 2-styrylquinolines bind to DNA too tightly to be used in the treatment of the remote solid tumors.
Cancer is now the second leading cause of death in the United States, Europe, and Japan, resulting in approximately 1,000,000 deaths annually in these countries. In the United States alone, each year over one million people are diagnosed with cancer, and over 500,000 people die from the disease. The number of newly diagnosed cancerous growths in patients in the United States is growing at a rate of 3% a year.
Chemotherapy now represents less than 4% of the total expenditures on the treatment of cancer. Chemotherapy involves the disruption of cell replication or cell metabolism. There are four major classes of chemotherapeutic agents currently in use for the treatment of cancer; anthracyclines, alkylating agents, antiproliferatives, and hormonal agents.
Viral diseases (including acquired immonodeficiency syndrome, or AIDS, caused by human immunodeficiency virus), as well as cancer, involve an undesirable proliferation of nucleic acids within a dysfunctional cell. AIDS was recognized as early as 1979. AIDS is generally accepted at this time to be a consequence of infection with the retrovirus, human immunodeficiency virus (HIV-1). Antibodies to these viruses are present in over 80% of patients diagnosed as having AIDS or pre-AIDS syndrome, and have been found with high frequency in identified risk groups.
A patient is generally diagnosed as having AIDS when a previously healthy person with an intact immune system acquires impaired T-cell immunity. The impaired immunity usually appears over a period of eighteen months to three years following infection. As a result of this impaired immunity, the patient becomes susceptible to opportunistic infections, various types of cancer such as Kaposi's sarcoma, and other disorders associated with reduced functioning of the immune system.
A number of compounds have been found to inhibit HIV activity or replication, including HPA-23, interferons, ribavirin, phosphonoformate, ansamycin, suramin, imuthiol, penicillamine, rifabutin, AL-721, 3'-azido-3'-deoxythymidine (AZT), and other 2',3'-dideoxynucleosides, such as 2',3'-dideoxycytidine (DDC), 2',3'-dideoxyadenosine (DDA), 3'-azido-2',3'-dideoxyuridine (AzddU), 2',3'-didehydrocytidine, 3'-deoxy-2',3'-didehydrothymidine and 3'-azido-5-ethyl-2',3'-dideoxyuridine (AzddEU).
It would be of great pharmaceutical benefit to provide new quinoline derivatives that effectively bind to DNA or RNA in a way that effectively reduces or inhibits unwanted nucleic acid replication, either alone or in combination with another pharmaceutical compound.
Several synthetic routes to quinoline derivatives containing an unsubstituted NH 2 group at position 4 are known. J. Bielavsky, Coll. Czech. Chem. Commun. 42, 2802 (1977); L. Strekowski et al., Heterocycles 29, 539 (1989); L. Strekowski et al., Tetrahedron Lett. 30, 5197 (1989); J.A. Moore and L.D. Kornreich, Tetrahedron Lett. 20, 1277 (1963); H. John, Ber. 59, 1447 (1926). However, these methods are not suitable for the preparation of quinolines with alkylamino (RNH) or dialkylamino (R 2 N) groups at position 4 of the quinoline.
The 4-alkylamino and 4-dialkylaminoquinolines have traditionally been synthesized by amination of 4-halogenoquinolines that have been prepared from 4-hydroxyquinolines. For a review of this method, see: R.K. Smalley, in "Quinolines," Part I, G. Jones, ed., Wiley, London, 1977, p. 319). As an example, 4-hydroxy-2-phenylquinoline, obtained in the condensation reaction between ethyl anthranilate and acetophenone diethyl ketal (R.C. Fuson and D.M. Burness, J. Am. Chem. Soc. 68, 1270 (1946)) Was treated with a mixture of PCl 5 and POCl 3 to give 4-chloro-2-phenylquinoline (L. Knorr and E. Fertig, Ber. 30, 937 (1897)). The latter compound was also prepared from 4-amino-2-phenylquinoline (H. John, J. Prakt. Chem. 226, 303 (1928)). Treatment of the chloroquinoline with diisoamylamine at high temperature gave 4-diisoamylamino-2-phenylquinoline in a low yield (H. John, J. Prakt. Chem. 226, 303 (1928)). U.S. Pat. No. 4,560,692 describes a similar reaction scheme that can be used to prepare several derivatives of 2-(4-X-phenyl)-4-piperidinoquinolines, where X=H, halogen, or alkyl.
This method of synthesis of 4-alkylamino and 4-dialkylaminoquinolines is difficult because it involves a number of steps and requires the use a toxic reagent (PCl 5 or POCl 3 ). It would be much more preferable to have a method of synthesis of these compounds that is more efficient and that utilizes less noxious reagents.
It is therefore an object of the present invention to provide an efficient and convenient process for the preparation of 4-[(alkyl or dialkyl)amino]quinolines.
It is another object of the present invention to provide new quinoline derivatives that can reduce or inhibit replication of nucleic acids.
It is another object of the present invention to provide new quinoline derivatives that can amplify the activity of known anticancer drugs.
SUMMARY OF THE INVENTION
The present invention is a method of synthesis of 4-[(alkyl and dialkyl)amino]quinolines of the formulas: ##STR2## wherein: R 1 is H, 2-chloro, 3-chloro, 4-chloro, 5-chloro, 3-methoxy, 4-methoxy, 5-methoxy, or 4-methylthio (numbering scheme based on parent aniline, wherein NH 2 is number 1 in the ring); R 2 is an alkylamino or dialkylamino group optionally substituted with aprotic substituents; R 3 is an alkenyl, aromatic, or heteroaromatic group optionally substituted with aprotic groups; n is 2 or 3; and X and Y are S, O, HC═CH, N═CH, or CH═N.
The new synthetic route to the derivatized quinolines described herein is a significant improvement over the prior art method of preparing 4-[(alkyl or dialkyl)amino]quinolines, because it includes fewer steps and is more efficient and cost effective.
The method includes condensing a 2-(trifluoromethyl)aniline or its derivative with an alkyl vinyl ketone, an alkyl aryl ketone, an alkyl heteroaryl ketone, or a cyclic ketone, to give the corresponding ketimine. The intermediate ketimines have not previously been described in the literature.
The ketimine is then anionically cyclized in the presence of a lithium alkylamide or a lithium dialkylamide to form a derivatized 4-[(alkyl or dialkyl)amino]quinoline. All of the fluorine atoms in the trifuoromethyl group of the ketimine are eliminated during the cyclization.
When prepared from an alkyl vinyl ketone, an alkyl aryl ketone, or an alkyl heteroaryl ketone, the resulting quinoline (structure I) contains an alkenyl, aromatic, or heteroaromatic substituent at position 2 of the quinoline and an alkylamino or dialkylamino (depending on the lithium reagent used) at position 4 of the quinoline. When prepared from a cyclic ketone, a dihydroacridine derivative or a H-indenoquinoline is formed (structures II and III) that has an aromatic ring fused to the saturated ring of the acridine or the H-indenoquinoline, and an alkylamino or dialkylamino group (depending on the lithium reagent used) at position 4 of the quinoline.
A number of the substituted quinolines of structure I prepared according to the method of synthesis described here have not previously been reported, including those wherein R 3 is 2,2-dialkylvinyl, biphenyl-4-yl, 2-naphthyl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl, 2-furanyl, or 2-thienyl optionally substituted with aprotic groups. In addition, dihydroccridines and Hindenoquinolines of structures II and III are likewise new. These new compounds are useful as intercalators of DNA and are capable of amplifying the effect of phleomycin and bleomycin, two anticancer agents. These compounds also exhibit selective in vitro inhibition of retroviruses, including HIV-1, the etiological agent of acquired immunodeficiency syndrome (AIDS).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of examples of new 4-[(alkyl or dialkylamino)]quinolines that can be prepared according to the method of synthesis of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term aliphatic refers to alkyl, aralkyl, alkenyl, alkenylaryl, alkynyl, alkynylaryl, cycloalkyl, nonaromatic cycloalkenyl, and dienyl groups. The term aromatic refers to conjugated cyclic structures with 4n+2 electrons in the pi shell. The term heteroaromatic refers to any aromatic compounds that include a heteroatom in the ring. The term aprotic refers to aliphatic, aromatic, and heteroaromatic groups that do not contain active hydrogens, including alkyl, alkoxy, alkylthio, alkenyl, halogen, and dialkylamino groups. The term quinoline as referred to here includes fused quinolines including acridines.
In one embodiment, the present invention is a convenient two step process for the preparation of 4-[(alkyl and dialkyl)amino]quinolines of the formulas: ##STR3## wherein: R 1 is H, 2-chloro, 3-chloro, 4-chloro, 5-chloro, 3-methoxy, 4-methoxy, 5-methoxy, or 4-methylthio (numbering scheme based on parent aniline, wherein NH 2 is number 1 in the ring); R 2 is an alkylamino or dialkylamino group optionally substituted with aprotic substituents; R 3 is an alkenyl, aromatic, or heteroaromatic group optionally substituted with aprotic groups; n is 2 or 3; and X and Y are S, O, HC═CH, N═CH, or CH═N. For example, R 2 can be selected from the group consisting of alkylamino, dialkylamino, N, N-dialkylethylenediamino, N-alkylethylenediamino, 4-alkylpiperazino, piperazino, morpholino, thiomorpholino, 1,2,3,4-tetrahydroquinolin-1-yl, indolin-1-yl, 1,2,3,4-tetrahydroisoquinolin-2-yl, and piperidino.
In the first step of the process, illustrated in Schemes I, X, and XII, 2-(trifluoromethyl)aniline or its derivative is condensed with CH 3 C(O)R 3 , wherein R 3 is an alkenyl, aromatic, or heteroaromatic group (optionally substituted with aprotic groups), or cyclic ketones 13 or 16, to form intermediate ketimines 12, 14, or 17, respectively. Examples of ketones that can be used in this reaction scheme are described in Tables 1, 12, and 14. Examples of ketimines that can be prepared by this method are listed in Table 2, 12, and 14.
The compound 2-(trifluoromethyl)aniline (also referred to as 2-(trifluoromethyl)benzenamine, as well as 4-chloro-2-(trifluoromethyl)aniline, are commercially available from Aldrich Chemical Company. Methods for the preparation of 3-chloro-2-(trifluoromethyl)aniline, 5-chloro-2-(trifluoromethyl)aniline, and 2-chloro-6-(trifluoromethyl)aniline are known. See Wakselman, et al., European Patent No. 206951; U.S. Pat. No. 4,008,278 to Boudakin et al. 3-Methoxy-2-trifluoromethylaniline and 5-methoxy-2-(trifluoromethyl)aniline can be prepared according to the synthesis described by Wakselman, et al., J. Chem. Soc., Chem. Commun. 1701 (1987). 4-Methoxy-2-(trifluoromethyl)aniline can be prepared as described in DE 2788073 to Wolfrum, et al.. The preparation of 4-methythio-2-trifluoromethylaniline is described in DE 2815340 to Ruffing et al., and DE 2551027 to Fridinger, et al.
Noncyclic ketones 111-11l (See Table 1) are commercially available from Aldrich Chemical Company. The other ketonis listed in Table 1 can be prepared according to the following literature methods: 11m, Ohta, et al., Heterocvcles, 23(7), 1759 (1985); 11n-11s, Sakamoto, et al., Synthesis. 245 (1984); 11t, McNamara, et al., Tetrahedron, 40(22), 4685 (1984); 11u, Leardini, et al., J. Chem. Soc., Chem. Commun. 1390 (1985); 11v, Miura, et a)., J. Chem., Soc. PT1, 1021 (1987).
Cyclic ketones 13 and 16 are also commercially available (6,7-dihydrobenzo[b]thiophen-4(5H)-one, tetralone, and 1-indanone) or can be prepared according to published literature methods. See for example, Coujat, et al., Tetrahedron Letters 2885 (1975) (5,6-dihydrobenzo[b]thiophen-7(4H)-one); Thummel, et al., J. Ore. Chem. 49, 2208 (1984) (6,7-dihydro-8(5H)-quinolinone); Epsztajn, et al., J. Chem. Soc., PT1, 213 (1985) (7,8-dihydro-5(6H)-quinolinone and 7,8-dihydro-5(6H)isoquinolinone); and Walsh, et al., Tetrahedron Letters 27(10), 1127 (1986) (5,6-dihydro-7(4H)-benzo[b]furanone and 6,7-dihydro-4(5H)-benzo[b]furanone).
In the second step, as illustrated in Schemes II through IX, XI, and XIII, the intermediate ketimines 12, 14, and 17, are reacted with a lithium alkylamide or a lithium dialkylamide to form a 2-substituted-4-(alkylamino or dialkylamino)-6-(substituted)-quinoline, a 5,6-dihydrobenzo[c]acridine derivative, or a H-indenoquinoline. Examples of alkylamides and dialkylamides suitable for reaction with the ketimine are set out in Tables 3-10, 13 and 15 (defined in the Tables as R 2 ). In general, any primary or secondary alkylamine that is capable of forming a lithium salt that reacts with the intermediate ketimine is suitable for this process. The alkylamino and dialkylamino groups can be linear, branched, or cyclic and can optionally include heteroatoms (O, N, and S) in the alkyl chain. The alkylamino and dialkylamino groups can also contain aprotic substituents bonded to the alkyl portions of the molecules, including alkenyl and dialkylamino groups. Further, the dialkyl groups can be linked together covalently to form a cyclic structure such as that found in piperidine, morpholine, and thiomorpholine. In addition to being covalently linked, the dialkyl groups can be part of a tetrahydroheteroaromatic system, such as 1,2,3,4-tetrahydroquinoline, and 1,2,3,4-tetrahydroisoquinoline. Alternatively, the cyclic dialkyl structure can have a fused aromatic or heterocyclic ring attached as in indoline.
This method is suitable for the preparation of quinolines substituted at position 2 (R 3 ) with dialkylvinyl groups, such as compound 2 (see FIG. 1), with aryl groups, such as compounds 3 and 4, and with heteroaryl groups, such as 5-9. The heteroaryl group can be either unsubstituted, as in compounds 4-8 or substituted, as in compound 9. The R 3 substituents can be optionally substituted with aprotic groups. Examples of suitable R 3 groups are listed in Table 1, and include 2,2-dialkylvinyl, biphenyl-4-yl, 2-naphthyl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl, 2-furanyl, 2-thienyl, 5-methyl-2-thienyl, 2-thiazolyl, 3-thienyl, 2-benzo[b]furanyl, 2-benzothiazoly, 2-quinolinyl, 1-isoquinolinyl, 4-isoquinolinyl, 3-isoquinolinyl, 3-quinolinyl, 4-quinolinyl, 3-furanyl, 2-benzo[b]thienyl, and 3-benzo[b]thienyl groups. The IUPAC nomenclature, chemical formulas and melting points for quinoline derivatives 2 through 9, or their hydrobromide salts, are provided in Table 11.
The method is also suitable for the preparation of fused quinolines (also referred to as dihydroacridines and H-indenoquinolines) 15 and 18. The dihydroacridine is further derivatized With a fused benzo ring (15a, 15b, 5c, and 15d), thieno ring (15e, 18a), pyridine ring (15g, 5h, 18c, and used), or furanyl ring (15f, 18b). ##STR4##
TABLE 1______________________________________Starting Ketones 1111 R.sup.3______________________________________a 2-methyl-1-propenylb biphenyl-4-ylc 2-naphthyld 2-pyridinyle 3-pyridinylf 4-pyridinylg 2-furanylh 2-thienyli 5-methyl-2-thienylj 2-thiazolylk 3-thienyll 2-benzofuranylm 2-benzothiazolyln 2-quinolinylo 1-isoquinolinylp 4-isoquinolinylq 3-isoquinolinylr 3-quinolinyls 4-quinolinylt 3-furanylu benzo[b]theien-2-ylv benzo[b]thein-3-yl______________________________________
TABLE 2______________________________________Ketimines 1212 R.sup.1 R.sup.3 Yield (%) mp (°C.)______________________________________a H 2-methyl-1-propenyl 60 oilb Cl 2-methyl-1-propenyl 68 oilc H biphenyl-4-yl 83 137-138d Cl biphenyl-4-yl 81 160-163e H 2-naphthyl 71 87-89f Cl 2-naphthylg H 2-pyridinyl 80 oilh Cl 2-pyridinyl 82 oili H 3-pyridinyl 85 oilj Cl 3-pyridinyl 84 82-84k H 4-pyridinyl 84 72-74l Cl 4-pyridinyl 80 oilm H 2-furanyl 80 25-27n Cl 2-furanyl 74 oilo H 2-thienyl 82 67-69p Cl 2-thienyl 91 oilq H 5-methyl-2-thienyl 88 oilr Cl 5-methyl-2-thienyl 80 81-83______________________________________ ##STR5##
TABLE 3______________________________________Quinolines 22 R.sup.1 R.sup.2 Formula Yield (%)______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.17 H.sub.23 N.sub.3 73b Cl NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.17 H.sub.22 ClN.sub.3 79______________________________________ ##STR6##
TABLE 4______________________________________Quinolines 33 R.sup.1 R.sup.2 Formula Yield (%)______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.25 H.sub.25 N.sub.3 89b H C.sub.26 H.sub.25 N.sub.3 91______________________________________ ##STR7##
TABLE 5______________________________________Quinolines 44 R.sup.1 R.sup.2 Formula Yield (%)______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.23 H.sub.23 N.sub.3 95______________________________________ ##STR8##
TABLE 6______________________________________Quinolines 55 R.sup.1 R.sup.2 Formula Yield (%)______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.18 H.sub.20 N.sub.4 82b H C.sub.20 H.sub.24 N.sub.4 72c H N(CH.sub.2 CH.sub.3).sub.2 C.sub.18 H.sub.19 N.sub.3 48d H ##STR9## C.sub.19 H.sub.20 N.sub.4 74e H ##STR10## C.sub.23 H.sub.19 N.sub.3 62f H ##STR11## C.sub.18 H.sub.17 N.sub.3 O 15g H ##STR12## C.sub.18 H.sub.17 N.sub.3 S 15h H ##STR13## C.sub.22 H.sub.17 N.sub.3 63i Cl ##STR14## C.sub.19 H.sub.20 N.sub.4 32______________________________________ ##STR15##
TABLE 7______________________________________Quinolines 66 R.sup.1 R.sup.2 Formula Yield (%)______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.18 H.sub.20 N.sub.4 85b H C.sub.20 H.sub.24 N.sub.4 74c H N(CH.sub.2 CH.sub.3).sub.2 C.sub.18 H.sub.19 N.sub.3 71d H ##STR16## C.sub.19 H.sub.20 N.sub.4 74e H ##STR17## C.sub.23 H.sub.19 N.sub.3 54f H ##STR18## C.sub.23 H.sub.19 N.sub.3 51g H ##STR19## C.sub.22 H.sub.17 N.sub.3 82h H ##STR20## C.sub.18 H.sub.17 N.sub.3 O 35i H ##STR21## C.sub.18 N.sub.17 N.sub.3 S 65j H ##STR22## C.sub.20 H.sub.21 N.sub.3 45k H ##STR23## C.sub.20 H.sub.21 N.sub.3 60l H ##STR24## C.sub.20 H.sub.21 N.sub.3 70______________________________________ ##STR25##
TABLE 8______________________________________Quinolines 7a R.sup.1 R.sup.2 Formula Yield (%)______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.18 H.sub.20 N.sub.4 82b H C.sub.20 H.sub.24 N.sub.4 88c H ##STR26## C.sub.19 H.sub.20 N.sub.4 94d Cl NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.18 H.sub.19 ClN.sub.4 36______________________________________ ##STR27##
TABLE 9______________________________________Quinolines 88 R.sup.1 R.sup.2 Formula Yield (%)______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 C.sub.17 H.sub.19 N.sub.3 O 66b H N[CH(CH.sub.3).sub.2 ].sub.2 C.sub.19 H.sub.22 N.sub.2 O 78c H C.sub.18 H.sub.19 N.sub.3 O 21______________________________________ ##STR28##
TABLE 10__________________________________________________________________________Quinolines 99 R.sup.1 R.sup.2 R.sup.4 Formula Yield (%)__________________________________________________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 H C.sub.17 H.sub.19 N.sub.3 S 95b H NHC(CH.sub.3).sub.3 H C.sub.17 H.sub.18 N.sub.2 S 67c H H C.sub.19 H.sub.23 N.sub.3 S 95d H ##STR29## H C.sub.18 H.sub.19 N.sub.3 S 91e Cl NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 H C.sub.17 H.sub.18 ClN.sub.3 S 74f Cl ##STR30## H C.sub.18 H.sub.18 ClN.sub.3 S 84g H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 CH.sub.3 C.sub.18 H.sub.21 N.sub.3 S 82h Cl NHCH.sub.2 CH.sub. 2 N(CH.sub.3).sub.2 CH.sub.3 C.sub.18 H.sub.20 ClN.sub.3 S 48__________________________________________________________________________
TABLE 11______________________________________Names, formulas, and melting points for quinolines 2-9 or theirhydrobromide salts (obtained from non-crystalline quinolines 2-9).No Name Formula Mp (°C.)______________________________________2a N-[2-(diemthylamino) C.sub.17 H.sub.23 N.sub.3.2HBr.1/2H.sub.2 O 278-280 ethyl]-2-(2-methyl-1- propenyl)-4-quinolin- amine dihydrobromide2b 6-chloro-N-[2-(dimethyl- C.sub.17 H.sub.22 ClN.sub.3 90-92 amino)ethyl]-2-(2-methyl- 1-propenyl)-4-quinolin- amine3a 2-(biphenyl-4-yl)-N-[2- C.sub.25 H.sub.25 N.sub.3.H.sub.2 O 129-131 (dimethylamino)ethyl]-4- quinolinamine3b 2-(biphenyl-4-yl)-4-(4- C.sub.26 H.sub.25 N.sub.3.2HBr.1/2H.sub.2 O 179-181 methylpiperazino)quino- line dihydrobromide4a N-[2-(diemthylamino) C.sub.23 H.sub.23 N.sub.3.1/4H.sub.2 O 161-163 ethyl]-2-(2-naphthyl)-4- quinolinamine5a N-[2-(dimethylamino) C.sub.18 H.sub.20 N.sub.4.2HBr.3/2H.sub.2 O 279-282 ethyl]-2-(2-pyridinyl)-4- quinolinamine dihydro- bromide5b N-[2-(diemthylamino) C.sub.20 H.sub.24 N.sub.4.2HBr.2H.sub.2 O 228-230 ethyl]-N-ethyl-2-(2- pyridinyl)-4-quinolin- amine dihydrobromide5c N,N-diethyl-2-(2-pyridin- C.sub.18 H.sub.19 N.sub.3.HBr 210-212 yl)-4-quinolinamine hydrobromide5d 4-(4-methylpiperazino)- C.sub. 19 H.sub.20 N.sub.4.2HBr.H.sub.2 O 316-320 2-(2-pyridinyl)quinoline dihydrobromide5e 2-(2-pyridinyl)-4-(1,2,3,4- C.sub.23 H.sub.19 N.sub.3 161-162 tetrahydroquinolin-1-yl)- quinoline5f 4-morpholino-2-(2-pyridin- C.sub.18 H.sub.17 N.sub.3 O 116-117 yl)quinoline5g 2-(2-pyridinyl)-4-thio- C.sub.18 H.sub.17 N.sub.3 S 142-143 morpholinoquinoline5h 4-indolino-2-(2-pyridinyl) C.sub.22 H.sub.17 N.sub.3 139-140 quinoline5i 6-chloro-4-(4-methylpi- C.sub.19 H.sub.20 N.sub.4 162-164 perazino)-2-(2-pyridin- yl)quinoline6a N-[2-(dimethylamino) C.sub.18 H.sub.20 N.sub.43.3HBr 281-283 ethyl]-2-(3-pyridinyl)- 4-quinolinamine trihy- drobromide6b N-[2-(dimethylamino) C.sub.20 H.sub.24 N.sub.4.3HBr.3H.sub.2 O 131-133 ethyl]-N-ethyl-2-(3- pyridinyl)-4-quinolin- amine trihydrobromide6c N,N-diethyl-2-(3-pyridin- C.sub.18 H.sub.19 N.sub.3.HBr 230-232 yl)-4-quinolinamine hydrobromide6d 4-(4-methylpiperazino)- C.sub.19 H.sub.20 N.sub.4 127-128 2-(3-pyridinyl)quinoline6e 2-(3-pyridinyl)-4-(1,2,3,4- C.sub.23 H.sub.19 N.sub.3 163-164 tetrahydroquinolin-1-yl)- quinoline6f 2-(3-pyridinyl)-4-(1,2,3,4- C.sub.23 H.sub.19 N.sub.3 127-128 tetrahydroisoquinolin- 2-yl)-quinoline6g 4-(indolino)-2-(3-pyri- C.sub.22 H.sub.17 N.sub.3 148-150 dinyl)-quinoline6h 4-morpholino-2-(3-pyri- C.sub.18 H.sub.17 N.sub.3 O 131-133 dinyl)quinoline6i 2-(3-pyridinyl)-4-thio- C.sub.18 H.sub.17 N.sub.3 S 126-127 morpholinoquinoline6j 4-(2-methylpiperidino)-2- C.sub.20 H.sub.21 N.sub.3.HBr.1/2H.sub.2 O 235-238 (3-pyridinyl)quinoline hydrobromide6k 4-(3-methylpiperidino)-2- C.sub.20 H.sub.21 N.sub.3.HBr.1/2H.sub.2 O 218-222 (3-pyridinyl)quinoline hydrobromide6l 4-(4-methylpiperidino)-2- C.sub.20 H.sub.21 N.sub.3.HBr.1/2H.sub.2 O 244-246 (3-pyridinyl)quinoline hydrobromide7a N-[2-(dimethylamino) C.sub.18 H.sub.20 N.sub.4 110-112 ethyl]-2-(4-pyridinyl)-4- quinolinamine7b N-[2-(dimethylamino) C.sub.20 H.sub.24 N.sub.4 3HBr.H.sub.2 O 248-250 ethyl]-N-ethyl-2-(4- pyridinyl)-4-quinolin- amine trihydrobromide7c 4-(4-methylpiperazino)- C.sub.19 H.sub.20 N.sub.4.2HBr.3/2H.sub.2 O 226-229 2-(4-pyridinyl)quinoline dihydrobromide7d 6-chloro-N-[2-(di- C.sub.18 H.sub.19 ClN.sub.4 120-121 methylamino)ethyl]-2- (4-pyridinyl)-4-quinolin- amine8a N-[2-(dimethylamino) C.sub.17 H.sub.19 N.sub.3 O 93-95 ethyl]-2-(2-furanyl)- 4-quinolinamine8b N,N-diisopropyl-2-(2- C.sub.19 H.sub.22 N.sub.2 O.HBr 195-196 furanyl)-4-quinolinamine hydrobromide8c 2-(2-furanyl)-4-(4-meth- C.sub.18 H.sub.19 N.sub.3 O.2HBr.H.sub.2 O 335-340 ylpiperazino)quinoline dihydrobromide9a N-[2-(dimethylamino) C.sub.17 H.sub.19 N.sub.3 S 109-110 ethyl]-2-(2-thienyl)- 4-quinolinamine9b N-(tert-butyl)-2-(2-) C.sub.17 H.sub.18 N.sub.2 S 96-98 thienyl-4-quinolin- amine9c N-[2-(dimethylamino) C.sub.19 H.sub.23 N.sub.3 S.2HBr.2H.sub.2 O 263-264 ethyl]-N-ethyl-2-(2- thienyl)-4-quinolinamine dihydrobromide9d 4-(4-methylpiperazino)- C.sub.18 H.sub.19 N.sub.3.2HBr.2H.sub.2 O 330-334 2-(2-thienyl)quinoline di- hydrobromide9e 6-chloro-N-[2-(dimethyl- C.sub.17 H.sub.18 ClN.sub.3 S 150-151 amino)ethyl]-2-(2-thi- enyl)-4-quinolinamine9f 6-chloro-4-(4-methylpi- C.sub.18 H.sub.18 ClN.sub.3 S 120-122 perazino)-2-(2-thienyl) quinoline9g N-[2-(dimethylamino)- C.sub.18 H.sub.21 N.sub.3 S 103-105 ethyl]-2-(5-methyl-2-thi- enyl)-4-quinolinamine9h 6-chloro-N-[2-(dimethyl- C.sub.18 H.sub.20 ClN.sub.3 S 119-120 amino)ethyl]-2-(5-methyl- 2-thienyl)-4-quinolin- amine______________________________________ ##STR31##
TABLE 12______________________________________Ketimines 1414 R.sup.1 n X______________________________________a H 3 CHCHb H 2 CHCHc Cl 3 CHCHd H 3 Se Cl 3 Sf H 3 Og H 3 NCHh H 3 CHN______________________________________ ##STR32##
TABLE 13______________________________________Fused quinolines 1515 R.sup.1 R.sup.2 n X______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 3 CHCHb H 3 CHCHc Cl NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 3 CHCHd H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 2 CHCHe H ##STR33## 3 Sf H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 3 Og H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 3 NCHh H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 3 CHN______________________________________ ##STR34##
TABLE 14______________________________________Ketimines 1717 R.sup.1 Y______________________________________a H Sb H Oc H NCH______________________________________ ##STR35##
TABLE 15______________________________________Fused quinolines 1818 R.sup.1 R.sup.2 Y______________________________________a H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 Sb H Oc H NHCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2 NCH______________________________________
TABLE 16______________________________________Mediam effective concentrations (EC.sub.50) of quinolines againstHIV-1 as determined in human peripheral blood mononuclear(PBM) cells infected with HIV-1 (strain LAV). Quinoline EC.sub.50 (μM)______________________________________ 5a 1.1 5b 13.2 5d 5.5 6a 1.5 6b 24.2 6d 1.0 7c 68.2 8a 0.9 8c 1.0 8d 15.8 9a 1.0 9c 32.4______________________________________
The new 4-[(alkyl and dialkyl)amino]quinolines described herein are useful as agents that bind to DNA, and are capable of amplifying the effect of drugs that bind to DNA, for example, the known anticancer agents bleomycin and phleomycin. These compounds also exhibit selective in vitro inhibition of retroviruses, including HIV-1, the etiological agent of acquired immunodeficiency syndrome (AIDS).
In a third embodiment, the present invention provides new ketimines of the formulas: ##STR36## wherein: R 1 is H, 2-chloro, 3-chloro, 4-chloro, 5-chloro, 3-methoxy, 4-methoxy, 5-methoxy, or 4-methylthio; R 3 is an alkenyl, aromatic, or heteroaromatic group optionally substituted with aprotic groups; n is 2 or 3; and X and Y are HC═CH, N═CH, CH═N, O, or S.
These compounds are useful as intermediates in the preparation of the active 4-[(alkyl and dialkyl)amino]quinolines described herein.
This invention is further illustrated by the following nonlimiting examples describing the method of synthesis and use of these compounds.
I. Method of Preparation of 4-[(Alkyl and Dialkyl)amino]quinolines
The starting materials for the 4-[(alkyl and dialkyl)amino]quinolines are 2-(trifluoromethyl)anilines 10 and ketones 11, 13 and 16. (see Scheme I and Table 1). In the following discussion, for ease of illustration, the method is described with reference to the reaction of 2-(trifluoromethyl)aniline or 4-chloro-2-(trifluoromethyl)aniline with the noncyclic ketone followed by cyclization of the resulting ketimine to form the corresponding quinoline derivative. However, it should be understood that the present invention is not limited to this examples but includes all of the described combinations of starting materials and products.
In the first step, a mixture of 10 and 11 and a catalytic amount of an acid catalyst, such as p-TsOH (p-toluenesulfonic acid) in an aromatic hydrocarbon solvent such as benzene or toluene is heated under reflux with azeotropic removal of water. This condensation reaction is monitored by measuring the volume of water formed during the condensation. It is typically completed within three to fifteen hours. The time of reaction will vary depending on the reagents and solvent used. The crude ketimine is isolated by removal of the solvent by evaporation and is then purified by distillation under reduced pressure. The conditions of distillation will vary based on the structure of the ketimine. In general, the distillation is carried out at a temperature between 100°-150° C. and at a pressure of between 0.1-0.5 mm Hg. The ketimines 12 (Scheme I and Table 2) thus obtained are sufficiently pure to be used in the second synthetic step of the process.
A solution of a primary or secondary alkylamine in an ether solvent, such as diethyl ether or tetrahydrofuran, under anhydrous conditions, is treated with one molar equivalent of a solution of commercial lithium reagent, such as methyllithium or butyllithium. The solution or suspension of the lithium amide is then treated with a solution of ketimine 12, and the reaction mixture is stirred for 0.5-2 hours. The preferred molar ratio of the lithium amide to the ketimine is 4:1. The preferred reaction temperature is between -10° and +10° C. for lithium reagents derived from primary amines and between -20° and -10° C. for lithium reagents derived from secondary amines. The progress of the reaction is conveniently monitored by thin layer chromatography on silica gel. When the reaction is completed, it is quenched with water. The crude quinoline is purified on a short chromatography column packed with silica gel with a mixture of hexanes/triethylamine/ethanol (7:2:1) as an eluent. The final purification of solid quinolines includes crystallization from a hydrocarbon solvent such as hexanes. Non-crystalline quinolines are conveniently purified by treatment with an acid, preferably hydrobromic acid, and crystallization of the resultant salt from an alcohol, such as ethanol, or a mixture of ethanol with hexanes.
The structural formulas of quinoline derivatives obtained by this method are given in Schemes II-IX, XI, and XIII and the corresponding Tables 3-10, 13, and 15. As can be seen from Tables 3-10, the yields of isolated quinolines 2-9 are good to excellent with only a few exceptions. The IUPAC nomenclature for compounds 2-9 are given in Table 11.
The following non-limiting examples provide detailed procedures for the synthesis of ketimines such as 12q and substituted quinolines such as 9g.
N-[1-(5-Methyl-2-thienyl)ethylidene]-2-(trifluoromethyl)aniline (12q)
A solution of 2-(trifluoromethyl)aniline (4.0 q, 25 mmol), 2-acetyl-5-methylthiophene (4.4 g, 31 mmol), and p-toluenesulfonic acid (50 mg) in toluene (30 mL) was heated under reflux with azeotropic removal of water for 10 hours. Then the mixture was concentrated on a rotary evaporator, and the oily residue was distilled under reduced pressure to give 6.2 g (88%) of ketimine 12q as an oil (bp 128°-130° C./0.3 mm Hg).
Other ketimines 12 were prepared in a similar manner. Crystalline compounds 12 were additionally crystallized from hexanes.
N-[2-(dimethylamino)ethyl]-2-(5-methYl-2-thienyl)-4-quinolinamine (9g)
A solution of N,N-dimethylethylenediamine (0.66 ml, 6.0 mmol) in ether (15 mL) was treated with a commercial solution of n-butyllithium (6.0 mmol) in hexanes at -10° C., and the resultant mixture was stirred at -10° C. for 20 minutes before treatment with a solution of ketimine 12q (0.42 g, 1.5 mmol) in ether (5 mL). The mixture was stirred at -10° C. for an additional 45 minutes, and then quenched with water (0.5 mL). The organic layer was concentrated on a rotary evaporator to give a crystalline residue. Removal of colored polymeric materials on a short silica gel column by eluting quinoline 9g with hexanes/Et 3 N/EtOH (7:2:1) was followed by crystallization of the purified 9g from hexanes; yield 82%, mp 103°-105° C.
Other quinolines 2-9 were prepared in a similar manner using the appropriate ketimines 12 and lithium amide reagents.
Hydrobromide salts of 2-9
Non-crystalline quinolines 2-9 were transformed into crystalline hydrobromide salts. Thus, a solution of a quinoline derivative in ethanol was treated with a solution of hydrobromic acid in aqueous ethanol, and the resultant mixture was concentrated to precipitate the hydrobromide salt. The salt was crystallized from ethanol or the mixture of ethanol with hexanes. The composition of the salt was determined by elemental analysis.
II. Biologioal Activities of 4-[(Alkyl and Dialkyl)amino]quinolines
EXAMPLE 1
Intercalation of DNA and Amplication of the activity of Anticancer Agents
One method of enhancing the activity of currently available anticancer drugs is to identify compounds that alone may or may not have significant anticancer activity but that amplify the action of the drug when administered together. For example, bleomycin and phleomycin metal complexes have anticancer activity because they bind to DNA and disrupt the double helix. The anticancer activity of bleomycin and phleomycin can be enhanced by DNA intercalators and groove binding agents that distort the double helix. See generally: Strekowski, et al., "Molecular Basis for Anticancer Drug Amplification: Interaction of Phleomycin Amplifiers with DNA," J. Med. Chemistrv Vol. 29, 1311 (1986); Strekowski, et al., "A Non-classical Intercalation model for a Bleomycin Amplifier," Anti-Cancer Druo Design Vol. 2, 387 (1988).
The 4-[(alkyl and dialkyl)amino]quinolines of the present invention are capable of inserting into and distorting the DNA helix. The interaction of these compounds with nucleic acids involves two features: (i) electrostatic attraction of the protonated amino group with the anionic backbone of the nucleic acid an (ii) intercalation of the quinoline derivative with the nucleic acid acid base-pairs. This double-interaction mode is important for the enhancement (amplification) of anti-cancer activity of nucleic acid-interacting drugs such as phleomycin and bleomycin. It appears that the presence of an additional amino substituent in the 4-amino side group enhances the interaction of the substituted quinoline with nucleic acids. This additional amino substituent is strongly basic (pk a ˜9-10) and is, therefore, protonated under physiological conditions.
The ability of a compound to insert into DNA can be measured by increase in DNA viscosity (using viscometric titration with isolated DNA samples), flow dichroism, and is evident from a downfield shift of DNA 31 P signals, and an upfield shift of hydrogen-bonded base-pair imino protons. In addition, the NMR signals for the aromatic protons of the quinoline are shifted upfield depending on the extent of overlap of the pi clouds of the quinoline and the base pairs in the DNA. Detailed procedures for the measurement of the extent of intercalation of the quinoline derivatives with DNA are provided below. Sonicated calf thymus DNA (Worthington Biochemical) is used in the viscometric titrations (800±100 base pairs) as well as the NMR experiments (200±50 base pairs). An unsonicated DNA sample is used in the flow dichroism studies.
A. Viscometric Titration with DNA.
All DNA samples are purified from residual proteins and characterized as previously described (Wilson, et al., Biopolymers 24, 1941 1985)). Plasmid pBR322 for the viscometric titrations is obtained from Eschericia coli strain K336 grown in Luria-Bertani media with 25 μgl -1 ampicillin and amplified with 100mgl -1 chloramphenicol (Hillen, et al., Biochemistry 20, 3748 (1981)). After the usual workup described by Garger, et al., Biochem. and BioDhvs Res. Comm. 117, 835 (1983), the plasmid (concentration of 3×10 -3 M DNA bases) is obtained by high performance liquid chromatography on a 10×25 mm Nucleogen DEAE 4000-7 column (5 M urea, 20 mM K 3 PO 4 , pH 6.9, linear increasing of concentration of KCl from 0.3 M to 1.5 M over 40 minutes, flow rate 2 ml min -1 ) followed by dialysis in a PIPES 00 buffer at 4° C. Electrophoresis shows greater than 95% of supercoiled form I, greater than 5% of circular form II, and an absence of linear form III. When stored with one drop of chloroform at 4° C., the sample does not significantly change its composition over a period of one month.
Viscometric titrations are conducted at 25°±0.01° C. in PIPES 00 Buffer as previously described by Jones, et al., in Nucleic Acids Research 8, 1613 (1980)). The ethidium-induced unwinding angle of 26 is taken as a reference value for the experiments with a superhelical DNA sample (Wang, J. Mol. Biol. 89, 783 (1974)). The unwinding experiments are conducted at a range of DNA concentrations and the maximum viscosity changes are plotted by the Vinograd method (Revet, et al., Nature New Biology 229, 10 (1971)).
B. Flow Diohroism
Flow dichroism experiments are carried out in a PIPES buffer at 25° C. at a ratio of 0.10 (compound/base pair) and a DNA base pair concentration of 3.65 mM as described by Banville, et al., Biopolymers 25, 1837 (1986)).
C. Nuclear Magnetic Resonance Studies.
Measurements of the effect of the new quinolines on DNA imino protons and 31 P NMR signals are performed as described by Wilson, et al., J. Am. Chem. Soc. 107, 4989 (1985). The changes in chemical shift of the aromatic protons of the new quinolines on addition of DNA are measured as follows. Proton (270-MHz) NMR spectra are obtained on a JEOL GX 270 spectrometer under the following conditions: typically 2000 scans; 2.15-s pulse repetition rate; 0.1-Hz line broadening; 16K data points; TSP reference; 4000-Hz spectral width; 100% D 2 O/phosphate buffer containing 15 mM NaH 2 PO 4 , 0.1 mM EDTA, 0.1 M NaCl; 5 mM quinoline; temperature 60° C.; 0.8-mL sample volume in a 5-mm NMR tube. The high temperature is used to obtain monomer ligand at NMR concentrations and to obtain fast exchange between free and bound compound. Spectrophotometric measurements indicate that the DNA Tm under these conditions is greater than 75° C. and that the DNA is, thus, in the native state in the NMR experiments.
Bleomycin Amplification
Bleomycin-medicated degradation of DNA results in decreases in the viscosity of DNA solution. The relative viscosity changes in the absence and presence of amplifiers are used as a highly sensitive test for bleomycin amplification, as described by Strekowski et al. in J. Med. Chem. Vol 31, 1231 (1988).
In the experiment the molecular ratios of DNA to bleomycin and oxygen to DNA should be high. The concentration of ferrous ion remains practically constant throughout the reaction because a relatively high initial concentration of the ferrous ion and dithiothreitol, an iron reducing agent, are used. Under these conditions the DNA viscosity changes over time can be described by the following biphasic equation (1), ##EQU1## where n o is the initial reduced specific viscosity for DNA before the addition of bleomycin, n is the reduced specific viscosity for DNA at the reaction (degradation) time t, k f is the apparent rate constant for the first (fast) process, and k s is the apparent rate constant for the second (slow) process. Both fast and slow processes are enhanced in the presence of bleomycin amplifiers. These effects are concentration dependent, that is the viscosity is decreasing faster with increasing concentrations of the amplifiers. The best bleomycin amplifiers are quinolines at general structures 3,4,6,7, and 9 containing an additional amnio group in the 4-alkylamino or 4-dialkylamino substituent.
DNA-Bleomycin Reactions: Concentrations. PIPES 00 buffer (without EDTA, pH 7.00) and high molecular weight DNA are used in all experiments with bleomycin. Stock solutions (37° C.) are added in the order given below to the PIPES 00 buffer in a viscometer to reach the final volume of 1.5 mL and the following final concentrations: calf thymus DNA, 2.34×10. M (concentration of nucleotide equivalents); compounds 2-9, 15, 4.3×10 -5 M or 4.3×10 -4 M (ratios of 0.37 or 3.7 of molecules per DNA base pair, respectively); FeSO , 7.4×10 -6 M; dithiothreitol, 18×10 -4 M; bleomycin, 1.1×10 -6 M.
EXAMPLE 2
Inhibition of Replication of HIV virus in vitro
The 4-[(alkyl or dialkyl)amino]quinolines exhibit an inhibitory effect on retroviruses, and in particular, human immunodeficiency virus (HIV).
The median effective concentrations (EC 50 ) of selected quinolines against HIV-1 were determined in human blood mononuclear (PBM) cells infected with HIV-1 (strain LAV) as described below. The results are provided in Table 16. As shown in Table 16, the EC 50 values for the quinolines tested range from 0.9 to 68.2. It appears that the presence of a heteraromatic substituent at position 2 of the quinoline enhances the anti-HIV-1 activity of the 4-[(alkyl and dialkyl)amino]quinoline derivative. The anti-HIV-1 activity appears to be diminished in compounds with large substituents attached to the 4-amino group.
The following procedure was used to determine the EC 50 values for selected compounds.
A. Three-day-old phytohemagglutinin-stimulated PBM cells (10 6 cells/ml) from hepatitis B and HIV-1 seronegative healthy donors were infected with HIV-1 (strain LAV) at a concentration of about 100 times the 50% tissue culture infectious dose (TICD 50) per ml and cultured in the presence and absence of various concentrations of quinolines.
B. Approximately 45 minutes after infection, medium, with the compound to be tested (2 times the final concentration in medium) or without compound, was added to the flasks (5 ml; final volume 10 ml). AZT was used as a positive control.
C. The cells were exposed to HIV (about 2×10 5 dpm/ml, as determined by reverse transcriptase assay) and then placed in a CO 2 incubator. HIV-1 (strain LAV) was obtained from the Center for Disease Control, Atlanta, Ga. The methods used for culturing the PBM cells, harvesting the virus and determining the reverse transcriptase activity were those described by McDougal et al. (J. Immun. Meth. 76, 171-183, 1985) and Spira et al. (J. Clin. Meth. 25, 97-99, 1987), except that fungizone was not included in the medium (see Schinazi, et al., Antimicrob. Agents Chemother. 32, 1784-1787 (1988)). The reverse transcriptase activity in the virus-infected control was about 2×10 5 dpm per ml. Blank and uninfected cell control values were about 300 and 1,000 dpm, respectively.
D. On day 6, the cells and media were transferred to a 15 ml tube and centrifuged at about 900 g for 10 minutes. Five ml of supernatant were removed and the virus concentrated by centrifugation at 40,000 rpm for 30 minutes (Beckman 70.1 Ti rotor). The solubilized virus pellet was processed for determination of the levels of reverse transcriptase. Results are expressed in dpm/ml of sampled supernatant.
The median effective (EC 50 ) concentrations for derivatized quinolines, were determined by the median effect method (Antimicrob. Agents Chemother. 30: 491-498, 1986). Briefly, in the median effect method, the percent inhibition of virus, as determined from measurements of reverse transcriptase, is plotted versus the micromolar concentration of compound. The EC 50 is the concentration of compound at which there is a 50% inhibition of viral replication.
EXAMPLE 4
Determination of Toxicity of 4-[(Alkyl and Dialkyl)amino]quinolines in Peripheral Blood Mononuclear Cells
Assay.
The toxicity of 6a,6d,8a, and 8c were determined in nitrogen-stimulated PBM cells (3.8×10 5 cells/ml) cultured in the presence and absence of compounds under conditions similar to those used for the antiviral assay described above but without virus. The cells were counted after 6 days using a hemacytometer and the trypan blue exclusion method, as described by Schinazi et al., Antimicrobial Agents and Chemotherapy, 22(3), 499 (1982).
Results.
The effect of the compounds on the growth of uninfected human PBM cells in culture is used as an indicator of the toxicity of the test compound to the normal viability of cells. The IC 50 is the concentration of compound which inhibits 50% of normal, uninfected, cell growth. Compounds 6a,6d,8a, and 8c were found to have an IC 50 of greater than 100 μM. Compound 8a has an IC 50 of 1.2.
Modifications and variations of the present invention, new 4-[alkyl and dialkyl)amino]quinolines and their method of preparation, will be obvious to those skilled in the art from the foregoing description. Such modifications and variations are intended to come within the scope of the appended claims.
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Novel 4-[(alkyl or dialkyl)amino]quinolines are disclosed that are prepared by condensin
BACKGROUND OF THE INVENTION
The United States government has rights in this invention as a result of a grant from the NIAID of the National Institute of Health, Bethesda, Md.
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RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2011-171780 filed on Aug. 5, 2011, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a phase compensation circuit of a voltage regulator and reduction in power consumption thereof.
2. Description of the Related Art
As a conventional voltage regulator that stably operates regardless of output capacity or output resistance, the circuit illustrated in FIG. 6 has been known.
The conventional voltage regulator is constituted of a reference voltage circuit 101 , a differential amplifier circuit 102 , a PMOS transistor 106 , a phase compensation circuit 460 , resistors 108 and 109 , a ground terminal 100 , an output terminal 121 , and a supply terminal 150 . The phase compensation circuit 460 is constituted of a constant current circuit 405 , NMOS transistors 401 , 406 , 403 and 408 , a capacitor 407 , and a resistor 404 . The differential amplifier circuit 102 is constituted of a one-stage amplifier illustrated in FIG. 7 .
Regarding the connection, an inverting input terminal of the differential amplifier circuit 102 is connected to the reference voltage circuit 101 , a non-inverting input terminal thereof is connected to a connection point of the resistors 108 and 109 , and an output terminal thereof is connected to the gate of the PMOS transistor 106 and the drain of the NMOS transistor 401 . The other end of the reference voltage circuit 101 is connected to the ground terminal 100 . The source of the NMOS transistor 401 is connected to the drain of the NMOS transistor 403 , and the gate thereof is connected to the gate and the drain of the NMOS transistor 406 . The source of the NMOS transistor 403 is connected to the ground terminal 100 , and a gate thereof is connected to the resistor 404 and the drain of the NMOS transistor 408 . The source of the NMOS transistor 408 is connected to the ground terminal 100 , the gate thereof is connected to the other end of the resistor 404 and the capacitor 407 , and the drain thereof is connected to the source of the NMOS transistor 406 . The drain of the NMOS transistor 406 is connected to a constant current circuit 405 , and the other end of the constant current circuit 405 is connected to the supply terminal 150 . The source of the PMOS transistor 106 is connected to the supply terminal 150 , and the drain thereof is connected to the output terminal 121 , the other end of the capacitor 407 , and the other end of the resistor 108 . The other end of the resistor 109 is connected to the ground terminal 100 (refer to, for example, non-patent document 1).
PRIOR ART DOCUMENTS
Non-Patent Documents
[Non-Patent Document 1] IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS-I: REGULAR PAPERS, VOL. 54, NO. 9, SEPTEMBER 2007 (FIG. 13)
However, according to the conventional art, the phase compensation circuit 460 is adapted to pass a part of the current at the output terminal of the differential amplifier circuit 102 to the ground. Hence, current passes to an output terminal from a transistor 503 of the differential amplifier circuit 102 , causing imbalance in the current flowing to input transistors 501 and 504 with consequent occurrence of an offset. This has been posing a problem in that it is difficult to obtain an accurate output voltage.
Further, fixed current is constantly supplied for operating the phase compensation circuit 460 regardless of the magnitude of a load current, so that unnecessarily large power has been consumed for a light load.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to solve the problem described above by providing a voltage regulator capable of stably operating independently of output capacity or output resistance to obtain an accurate output voltage and also capable of reducing power consumed in the case of a light load.
To this end, there is provided a voltage regulator including: an error amplifier circuit which amplifies and outputs the difference between a reference voltage and a divided voltage obtained by dividing a voltage output by an output transistor thereby to control the gate of the output transistor; and a phase compensation circuit, wherein the phase compensation circuit includes: a first transistor having a drain thereof connected to an output terminal of the error amplifier circuit; a second transistor having a drain thereof connected to a gate of the first transistor and a gate thereof connected to the gate of the first transistor through a resistor; a current mirror circuit connected to an output terminal of the error amplifier circuit, a drain of the first transistor, and the drain of the second transistor; and a capacitor connected between the gate of the second transistor and a drain of the output transistor.
The voltage regulator equipped with the phase compensation circuit in accordance with the present invention is capable of preventing the occurrence of an offset caused by disturbed balance of current passing through an input transistor of a differential amplifier circuit, thus allowing an accurate output voltage to be obtained, and also capable of operating with stability and high speed independently of output capacity or output resistance. Moreover, the voltage regulator according to the present invention is capable of controlling power consumption to a minimum for a light load.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram illustrating a first embodiment of a voltage regulator;
FIG. 2 is a circuit diagram illustrating a first embodiment of a current mirror circuit;
FIG. 3 is a circuit diagram illustrating a second embodiment of the current mirror circuit;
FIG. 4 is a circuit diagram illustrating a third embodiment of the current mirror circuit;
FIG. 5 is a circuit diagram illustrating a fourth embodiment of the current mirror circuit;
FIG. 6 is a circuit diagram illustrating a conventional voltage regulator; and
FIG. 7 is a circuit diagram illustrating a differential amplifier circuit constituted of a one-stage amplifier.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described with reference to the accompanying drawings.
First Embodiment
First, the configuration of a voltage regulator will be described. FIG. 1 is a circuit diagram illustrating the voltage regulator in accordance with the present invention.
The voltage regulator is constituted of a reference voltage circuit 101 , a differential amplifier circuit 102 , a phase compensation circuit 160 , a PMOS transistor 106 , resistors 108 and 109 , a ground terminal 100 , an output terminal 121 , and a supply terminal 150 . The phase compensation circuit 160 is constituted of NMOS transistors 112 and 114 , a capacitor 115 , a resistor 113 , and a current mirror circuit 110 . The current mirror circuit 110 has four terminals, namely, a terminal 1 , a terminal 2 , a terminal 3 , and a terminal 4 , and outputs a predetermined current from the terminal 2 or the terminal 3 on the basis of a voltage supplied to the terminal 1 .
The following will describe the connection of an element circuit of the voltage regulator.
The inverting input terminal of the differential amplifier circuit 102 is connected to the reference voltage circuit 101 , the non-inverting input terminal thereof is connected to the connection point of the resistors 108 and 109 , and the output terminal thereof is connected to the gate of the PMOS transistor 106 , the drain of the NMOS transistor 112 , and the terminal 1 and the terminal 2 of the current mirror circuit 110 . The other end of the reference voltage circuit 101 is connected to the ground terminal 100 . The source of the NMOS transistor 112 is connected to the ground terminal 100 , and the gate thereof is connected to the resistor 113 and the drain of the NMOS transistor 114 . The gate of the NMOS transistor 114 is connected to the other end of the resistor 113 and the capacitor 115 , the drain thereof is connected to the terminal 3 of the current mirror circuit 110 , and the source thereof is connected to the ground terminal 100 . The terminal 4 of the current mirror circuit 110 is connected to the supply terminal 150 . The source of the PMOS transistor 106 is connected to the supply terminal 150 , the drain thereof is connected to the output terminal 121 , the other end of the capacitor 115 , and the other end of the resistor 108 . The other end of the resistor 109 is connected to the ground terminal 100 .
The operation of the voltage regulator will now be described.
As the voltage of the output terminal 121 increases, the voltage of a node 120 increases accordingly. If the voltage of the node 120 becomes higher than the voltage of the reference voltage circuit 101 , then the output voltage of the differential amplifier circuit 102 increases. This causes the gate voltage of the PMOS transistor 106 to increase, so that the drain current of the PMOS transistor 106 decreases and the voltage at the output terminal 121 decreases. Thus, the output terminal is controlled to have a constant desired voltage.
In the voltage regulator illustrated in FIG. 1 , poles are generated at frequencies indicated by the following expressions.
fp
1
=
1
2
π
{
R
1
Gm
P
106
R
out
(
Gm
N
114
R
113
C
115
)
}
(
1
)
fp
2
=
Gm
P
106
(
Gm
N
114
R
113
C
115
)
2
π
C
out
C
G
(
2
)
where R 1 denotes a parasitic resistance component of an output impedance of the differential amplifier circuit 102 ; R out denotes a load resistance connected to the output terminal 121 ; Gm P106 denotes the transconductance of the PMOS transistor 106 ; Gm N114 denotes the transconductance of the NMOS transistor 114 ; R 113 denotes the resistance value of the resistor 113 ; C 115 denotes the capacitance value of the capacitor 115 ; C out denotes the output capacitance to be connected; and C G denotes the gate capacitance value of the PMOS transistor 106 .
As understood from expressions 1 and 2, the positions of the first pole and the second pole can be adjusted by the resistor 113 , the capacitor 115 , and the transconductance of the NMOS transistor 114 , thus permitting adjustment for the stable operation independently of the output resistance Rout and the output capacitance C out .
The output terminal of the differential amplifier circuit 102 is connected to the drain of the NMOS transistor 112 and the current mirror circuit 110 , so that the current to the NMOS transistor 112 can be supplied from the current mirror circuit 110 . Further, no current passes from the output terminal of the differential amplifier circuit 102 to the NMOS transistor 112 , so that there will be no offset occurring in a transistor of the input stage of the differential amplifier circuit 102 . This arrangement prevents fluctuations in the output voltage attributable to the offset, making it possible to accurately set an output voltage.
Based on the expressions given above, if the load resistance R out is sufficiently high, then the positions of the first pole and the second pole can be separated even when Gm N114 is small. In this case, Gm of a MOS transistor is denoted by the following expression.
Gm =(2 I DS μC OX W/L ) 1/2 (3)
Based on the above expression, if the load resistance R out is sufficiently high, then the stable operation can be achieved even when the drain current of the NMOS transistor 114 of the phase compensation circuit 160 is reduced.
Thus, the drive current can be controlled to remain low by limiting the value of current to be supplied to the phase compensation circuit 160 from the current mirror circuit 110 according to the magnitude of the current passing from the PMOS transistor 106 to the load resistance R out .
As described above, the voltage regulator in accordance with the present invention is capable of preventing the occurrence of an offset in the transistor of the input stage of the differential amplifier circuit 102 so as to prevent fluctuations in the output voltage attributable to the offset, thus permitting accurate setting of an output voltage. In addition, the consumption current of the phase compensation circuit 160 can be controlled to be low according to the magnitude of the current passed from the PMOS transistor 106 to the load resistance R out .
Second Embodiment
FIG. 2 is a circuit diagram illustrating a first embodiment of a current mirror circuit 110 related to the voltage regulator in accordance with the present invention. The current mirror circuit 110 is constituted of PMOS transistors 201 , 202 , 203 , 204 , and NMOS transistors 205 and 206 . The source of the PMOS transistor 201 is connected to a supply terminal 150 , the gate thereof is connected to a node 130 , which is the output of a differential amplifier circuit 102 , and the drain thereof is connected to the drain of the NMOS transistor 205 . The source of the NMOS transistor 205 is connected to a ground terminal 100 , and the gate thereof is connected to the drain of the NMOS transistor 205 and the gate of the NMOS transistor 206 . The source of the NMOS transistor 206 is connected to the ground terminal 100 , and the drain thereof is connected to the drain of the PMOS transistor 202 . The source of the PMOS transistor 202 is connected to the supply terminal 150 and the gate thereof is connected to the drain of the PMOS transistor 202 and the gates of the PMOS transistor 203 and the PMOS transistor 204 . The source of the PMOS transistor 203 is connected to the supply terminal 150 , and the drain thereof is connected to the drain of the NMOS transistor 112 of the phase compensation circuit 160 . The source of the PMOS transistor 204 is connected to the supply terminal 150 , and the drain thereof is connected to the drain of an NMOS transistor 114 of the phase compensation circuit 160 .
In the current mirror circuit according to the first embodiment, the gate voltage of the PMOS transistor 106 , which is the output of the differential amplifier circuit 102 , is input to the gate of the PMOS transistor 201 . The drain current of the PMOS transistor 201 changes according to the value of current passed from the PMOS transistor 106 to the load resistor. The drain current of the PMOS transistor 201 is mirrored on the PMOS transistor 202 by the current mirror formed of the NMOS transistors 205 and 206 , and a mirror current, which is based on the value of the current supplied from the PMOS transistor 106 to the load resistance, is passed to the phase compensation circuit 160 by the current mirror formed of the PMOS transistors 202 , 203 and 204 .
As described above, the voltage regulator in accordance with the present invention, which has the phase compensation circuit with the current mirror circuit of the first embodiment, is capable of preventing the occurrence of an offset in the transistor of the input stage of the differential amplifier circuit 102 so as to prevent fluctuations in the output voltage attributable to the offset, thus permitting accurate setting of an output voltage. In addition, the consumption current of the phase compensation circuit 160 can be controlled to a low level according to the magnitude of the current passed from the PMOS transistor 106 to the load resistance R out .
Third Embodiment
FIG. 3 is a circuit diagram illustrating a second embodiment of a current mirror circuit 110 related to the voltage regulator in accordance with the present invention. The current mirror circuit of the second embodiment has additional NMOS transistors 301 and 302 to enable the current mirror circuit to be driven at a low voltage and to provide an accurate current mirror. The NMOS transistor 301 is added between a PMOS transistor 201 and an NMOS transistor 205 , the gate of the NMOS transistor 205 being connected to the drain of the NMOS transistor 301 . The NMOS transistor 302 is added between a PMOS transistor 202 and an NMOS transistor 206 , the gate of the NMOS transistor 206 being connected to the drain of the NMOS transistor 301 . The gate voltages for the NMOS transistors 301 and 302 are supplied from another circuit.
In the current mirror circuit of the second embodiment, the NMOS transistors 301 and 302 act as a cascode circuit to improve the accuracy of the current mirror circuit of the NMOS transistors 205 and 206 . Further, the gate voltages for the NMOS transistors 301 and 302 are supplied from another circuit, thereby making it possible to control the upper limit of the consumption current of the cascode type current mirror circuit formed by the NMOS transistors 205 , 206 , 301 and 302 to a low level.
As described above, the voltage regulator in accordance with the present invention, which has the phase compensation circuit with the current mirror circuit of the second embodiment, is capable of preventing the occurrence of an offset in the transistor of the input stage of the differential amplifier circuit 102 so as to prevent fluctuations in the output voltage attributable to the offset, thus permitting accurate setting of an output voltage. In addition, the consumption current of the phase compensation circuit 160 can be controlled to a low level according to the magnitude of the current passed from the PMOS transistor 106 to the load resistance R out , making it possible to limit the drive current of the phase compensation circuit 160 so as to prevent the drive current from becoming excessive in the case where the value of the current passed from the PMOS transistor 106 to the load resistance is large.
Fourth Embodiment
FIG. 4 is a circuit diagram illustrating a third embodiment of a current mirror circuit 110 related to the voltage regulator in accordance with the present invention. In the current mirror circuit of the third embodiment, an NMOS transistor 401 has been added as a current source between the PMOS transistor 201 and the NMOS transistor 205 . The NMOS transistor 401 is a depletion-type transistor, the gate thereof being connected to the drain of the NMOS transistor 205 .
A depletion-type transistor having a fixed voltage between the gate and the source acts as a constant-current source when the operation state thereof reaches a saturation range. When the value of the load current from the PMOS transistor 106 referred to by the PMOS transistor 201 exceeds a predetermined value, the NMOS transistor 401 acts as the constant-current source, thereby restricting the drive current of the phase compensation circuit 160 .
As described above, the voltage regulator in accordance with the present invention, which has the phase compensation circuit with the current mirror circuit of the third embodiment, is capable of preventing the occurrence of an offset in the transistor of the input stage of the differential amplifier circuit 102 so as to prevent fluctuations in the output voltage attributable to the offset, thus permitting accurate setting of an output voltage. In addition, the consumption current of the phase compensation circuit 160 can be controlled to a low level according to the magnitude of the current passed from the PMOS transistor 106 to the load resistance R out , making it possible to limit the drive current of the phase compensation circuit 160 so as to prevent the drive current from becoming excessive in the case where the value of the current passed from the PMOS transistor 106 to the load resistance is large.
Fifth Embodiment
FIG. 5 is a circuit diagram illustrating a fourth embodiment of a current mirror circuit 110 related to the voltage regulator in accordance with the present invention. In the current mirror circuit of the fourth embodiment, a constant-current source circuit 506 has been added to replace the NMOS transistor 205 . The constant-current source circuit 506 is constituted of PMOS transistors 501 and 502 , NMOS transistors 503 and 504 , and a resistor 505 .
The source of the PMOS transistor 501 is connected to the drain of a PMOS transistor 201 , the gate thereof is connected to the drain of the PMOS transistor 501 , and the drain thereof is connected to the drain of the NMOS transistor 503 . The source of the PMOS transistor 502 is connected to the drain of the PMOS transistor 201 , the gate thereof is connected to the drain of the PMOS transistor 501 , and the drain thereof is connected to the drain of the NMOS transistor 504 . The gate of the NMOS transistor 503 is connected to the drain of the NMOS transistor 504 , and the source thereof is connected to the resistor 505 . The gate of the NMOS transistor 504 is connected to the drain of the NMOS transistor 504 , and the source thereof is connected to a ground terminal 100 . The other end of the resistor 505 is connected to the ground terminal 100 .
The PMOS transistors 501 and 502 constitute a current mirror circuit. The NMOS transistors 503 and 504 constitute a current mirror circuit having the gates thereof interconnected, while the source of the NMOS transistor 503 is connected to the ground terminal 100 through a resistor. Hence, a voltage drop takes place in the resistor 505 due to the drain current of the NMOS transistor 503 , causing the gate-source voltage of the NMOS transistor 503 to decrease accordingly. The voltage drop in the resistor 505 is determined by the difference in value K between the NMOS transistors 503 and 504 or the difference in value K between the PMOS transistors 501 and 502 and the value of the resistor 505 , thus providing a constant-current source circuit that does not depend upon a supply voltage.
When the value of the load current from the PMOS transistor 106 referred to by the PMOS transistor 201 exceeds a predetermined value, the constant-current source circuit 506 acts as the constant-current circuit, thereby restricting the value of the drive current of the phase compensation circuit 160 .
As described above, the voltage regulator in accordance with the present invention, which has the phase compensation circuit with the current mirror circuit of the fourth embodiment, is capable of preventing the occurrence of an offset in the transistor of the input stage of the differential amplifier circuit 102 so as to prevent fluctuations in the output voltage attributable to the offset, thus permitting accurate setting of an output voltage. In addition, the consumption current of the phase compensation circuit 160 is controlled to a low level according to the magnitude of the current passed from the PMOS transistor 106 to the load resistance R out , making it possible to limit the drive current of the phase compensation circuit 160 so as to prevent the drive current from becoming excessive in the case where the value of the current passed from the PMOS transistor 106 to the load resistance is large.
|
A voltage regulator has a phase compensation circuit which changes consumption current according to load current thereby to reduce consumption current. The phase compensation circuit includes: a first transistor having a drain connected to an output terminal of an error amplifier circuit; a second transistor having a drain connected to a gate of the first transistor and a gate connected to the gate of the first transistor; a current mirror circuit connected to the output terminal of the error amplifier circuit, a drain of the first transistor, and the drain of the second transistor; and a capacitor connected between the gate of the second transistor and a drain of an output transistor. Thereby, current consumed by the phase compensation circuit can be changed according to the load current, resulting in that the voltage regulator consumes less current.
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FIELD OF THE INVENTION
[0001] The present invention relates to a substrate for vegetation which may be used in the form of a panel, building block, tile or brick, for example.
[0002] More particularly, the present invention relates to a module permitting the juxtaposition of a porous wall with interconnected spaces with a substrate as a support for vegetation, in particular in a vertical position and in an urban environment.
PRIOR ART
[0003] Substrates, for example modules, for vegetation are generally known in the prior art.
[0004] For example, the publication WO 2006/010846 A1 relates to a structure for a wall provided with vegetation designed for urban landscaping and for producing noise screens, partition walls, fencing around building sites, etc. Said publication discloses, more particularly, boxes of prismatic shape provided to be juxtaposed and/or superposed, each box being highly perforated and filled, for example, with compost in which the roots of vegetation planted in the compost are able to grow. Each box has wire-mesh or chain-link faces and is lined internally with a mat or fabric on its front and rear faces provided with perforations or slits through which the vegetation may be planted in the compost. More specifically, the front and rear faces of at least the boxes are covered on the inside with a mat or fabric fixed by stapling or bonding, which ensures the retention of the planting substrate. Plants are placed through the perforations or slits of the mat or fabric so that their roots grow in the planting substrate.
[0005] Said mat or fabric may fulfill various roles: namely, apart from retaining the compost, the retention of water or moisture, protection, a visual guide for the planting of vegetation according to a predetermined pattern, decoration, a lighting support, etc.
[0006] According to this known structure, the vegetation is thus directly planted in the substrate or compost and the mat or fabric only fulfills the roles indicated above.
[0007] The publication WO 2004/061255 A1 discloses a further substrate system. In this case it consists of a building block having two zones in which soil is placed where plants are able to grow directly.
[0008] The publication US 2008/0003445 A1 discloses a ceramic brick which comprises a shaped ceramic porous part to grow plants in combination with a support. The plants are directly planted in the porous ceramic, without the use of a substrate.
[0009] The document DE 39 32 644 discloses a further system to grow plants in a frame which may be hooked on vertically.
[0010] The publication US 2004/0010971 discloses a system in the form of a tube to grow plants. The tube is hollow and contains the substrate for the plants. The tube further comprises openings permitting the plants to grow out of the tube, said plants being sown in the substrate.
[0011] The publication US 2003/0196376 illustrates a further system in the form of a post combined with containers to grow the plants. The containers are shaped to contain soil, for example, and their external surfaces comprise openings to permit the passage of plants.
[0012] The publications DE 10 2005 063 133 A1, GB 2 412 558 A and DE 20 2004 000 438 U1 disclose further examples of substrates for vegetation.
SUMMARY OF THE INVENTION
[0013] The object of the invention is to improve the known systems.
[0014] More particularly, an object of the invention is to propose a simple system to form elements with vegetation, for example walls/partitions to influence the urban environment, the thermal characteristics of a building, the control of rainwater, the acoustics and the pollution control.
[0015] The invention is useful for facades of all heights, made of materials which are porous and hybrid, which comprise inorganic substances or plants and/or are synthetic—or a material in the form of a soil mix applied to the wall and which might contain seeds. This is known as a “seeded wall”.
[0016] The invention also relates to a system which makes it possible to cultivate plants vertically or in a similar position.
[0017] According to the present invention, a “container module” is constructed, for example, from concrete or another non-porous material. The module comprises at least one face or wall which is porous, the spaces or porosities thereof being interconnected. The porous face is combined with an (inorganic and/or organic) substrate for the purpose of providing vegetation in new or existing facades. The module may take different forms, for example, in particular that of a building block, a tile, a panel or a brick according to the embodiments disclosed in detail in the present application.
[0018] The module according to the invention comprises a rigid shell, which is solid and self-supporting and comprises, as indicated above, at least one porous face or wall comprising interconnected spaces or porosities which permit the roots to be established. The provision of vegetation in the module is carried out by sowing in the spaces or porosities and the plants being directly rooted into the rigid surface where the porosities are interconnected, which forms the association of a volume of roots in the porous face and an environment where the roots grow and where water circulates in the substrate. As a result, the roots pass through an inert element, for example of 2 to 3 cm (depending on the thickness of the porous face), before finding water and food in the substrate, in contrast to what is implemented in the prior art, see for example WO 2006/010846 A1 cited above where the vegetation is planted directly into the compost. Thus the module according to the invention proposes a way of colonizing the spaces and porosities of the porous face by the vegetation which is planted there.
[0019] The vegetation grows naturally in the porosities of the face of the module. The size of the porosities does not permit seeds of ligneous plants to germinate on said surface.
[0020] Preferably, the module with the porous face(s) according to the invention has the following features:
its face(s) or porous wall(s) is(are) chemically inert (no chemical interaction with the environment); its wall(s) consists(consist) of a frost-proof material (i.e. resistant to the cycles of freezing and thawing) and is heat-resistant, for example a ceramic or other equivalent material; it comprises a surface which permits the establishment of roots in its porous surface. It forms an element of which (at least) one of the faces or wall is permeable, namely the face comprising the interconnected spaces or macro-porosities, said face being formed from a non-porous material with interconnected spaces which form said porous part; for example, it is used to construct a wall of vegetation on an inorganic substrate; it is formed by a rigid shell larger than 5 mm which is solid and self-supporting; the permeability of the substrate is greater than that of the shell; it forms a module, the layered structure and the materials thereof acting as an anti-noise wall.
[0028] Preferably, the size of the spaces (porosities) is 1 to 3 mm, which permits the establishment of roots in the porosities and the selection of the desired roots as a result of capillary action which is produced from the inside to the outside (and not in reverse). Other sizes of porosities are naturally possible depending on the circumstances.
[0029] Preferably, the module is entirely inorganic and solid and the interconnected spaces are smaller over the first 2-3 centimeters and wider over the last 4-5 centimeters of the thickness, which forms a porosity gradient.
[0030] Said porosity gradient illustrated in FIG. 8 allows the plants to be anchored in a first layer where the spaces are smaller and for water to circulate to the rear, irrigating the roots which pass through the porosities in the layer where the spaces are wider.
[0031] The principle of a porosity gradient may be extended to replace the substrate by a solid free-draining material, said material being the same as that used to form the porous face but with larger porosities. Typically, to produce such an embodiment of the invention, plates (for example ceramic plates) are juxtaposed, said plates having porosities or porosity gradients of different sizes.
[0032] The advantages of this entirely inorganic module according to the invention are, in particular, as follows:
it is formed from a single material; the water is retained in the concave areas of the spaces or porosities; hydroponic system; soil-less system (in the case of the free-draining solid material).
[0037] Advantageously, the module is combined with an irrigation system. Preferably, the irrigation system is not in direct contact with the substrate but it is remote therefrom (for example approximately 5 mm from the soil). Thus the roots do not block up the drip-feeders of the watering system. Naturally, it is possible to use other equivalent means to avoid the flow being blocked by the roots.
[0038] The water which circulates in the substrate only escapes through the rigid shell in the form of vapor.
[0039] The advantages of the module according to the invention are numerous:
the module is resistant to UV, fungi and algae; there is never any surface water but this is present in the soil or the compost (substrate); maintenance is easy; watering is carried out in the substrate contained in the module, for example by an irrigation system, the face with interconnected spaces remaining aerated and thus dry; it is lightweight, whilst remaining rigid; it permits shorter delivery times than other systems on the market; it involves reduced transport costs relative to other systems on the market, in particular without the transportation of plants; it forms an ecological system for the substrate in terms of primary energy (concrete).
[0048] The module according to the invention may be used in numerous ways, for example to form a wall. To form said wall, as a result, the desired number of modules according to the invention are stacked and an irrigation system as disclosed in more detail hereinafter is added thereto.
[0049] Naturally, said embodiments and dimensions are provided by way of non-limiting example and further embodiments are possible having different shapes but using the same principle as the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 shows in perspective an exploded view of the principle of the invention;
[0051] FIG. 2 illustrates a partial view in section of the principle of the invention;
[0052] FIGS. 3A to 3D illustrate an embodiment of a wall with building blocks according to the invention, FIG. 3C being a section along the axis A-A of FIG. 3B and FIG. 3D being a section along the axis B-B of FIG. 3B ;
[0053] FIGS. 4A to 4D illustrate an embodiment in the form of tiles, FIG. 4C being a section along the axis A-A of FIG. 4B and FIG. 4D being a section along the axis B-B of FIG. 4B ;
[0054] FIGS. 5A to 5D illustrate an embodiment in the form of panels, FIG. 5C being a section along the axis A-A of FIG. 5B and FIG. 5D being a section along the axis B-B of FIG. 5B ;
[0055] FIG. 6 illustrates the principle of the porosity in the present invention;
[0056] FIG. 7 illustrates the principle of the distribution of water in the present invention;
[0057] FIG. 8 illustrates the porosity gradient between the outside and inside (substrate side).
DETAILED DESCRIPTION
[0058] The principle of the invention is disclosed with reference to FIGS. 1 and 2 . The module has the shape of a building block, as illustrated by way of example. The module according to the invention thus comprises six faces 1 , 2 , 3 , 4 , 5 , and 6 as shown in FIG. 1 . A first face 1 is formed by an interconnected porous material. Preferably, the faces 2 and 3 are permeable but act as containers (for a substrate 7 ), the face 2 further permitting the support of a horizontal water supply. The faces 4 , 5 and 6 (rear and vertical sides in FIG. 1 ) are sealed and may be of different types. For example, the face 5 (or 6 or both) may contain a vertical water supply.
[0059] According to a variant, in the case of providing vegetation on two faces (in this case faces 1 and 4 , for example), said faces 1 and 4 are formed in a porous interconnected material according to the principle of the invention.
[0060] To produce the face of porous material, a material is used with interconnected porosities (for example of 2 to 3 mm) permitting the circulation of water, air and the anchoring of the roots.
[0061] To produce such an interconnected porous material, it is possible to use a ceramic powder combined with a second material which is subsequently dispensed with, thus forming this interconnected porous structure. Reference may be made, for example, to the teaching of the following publications: EP 1 140 731, U.S. Pat. No. 4,024,212 and WO 2006/018537 for the production of such porous faces.
[0062] Once the porous face/wall is produced, it is possible to join it to the concrete elements (for example) by pouring said concrete into the porosities of the porous part. The porous face or wall may thus have any shape which is useful or necessary depending on the desired use and it is possible to fix it to parts forming the remainder of the module by using the spaces or porosities. Naturally, further equivalent fixing means are possible.
[0063] Moreover, according to the present invention, the porous face is sown with seeds. Thus, the porosities allow the seeds to germinate. The concave areas where water and air circulate allow the plant to be rooted in this face and the roots then seek water and the nutrients in the substrate 7 by following the porosities or interconnected spaces.
[0064] According to the invention, the porosity of the face 1 is dimensioned so as to be sufficiently large for the plants to be able to take root, but prevents spontaneous ligneous vegetation from being established (trees and shrubs of which the roots may damage the structure of the building).
[0065] According to the invention, the basic structure of the module may comprise three elements (see FIG. 2 ):
[0066] 1. a porous material forming the interconnected porous face (for example 1 in FIGS. 1 and 2 ) which permits the plant to be anchored and to retain the substrate 7 ;
[0067] 2. a substrate 7 which permits the circulation of air, nutrients and water necessary for the growth of the plants;
[0068] 3. plants 8 suitable for the quantity of substrate available, the climate, the aspect, the vertical situation and the available water.
[0069] This structure allows the vegetation to live naturally, healthily and over a long period. It withstands environmental stresses (wind, frost and heat, etc.) and has acoustic and thermal properties.
[0070] Naturally, the sizes and shapes of the material and planting may be adapted to the requirements of the location (the orientation and reasons for the planting, composition, etc.)
[0071] The advantages of the structure according to the invention are numerous, in addition to those already mentioned above:
industrial manufacture of the product; the product is able to be easily handled (for example in the form of a building block or other equivalent element); it is easy to use; little maintenance is required; the properties of the soil are conserved, said material which is permeable to air and water allows the roots of the plants to be anchored, whilst freeing the soil from the effects of gravity.
[0077] Various uses and interpretations of the system may be combined:
dynamic-evolving system: the vegetation is selected according to the climate, their aspect (shady or sunny) and the type of management (extensive or intensive). Thus the plants, the thickness of the substrate and the water consumption vary. “extensive/autonomous” system: porous material with a small amount of substrate. Very low water requirement and very little maintenance. Lightweight system. it is also possible to conceive that the porous material is sufficient for certain plants, which have few requirements in terms of water and maintenance, to be established. “evapo-transpiration” system: porous material and larger substrate layer. Permits a wider choice of plants and the ability to influence the urban climate more effectively (more evapo-transpiration).
[0082] As indicated above, the system according to the invention is preferably conceived in the form of a module, each module being able to be used independently. It has all the necessary elements for providing vegetation thereon, namely: a porous face connected to a substrate and vegetation and a structure depending on its predicted use.
[0083] The structural system provides that the substrate is contained in the module whilst water is permitted to circulate.
[0084] Different sizes may be available, depending on the planned use, in particular.
[0085] It is possible for it to be used in different ways, according to different variants and with different plants.
[0086] It is manufactured industrially, sown with seeds in the factory or nursery and mounted in situ.
[0087] By way of non-limiting examples, the module of the invention may take the following forms:
[0088] A building block (see for example FIGS. 1 and 2 ) of which one of the facings, face 1 or faces 1 and 4 , is/are formed from a porous material with interconnected spaces in all spatial directions. The “building block” elements are handled easily, stacked up and juxtaposed. The internal volumes are continuous from top to bottom. Its rigidity also provides it with a structural function. FIG. 3A shows the principle of a wall formed from building blocks 20 according to the present invention.
[0089] More specifically, FIG. 3A is a front view of part of the wall composed of building blocks 20 in which the distribution of water is illustrated schematically by dashed-dotted lines. FIG. 3B is a view in elevation of a part of the wall, FIG. 3C is a sectional view along a horizontal plane A-A and FIG. 3D is a view in section along a vertical plane B-B.
[0090] More specifically, FIGS. 3C and 3D show the porous face 21 , the substrate 22 , the container 23 , for example corresponding to the faces 3 - 6 of FIG. 1 , and the irrigation system 24 which is both horizontal and vertical (see dashed-dotted lines of FIGS. 3A-3D ).
[0091] FIGS. 4A to 4D illustrate an embodiment in the form of a tile 30 of which the front face is composed of a porous material with interconnected spaces in all spatial directions, with a system for hooking onto the wall. According to the principle of the invention, the tiles comprise a porous face 31 , a substrate 32 , a container 33 and an irrigation system 34 (shown schematically by dashed-dotted lines of FIGS. 4A-4D and 4 C).
[0092] FIGS. 5A to 5D illustrate an embodiment in the form of a panel 40 stapled to a wall or intermediate structure which might comprise the face 41 formed from a porous material with interconnected spaces in all spatial directions. According to the present invention, the panel further comprises a substrate 42 , a container 43 and an irrigation system 44 (shown schematically by dashed-dotted lines in FIGS. 5A-5D ).
[0093] As indicated above, the module may be independent, provided with vegetation on one or both faces depending on its use and on the different embodiments disclosed above.
[0094] Preferably, a drip-type irrigation system is incorporated in the principle. The water circulates within the depth of the substrate, the excess being collected and reused, which limits wastage. The irrigation system is shown schematically in the figures disclosed above, as explained, and comprises for example pipes or conduits 24 , 34 , 44 with openings (for example slots) permitting the passage of the irrigation means (for example water) into the substrate. Further equivalent systems are naturally conceivable.
[0095] FIG. 6 illustrates the principle of the porosity in the module according to the invention. As may be seen, the flow of air (shown schematically by the arrows) may circulate in all directions.
[0096] FIG. 7 illustrates the principle of the distribution of water (as also shown in FIGS. 3A-3D , 4 A- 4 D and 5 A- 5 D). As indicated, the distribution is carried out in two perpendicular (or approximately perpendicular) planes, namely in a horizontal plane and a vertical plane. Naturally, depending on the position of the module (whatever the embodiment thereof) said planes may not be strictly horizontal and vertical.
[0097] The system permits improved insulation of the facade, thermal protection (both in summer and in winter) and, as a result, allows an energy saving.
[0098] The constituent elements (depth of substrate, choice of vegetation, water flow, etc.) are selected according to the orientation of the wall or aesthetic and ecological requirements.
[0099] According to variants, it is possible to color the porous material or further faces of the module. The use of a translucent material permits lighting of the facade by light-emitting diodes or other equivalent means.
[0100] The external porous surface may be planar or shaped.
[0101] The module may be used vertically, obliquely or horizontally.
[0102] Naturally, the examples given above are by way of illustration and do not have to be understood as limiting the scope of the present invention, for which variants are possible. Different embodiments may, for example, be of any size, determined for example by the application.
[0103] Moreover, the concept of a face or wall used to define the porous part of the module has to be understood as covering both an entire face or wall of the module but also a partial face or wall of the module. In this case, a given face or wall may have a porous part (according to the present invention, i.e. which comprises vegetation) and a non-porous part.
[0104] As disclosed above, the module may also have more than one porous face or wall according to the invention.
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The invention relates to a module for revegetating surfaces, for example walls, said module including at least one porous surface including interconnected porosities, said porous surface allowing the circulation of water and air and being used for sowing plants and anchoring the roots of said plants in said porosities, said roots growing in a substrate after having passed through said porosities.
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BACKGROUND
[0001] Field
[0002] The disclosed embodiments relate generally to herbal smoking blends and methods for preparing and using herbal smoking blends, and more particularly to herbal smoking blends having terpenoids added thereto.
[0003] Description of the Related Art
[0004] The smoking of various herbs can provide physiological and/or psychological effects, some of which can provide therapeutic benefits. For example, cannabis, also known as marijuana, is an herb that can be smoked for recreational purposes or therapeutic purposes, such as to treat nausea, pain, muscle spasticity, and loss of appetite, among other conditions. It has been observed that different herbs, including different species, different strains, or different varieties of an herb can have different therapeutic effects. Consequently, different species, strains, or varieties of herbs have been cultivated to achieve desired effects. Such cultivation, however, can be time-consuming, can limit the availability herbs with a desired effect, and may be cost-prohibitive for rare or difficult to cultivate plants.
[0005] Accordingly, there is a continuing need for methods of providing smoking herbs with desired effects.
SUMMARY
[0006] In one aspect, a method of preparing an herbal smoking blend comprises providing a smoking herb preparation. The method additionally comprises providing a terpenoid solution comprising a terpenoid. The terpenoid solution is added to the smoking herb preparation.
[0007] In another aspect, a smoking herb preparation system comprises a smoking herb. The system additionally comprises a terpenoid solution comprising at least one terpenoid. The system further comprises an applicator for administering a dose of the terpenoid solution to the smoking herb.
[0008] In another aspect, an herbal smoking blend comprises a smoking herb and a terpenoid at a terpenoid concentration, where the terpenoid is not naturally occurring in the smoking herb at the terpenoid concentration. In some embodiments, examples of a terpenoid include a terpenoid is selected from the group consisting of d-limonene, α-pinene, β-myrcene, linalool, pulegone, 1,8-cineole (eucalyptol), α-terpineol, terpineol-4-ol, p-cymene, borneol, Δ-3-carene, β-caryophyllene, caryophyllene oxide, nerolidol, phytol, Eugenol, Sabinene, Linalyl Acetate, Camphor, Chamazulene, beta-Farnesene, alpha-Humulene, Benzyl Benzoate, Benzyl Acetate, Geraniol, Geranyl Acetate, gamma-Terpinene, beta-Pinene, and combinations thereof, wherein the terpenoid is not naturally occurring in the smoking herb at the terpenoid concentration in the smoking herb blend. In some embodiments, the terpenoid is not naturally produced by smoking herb plant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a flow chart illustrating a method of preparing an herbal smoking blend, according to some embodiments.
[0010] FIG. 2 is a schematic illustration of a smoking herb preparation system comprising a smoking herb, according to some embodiments.
[0011] FIG. 3 is a schematic illustration of a smoking herb preparation system comprising a smoking herb, according to some other embodiments.
[0012] FIG. 4 is a schematic illustration of a smoking herb preparation system comprising a smoking herb, according to yet other embodiments.
DETAILED DESCRIPTION
[0013] Since the discovery of therapeutic effects of inhaled smoke of cannabis, the chemical origins of the therapeutic effects have been an intense area of research. The primary focus of the research into the chemical origins of the therapeutic effects of cannabis has been centered around a class of active compounds called cannabis phytocannabinoids. Phytocannabinoids, also referred to as cannabinoids, refer to a group of C 21 terpenophenolic compounds that are uniquely produced in cannabis. The most widely known phytocannabinoid is tetrahydrocannabidol (THC), which is known to be responsible for producing psychoactivity commonly associated with cannabis. Since the isolation of THC, other phytocannabinoids have been isolated and some have been associated with therapeutic effects. While over 100 phytocannabinoids are known to exist, a group of well-documented phytocannabinoids include tetrahydrocannabidol (THC), cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), tetrahdrocannabivarin (THCV), cannabidivarin (CBDV) and cannabinol (CBN). Some of the therapeutic effects of phytocannabinoids include, without being bound to any theory, euphoric effects (associated, for example, with THC and THCV), analgesic effects (associated, for example, with THC, CBD and THCV), sedative effects (associated, for example, with CBD), antipsychotic effects (associated, for example, with CBD), anti-inflammatory effects (associated, for example, with THC, CBD, CBC, CBG and CBN), anti-convulsant effects (associated, for example, with CBD and CBN), anti-biotic effects (associated, for example, with CBC, CBN and CBG), and anti-fungal effects (associated, for example, with CBC and CBG), to name a few. Under certain circumstances, there may be synergistic enhancement of certain therapeutic effects in naturally occurring cannabis when certain amounts and/or ratios of phytocannabinoids are present in combination. For example, an overall enhancement in therapeutic effects of cannabis may be achieved when a certain balance is struck between THC and CBD. For example, sedative effects of CBD may serve to oppose certain undesirable effects of THC, such as anxiety, thereby enhancing the overall therapeutic effects.
[0014] Other isolated compounds of cannabis may have certain therapeutic effects when inhaled as part of cannabis smoke, including terpenoids, flavonoids, and phytosterol. Terpenoids are derived from repeating units of isoprene (C 5 H 8 ), such as monoterpenoids (with C 10 skeletons), sesquiterpenoids (C 15 ), diterpenoids (C 20 ), and triterpenoids (C 30 ). The final structure of terpenoids can range from simple linear chains to complex molecules and may simply be a hydrocarbon, or may include alcohol, ether, aldehyde, ketone, or ester functional groups attached to a carbon skeleton. As used herein, the term terpenoids include terpenes. Over 200 naturally occurring terpenoids have been identified and isolated from cannabis. Such terpenoids include d-limonene, α-pinene, β-myrcene, linalool, pulegone, 1,8-cineole (eucalyptol), α-terpineol, terpineol-4-ol, p-cymene, borneol, Δ-3-carene, β-caryophyllene, caryophyllene oxide, nerolidol, and phytol. Some of the therapeutic effects of terpenoids include, without being bound to any theory, analgesic effects (associated, for example, with β-myrcene), sedative effects (associated, for example, with linalool, pulegone and α-terpineol), antidepressant effects (associated, for example, with linalool and d-limonene), anti-inflammatory effects (associated, for example, with β-myrcene, β-caryophyllene, 1,8-cineole, α-pinene and Δ-3-carene), anti-mutagenic effects (associated, for example, with β-myrcene and d-limonene), anti-biotic effects (associated, for example, with β-myrcene, 1,8-cineole, p-cymene, terpineol-4-ol, borneol and α-pinene), and Acetylcholinesterase (AChE) inhibitor effects (associated, for example, with pulegone, p-cymene, terpineol-4-ol and α-terpineol), to name a few. It will be appreciated that, under certain circumstances, there may be synergistic enhancement of certain therapeutic effects in naturally occurring cannabis when certain amounts and/or ratios of terpenoids are present in combination.
[0015] In addition, under certain circumstances, when phytocannabinoids and terpenoids are simultaneously present in cannabis, there may also be cross-compound synergistic effects. That is, the therapeutic effects obtained from cannabis having certain combinations of some phytocannabinoids and some terpenoids is greater than the sum of therapeutic effects obtained from the phytocannabinoids or the terpenoids taken alone. For example, without being bound to any theory, analgesic effects of THC may be synergistically boosted by various terpenoids, anticonvulsant effects of CBD and THCV may be synergistically boosted by linalool, anti-inflammatory/antifungal effects of CBC and CBG may be synergistically boosted by caryophyllene oxide, anti-inflammatory/analgesic effects of CBC may be synergistically boosted by various terpenoids, sedative effects of CBN may be synergistically boosted by β-myrcene and nerolidol, to name just few examples of synergistic effects when phytocannabinoids and terpenoids are inhaled together as part of cannabis smoke.
[0016] Naturally occurring therapeutic compounds in cannabis, including phytocannabinoids and terpenoids, are synthesized in secretory cells inside glandular trichomes of cannabis. In addition, different strains of cannabis produce and can be bred to produce varying amounts of certain compounds. For example, common “street” cannabis may have been bred such that relatively high amounts of THC are present to maximize the “high” of the person using the cannabis for recreational purposes. The same strain of “street” cannabis, however, may not have been bred to maximize, and therefore contain less than desired amounts of terpenoids or phytocannabinoids other than THC. As a result, while the effect of such cannabis strain as a euphoriant may be relatively high, their therapeutic effects may be relatively low. Therefore, to improve the therapeutic effects and to target certain therapeutic effects from cannabis, attempts to cultivate different strains of cannabis having particular combinations and amounts of specific phytocannabinoids and terpenoids have been made. However, such effort has been time consuming and not necessarily aimed at mass cultivation to serve the general public.
[0017] While some terpenoids naturally occur in cannabis, terpenoids also naturally occur in plants other than cannabis. As with cannabis, terpenoids in some plants give rise to the distinctive odor of the plants. For example, d-limonene occurs naturally in citrus plants, and is the predominant compound that gives rise to the familiar scent of citrus. Similarly, α-pinene occurs naturally in coniferous plants and is the predominant compound that gives rise to the familiar scent of pine. Thus, some terpenoids, such as d-limonene and α-pinene, occur relatively abundantly.
[0018] It has been found that the therapeutic effects of smoking herbs may be tailored by varying the terpenoid composition of the smoking herbs. In some embodiments the smoking herb may be cannabis and the therapeutic effects may include synergistic effects between the phytocannabinoids that are naturally present in a particular strain of cannabis and terpenoids that may be isolated from plants other than the particular strain of cannabis or other than cannabis in general. The terpenoids may be added to a preparation made from the particular strain of cannabis and may provide a terpenoid concentration that is just as high, if not higher, than terpenoid levels that are naturally occurring in, for example, other cannabis strains. Thus, in some embodiments, the terpenoid added to the smoking herb preparation may be at a higher concentration than that naturally found in the smoking herb or the terpenoid may not be naturally produced by the smoking herb plant at all.
[0019] It will be appreciated that adding desired types and amounts of terpenoids from plants other than the particular strain cannabis can offer several advantages. For example, terpenoids from other plants can be economically favorable compared to, for example, breeding particular strains of cannabis having similar types and amounts of terpenoids. In addition, the desired types and amounts can be targeted more specifically to enhance or magnify known therapeutic effects, or even create new therapeutic effects that may not be possible using natural or engineered strains of cannabis alone.
[0020] Reference will now be made to the drawings, in which like numerals refer to like parts throughout.
[0021] FIG. 1 is a flow chart illustrating a method 10 of preparing an herbal smoking blend, according to some embodiments. The method of preparing an herbal smoking blend comprises providing 20 a smoking herb preparation. The method additionally includes providing 30 a terpenoid solution comprising a terpenoid. The method further includes adding 40 the terpenoid solution to the smoking herb preparation.
[0022] In some embodiments, providing 20 the smoking herb preparation includes providing a smoking herb including smoking cannabis, including any species, subspecies, strain or variety of cannabis. The herb preparation can include any part of the plant of the cannabis, including the leaf, the root, the stem, the flower, or any other part of the plant that occurs naturally. In some embodiments, the smoking herb includes cannabis plants cultivated for fiber and seed production, sometimes described as low-intoxicant, non-drug, or fiber types. In some other embodiments, the smoking herb includes cannabis plants cultivated for drug production, sometimes described as high-intoxicant or drug types. In some other embodiments, the smoking herb includes cannabis plants that are escaped, hybridized, or wild forms of either of the above types.
[0023] In some embodiments, a preparation includes smoking herb that has been sufficiently dried so that it can be combusted under ordinary ambient conditions, such that the resulting smoke can be inhaled. In some embodiments, a preparation includes a smoking herb and a rolling paper that can be used to roll the smoking herb into a thin cylinder using a rolling paper, similar to a cigarette.
[0024] In other embodiments, providing 20 the smoking herb preparation can include providing a smoking herb other than cannabis. Examples of other smoking herbs include amaranthus dubius, arctostaphylos uva - ursi, argemone mexicana, arnica, artemisia vulgaris, calea zacatechichi, canavalia maritima, cecropia mexicana, cestrum nocturnum, cynoglossum virginianum, cytisus scoparius, entada rheedii, eschscholzia californica, fittonia albivenis, hippobroma longiflora, humulus japonica, humulus lupulus, lactuca virosa, laggera alata, leonotis leonurus, leonurus cardiaca, leonurus sibiricus, lobelia cardinalis, lobelia inflata, lobelia siphilitica, nepeta cataria, nicotiana (i.e., tobacco), nymphaea alba, opium poppy, passiflora incarnate, pedicularis densiflora, pedicularis groenlandica, salvia divinorum, salvia dorrii, salvia, scutellaria galericulata, scutellaria lateriflora, scutellaria nana, scutellaria, sida acuta, sida rhombifolia, silene capensis, syzygium aromaticum, tagetes lucida, tarchonanthus camphoratus, turnera diffusa, verbascum, and zornia latifolia, to name a few.
[0025] In some embodiments, providing 20 the smoking herb preparation comprises providing a smoking herb comprising at least one phytocannabinoid, such as a phytocannabinoid selected from the group consisting of delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), tetrahydrocannabivarin (THCV), cannabidivarin (SBDV) and cannabinol (CBN).
[0026] In some embodiments, providing 20 the smoking herb preparation comprises providing a smoking herb other than cannabis. In some embodiments, for example where a synergistic effect between a phytocannabinoid and terpenoids is desired, the smoking herb other than cannabis may comprise at least one added phytocannabinoid, such as a phytocannabinoid selected from the group consisting of delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), tetrahdrocannabivarin (THCV), cannabidivarin (SBDV) and cannabinol (CBN).
[0027] Still referring to FIG. 1 the illustrated method of method 10 of preparing an herbal smoking blend additionally includes providing 30 a terpenoid solution comprising a terpenoid. As used herein, a terpenoid solution refers to a mixture comprising a terpenoid and a solvent, where at least a portion of the terpenoid is incorporated in the mixture to form the terpenoid solution. The terpenoid can be miscible, immiscible, or partially miscible in the solvent. In embodiments where the terpenoid is at least partially immiscible, the resulting mixture is sometimes referred to as an emulsion.
[0028] In some embodiments, providing 30 the terpenoid solution includes providing a solution including a terpenoid selected from the group consisting of d-limonene, α-pinene, β-myrcene, linalool, pulegone, 1,8-cineole (eucalyptol), α-terpineol, terpineol-4-ol, p-cymene, borneol, Δ-3-carene, β-caryophyllene, caryophyllene oxide, nerolidol, phytol, Eugenol, Sabinene, Linalyl Acetate, Camphor, Chamazulene, beta-Farnesene, alpha-Humulene, Benzyl Benzoate, Benzyl Acetate, Geraniol, Geranyl Acetate, gamma-Terpinene, beta-Pinene, and combinations thereof.
[0029] In some embodiments, providing 30 the terpenoid solution comprises providing a terpenoid and a solvent, and mixing the terpenoid and the solvent. The solvent can include any liquid, e.g., a volatile liquid, which can incorporate a desired amount of the terpenoid in the terpenoid solution. As used herein, a liquid that incorporates the terpenoid includes a liquid that can hold the terpenoid in either dissolved form or undissolved form (e.g., suspended in the form of an emulsion). In some embodiments, a terpenoid solution having a terpenoid incorporated therein can be a solution having at least 0.1% terpenoid by volume at room temperature and atmospheric pressure.
[0030] In some embodiments, the solvent comprises an alcohol, e.g., ethanol, and water. In some embodiments, the terpenoid solution comprises about 1% to about 5% by volume of the terpenoid, about 40% to about 90% by volume of ethanol and about 10% to about 55% by volume of water. In some embodiments, the terpenoid solution comprises about 2% to about 4% by volume of the terpenoid, about 66% to about 80% by volume of ethanol and about 20% to about 30% by volume of water. Advantageously, such a solution can allow the terpenoid to be evenly distributed or suspended in the solvent, thereby facilitating the formation of a homogenous solution that allows a desire quantity of terpenoid to be added to a smoking herb preparation.
[0031] Still referring to FIG. 1 , in some embodiments, the terpenoid in the terpenoid solution can be in a substantially purified form including a targeted terpenoid selected from the group consisting of d-limonene, α-pinene, β-myrcene, linalool, pulegone, 1,8-cineole (eucalyptol), α-terpineol, terpineol-4-ol, p-cymene, borneol, Δ-3-carene, β-caryophyllene, caryophyllene oxide, nerolidol, phytol, and combinations thereof. As used herein, a substantially purified terpenoid refers to the terpenoid being free of impurities other than the targeted terpenoids, with a volume percent of the impurities not exceeding about 5%, about 1%, or about 0.1%. For example, if a substantially pure terpenoid includes a first terpenoid (e.g., d-limonene) and a second terpenoid (e.g. α-pinene) as targeted terpenoids, any other substance including other terpenoids (e.g., β-myrcene, linalool, etc.) would be considered impurities.
[0032] As described above, terpenoids can naturally originate from cannabis or other plants. In some embodiments, the terpenoid in the terpenoid solution does not naturally occur in the herb or herbs forming the smoking herb preparation. In some embodiments where the smoking herb preparation includes cannabis, providing 30 the terpenoid solution includes providing a solution including a terpenoid that is derived from a plant other than cannabis in general. In some other embodiments where the smoking herb preparation includes cannabis, providing 30 the terpenoid solution includes providing a solution including a terpenoid that is derived from a plant other than the cannabis strain from which the smoking herb has been prepared.
[0033] In some embodiments, the terpenoid in the terpenoid solution can be provided in the form of an essential oil. An essential oil, sometimes referred to as a volatile oil, an ethereal oil, or an athereola, refers to a concentrated liquid extracted from a plant that can contain, among other compounds, terpenoids. Compounds such as terpenoids included in essential oil often carry a distinctive scent, or essence (hence the name).
[0034] In some embodiments, the essential oils can be prepared using one of several methods including, without limitation, distillation, expression and solvent extraction, among others. In distillation, raw plant material, which can include the flowers, leaves, wood, bark, roots, seeds, and/or peel, is put into a distillation apparatus over water. The water is then heated above the boiling point to generate steam therefrom, which passes through the plant material. As the stem passes through the plant material, the volatile compounds are vaporized. The vapors may flow through a coil, where they condense back to liquid, which is then collected in a receiving vessel. In expression, the raw plant material is expressed mechanically or cold-pressed. Expression can be a suitable method where the raw material is available in relatively large quantities at relatively lower cost, such as orange peels for producing citrus-fruit oils. In solvent extraction, a solvent such as hexane or supercritical carbon dioxide is used to extract the oils. Solvent extraction can be a suitable method where the raw material is available in relatively small quantities at relatively higher cost, such as flowers. Solvent extraction can also be a suitable method where the chemical components are too delicate and easily denatured by the high heat used in steam distillation.
[0035] A non-exhaustive list of plant species from which essential oils can be extracted to provide a terpenoid in the method 10 of FIG. 1 include: Abies Alba, Abies Balsamea, Abies Sibirica, Achillea Millefolium, Achillea Millefolium Ligustica, Acorus Calamus, Agathophyllum Anisata, Agathophyllum Aromatica, Agathosma Betulina, Agathosma Crenulata, Allium Cepa, Allium Sativum, Aloysia Triphylla, Alpinia Galanga (L.) Sw., Alutinosum Druce, Ammi Visnaga, Amyris Balsamifera, Anethum Graveolens, Angelica Archangelica, Angelica Glauca, Aniba Rosaeodora Var. Amazonica, Anthemis Nobilis, Anthopogon Rhododendron D. Don, Apium Graveolens, Aquilaria Malaccensis, Artemisia Absinthium, Artemisia Afra, Artemisia Annua, Artemisia Dracunculus, Artemisia Pallens, Artemisia Vulgaris, Backhousia Citriodora, Boswellia Carteri, Boswellia Carterii, Boswellia Neglecta, Boswellia Serrata, Bulnesia Sarmienti, Callitris Intratropica, Cananga Odorata, Cananga Odorata Genuina, Cananga Odorata Macrophylla, Canarium Luzonicum, Carum Carvi, Cedrelopsis Grevei, Cedrus Atlantica, Cedrus Deodara, Chamaecyparis Callitropsis Nootkatensis, Chamaecyparis Lawsoniana, Chamaecyparis Obtusa Endl., Chamaemelum Nobile ( Anthemis Nobilis ), Cinnamomum Camphora, Cinnamomum Camphora L, Cinnamomum Cassia, Cinnamomum Glaucescens, Cinnamomum Polyandrum, Cinnamomum Zeylanicum, Cinnamosma Fragrans, Cistus Ladaniferus, Citrus Aurantifolia, Citrus Aurantium, Citrus Aurantium Var. Amara, Citrus Bergamia, Citrus Bergamia Risso, Citrus Clementine, Citrus Hystrix, Citrus Junos, Citrus Junos Siebold, Citrus Limonum, Citrus Paradisi, Citrus Reticulata, Citrus Sinensis, Citrus Tangerina, Coleonema Album, Commiphora Holtziana, Commiphora Myrrha, Copaifera Officinalis, Coriandrum Sativum, Cotinus Coggygria, Croton Eluteria, Cryptocarya Massoia, Cuminum Cyminum, Cupressus Rotundus, Cupressus Sempervirens, Curcuma Longa, Cymbopogon Citratus, Cymbopogon Flexuosus, Cymbopogon Flexuosus Stapf, Cymbopogon Martini Var. Martinii (Var. Motia ), Cymbopogon Nardus, Cymbopogon Winterianus Jewitt, Cymbopogon Winterianus Jowitt, Cympobogan Martini Type Sofia, Cyperus Scariosus, Daucus Carota, Elettaria Cardamomum Maton, Eremophila Mitchellii, Eriocephalus Africanus, Eriocephalus Punctulatus, Eucalyptus Citriodora, Eucalyptus Citriodora Hook., Eucalyptus Dives, Eucalyptus Globulus, Eucalyptus Polybractea, Eucalyptus Radiata, Eucalyptus Smithii, Eugenia Caryophyllata, Ferula Galbaniflua, Foeniculum Vulgare Mill Var Dulce, Foeniculum Vulgare Mill., Fokienia Hodginsil, Gaultheria Procumbens, Geranium Macrorrhizum, Helichrysum Gymnocephalum, Helichrysum Italicum, Helichrysum Stoechas, Hippophae Rhamnoides, Humulus Lupulus, Hydicum Spicatum, Hypericum Perforatum L, Hyssopus Officinalis, Illicium Verum, Juniperus Communis, Juniperus Communis L., Juniperus Oxycedrus, Juniperus Virginiana, Kaempferia Galanga L, Kunzea Ericoides, Lantana Camera, Laurus Nobilis, Lavandula Hybrida, Lavandula Latifolia, Lavandula Officinalis, Leptospermum Petersonii, Leptospermum Scoparium, Levisticum Officinalis, Lippia Citriodora, Lippia Javanica, Litsea Cubeba, Marjorana Hortensis, Matricaria Chamomilla, Matricaria Recutita, Matricaria Recutita, Melaleuca Alternifolia, Melaleuca Minor, Melaleuca Quinquenervia, Melaleuca Viridiflora, Melissa Officinalis, Mentha Arvensis, Mentha Citrata, Mentha Piperita, Mentha Pulegium, Mentha Spicata, Michelia Alba, Mix Of 4 Species, Monarda Fistulosa L., Murraya Koenigii, Myristica Fragrans, Myrocarpus Fastigiatus, Myroxylon Pereirae, Myrtus Communis, Myrtus Communis, Nardostachys Grandiflora, Nardostachys Jatamansi, Nepeta Cataria, Ocimum Basilicum, Ocimum Basilicum L., Ocimum Basillicum, Ocimum Sanctum, Ocotea Cymbarum, Oleum Abies Sibirica, Oleum Chamomille, Oleum Pinus Nigra, Oreganum Vulgare, Origanum Compactum Benth., Origanum Minutiflorum, Origanum Syriacum, Origanum Vulgare, Ormenis Mixta, Pandanus Odoratissimus, Pelargonium Graveolens, Pelargonium×Asperum, Perilla Frutescens Crispa, Petroselinum Crispum, Petroselinum Sativum, Picea Mariana, Pimenta Dioica ( Pimenta Officinalis ), Pimenta Officinalis, Pimenta Racemosa, Pimpinella Anisum, Pimpinella Anisum L., Pinus Pinaster, Pinus Pumilio, Pinus Sylvestris, Piper Cubeba, Piper Nigrum, Pistacia Lentiscus, Pogostemon Cablin, Prunus Amygdalus, Pseudotsuga Menziesii (Mirb.) Franco, Psiadia Altissima, Rhus Tarantana, Rosmarinus Officinalis, Ruta Graveolens, Salvia Lavandulifolia, Salvia Officinalis, Salvia Sclarea, Salvia Stenophylla, Santalum Album, Santalum Spicatum, Santolina Chamaecyparissus, Satureja Hortensis, Satureja Montana, Schinus Molle, Tagetes Bipinata L, Tagetes Minuta, Tanacetum Annuum Linnaeus, Tarchonanthus Camphoratus, Thuja Occidentalis, Thuja Orientalis, Thuja Plicata, Thujopsis Dolabrata, Thymbra Spicata, Thymus Capitatus, Thymus Mastichina, Thymus Satureioides, Thymus Serpillum, Thymus Vulgare, Thymus Vulgaris, Thymus Zygis, Trachyspermum Ammi, Tsuga Canadensi, Valeriana Officinalis, Vetivera Zizanioides, Vitex Agnus - Castus L, Vitis Vinifera, Xanthoxylum Armatum, Zanthoxylum Armatum Dc. (Rutaceae), Zingiber Cassumunar, Zingiber Officinale, and Zinziber Officinale, among others.
[0036] In some embodiments, examples of the the essential oil mixture includes mixtures that comprise at least one essential oil extracted from the group of plants consisting of Salvia Sclarea, Pimenta Racemosa, Pistacia Lentiscus, Citrus Limonum or a combination thereof. In some embodiments, the essential oil mixture consists essentially of Salvia Sclarea and Pimenta Racemosa. In some of other embodiments, the essential oil mixture consists essentially of Salvia Sclarea and Pistacia Lentiscus. In yet other embodiments, the essential oil mixture consists essentially of Pistacia Lentiscus and Citrus Limonum.
[0037] In some other embodiments, the essential oil mixture comprises first and second essential oils extracted from the group of plants consisting of Salvia Sclarea, Pimenta Racemosa, Pistacia Lentiscus, or Citrus Limonum, wherein a volume ratio between first and second essential oils is between about 0.01:1 and about 1:1. In some other embodiments, the volume ratio is between about 0.10:1 and about 1:1, or between about 0.50:1 and about 1:1, for instance about 1:1.
[0038] Still referring to FIG. 1 , the illustrated method 10 of preparing an herbal smoking blend further includes adding 40 the terpenoid solution to the smoking herb preparation. The terpenoid solution can be added using a suitable method for incorporating at least a portion of the terpenoid in the terpenoid solution into the smoking herb preparation.
[0039] In some embodiments, adding 40 the terpenoid solution comprises dropping the terpenoid solution on the smoking herb. As used herein, adding the terpenoid solution by dropping refers to delivering a volume of liquid using, for example, a dropper, to deliver the liquid. In some embodiments, the dropper may deliver the liquid in an amount of between about 5-100 drops per mL, depending on, among other things, the viscosity of the terpenoid solution and the type of dropper used.
[0040] In other embodiments, adding 40 the terpenoid solution comprises spraying a mist (or droplets) of the terpenoid solution on the smoking herb. As used herein, adding the terpenoid solution by spraying refers to delivering fine drops of the terpenoid solution dispersed in a gas by using, for example, a spray nozzle or atomizer, to deliver the terpenoid solution. The spray characteristics, including the spray pattern, the spray capacity, and the spray drop size depend on, among other things, the viscosity of the terpenoid solution and the type of spray nozzle used. In yet other embodiments, adding the terpenoid solution comprises spraying using an aerosol spray which includes the terpenoid solution.
[0041] In some embodiments, adding 40 the terpenoid solution comprises dipping, or at least partially immersing the smoking herb into the terpenoid solution. By way of an example, the smoking herb can be placed in a dip net or a similar device and lowered into a container containing the terpenoid solution. In some embodiments, a soaking time can be tailored to control the amount of terpenoid solution that is absorbed, impregnated, or incorporated into the smoking herb. In some embodiments, the soaking time is between about 1 second and about 1 day, or between about 10 seconds and about 1 hour, or between about 1 minute and about 10 minutes. The smoking herb can be subsequently dried in air, or by heating the smoking herb, for example at a temperature below a temperature at which the smoking herb ignites.
[0042] In some other embodiments, the smoking herb preparation comprises a smoking herb and a rolling paper. In these embodiments, adding 40 the terpenoid solution comprises adding the terpenoid solution to the rolling paper, which can subsequently be used to roll the smoking herb. The terpenoid can be added to the rolling paper using a suitable method to impregnate the rolling paper with the terpenoid solution. For example, the rolling paper can be dipped in a bath of terpenoid solution. Other methods include dropping or spraying the terpenoid solution on the rolling paper. For example, in some embodiments, the terpenoid can be added to a pre-rolled cigarette containing smoking herbs.
[0043] It will also be appreciated that the terpenoid solution can be added to the smoking herb by more than one method, for example, by two or more of the methods disclosed herein. For example, the terpenoid solution can be added to the smoking herb by dipping and drying the smoking herb preparation, and subsequently by providing drops of the terpenoid solution to the smoking herb or rolling paper for the smoking herb. In some embodiments, this can increase the concentrations of terpenoids (e.g., volatile terpenoids) in the preparation. In some other embodiments, different terpenoids solutions are added to the smoking herb preparation at different times. For example, a solution with relatively less volatile terpenoids may be added to the smoking herb concentration initially (e.g., hours before consumption, or from a manufacturer or supplier) and a solution with relatively more volatile terpenoids may be added to the smoking herb preparation immediately (e.g., minutes) before smoking.
[0044] In some embodiments where the smoking herb preparation includes cannabis, the amount of terpenoid added to the smoking herb preparation exceeds the amount of cannabis terpenoid that was present in the smoking herb prior to adding the terpenoid solution to the smoking herb preparation. In some embodiments, the amount of terpenoid added to the smoking herb preparation exceeds the amount of cannabis terpenoid that was present in the smoking herb prior to adding the terpenoid solution to the smoking herb preparation, such that the overall amount of terpenoid increases by more than about 50%, by about 100%, or by about 1000%.
[0045] In some embodiments, the amount of added terpenoid exceeds about 0.001% by weight of the smoking blend, about 0.01% by weight of the smoking blend, or about 0.05% by weight.
[0046] In some embodiments, the method 10 of preparing an herbal smoking blend further comprises subjecting the smoking herb preparation to a drying process after adding the terpenoid solution.
[0047] FIG. 2 is a schematic illustration of a smoking herb preparation system comprising according to some embodiments. The smoking herb preparation system comprises a smoking herb 80 and a terpenoid solution application kit 70 .
[0048] In some embodiments, the terpenoid solution application kit 70 comprises a terpenoid solution 62 , a terpenoid solution container 74 for holding the terpenoid solution, and a terpenoid solution applicator 72 for administering a dose of the terpenoid solution to the smoking herb.
[0049] Still referring to FIG. 2 , in some embodiments, the terpenoid solution 62 can be prepared by using a terpenoid solution preparation system 50 . The terpenoid preparation system includes a terpenoid measurement device 52 , a terpenoid mixture 54 comprising at least one terpenoid, a solvent measurement device 56 , a solvent 58 , and a terpenoid solution mixing container 60 . The terpenoid measurement device 52 can be any suitable container for measuring and mixing terpenoids to form the terpenoid mixture 54 , such as a beaker, a graduated cylinder, a measuring cup, and the like. In some embodiments, the terpenoid mixture 54 includes one or more terpenoids, such as terpenoids selected from the group consisting of d-limonene, α-pinene, β-myrcene, linalool, pulegone, 1,8-cineole (eucalyptol), α-terpineol, terpineol-4-ol, p-cymene, borneol, Δ-3-carene, β-caryophyllene, caryophyllene oxide, nerolidol, phytol, and combinations thereof. In some other embodiments, the terpenoid mixture 54 includes an essential oil mixture extracted from the group of plants consisting of Salvia Sclarea, Pimenta Racemosa, Pistacia Lentiscus, Citrus Limonum, and combinations thereof. The solvent measurement device 56 can be any suitable container for measuring and mixing different solvent components to form the solvent 58 , such as a beaker, a graduated cylinder, a measuring cup, and the like. The solvent 58 can include any liquid, e.g., a volatile liquid, which can incorporate a desired amount of the terpenoid in the terpenoid solution. In some embodiments, the solvent components include ethanol and water, in proportions described above.
[0050] In some embodiments, the terpenoid solution 62 is formed by mixing the terpenoid mixture 54 and the solvent 58 in the terpenoid solution mixing container 60 . The terpenoid solution 62 includes the terpenoid mixture 54 incorporated into the solvent 58 . In some embodiments, at least a portion of the terpenoid mixture 54 is miscible in the solvent 58 and can be dissolved in the solvent 58 to form the terpenoid solution 62 . In other embodiments, at least a portion of the terpenoid mixture 54 is immiscible in the solvent 58 and can be suspended in the solvent 58 to form the terpenoid solution 62 . The terpenoid solution 62 can then be transferred into the terpenoid solution container 74 of the terpenoid solution application kit 70 .
[0051] Still referring to FIG. 2 , the terpenoid solution application kit 70 comprises any suitable terpenoid solution applicator 72 for administering a dose of the terpenoid solution 62 to the smoking herb 80 . In some embodiments, the applicator comprises a dropper having a bulb member and a pipette member. The dropper can have any suitable design for forming suitable drops as discussed above for application on the smoking herb 80 . For example, the dropper member may have a bulb made of elastic material configured to fill the pipette member with the terpenoid solution 62 thorough a vacuum suction effect. In some embodiments, the dropper may have a threaded closure to enable long term storage of the terpenoid solution. In some embodiments, the pipette member can be graduated to guide a user to administer a predetermined dose of the terpenoid solution on the smoking herb 80 . In some other embodiments, the applicator 72 may deliver a stream of the terpenoid solution to the smoking herb 80 , rather than delivering drops. In some other embodiments, the dropper may be integrated into the container 74 itself, which may provide drops directly from an opening in the container 74 . For example, the container 74 may be dropper bottle and the dropper section may be the drop generating opening of the bottle.
[0052] FIG. 3 is a schematic illustration of a smoking herb preparation system comprising a smoking herb according to some embodiments. The smoking herb preparation system comprises a smoking herb 80 and a terpenoid solution application kit 90 . The smoking herb preparation system of FIG. 3 is similar to the smoking herb preparation system of FIG. 2 except for the terpenoid solution application kit 90 . The terpenoid solution application kit 90 comprises a terpenoid solution 62 , a terpenoid solution container 94 for holding the terpenoid solution, and a terpenoid solution applicator 92 for administering a dose of the terpenoid solution to the smoking herb. The terpenoid solution container 94 can be, for example, a plastic spray bottle made of plastic, or other terpenoid solution reservoir in fluid communication with a nozzle for dispensing the terpenoid solution, such as an atomizer that dispenses the terpenoid solution as mist or spray. The terpenoid solution 62 can be mixed in the terpenoid solution container 94 and dispensed, for example through the terpenoid solution applicator 92 , which can be a trigger sprayer, mounted on the terpenoid solution container. In some embodiments, the trigger sprayer may have a threaded closure to enable long term storage of the terpenoid solution. In some embodiments, the trigger sprayer can be configured to administer a predetermined dose of the terpenoid solution on the smoking herb 80 . The trigger sprayer 92 can also be configured to determine other spray characteristics such as droplet volume, spray angle, etc.
[0053] FIG. 4 is a schematic illustration of a smoking herb preparation system comprising a smoking herb according to some embodiments. The smoking herb preparation system comprises a smoking herb 80 and a terpenoid solution application kit 90 . While the smoking herb preparation system of FIG. 4 includes terpenoid solution application kit 90 is similar to FIG. 3 , a terpenoid solution application kit similar to the terpenoid solution application kit 70 of FIG. 4 , or any other similar application kits can be used. In addition, the smoking herb preparation system of FIG. 4 further includes a rolling sheet 100 . Unlike FIG. 2 or FIG. 3 , instead of incorporating the terpenoid solution directly into the smoking herb 80 , the smoking herb preparation system of FIG. 4 is configured such that the terpenoid solution can be incorporated into the rolling sheet 100 instead of, or in addition to, incorporating the terpenoid solution into the smoking herb 80 using the suitable terpenoid application kit 90 . In these embodiments, the resulting terpenoid rolling sheet 104 can be subsequently dried and used to roll the smoking herb 80 into a thin cylinder 110 having the smoking herb 80 rolled therein, in a similar manner to a rolled cigarette. In some embodiments, the rolling sheet 100 can be a paper made from wood pulp. In other embodiments, the rolling sheet 100 can be made from rice or other plant matter such as hemp. In some other embodiments, the rolling sheet can be a pre-formed wrapper (e.g., a cylindrical wrapper) for holding the smoking herb 80 .
[0054] Although this invention has been described in terms of certain embodiments, other embodiments that are apparent to those of ordinary skill in the art, including embodiments that do not provide all of the features and advantages set forth herein, are also within the scope of this invention. Moreover, the various embodiments described above can be combined to provide further embodiments. In addition, certain features shown in the context of one embodiment can be incorporated into other embodiments as well. Accordingly, the scope of the present invention is defined only by reference to the appended claims.
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The disclosed embodiments relate generally to herbal smoking blends and methods for preparing and using herbal smoking blends, and relate more particularly to herbal smoking blends having terpenoids added thereto. In one aspect, a method of preparing an herbal smoking blend comprises providing a smoking herb preparation. The method additionally comprises providing a terpenoid solution comprising a terpenoid. The terpenoid solution may be added to the smoking herb preparation to, for example, provide a smoking herb preparation that achieves a desired effect on a consumer of the preparation.
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RELATED APPLICATIONS
This application is a continuation of and claims priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 11/328,526, U.S. Pat. No. 7,590,665, filed Jan. 10, 2006, entitled “SYSTEM AND METHOD FOR THE SYNCHRONIZATION OF A FILE IN A CACHE”, by David Thomas et al., which in claims priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 10/033,242, U.S. Pat. No. 7,062,515, filed Dec. 28, 2001, entitled “SYSTEM AND METHOD FOR THE SYNCHRONIZATION OF A FILE IN A CACHE” by David Thomas et al., which is hereby fully incorporated by reference herein.
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to cache management and more particularly to a system and method of synchronizing a cached file with a database.
BACKGROUND OF THE INVENTION
Centralized databases are becoming increasingly popular for storing electronic files or “database assets.” Most databases are operated under a client/server computer network model. In a client/server network, a client computer requests information (e.g., makes a request for files or database assets, etc.) from a server computer. In response to the request, the server computer searches the database for the requested information, retrieves the information, and communicates the information to the requesting client computer.
Having a general repository of information such as a database is advantageous because it allows multiple users to access the same file from various client computers, thereby allowing, for example, employees from disparate departments to work together on the same project, thus promoting efficiency and teamwork. Furthermore, because employees can access the database from remote computers via a network (e.g., LAN, Internet, etc.), the employee can access and work on files from home or while “on the road.” Thus, databases help support employee mobility and even the most mobile employees can work with database assets so long as the employee can establish a network connection to a database server (e.g., the computer responsible for handling database requests).
Additionally, databases free organizations from relying on individual users to store files on local machines. Using a centralized database to store files can decrease the likelihood that a file will be lost or corrupted if an employee misplaces or damages his/her computer. Yet another advantage provided by centralized databases is that an organization can control user access to particular database assets. Through authentication and authorization (validation) processes, such as requiring user names and/or passwords, an organization can govern which employees can work with particular files. This can help in controlling of work product and in ensuring quality control.
Because database assets are typically transported over a relatively slow network connection, a cache at a user's computer can be used to increase the speed with which files can be accessed and modified. A cache typically stores a local copy of a database asset on the user's computer. Thus a user can access and modify a local copy of a file, which is generally much faster than accessing a file directly over a network. When a user makes a change to the local or “cached” file copy, the change can, as will be described below, be synchronized with the database from which the file was originally retrieved.
Despite the many advantages provided by databases, databases also present many challenges to organizations. Typically, an organization's database(s) include a myriad of different database asset types. For example, a corporation's database might include Microsoft™ Word™ files, Microsoft™ Excel™ files, WordPerfect™ files, text files, graphics files (e.g., .jpg, .tif, or .gif), html files, AutoCAD™ files, etc. In addition to storing multiple types of database assets, there may also be a number of different users trying to access the same files.
Adding to the complexity of database management, various users of database assets may prefer to use different tools (e.g., they will have a “tool of choice)” to modify different types of database assets. Thus, for example, one user may prefer to use Microsoft™ Word™ to edit word processing documents while another user may prefer a different text editor. Therefore, in managing a network incorporating a database, an organization must be able to reconcile the multifarious subjective user preferences.
Several systems have been developed in an attempt to meet the challenges presented by database management. One current system requires that users employ custom-designed tools in order to edit the assets in a database. While the custom-designed tools typically reduce latency by automatically saving changes or modifications to the database, these systems are unattractive because they do not allow a user to seamlessly employ his/her tool of choice. Instead, the user must utilize a tool provided by the database vendor or an external editor that is typically cumbersome to use. Because he/she may not be familiar or efficient with the tool, the user may require extra training and, consequently, this can result in extra expense to the employer or other organization.
A second option that is currently available allows a user to utilize standard software tools (e.g., Microsoft™ Word™) to access and modify database assets, but requires a second program (a “synchronization program”) on the client machine to synchronize any modifications that a user makes on his/her client machine with the database. These systems, also have several shortcomings. Primarily, synchronization programs are typically designed to run with only one software tool (e.g., they act as a plug-in to an existing software application) or, if designed to run with multiple programs, they require significant amounts of additional coding. Thus, a user will be able to use only the tools for which the organization has a synchronization program in place. Therefore, a user's choice in software is severely limited by the presence or absence of a synchronization program. Furthermore, these prior art systems typically require that the user take extra steps in saving data to the database. When a user saves a file on his/her local (e.g., client) machine, he/she typically must also save the file in the synchronization program in order to have the file saved to the database. While it may only take an additional few seconds to save a file to the database using the synchronization program (though it can take significantly longer, particularly to save large files to a remote database), over the course of many saves this can lead to significant losses in time and productivity. These systems are also deficient because they can lead to significant latency problems. If a user forgets to perform the extra step of saving a file to the database using the synchronization program, any modifications that the user saved using a local program or tool will only be saved locally and will not be reflected on the database until the user synchronizes the local file with the database. Thus, if a user forgets to save a file to the database using the synchronization program, the database will not contain the latest version of a file for a potentially long period of time. Consequently, if another user access the file from the database before synchronization occurs, he or she will not receive up-to-date information.
Yet another existing system for accessing and modifying database assets that has been developed is an operating system-level implementation that creates a file system on a local machine (e.g., a user's computer or client computer), that allows the user to view database assets as if the assets were locally situated. In this system, the user sees the database reflected as an additional virtual local storage device (e.g., an “E” drive). Database assets are depicted as files on the file system. When a user selects the database asset that he/she wants to edit (e.g., by double clicking on the asset), the database asset can be retrieved from the database and can be opened locally with whichever program is associated with that particular type of asset (e.g., Adobe® PhotoShop could open .jpg files). This system presents shortcomings, however, because it requires additional programming at the operating system “driver” level. Any defect or error in the program while the program is running can cause the local user's machine to cease functioning or “crash” until the operating system is reinitialized (e.g., until the client computer is rebooted), significantly reducing user productivity, and leading to loss of data.
SUMMARY OF THE INVENTION
The present invention provides a system and method of synchronizing a cache that substantially eliminates or reduces disadvantages associated with previously developed systems and methods of synchronizing caches. More particularly, embodiments of the present invention provide a system and method for bi-directional synchronization of a cache. An embodiment of the system of this invention includes a software program stored on a computer readable medium. The software programming can be executable by a computer processor to run in user space and perform steps comprising: receiving a database asset from a database; storing the database asset as a cached file in a cache; determining if the cached file has been modified; and, if the cached file has been modified, communicating the cached file to the database. In one embodiment of the present invention, the software program can determine if the cached file has been modified through automatic notification from a file management system. Alternatively, the software program can poll a cached file to determine if the cached file has changed. In another embodiment of the present invention, the software program can be further executable to perform the step of prompting an operating system to open the cached file in an application associated with the cached file's file type. In another embodiment of the present invention, the software program can be further executable to receive notifications from a database of when contention for a database asset occurs. Thus, bi-directional synchronization can occur.
Embodiments of the present invention provide a technical advantage because they do not require a user to manually save changes in a separate synchronization program, thereby saving substantial time and reducing latency.
Another technical advantage of the embodiments of the method and system of the present invention is the ability to synchronize cached files corresponding to a multitude of file types. Because various embodiments of the present invention can synchronize cached files, regardless of the file type, a user can employ his or her preferred tools of choice and he or she will not have to rely on unfamiliar, custom designed applications.
Yet another technical advantage of embodiments of the present invention is the capability to seamlessly synchronize a cache with a database. Because embodiments of the present invention can automatically determine if a cached file has been modified and can communicate the cached file to the database, latency is substantially reduced.
Embodiments of the present invention provide yet another technical advantage by being compatible with a variety of database and network architectures.
Still another technical advantage provided by embodiments of the present invention is the ability to reestablish database connections, thus increasing the likelihood that synchronization will occur.
Embodiments of the present invention provide yet another technical advantage by having the capability to receive notifications from the database when contention for a database asset occurs. Because a user can be made aware of when another user attempts to access the same database asset, issues of contention can be resolved more efficiently.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention and the advantages thereof may be acquired by referring to the following description, taken in conjunction with the accompanying drawings in which like reference numbers indicate like features and wherein:
FIG. 1 illustrates a network that can include a client computer utilizing a cache manager according to an embodiment the present invention; and
FIG. 2 is a flow chart diagramming the operation of one embodiment of the method and system for synchronization of a cache according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention are illustrated in the FIGUREs, like numerals being used to refer to like and corresponding parts of the various drawings.
The embodiments of the method and system of the present invention provide the capability to seamlessly and transparently access database files locally and synchronize cached files with a database. Embodiments of the present invention provide the ability to save a database asset as a local cached file, determine if the cached filed has been accessed or modified, and if the cached file has been accessed or modified, synchronize the cached file and the associated database (e.g., the database from which the database asset was received). Additionally, the embodiments of the present invention can also provide the ability to open, view, and/or modify database assets via a user's preferred application or software tool.
FIG. 1 illustrates a system 20 that can include a client computer 22 utilizing a cache manager 38 for managing a cache 40 according to one embodiment of the present invention. System 20 can include at least one client computer 22 and at least one server computer 24 (“Server 24 ”). Client computer 22 can connect to server 24 via a network 26 . Network 26 can comprise any global computer network (e.g., the Internet), a wireless network, a local area network, or any other network capable of transporting data between a client computer and a server. Client computer 22 can be a personal computer, a workstation, a wireless device, a laptop computer, or any other computer device operable to access data from a database. Client computer 22 can include a central processing unit (CPU) 30 connected to a computer-readable memory 32 . Memory 32 can comprise any combination of RAM, ROM, magnetic storage device, such as a hard drive, and/or other computer readable memory known in the art. Furthermore, while in FIG. 1 memory 32 is shown to be connected locally to CPU 30 at client computer 22 , memory 32 can be distributed between several devices.
Memory 32 can store a number of computer programs, including an operating system 34 , various applications 36 (that can comprise software tools) that can include word processing tools or other software tools known to those in the art, and a cache manager 38 residing in user-space. The concept of user-space is well-known to those of ordinary skill in the art. Operating system 34 can further include a file management system 35 to organize and keep track of files in memory 32 . Memory 32 can also include a cache 40 which can contain cached versions of database assets, such as cached file 42 . As will be discussed in greater detail below, cached file 42 can be a cached version, either modified or unmodified, of database asset 43 . Client computer 22 can establish network communication through a network connection device 44 . Network connection device 44 can be any network communication device that is known to those in the art.
Server 24 can include standard server computer components, including a server network connection device 46 , a CPU 48 , and a memory (primary and/or secondary) 50 . Network connection device 46 , CPU 48 , and memory 50 can be equivalent components to network connection device 44 , CPU 30 , and memory 32 of client computer 22 . Memory 50 can store database management program 52 , which can be executable to carry out standard database functions, including receiving requests for data, retrieving the data, and returning the data to the requesting computer. Memory 50 can also include a database 54 , which can include various database assets, such as database asset 43 . The database assets can include a variety of different file types, including, but not limited to, text files, spreadsheet files, graphics files, html files, etc.
It should be noted that the system architecture illustrated in FIG. 1 is by way of explanation only and is designed to give context to the embodiments of the present invention. However, various embodiments of cache manager 38 can be implemented with different architectures of client computer 22 and/or server computer 24 .
In operation, a user wishing to access database assets (e.g., database asset 43 ) can establish a connection through a standard network application, as is known to those in the art, with a server (e.g., server 24 ) associated with the database (e.g., database 54 ) on which the particular database asset (e.g., database asset 43 ) is stored. Cache manager 38 can be executable by CPU 30 to establish a connection with server 24 in any manner known in the art of establishing database connections through network connection device 44 . As is understood by those with ordinary skill in the art, access to a database typically requires authentication with the database. Therefore, the user, when initially attempting to access server 24 (and database 54 associated therewith) may be required to enter login and authentication information. As will be discussed in greater detail below, in one embodiment of the present invention, cache manager 38 can store the login and authentication information so that if the connection to server 24 is subsequently dropped or lost, cache manager 38 can re-establish the connection without requiring the user to re-enter his/her login and/or authentication information.
Once the user has established a connection to server 24 , cache manager 38 can determine the contents of database 54 and can enumerate the contents for display by a program in, for example, a graphical user interface. In one embodiment of the present invention, cache manager 38 can interface with file management system 35 for display of the database assets in a pre-existing interface. In a hierarchical file management system 35 , for example, file management system 35 will use directories to organize files into a tree structure. Thus, in the case of a hierarchical file management system 35 , cache manager 38 can interface with the hierarchical file management system 35 of operating system 34 to display database 54 as an additional tree node in the directory display and to organize database assets into the tree structure under the database directory. In the well-known Microsoft™ Windows operating system, database 54 could appear as an additional drive in a directory tree of the Windows Explorer display, and each database asset could appear as a file under the database directory. Alternatively, rather than interfacing with file management system 35 , cache manager 38 can provide an independent and/or custom graphical user interface for organizing representations of database assets.
The user can select a database asset in which he/she is interested from the graphical user interface used by cache manager 38 (e.g., either the independent graphical user interface or the graphical user interface integrated with file management system 35 ). When the user selects a database asset (e.g., database asset 43 ) by, for example, double clicking on the database asset in the Windows™ Explorer display, cache manager 38 can determine if the connection to server 24 is still established. If the connection has been lost, cache manager 38 can establish a connection to server 24 . If the connection is still established, (or once the connection is re-established), cache manager 38 can request the selected database asset (e.g., database asset 43 ). Database management program 52 will receive the request and search database 54 for database asset 43 , retrieve database asset 43 , and communicate a copy of database asset 43 to client computer 22 while typically maintaining a copy of database asset 43 on database 54 . Cache manager 38 can receive database asset 43 and store database asset 43 as cached file 42 on memory 32 . In addition, cache manager 38 can associate cached file 42 with a particular connection (e.g., with a particular database) so that if the user is accessing multiple databases, cache manager 38 can keep track of the database from which a cached file was retrieved. Cache manager 38 can also associate cached file 42 with a unique location on memory 32 . In other words, cache manager 38 can store cached file 42 in a unique location in the file system of file management system 35 .
Assume, for example, that database asset 43 is the file “myfile.jpg”. When the user requests myfile.jpg, cache manager 38 can request the file from server 24 . Database management program 52 can search database 54 for myfile.jpg, retrieve myfile.jpg, and send a copy of myfile.jpg to client computer 22 while retaining a copy on database 54 . Cache manager 38 can receive myfile.jpg and associate myfile.jpg with database 54 . Cache manager 38 can also save myfile.jpg as cached file 42 in cache 40 of memory 32 and associate myfile.jpg with a unique location in memory 32 . As an example, cache manager 38 could store myfile.jpg on a hard disk drive (e.g., in memory 32 ) as “C:\cache\db54\myfile.jpg.”
Operating system 34 can then open cached file 42 with whichever application 36 is associated with the file type for cached file 42 . For example, if cached file 42 was myfile.jpg and operating system 34 normally opened .jpg files with Adobe™ Photoshop (“PhotoShop”) (e.g., assume PhotoShop was associated with the .jpg file format), operating system 34 would open myfile.jpg with PhotoShop. The user is then free to view or modify myfile.jpg (e.g., cached file 42 ) in PhotoShop (e.g., application 36 ). As files can be opened with the application or software programs that are associated with the particular file type, a user can utilize his/her preferred tool of choice to work on a file just as if (s)he were working from a file directly from file management system 35 , providing a significant advantage over prior art systems.
After viewing and/or modifying myfile.jpg, the user can again save the file. When the user saves cached file 42 (e.g., when the user saves myfile.jpg in PhotoShop), cached file 42 can be saved in cache 40 of memory 32 at the location previously associated with cached file 42 by cache manager 38 . In other words, application 36 will save cached file 42 back to the location from which application 36 opened cached file 42 . In the case of myfile.jpg, this could entail saving myfile.jpg back to “C:\cache\db54\myfile.jpg.”
In one embodiment of the present invention, cache manager 38 can interface with file management system 35 of operating system 34 to receive notification of when a particular file (e.g., cached file 42 ) has been saved by the user. For example, when a user saves a change to myfile.jpg, file management system 35 can notify cache manager 38 that cached file 42 has been saved. Thus, if file management system 35 supports automatic notification, cache manager 38 can exploit an inherent feature of file management system 35 to determine when cached file 42 is saved. It should be noted, however, that while the file management system 35 of the Microsoft™ Windows operating system allows for notification of when a file has changed, not all operating systems do so. If file management system 35 does not support automatic notification of when files are saved, cache manager 38 can poll cached file 42 to determine if cached file 42 has been modified. One method of polling files is disclosed in U.S. patent application Ser. No. 10/034,712, entitled “Method and System for Optimizing Resources for Cache Management”, filed on Dec. 18, 2001, to inventors David Thomas and Scott Wells (the “Management Application”), which is hereby fully incorporated by reference.
Upon determining that cached file 42 has been saved, cache manager 38 can determine with which connection (e.g., with which database) cached file 42 is associated. In the continuing example of myfile.jpg, since myfile.jpg was received from database 54 , myfile.jpg is associated with database 54 , as described earlier. If the connection with which cached file 42 is associated has been dropped or lost, cache manager 38 can, in one embodiment of the present invention, re-establish the connection. This can be done by using the previously stored login and authentication information or by prompting the user to re-enter the login and/or authentication information. If the connection was not dropped or when the connection is re-established, cache manager 38 can communicate a copy of cached file 42 directly (e.g., without the use of an intermediate synchronization program) to server 24 . Because cache manager 38 can re-establish lost or dropped connections, the user can still save files back to database 54 following a dropped connection.
If, after several attempts, cache manager 38 cannot re-establish the connection, cache manager 38 can notify the user that the connection has been lost and give the user the opportunity to backup cached file 42 . Additionally cache manager 38 can delete cached file 42 so that cache 40 does not contain cached files that cannot be synchronized with a database because the connection associated with cached file 42 has been dropped.
It should be noted that even after cache manager 38 has communicated cached file 42 to server 24 , a copy of cached file 42 can remain on memory 32 of client computer 22 so that the user can continue to work on cached file 42 . Whenever cache manager 38 determines that cached file 42 has again been saved or closed in application 36 , either through notification from file management system 35 or through polling, cache manager 38 can again communicate cached file 42 to server 24 . Database management software 52 can then save cached file 42 as database asset 43 , thus synchronizing database 54 with cached filed 42 .
As can be understood from the foregoing discussion, the present invention can provide substantial advantages over previously developed systems for managing database assets. Because cache manager 38 can run in the background, a user's access to and modification of database assets can occur essentially transparently. Furthermore, because embodiments of cache manager 38 can interface with file management system 35 to receive notifications of when changes occur to cached file 42 , cache manager 38 can quickly communicate the saved changes or modifications to database 54 , thus reducing the latency between when cached file 42 is modified and when corresponding database asset 43 is updated. Also, because cache manager 38 can determine when cached file 42 has been saved, the user does not have to save cached file 42 in a separate synchronization program. Furthermore, as cache manager 38 can reside in user-space, cache manager 38 is much less likely to de-stabilize client computer 22 , as would an operating system level program. Also, cache manager 38 can be transparent to the tools or applications used to access modify cached files.
FIG. 1 illustrates a system in which there is one client computer 22 and one server 24 . However, it should be noted that there may be many client computers 22 and many servers 24 . Potentially, a single user could access multiple databases and several users could access the same database. Because many users may be attempting to access the same database, contention for the same database asset can occur. For example, while a first user is working on database asset 43 (e.g., is modifying cached file 42 ) on his/her client computer 22 , a second user could attempt to access database asset 43 from database 54 . In one embodiment of the present invention, cache manager 38 can receive notifications from database management program 52 of when additional users access database asset 43 . Cache manager 38 can then present, in a graphical user interface, various choices to the user as to how to resolve the contention over database asset 43 . For example, the first user could be given, in a dialog box, the choice to retrieve the latest version of database asset 43 with any changes made by the second user. Alternatively, database management program 52 could implement automatic rules such as giving priority to the first user, etc.
In addition to receiving notifications from database management program 52 regarding database assets upon which a user is currently working, cache manager 38 can receive notifications regarding database assets upon which the user has previously worked (e.g., database assets for which there is a corresponding cached file 42 in cache 40 ). Thus, for example, if a user has previously worked on database asset 43 and a version of cached file 42 remains in cache 40 , cache manager 38 can receive notifications regarding database asset 43 . If database asset 43 were changed by another user, cache manager 38 can receive a notification from database management program 52 regarding the change and present the notification to the user (e.g., in a graphical user interface such as a dialog box). Thus, cache manager 38 can receive information regarding various database assets (e.g., database asset 43 ) upon which a user has worked. It should be noted that database management programs 52 that provide such notifications are well known in the art.
Cache manager 38 can also receive notifications from database management system 52 that a database asset for which there is a corresponding cached file 42 in cache 40 has been deleted from database 54 . In one embodiment of the present invention, upon receipt of such notification, cache manager 38 can notify the user via a graphical user interface that the database asset has been removed and can purge the corresponding cached file 42 from cache 40 .
By having the capability to seamlessly save changes to a cached file to a database and receive notifications from the database management program regarding the associated database asset, cache manager 38 can participate in bi-directional synchronization of the cache. That is, cache manager 38 can synchronize database asset 43 with cached file 42 whenever changes are made (or detected via polling) to cached file 42 , and cache manager 38 can notify a user of changes made by others to database asset 43 . Thus, database asset 43 can reflect the most recent changes made by a user to cached file 42 and users can be made aware of changes made by others to database asset 43 .
FIG. 2 is a flow chart diagramming the operation of one embodiment of the method and system for cache synchronization of this invention. At step 60 , cache manager 38 can receive a request to establish a connection to database 54 . The request can occur, for example, in response to an employee attempting to connect to a corporate database. Cache manager 38 can establish a connection to a server associated with database 54 (e.g., server 24 ), at step 62 , via standard network communication device 44 . As would be understood by those of ordinary skill in the art, access to a database often requires that a user enter a login and/or other authentication information. To prevent the user from having to re-enter this information if the connection to server 24 is dropped or lost, cache manager 38 , at step 63 , can save the login or authentication information. Cache manager 38 , at step 64 , can provide the contents of the database (e.g., database 54 ) to an external graphical user interface. In one embodiment of the present invention, the graphical user interface can be integrated into an interface provided by file management system 35 of operating system 34 . Thus, in a Microsoft® Windows environment, database 54 could appear as an additional tree node in a directory display in the Windows Explorer file management system and each database asset associated with database 54 can appear as a file in the file tree display of the Windows® Explorer display. In an alternative embodiment of the present invention, cache manager 38 , at step 64 , can display the database contents in an independent graphical user interface. This can be done in systems where integration with operating system 34 and its associated file management system 35 cannot be easily achieved.
Based on the database assets displayed in the graphical user interface, the user can select the database asset with which he/she wishes to work (e.g., database asset 43 ). This can be done in a Windows-based environment, for example, by the user double clicking on the database asset displayed in the Windows Explorer display. At step 68 , cache manager 38 can receive a request for the selected database asset. Cache manager 38 can then determine, at step 70 , if the connection to the database with which the database asset is associated (e.g., database 54 ) is still present or whether it has been dropped or disconnected. If the connection has been dropped or disconnected, cache manager 38 , at step 71 , can re-establish the connection using either re-entered login and/or authentication information from the user or login and/or authentication information that was saved at step 63 . After the connection is re-established, or if the connection was not dropped or disconnected as determined at step 70 , cache manager 38 , at step 72 , can make a request to server 24 for the selected database asset.
At server 24 , database management program 52 can receive the request for the selected database asset (e.g., database asset 43 ), search database 54 for the database asset, and, if the database asset is found, communicate the database asset to client computer 22 . At step 76 , cache manager 38 can receive a copy of the database asset and save the copy of the database asset as cached file 42 in cache 40 of memory 32 . Additionally, at step 78 , cache manager 38 can associate the cached file 42 with a particular connection. Because cached files are associated with a particular connection, cache manager 38 will be able to communicate changes associated with a database asset (e.g., changes to the corresponding cache file) back to the appropriate (e.g., the associated) database. Cache manager 38 , at step 80 , can also associate cached file 42 with a unique location in memory 32 (e.g., at cache 40 of client computer 22 ). Thus, for example, if database asset 43 was the file myfile.jpg, cache manager 38 can save database asset 43 as cached file 42 at the location “C:\cache\db54\myfile.jpg.”
Cache manager 38 , at step 82 , can prompt operating system 34 to open cached file 42 (e.g., myfile.jpg). Operating system 34 can open cached file 42 with the application 36 with which operating system 34 (or the user) would normally open such a file. Thus, for example, if .jpg files were associated with PhotoShop, operating system 34 can open myfile.jpg with PhotoShop (e.g., application 36 ) from “C:\cache\db54\myfile.jpg.” The user can then view and/or modify cached file 42 (e.g., myfile.jpg) in the appropriate application 36 (e.g., PhotoShop).
In order to synchronize database asset 43 with cached file 42 , cache manager 38 , at step 84 , can determine if the cached file 42 has been modified. As described earlier, this can be done either through receiving notification from file management system 35 that cached file 42 has been saved or by polling cached file 42 to determine if the file has changed. As described in the Management Application, polling can be done, for example, by reading a time stamp associated with cached file 42 to determine the last time at which cached file 42 was modified. If the time stamp from the most recent polling of cached file 42 does not match the time stamp from a previous polling of cached file 42 , then cached file 42 has been modified and cache manager 38 can attempt to synchronize cached file 42 with database 54 . As can be understood by those of ordinary skill in the art, the frequency at which cache manager 38 polls cached file 42 can be adjusted to optimize the resources of client computer 22 . A more frequent polling will require more resources but will result in a lower latency between the time when a cached file 42 is modified and when cache manager 38 determines cached file 42 has been modified. Conversely, a longer time interval between each polling of cached file 42 will reduce the required resources of client computer 22 but can lead to a longer latency period. Thus, the polling interval can be set to optimize system resources with respect to latency period.
Returning now to FIG. 2 , if at step 84 cache manager 38 determines that cached file 42 has not been modified (e.g., changed, deleted, etc.), cache manager 38 can continue to either poll cached file 42 for modifications or wait for file management system 35 to indicate that cached file 42 has been modified. If, on the other hand, cache manager 38 determines at step 84 that cached file 42 has been modified (e.g., through polling or notification from file management system 35 ), cache manager 38 can determine, at step 86 , if the connection associated with cached file 42 (e.g., the connection to database 54 over which cache manager 38 received database asset 43 ) is still established. If the connection has been dropped, cache manager 38 can re-establish the connection at step 88 . If login or authentication information is required to re-establish the connection, cache manager 38 can use the login or authentication information saved from the user at step 63 or, alternatively, prompt the user to enter new login and/or authentication information. Once the connection has been re-established at step 88 (or, if at step 86 cache manager 38 determined that the connection associated with cached file 42 was still established), cache manager 38 , at step 90 , can save a copy of cached file 42 directly to database 54 (e.g., without the need for an intermediate synchronization program). Cached file 42 can then be saved as database asset 43 , and thus, database 54 can be synchronized with the most recent changes made to cached file 42 . At step 92 , cache manager 38 can optionally repeat steps 84 - 90 for cached file 42 until the user ceases work on cached file 42 or, alternatively, cached file 42 expires (some pre-determined amount of time passes during which cached file 42 is not viewed or modified).
Because cached file 42 can be communicated to database 54 immediately or almost immediately after cached file 42 has been modified, database asset 43 can more accurately reflect the latest revisions to database asset 43 . Thus, subsequent users accessing database asset 43 are ensured of having the latest revisions to database asset 43 . Furthermore, because cache manager 38 can use inherent notification features of file management system 35 or can automatically poll cached file 42 for changes, the present invention does not require the user to save cached file 42 to database 54 using a separate synchronization program, thereby further reducing latency. Additionally, by omitting the extra step of saving cached file 42 in a synchronization program, the user can save time each time he/she modifies a cached file.
The teachings of the present invention provide an additional advantage by enabling the “seamless” use of tools of choice. Because cache manager 38 can prompt operating system 34 to open cached file 42 in the application 36 with which the file type of cached file 42 is normally associated, users can use their tools of choice to modify and view database assets without having to rely on custom designed and unfamiliar tools provided by database vendors or on being limited to using only those tools for which a synchronization program exists. Additionally, because cache manager 38 resides at the file system level rather than at the operating system level (e.g., resides in user space, rather than operating space), cache manager 38 is less likely to degrade the stability of client computer 22 .
In addition to reducing latency, empowering tools of choice, and maintaining stability of client computer 22 , cache manager 38 can help resolve contention between various users for the same database asset. As can be understood by those of ordinary skill in the art, embodiments of database management software program 52 can send notification of when a user attempts to access a database asset. For example, database management software program 52 could send a notification to cache manager 38 when an additional user attempts to access a database asset 43 . Cache manager 38 can then send a notification to the first user, via a graphical user interface, that another user is attempting to access database asset 43 . In one embodiment of the present invention, this can occur whether or not the first user is currently working on cached file 42 . The first user can be given various options, such as to view the latest version of database asset 43 or, if the first user is currently modifying cached file 42 , overriding changes made by any other user to database asset 43 .
Because cache manager 38 can be notified when other users attempt to modify database asset 43 , each user who has previously accessed and modified database asset 43 can be made aware of changes to that database asset. Thus, if several members of a team are working on a project involving database asset 43 , each member can be made aware of when another member of the team (or some other user) modifies or accesses database asset 43 , thereby aiding in control of the database asset. Furthermore, cache manager 38 can provide bi-directional synchronization of database asset 43 by not only saving changes made to cached file 42 to database 54 , but also by notifying users of changes in database asset 43 .
As can be understood from the foregoing discussion, embodiments of the present invention provide a system for seamlessly and transparently synchronizing database assets as users work on those assets. Embodiments of the present invention also provide the advantage of allowing users to employ tools of choice without having to perform the extra steps required for saving a database asset through a separate synchronization program. Additionally, the teachings of the present invention enable the use of tools of choice regardless of a database asset's file type. Further, embodiments of the present invention are less likely to degrade the stability of client computer 22 .
Although the present invention has been described in detail herein with reference to the illustrative embodiments, it should be understood that the description is by way of example only and is not to be construed in a limiting sense. It is to be further understood, therefore, that numerous changes in the details of the embodiments of this invention and additional embodiments of this invention will be apparent to, and may be made by, persons of ordinary skill in the art having reference to this description. It is contemplated that all such changes and additional embodiments are within the spirit and true scope of this invention as claimed below.
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The present invention provides a system and method of synchronizing a cache that substantially eliminates or reduces disadvantages associated with previously developed systems and methods of synchronizing caches. More particularly, embodiments of the present invention provide a system and method for bi-directional synchronization of a cache. One embodiment of the system of this invention includes a software program stored on a computer readable medium. The software program can be executed by a computer processor to run in user space and perform steps comprising: receiving a database asset from a database; storing the database asset as a cached file in a cache; determining if the cached file has been modified; and if the cached file has been modified, communicate the cached file directly to the database. In one embodiment of the present invention, the software program can determine if the cached file has been modified through automatic notification from a file management system. Alternatively, the software program can poll a cached file to determine if the cached file has changed. In another embodiment of the present invention, the software program can be further executable to perform the step of prompting an operating system to open the cached file in an application associated with the cached file's file type. In yet another embodiment of the present invention, the software program can be further executable to receive notifications from a database of when contention for a database asset occurs. Thus, bi-directional synchronization can occur.
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BACKGROUND OF THE INVENTION
As is well known, a hypodermic syringe is used to inject substances into human and animal bodies. A typical hypodermic syringe comprises a barrel or body adapted to contain the substance to be injected, a hypodermic needle coupled to the barrel and means, such as a plunger, for forcing the substance from the barrel through the needle.
Hypodermic syringes, I.V. needles and the like are typically disposable and are discarded after use. One problem presented by the disposal of these devices is in shielding the sharp end of the needle so that those handling it will not be stuck. This is particularly important because, following the injection, the needle may be contaminated and spread disease, such as hepatitis and AIDS.
Typically, a hypodermic syringe is supplied with a tubular shield which is slipped over the needle from the pointed end and releasably retained on the syringe. One way to shield the needle following its use is to replace the tubular shield. Unfortunately, the passage into the shield is of small diameter and the shield must be inserted over the sharp end of the needle. Consequently, there is a substantial risk to the person attempting to do this, particularly if the reshielding is attempted during emergency periods or other times of high stress.
Other methods of needle shielding are known and are described, for example, in Bastien U.S. Pat. No. 2,571,653, Leeson et al U.S. Pat. No. 3,890,971 and Wulff U.S. Pat. No. 3,780,734. However, each of these devices suffers from various drawbacks. For example, the Bastien guarded syringe does not positively retain the guard in position, and the devices shown in the Leeson and Wulff patents are quite complex with the latter device being particularly adapted for animal usage.
Sampson et al Pat. No. 4,425,120 shows an effective way of shielding a needle. However, the device of the earlier patent requires rotational movement in order to lock the guard in the extended position. The shielded device of the later Sampson et al patent is also effective but is somewhat more complex to manufacture than is desired.
SUMMARY OF THE INVENTION
This invention provides a shielded needle apparatus which is of relatively simple construction and is easily manufactured. No modifications to the body of the injecting apparatus are required, and accordingly, the shielding features of this invention are readily adaptable to virtually any injecting apparatus, such as a hypodermic syringe, I.V. needle or the like. With this invention, only two components need to be added to a conventional injection apparatus in order to provide it with the shielding features of the invention.
According to this invention, the shielding features are provided by a collar carried by the body and a needle guard which is mounted on the body for movement relative to the body and over the collar from a retracted position in which the guard does not materially obstruct access to the point of the needle to an extended position in which the guard obstructs access to the point of the needle. The extended and retracted positions are spaced apart axially, and no rotation of the needle guard is required in moving between these positions. Means is provided for releasably retaining the needle guard in the retracted position. Also, interlocking means is provided on the needle guard and the collar, and the interlocking means is responsive to movement of the needle guard to the extended position to lock the needle guard in the extended position. Thus, by adding only a collar and the needle guard, a conventional injection apparatus can be provided with needle shielding features.
Although various different constructions are possible, the interlocking means preferably includes a groove in the collar and a projection carried by the needle guard. The projection is receivable in the groove to positively lock the needle guard in the extended position. The lock is positive in that the interlocking members are not simply held together by a biasing force or detent force which is readily overcome to allow movement of the needle guard. Rather, absent some unexpected or extraordinary force, the needle guard cannot be moved from the extended position. The projection preferably includes a shoulder and said needle guard and collar have cooperating inclined cam surfaces for facilitating the locking engagement of the shoulder and groove.
The needle guard slides over the collar in moving from the retracted position to the extended position, and the projection is also engageable with the body to reduce the relative radial movement or play between the needle guard and the body. The needle guard may have a plurality of teeth projecting generally radially inwardly to assist in guiding the needle guard in moving from the retracted position to the extended position.
Although the collar can be formed integrally with the body, preferably they are separate members, and the collar is attached to the body. To save material and to prevent the collar from prematurely restricting movement of the projection of the needle guard, the collar is preferably shorter than the needle guard and is located closely adjacent the distal end of the body. The projection carried by the needle guard is preferably closely adjacent the proximal end of the needle guard.
Although the needle guard can be releasably retained in the retracted position in different ways, preferably this is accomplished by cooperating means on the collar and the needle guard. Such cooperating means may take the form of interlocking means, and the interlocking means may include a groove on the collar and a projection on the needle guard. The projections carried by the guard for retaining the needle guard in the retracted position and for locking the needle guard in the extended position are preferably axially spaced.
The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying illustrative drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an isometric view of a hypodermic syringe embodying one form of the shielded needle apparatus of this invention, with the needle guard in the retracted position in full lines and in the extended position in dashed lines.
FIG. 2 is a longitudinal sectional view through the apparatus with the needle guard in the retracted position.
FIG. 3 is a sectional view similar to FIG. 2, with the needle guard advanced axially to the extended position.
FIG. 4 is a sectional view taken generally along line 4--4 of FIG. 2.
FIG. 5 is an enlarged fragmentary, sectional view taken generally along line 5--5 of FIG. 2.
FIG. 6 is an isometric view, partially in section, of one form of collar.
FIG. 7 is an enlarged, fragmentary sectional view of interlocking regions of the collar and needle guard in the extended position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-3 show an apparatus for injecting a substance into a human or animal in the form of a hypodermic syringe 11 which generally comprises a barrel or body 13 adapted to contain a substance to be injected, a hypodermic needle 15, a plunger 17 and a shield 19. The plunger 17 is mounted for axial sliding movement within the body 13 for forcing the substance from the body through the passage of the needle in a conventional manner.
The body 13, the needle 15, the plunger 17 and the shield 19 may be of conventional construction. Thus, the body 13, in the illustrated embodiment, is in the form of a hollow plastic cylinder having appropriate graduations or indicia (not shown) so that the amount of substance to be injected can be determined. The barrel 13 has an end wall 23 to which the needle 15 is attached in a conventional manner by a needle mounting member 24. The needle 15 is coaxial with the barrel 13 and terminates in a sharp point 25 at the distal end of the needle. The plunger 17 has a flat outer end 27 which facilitates manual movement of the plunger 17 within the barrel, and it has a piston 29 at its inner end to facilitate drawing a liquid into the body 13 or expelling the liquid from the body through the passage of the needle 15. The shield 19 is in the form of an elongated hollow cylinder which is frictionally retained on the needle mounting member 24.
The syringe 11 as described above is conventional, and the needle-shielding features of this invention are particularly adapted for use with a conventional syringe 11 of this type, as well as other substance-injecting apparati. With this invention, a collar 31 is attached to the body 13 at the distal end of the body, and a needle guard 33 is mounted on the body for movement relative to the body and over the collar from a retracted position in which the needle guard does not obstruct access to the point 25 of the needle (FIG. 2) to an extended position in which the needle guard substantially obstructs access to the point of the needle (FIG. 3).
Although various constructions are possible, the collar 31 in the embodiment illustrated is in the form of an axially short, generally cylindrical and tubular, molded plastic member which completely surrounds a distal region of the body 13 and which has a generally cylindrical axial passage 34 extending through it. The collar 31 has an outwardly opening, annular groove 35 in a central region of its outer surface and an annular groove 37 closely adjacent its proximal end. The groove 37 is formed by a conical surface 39 and an annular shoulder 40. The collar 31 is optionally provided with an annular flange 41 at its distal end which projects radially inwardly for engagement with the distal end of the body 13 as shown in FIGS. 2 and 3. The collar 31 has an exterior conical cam surface 42 which slopes radially outwardly as it extends distally and which terminates at the groove 37 to facilitate locking the needle guard 33 in the extended position.
The needle guard 33 in the embodiment illustrated is in the form of an elongated, generally cylindrical plastic sleeve. The needle guard 33 has an annular rib or projection 43 adjacent its distal end, and a pair of diametrically opposed, radially inwardly extending teeth 45 at its proximal end. The opposite ends of the needle guard 33 are open.
Although various constructions are possible, the needle guard 33 has a generally cylindrical passage 51 extending completely through it and a conical cam surface 53 (FIG. 5) near the proximal end of the needle guard. The conical cam surface 53 tapers slightly radially inwardly as it extends proximally and terminates in a projection which includes an annular shoulder 55 (FIG. 5) which is spaced slightly distally from the teeth 45. The conical cam surface 53 and the shoulder 55 may be interrupted by grooves 57 (only one being shown in FIG. 5) leading to each of the teeth 45.
To assemble the collar 31 and the needle guard 33, the needle guard may be placed on the collar as shown in FIG. 2 to form a subassembly, and the subassembly positioned over the body 13 also as shown in FIG. 2. The collar 31 is then attached to the body 13 as by sonic welding or an adhesive.
The syringe 11 may be shipped and stored with the needle guard 33 in the retracted position of FIG. 2 and with the shield 19 protecting the user from injury against the needle 15. In the retracted position, the rib 43 on the interior surface of the needle guard 33 is seated in the annular groove 35 of the collar 31. However, because of the rounded nature of the groove 35 and the rib 43 and because of the relatively shallow depth of the groove, the needle guard 33 is only releasably retained in the retracted position. In other words, it is relatively easy for the user to manually move the needle guard 33 from the retracted position to the extended position.
Prior to use, the shield 19 is removed, and the syringe 11 is used in the usual manner to withdraw medication from a drug vial and to inject that medication into a patient. Following this, the needle guard 33 is manually grasped and removed from the retracted position of FIG. 2 to the extended position of FIG. 3.
To reach the extended position, the user slides the needle guard 33 distally and forces the conical surface 53 over the conical surface 42 at the proximal end portion of the collar 31 and into the groove 37 (FIGS. 3 and 7). The conical surface 42 facilitates the movement of the conical surface 53 over the proximal end portion of the collar 31 so that the shoulder 55 may snap into the groove 37. During the axial sliding movement of the needle guard 33 from the retracted position toward the extended position, the teeth 45 slide along, or are in slightly spaced relationship with, the outer surface of the body 13 to thereby support the proximal end of the needle guard in its sliding movement along the body. The collar serves as a bearing to support regions of the needle guard 33 which are distal to the teeth 45 in the advancing movement of the needle guard toward the extended position. In other words, the teeth 45 and the outer surface of the body 13 form a proximal bearing, and the collar 31 and the surface of the passage 51 form a distal bearing for the needle guard 33.
The shoulders 40 and 55 are preferably flat and radially extending as shown in FIG. 3 so that retrograde movement of the needle guard 33 from the extended position back to the retracted position will not occur in normal disposal of the used syringe absent unexpected or unusual forces on the needle guard. Because the teeth 45 and the region of the needle guard 33 are relatively rigid, it is also extremely difficult to advance the needle guard proximally of the position shown in FIG. 3. However, if this should occur, the groove 35 serves as a safety groove or backup to catch the teeth 45 to prevent movement of the needle guard 33 completely off of the body 13.
Although an exemplary embodiment of the invention has been shown and described, many changes, modifications and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.
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An apparatus for injecting a substance into a human or animal comprising a body, a needle coupled to the body and terminating in a point and a needle guard mounted on the body for movement from a retracted position in which the guard does not shield the needle to an extended position in which the guard shields the needle. The needle guard can be releasably retained in the retracted position and locked in the extended position. Locking of the needle guard is accomplished by interlocking members carried by the needle guard and by a collar mounted on the body.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority from U.S. Provisional Patent Application Ser. No. 61/325,612 filed on Apr. 19, 2010, the entirety of which is expressly incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to food processing vats and, more particularly, to vents that are used with food processing vats.
[0004] 2. Discussion of the Related Art
[0005] Vents that are mounted to food processing vats are known in the food processing industries. Such vents fluidly connect an inside space within the vat to the ambient.
[0006] Clean-in-place systems for use with food processing vats are also known in the food processing industries. Such clean-in-place systems automatically spray cleaning fluid, in liquid form, inside of food processing vats.
SUMMARY OF THE INVENTION
[0007] The inventors have recognized that in typical food processing vats, the clean-in-place systems have been primarily designed to clean the inside walls of the vat and large mechanicals that are housed in the vat, such as agitator shafts, while other parts of the overall vat systems have not been cleaned with these clean-in-place systems. The inventors have also recognized that in typical food processing vats, vents must be manually cleaned by technicians and, at times, require removal of the vents for thorough cleaning, which can be substantially time consuming. The inventors have further recognized that typical vents have side walls with relatively small surface areas upon which to condense out water or other condensate from the vapor or vented fluid that flows out of the vat. The present invention contemplates a vent for a food processing vat that addresses these and other problems and drawbacks of the prior art.
[0008] In accordance with an aspect of the invention, a food processing vat system is provided with a vent that is attached to a vat and fluidly connects an inside space of the vat to the ambient so as to maintain a pressure within the vat at an ambient pressure and/or to direct a vented fluid that flows out of the vat to the ambient. A nozzle that is configured to convey a cleaning fluid through it is mounted to at least one of the vent and the vat, and may be mounted in a generally fixed position. The nozzle has an opening that is positioned with respect to the vent so that the nozzle directs the cleaning fluid into the vent while the vent remains attached to the vat. This allows the vent to be cleaned in place, without requiring manual cleaning by a technician.
[0009] In accordance with another aspect of the invention, the nozzle is positioned inside of the vent. The vent may define a vent body having an upper edge and the nozzle may be positioned below the upper edge of the vent body. The vent may include a lid, and the vent may further include a nozzle tube that extends through the lid and holds the nozzle inside of the vent. This may also allow the vent to be cleaned in place, without requiring manual cleaning by a technician.
[0010] In accordance with another aspect of the invention, the vent defines a vent body and a lid that is positioned with respect to the vent body such that (i) vented fluid that flows out of the vat can flow between the vent body and the lid so that the vented fluid can exit the vent, and (ii) cleaning fluid that is delivered out of the nozzle cannot flow between the vent body and the lid so that the cleaning fluid remains in the vent body or flows into the vat. The lid may include a lid lower portion that longitudinally overlaps at least part of an upper end of the vent body and is transversely spaced from the upper end of the vent body. A lid upper portion may be spaced from the upper end of the vent body. The lid may be maintained by spring clips in such a position with respect to the vent body. This may allow the vented fluid that flows out of the vat to be directed to the ambient while maintaining any cleaning fluid that is sprayed in the vent to remain in the vent or flow into the vat.
[0011] In accordance with another aspect of the invention, the vent further includes a collar that is positioned with respect to the nozzle and the lid so that the cleaning fluid that is delivered out of the nozzle is deflected by the collar to prevent the cleaning fluid from exiting the vent. The collar may be connected to and extend downwardly from a lower surface of the lid, spaced radially inside of an outer perimeter of the lid. The vent body may include a tube that is housed concentrically inside of a canister, and the collar may be concentrically aligned between the tube and container. This may allow the collar to deflect cleaning fluid that is delivered from the nozzle so that the cleaning fluid remains in the vent body or flows into the vat, without spraying outside of the vent.
[0012] In accordance with another aspect of the invention, the vent is removably attached to the vat. The vent may be attached to the vat with a clamp that holds a pair of flanges that are provided at respective ends of the vent tube, and a vat tube that is fixed to the vat. This may permit quick removal of the vent from the vat for occasional servicing and maintenance.
[0013] In accordance with another aspect of the invention, the vent tube extends between the vat or vat tube and the lid of the vent, directing the vented fluid from the vat to the vent. A lower portion of the vent tube may extend beyond the canister and define a solid side wall. An upper portion of the vent tube may be provided within the canister and may have a perforated side wall. The openings or perforations of the perforated side wall may be configured to diffuse streams of the cleaning fluid that is delivered by the nozzle, so that the cleaning fluid is spread out and applied to substantially an entire inner surface(s) area of the vent. This may allow a nozzle to be used near the walls of the vent while delivering cleaning fluid across substantially the entire walls of the vent.
[0014] In accordance with another aspect of the invention, the canister extends concentrically around the vent tube so as to define an annular passage between the vent tube and the canister and through which the vented fluid can flow. The canister may further include a lower wall that extends generally radially toward and connects to the vent tube. The lower wall of the canister may connect to the vent tube at a location on the vent tube that generally defines a division line between the solid side wall of the vent tube and the perforated side wall of the vent tube. This may allow the cleaning fluid to be diffused through the perforated side wall of the vent tube, spreading out its application through the vent, while retaining the cleaning fluid within the vent or allowing it to flow into the vat.
[0015] According to another aspect of the invention, the canister lower wall is slanted so that different depths of the annular passage are defined at different locations about a periphery of the vent tube. The slanted lower wall may extend angularly with respect to the canister side wall so that corresponding portions of the slanted lower wall, vent tube, and canister side wall define a collection chamber that can collect condensate that condenses out of the vented fluid. The collection chamber may also collect the cleaning fluid that remains in the vent and does not flow into the vat. The vent may include a drain that extends through the canister side wall at a location that corresponds to a deepest portion of the annular passage. This may allow removal of condensate, including water and non-water materials that may be suspended in the vented fluid, the cleaning fluid, and/or other substances that may collect in the collection chamber to be removed from the vent.
[0016] Various other features, objects, and advantages of the invention will be made apparent from the following description taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The drawings illustrate the best mode presently contemplated of carrying out the invention.
[0018] In the drawings:
[0019] FIG. 1 is an isometric view from above and in front of a vat system incorporating a clean-in-place vent in accordance with the present invention;
[0020] FIG. 2 is an isometric view from above and in back of the vat system of FIG. 1 ;
[0021] FIG. 3 is a top plan view of the vat system of FIG. 1 ;
[0022] FIG. 4 is a front elevation view of the vat system of FIG. 1 ;
[0023] FIG. 5 is a sectional view of the vent of the vat system of FIG. 1 , taken at line 5 - 5 of FIG. 4 ; and
[0024] FIG. 6 is a sectional view of the vent of the vat system of FIG. 1 , taken at line 6 - 6 of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIGS. 1 and 2 illustrate a vat system 5 that can be used for processing food and related products (collectively referred to as “vat contents”) by mechanically manipulating and heating or cooling the vat contents, depending on the particular food or related product being processed. In a representative application, the vat system 5 may be used in the production of cheese, although it is understood that the vat system 5 may be used in processing other types of food products. The vat system 5 includes a vat 7 that has an agitation system 40 which performs the mechanical manipulation tasks by rotating a pair of shafts upon which blade assemblies are mounted, and a zoned heat transfer system 50 to perform heating and/or cooling to provide zoned temperature control to the vat 7 .
[0026] Vat 7 defines an enclosure having a top wall 10 , a bottom wall 11 , and side walls 14 , 15 , all of which extend longitudinally between a pair of end walls 18 and 19 . The walls 10 , 11 , 14 , 15 , 18 , 19 are multilayered, having an outer jacket 20 and an inner shell 25 that are spaced from each other. Insulation and various components of the zoned heat transfer system 50 are housed between the jacket 20 and shell 25 . The shell 25 is the innermost structure of the vat 7 , so that its inner surface surrounds and defines an outer periphery of a void or inside space 8 within the vat 7 . A lower part of the inside space 8 resembles two horizontal parallel cylinders that transversely intersect each other, being defined by a lower portion of the shell 25 that has a pair of arcuate depressions which extend along the length of the vat 7 , on opposing sides of a longitudinally extending raised middle segment. From the lower portion of the shell 25 , opposing side portions extend in an outwardly bowed manner, arching away from each other in a transverse direction of the vat 7 . An upper portion of the shell 25 arcs gradually between side portions of the shell 25 and defines an upper perimeter of the inside space 8 of vat 7 .
[0027] Referring now to FIGS. 1-4 , operation of the zoned heat transfer system 50 alters the temperature of the inside space 8 of vat 7 , which correspondingly changes a volume of the gases within the inside space 8 of vat 7 . Vent 60 allows the vat 7 to breathe, accommodating the changing volume of gases without changing a pressure within the vat 7 so as to keep the pressure of the inside space 8 of the vat at the ambient pressure.
[0028] Referring now to FIGS. 5 and 6 , vent 60 includes a vent body 62 that is defined by a vent tube 70 and a container or canister 80 , and a lid 100 that sits over the vent body 62 . A nozzle 90 that sprays a cleaning fluid, which may be in a liquid form, is positioned with respect to the vent tube 70 , canister 80 , and lid 100 so that the cleaning fluid that exits the nozzle 90 either remains in the vent 60 or flows into the vat 7 , described in greater detail elsewhere herein.
[0029] Still referring to FIGS. 5 and 6 , in this embodiment, the vent 60 is attached to the vat 7 by coupling the vent tube 70 to a vat tube 55 . Vat tube 55 is connected at its bottom end to the top wall 10 of the vat 7 . A flange 56 is connected to the top end of the vat tube 55 . Flange 56 sits below a cooperating flange 71 that is connected to the bottom of vent tube 70 , and a seal 58 sits between the flanges 56 , 71 of the vat and vent tubes 55 , 70 , respectively. A lower surface of flange 56 and an upper surface of flange 71 are angled toward each other. Correspondingly, a cross-sectional profile shape of the flanges 56 , 71 together is wedge-shaped, tapering down from a thicker portion adjacent the vat and vent tubes 55 , 70 , respectively, to a thinner portion that is radially furthest from the vat and vent tubes 55 , 70 , respectively. A clamp 57 ( FIG. 5 ) fits around and engages both of the flanges 56 , 71 and pushes them toward each other to compress the seal 58 to provide a liquid-tight joint between the vat and vent tubes 55 , 70 , respectively. Removal of the clamp 57 from the flanges 56 , 71 allows the vent 60 to be detached from the vat 7 by lifting the vent away from the vat tube 55 .
[0030] Still referring to FIGS. 5 and 6 , in this embodiment, a lower portion 72 of the vent tube 70 extends upwardly from the flange 71 , toward the canister 80 . Lower portion 72 has a solid side wall 73 which ensures that the vented fluid flows in a generally longitudinal direction through the lower portion 72 , without escaping the confines of the lower portion 72 of the vent tube 70 .
[0031] An upper portion 75 of the vent tube 70 connects to and extends upwardly from the lower portion 72 . The upper portion 75 in this embodiment has a length that is over half of the overall length of the vent tube 70 , the upper portion 75 being about four times longer than the lower portion 72 . In another embodiment, the upper portion 75 may be about two times longer than the lower portion 72 . A side wall 76 of upper portion 75 is perforated with openings 77 that extend entirely through the thickness of the side wall 76 and that are spaced at substantially equal distances from each other to provide a matrix or array of openings 77 that define the perforation(s).
[0032] The perforated side wall 76 of the upper portion 75 of the vent tube 70 allows the vented fluid that flows out of the lower portion 72 to flow in both a generally longitudinal direction through the upper portion 75 and also in a generally radial direction out of the openings 77 . In so doing, a portion of the vented fluid flows through the entire length of the upper portion 75 and exits out of the vent tube 70 through an opening defined at an upper perimeter edge of the upper portion 75 with its further longitudinal flow being impeded by the overlying lid 100 . The rest of the vented fluid diffuses and radially flows through the openings 77 of the perforated side wall, with its further radially directed flow being impeded by the canister 80 .
[0033] Still referring to FIGS. 5 and 6 , canister 80 includes a solid side wall 81 that extends concentrically around the vent tube 70 , so as to define an annular passage 78 between the vent tube 70 and the canister 80 . The annular passage 78 provides a path through which the vented fluid flows in a longitudinal direction while exiting the vent 60 , after flowing in the radial direction into the annular passage 78 from the vent tube 70 . A diameter of the flow path through the vent 60 which is defined by the solid side wall segments that radially restrict flow through the vent 60 , namely, the side walls 73 and 81 , has a step-change increase in which the relatively smaller diameter of the side wall 73 of the vent tube lower portion 72 increases to a relatively larger diameter of the side wall 81 of the canister 80 . Such diameter increase occurs generally at a lower wall 82 of the canister 80 .
[0034] Lower wall 82 of the canister 80 has an annular perimeter shape and extends radially between the vent tube 70 and canister side wall 81 . Lower wall 82 connects the canister side wall 81 to the vent tube 70 at a location that generally defines a division line between the solid and perforated side walls 73 , 76 , respectively, of the upper and lower portions 72 , 75 , respectively, of the vent tube 70 .
[0035] In this embodiment, the canister lower wall 82 is slanted, extending angularly with respect to the tube and canister side walls 73 , 76 , 81 . This provides the annular passage 78 with different depths at different locations about the perimeter of the vent tube 70 . A collection chamber 85 is defined by a space between respective portions of the slanted lower wall 82 , vent tube 70 , and canister side wall 81 that can collect condensate that condenses out of the vented fluid and/or cleaning fluid that is delivered out of nozzle 90 .
[0036] The particular volume of condensate, cleaning fluid, or other liquid that the collection chamber 85 holds is determined at least in part by (i) the width of the lower wall 82 and thus the radial distance between the vent tube 70 and canister 80 , and (ii) the particular location of the division line between the solid and perforated side walls 73 , 76 , respectively, of the upper and lower portions 72 , 75 , respectively, of the vent tube 70 and thus a maximum height at which contents in the collection chamber 85 can be held and over which the contents will spill through the openings 77 of the perforated side wall 76 and run down the inside of vent tube 70 and into the vat 7 . In this embodiment, the diameter of the canister 80 is about 25 percent larger than the diameter of the vent tube 70 , although it is understood that any other satisfactory differential may be employed. Also in this embodiment, the division line between the solid and perforated side walls 73 , 76 , respectively, of the upper and lower portions 72 , 75 , respectively, of the vent tube 70 extends orthogonally with respect to a longitudinal axis of the vent tube 70 , whereby the division line is not slanted like the orientation of the canister lower wall 82 . In another embodiment, the division line between the solid and perforated side walls 73 , 76 , respectively, of the upper and lower portions 72 , 75 , respectively, of the vent tube 70 may extend parallel to the canister lower wall 82 .
[0037] Still referring to FIGS. 5 and 6 , regardless of the particular location of the division line between the solid and perforated side walls 73 , 76 , respectively, of the upper and lower portions 72 , 75 , respectively, of the vent tube 70 , the collection chamber 85 includes a drain 87 that extends though the canister side wall 81 . The drain 87 of this embodiment is provided at a location upon the canister side wall 81 that corresponds to a deepest portion of the annular passage 78 and thus at the bottom of the collection chamber 85 . The drain 87 allows removal of condensate, including liquid and non-liquid materials that may be suspended in the vented fluid, the cleaning fluid, and/or other substances that may collect in the collection chamber 85 , to be removed from the vent 60 . Still referring to FIGS. 5 and 6 , the cleaning fluid that may collect in the collection chamber 85 is that which is delivered from nozzle 90 during a clean-in-place procedure. Nozzle 90 is positioned with respect to the vat system 5 so that its opening(s) 91 directs cleaning fluid into the vent 60 while the vent remains attached to the vat 7 . FIG. 6 shows another nozzle 90 that is mounted to the top wall 10 of the vat and has openings 91 provided about its outer surface so as to direct cleaning fluid in multiple directions, so that some of the cleaning fluid may enter the bottom opening of the vat tube 55 and may deflect into the vent 60 .
[0038] Still referring to FIGS. 5 and 6 , in this embodiment, toward the top of the vent 60 , one of the nozzles 90 that can spray cleaning fluid is mounted fully inside of the vent 60 . This nozzle 90 is positioned below an upper edge of the vent body 62 and is substantially aligned with a longitudinal axis of the vent 60 and thus concentrically inside of the perforated side wall 76 of the upper portion 75 of vent tube 70 . With the nozzle 90 mounted in this position with respect to the perforated side wall 76 , the discrete streams of cleaning fluid leaving the openings 91 can be split into more streams that deflect in different directions while being sprayed through the openings 77 of the perforated side wall 76 , diffusing the cleaning fluid and spreading out its application through the vent 60 .
[0039] Referring now to FIG. 6 , in this embodiment, the nozzle 90 is mounted to and suspended from the lid 100 with a nozzle tube 92 . The nozzle tube 92 extends through a flange that is raised above the rest of the lid 100 with a tube segment that extends above and below the lid 100 . An end of the nozzle tube 92 that is outside of the vent 60 has a flange that couples to a corresponding flange of a cleaning fluid supply line 95 , allowing such flanges to be uncoupled from each other to separate the nozzle tube 92 from the cleaning fluid supply line 95 while leaving the nozzle tube 92 connected to the lid 100 . The cleaning fluid supply line 95 is connected to a known clean-in-place system (including suitable plumbing components, hardware components, and controls) that is configured to deliver cleaning fluid for automatically spraying down predetermined surfaces within the vat system 5 .
[0040] Referring again to FIGS. 5 and 6 , the lid 100 is dished out, presenting a convex upper surface and a concave lower surface, with a lower lip 102 provided at a lower portion 105 of the lid 100 and extending downwardly from its outer perimeter. The lid 100 is positioned with respect to the vent body 62 such that (i) vented fluid that flows out of the vat 7 can flow between the vent body 62 and the lid 100 so that the vented fluid can exit the vent 60 , and (ii) cleaning fluid that is delivered out of the nozzle 90 cannot flow between the vent body 62 and the lid 100 so that the cleaning fluid remains in the vent body 62 or flows into the vat 7 . The lip 102 of the lower portion 105 longitudinally overlaps at least part of an upper end of the vent body 62 and is transversely spaced from the upper end of the vent body 62 . A lid upper portion 110 is spaced longitudinally from the upper end of the vent body 62 .
[0041] The lid 100 of this embodiment is maintained in this overlying and longitudinally and radially-spaced relationship with respect to the vent body 62 by spring clips 120 . In this embodiment, the spring clips 120 are connected to and extend upwardly from an upper edge of the vent tube 70 . Spring clips 120 are bent and generally L-shaped and have an upright segment that aligns with the vent tube 70 and a horizontal segment that engages an inner circumferential surface of a collar 125 .
[0042] Still referring to FIGS. 5 and 6 , collar 125 is connected to and extends down from a lower surface of the lid 100 and is spaced radially inside of an outer perimeter of the lid 100 . The collar 125 is positioned concentrically between the vent tube 70 and canister 80 when viewed from a top plan view. In this embodiment, the collar 125 extends downwardly from the lid 100 to a height along the vent 60 at which upper edges of the vent tube 70 and canister 80 are provided. In another embodiment, the collar 125 extends relatively further down, between the vent tube 70 and canister 80 , and thus into the annular passage 78 . Regardless of how far the collar 125 extends from the lid 100 in any particular embodiment, the collar 125 is positioned with respect to the nozzle 90 and the lid 100 so that some of the cleaning fluid that is delivered out of the nozzle 90 is deflected by the collar 125 into the annular passage 78 , preventing such cleaning fluid from exiting the vent 60 . The collar 125 thus cooperates with the upper end of vent tube 70 and the upper end of canister 80 to define a serpentine path between the interior of the vent tube 70 and the exterior of canister 80 , which allows passage of air into and out of vat 7 and also functions to ensure that cleaning fluid from nozzle 90 does not escape from vent 60 other than through collection chamber 85 at the lower end of annular passage 78 .
[0043] Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.
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A food processing vat is provided with a vent that can be automatically cleaned in place, without requiring manual cleaning by a technician or removal of the vent from the vat. A nozzle is mounted to at least one of the vent and the vat and has an opening(s) that is posited with respect to the vent to direct cleaning fluid into the vent. The vent may include a canister that concentrically surrounds at least a portion of a vent tube that is fluidly connected to the vat, which collects cleaning fluid and/or condensate from gas that enters or exits the vat.
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[0001] This application claims priority based on request GB1409085.6 filed 21/05/2014
FIELD OF THE INVENTION
[0002] The present invention relates generally to drug therapy but more particularly to the use of argon as a mu opioid receptor antagonist.
BACKGROUND OF THE INVENTION
[0003] The mu receptor is a major subclass of the opioid receptors. The mu receptor exists either at the pre- and/or post-synaptic level depending upon the body regions and cell types where it is expressed. In the brain, the mu receptor is highly expressed in various brain regions and areas such as the cortex, the thalamus, the olfactory bulb, the amygdala, the nucleus accumbens, the striatal complex including the caudate nucleus and the putamen, the solitary tract nuclei, the rostral ventromedial medulla, and the periaqueductal gray region. The mu receptor is also highly expressed in other body regions such as the spinal cord, the peripheral sensory neurons, and the intestinal tract.
[0004] Activation of the mu receptor is known to be instrumental in various diseases, but as many pharmaceutically active compounds, mu receptor antagonists produce side effects. By way of example, the well-known mu receptor antagonist naltrexone may cause liver damage. Because of this, it carries an FDA boxed warning for this side effect and its use by persons with acute hepatitis or liver failure. By another way of example, the other well-known mu receptor antagonist naloxone may cause irregular heartbeats, chest pain, short breathing, wheezing, dry cough, severe nausea or vomiting, severe headache, agitation, and confusion.
SUMMARY OF THE INVENTION
[0005] In view of the foregoing disadvantages inherent in the known devices now present in the prior art, the present invention, which will be described subsequently in greater detail, is to provide objects and advantages which are:
[0006] To provide a mu receptor antagonist with additional inhibitory action at the vesicular monoamine transporter inhibitor, and its use in the treatment of pathological conditions in a mammal in need thereof.
[0007] In order to do so, the invention consists in the use of argon as a mu receptor antagonist with additional inhibitory action at the vesicular monoamine transporter, and with no or minimal side effects, for general pharmaceutical use.
[0008] 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 additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended heret
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 Inhibition of the binding of DAMGO, a mu opioid receptor agonist, by argon in membrane protein preparations. Compared to 100 vol % nitrogen (controls), 100 vol % argon altered the binding of DAMGO by decreasing B max (number of receptors) by 15% and producing a trend toward reduction of 1/K d (affinity), conditions that resulted in a 60% decrease in mu receptor activity (B max ×1/k d ). These data demonstrate that argon has antagonistic properties at the mu opioid receptor. *P<0.05.
[0010] FIG. 2 Effects of argon on the increase in carrier-mediated dopamine release and the reduction in KCl-evoked dopamine release induced by amphetamine in brain slices taken from the rat nucleus accumbens. (A) Experimental recording of the effect of amphetamine on carrier-mediated and KCl-evoked dopamine release. (B) The addition of amphetamine in the presence of air (control experiments) resulted in an increase in carrier-mediated dopamine release (b) compared to sham slices treated with saline solution and air (a). The addition of argon instead of air in the amphetamine solution led to a reduction of the facilitating action of amphetamine (c) as compared to control experiments performed with amphetamine and air (b). (C) The addition of amphetamine in the presence of air (control experiments) resulted in a decrease of Peak 3 (P3) KCl-evoked dopamine release (b) as compared to sham slices treated with saline solution and air (a). The addition of argon instead of air in the amphetamine solution led to an increase of the inhibiting action of amphetamine on KCl-evoked dopamine release (c) as compared to control experiments performed with amphetamine and air (b). (B-C) These data taken together indicate that argon has inhibitory properties at the type 2 vesicular monoamine transporter (see main text above). *P<0.02.
[0011] FIG. 3 Effect of argon on locomotor activity in spontaneously hypertensive rats, known to be a model for the attention deficit and hyperactivity disorder (ADHD). Spontaneously hypertensive rats treated with argon (Ar) had a lower locomotor activity than rats treated with medical air (Air). This indicates that argon reduces locomotor hyperactivity in spontaneously hypertensive rats. *P<0.02.
[0012] FIG. 4 Effects of argon on stress-induced behaviors in Sprague-Dawley rats. (A). Rats treated with argon (Ar) had a reduced number of righting reflex when handled abdomen side up compared to control animals treated with medical air (Air). (B) Rats treated with argon (Ar) had an increased number of social interactions compared to control animals treated with medical air (Air). Alternatively, in the second series of experiments, rats treated with argon (Ar) penetrated the central area of the open field to a greater extent than did control animals treated with medical air (Air), thereby indicating that argon-treated rats had reduced level of fear and anxiety. These data demonstrate that argon decreases the stress and anxiety responses induced by stressful conditions. *P<0.05.
DETAILED DESCRIPTION
[0013] The term ‘antagonist’ and ‘inhibitory action’ are used in their normal sense in the art, i.e. a chemical compound that reduces the activity of a protein triggering a response.
[0014] Argon equilibrates rapidly within the brain by diffusing across the blood brain barrier. Argon at a pressure of around 15 atmospheres absolute acts as an agonist of the type A γ-aminobutyric acid (GABA) and benzodiazepine receptors (Abraini J. H. et al., Anesth. Analg ., 2003). However, because these experiments were performed at unusual elevated concentrations, it remains uncertain whether argon would exhibit similar pharmacological properties at normal atmospheric pressure. Instead, here we show that argon at normal atmospheric pressure is a mu opioid receptor antagonist with additional inhibitory action at the vesicular monoamine transporter. Since the mechanisms of action of argon are still unknown, these pharmacological properties could likely be instrumental in the beneficial effects of this inert gas in animal models of heart attack, traumatic brain injury, acute ischemic stroke, and sensitization (addiction) to psychostimulant drugs such as amphetamine and its derivatives [Pagel P. S. et al., Anesth. Analg ., 2007; Jawad N. et al., Neurosci. Lett ., 2009; Loetscher P. D. et al., Crit. Care , 2009; David H. N. et al., PlosOne , 2012; Zhuang L. et al., Crit. Care Med., 2012; Brücken A. et al., Brit. J. Anaesth ., 2013; David H. N. et al., Med. Gas. Res . 2014 , Transl. Psych., 2015].
[0015] Unlike many other agents with antagonistic properties at the mu opioid receptor, argon is rapidly eliminated from the body through respiration, is chemically and metabolically inert, and so far as today has no reported adverse side effects. Thus, argon is widely used in humans as a carrier in diagnostic procedures (Burch et al., Nucl. Med. Commun ., 1993). In addition, breathing argon at normobaric and hyperbaric pressures of 1 to 4 atmospheres absolute (equivalent to up to approximately 400%) has been reported to produce no or minimal side effect [Ackles K. N. and Fowler B., Aerosp. Med., 1971; Fowler B. and Ackles K. N., Aerosp. Med ., 1972; Horrigan D. J. et al., Aviat., Space, Environ. Med., 1979; Imbert J. P. et al., Proceedings of the European Underwater and Baromedical Society , 1989].
[0016] In the preferred embodiment, the invention relates to the use of argon for general pharmaceutical use, to the use of argon for reducing the activity of the mu receptor and vesicular monoamine transporter in a mammal by administering to the mammal a therapeutically allopathic or homeopathic efficient concentration of argon.
[0017] Preferably, argon is administered in combination with a pharmaceutically acceptable carrier, diluent, or excipient. By way of example, in the pharmaceutical compositions of the present invention, argon may be admixed with any suitable binder(s), lubricant(s), suspending agent(s), carrying agents(s), containing agent(s), coating agent(s), solubilizing agent(s), selected with regard to intended route of administration and standard pharmaceutical use and medical practice.
[0018] Argon may also be administered before, after, or simultaneously with another pharmaceutically active agent or a combination of pharmaceutically active agents to decrease, increase or potentiate the pharmacological effect(s) of such agent(s), and improve the mammal's treatment and general condition. The agent(s) may be any suitable pharmaceutically active compound(s), including volatile anesthetics and inert gases such as xenon, helium and nitrous oxide
[0019] Typically, the pharmaceutical composition comprising argon, alone or in combination with another pharmaceutically active agent, is delivered to the mammal by inhalation, or oral, sublingual, transmucosal, transdermal, intravenous (bolus administration and/or infusion), neuraxial (subdural, or subarachnoidal) administration, or by any other available technique, or a combination thereof.
[0020] It is to be noted that the prior art has neither disclosed nor suggested the use of argon as a mu receptor antagonist and/or a vesicular monoamine transporter inhibitor for treating the below-mentioned diseases.
[0021] In one embodiment, the invention relates to the use of argon for reducing the activity of the mu receptor and of the vesicular monoamine transporter by administering to the mammal a therapeutically effective concentration of argon for treating a pathological condition associated with the mu receptor and/or the vesicular monoamine transporter, particularly:
[0022] Stress-induced disorders, such as anxiety, nervousness, tension, jumpiness, excitability, reduced social interactions, and other responses related to previous exposure to stressful and/or traumatic conditions.
[0023] Attention Deficit and Hyperactivity Disorder (ADHD), also known as the hyperkinetic disorder in the International Statistical Classification of Diseases and Related Health Problems of the World Health Organization, by improving executive functions, such as attentional control and inhibitory control, whose impairment causes attention deficits, hyperactivity, and impulsiveness.
[0024] In another embodiment, the invention provides a pharmaceutical composition which comprises argon and a pharmaceutically acceptable carrier, excipient or diluent, wherein the improvement is using argon for manufacturing a medicament for reducing the activity of the mu receptor and of the vesicular monoamine transporter and treating a pathological condition associated with these proteins, particularly:
[0025] Stress-induced disorders, such as anxiety, nervousness, tension, jumpiness, excitability, reduced social interactions, and other responses related to previous exposure to stressful and/or traumatic conditions.
[0026] Attention Deficit and Hyperactivity Disorder.
[0027] The amount of argon employed in the pharmaceutical composition may be the minimum concentration required to achieve the desired clinical effect in human patients. Particularly, the concentration of argon administered by inhalation is between 1 vol % and 99 vol %, advantageously between 20 vol % and 80 vol %, more advantageously between 50 vol % and 80 vol %. But, it is usual for a physician to determine the actual dosage that will be more suitable for an individual patient, and the dose will vary with the response, age, weight, and other specific condition(s) of the particular patient. There can, of course, be individual instances where higher or lower doses are merited, and such are within the scope of the invention.
[0028] The pharmaceutical composition of the present invention may also be for animal administration. Thus, the composition of the present invention, or a veterinary acceptable composition thereof, is typically administered in accordance with veterinary practice and the veterinary surgeon will determine the dose and route of administration that will be most appropriate for a particular animal.
[0029] The present invention is further described by way of examples from in vitro and in vivo studies, and with reference to the accompanying figures.
1. In Vitro Studies
1.1. Mu Receptors
[0030] Methods:
[0031] Membrane preparations were obtained from whole brains of rats untreated (n=4). The brains were crushed and homogenized in TRIS-HCl 50 mM buffer. After centrifugation, the bases of the vials were suspended in the same volume of TRIS-HCl buffer (×2). When the membrane preparation was obtained, the proteins were quantified to prepare in fine a solution at 1 mg/ml. Proteins were quantified using a BCA protein assay. Then, binding studies were performed as follows: solutions to allow calculating total binding were prepared by adding 385 μL of a TRIS-HCl buffer to 330 μL of proteins and 385 μL of [ 3 H]-DAMGO at decreasing concentrations (n=2 per dose, N=12). Solutions to allow calculating non-specific binding were prepared in the same fashion with naloxone instead of buffer. The vials containing these solutions were left open and placed in a closed chamber to allow saturating the solutions with 100 vol % nitrogen or argon. 1000 μL of each vial were placed in a 24-well plate coated with polyethylenimine. After drying, 100 μL scintillant was added to allow counting radioactivity (×3). Specific binding was obtained by subtracting non-specific binding to total binding, and B max , K d , and B max ×1/K d (mu receptor activity) were calculated.
[0032] Results:
[0033] FIG. 1 shows the binding of DAMGO, a mu receptor agonist, in membrane protein preparations in the presence of 100 vol % nitrogen or 100 vol % argon. Compared to nitrogen, argon altered the binding of DAMGO by decreasing B max (number of receptors) by 15% and producing a trend toward reduction of 1/K d (affinity), conditions that resulted in a 60% decrease in mu receptor activity (B max ×1/k d ). These data demonstrate that argon has antagonistic properties at the mu opioid receptor. *P<0.05.
1.2. Type 2 Vesicular Monoamine Transporter
[0034] Methods:
[0035] Rats were killed by decapitation and the brains were carefully removed and placed in ice-cold artificial cerebrospinal fluid (aCSF). Coronal brain slices (400 μm thickness) including the nucleus accumbens (anteriority: −1.2 to +2 mm from the bregma) were cut using a tissue chopper. Before being used, brain slices (n=4 per condition) were allowed to recover at room temperature for 1 hour in oxygenated a CSF. Slices were then placed in a recording chamber (1 mL volume) at 34.5±0.5° C. and superfused at a flow rate of 1 mL/min with aCSF in the presence of amphetamine and air (nitrogen 75 vol %+oxygen 25 vol %) or argon at 75 vol % (with the remainder being oxygen). Control slices were treated with saline solution and air. Carrier-mediated and depolarization-dependent (KCl: 100 mM) dopamine release in the nucleus accumbens were monitored using a polarograph and standard glass-encased nafion-precoated carbon fiber electrodes (David H. N. et al., Biol. Psych ., 2006). For each experimental condition (saline+air, amphetamine+air, amphetamine+argon), changes in dopamine release were calculated using each slice as its own control as illustrated in FIG. 1A : changes in carrier-mediated dopamine release were calculated as [B2−B1], [B3−B1], and [B4−B1]; Peak 2 (P2) and Peak 3 (P3) KCl-evoked dopamine responses were calculated as a percentage change from Peak 1 (P1) KCl-evoked dopamine release taken as a 100% value. Therefore, in the experiments with argon, argon was only administered after Peak 1 (P1) KCl-evoked dopamine release had returned to baseline (B2).
[0036] Results:
[0037] FIG. 2 shows the effects of argon on the amphetamine-induced increase in carrier-mediated dopamine release and the reduction in KCl-evoked dopamine release induced by amphetamine (experimental recording; FIG. 2A ). Amphetamine acts by reversing both the dopamine transporter and the type 2 vesicular monoamine transporter. Blocking the dopamine transporter with specific inhibitors reduces the amphetamine-induced increase in carrier-mediated dopamine release but also restores the reduction in evoked dopamine release induced by amphetamine (Patel J. et al., J. Neurochem ., 2003). In contrast, argon decreases the facilitating action of amphetamine on carrier-mediated dopamine release ( FIG. 1B ) and further potentiates the reduction in Peak 3 (P3) KCl-evoked dopamine release induced by amphetamine ( FIG. 1C ), effects known to result specifically from an inhibition of the type 2 vesicular monoamine transporter (Wilhelm C. J. et al., J. Exp. Pharmacol. Ther ., 2004; Wilhelm C. J. et al., Biochem. Pharmacol ., 2008). The lack of effect of amphetamine in the presence of air or argon (and therefore of argon) on Peak 2 dopamine release is known to be due to the fact that amphetamine yet has not reached its site of pharmacological action (David et al. Biol. Psychiatry, 2006). Taken together these data indicate that argon has inhibitory properties at the type 2 vesicular monoamine transporter. *P<0.02.
2. In Vivo Studies
2.1. Locomotor Studies
[0038] Methods:
[0039] Male spontaneously hypertensive rats (n=7-8 per group), known to show spontaneous locomotor hyperactivity and used as a model for the attention deficit and hyperactivity disorder (ADHD), were treated daily from day 1 to day 3 for 3 h with ‘medical’ air (composed of 75 vol % nitrogen and 25 vol % oxygen) or argon at 75 vol % (with the remainder being oxygen) at a flow rate of 5 L/min in a closed chamber. On day 7, rats were habituated to the activity boxes for 1 h before being recorded for locomotor activity for 1 h 30 min as detailed previously (David et al., Neuropharmacol ., 2004).
[0040] Results:
[0041] FIG. 3 illustrates the basal locomotor response of spontaneously hypertensive rats treated with air (controls) or argon. As recorded on day 7, rats treated with argon from day 1 to day 3 had a lower locomotor activity than rats treated with air. This indicates that argon reduces locomotor hyperactivity in spontaneously hypertensive rats, known to be a model for the attention deficit and hyperactivity disorder (ADHD). *P<0.02.
2.2. Stress-Induced Behavior Studies
[0042] Methods:
[0043] In a first series of experiments, male adult Sprague-Dawley rats (n=6 per group) were treated for 3 h from day 1 to day 3 with ‘medical’ air (composed of 75 vol % nitrogen and 25 vol % oxygen) or argon at 75 vol % (with the remainder being oxygen) at a flow rate of 5 L/min in a closed chamber. None of the animals were habituated to handling with their abdomen side up. Immediately after being treated with either air or argon from day 1 to day 3, and on day 7, rats were handled by an experimenter blind of the rats' gas treatment, with their back placed in the palm of the experimenter and their abdomen side up. The rat's stress level was rated both by the experimenter and an additional observer, also blind of the rats' gas treatment, by counting the number of righting reflex of the animals during a 1-min period on a scale of 0 to 3 with 0 being a total absence of righting reflex and 3 being repetitive righting reflexes. Then, the rats' social interaction was also evaluated. The animals were placed by group of 2 in an open field measuring 90 cm×90 cm for a 10-min period, and the time spent by the animals at a distance comprised between 2 and 5 cm was recorded and taken as a behavioral marker of social interaction.
[0044] In a second series of experiments, from day 1 to day 3, additional male Sprague-Dawley rats (n=6 per group) were placed for 10 min in an open field measuring 90 cm×90 cm, which central area measuring 50 cm×50 cm was equipped for delivering an electric shock to the animals that stayed more than 5 s in the area. From day 4 to day 6, the animals were treated for 3 h with medical air or argon at 75 vol % at a flow rate of 5 L/min in a closed chamber. Immediately after being treated with either air or argon from day 4 to day 6, and on day 8, rats were placed in the open field, and recorded during a 10-min period for the time that they spent in the central area whose electrical circuit was switched off.
[0045] Results:
[0046] FIG. 4 shows the effects of argon on stress-induced behaviors. In the first series of experiments, rats treated with argon had a reduced number of righting reflex when handled abdomen side up ( FIG. 4A ) and further showed an increased number of social interactions compared to control animals treated with air ( FIG. 4B ) as recorded immediately after treatment on days 1 to 3, but also on day 7. Alternatively, in the second series of experiments, rats treated with argon penetrated the central area of the open field to a greater extent than did control animals as recorded immediately after treatment on days 4 to 6, but also on day 8 ( FIG. 4C ). These data taken together demonstrated that argon decreases the stress and anxiety responses induced by stressful conditions, and further improves social interactions. *P<0.05.
2.3. Conclusions
[0047] These data show that argon is a mu opioid receptor ( FIG. 1 ) and vesicular monoamine transporter inhibitor ( FIG. 2 ) that allows reducing both spontaneous hyperactivity in an animal model of ADHD ( FIG. 3 ) and the behavioral responses to stressful conditions ( FIG. 4 ). Therefore, the claims for such discoveries and indications are described hereinbelow.
[0048] As to a further discussion of 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.
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A method of using Argon gas for treating a condition associated with mu opioid receptors and/or the vesicular monoamine transporter activity in a mammal, said method comprising the steps of: a. administering a predetermined concentration of said Argon gas in order to reduce the activity of said mu receptor and of said vesicular monoamine transporter in said mammal.
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[0001] This patent application claims priority from U.S. Provisional Patent Application No. 61/662,386, filed Jun. 21, 2012
FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention relates to a constellation of surveillance satellites for monitoring activity on and above the surface of a planet and, more particularly, to a constellation of satellites in polar orbits, such that satellites in adjacent orbits monitor such activity between their orbits stereoscopically. The primary intended application of such a constellation orbiting the Earth is to detecting the launching of ballistic missiles and to tracking the missiles subsequent to their launch.
[0003] The most pressing need addressed by the present invention is to detect and continuously track ballistic missiles from their moment of launch up to their reentry, which task is commonly referred to as “From Birth to Death” detection and tracking. The prior art on the subject-matter includes activities such as Northrop-Grumman research described in an online article entitled, “STSS Satellites Demonstrate ‘Holy Grail’ of Missile Tracking” (see Appendix no. 1). In this research project, two Space Tracking and Surveillance System satellites tracked an ARAV-B ballistic missile from launch to splashdown.
SUMMARY OF THE INVENTION
[0004] According to the present invention there is provided a satellite constellation including a plurality of satellites in respective substantially polar orbits around a planet, the orbits being substantially evenly spaced longitudinally, the satellites being substantially evenly spaced latitudinally, each satellite bearing at least one sensor for monitoring activity within a field of view, of a surface of the planet, of the each satellite.
[0005] According to the present invention there is provided a method of monitoring activity on the surface of a planet, including the steps of: (a) launching a plurality of satellites into respective substantially polar orbits, the orbits being substantially evenly spaced longitudinally; (b) maintaining a substantially even latitudinal spacing of the satellites; and (c) by each satellite: monitoring activity within a field of view, of a surface of the planet, of the each satellite.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Various embodiments are herein described, by way of example only, with reference to the accompanying drawings, wherein:
[0007] FIG. 1 shows the line of sight to the horizon from a satellite at an altitude of 350 Km;
[0008] FIG. 2 shows a constellation of such satellites in circular polar orbits.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] The principles and operation of a constellation of surveillance satellites according to the present invention may be better understood with reference to the drawings and the accompanying description.
[0010] Although the scope of the present invention extends to monitoring planetary surface activity generally, the primary intended application of the present invention is to monitoring activity on and above the surface of the Earth.
[0011] The present invention takes advantage of the rotation of the Earth beneath the constellation of the present invention in order to minimize the number of low-earth-orbit satellites needed to provide continuous stereo data on the locations of all ballistic threats inside a given size volume that surrounds a given threatened location on the earth's surface. It is assumed herein that each satellite of the constellation carries an omnidirectional electro-optical sensor with a given acquisition range. As an example only and without any loss of generality, the preferred example of the present invention that is described herein is of a constellation of satellites in polar orbit at an altitude of 350 Km.
[0012] Referring now to the drawings, FIG. 1 shows that the line of sight from a satellite at an altitude of 350 Km to the horizon is approximately 2000 Km. An omnidirectional sensor mounted on this satellite has a conical field of view, of the surface of the Earth and of the region above the surface of the Earth, that is defined by these lines of sight. The overlapping fields of view of two such satellites in adjacent polar orbits provide stereoscopic coverage of activity of interest, such as the launching of ballistic missiles, within the region of overlap.
[0013] To minimize the number of satellites needed to provide a sufficiently continuous time-continuous location (CTCL) stereo data relevant to a given threatened zone on the surface of the Earth, all satellites are placed in circular polar orbits, as shown in FIG. 2 that shows a constellation of eleven satellites 10 a through 10 k in respective polar orbits 12 a through 12 k around the Earth. The phases of satellites 10 are evenly staggered relative to each other by latitudinal ˜38° which amounts to ˜4000 Km, denoted by Δ in FIG. 2 . Additionally the orbits of satellites 10 of adjacent orbits 12 are separated in longitude by a common separation which amounts to ˜270 Km on the equator. This feature of the present invention is recited in the appended claims as an “even latitudinal and longitudinal spacing” of satellites 10 . Additionally, the total number of satellites 10 in the constellation and their spread out longitudinal inter-space, combined with the evenly staggered phase of latitudinal ˜38° (˜4000 Km) is such that at any given time there are at least two satellites close enough to a threatened zone 14 so that CTCL stereo data on all threats inside an ˜4,000 Km radius field of view surrounding that threatened zone 14 is acquired. In the present 350 Km altitude, 4,000 Km acquisition range example, the velocity of each satellite 10 is 7.69 Km/sec., so that the orbit period of each satellite 10 is 1.52 hours. In an exemplary embodiment, to obtain CTCL stereo data we place satellites 10 ˜4,000 Km apart latitudinally (Δ≈38° ) This implies that another satellite 10 passes over a threatened zone 14 every 8.67 minuets. This in turn implies that the constellation of this example includes 83 satellites 10 . The distance between the points at which adjacent orbits 12 cross the equator is ˜270 Km in the present example. Fine tuning of the constellation altitude and of both the latitudinal spacing Δ and the longitudinal spacing is done, using thrusters on satellites 12 , as is known in the art, in order to synchronize a specific threatened zone 14 to the constellation front in both the south-to-north passage of the constellation and the north-to south passage of the constellation. Once this has been done, several tens of zones 14 can be covered by the same GBATS constellation.
[0014] 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. Therefore, the claimed invention as recited in the claims that follow is not limited to the embodiments described herein.
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A satellite constellation includes a plurality of satellites in respective polar orbits. The orbits are spaced evenly in longitude and the satellites of adjacent orbits are spaced evenly in latitude. On board each satellite is one or more sensors for monitoring activity within the satellite's field of view.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims benefit of priority from U.S. Provisional Patent Application No. 61/073,885 filed Jun. 19, 2008, which provisional application is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a process for the preparation of glutaraldehyde.
BACKGROUND OF THE INVENTION
[0003] Glutaraldehyde is prepared on an industrial scale by the hydrolysis of 2-methoxy-3,4-dihydro-2H-pyran (MDP) in the presence of an acid catalyst and water. The crude hydrolysis product is distilled to produce a methanol overheads stream, a by-product of the reaction that is itself suitable for recycling and use in other industrial processes, and a tails product containing glutaraldehyde in water. Glutaraldehyde is an important chemical that is used, for example, as a biocide or in leather tanning.
[0004] In the known processes for glutaraldehyde manufacture, some of the unreacted MDP starting material is removed, along with the methanol by-product, by the distillation process. Although the amount is generally small, the presence of the MDP in the distilled methanol is undesirable for a number of reasons, including that yield of glutaraldehyde is reduced as a result of the MDP loss, and that the MDP is a contaminant of the methanol byproduct which, as noted above, is a material that is recyclable and useful in other industrial processes.
[0005] The invention addresses the foregoing shortcomings of the current glutaraldehyde production process.
BRIEF SUMMARY OF THE INVENTION
[0006] The invention provides a process for the preparation of glutaraldehyde. The process comprises:
[0007] (a) reacting in a vessel at from 80° C. to 120° C. a reaction mixture comprising an alkoxydihydropyran compound of formula I
[0000]
[0008] wherein R is C 1 -C 20 alkyl, water, and an acidic catalyst to form glutaraldehyde and the alcohol corresponding to the alkoxydihydropyran compound's alkoxy group;
[0009] (b) removing from the reaction mixture a distillate comprising the alcohol and unreacted alkoxydihydropyran compound, wherein said removal is effected with a distillation column;
[0010] (c) contacting the distillate with a heterogeneous catalyst located externally to the distillation column such that at least a portion of the alkoxydihydropyran compound reacts therein; and
[0011] (d) returning at least a portion of the distillate of step (c) to the distillation column.
BRIEF DESCRIPTION OF THE DRAWING
[0012] FIG. 1 is a schematic drawing of one exemplary embodiment of an apparatus that may be used to carry out the process of the invention.
[0013] FIG. 2 is a schematic drawing of an apparatus showing placement of a heterogeneous catalyst at various locations.
[0014] FIG. 3 is a schematic of an apparatus for testing the effect of heterogeneous catalyst location on the glutaraldehyde preparation process.
DETAILED DESCRIPTION OF THE INVENTION
[0015] As noted above, the invention provides a process for preparing glutaraldehyde. An important feature of the process of the invention is the use of a heterogeneous catalyst to effectively hydrolyze unreacted alkoxydihydropyran compound that carries over with the alcohol byproduct during distillation of the alcohol from the glutaraldehyde reaction mixture. The heterogeneous catalyst is located externally of the distillation column such that at least a portion of the column distillate can be contacted with the catalyst. By hydrolyzing alkoxydihydropyran in the distillate stream, the process advantageously increases the yield of glutaraldehyde and also provides alcohol by-product that is less contaminated with alkoxydihydropyran.
[0016] The distillation column for use in the invention is preferably a multitray setup containing sufficient theoretical plates (typically at least 2, more typically at least 20 plates) to effect the desired separation of glutaraldehyde and water from the by-product alcohol. According to the invention, the heterogeneous catalyst may be located anywhere outside the distillation column, provided that at least a portion of the distillate from the column can be contacted with it. For example, the catalyst may be located within the overheads reflux system of a typically equipped column, such as the condenser, the condenser receiver, or the line for the condensate reflux stream. As a further example, the catalyst may be located adjacent to the distillation column such that a liquid or vapor stream from any of the trays above the feed tray of the column can be passed through the heterogeneous catalyst and then returned to the column at an appropriate point. Such point is typically the same tray as the removal point, or one of the immediately adjacent trays to the removal point.
[0017] Positioning the heterogeneous catalyst according to the invention, and particularly where the catalyst is located in the overheads reflux portion of the distillation column, is advantageous since the unconverted alkoxydihydropyran is relatively concentrated at this point thereby improving its ultimate conversion into glutaraldehyde. Importantly, by positioning the heterogeneous catalyst as described herein, the advantages are achieved without significant color forming in the glutaraldehyde product. In contrast, positioning the catalyst within the distillation column, especially in the lower portions of the distillation column where significant concentrations of glutaraldehyde are present leads to polymerization of glutaraldehyde and color formation in the stream caused by the action of the catalyst on glutaraldehyde and related reaction mixture components. Positioning the catalyst in the feed line to the distillation column is also not as advantaged because of the potential for color formation in that stream.
[0018] The heterogeneous catalyst is generally an organic or inorganic acid that is affixed to a solid support. The acidic species should not significantly leach into the liquid stream flowing past it and the solid support should be stable in the presence of the attached acid and the liquid stream which it contacts. Preferred are acid functionalized resin beads (acidic ion exchange resins are one example) or zeolites or clays showing acidic functionality. Most preferred are acidic ion exchange resins, such as DOWEX MSC-1 (available from The Dow Chemical Company) and Amberlyst 15 (available from Rohm & Haas). These most preferred catalysts are particularly advantageous because they do not add substantial acidic species into the streams in contact with them.
[0019] The heterogeneous catalyst may be provided in various forms to facilitate access of the distillate to the catalyst. For instance, the catalyst may be present in a pot, a reactor, or may be in the form of a catalyst bed, filter, or slurry. Whatever the form, it should allow sufficient contact between the flowing stream and the catalyst. Preferred is a pot or reactor having a liquid distributor at the stream inlet, filled or partially filled with the heterogeneous catalyst, and then a filtering or screening device to prevent heterogeneous catalyst from flowing out of the reactor along with the stream which is returned to the distillation column.
[0020] The amount of heterogeneous catalyst desired for the invention is dependent upon several factors and can be readily determined by a person of ordinary skill in the art. The factors include: 1) the residence time (contact time) between the flowing liquid and the catalyst; 2) the temperature of the liquid and therefore the catalyst; and 3) the concentration of acidic sites on the catalyst, often expressed as milli-equivalents per cubic centimeter of resin bed volume. By way of non-limiting example, for a resin acidity of 0.1 to 2 milli-equivalents/cm 3 of resin bed, a typical residence time within the catalyst bed may be 10 seconds or more, and a typical temperature for the overhead reflux stream may be 40° C. to 60° C.
[0021] The process of the invention is useful for preparing glutaraldehyde from an alkoxydihydropyran compound of formula I
[0000]
[0000] wherein R is C 1 -C 20 alkyl. Preferably, R is C 1 -C 6 alkyl, more preferably C 1 -C 3 alkyl. Most preferably, R is methyl (the compound is therefore 2-methoxy-3,4-dihydro-2H-pyran (MDP)). With MDP, the alcohol byproduct is methanol.
[0022] To prepare the glutaraldehyde, the alkoxydihydropyran of formula I is hydrolyzed with water in the presence of an acidic catalyst. In addition to forming glutaraldehyde, the reaction also forms an alcohol of formula R—OH as a byproduct. The type of vessel used for the reaction is not critical. In a preferred embodiment, the reaction vessel is equipped with a central shaft agitator powered by a drive motor and is partitioned into one or more sections which act as continuously-stirred-tank-reactors (CSTR's).
[0023] The reaction is carried out at a temperature of between 80 and 120° C., more preferably 95 to 110° C. Reaction time is typically between about 1 and 24 hours, more typically between about 1 and 3 hours.
[0024] Various acidic catalysts can be used for the bulk hydrolysis reaction, including organic acids such as saturated and unsaturated carboxylic acids having from 1 to 10 carbon atoms or polyfunctional acids such as maleic acid. Preferred are inorganic acids such as phosphoric acid, boric acid, nitric acid, sulfuric acid or acid salts, e.g. NaH 2 PO 4 . Phosphoric acid is particularly preferred. In addition to providing suitable acid strength for efficient catalysis of the reaction, phosphoric acid also generates a pH buffer once partially neutralized with a neutralizing agent, such as sodium bicarbonate. A buffered pH of about 4 stabilizes the glutaraldehyde product. The amount of acid catalyst should be such that an acid concentration in the range from 0.01% by weight to about 0.2% by weight is obtained in the reaction vessel. Typically, the acid catalyst is mixed with water at approximately 0.1% by weight and is co-fed with the alkoxydihydropyran compound into the reaction vessel. Other solvents may be used in addition or in place of the water, such as alcohol, the alkoxydihydropyran, or glutaraldehyde/water mixtures. Further additional water may be added; preferably an amount such that glutaraldehyde is obtained in the desired concentration following removal of the alcohol at the reaction's completion. Preferred glutaraldehyde concentrations are from 5 to 75% by weight, more preferably from 25 to 65% by weight.
[0025] An exemplary embodiment of the process of the invention, in operation, is illustrated in FIG. 1 . Referring now to FIG. 1 , an alkoxydihydropyran and water along with an acidic catalyst, the catalyst being preferably pre-mixed with the water or a portion of the water to make a solution, are fed into one end of a reactor 10 having several internal partitions making it a CSTR. Reactor 10 is further equipped with a central shaft 20 , impellers 30 , and drive motor 40 . The reactor is preferably operated at elevated temperature, such as between 80 and 120° C., more preferably between about 95 and 110° C. Following about 1 to 2 hours of reaction time, the reactor effluent is transferred to a multi-tray distillation column 60 by pumping or pressure feed via line 50 . An intermediate storage vessel can also be represented by line 50 . Within the multi-tray distillation column the by-product alcohol and as noted above, minor amounts of alkoxydihydropyran (typically 2 weight percent or less), is separated from the glutaraldehyde/water product and removed from the system as distillate 80 . The methanol rich distillate 80 is condensed in condenser 90 and then at least a portion of it is contacted with heterogeneous catalyst 70 which, in this exemplary embodiment, is positioned in the overheads reflux line of the distillation column. In this exemplary embodiment, a distillation reboiler for vaporizing liquid to be returned to the distillation column is shown as 100 . The glutaraldehyde/water tails (bottoms) stream is shown as 110 .
[0026] Contacting the portion of distillate stream 80 which is returned to the distillation column (reflux) with the heterogeneous catalyst 70 results in at least a portion of the unreacted alkoxydihydropyran in the distillate 80 to react with the by-product alcohol or water in the stream. When reacted with water, glutaraldehyde is directly produced. The glutaraldehyde thus formed increases the overall product yield. The glutaraldehyde or the alkoxydihydropyran typically also react with the alcohol in the presence of the catalyst to form other materials such as dialkoxypyrans (as well as acetals, hemiacetals, aldehydes, and the like). The dialkoxypyran materials travel down the column due to their higher boiling point and hydrolyze to form additional glutaraldehyde and alcohol below the feed tray in the column where both acid and water are present, thus further increasing glutaraldehyde yield.
[0027] The glutaraldehyde bottoms may be used without further processing, or it can be partially neutralized with a base such as sodium hydroxide, sodium bicarbonate or sodium carbonate to adjust the pH of the stream to a desired level, such as between 3 and 5, in order to increase the stability of the bottoms stream. Additional water or other formulation ingredients may be added to produce different glutaraldehyde formulated products as desired.
[0028] The following examples are illustrative of the invention but are not intended to limit its scope.
EXAMPLES
General
[0029] The Examples compare the placement of a heterogeneous catalyst at two differing locations relative to the distillation column used for separating the alcohol from the bulk reaction. The tested locations are depicted in FIG. 2 . “B” represents positioning of the heterogeneous catalyst according to the invention. “A” represents a non-invention position used for comparative purposes.
[0030] A laboratory apparatus for simulating the effect of the heterogeneous catalyst placement is used in the examples and is depicted in FIG. 3 . As shown, a glass column 200 (1.5 cm inside diameter by about 25 cm long) having Teflon fittings (column to ⅛″ tubing) at each end is filled with glass beads (3 mm) at either end as inert support and the central section filled with an acidic ion exchange resin catalyst. The column is immersed in a temperature controlled and stirred water bath 210 . Fluid to the column is supplied by a flow calibrated peristaltic pump 220 . The feed line 230 is made of 316 S.S. ⅛″ tubing and coiled in the water bath to heat the feed before entering the column. Teflon ⅛″ tubing 240 is used for the outlet and is used to dispense product into a sample container or a storage container as desired. The entire flow path volume from start of catalyst bed to the end of the outlet tubing is approximately 20 ml. After a feed rate change is made the system is run until at least 40 ml of feed (approximately two equipment volumes) is processed before sampling to assure that the product being sampled is representative of that flow rate. This is verified by sampling the run conditions at two different times, separated by the time it takes for at least another 20 ml of feed to be processed. If the two samples do not give similar analytical results then the times of sampling are increased until the sampling does give similar results. In these examples, MDP is used as the alkoxydihydropyran (the alcohol byproduct is methanol).
[0031] For studies at point A of FIG. 2 , the purpose of the catalytic resin bed is to convert as much of the MDP to glutaraldehyde as possible. A typical composition of the feed material tested at this point is about 14 wt % MeOH, 42 wt % glutaraldehyde, 42 wt % water and 2 wt % MDP.
[0032] For studies at point B in FIG. 2 , the catalytic resin bed should hydrolyze some of the MDP to glutaraldehyde and the rest of the MDP to the dialkoxylation isomers of 2,6-dimethoxy-tetrahydro-2H-pyran (both referred to here as DMTHP). A typical composition of the feed material tested at this point is about 96 wt % MeOH, 2 wt % water and 2 wt % MDP.
[0033] The first heterogeneous catalytic resin studied is Rohm & Haas Amberlyst 15-W (strongly acidic, macroreticular polymer resin beads having sulfonic acid groups used in both aqueous and non-aqueous systems. The W indicates that the resin is purchased in a water-wet state). The second resin, Dowex™ M-31, is similar to Amberlyst 15-W (strongly acidic, macroreticular polymer resin beads having sulfonic acid groups used in both aqueous and non-aqueous systems). A third resin tested is Dowex™ MAC resin (acidic, macroreticular polymeric resin beads having carboxylic acid groups used in both aqueous and non-aqueous systems). The Dowex™ MAC resin is included to determine if a “weaker” acid resin performs differently than the strong acid catalysts, especially at point A.
[0034] To simulate production plant temperatures, point A tests are run between 90 and 93° C. and point B tests are run at 41° C.
[0035] Gas Chromatography (GC) is used to examine the effluent for each experiment.
Discussion: Point A Runs
[0036] Runs at point A with strong acid catalysts (Amberlyst 15-W or Dowex M31) are found to rapidly convert the MDP but produce immediate color in the liquid. The resin also becomes dark-colored after just hours of operation. Increasing the feed rates to reduce the residence time in the catalyst bed reduces the color levels in the liquid but not as dramatically as desired. Residence times in the bed of less than 50 seconds are needed and even then the resin discolors quickly and the product gains visible color.
[0037] GC analysis shows that the MDP is greatly reduced and that several new peaks are formed. The identity of some of these peaks is determined using GC/MS to be 5,5-dimethoxypentan-1-al (acetal) and 1,1,5,5-tetramethoxypentane (diacetal).
[0038] Use of the Dowex™ MAC resin, having the “weaker” carboxylic acid functional groups, reduces the advent of color formation but is also less effective at catalyzing the conversion of MDP to DMTHP.
Discussion: Point B Runs
[0039] In these experiments, positioning the heterogeneous catalyst at point B is studied. A 2 wt % MDP and 2 wt % water in methanol stream is passed through a 10.6 cm 3 bed of Dowex™ M-31 resin at 41° C. The material, after passage through the catalyst bed, is analyzed by GC. Samples of the reaction product are taken at multiple feed rates. These feed rates correspond to volumetric space velocities (VSV's; where VSV is defined as volumetric flow rate of stream/volume of catalyst bed; i.e. gallons of feed per hour/gallons of resin bed giving units of hr −1 ) ranging from 5.7 to 56.6 hr −1 . Using the area counts for the MDP peak in each of the GC traces percent conversion of MDP versus VSV can be determined. Data is provided in Table 1.
[0000]
TABLE 1
Flow Rate
~ % MDP
(ml/min)
VSV (hr −1 ) 1
MDP Area Counts
reduction
1
5.7
<1,000
100
2
11.3
<1,000
100
4
22.6
~1,500
99.5
8
45.2
10,650
97.0
10
56.6
23,800
93.3
1 Volumetric space velocity, VSV, (hr −1 ) = 60 * Flow rate of fluid (cm 3 /min)/Volume of catalyst bed, where Volume of catalyst bed = Volume of resin + void volume = Total occupied space (cm 3 ).
[0040] Importantly, under all operating conditions tested with the laboratory equipment, no color was formed when the acidic catalyst was positioned at point B.
[0041] Complete conversion of the MDP to glutaraldehyde and DMTHP is not needed at point B because much of the unreacted MDP will travel through the bed again. For example at a reflux ratio of 3, 75% of this MDP will return to the reflux reactor assuming no MDP conversion occurs within the column itself. The higher the reflux ratio, the less per pass conversion of MDP is required to be readily effective.
[0042] While the invention has been described above according to its preferred embodiments, it can be modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using the general principles disclosed herein. Further, the application is intended to cover such departures from the present disclosure as come within the known or customary practice in the art to which this invention pertains and which fall within the limits of the following claims.
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Provided is a process for the preparation of glutaraldehyde. The process comprises reacting an alkoxydihydropyran with water in the presence of an acidic catalyst. The alcohol by-product distilled from the reaction mixture is subjected to a heterogeneous catalyst that is located external to the distillation column used for distilling the alcohol, thereby increasing glutaraldehyde yield and decreasing the level of alkoxydihydropyran contamination in the alcohol.
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This application is a division of co-pending application Ser. No. 755,865, filed July 17, 1985, entitled "Reduced Calorie Sausage Containing Cooked Rice," and now U.S. Pat. No. 4,735,819.
This invention relates to a food product in the form of an improved substitute for conventional high fat sausage, and a method of making said product.
DESCRIPTION OF THE PRIOR ART
Historically, sausage has tended to contain the maximum amount of allowable fat permitted by regulation. For example, as recently as 15 or 20 years ago, the bulk of the pork sausage, beef sausage, and breakfast sausage manufactured tended to contain the maximum amount of fat allowable under U.S. Department of Agriculture (USDA) regulations, generally about 50% by weight of the total sausage weight In recent years, however, consumer tastes and dietary interests have been changing and meat products with less fat content have become more popular and increasingly demanded in the marketplace Contributing toward the interest in lower fat meat products has been a growing body of scientific research indicating that excessive human consumption of fat, particularly animal fat, is a significant health hazard.
However, in the case of sausage products, it has been found that a substantial reduction of fat content causes the sausage to become tough, dry, less sweet, less succulent, and distinctly less palatable. For example, pork, beef, or breakfast sausage made from red meat having a fat content below about 35% is considered less palatable due to dryness and chewiness This unpalatability is confirmed by scientifically conducted taste panels and published trade literature
In addition to simply increasing the percentage of lean, there have also been efforts to reduce the amount of fat in sausage by including non-meat additives while still attempting to maintain a similar sausage flavor and appearance. One such example is U.S. Pat. No. 3,748,148, issued to Jehle, which discloses the use of admixing granules of Brazil nuts with the meat as a substitute for the fat that has been removed from the meat. According to the patentee, the Brazil nuts are suitable as a substitute for the animal fat in sausage because of their neutral taste, their higher vegetable content, smaller content of carbohydrates and neutral color The Brazil nuts in Jehle cannot, however, be expected to provide the textural qualities of the high fat sausage substitute produced according to the present invention.
Another representative attempt at reducing the amount of fat in sausage is disclosed in U.S. Pat. No. 4,504,515, issued to Hohenester This patent discloses a process for preparing low-fat meat products which precomminute major quantities of lean meat selected from the group consisting of beef, veal, pork and hare, then thoroughly admixing the meat with minor quantities of skimmed milk or whole milk in the presence of less than 5% by weight of seasonings and/or preservatives The milk in Hohenester cannot, however, be expected to provide the textural qualities of the more coarsely ground high fat sausage substitute produced according to the present invention.
In recent years attempts have also been made to fill the market demand for low-fat sausage with various poultry breakfast sausages, such as turkey breakfast sausage. While poultry is generally lower in fat than pork and beef, the poultry sausage currently available on the market is very dry and lacking in juiciness and succulence.
Another attempt in the mid-1970's proposed a sausage made with a high percent of lean meat which resulted in approximately 30% fat content. This product was commercially unsuccessful.
There is also a particular variation of boudin, a blood sausage originating in France, that contains rice. It is produced by first grinding and cooking the meat before it is combined with the rice. The resulting composition is a soft, mushy, pudding-like texture with no resemblance to the high ft sausage substitute of this invention. Further, in boudin the rice is texturally and visually a clearly identifiable component which is in sharp contrast to the food product of this invention in which the rice, at least to the eye and taste of the lay observer, is indistinguishable from the fat.
Another class of sausage products includes the use of non-meat extenders. Originally such extenders were ingredients like bread crumbs and cereal which were simply mixed with higher cost ground meat to lower the cost of the recipe or product. Subsequently, sausage makers developed various milk and cereal derivatives which performed such additional functions as aiding the absorption of fat and the absorption of added moisture to increase finished cooking yield; adding certain protein values to the sausage to improve the emulsion stability and, in certain cases, imparting a different flavor. The underlying reasons for seeking these additional functions remain principally economic; that is, increasing product yields and lowering product costs.
In the past, rice and meat have been used in the preparation of non-sausage foods. Examples of such non-sausage foods that contain meat and rice (in addition to other ingredients) include jambalaya, Spanish rice with meat, poultry dressing, and peppers and cabbage leaves stuffed with a mixture of ground beef, rice and other vegetables. These foods use rice simply as part of a multi-vegetable meat mixture and the food neither resembles nor is identified as a sausage. In addition, unlike the high fat sausage substitute produced according to the present invention, the rice in these products is a clearly identifiable component, both texturally and visually.
SUMMARY OF THE INVENTION
The invention relates to an improved substitute for conventional high fat sausage in which a substantial portion of the animal fat in the high fat sausage is replaced with lean meat and rice. It has been found that the present invention produces a high fat sausage substitute having the widely accepted characteristics of texture, taste and appearance associated with conventional high fat sausage. In addition, the high fat sausage substitute produced according to the preferred method of the present invention has, as contrasted to the USDA pork sausage standard, 60% less fat, 45% less calories, 35% more protein, and a cooking yield 35% higher than conventional high fat sausage.
According to the present invention, when the high fat sausage substitute is a pork, beef or breakfast sausage, the ingredient formulation by weight for the meat portion is lean meat in the amount of between about 40% to 90%, fat in the amount of between about 5% to 35%, rice in the amount of between about 2% to 35%, salt in an amount sufficient to extract the myosin, that is, up to 4% of the weight of the meat-rice mixture, and a bonding agent, which bonding agent may be myosin, or myosin and one or more substances. High fat pork sausage substitute and high fat beef sausage substitute as used herein refers to single species products that in addition to pork or beef may also contain water, sugar, dextrose, salt, spices and curing agents. Additional ingredients may include flavorings, flavor enhancers, antioxidants or typical extenders including cereal, textured vegetable protein (TVP) and dried milk.
High fat breakfast sausage substitute as used herein refers to a product containing the meat from one or more animal species and which may also include the non-meat ingredients listed above for pork and beef sausage substitutes.
In the present invention, the rice, which is an integral part of the product, binds with the meat portion of the formulation to provide the texture, taste and appearance of the substituted fat. It has been found that the rice provides a moist, fat-like character and structure which does not affect the basic meat flavors associated with the traditional higher fat sausage. In this manner, the rice and lean combination replaces a major portion of the fat and imparts an equally pleasing and palatable texture and mouth feel in a low fat product which, without the addition of the rice, would be tougher, drier, chewier, and distinctly less palatable.
While the above ingredients are preferred, the present invention contemplates varying the types of animal species, the fat/lean ratio, the meat/rice ratio, and the addition of other ingredients typically or sometimes used in sausage including, but not limited to, salt, spices, herbs, water, sugar, dextrose, flavorings, flavor enhancers, textured vegetable protein, antioxidants and curing agents. In addition it has been found that the aforementioned and other similar non-meat ingredients can be added to the high fat sausage substitute produced according to the present invention in similar proportions as they are used in conventional sausage without affecting the utility of the present invention. It has been found that the food product of the present invention can be adapted to all the forms, shapes, and processes typically associated with high fat sausage.
DETAILED DESCRIPTION OF THE INVENTION
The method of producing high fat sausage substitute according to the present invention comprises, in general, the following steps.
A mixture of meat, containing both lean and fat, and rice is formed in the presence of a bonding agent in an amount and manner to form a matrix around and among the lean, fat and rice components of the base mixture. Salt is added, if needed, to this base mixture in an amount sufficient to assist the extraction of myosin from the meat. The bonding agent may be myosin, or myosin plus one or more recognized bonding agents such as hydrocolloids, egg albumin, gelatin, flours, starch, or collagen. The quantity of salt added may be anywhere from 0 to 4%. It will be understood that no salt need be added in those instances when there is sufficient salt already present in the base mixture to perform the desired function of assisting the extraction of myosin. Experience has shown that about 3-4% salt is the maximum upper tolerable limit of salt for human palatability.
Both the aforementioned bonding agents and salt may be considered to be additives. Other additives which may be added as desired are flavorings, (such as onions, garlic, celery, parsley, oleo resin spice extracts, and paprika), spices (such as pepper, sage, ginger, thyme, marjoram, fennel), seasoning, water, anti-oxidants (such as butylated hydroxy anisole (BHA), butylated hydroxy toluene (BHT), citric acid, propylgallate), extenders (such as cereals, cereal derivatives, textured vegetable protein, milk derivatives), flavor enhancers (such as MSG, hydrolyzed plant and/or vegetable protein, autolyzed yeast extract), sweeteners (such as natural or artificial sugar, dextrose, synthetic sweeteners such as cyclamates), coloring agents (such as paprika, dyes), smoke, curing agents (such as sodium nitrite alone or in combination with sodium erythorbate, or sodium ascorbate) and vitamins. It will be noted that some substances fall under two or more of the above classes of additives, such as paprika.
Rice may be prepared in a wide variety of ways including hydrating, parboiling or cooking. It is preferred that precooked dried rice be the starting form of rice, with water being added in a proportion of about three parts of water to one part of rice, by weight, to rehydrate the rice prior to addition to the meat.
One of the outstanding features of the product is that the final rice content, regardless of the cooking or hydration method, is indistinguishable from fat globules; that is, only the extremely practiced eye and palate can discern the difference between an individual rice particle and a fat globule in both an uncooked and cooked condition. For all practical purposes, the rice and fat are indistinguishable to the consumer in the specified ranges.
A number of samples of the food product of this invention were prepared generally as follows.
First, water which may vary between approximately 32° F. and boiling is added to rice. The rice is preferably dried, precooked rice, such as Minute Rice sold by General Foods, Riviana Instant Rice sold by Riviana Foods, Inc. or Uncle Ben's Precooked Rice. The ratio of the weight of the water to the weight of the rice when using precooked rice is preferably approximately 3 parts of water to 1 part of rice. The water and rice mixture should preferably remain in a 28° F. cooler for 24 to 48 hours. Although precooked Minute Rice and Riviana Rice have been successfully used in the production of the subject products, it is believed that other forms of cooked and rehydrated rice may also be used.
In the next step, boneless meat, at a temperature of between about 23° F. to 102° F., and having a fat percentage of between 4% to 35% is added to the rehydrated rice. The percent by weight of the meat to the total weight of the high fat sausage substitute may vary between 65% to 98% and the percent by weight of the rehydrated rice to the total of the high fat sausage substitute may vary between 2% to 35%.
In the next step, the boneless meat and rice are coarse ground through a large-hole plate to begin myosin extraction from the meat. This step may also be accomplished by chopping rather than grinding. The rice can be added to the meat either prior to coarse grinding or chopping, or after the meat is coarse ground or chopped.
Next, the meat and rice are blended in a mixer or chopper and the spices, such as salt, sage, black pepper and ginger, are added, although other seasonings and additives could be added as well. The mixing time will vary depending on the equipment that is used, the RPM's, and types of mixing arms or chopper blades, but it is usual for the average time of mixing to be approximately three minutes. During this step, myosin is further extracted from the meat and the myosin envelops the meat and rice components to achieve the unique result of a traditional sausage flavor, texture, and consistency.
In the next step, the mixture is ground through a small-holed plate which has the effect of further extracting and distributing the myosin. A 9/64-inch plate has been used, although other small-holed plates, such as 1/8-inch, 5/32-inch, 3/16-inch, etc., plates may also be used. The effect may also be achieved by chopping or a combination of chopping and grinding. If chopping is used, chopping time is dependent on the chopper speed and number and pattern of the blades. Care should be taken during this step to make certain that the rice particles maintain their structural integrity and that they maintain a size generally similar to the meat particles. The average finished composition particle should be preferably from 1/8 to 1/4-inch in particle size. The resulting composition should preferably have a finished temperature of between 36° F. to 42° F., although the temperature range for the product if prerigor meat is used may range between 23° F. to 102° F.
The composition is thereafter compacted and processed as conventional sausage, either precooked or uncooked. The cooked or uncooked sausage may take any conventional form, including tubes or rolls and links in casings. Alternatively, the product may be cooked or formed raw (with the casings peeled after the product is formed or cooked), or it may be extruded into skinless links or patties, or it may be processed as patties sliced or cleaved from a product that had been stuffed in a casing, or it may be formed into bulk sausage.
While the above methods and procedures are preferred, the equipment can be varied by using a variety of grinding plate sizes and/or grinding and/or chopping cycles and sequences consistent with the manufacture of conventionally manufactured sausage.
The high fat sausage substitute may then be cooked by the consumer by any of the conventional cooking methods.
Several examples of varying ingredients and methods of formulation of compositions within the scope of the invention are as follows. All percentages are based on the total weight of only the meat and rice components of the mixture, except Example 7 which included the addition of free water. Further, hydrated cooked rice, which had been reformulated on the basis of three parts of water to one part of rice, by weight, was used unless otherwise noted as in Example 7.
EXAMPLE 1
The following ingredient formulation by weight percentages was prepared. In this example the finished product will have a finished fat level of approximately 20%.
______________________________________70.0% lean pork19.8% pork fat10.25% hydrated cooked rice100.0%______________________________________
Meat having an internal temperature of 34° F. was placed on a conveyorized scale and the cooked rice having an internal temperature of 40° F. was added to the conveyorized scale with the meat. The hydrated cooked rice was prepared in the following manner: Minute Rice and water were weighed (25% rice, 75% water) and the water and rice were mixed and the mixture was stored in a 28° F. cooler for 24 hours. Both the meat and rice were then ground using a four-hole teardrop plate to reduce the particle size of the meat to approximately two-inch pieces to begin the myosin extraction. The product was then conveyed to a mixer/grinder where the seasonings consisting of salt, sage, black pepper and ginger were added. The product was then mixed for three minutes causing further extraction of the myosin from the meat and a blending of the meat with the rice. The resulting composition was then ground through a 9/64-inch plate and the resulting temperature of the composition was 40° F.
Portions of the composition were stuffed and linked in both natural and collagen casings, using a stuffer and linker. Another portion of the composition was stuffed into cellulose casings, using a stuffer and an automatic linker, and then cooked using a smokehouse. The cellulose casings were then peeled from the fully cooked links, some of which were also prebrowned. Additional portions of the composition were stuffed into plastic film tubing and fibrous casing and then formed as consumer sized tube packages (rolls) and also as longer sticks. Some of these tube packages were fully cooked. Some of the longer sticks were sliced as uncooked patties, and some sticks were cooked and then sliced as precooked patties, some of which were prebrowned. The equipment used for this was a forming and packaging machine, cleaver, and cooker. Another portion of the composition was extruded into skinless links, some of which were packed immediately in boxes and some fully cooked in a counter flow oven thereby producing precooked links, some of which were also prebrowned. Additional portions of the composition were stuffed and linked into both natural and collagen casings, using a stuffer and linker, and fully cooked in a counter flow oven producing precooked links, some of which were also prebrowned. Another portion of the composition was extruded into patties, a portion of the patties being cooked in a counterflow oven to produce a fully cooked patty, some of which were also prebrowned.
EXAMPLE 2
______________________________________66.9% lean beef19.7% beef fat13.4% hydrated cooked rice100.0%______________________________________
The meat having an internal temperature of 34° F. was added to a six-bladed chopper. The chopper at low speed reduced the particle size to approximately 11/2 to 2-inch pieces in three bowl turns. The hydrated cooked rice having an internal temperature of 36° F. was added to the meat and the seasonings consisting of salt, sugar, sage, black pepper and ginger were added to the meat. The hydrated cooked rice was formulated in the same manner as in Example 1, except that it was held for a period of 48 hours prior to being formulated into the product. The product was then mixed in the chopper for 30 low speed bowl turns causing a further extraction of myosin from the meat, and a blending of the meat with the cooked rice. Thereafter the product was conveyed to a grinder and the finished product was ground through a 9/64-inch plate. The finished temperature of the product was 39° F.
Portions of the composition may be stuffed and linked in both natural and collagen casings, using a stuffer and linker. Another portion of the composition may be stuffed into cellulose casings, using a stuffer and an automatic linker, and then cooked using a smokehouse. The cellulose casings may then be peeled from the fully cooked links, some of which may also be prebrowned. Additional portions of the composition may be stuffed into plastic film tubing and fibrous casing and then formed as consumer sized tube packages (rolls) and also as longer sticks. Some of these tube packages may be fully cooked. Some of the longer sticks may be sliced as uncooked patties, and some sticks may be cooked and then sliced as precooked patties, some of which may be prebrowned. The equipment used for this may be a forming and packaging machine, cleaver, and cooker. Another portion of the composition may be extruded into skinless links, some of which may be packed immediately in boxes and some may be fully cooked in a counter flow oven thereby producing precooked links, some of which may be also prebrowned. Additional portions of the composition may be stuffed and linked into both natural and collagen casings, using a stuffer and linker, and fully cooked in a counterflow oven to produce precooked links, some of which may also be prebrowned. Another portion of the composition may be extruded into patties, a portion of the patties being cooked in a counterflow oven to produce a fully cooked patty, some of which may also be prebrowned.
EXAMPLE 3
The following ingredient formulation by weight percentage was prepared:
______________________________________ 29.7% lean pork 27.8% lean beef 7.4% pork fat 9.3% beef fat 25.8% hydrated cooked rice 100.0%______________________________________
The meats having an internal temperature of 37° F. were added to a conveyorized scale with hydrated cooked rice prepared in the same manner as in Example 1 having a temperature of 35° F. (The rice was held in a 28° F. cooler for 72 hours.) The composition was then conveyed through a coarse grinder and the materials were ground through a one-inch plate and the product was conveyed to a mixer/grinder. The product was then mixed for two minutes during which time the myosin was further extracted from the meat. Spices consisting of salt, sugar, dextrose, sage, black pepper and ginger were added. The product was then final ground through a 5/32-inch plate and the temperature of the resulting composition was 41° F. Thereafter the product may be processed in a manner similar to the processing described in Example 2.
EXAMPLE 4
The following ingredient formulation by weight percentage was prepared:
______________________________________ 45.0% boneless turkey 36.0% lean pork 9.0% pork fat 10.0% hydrated cooked rice 100.0%______________________________________
The meats (both the turkey and pork had an internal temperature of 34° F.) were placed on a conveyorized scale and the hydrated cooked rice having an internal temperature of 50° F. was added. The hydrated cooked rice was prepared in the same manner as in Example 1, except that it was held for a period of 25 hours in a 28° F. cooler. Both the meat materials and rice were conveyed to a coarse grinder and thereafter ground through a four-holed teardrop plate to reduce the particle size of the meat to approximately 11/2 to 2 inch pieces. The product was then conveyed to a mixer/grinder and the seasonings or additives consisting of salt, MSG, sage, black pepper and ginger were added. The product was then mixed for 21/2 minutes causing further extraction of the myosin from the meat and a blending of the meat with the rice. The resulting composition was then final ground through a 3/16-inch plate and the resulting temperature of the product was 50° F. Thereafter the product may be processed as earlier described in a manner similar to the processing described in Example 2.
EXAMPLE 5
The following ingredient formulation by weight percentage was prepared to make Italian Sausage:
______________________________________ 71.1% lean pork 17.9% pork fat 11.0% hydrated cooked rice 100.0%______________________________________
The meat having an internal temperature of 34° F. was placed on a conveyorized scale and the cooked rice having an internal temperature of 40° F. was added. The hydrated cooked rice was prepared in the following manner: Riviana rice and water were weighed (25% rice, 75% water) and the water and rice were mixed and the mixture was stored in a 28° F. cooler for 25 hours. Both the meat and rice were then conveyed to a grinder and coarse ground using a four-hole teardrop plate to reduce the particle size of the meat to approximately two-inch pieces. The product was then conveyed to a mixer/grinder and the seasonings consisting of salt, dextrose, black pepper, fennel and red pepper were added. The product was then mixed for three minutes causing further extraction of the myosin from the meat and a blending of the meat with the cooked rice. The resulting composition was then ground through a 3/16-inch plate and the resulting temperature of the composition was 40° F. Thereafter the product may be processed as earlier described in a manner similar to the processing described in Example 2.
EXAMPLE 6
The following ingredient formulation by weight percentage was prepared to make Bratwurst:
______________________________________ 70.1% lean pork 17.5% pork fat 12.4% cooked hydrated rice 100.0%______________________________________
The meat having an internal temperature of 34° F. was placed on a conveyorized scale with rice. The hydrated cooked rice was prepared in the following manner: Riviana rice and water were weighed (25% rice, 75% water) and the water and rice were mixed and the mixture was stored in a 28° F. cooler for 24 hours. Both the meat and rice were then conveyed to a grinder and coarse ground using a four-hole teardrop plate to reduce the particle size of the meat to approximately two-inch pieces. The product was then conveyed to a mixer/grinder and the seasonings or additives consisting of salt, dextrose, MSG, sage, black pepper and celery powder were added. The product was then mixed for three minutes causing a further extraction of the myosin from the meat and a blending of the meat with the cooked rice. The resulting composition was then ground through a 5/32-inch plate and the resulting temperature of the composition was 40° F. Thereafter the product may be processed as earlier described in a manner similar to the processing described in Example 2.
EXAMPLE 7
The following ingredient formulation by weight percentage was prepared:
______________________________________ 70.1% lean pork 17.5% pork fat 3.1% dehydrated cooked rice 9.3% water 100.0%______________________________________
The meat having an internal temperature of 34° F. was placed on a conveyorized scale and rough ground through a four-hole plate. The meat materials were then conveyed to a mixer/grinder and the dehydrated Riviana rice, water at a temperature of 58° F., and seasonings consisting of salt, sage, black pepper and ginger were added to the mixer. The product was then mixed for four minutes causing further extraction of the myosin from the meat and a blending of the meat with the cooked rice. The product was then final ground through a 5/32-inch plate and the resulting finished product had a temperature of 42° F. Thereafter the product may be processed as earlier described in a manner similar to the processing described in Example 2.
EXAMPLE 8
The following ingredient formulation by weight percentage was prepared:
______________________________________70.1% lean pork17.5% pork fat12.4% milled rice cooked from a raw state100.0%______________________________________
The meat having an internal temperature of 37° F. was added to a chopper. The rice was cooked in a steam jacketed kettle with water at a temperature of 190°-200° F., for 15 minutes. After cooking, the rice was rinsed and chilled to a temperature of 5° F. for one hour and then drained. The meat materials were 10 then reduced in a chopper to approximately 11/2 to 2-inch particles in three bowl turns. The cooked rice and seasonings consisting of salt, dextrose, sage, black pepper and ginger were added to the product and the product was mixed in the chopper for 25 bowl turns causing further myosin extraction and a blending of the meat with the cooked rice. The resulting mixture was then added to a grinder/mixer and the product was final ground using a 9/64-inch plate. Thereafter the product may be processed as earlier described in a manner similar to the processing described in Example 2.
End products from the foregoing batches were then judged on the basis of texture, flavor, and appearance and all were determined to be acceptable by current commercial standards.
A further series of samples was prepared and subjected to panel testing. Specifically, a modified hedonic rating scale was used. In this method, the standard nine point hedonic rating scale is modified by eliminating the middle category, "neither like nor dislike," leaving eight categories consisting of like extremely, like very much, like moderately, like slightly, dislike slightly, dislike moderately, dislike very much, and dislike extremely. Each category has an assigned numerical value ranging from 8 for like extremely to 1 for dislike extremely.
In the panel testing, each panelist was presented, with respect to the pork base food product, with a control product sample and five sample mixes and asked to rate each of the six samples on the above described modified hedonic scale. The control product had a content of 52% lean pork, 48% pork fat and no rice and is a commercial product which has enjoyed wide acceptance. All samples in all tests had the same seasonings added as existed in the control sample so as to minimize the effect of spices and seasonings. Since no commercially available control product was available for beef, the panelists were confined to ranking the five beef samples against each other.
The compositions of the test samples and the rating thereof are shown in the following table.
______________________________________TESTNO. LEAN FAT RICE RATING______________________________________PORK1. 72 8 20 5.22. 90 8 2 6.03. 63 35 2 4.64. 73 25 2 6.05. 71 4 25 4.46. 50 25 25 4.27. 60 10 30 2.48. 55 10 35 3.09. 50 10 40 2.410. 40 10 50 1.811. 70 25 5 5.012. 85 10 5 5.813. 80 15 5 6.014. 70 10 20 5.615. 65 15 20 5.416. 55 25 20 4.017. 70 20 10 6.218. 70 20 10 6.2BEEF19. 88 10 2 3.220. 50 25 25 4.221. 70 10 20 4.022. 70 25 5 3.423. 70 20 10 3.4______________________________________ NOTES: Tests Nos. 17, 18 and 23 are approximate, with an accuracy believed to be within plus or minus about 1%. Test No. 18 included a milk powder derivative.
From the above it will be noted that compositions which ranged up to 35% rice, and as little as 4% fat had a rating of 3.0 or above with the variance noted below.
A 3.0 rating is considered to be a commercially acceptable rating on the modified hedonic scale used, though of course a higher rating is preferred. Specifically, on the standard hedonic, a rating of 7.0 is very outstanding (and quite unusual), and a rating in the range of 4.0 up to 7.0 is considered to be commercially acceptable. On the modified hedonic scale used in the above described panel testing, these values translate to 6.0, and 3.0 up to 6.0 respectively.
Compositions which fall within the range of 3.0 and above are epitomized by test nos. 1-8 and 11-23. (Test number 7 is considered an aberration since the compositions of test numbers 5, 6 and 20 which had rice contents only 5% lower than the composition of test 7 had a rating of 4.2 or higher, and the composition of test No. 8, which had a rice content 5% higher than that of test number 7, fell into the acceptable range).
Of particular significance is the fact that compositions which had as little as 15% fat or less, such as the compositions of tests 2, 12 and 13 were judged to be acceptable; indeed, excellent since the lowest rating of these three tests was 5.8. It appears that a very minor amount of rice--only 2% in the case of test 2--is sufficient to yield a commercially viable product in combination with heretofore unacceptably small percentages of fat.
It is also apparent that the fat content may be as low as 4% (see, for example, test 5), and a commercially viable product will result This result appears to be attributable to the substantial quantity of rice present; i e.: 25% in the composition of test 5.
From the foregoing it appears that fat and rice are to a major degree, interchangeable, though it is not known with certainty if the relationship is precisely proportional In any event, a broad range of acceptable ingredients is considered to be the following:
______________________________________ Lean 40%-90% Fat 4%-35% Rice 2%-35%.______________________________________
The aforesaid broad range includes several compositions which are at the low end of acceptability, such as the compositions of tests 8, 19, 22 and 23, all of which are in the 3.0-4.0 range.
Using a preferred rating of about 5.0 and above and a substantial fat reduction of approximately 10% (i.e.: about a 30% decrease from the current minimally acceptable fat content of 35% of the base mixture), it will be noted that the compositions of test numbers 4 and 11-18, at least as to pork, define a rather clearly categorized group. When the compositions of tests 2 and 5 are compared, it will be noted that a relatively small percent increase in the fat content (i.e.: from about 4% in test 5 to 18% in test 2) results in a significant increase in rating. From these facts it is considered that a preferred range has the following nominal compositions:
______________________________________Preferred______________________________________ Lean 55-85% Fat 10-25% Rice 5-20%______________________________________
A number of samples were made up to a nominal composition of lean 70%, fat 20%, rice 10%. With respect to pork, the ratings were above 6 which, as mentioned earlier, is the equivalent to 7 on the conventional hedonic scale which is outstanding. The ratings were not as high, with respect to beef, though still acceptable.
______________________________________Most preferred______________________________________Lean 70%Fat 20%Rice 10%, all percentages being about ± one percent.______________________________________
A typical panel result for a pork base product is set out in the following table:
______________________________________Test Panelist RatingNo. % Fat % Rice 0 K S M B Ave.______________________________________Control 48 0 8 6 5 6 8 6.62 8 2 7 8 3 7 5 6.07 10 30 2 3 2 2 3 2.415 15 20 6 4 7 6 4 5.416 25 20 2 5 3 4 6 4.0______________________________________
The panelist rating is in points in the range of 1-8, with 8 being the highest rating.
In all of the foregoing tabulated samples the lean and fat components of the base were substantially uncooked when in initial mixture with the rice. It should also be noted that all tabulated samples except No. 18 had the same additives as were present in the control sample so that any differences attributable to differences in additives were eliminated or minimized. Further, all samples in the tabulated samples were judged on the basis of texture, flavor, and appearance as were Examples 1-8.
It will be understood that, although specific examples of the invention have been described in detail, modifications can be made within the scope of the invention. Accordingly it is intended that the scope of the invention not be limited to the foregoing disclosure, but only by the scope of the claims when interpreted in light of the relevant prior art.
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A method of manufacturing sausage is disclosed. This sausage is reduced in calories and is prepared by replacing a portion of the fat in the sausage with cooked rice.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
FEDERALLY SPONSORED RESEARCH
[0002] Not applicable.
REFERENCE TO MICROFICHE APPENDIX
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] The invention relates to the operation of an Integrated Gasification Combined Cycle Power Plant (IGCC).
BACKGROUND OF THE INVENTION
[0005] The gasification of coal by reaction with steam and air has been practiced for more than a century. For most of those years it was produced in relatively simple equipment at a pressure slightly higher than atmospheric pressure. Gas produced through coal gasification has been used to provide fuel gas for lighting and heating. In such simple gasification processes, by-products of coke, tars and light oils were produced in sufficient quantities that their values influenced the selling price of the gas. In recent years many of the outlets for the by-products have been replaced by electricity, natural gas and petroleum distillates. In order to compete with electricity, natural gas, and petroleum distillates, more sophisticated equipment for the gasification of coal has been designed and developed. Such newer sophisticated coal gasification processes operate at high pressures and use, as reactants, steam and pure or nearly pure oxygen. Such equipment is costly and complex to operate with the result that such operating units must be large to achieve good economics.
[0006] At the present time power plants for the production of electricity are large and the electricity is distributed through nation-wide networks. There is, however, still a need for plants of all sizes to supply local demands for power and cogeneration. Irrespective of the size of the plant, plant emissions must meet environmental requirements set by governmental authorities. These factors have led to difficulties in the use of coal as the primary fuel for power generation or co-generation plants.
[0007] The design of power plants has also changed with the development of the gas turbine as a highly efficient power unit, especially when combined with a heat recovery steam generator and steam turbine. Gas turbines, however, operate solely on gaseous or liquid fuels. Clean fuel gas produced by large coal gasifiers, in conjunction with clean up equipment, may be used in generating power with gas turbines. Large gasifiers which can convert from 1,200 to 2,500 tons of coal per day to gas and provide fuels to gas turbine combined cycle plants of 250 to 500 megawatt capacity are known.
[0008] Although there is a demand for gas turbine based power plants in that size range, gas produced from coal has not generally been used to produce electrical power because the complexity of the equipment and operating costs of oxygen based systems make the use of coal economically impractical. However, for many decades small and medium sized gasifiers have been used to provide fuel gas, at low pressure, to such plants as brick works, glass plants and lime kilns. Such small and medium size gasifiers use air as a reactant and so the quality of the gas produced is lower than that of the large plants that use oxygen, particularly as regards gas heating value and composition. Because the operating pressure is low the normal method for producing the air necessary for the gasification is through the installation of air blowers. The use of air blowers is very inefficient with the result that the gasification process has a low efficiency. In cases where the quantity of air is large and the pressure higher, axial flow compressors, which have high efficiencies, can be used. Such is the case with the compressors used in gas turbine engines.
[0009] The gas turbine consists of a highly efficient air compressor that supplies air to a combustion chamber in which fuel is burned. The hot gas produced flows into an expander where it produces work. This expander is connected to the compressor and also to a mechanical drive commonly to an electricity generator. It is usual to supply the fuel in the form of natural gas or fuel oil, which have heating values on the order of 21,000 British Thermal Units per pound and the fuel supplied amounts to slightly less than 2% of the air supplied. The heating value of coal gas is about 3,000 British Thermal Units per pound and to achieve the same gas temperature in the gas turbine the amount of fuel added must be at least 14% of the airflow. This leads to a substantial increase in gas flow through the expander and a consequent increase in the power produced. This higher power, in some cases, is higher than the value that can be transmitted to the electricity generator without exceeding the mechanical limits of the drive shaft. The normal method of preventing this condition is to reduce the airflow to the compressor and hence the flow through the turbine.
SUMMARY OF THE INVENTION
[0010] Embodiments of the invention provide for the improvement of the operating efficiency of low pressure gasifiers by linking the air supply to the compressors of the gas turbine being used in an Integrated Gasification Combined Cycle Power Plant (IGCC) by extracting air from the outlet of the gas turbine compressor and passing it through an expander to reduce the pressure to that required by the gasifier and at the same time producing power.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic representation of a gas turbine and gasifier system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] Embodiments of the invention proposes a more efficient way to operate a gas turbine by allowing the normal amount of air to enter the compressor by extracting an amount of air from the exit of the compressor equal to the air quantity requirement of the gasifier or gasifiers. In embodiments of the inventive process, air in an amount equal to that needed by the gasifiers is withdrawn from the gas turbine air compressor, passed through an expander and fed into the gasifier, thus eliminating the need for air blowers and saving the power that such air blowers would have consumed.
[0013] Referring to FIG. 1 , coal ( 1 ) is passed into a gasifier ( 2 ) where it is turned into gas. The gas leaves the gasifier at exits ( 3 ) and ( 4 ). The gas is passed into a scrubber tower ( 5 ) that removes sulfur from the gas. Some of the gas enters a compressor ( 6 ), from which it exits at a high enough pressure ( 7 ) to that needed for entry to the combustion chamber ( 8 ) of the gas turbine. Air from the gas turbine compressor ( 9 ) is split into two streams ( 10 ) and ( 11 ) of which stream ( 11 ) passes to an expander ( 12 ) and thence to the bottom of the gasifier ( 13 ). Meanwhile stream ( 10 ) passes to the combustion chamber ( 8 ) to provide the oxygen needed for the fuel to burn. The hot gas from the combustion chamber ( 8 ) passes into the gas turbine ( 14 ), which creates the power needed to drive the compressor ( 9 ) and the alternator ( 15 ). The exhaust gas from the gas turbine ( 16 ) passes to a heat recovery steam generator ( 18 ) where it is cooled by heat exchange with water ( 19 ) to provide high pressure steam ( 20 ) to drive a steam turbine ( 21 ) and electricity generator ( 22 ). Steam exiting the steam turbine ( 21 ) is cooled in a condenser ( 23 ) by cold water ( 24 ) supplied from a cooling tower ( 25 ) or by air in an air-cooled condenser. In some cases more steam, and hence more power, can be produced by burning some of the coal gas ( 17 ) in the entry duct of the heat recovery steam generator.
[0014] This embodiment of the invention relates to the gasification of coal using air and steam as the reactants to produce a product gas, which has properties suitable for use as a fuel for gas turbines. As shown in FIG. 1 , air is introduced into the bottom of the gasifier to produce gas, which rises through the gasifier and leaves the ash in the coal to be removed through the bottom of the gasifier. In its passage through the gasifier the coal is converted to an acceptable fuel gas, and such reaction should occur at a pressure of from 20 to 90 pounds per square inch absolute.
[0015] The gas produced is comprised of a mixture of carbon monoxide, carbon dioxide, hydrogen, nitrogen, methane, ethane, ethylene, hydrogen sulphide and a trace of carbonyl sulphide and carbon disulphide. The sulfur compounds are removed in a clean-up plant and the gas is then ready to be used and is environmentally suitable for any purpose and particularly as fuel for gas turbines.
[0016] As an example coal, with a composition of carbon 52.58%, Hydrogen 3.65%, Nitrogen 0.72%, Oxygen 13.10%, Sulfur 0.23%, Water 25.00%, Ash 4.72%, can be gasified under a pressure of 30 pounds per square inch absolute to provide gas for a gas turbine. The approximate quantity of gas produced from one gasifier would be 588,000 standard cubic feet per hour and would have a heating value of 3,118 British thermal units per pound. The composition of the gas would be approximately 28.39% Carbon Monoxide, 18.26% Hydrogen, 41.61% Nitrogen, 5.86% Carbon Dioxide, 5.08% Methane, 0.10% Ethylene, 0.13% Ethane and less than 0.01% sulfur.
[0017] The output of thirteen gasifiers producing this quality of fuel would be sufficient for a single SGT6-3000E or equivalent gas turbine to produce, at sea level and 59° F., 144 Mw of electricity. This quantity, however, exceeds the maximum, of 135 Mw, that can be transmitted to the electricity generator. Conventionally, this would be achieved by throttling the flow of air to the compressor of the gas turbine by about 10%. An alternative way to reduce the flow to the combustion chamber is to extract air from the outlet of the compressor and use it for some other purpose.
[0018] Gasifiers typically operate at a pressure of from about 30 to about 90 psia and the air must be compressed to that level. This may be achieved by the use of centrifugal blowers. It has been discovered that by extracting air from the gas turbine and reducing its pressure to that of the gasifier, by passing it through an expander, a considerable saving in the power can be gained compared with using blowers. The effect on performance and efficiency of throttling the air or extracting the air is presented in the table below.
[0019] In another example coal, with a composition of Carbon 49.21%, Hydrogen 3.51%, Nitrogen 0.71%, Oxygen 11.42%, Sulfur 0.35%, Water 29.90%, Ash 4.90%, can be gasified under a pressure of 30 pounds per square inch absolute to provide gas for a gas turbine. The approximate quantity of gas produced from one gasifier would be 575,000 standard cubic feet per hour and would have a heating value of 3,132 British thermal units per pound. The composition of the gas would be approximately 30.60% Carbon Monoxide, 16.62% Hydrogen, 42.64% Nitrogen, 4.53% Carbon Dioxide, 5.54% Methane, 0.12% Ethylene, 0.19% Ethane and less than 0.01% sulfur.
[0020] The output of a Frame 7 FA turbine operating on this quality of fuel and at a temperature of 59° F. has been compared for cases with extraction and without extraction at altitudes of sea level and 5000 feet. The results are given in the table below.
Frame 7FA Turbine SGT6-3000E Extraction No Extraction Extraction No Extraction KW Throttling Extraction Sea Level Sea Level 5,000 ft. 5,000 ft. Gas Turbine 131,631 131630 187,552 210.624 156,532 175,520 Steam Turbine 80,5443 80,544 124,638 130,798 100,797 111,516 Expander 0 7,847 11,028 0 9,076 0 Parasitic Loss 6,365 6,365 9,366 10,243 7,720 8,611 Compressor 19,977 19,977 28,316 31,998 23,635 26,665 Blower 6585 0 0 9,162 0 8,847 Gas Clean Up 777 777 1,017 1,017 837 837 Solids Handling 1,165 1,166 1,526 1,705 1,256 1,435 Net Power 179,248 185,055 282,993 287,297 232,959 240,540 Heat Rate Btu/Kwh 9,872 9,562 8,124 8,945 8,121 8,991 Dry, Ash Free Coal 1,565 1,565 2,048 2,290 1,686 1928 Used ton/day
[0021] As can be seen from the table the use of extraction leads to up to 10% reduction in the fuel required and a reduction in the number of gasifiers needed per kilowatt generated.
[0022] Certain embodiments of this invention are not limited to any particular individual features disclosed, but include combinations of features distinguished from the prior art in their structures and functions. Features of the invention have been described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. These may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. This invention is to be read to include any legally equivalent devices or methods, which do not depart from the spirit and scope of the present invention.
[0023] In conclusion, therefore, it is seen that the present invention and the embodiment(s) disclosed herein are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited is to be understood as referring to all equivalent elements or steps. The description is intended to cover the invention as broadly as legally possible in whatever forms it may be utilized.
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A method of using an apparatus for producing electric power or mechanical drive in which fuel gas produced in a gasifier using air as an oxidant is supplied to the gasifier by extraction from the exit of the air compressor of a gas turbine.
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FIELD OF THE INVENTION
This invention relates to a steam generator, especially for use in a high capacity humidification system suitable for industrial, commercial, hospital and other relatively large size installations. Maintenance requirements are reduced by minimizing the build-up of mineral deposits on the surfaces of the evaporation tank and, instead, causing such build-up to occur preferentially on porous mats which can easily be replaced or cleaned.
BACKGROUND OF THE INVENTION
It is well-known to use humidifying systems which employ steam generators. The boiling of the supply water to generate steam is advantageous because bacteria present in the supply water are killed and minerals present in the supply water tend to remain in the evaporation tank. Thus, the steam fed into the heating, ventilating and air conditioning system is clean and sterile.
The supply water in such devices is the usual local supply water which invariably contains insoluble mineral salts, such as calcium carbonate. Thus, over time, deposits of dirt, dust, lime and other minerals accumulate on various interior surfaces of the steam generator, including the heat exchange surfaces and walls of the evaporation tank. This reduces the efficiency of energy transfer from the heat source to the water. Frequent removal of accumulated, adhering, mineral deposits is required. The task of removing accumulated mineral deposits is at least bothersome and it may be quite difficult.
It has been suggested to drain periodically some of the water in the evaporating tank in order to reduce the build-up of mineral concentration therein. This is not fully satisfactory because a relatively large quantity of water is circulated through and is discarded from the evaporation tank during operation. This mode of operation is unsuited for areas where water conservation is desireable. Moreover, the additional tanks, pipes, valves, etc. that are required increase the cost of the installation and, over time, mineral deposits may adhere to them and require cleaning.
SUMMARY OF THE INVENTION
According to the present invention, the amount of minerals and other solids deposited on internal surfaces of the evaporation tank of a steam generator, including heat exchange surfaces thereof, is reduced by contacting the water in the evaporation tank with one or more porous, non-woven, fibrous mat(s) having a high surface area. The mat(s) are made of fibers of synthetic fiber-forming resin. The mat(s) are effective to cause the minerals to deposit on the mat(s) in preference to other internal surfaces of the evaporating tank, especially heat exchange surfaces thereof. More particularly, the mat(s) are non-woven, porous, textile-like materials in flat sheet form. The mat(s) have a high ratio of void volume to surface volume and have interconnected interstices or voids. The mat(s) are composed of water-insoluble fibers assembled in webs of long single filaments arranged randomly. The filaments have a diameter or fiber size of from about 0.1 to 45 denier. The mat(s) have a basis weight (weight per unit area) of about 10 to 800 g/m 2 , preferably about 17-180 g/m 2 . The mat(s) have planar-isotropic or non-directional properties owing to the random lay down of the filaments. The filaments are thermally bonded to each other where they contact by fiber-to-fiber fusion. The bond-to-bond distances are from about 50 to 100 times the filament diameter. The mat(s) preferably are compressible. The fibers typically have a length of from about 1.2 to 200 cm. It is preferred that the mat(s) are spun-bonded mat(s) consisting essentially of randomly distributed, polyester fibers, preferably polyethylene terephthalate fibers, which are thermally bonded to each other at the locations where they contact each other.
In use, the mineral deposits form substantially cylindrical, sheath-like coatings of crystalline mineral particles on the surfaces of each of the individual synthetic resin fibers of the mat(s), that is, each fiber forms the central core and the fine mineral crystals form a cylindrical sheath encircling the core. This is shown in FIG. 8, which is a photograph, at 60 magnifications, of two fibers of a mat of a steam generator which was operated for 980 hours using the local water supply of the city of Three Rivers, Michigan. In FIG. 8, fragmentary portions of the mineral coating on the fibers were broken off to expose portions of the core fibers. FIG. 9 is a photograph at 10 magnifications, of a fragment of the mat. In the mat of FIGS. 8 and 9, the individual fibers of the mat had a diameter of about 0.001 inch. The cylindrical mineral-coatings on the individual fibers had a diameter of about 0.013 inch. The outer diameters of the mineral coatings on the fibers progressively increase as time passes during operation of the humidifier. The exposed surface areas of the coated fibers also progressively increase as more crystalline deposits adhere thereto and this is effective to increase further the amount of minerals that are deposited on the fibers whereby the collection efficiency of the mat(s) improve(s). Eventually, however, the fibers become so heavily encrusted with mineral deposits that the interstices or spaces between the fibers are nearly filled up. This then reduces the total surface area on which additional mineral deposits can form and, thus, reduces the collection efficiency of the mat(s). The original mat(s) can then be replaced by new mat(s), or the original mat(s) can be cleaned, so that the process can be continued. Because of the high collection efficiency of the mat(s), a very high percentage, usually about 90%, of the minerals in the supply water are deposited preferentially on the mat(s). The amounts of solids that are deposited on other surfaces of the evaporation tank, especially heat exchange surfaces thereof, are quite small and are much less than the amounts that are deposited thereon when the mat(s) are not used.
The mat(s) do not perform merely a filtering or mechanical straining or screening of the solids that are created by the generation of steam in the evaporation tank. This is shown by the fact that the individual mineral particles thus formed are smaller than the interstices in the mat(s) and would pass therethrough if only mechanical straining or screening were involved. The inventors have not, to date, fully clarified the mechanism by which the minerals preferentially deposit in the form of individual thick sheaths or coatings on the individual fibers of the mat(s). At present, the inventors believe that the mechanism is substantially as described in the following explanation. The invention, however, is not limited to the correctness of this explanation. According to this explanation the mineral particles that form in the evaporation tank during steam generation are attracted to the fibers of the mat(s) because the zeta potential of the fibers is higher than the zeta potentials of the surrounding evaporation chamber surfaces and the heating elements. Once attracted to the fibers, the mineral particles are retained thereon by van der Waal's forces. This explanation is related to the mechanism described in U.S. Pat. No. 4 007 114. However, unlike No. 4 007 114, this invention does not require surface treatment of the fibers to introduce cationic groups therein.
Other possible explanations for the preferential deposition of mineral particles on the fibers are that the mineral particles flocculate by interparticle bridging and/or the fibers provide nucleation sites on which the crystalline deposits can form as they crystallize out of solution during steam generation in the evaporation tank.
An apparatus, according to the invention, comprises a housing having an opening through one wall thereof. A drawer is movably disposed in the opening so that it can be moved between an open position outside the housing and a closed position in which it sealingly engages the housing so that steam that can be generated therein and can be discharged therefrom only through a discharge opening. An evaporation tank is mounted on the drawer for movement therewith. When the drawer is in the closed position, the evaporation tank is disposed inside the housing so that steam can be generated therein and thence fed through the discharge opening into the ductwork of the heating, ventilation and air conditioning system, for humidification purposes. When the drawer is open, the interior of the evaporation tank is exposed. The evaporation tank can be heated by internal or external heating means of any desired type, for example as listed thereafter. It is preferred, however, to use an internal electric resistance heating unit in order to boil the water in the evaporation tank. One or more of the non-woven, fibrous mats, described above, is (are) removably disposed inside the evaporation tank so as to be substantially completely immersed in the water during the steam generation, thereby to cause the crystalline mineral deposits that are formed during steam generation to form preferentially on the mat(s), in preference to other internal surfaces of the evaporation tank.
Although the invention does not entirely eliminate the problems of mineral deposits in steam generators, it does reduce the severity of the problems and makes possible a more easily manageable maintenance procedure because the replacement of the mat(s) is similar to replacing a furnace filter in a conventional household, forced hot-air, heating system.
Accordingly, it is an object of the invention to provide an inexpensive, disposable mat in a steam generator, which mat is effective to remove most of the mineral deposits as they form in the evaporation tank during steam generation, whereby to reduce the amount of such mineral deposits that form on other internal surfaces of the evaporation tank.
Another object of the invention is to provide a steam generator having a mat or mats, as aforesaid, which do not interfere with the operation of the steam generator.
A further object of the invention is to provide a steam generator having a mat or mats, as aforesaid, in which the evaporation tank can be moved between a closed position for effecting steam generation and an open position in which the mat or mat(s) is(are) exposed for easy removal and replacement by fresh mat(s).
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a steam generation unit according to the invention;
FIG. 2 is a sectional view substantially taken along the line II--II of FIG. 4;
FIG. 3 is a side elevational view of the steam generation unit of FIG. 1 with the drawer in an open position and showing one of the mats partially removed from the evaporation tank;
FIG. 4 is a view like FIG. 1, on an enlarged scale, with the tank front wall panel and front drawer panel removed and adjacent parts of the housing broken away;
FIG. 4A is a view similar to FIG. 4 but with the mat(s) and their surrounding framework(s) removed;
FIG. 5 is a view like FIG. 2, but substantially taken on the line V--V of FIG. 4 and showing the drawer in an open position;
FIG. 6 is a front view of a mat and its supporting framework;
FIG. 6A is an enlarged fragment of FIG. 6 showing one end of an elongate metal strip on the bottom of the framework;
FIG. 7 is a side elevational view of the supporting framework of FIG. 6;
FIG. 7A is an enlarged fragment of FIG. 7 showing the FIG. 6A strip in end view;
FIG. 8 is a photograph, at 60× magnification, of two fibers of a mat after 980 hours of use in a steam generator, portions of the mineral deposits on the fiber having been removed in order to reveal the underlying fiber;
FIG. 9 is a photograph, at 10× magnifications, of a portion of a mat after 980 hours of use in a steam generator;
FIG. 10 is a sectional view substantially taken along the line X--X in FIG. 2 and showing a seal;
FIG. 11 is a sectional view substantially taken along the line XI--XI in FIG. 5;
FIG. 12 is a sectional view substantially taken on the line XII--XII in FIG. 4;
FIG. 13 is a sectional view substantially taken on the line XIII--XIII of FIG. 4A, with the screen and tank bottom wall partly broken away.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, the steam generating unit is indicated generally by the reference number 10 (FIGS. 1 and 2). The steam generating unit 10 is comprised of a shell or housing 11 having a front wall 12, a back wall 13, a pair of opposite end walls 14 and 16, a top wall 17 and a bottom wall 18. The front wall 12 has a large size, drawer opening 19 therethrough. A tilt-out drawer 21 is moveably disposed in the opening 19 for movement between a closed position (FIG. 2) and an open position (FIGS. 3 and 5). A steam discharge pipe 22 extends through the top wall 17. A drain pipe 23 extends through the bottom wall 18. The housing 11 is substantially rectangular in front elevational view (FIG. 1) and, also, in top plan view.
The tilt-out drawer 21 is comprised of a hollow front panel 26 containing a heat insulation layer 27, for example, a glass fiber mat. A shelf-like base wall 28 extends rearwardly (FIG. 2) from and is fixed to the lower edge of the front panel 26. The base wall 28 is substantially parallel with the bottom wall 18 of the housing 11 in the closed position of the drawer 21 (FIG. 2). An upright triangular gusset plate 29 is provided at one of the side edges (the right edge in FIG. 4) of the drawer 21 and is secured to and extends between the inner side of the front panel 26 and the base wall 28 for the purpose of strengthening the assembly. A horizontal hinge 31 hingedly connects the lower edge of the drawer 21 to the front wall 12 of the housing 11 at the lower edge of the drawer opening 19 so that the drawer 21 can be pivoted outwardly about a horizontal pivot axis close to its lower edge from an upright, closed position (FIG. 2) in which it closes and seals the drawer opening 19 to an upwardly and outwardly inclined, open position (FIGS. 3 and 5), in a manner similar to the way an oven door of a household cooking range can be tilted outwardly. A flexible connector 32 (FIG. 3), such as a cable or chain, is provided to limit outward tilting movement of the drawer 21.
The drawer 21 is normally releasably held in its upright, closed position by means of front facing screws 33 (FIGS. 1-3). The screws 33 are mounted on opposite side edges of the drawer 21 close to the upper edge thereof. The screws 33 are threaded into nuts 34 which are fixedly mounted at the front wall 12 of the housing 11 on opposite lateral sides of the drawer opening 19 and in alignment with the screws 33 when the drawer 21 is closed.
An open-topped evaporation tank 36 is removably mounted on the interior side of the front panel 26 of the tilt-out drawer 21. The evaporation tank 36 is comprised of two side walls 37 disposed adjacent to the opposite lateral side edges of the drawer opening 19, an inwardly sloping, funnel-like bottom wall 38, a front wall 39 and a back wall 41. The upper edges 37a of the two side walls 37 are angled upwardly and forwardly toward the front panel 26 to permit the tilt-out drawer 21 to be tilted outwardly as shown in FIGS. 3 and 5. The upper side of the evaporation tank 36 is open. The evaporation tank 36 is adapted to contain a supply of water to be evaporated.
Suitable means are provided to heat the water in the evaporation tank 36 to boiling. In the illustrated embodiment, the heating means is an electrical resistance heating unit 42 which is disposed inside the evaporation tank 36 directly above the bottom wall 38 thereof. As shown in FIG. 4, the heating unit 42 is supported on a screen 43 which rests on the bottom wall 38. The screen 43 is of saw-tooth or substantially sinuous shape in cross-section. In addition to supporting the heating unit 42, the screen 43 also screens out large particles which fall to the bottom of the evaporation tank 36 so that they do not enter the water-discharge opening described below. It is to be understood, however, that a wide variety of internal and external heating units can be employed, including boiling electrodes disposed inside the evaporation tank 36, a heat exchanger connected to a live steam supply or external burners.
A steam collection dome 46 (FIG. 5) is stationarily mounted in the upper portion of the housing 11 directly above the position occupied by the drawer 21 when said drawer is in its normal, upright, closed position (FIG. 2) inside the housing 11. The dome 46 has a front wall 47, two side walls 48 and a back wall 49, which walls correspond to and constitute vertical extensions of the front wall 39, the side walls 37 and the back wall 41 of the evaporation tank 36 when said tank is in its FIG. 2, normal, upright, closed position inside the housing 11. The dome front and back walls 47 and 49 are fixed respectively to an inturned lip 47a (FIG. 5) of the housing central front wall 12 and through a hat cross-section spacer 49a to the housing rear wall 13. The lower edges 51 of the side walls 48 are angled upwardly and outwardly (forwardly) in the same way as the upper edges 37a of the side walls 37 of the evaporation tank 36.
As shown in FIG. 10, the upper edges of the front, back and side walls of the evaporation tank 36 and the lower edges of the front, back and side walls of the steam collection dome 46 have inturned flanges 52 and 53 which are disposed close to, and extend substantially parallel to, each other. The opposing surfaces of the flanges 52 and 53 have sealing means, such as elastically compressible, closed cell, foam strips 54, mounted thereon, for example, by a water-resistant adhesive. When the tilt-out drawer 21 is in its normal, upright, closed position inside the housing 11 and the screws 33 are tightened, the sealing strips 54 are pressed into sealing engagement with each other to provide a steam-tight seal between the entire upper edge of the evaporation tank 36 and the entire lower edge of the steam collection dome 46.
The steam discharge pipe 22 (FIG. 2) communicates with the upper end of the steam collection dome 46 so that steam generated in the evaporation tank 36 can be discharged from the steam generating unit 10 and used for humidification purposes.
A pair of horizontal, elongated guides 56 and 57 (FIG. 4) are mounted on the inner sides of the side walls of the opening 19 of the housing 11 close to the upper end thereof. The guides 56 and 57 are hat-shaped in cross-section and have guide flanges 56a and 57a which slidably engage the outer sides of the side walls 37 of the tilt-out drawer 21 whereby to slideably engage and guide the drawer during tilting movement thereof. The nuts 34 are fixed, as by welding, inside the channels of the guides 56 and 57 at the front end thereof. The rear end portions of the guides 56 and 57 may also laterally locate the dome 46 in the housing 11.
At least one mat 61 (FIGS. 2, 4 and 5), here a horizontal array of four upright mats 61, is disposed inside the evaporation tank 36. The mats 61 are upright and are parallel with each other and with the front wall 26 of the drawer 21 (FIG. 5). The mats 61 extend upwardly from adjacent to the heating means 42 to close to the open upper end of the evaporation tank 36.
The mats 61 are fixedly located in, but easily removable from, the evaporation tank 36. For this purpose, the inner sides of the side walls 37 of the evaporation tank 36 each have two vertically spaced-apart, horizontal, elongated guides 63 (FIGS. 2 and 4a) mounted thereon. The guides 63 are hat-shaped in cross-section with edge flanges 63a fixed on the tank sidewall 37 and a central base web 63b spaced from the sidewall 37. The side edges of each mat 61 are vertically slidably received in opposed vertical channels 64 each having a central web fixed to and crossing the base webs 63b of the adjacent guides 63 so that the mats can be slid upwardly out of and downwardly into the evaporation tank 36. Each vertical channel 64 has a pair of inwardly extending, laterally spaced-apart flanges 64a and a bottom flange 64b. The paired flanges 64a laterally overlap and slidably engage the front and rear surfaces the adjacent vertical edge portion of their associated mat 61 and define a vertical guide slot for laterally fixing the mat 61. The mat 61 rests on the bottom flange 64b. Thus, the mats 61 are removably mounted in spaced-apart, parallel relationship and are vertically slidable into and out of the evaporation tank 36. See for example the partially removed rearmost mat 61 in FIG. 5.
As indicated above, each of the mats 61 can be individually removed from the evaporation tank 36. In addition, the entire evaporation tank 36, including the mats 61 and the heating unit 42, can be removed as a unit from the tilt-out drawer 21, for example, when it is necessary to clean or replace the heating unit 42 or to make other repairs. For this purpose, as shown in FIG. 11, the tank front wall 39 extends laterally beyond the side walls 37 of the evaporation tank 36 to form laterally outwardly extending flanges 71 which are vertically slidably receivable in laterally opposed, vertical channels defined by sinuous mounting strips 72 fixed to the inner side of the front wall 26 of the tilt-out drawer 21. Thus, the entire evaporation tank 36 can be slid vertically upwardly relative to the tilt-out drawer 21 when said drawer is in its open, outwardly tilted FIG. 5 position, in order to remove the evaporation tank.
Referring to FIG. 4, the lower wall 38 of the evaporation tank 36 has an inlet/outlet port and, in communication therewith, a fixed, short, downwardly extending nipple 73. The nipple 73 is vertically slidably received inside the upper end of a cup-like fixture 74 which is fixedly mounted on the base wall 28 of the tilt-out drawer 21. The fixture 74 has two ports 76 and 77. As schematically shown in FIG. 4a, port 77 is conventionally connected by a flexible hose 77a to a drain valve DV for controlling discharge of waste water from the evaporation tank. Port 76 is conventionally connected by a flexible hose 76a, conduit 76b, anti-back-siphon funnel/spigot unit 76c, and inlet valve IV to a water supply S for filling the evaporation tank.
Suitable conventional controls are provided to supply water to and discharge water from the evaporation tank and to turn on and turn off the heating unit 42. Suitable controls for this purpose are well-known and form no part of the present invention. Accordingly, description of them is believed to be unnecessary and is omitted. Such controls may if desired be provided with a suitable control panel, for example as at 78 in FIG. 4a.
The mats 61 are non-woven, fibrous mats having a high surface area and are effective to deposit preferentially thereon the mineral salts that are created during and as a result of steam generation in the evaporation tank 36, rather than depositing them on other internal surfaces of the evaporation tank. It is presently preferred to use mats made of thermally bonded polyester fibers, especially polyethylene terephthalate fibers. A particularly preferred mat material is Filtermat Type P15/500S. available from Freudenberg Nonwovens L.P., Viledon Filter Division, of Chelmsford, MA. Filtermat Type P15/500S has an ASHRAE arrestance of 92%, an initial pressure loss at 300 fpm of 0.20 inches water gauge, a final pressure loss of 0.8 inches water gauge and a nominal depth or thickness of 3/4 inch.
In the preferred embodiment shown, the mats 61 (FIG. 6 and 7) are each disposed within a surrounding framework 81 having a handle 82 attached to its upper edge. The framework 81 is comprised of two sections 83 and 84 which are mirror images of one another. Each section is comprised of walls 86 that form a rectangular grid work, with diagonal braces 87. The sections 83 and 84 have opposed protrusions, for example elongate, top and bottom flanges 88, plug-like side baulks 90 and narrow intermediate pins 89 that abut against each other to provide a space between the grids. The fibrous mat(s) 61 are disposed in the space between the grids 86. Thus, the opposite sides of the mat 61 are supported by the grids 86. The flanges 88 and side baulks 90 border the mat 61 and the pins 89 penetrate the central portion of the mat 61 to fix the mat within the framework 81. The opposed top flanges 88 and side baulks 90 are fixed together, as by adhesive bonding. At least in one embodiment, an elongate, C-section, stainless steel clip 88A (FIGS. 6A and 7A) extends along and fixes together the bottom flanges 88 and protects the framework 81 from excessive heat produced by the adjacent heat source 42. The mat 61 is trapped between the sections 83 and 84 to thus form a unitary plate 61, 81. With the mat 61 installed in the tank 36, the framework 81 engages the opposed channels 64 to reliably support and fixedly locate the mat 61 with respect to the tank walls and adjacent mats 61.
In use, the plates 61, 81 are completely immersed in the water inside the evaporation tank and the mats 61 are effective to remove preferentially the water minerals that form during operation in the manner discussed above. When the collection efficiency of the fibers of the mats 61 diminishes, the drawer 21 can be opened so that the mats 61 can be removed and replaced by fresh mats. From time to time, it may be necessary to remove the entire evaporation tank for cleaning, repair or replacement.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.
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Mineral salts formed during steam generation are preferentially deposited on one or more non-woven, porous mats made of fiber-forming synthetic resin.
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FIELD OF THE INVENTION
[0001] The invention relates to an inflating device, and in particular to a device which is simple in structure and convenient to use and can realize manual inflation without requiring other tools.
BACKGROUND OF THE INVENTION
[0002] At present, there are many commercially available inflatable products, for example, inflatable toys, swim rings, inflatable pillows, inflatable mattresses and the like. For many small products, for example, inflatable toys and swim rings and the like, blowing with mouth is generally used. While for some large products, for example, inflatable mattresses, an electric inflating device is generally used. For products requiring blowing with mouth, it is not only labor-consuming but also unsanitary. Especially for some inflatable products used in public occasions, for example, inflatable pillows used in coaches, it is very unsanitary to blow with mouth while troublesome if they are inflated by other special instruments. Gas supply devices employing an electric compressor have a great volume and are inconvenient to use, and must be provided with a power supply. This results in great limitation to the inflation of products.
SUMMARY OF THE INVENTION
[0003] A technical problem required to be solved by the invention is to provide an inflating device, which has a small volume and a simple structure, is convenient to use without requiring any power supply, and allows for a simple deflating operation.
[0004] The invention may employ the following technical solutions.
[0005] An inflating device is provided, including a valve body and a gasbag, the valve body being provided with a gas inlet, a gas outlet and a gas storage chamber; the gas inlet has a gas intake valve device provided therein, and the gas outlet has a gas exhaust valve device provided therein; the gas storage chamber is communicated with the gasbag; and the gas inlet is communicated with the gas outlet through a chamber body of the valve body, and the gas storage chamber is communicated with the chamber body.
[0006] The invention may further make the following improvement to solve the problem:
[0007] As a further improvement, the gas exhaust valve device includes a gas exhaust valve base having a gas exhaust valve through hole provided therein, and a gas exhaust valve ring is provided in the gas exhaust valve through hole; and the gas exhaust valve ring is connected to a wall of the gas exhaust valve through hole by at least two gas exhaust valve supporting bars, and the gas exhaust valve base, the gas exhaust valve ring and the gas exhaust valve supporting bars are integrated.
[0008] A gas exhaust valve core passes through and is axially moveable in an inner hole of the gas exhaust valve ring; an annular protrusion, which is larger than the inner hole of the gas exhaust valve ring and radially faces outward, is provided on an outer end of the gas exhaust valve core, an inner end of the gas exhaust valve core is connected with a gas exhaust valve raised-bonnet which is larger than the inner hole of the gas exhaust valve ring, and the gas exhaust valve ring is positioned between the annular protrusion and the gas exhaust valve raised-bonnet; a gas exhaust valve spring is provided between the gas exhaust valve raised-bonnet and the gas exhaust valve ring, and the inner end of the gas exhaust valve core passes through the gas exhaust valve spring; and the outer end of the gas exhaust valve core faces outside the valve body, and the inner end of the gas exhaust valve core faces the chamber body of the valve body. As a further improvement, the outer end of the gas exhaust valve core is connected with a gas exhaust valve seal, an annular slope is provided at an outer end of the gas exhaust valve through hole, the shape and size of the annular slope are matched with those of the gas exhaust valve seal, and the gas exhaust valve spring enables the gas exhaust valve seal to seal the gas exhaust valve through hole after coming into close contact with the annular slope.
[0009] As a further improvement, the gas intake valve device includes a gas intake valve base having a gas intake valve through hole provided therein, and a gas intake valve ring is provided in the gas intake valve through hole; and the gas intake valve ring is connected to a wall of the gas intake valve through hole by at least two gas intake valve supporting bars, and the gas intake valve base, the gas intake valve ring and the gas intake valve supporting bars are integrated.
[0010] A gas intake valve core passes through and is axially movable in an inner hole of the gas intake valve ring; an annular protrusion, which is larger than the inner hole of the gas intake valve ring and radially faces outward, is provided on an outer end of the gas intake valve core, an inner end of the gas intake valve core is connected with a gas intake valve raised-bonnet which is larger than the inner hole of the gas intake valve ring, and the gas intake valve ring is positioned between the annular protrusion and the gas intake valve bonnet; a gas intake valve spring is provided between the gas intake valve raised-bonnet and the gas intake valve ring, and the inner end of the gas intake valve core passes through the gas intake valve spring; and the outer end of the gas intake valve core faces the chamber body of the valve body, and the inner end of the gas intake valve core faces outside the valve body.
[0011] As a further improvement, the outer end of the gas intake valve core is connected with a gas intake valve seal, an annular slope is provided at an outer end of the gas intake valve through hole, the shape and size of the annular slope are matched with those of the gas intake valve seal, and the gas intake valve spring enables the gas intake valve seal to seal the gas intake valve through hole after coming into close contact with the annular slope; and the outer end of the gas intake valve through hole faces the chamber body of the valve body, and the inner end of the gas intake valve through hole faces outside the valve body.
[0012] As a further improvement, the gas exhaust valve base is provided with a gas exhaust valve plug-in member, the gas intake valve base is provided with a gas intake valve plug-in member corresponding to and being coordinated with the gas exhaust valve plug-in member, and the gas exhaust valve plug-in member is in plug-in connection to the gas intake valve plug-in member.
[0013] As a further improvement, the gas exhaust valve through hole and the gas intake valve through hole share one axis; there is a gap between the gas exhaust valve raised-bonnet and the gas intake valve seal, the gas intake valve core can move the gas exhaust valve core through the gas intake valve seal to open the gas outlet when the gas intake valve core is pressed in a direction from the gas intake valve through hole to the chamber body of the valve body.
[0014] As a further improvement, an extension portion is provided on an inner side of the gas exhaust valve seal, and the extension portion is an elastomer; one end, far away from the gas exhaust value seal, of the extension portion is a distal end of the extension portion; and the distal end has a bump radially facing outward, the bump is positioned within a slot of the gas exhaust valve core after passing through the inner hole of the gas exhaust valve core, and the bump is larger than the inner hole of the gas exhaust valve core.
[0015] As a further improvement, an extension portion is provided on an inner side of the gas intake valve seal, and the extension portion is an elastomer; one end, far away from the gas inlet value seal, of the extension portion is a distal end of the extension portion; and the distal end has a bump radially facing outward, the bump is positioned within a slot of the gas intake valve core after passing through the inner hole of the gas intake valve core, and the bump is larger than the inner hole of the gas intake valve core.
[0016] As a further improvement, the valve body is constituted of a casing and a side bonnet connected to each other, the gas outlet is arranged within the casing, and the gas inlet is arranged on the side bonnet. As a further improvement, the gas exhaust valve base is provided with a round step, which is positioned within the casing and closely coordinated with an inner wall of the casing.
[0017] As a further improvement, the gasbag is positioned beside the valve body, and the gasbag is positioned beside a central axis of the gas outlet and a central axis of the gas inlet.
[0018] As a further improvement, the inner end of the gas intake valve through hole is detachably connected with a spring fixed lid.
[0019] The technical solutions have the following technical effects:
[0020] 1. In the invention, gas may be fed into an inflatable product by continually pressing with hands, without requiring electricity or blowing with mouth. The inflating device of the invention is convenient to operate, clean and sanitary. The invention has a small volume and is thus convenient to carry. The operation will not require any power supply.
[0021] 2. The inflating device of the invention has a simple structure and a small volume. The deflating operation is also easy and simple.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic structure diagram of the invention;
[0023] FIG. 2 is a schematic diagram of the invention viewed from another angle of view;
[0024] FIG. 3 is a schematic diagram of the invention when viewed from still another angle of view;
[0025] FIG. 4 is a schematic diagram along a line A-A of FIG. 3 ;
[0026] FIG. 5 is an exploded diagram of components;
[0027] FIG. 6 is an exploded diagram of the components when viewed from another angle of view;
[0028] FIG. 7 is a schematic diagram of a use state; and
[0029] FIG. 8 is a schematic diagram of another use state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The invention will be described below in detail by a specific embodiment.
Embodiment
[0031] As shown in FIGS. 1, 2, 3, 4, 5, 6, 7 and 8 , an inflating device is provided, including a valve body 1 and a gasbag 2 , the valve body 1 being provided with a gas inlet 101 , a gas outlet 102 and a gas storage chamber 103 ; the gas inlet 101 has a gas intake valve device 400 provided therein, and the gas outlet 102 has a gas exhaust valve device 300 provided therein; the gas storage chamber 103 is communicated with the gasbag 2 . The gas inlet 101 is communicated with the gas outlet 102 through a chamber body 104 of the valve body 1 , and the gas storage chamber 103 is communicated with the chamber body 104 . In this embodiment, the gasbag 2 is a sphere when in a natural state.
[0032] The gas exhaust valve device 300 includes a gas exhaust valve base 310 having a gas exhaust valve through hole 311 provided therein, and a gas exhaust valve ring 312 is provided in the gas exhaust valve through hole 311 ; the gas exhaust valve ring 312 is connected to a wall of the gas exhaust valve through hole 311 by at least two gas exhaust valve supporting bars 313 , and the gas exhaust valve base 310 , the gas exhaust valve ring 312 and the gas exhaust valve supporting bars 313 are integrated. In this embodiment, there are three gas exhaust valve supporting bars 313 . Of course, there may be two or more gas exhaust valve supporting bars 313 .
[0033] The gas exhaust valve core 320 passes through and may be axially moveable in an inner hole 314 of the gas exhaust valve ring 312 . An annular protrusion 312 , which is larger than the inner hole 314 of the gas exhaust valve ring and radially faces outward, is provided on an outer end of the gas exhaust valve core 320 , an inner end of the gas exhaust valve core 320 is connected with a gas exhaust valve raised-bonnet 322 which is larger than the inner hole 314 of the gas exhaust valve ring 312 , and the gas exhaust valve ring 312 is positioned between the annular protrusion 321 and the gas exhaust valve raised-bonnet 322 ; a gas exhaust valve spring 330 is provided between the gas exhaust valve raised-bonnet 322 and the gas exhaust valve ring 312 , and the inner end of the gas exhaust valve core 320 passes through the gas exhaust valve spring 330 ; and the outer end of the gas exhaust valve core 320 faces outside the valve body 1 , and the inner end of the gas exhaust valve core 320 faces the chamber body 104 of the valve body 1 .
[0034] The outer end of the gas exhaust valve core 320 is connected with a gas exhaust valve seal 340 , an annular slope 315 is provided at an outer end of the gas exhaust valve through hole 311 , the shape and size of the annular slope 315 are matched with those of the gas exhaust valve seal 340 , and the gas exhaust valve spring 330 enables the gas exhaust valve seal 340 to seal the gas exhaust valve through hole 311 after coming into close contact with the annular slope 315 . In this embodiment, the gas exhaust valve seal is, just like a conventional seal, made of elastic plastic.
[0035] The gas intake valve device 400 includes a gas intake valve base 410 having a gas intake valve through hole 411 provided therein, and a gas intake valve ring 412 is provided in the gas intake valve through hole 411 ; and the gas intake valve ring 412 is connected to a wall of the gas intake valve through hole 411 by at least two gas intake valve supporting bars 413 , and the gas intake valve base 410 , the gas intake valve ring 412 and the gas intake valve supporting bars 413 are integrated.
[0036] A gas intake valve core 420 passes through and may be axially movable in an inner hole 414 of the gas intake valve ring 412 ; an annular protrusion 421 , which is larger than the inner hole 414 of the gas intake valve ring 412 and radially faces outward, is provided on an outer end of the gas intake valve core 420 , an inner end of the gas intake valve core 420 is connected with a gas intake valve raised-bonnet 422 which is larger than the inner hole 414 of the gas intake valve ring 412 , and the gas intake valve ring 412 is positioned between the annular protrusion 421 and the gas intake valve bonnet 422 . A gas intake valve spring 430 is provided between the gas intake valve raised-bonnet 422 and the gas intake valve ring 412 , and the inner end of the gas intake valve core 420 passes through the gas intake valve spring 430 ; and the outer end of the gas intake valve core 420 faces the chamber body 104 of the valve body, and the inner end of the gas intake valve core 420 faces outside the valve body 1 .
[0037] The outer end of the gas intake valve core 420 is connected with a gas intake valve seal 440 , an annular slope 415 is provided at an outer end of the gas intake valve through hole 411 , the shape and size of the annular slope 415 are matched with those of the gas intake valve seal 440 , and the gas intake valve spring enables the gas intake valve seal 440 to seal the gas intake valve through hole 411 after coming into close contact with the annular slope 415 ; and the outer end of the gas intake valve through hole 411 faces the chamber body 104 of the valve body 1 , and the inner end of the gas intake valve through hole 411 faces outside the valve body 1 . In this embodiment, the gas intake valve seal is, just like a conventional seal, made of plastic.
[0038] The inner end of the gas intake valve through hole 411 is connected with a lid 5 which is used for preventing the gas within an object to be inflated from leaking.
[0039] The gas exhaust valve through hole 311 and the gas intake valve through hole 411 share one axis; there is a gap between the gas exhaust valve raised-bonnet 322 and the gas intake valve seal 440 , the gas intake valve core 420 can move the gas exhaust valve core 320 through the gas intake valve seal 440 to open the gas outlet when the gas intake valve core 420 is pressed in a direction from the gas intake valve through hole 411 to the chamber body of the valve body.
[0040] The valve body 1 is constituted of a casing 105 and a side bonnet 106 connected to each other, the gas outlet 102 is arranged within the casing 105 , and the gas inlet 101 is arranged on the side bonnet 106 .
[0041] The gas exhaust valve base 310 is provided with a round step 316 which is positioned within the casing 105 and closely fitted with an inner wall of the casing 105 .
[0042] The gas exhaust valve base 310 is provided with a gas exhaust valve plug-in member 7 , the gas intake valve base 320 is provided with a gas intake valve plug-in member 8 corresponding to and being coordinated with the gas exhaust valve plug-in member 7 , and the gas exhaust valve plug-in member is in plug-in connection to the gas intake valve plug-in member 8 ; and a hole 81 is formed on the gas intake valve plug-in member 8 , and the gas exhaust valve plug-in member is inserted into the hole 81 of the gas intake valve plug-in member to realize the plug-in connection. In this way, it is conducive to positioning and fixing the two bases.
[0043] As a further improvement, an extension portion 341 is provided on an inner side of the gas exhaust valve seal 340 , and the extension portion 341 is an elastomer; one end, far away from the gas exhaust value seal 340 , of the extension portion 341 is a distal end of the extension portion 341 ; and the distal end has a bump 342 radially facing outward, the bump 342 is positioned within a slot 324 of the gas exhaust valve core after passing through the inner hole 323 of the gas exhaust valve core 320 , and the bump 342 is larger than the inner hole 323 of the gas exhaust valve core 320 . With such a structure, the connection between the gas exhaust valve seal and the gas exhaust valve core is realized, and the assembly and disassembly are convenient and fast.
[0044] An extension portion 441 is provided on an inner side of the gas intake valve seal 440 , and the extension portion 441 is an elastomer; one end, far away from the gas intake value seal 440 , of the extension portion 441 is a distal end of the extension portion 441 ; and the distal end has a bump 442 radially facing outward, the bump 442 is positioned within a slot 424 of the gas intake valve core after passing through the inner hole 423 of the gas intake valve core 420 , and the bump 442 is larger than the inner hole 423 of the gas intake valve core 423 . With such a structure, the connection between the gas intake valve seal and the gas intake valve core is realized, and the assembly and disassembly are convenient and fast.
[0045] The gasbag 2 is positioned beside the valve body 1 , and the gasbag 2 is positioned beside a central axis of the gas outlet 102 and a central axis of the gas inlet 101 .
[0046] FIG. 7 and FIG. 8 are schematic diagrams of a use state when gas is being fed. The object 9 is an object to be inflated. During the use, the gas exhaust valve base 310 is connected to the object 9 to be inflated in a sealed manner.
[0047] During the inflation, the lid 5 may be opened, the gasbag 2 is pressed and the gas pressure inside the chamber body 104 is thus increased, and the gas intake valve seal 440 firmly presses the annular slope 415 due to the gas pressure, so that the gas inlet 101 is kept closed; and the gas pressure acts on the gas exhaust valve spring fixing lid 322 , so that the body of the gas exhaust valve core 320 moves outward against the elasticity of the gas exhaust valve spring 330 . In this way, a gap is formed between the gas exhaust valve seal 340 and the annular slope 315 , and the gas in the gasbag 2 is fed into the object to be inflated from the gap after passing through the gas storage chamber 103 , the chamber body 104 and the gas outlet 102 . The gasbag 2 expands outward when it is released. At this time, the negative pressure effect occurs, the gas exhaust valve seal 340 and the annular slope 315 are firmly closed, and the gas outlet 102 is closed; and the gas intake valve core 420 moves towards the gas exhaust valve core 320 against the elasticity of the gas intake valve spring 430 due to the ambient pressure. At this time, a gap is formed between the gas intake valve seal 440 and the annular slop 415 , and the external gas enters the chamber body 104 from the gas inlet 101 and then enters the gasbag 2 after passing through the gas storage chamber 103 until the gasbag 2 expands to the natural state. Then, the gasbag 2 is pressed again, and the gas will be fed into the object to be inflated. Gas is continuously fed by repeating this process. The inflating device of the invention has a small volume and a simple structure, and is convenient to use. The manual operation is easy.
[0048] To deflate an object, the gas intake valve spring fixing lid 422 is pressed, so that the gas intake valve core moves towards the gas exhaust valve core 320 against the elasticity of the gas intake valve spring 430 . At this time, a gap is formed between the gas intake valve seal 440 and the annular slope 415 . Meanwhile, the gas intake valve seal 440 bears against the gas exhaust valve spring fixing lid 322 , so that the gas exhaust valve core 320 moves outward against the elasticity of the gas exhaust valve spring 330 . In this way, a gap is formed between the gas exhaust valve seal 340 and the annular slope 315 , and the gas in the object to be deflated comes out from the gap after passing through the gas outlet and the gas inlet, the deflating is thus realized. The deflating is convenient, the manual control is simple, the manufacture is easy, and it is convenient to adjust the gas pressure of inflatable products and to deflate the inflatable products.
[0049] What described above is merely a preferred embodiment of the invention and not intended to limit the invention, and any modifications, equivalent replacements and improvements made within the spirit and principle of the invention should fall into the protection scope of the invention.
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An inflating device comprises a valve body and a gasbag, the valve body being provided with a gas inlet, a gas outlet and a gas storage chamber; the gas inlet has a gas intake valve device provided therein, and the gas outlet has a gas exhaust valve device provided therein; the gas storage chamber is communicated with the gasbag; and the gas inlet is communicated with the gas outlet through a chamber body of the valve body, and the gas storage chamber is communicated with the chamber body. In the invention, gas can be fed into an inflatable product by continually pressing with hands, without requiring electricity or blowing with mouth. The inflating device of the invention is convenient to operate, clean and sanitary. The inflating device of the invention has a small volume and is thus convenient to carry.
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BACKGROUND OF THE INVENTION
Many basses, vintage guitars, and guitars with more than one neck (doublenecks), have necks that are heavier than the instrument bodies they are joined to. In these instances, when a player of an unbalanced instrument releases both hands from the instrument, they lose control over the instrument. The result is the neck of the instrument “drops” or “dives”. Attention dedicated to this problem has focused primarily on what the neck is doing: dropping in height. However, we concerned owners of these unbalanced guitars and basses were focusing on the wrong end of the instrument. We looked endlessly at the guitar or bass “neck”, and its heavy head stock and tuners, and wondered how we could prevent it from “falling”. No adequate solution has ever presented itself by looking at and focusing on “the neck”. But what else was there to look at? As soon as I asked that question, the current embodiment of this invention slowly came into view, and the creation of The Neckdive Strap began to take form. What if we turn the problem “on its head”, and start thinking in “opposites”? If something is “falling”, it stands to reason that somewhere else, something is “rising”. It then stands to reason that as the neck of the instrument is “falling” in height, the opposite end of the instrument is “rising”. Upon observing this phenomenon, it became apparent that if an instrument body's furthest and opposite end-point from the neck could be prevented from rising, the neck would no longer drop, or “dive”, when a player released both hands from the instrument. The standard shoulder strap end pin ( FIG. 1 , # 3 ) was observed to be the optimal location for some kind of strap to prevent this “rise”. Upon further investigation, this strap could use a player's leg to provide the anchor point. A prototype was made from an old pant belt, and accomplished the sought after results. The current embodiment has added features of a quick release leg buckle ( 4 ), two adjustable buckles for leg girth ( 4 ) and strap length ( 5 ), and an option for using an off the shelf strap lock to connect the strap end hole ( 3 a ) to the instrument end pin ( 3 ).
SUMMARY OF THE INVENTION
The Neckdive Strap overcomes the deficiencies of prior support systems by focusing attention not on the neck of the instrument, but on the opposite end of the guitar or bass, specifically, the shoulder strap end pin. As the neck drops in height, the end pin on the opposite side of the guitar rises. Preventing this rise is the purpose of the current invention. The Neckdive Strap uses the players leg as the anchor point, and attaches to the end pin of any instrument that is played in a standing position with a standard guitar or bass shoulder strap. The unique embodiment and configuration of the prior art [Strap ( 1 , 6 , 7 ), buckles ( 4 , 5 ), leather end ( 2 )] used in this current invention, for the specific purposes stated, namely, its use to eliminate the long-standing problem encountered by guitarists and bassists of the condition known as “neck-dive”, demonstrates a unique use and assembly of those individual components, and therefore qualifies this unique invention and all of its claims, for patent protection.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is a side view of a player wearing the leg support strap, connected to the same end pin of a guitar that a standard shoulder strap is attached to.
FIG. 2 is an overhead view of the strap showing all its parts, buckles, and how it is assembled. The large loop encircles the upper thigh of the player's leg ( 1 ), is joined by a quick-release single adjustable buckle, and continues ( 7 ) into another adjustable buckle ( 5 ) with a leather strap end sewn into its end ( 2 ).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Shown in FIG. 1 is a side view illustration of a player with a typical neck-heavy instrument, a doubleneck guitar ( 9 ), with a standard shoulder strap ( 8 ) attached to the endpin ( 3 ) of the guitar. Attached to this same endpin ( 3 ) is the leg-encircling Neckdive Strap ( 1 THRU 7 ). The leg-encircling portion of the strap ( 1 ) is connected by a quick-release single adjustable buckle ( 4 ). This adjustable buckle provides two functions: it allows the strap to be easily attached or detached from around the player's upper thigh portion of the leg, and it adjusts the girth of the strap so that it can fit any person's width or leg circumference. The strap continues out of the adjustable portion of this first buckle ( 4 ) and creates the length portion of the strap ( 7 —partially hidden by 6 , but fully viewable in FIG. 2 ). This “length” portion of the strap will, in most cases, be relatively short, due to the close proximity of the leg to the guitar end pin. This length is fully adjustable, on the fly, by the next buckle ( 5 ). The continuous length of strap is now threaded through the second adjustable buckle ( 5 ), which has as part of its features a loop end. The remainging strap, used as a length of strap for easily making final neck height adjustments to the guitar, hangs down from the second buckle, and is easily accessible by the player. Attached to the loop portion of this buckle is a leather strap end ( 2 ), with a hole punched into it ( 3 a ), which is then placed onto the same end pin ( 3 ) as the previously mentioned shoulder strap ( 8 ).
FIG. 2 illustrates a side-overhead view of the preferred embodiment of the neckdive-prevention strap. A single, continuous strap ( 1 , 7 , 6 ) is threaded through two different buckles ( 4 , 5 ), and has a leather strap end attached to the loop end of the second buckle ( 5 ). Strap portion ( 1 ) forms a large loop which encircles the players leg, and is attachable and detachable by use of the quick release buckle ( 4 ). The quick release buckle also has an adjustment feature to it, which allow the player to size this portion of the strap to fit the circumference of his or her leg. The strap then continues out of the adjustment portion of this first buckle ( 4 ) and creates the length portion of the strap ( 7 ). This length portion determines the distance of the strap from the leg to the instrument's end pin ( 3 in FIG. 1 ), and serves to allow the player to adjust the angle of the neck(s) of the instrument to the desired height. This adjustment is achieved by the implementation of a second buckle ( 5 ), which the remaining portion of the single, continuous strap is threaded through, leaving the remaining strap to hang down, within reach of the player, for easy access in case on the fly adjustments are desired. Also attached to this second buckle ( 5 ), on its opposite end, where there is a loop, is a leather strap piece, or leather strap end ( 2 ), with a hole punched into it ( 3 a ), which attaches to the end pin ( 3 in FIG. 1 ) of the neck heavy instrument ( 9 in FIG. 1 ).
In use, the player first wants to adjust the leg portion of the strap so it fits comfortably and securely, around the circumference of their leg. This is done by releasing the leg buckle's ( 4 ) quick-release lock, wrapping the leg portion of the strap around the leg, rejoining the buckle, and then pulling or pushing the strap through the quick-release buckle's adjustable portion. Once a suitable adjustment is made, the strap is unbuckled, and the player puts the guitar or bass on. Once the instrument is on, the player attaches the strap back onto the leg, and then places the strap's leather strap end ( 2 ) onto the same end pin that the shoulder strap ( 8 — FIG. 1 ) is connected to, on the back end of the body of the instrument ( 3 — FIG. 1 ) The final adjustment of the angle of the instrument, or height of the neck, is made now, whether by pulling on the excess length of strap ( 6 ) to shorten the length of 7 , or by pulling up on the buckle “tab” ( 5 ), lengthening 7 and therefore lowering the height of the neck, or decreasing the angle of the instrument. Once the strap is attached to the instrument end pin, the instrument is held firmly in place, and the neck cannot move down, or “dive. It can still move up, or out, or towards the player's body, retaining almost complete freedom of movement of the instrument as before. The problem however, of the instrument taking a “dive”, has been eliminated.
While the present invention has been described and illustrated with respect to the preferred embodiment, it will be appreciated that variations of the invention in regards to the materials used, whether they be nylon, plastic, leather, metal, or polyester, cloth, suede, or any other type or makeup of the materials presented in this current embodiment, may be made without departing from the scope of the invention which is defined in the appending claims.
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A leg strap, that connects a guitar or bass player's upper thigh to the shoulder-strap end pin, located on the body of a guitar or bass, for the purpose of supporting the instrument in a stationary playing position, eliminating an adverse condition known as “neck-dive”, which is the tendency in unbalanced and neck-heavy instruments for the neck-portion of the instrument to drop in a downward direction when both hands are taken off the instrument.
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FIELD OF THE INVENTION
The present invention relates to a pneumatic module for a surgical machine and more particularly to a pneumatic module designed to provide power to a vitrector.
BACKGROUND OF THE INVENTION
Vitreo-retinal procedures include a variety of surgical procedures performed to restore, preserve, and enhance vision. Vitreo-retinal procedures are appropriate to treat many serious conditions of the back of the eye. Vitreo-retinal procedures treat conditions such as age-related macular degeneration (AMD), diabetic retinopathy and diabetic vitreous hemorrhage, macular hole, retinal detachment, epiretinal membrane, CMV retinitis, and many other ophthalmic conditions.
The vitreous is a normally clear, gel-like substance that fills the center of the eye. It makes up approximately ⅔ of the eye's volume, giving it form and shape before birth. Certain problems affecting the back of the eye may require a vitrectomy, or surgical removal of the vitreous.
A vitrectomy may be performed to clear blood and debris from the eye, to remove scar tissue, or to alleviate traction on the retina. Blood, inflammatory cells, debris, and scar tissue obscure light as it passes through the eye to the retina, resulting in blurred vision. The vitreous is also removed if it is pulling or tugging the retina from its normal position. Some of the most common eye conditions that require vitrectomy include complications from diabetic retinopathy such as retinal detachment or bleeding, macular hole, retinal detachment, pre-retinal membrane fibrosis, bleeding inside the eye (vitreous hemorrhage), injury or infection, and certain problems related to previous eye surgery.
The retinal surgeon performs a vitrectomy with a microscope and special lenses designed to provide a clear image of the back of the eye. Several tiny incisions just a few millimeters in length are made on the sclera. The retinal surgeon inserts microsurgical instruments through the incisions such as a fiber optic light source to illuminate inside the eye, an infusion line to maintain the eye's shape during surgery, and instruments to cut and remove the vitreous.
In a vitrectomy, the surgeon creates three tiny incisions in the eye for three separate instruments. These incisions are placed in the pars plana of the eye, which is located just behind the iris but in front of the retina. The instruments which pass through these incisions include a light pipe, an infusion port, and the vitrectomy cutting device. The light pipe is the equivalent of a microscopic high-intensity flashlight for use within the eye. The infusion port is required to replace fluid in the eye and maintain proper pressure within the eye. The vitrector, or cutting device, works like a tiny guillotine, with an oscillating microscopic cutter to remove the vitreous gel in a controlled fashion. This prevents significant traction on the retina during the removal of the vitreous humor.
The surgical machine used to perform a vitrectomy and other surgeries on the posterior of the eye is very complex. Typically, such an ophthalmic surgical machine includes a main console to which the numerous different tools are attached. The main console provides power to and controls the operation of the attached tools.
The attached tools typically include probes, scissors, forceps, illuminators, vitrectors, and infusion lines. Each of these tools is typically attached to the main surgical console. A computer in the main surgical console monitors and controls the operation of these tools. These tools also get their power from the main surgical console. Some of these tools are electrically powered while others are pneumatically powered.
In order to provide pneumatic power to the various tools, the main surgical console has a pneumatic or air distribution module. This pneumatic module conditions and supplies compressed air or gas to power the tools. Typically, the pneumatic module is connected to a cylinder that contains compressed gas. The pneumatic module must provide the proper gas pressure to operate the attached tools properly.
In particular, one tool, a vitrector, is utilized to cut the vitreous for removal during a vitrectomy. Vitrectors operate at different speeds. Generally, the faster a vitrector operates, the quicker a vitrectomy can be performed. It would be desirable to have a pneumatic module to provide power to a vitrector to enable fast operation thereof with a minimal number of parts.
SUMMARY OF THE INVENTION
In one embodiment consistent with the principles of the present invention, the present invention is a system for providing pneumatic power to a vitrector. The system includes first and second output ports, an output valve, an isolation valve, and three manifolds. The first and second output ports provide pressurized gas to power a vitrector. The output valve alternately provides pressurized gas to the first and second output ports. The isolation valve provides pressurized gas to the output valve. Two manifolds fluidly connect the output valve to the first and second output ports. A third manifold fluidly connects the isolation valve to the output valve. When the isolation valve provides pressurized gas to the output valve, the output valve operates at a high rate of speed to alternately provide pressurized gas to the first and second output ports thereby powering the vitrector.
In another embodiment consistent with the principles of the present invention, the present invention is a system for providing pneumatic power to a vitrector. The system includes first and second output ports, an output valve, an isolation valve, a controller, and three manifolds. The first and second output ports provide pressurized gas to power a vitrector. The output valve alternately provides pressurized gas to the first and second output ports. The isolation valve provides pressurized gas to the output valve. The output valve is located between the isolation valve and the first and second output ports. The controller controls the operation of the isolation valve and the output valve. Two manifolds fluidly connect the output valve to the first and second output ports. A third manifold fluidly connects the isolation valve to the output valve. When the isolation valve allows pressurized gas to flow to the output valve, the output valve operates at a high rate of speed to alternately provide pressurized gas to the first and second output ports thereby powering the vitrector.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed. The following description, as well as the practice of the invention, set forth and suggest additional advantages and purposes of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
FIG. 1 is a block diagram of a pneumatically-powered ophthalmic surgery machine according to an embodiment of the present invention.
FIG. 2 is a schematic of a pneumatic system for a pneumatically powered vitrectomy machine according to an embodiment of the present invention.
FIG. 3 is a schematic of a controller, valve, and transducer portion of a pneumatic system for a pneumatically powered vitrectomy machine according to an embodiment of the present invention.
FIG. 4 is a perspective view of a pneumatic system according to an embodiment of the present invention.
FIG. 5 is a bottom perspective view of a pneumatic system according to an embodiment of the present invention.
FIG. 6 is a top view of a pneumatic system according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is now made in detail to the exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts.
FIG. 1 is a block diagram of a pneumatically powered ophthalmic surgical machine according to an embodiment of the present invention. In FIG. 1 , the machine includes gas pressure monitor system 110 , proportional controller 120 , proportional controller 130 , and tools 140 , 150 , 160 , and 170 . The tools 140 , 150 , 160 , and 170 can be, for example, scissors, vitrectors, forceps, and injection or extraction modules. Other tools may also be employed with the machine of FIG. 1 .
As shown in FIG. 1 , gas pressure monitor system 110 is fluidly coupled via a manifold to proportional controllers 120 and 130 . A single manifold may connect gas pressure monitor system 110 to proportional controllers 120 and 130 , or two separate manifolds may connect gas pressure monitor system 110 to proportional controller 120 and proportional controller 130 , respectively.
In operation, the pneumatically powered ophthalmic surgery machine of FIG. 1 operates to assist a surgeon in performing various ophthalmic surgical procedures, such as a vitrectomy. A compressed gas, such as nitrogen, provides the power for tools 140 , 150 , 160 , and 170 . The compressed gas passes through gas pressure monitor system 110 , through one or more manifolds to proportional controllers 120 and 130 , and through additional manifolds and/or tubing to tools 140 , 150 , 160 , and 170 .
Gas pressure monitor system 110 functions to monitor the pressure of compressed gas from a gas source as it enters the machine. Proportional controllers 120 and 130 serve to distribute the compressed gas received from gas pressure monitor system 110 . Proportional controllers 120 and 130 control the pneumatic power delivered to tools 140 , 150 , 160 , and 170 . Various valves, manifolds, and tubing are used to direct compressed gas from gas pressure monitor system 110 , through proportional controllers 120 and 130 , and to tools 140 , 150 , 160 , and 170 . This compressed gas actuates cylinders, for example, in tools 140 , 150 , 160 , and 170 .
FIG. 2 is a schematic of a pneumatic system for a pneumatically powered vitrectomy machine according to an embodiment of the present invention. In FIG. 2 , the pneumatic system includes isolation valve 205 , output valve 210 , pressure transducers 215 and 220 , mufflers 225 and 230 , venting manifolds 235 and 240 , manifolds 245 , 250 , 255 , and 260 , and output ports A and B.
Venting manifold 235 fluidly connects isolation valve 205 to muffler 230 . Manifold 245 is also fluidly connected to isolation valve 205 . Isolation valve 205 is fluidly connected to output valve 210 by manifold 250 . Venting manifold 240 fluidly connects output valve 210 to muffler 225 . Manifold 255 fluidly connects output valve 210 to output port A. Manifold 260 fluidly connects output valve 210 to output port B. Pressure transducer 215 is fluidly connected to manifold 255 . Likewise, pressure transducer 220 is fluidly connected to manifold 260 .
In the embodiment of FIG. 2 , isolation valve 205 is a standard two-way valve. As is commonly known, the valve has a solenoid that operates to move the valve to one of the two positions depicted in FIG. 2 . As shown, the valve is in a venting position. Pressurized gas can pass from manifold 250 , through isolation valve 205 , through venting manifold 235 , and out of muffler 230 . In the other position, isolation valve 205 allows pressurized gas to pass from manifold 245 , through isolation valve 205 , and into manifold 250 where it can provide power to the vitrector (not shown). Isolation valve 205 is controlled by a controller (not shown).
Output valve 210 is a standard four-way valve. As is commonly known, the valve has a solenoid that operates to move the valve to one of the two positions depicted in FIG. 2 . As shown in FIG. 2 , the valve is in a position to provide pressurized gas to output port A, and to vent pressurized gas from output port B. In this position, pressurized gas can pass from manifold 250 , through output valve 210 , through manifold 255 , and to output port A where the pressurized gas provides pneumatic power to a vitrector (not shown). Pressurized gas in manifold 260 can pass through output valve 210 , venting manifold 240 , and muffler 225 where it is exhausted to the atmosphere. In the other position, output valve 210 allows pressurized gas to pass from manifold 250 , through output valve 210 , through manifold 260 , and to output port B where the pressurized gas provides pneumatic power to a vitrector (not shown). Pressurized gas in manifold 255 can pass through output valve 210 , venting manifold 240 , and muffler 225 where it is exhausted to the atmosphere. Output valve 210 is controlled by a controller (not shown).
The vitrector (not shown) that is attached to output ports A and B acts as a cutting device. The cutter is moved by a cylinder that in turn is moved by pressurized gas. The cylinder oscillates as pressurized gas is alternately directed to output ports A and B. Such a vitrectomy device is designed to operate at about 5,000 cuts per minute.
Pressure transducers 215 and 220 operate to read an atmospheric pressure of the gas contained in manifolds 255 and 260 , respectfully. In other words, pressure transducer 215 reads the pressure of the compressed gas that is adjacent to it in manifold 255 . Likewise, pressure transducer 220 reads the pressure of the compressed gas that is adjacent to it in manifold 260 . In the embodiment of FIG. 2 , pressure transducers 215 and 220 are common pressure transducers. Pressure transducers 215 and 220 are capable of reading pressure of a compressed gas and sending an electrical signal containing information about the pressure of the compressed gas to a controller (not shown).
Manifolds 235 , 240 , 245 , 250 , 255 , and 260 are all configured to carry compressed gas. In the embodiment of FIG. 2 , these manifolds are machined out of a metal, such as aluminum. These manifolds are air tight, contain various fittings and couplings, and are designed to withstand relatively high gas pressures. These manifolds may be manufactured as individual pieces or they may be manufactured as a single piece. For example, manifolds 235 , 240 , 245 , 250 , 255 , and 260 may be machined from a single piece of aluminum.
Mufflers 225 and 230 are common mufflers designed to suppress the noise made by escaping gas. These mufflers are typically cylindrical in shape.
In operation, pressurized gas is directed alternately to output ports A and B to operate the vitrector. Isolation valve 205 is operated in a position that allows pressurized gas to pass from manifold 245 , through isolation valve 205 , and into manifold 250 . Output valve 210 is alternated between its two positions very rapidly to provide pressurized gas to output ports A and B. In one position, pressurized gas can pass from manifold 250 , through output valve 210 , through manifold 255 , and to output port A where the pressurized gas provides pneumatic power to a vitrector (not shown). Pressurized gas in manifold 260 can pass through output valve 210 , venting manifold 240 , and muffler 225 where it is exhausted to the atmosphere. In the other position, output valve 210 allows pressurized gas to pass from manifold 250 , through output valve 210 , through manifold 260 , and to output port B where the pressurized gas provides pneumatic power to a vitrector (not shown). Pressurized gas in manifold 255 can pass through output valve 210 , venting manifold 240 , and muffler 225 where it is exhausted to the atmosphere.
In this manner, pressurized gas is provided to output port A while pressurized gas in manifold 260 is allowed to vent through a venting port to which muffler 225 is attached. Likewise, pressurized gas is provided to output port B while pressurized gas in manifold 255 is allowed to vent through a venting port to which muffler 225 is attached. Due to the quick response of the output valve selected, pressurized gas can be alternated very quickly between manifolds 255 and 260 . This allows the vitrector (not shown) to operate at very high cut rates of about 5,000 cuts per minute.
FIG. 3 is a schematic of a controller, valve, and transducer portion of a pneumatic system for a pneumatically powered vitrectomy machine according to an embodiment of the present invention. In FIG. 3 , controller 300 and interfaces 305 , 310 , 315 , and 320 are depicted along with isolation valve 205 , output valve 210 , and pressure transducers 215 and 220 .
In the embodiment of FIG. 3 , controller 300 receives pressure information from pressure transducers 215 and 220 via interfaces 305 and 310 , respectively. In this manner, pressure transducer 215 is electrically coupled to controller 300 via interface 305 , and pressure transducer 220 is electrically coupled to controller 300 via interface 310 . Controller sends control signals to isolation valve 205 and output valve 210 via interfaces 315 and 320 , respectively.
Controller 300 is typically an intergraded circuit capable of performing logic functions. In this manner, controller 300 is in the form of a standard integrated circuit package with power, input, and output pins. In various embodiments, controller 300 is a valve controller or a targeted device controller. In such a case, controller 300 performs specific control functions targeted to a specific device, such as a valve. In other embodiments, controller 300 is a microprocessor. In such a case, controller 300 is programmable so that it can function to control valves as well as other components of the machine. In other cases, controller 300 is not a programmable microprocessor, but instead is a special purpose controller configured to control different valves that perform different functions.
Controller 300 is configured to receive signals from pressure transducer 215 via interface 305 and from pressure transducer 220 via interface 310 . These signals, for example, correspond to readings of gas pressure in manifolds 255 and 260 , respectively. Controller 300 is also configured to send output signals via interfaces 315 and 320 to isolation valve 205 and output valve 210 , respectively. These output signals allow controller 300 to control the operation of isolation valve 205 and output valve 210 .
Interfaces 305 and 310 are designed to carry signals from pressure transducers 215 and 220 to controller 300 . In this case, interfaces 305 and 310 are common electrical conductors such as wires, buses, traces, or the like. Likewise, interfaces 315 and 320 carry signals from controller 300 to isolation valve 205 and output valve 210 . Interfaces 305 , 310 , 315 , and 320 may be one or more wires, buses, traces, or the like designed to carry electrical or data signals.
FIG. 4 is a perspective view of a pneumatic system according to an embodiment of the present invention. The pneumatic system of FIG. 4 depicts isolation valve 205 , output valve 210 , mufflers 225 and 230 , and output ports A and B. These various components are connected via a series of manifolds machined out of a single piece of aluminum. The characteristics and operation of the pneumatic system of FIG. 4 is similar to that previously described with respect to FIGS. 2 and 3 .
FIG. 5 is a bottom perspective view of a pneumatic system according to an embodiment of the present invention. The pneumatic system of FIG. 5 depicts pressure transducers 215 and 220 , mufflers 225 and 230 , manifolds 235 , 245 , 255 , and 260 , and output ports A and B. These various manifolds are machined out of a single piece of aluminum. The characteristics and operation of the pneumatic system of FIG. 5 is similar to that previously described with respect to FIGS. 2 and 3 .
FIG. 6 is a top view of a pneumatic system according to an embodiment of the present invention. The pneumatic system of FIG. 6 depicts mufflers 225 and 230 , manifolds 235 , 240 , 245 , 250 , 255 , and 260 , and output ports A and B. These various manifolds are machined out of a single piece of aluminum. The characteristics and operation of the pneumatic system of FIG. 6 is similar to that previously described with respect to FIGS. 2 and 3 .
From the above, it may be appreciated that the present invention provides an improved system for providing pneumatic power to a vitrector. The present invention enables the rapid provision of compressed gas to a vitrector with a minimal number of components. The present invention is illustrated herein by example, and various modifications may be made by a person of ordinary skill in the art.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
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A system for providing pneumatic power to a vitrector includes first and second output ports, an output valve, an isolation valve, and three manifolds. The first and second output ports provide pressurized gas to power a vitrector. The output valve alternately provides pressurized gas to the first and second output ports. The isolation valve provides pressurized gas to the output valve. Two manifolds fluidly connect the output valve to the first and second output ports. A third manifold fluidly connects the isolation valve to the output valve. When the isolation valve provides pressurized gas to the output valve, the output valve operates at a high rate of speed to alternately provide pressurized gas to the first and second output ports thereby powering the vitrector.
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FIELD OF THE INVENTION
The invention relates to radio navigation in general, and, more particularly, to generating an accurate estimate of the location of a wireless terminal despite apparently reasonable but misleading or erroneous data.
BACKGROUND
FIG. 1 depicts a diagram of the salient components of wireless telecommunications system 100 in accordance with the prior art. Wireless telecommunications system 100 comprises: wireless terminal 101 , cellular base stations 102 - 1 , 102 - 2 , and 102 - 3 , Wi-Fi base stations 103 - 1 and 103 - 2 , wireless switching center 111 , assistance server 112 , location client 113 , and Global Positioning System (“GPS”) constellation 121 . Wireless telecommunications system 100 provides wireless telecommunications service to all of geographic region 120 , in well-known fashion.
The salient advantage of wireless telecommunications over wireline telecommunications is the mobility that is afforded to the user of the wireless terminal. On the other hand, the salient disadvantage of wireless telecommunications lies in that fact that because the wireless terminal is mobile, an interested party might not be able to readily ascertain the location of the wireless terminal.
Such interested parties might include both the user of the wireless terminal and remote parties. There are a variety of reasons why the user of a wireless terminal might be interested in knowing his or her location. For example, the user might be interested in telling a remote party where he or she is or the user might seek advice in navigation.
In addition, there are a variety of reasons why a remote party might be interested in knowing the location of the user. For example, the recipient of an 9-1-1 emergency call from a user might be interested in knowing the location of the wireless terminal so that emergency services vehicles can be dispatched to the user.
There are many techniques in the prior art for estimating the location of a wireless terminal. The common theme to these techniques is that location of the wireless terminal is estimated based on the electromagnetic (e.g., radio, etc.) signals—in one form or another—that are processed (i.e., transmitted or received) by the wireless terminal.
In accordance with one family of techniques, the location of a wireless terminal is estimated based on the transmission range of the base stations with which it is communicating. Because the range of a base station is known to be N meters, this family of techniques provides an estimate for the location that is generally accurate to within N meters. A common name for this family of techniques is “cell identification” or “cell ID.”
There are numerous tricks that can be made to the basic cell ID technique to improve the accuracy of the estimate for the location, and numerous companies like Ericsson, Qualcomm, and Google each tout their own flavor. The principal disadvantage of the family of cell ID techniques is that there are many applications for which the accuracy of the estimate for the location it generates is insufficient.
In accordance with a second family of techniques, the location of a wireless terminal is estimated by analyzing the angle of arrival or time of arrival of the signals transmitted by the wireless terminal. A common, if somewhat inaccurate, name for this family of techniques is called “triangulation.”
There are numerous tricks that can be made to the basic triangulation technique to improve the accuracy of the estimate for the location, and numerous companies like TruePosition each tout their own flavor. The principal disadvantage of the triangulation techniques is that there are many applications for which the accuracy of the estimate for the location it generates is insufficient.
In accordance with a third family of techniques, the location of a wireless terminal is estimated by a receiver in the wireless terminal that receives signals from satellites in orbit. A common name for this family of techniques is “GPS.”
There are numerous tricks that can be made to the basic GPS technique to improve the accuracy of the estimate for the location, and numerous companies like Qualcomm each tout their own flavor. The principal advantage of the GPS techniques is that when it works, the estimate for the location can be accurate to within meters. The GPS techniques are disadvantageous in that they do not work consistently well indoors, in heavily-wooded forests, or in urban canyons.
In accordance with a fourth family of techniques, the location of a wireless terminal is estimated by pattern matching one or more location-dependent traits of one or more electromagnetic signals that are processed (i.e., transmitted and/or received) by the wireless terminal. Common names for this family of techniques include “Wireless Location Signatures,” “RF Pattern Matching,” and “RF Fingerprinting.”
The basic idea is that some traits of an electromagnetic signal remain (more or less) constant as a signal travels from a transmitter to a receiver (e.g., frequency, etc.) and some traits change (e.g., signal strength, relative multi-path component magnitude, propagation delay, etc.). A trait that changes is considered a “location-dependent” trait. Each location can be described or associated with a profile of one or more location-dependent traits of one or more electromagnetic signals. A wireless terminal at an unknown location can observe the traits and then attempt to ascertain its location by comparing the observed traits with a database that correlates locations with expected or predicted traits.
There are numerous tricks that can be made to the basic Wireless Location Signatures technique to improve the accuracy of the estimate for the location, and numerous companies like Polaris Wireless each tout their own flavor. The principal advantage of the Wireless Location Signatures technique is that it is highly accurate and works well indoors, in heavily-wooded forests, and in urban canyons.
All of these techniques rely on empirical data as their basis, and the accuracy of these techniques suffer when some or all of the data is misleading or erroneous. Typically, it is easy to identify and disregard data that is clearly unreasonable. For example, if one datum indicates that a wireless terminal is inside of the Sun, that datum is clearly erroneous and can be disregarded. In some cases a reasonable estimate for the location of the wireless terminal can be generated with the remaining data, and sometimes it cannot.
In contrast, it is difficult to identify data that is apparently reasonable, but misleading or erroneous. For example, if one datum in a set of data suggests a wireless terminal is on a lake near a highway, the datum appears reasonable, but it might or might not be erroneous. For example, the datum might be entirely correct because the wireless terminal is on a boat on the lake. Alternatively, the datum might be erroneous because the wireless terminal is in a car on the highway next to the lake. In either case, it is not easy to know whether using that datum is improving or degrading the overall accuracy of the estimate.
Unfortunately, apparently reasonable, but erroneous or misleading empirical data is commonly used as the basis for estimating the location of a wireless terminal, and, therefore, a technique is needed that ameliorates or eliminates the effect of such data.
SUMMARY OF THE INVENTION
The present invention enables an estimate of the location of a wireless terminal to be generated without some of the costs and disadvantages of techniques for doing so in the prior art. For example, some embodiments of the present invention are adept at discounting the contribution of apparently reasonable but erroneous or misleading data.
For example, the illustrative embodiment of the present invention receives data that is evidence of the location of a wireless terminal at each of a plurality of different times. The illustrative embodiment then generates an initial hypothesis for the location of the wireless terminal at each time assuming that all of the data is correct and equally probative. Next, the illustrative embodiment generates an alternative hypotheses for each initial hypothesis on the assumption that each proper subset of datum is erroneous. This is accomplished by underweighting or discarding each datum in the proper subset.
For example, if the set of data for time t(1) is {A, B, C}, then the initial hypothesis for time t(1) is based on an equal weighting of A, B, and C. Because the set comprises three datum, there are six non-empty subsets of datum: {A}, {B}, {C}, {A, B}, {A, C}, and {B, C}. Each alternative hypothesis for time t(1) can be generated by using the data in each of the non-empty subsets and by underweighting or discarding the data not included in the subset.
These alternative hypothesis can be “snapped” or moved to a nearby road or transportation path, or they can be left alone.
Finally, the illustrative embodiment generates the estimate for the location of the wireless terminal at each time in a time frame by determining which combination of initial hypotheses and alternative hypothesis is the most self-consistent during the entire time frame.
The illustrative embodiment comprises:
receiving, at a location engine, a first signal value whose value is evidence of the location of the wireless terminal at time t(1); receiving, at the location engine, a second signal value whose value is evidence of the location of the wireless terminal at time t(1); receiving, at the location engine, a third signal value whose value is evidence of the location of the wireless terminal at time t(2); generating, at the location engine, a first hypothesis for the location for the wireless terminal at time t(1) based on the first signal value having first weight and the second signal value having second weight, wherein the first weight is greater than the second weight; generating, at the location engine, a second hypothesis for the location for the wireless terminal at time t(1) based on the first signal value having third weight and the second signal value having fourth weight, wherein the third weight is less than the fourth weight; generating, at the location engine, a first hypothesis for the location for the wireless terminal at time t(2) based on the third signal value; and generating, at the location engine, an estimate for the location of the wireless terminal at time t(2) based on:
the first hypothesis for the location for the wireless terminal at time t(1), the second hypothesis for the location for the wireless terminal at time t(1), and the first hypothesis for the location for the wireless terminal at time t(2); and
transmitting, from the location engine, the estimate for the location of the wireless terminal at time t(2) for use by a location-based application; wherein the first weight, the second weight, the third weight, and the fourth weight are all real non-negative numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a diagram of the salient components of wireless telecommunications system 100 in accordance with the prior art.
FIG. 2 depicts a diagram of the salient components of wireless telecommunications system 200 in accordance with the illustrative embodiment of the present invention.
FIG. 3 depicts a block diagram of the salient components of location engine 214 in accordance with the illustrative embodiment.
FIG. 4 depicts a flowchart of the salient processes performed in accordance with the illustrative embodiment of the present invention.
FIG. 5 depicts a road map of geographic region 220 that indicates the four initial hypotheses from Table 2.
FIG. 6 depicts a road map of geographic region 220 that indicates the nine alternative hypotheses generated in task 403 .
FIG. 7 depicts a road map of geographic region 220 that indicates the nine snapped alternative hypotheses generated in task 403 .
FIG. 8 depicts the weighted directed graph that corresponds the initial hypotheses and snapped alternative hypotheses generated in task 406 .
FIG. 9 depicts the minimum weight path through the weighted directed graph depicted in FIG. 8 .
FIG. 10 depicts the road map of geographic region 220 that indicates the final refined hypotheses of the location of wireless terminal at time t, for all t.
DETAILED DESCRIPTION
Overview
FIG. 2 depicts a diagram of the salient components of wireless telecommunications system 200 in accordance with the illustrative embodiment of the present invention. Wireless telecommunications system 200 comprises: wireless terminal 201 , cellular base stations 202 - 1 , 202 - 2 , and 202 - 3 , Wi-Fi base stations 203 - 1 and 203 - 2 , wireless switching center 211 , assistance server 212 , location client 213 , location engine 214 , and GPS constellation 221 , which are interrelated as shown. The illustrative embodiment provides wireless telecommunications service to all of geographic region 220 , in well-known fashion, hypothesizes the location of wireless terminal 201 within geographic region 220 at different times, and uses those hypotheses in a location-based application.
In accordance with the illustrative embodiment, wireless telecommunications service is provided to wireless terminal 201 in accordance with the air-interface standard of the 3 rd Generation Partnership Project (“3GPP”). After reading this disclosure, however, it will be clear to those skilled in the art how to make and use alternative embodiments of the present invention that operate in accordance with one or more other air-interface standards (e.g., Global System Mobile “GSM,” UMTS, CDMA-2000, IS-136 TDMA, IS-95 CDMA, 3G Wideband CDMA, IEEE 802.11 Wi-Fi, 802.16 WiMax, Bluetooth, etc.) in one or more frequency bands. As will be clear to those skilled in the art, a wireless terminal is also known as a “cell phone,” “mobile station,” “car phone,” “PDA,” and the like.
Wireless terminal 201 comprises the hardware and software necessary to be 3GPP-compliant and to perform the processes described below and in the accompanying figures. For example and without limitation, wireless terminal 201 is capable of:
a. measuring one or more location-dependent traits of each of one of more electromagnetic signals (transmitted by cellular base stations 202 - 1 , 202 - 2 , and 202 - 3 and Wi-Fi base stations 203 - 1 and 203 - 2 ) and of reporting the measurements to location engine 214 , and b. transmitting one or more signals and of reporting the transmission parameters of those signals to location engine 214 , and c. receiving GPS assistance data from assistance server 212 to assist wireless terminal 201 in acquiring and processing GPS ranging signals.
Wireless terminal 201 is mobile and can be at any location within geographic region 220 at any time. Although wireless telecommunications system 200 comprises only one wireless terminal, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention that comprise any number of wireless terminals.
Cellular base stations 202 - 1 , 202 - 2 , and 202 - 3 communicate with wireless switching center 211 via wireline and with wireless terminal 201 via radio in well-known fashion. As is well known to those skilled in the art, base stations are also commonly referred to by a variety of alternative names such as access points, nodes, network interfaces, etc. Although the illustrative embodiment comprises three base stations, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention that comprise any number of base stations.
In accordance with the illustrative embodiment of the present invention, cellular base stations 202 - 1 , 202 - 2 , and 202 - 3 are terrestrial, immobile, and within geographic region 220 . It will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which some or all of the base stations are airborne, marine-based, or space-based, regardless of whether or not they are moving relative to the Earth's surface, and regardless of whether or not they are within geographic region 220 .
Cellular base stations 202 - 1 , 202 - 2 , and 202 - 3 comprise the hardware and software necessary to be 3GPP-compliant and to perform the processes described below and in the accompanying figures. For example and without limitation, cellular base stations 202 - 1 , 202 - 2 , and 202 - 3 are capable of:
a. measuring one or more location-dependent traits of each of one of more electromagnetic signals (transmitted by wireless terminal 201 ) and of reporting the measurements to location engine 214 , and b. transmitting one or more signals and of reporting the transmission parameters of those signals to location engine 214 .
Wi-Fi base stations 203 - 1 and 203 - 2 communicate with wireless terminal 201 via radio in well-known fashion. Wi-Fi base stations 203 - 1 and 203 - 2 have a shorter range than cellular base stations 202 - 1 , 202 - 2 , and 202 - 3 , but have a higher bandwidth. The location of Wi-Fi base stations 203 - 1 and 203 - 2 is only known to within approximately 30 meters by detecting their signals through drive testing. Wi-Fi base stations 203 - 1 and 203 - 2 are terrestrial, immobile, and within geographic region 220 .
Wi-Fi base stations 203 - 1 and 203 - 2 are capable of:
c. measuring one or more location-dependent traits of each of one of more electromagnetic signals (transmitted by wireless terminal 201 ) and of reporting the measurements to location engine 214 , and d. transmitting one or more signals and of reporting the transmission parameters of those signals to location engine 214 .
Wireless switching center 211 comprises a switch that orchestrates the provisioning of telecommunications service to wireless terminal 201 and the flow of information to and from location engine 214 , as described below and in the accompanying figures. As is well known to those skilled in the art, wireless switching centers are also commonly referred to by other names such as mobile switching centers, mobile telephone switching offices, routers, etc.
Although the illustrative embodiment comprises one wireless switching center, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention that comprise any number of wireless switching centers. For example, when a wireless terminal can interact with two or more wireless switching centers, the wireless switching centers can exchange and share information that is useful in estimating the location of the wireless terminal. For example, the wireless switching centers can use the IS-41 protocol messages HandoffMeasurementRequest and HandoffMeasurementRequest2 to elicit signal-strength measurements from one another. The use of two or more wireless switching centers is particularly common when the geographic area serviced by the wireless switching center is small (e.g., local area networks, etc.) or when multiple wireless switching centers serve a common area.
In accordance with the illustrative embodiment, all of the base stations servicing wireless terminal 201 are associated with wireless switching center 211 . It will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which any number of base stations are associated with any number of wireless switching centers.
Assistance server 212 comprises hardware and software that is capable of performing the processes described below and in the accompanying figures. In general, assistance server 212 generates GPS assistance data for wireless terminal 201 to aid wireless terminal 201 in acquiring and processing GPS ranging signals from GPS constellation 221 . In accordance with the illustrative embodiment, assistance server 212 is a separate physical entity from location engine 214 ; however, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which assistance server 212 and location engine 214 share hardware, software, or both.
Location client 213 comprises hardware and software that uses the hypothesis for the location of wireless terminal 201 —provided by location engine 214 —in a location-based application, as described below and in the accompanying figures.
Location engine 214 comprises hardware and software that generates one or more hypotheses of the location of wireless terminal 201 as described below and in the accompanying figures. It will be clear to those skilled in the art, after reading this disclosure, how to make and use location engine 214 . Furthermore, although location engine 214 is depicted in FIG. 2 as physically distinct from wireless switching center 211 , it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which location engine 214 is wholly or partially integrated with wireless switching center 211 .
In accordance with the illustrative embodiment, location engine 214 communicates with wireless switching center 211 , assistance server 212 , and location client 213 via a local area network; however it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which location engine 214 communicates with one or more of these entities via a different network such as, for example, the Internet, the Public Switched Telephone Network (PSTN), a wide area network, etc.
In accordance with the illustrative embodiment, wireless switching center 211 , assistance server 212 , location client 213 , and location engine 214 are physically located within geographic region 220 . It will be clear to those skilled in the art, however, after reading this disclosure, how to make and use alternative embodiments of the present invention in which some or all of wireless switching center 211 , assistance server 212 , location client 213 , and location engine 214 are physically located outside of geographic region 220 .
Location Engine 214
FIG. 3 depicts a block diagram of the salient components of location engine 214 in accordance with the illustrative embodiment. Location engine 214 comprises: processor 301 , memory 302 , and local-area network transmitter/receiver 303 , which are interconnected as shown.
Processor 301 is a general-purpose processor that is capable of executing operating system 311 and application software 312 , and of populating, amending, using, and managing Location-Trait Database 313 , as described in detail below and in the accompanying figures. For the purposes of this specification, a “processor” is defined as one or more computational elements, whether co-located or not and whether networked together or not.
For the purposes of this specification, the “Location-Trait Database” is defined as a database that associates one or more location-dependent traits of electromagnetic signals processed (i.e., transmitted and/or received) by wireless terminal 201 with each of a plurality of locations. In general, the Location-Trait Database is what enables location engine 214 to convert observed location-dependent traits into an estimate for the location of wireless terminal 201 . It will be clear to those skilled in the art how to make and use processor 301 .
Memory 302 is a non-volatile memory that stores:
a. operating system 311 , and b. application software 312 , and c. Location-Trait Database 313 .
It will be clear to those skilled in the art how to make and use memory 302 .
Transmitter/receiver 303 enables location engine 214 to transmit and receive information to and from wireless switching center 211 , assistance server 212 , and location client 213 . In addition, transmitter/receiver 303 enables location engine 214 to transmit information to and receive information from wireless terminal 201 and cellular base stations 202 - 1 through 202 - 3 via wireless switching center 211 . It will be clear to those skilled in the art how to make and use transmitter/receiver 303 .
Operation of the Illustrative Embodiment
FIG. 4 depicts a flowchart of the salient processes performed in accordance with the illustrative embodiment of the present invention.
At task 401 , location engine 214 receives signals from wireless switching center 211 whose values are evidence of the location of wireless terminal 201 at different times. Each signal radiates from a different source (e.g., cellular base stations 202 - 1 , 202 - 2 , and 202 - 3 , Wi-Fi base stations 203 - 1 and 203 - 2 , wireless terminal 201 , etc.). Table 1 depicts three signals, S(1), S(2), and S(3), and the values of those signals at times t(1), t(2), t(3), and t(4).
TABLE 1 Nine signals whose values are evidence of the location of wireless terminal 201 in geographic region 220 at four different times. time Signal S(1) Signal S(2) Signal S(3) t(1) SV(1, 1) SV(1, 2) Not Available t(2) SV(2, 1) SV(2, 2) SV(2, 3) t(3) SV(3, 1) Not Available SV(3, 3) t(4) Not Available SV(4, 2) SV(4, 3)
In the signal value SV(t, j), t represents the time for which the signal is evidence, and j represents the source of the signal.
In accordance with the illustrative embodiment, the value of each signal is a signal-strength measurement made by wireless terminal 201 of a radio signal transmitted by one of cellular base stations 202 - 1 and 202 - 2 and Wi-Fi base station 203 - 1 . It will be clear to those skilled in the art, however, after reading this disclosure, how to make and use alternative embodiments of the present invention in which the value of each received signal is a measurement of any location-dependent trait of an electromagnetic signal that is evidence of the location of wireless terminal 201 . For example and without limitation, each signal can be:
i. evidence of the propagation delay—in either one-direction or round-trip-between wireless terminal 120 and another entity (e.g., a cellular base station, a GPS satellite, a Wi-Fi base station, etc.), or ii evidence of the time difference of arrival of a signal transmitted by wireless terminal 201 and two other entities (e.g., a cellular base station, a GPS satellite, a Wi-Fi base station, etc.), or iii. evidence of the angle of arrival of a signal transiting between wireless terminal 201 and another entity (e.g., a cellular base station, a GPS satellite, a Wi-Fi base station, etc.), or iv. evidence that wireless terminal 201 can receive and decode a signal from another entity (e.g., a cellular base station, a GPS satellite, a Wi-Fi base station, etc.), or v. evidence that an entity (e.g., a cellular base station, a GPS satellite, a Wi-Fi base station, etc.) can receive and decode a signal from wireless terminal 201 , or vi. evidence of any location-dependent trait (e.g., signal strength, rake receiver coefficients, phase delay, etc.) of an electromagnetic signal that is processed by wireless terminal 201 , or vii. any combination of i, ii, iii, iv, v, or vi.
In accordance with the illustrative embodiment, three signals are received for time t(2) but only two signals are received for times t(1), t(3), and t(4) because signal value SV(1, 3), SV(3, 2) and SV(4, 1) were not measured or reported. It will be clear to those skilled in the art, however, after reading this disclosure, how to make and use alternative embodiments of the present invention in which any number of signals are received and used for each moment of time.
In accordance with the illustrative embodiment, all of the signals are evidence of the same type of physical quantity (i.e., received signal strength), but it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which the type of physical quantity represented varies (e.g., three signal-strength measurements are received for one moment, one signal-strength measurement and two time-difference of arrival measurements are received for the next moment, etc.). In accordance with the illustrative embodiment, there is signal data available for four moments of time, but it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which data is available for any number of moments.
At task 402 , location engine 214 generates an “initial” hypothesis for the location of wireless terminal 201 at each of times t(1), t(2), t(3), and t(4). Each hypothesis and each estimate of the location of wireless terminal 201 is a latitude-longitude pair.
Each initial hypothesis for the location of wireless terminal 201 is a hypothesis that does not discount the probative value of any signal value. In other words, all of the signals that are evidence of the location of wireless terminal 201 at one time are accorded equal probity for the purposes of creating the initial hypotheses. In practice, this is achieved by weighting each signal value SV(t, j) with weight W(t, j, 0), wherein W(t, j, 0) are equal and non-negative real values for all t and all j.
In accordance with the illustrative embodiment, location engine 215 generates the initial hypotheses using the signals received at task 401 and the technique of wireless location signatures. The wireless location signatures technique is well-known to those skilled in the art and is taught, for example, in U.S. Pat. No. 7,257,414 B2, which is incorporated by reference. It will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which the initial hypotheses are generated using:
i. wireless location signatures, or ii. triangulation, or iii. trilateration, or iv. cellular-base-station cell identification, or v. Wi-Fi-base-station cell identification, or vi. any combination of i, ii, iii, iv, and v.
At time t(2), the initial hypothesis is based on three signals, but at times t(1), t(3), and t(4) the initial hypotheses are based on only two signals. Table 2 depicts the values of each of the four initial hypotheses.
TABLE 2
The initial locations of wireless terminal 201 in
geographic region 220 at four different times.
time
Initial Hypothesis
t(1)
IH(1)
t(2)
IH(2)
t(3)
IH(3)
t(4)
IH(4)
FIG. 5 depicts a road map of geographic region 220 that indicates the four initial hypotheses from Table 2. In the map the initial hypothesis for the location of wireless terminal 201 at time t(i) is depicted by a bull's-eye with the identifier IH(i).
Therefore, the initial hypothesis IH(1) for wireless terminal 201 at time t(1) is on West Street, just south of Left Street. The initial hypothesis IH(2) at time t(2) is between Top Street and North Street, just east of West Street. The ambiguity of whether wireless terminal 201 was on Top Street or North Street at time t(2) is undesirable because a known drug-dealer operates on Top Street and it would be advantageous to know whether the operator of wireless terminal 201 might be involved with the drug dealer or not. The illustrative embodiment of the present invention resolves that ambiguity beginning in task 403 below. The initial hypothesis IH(3) for wireless terminal 201 at time t(3) is between Lakeside Road, North Street, and East Street. The initial hypothesis IH(4) at time t(4) is unambiguously on Lakeside Road.
In accordance with the illustrative embodiment, the initial hypotheses are used as is, but it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which one or more of the initial hypotheses are “snapped” or repositioned to one or more roadways or other transportation paths in the vicinity of the initial hypothesis.
Referring again to FIG. 4 , at task 403 location engine 214 generates additional “alternative” hypotheses for the location of wireless terminal 201 at each time for which two or more signal values are available. Each alternative hypothesis is also a hypothesis for the location of wireless terminal 201 .
In accordance with the illustrative embodiment, location engine 214 uses the same location technique to generate the alternative hypotheses as it did to generate the initial hypotheses in task 402 . It will be clear to those skilled in the art, however, after reading this disclosure, how to make and use alternative embodiments of the present invention in which the candidates hypotheses are generated using an alternative method, such as:
i. wireless location signatures, or ii. triangulation, or iii. trilateration, or iv. cellular-base-station cell identification, or v. Wi-Fi-base-station cell identification, or vi. any combination of i, ii, iii, iv, and v.
In accordance with the illustrative embodiment, each alternative hypothesis for a given time is generated by discounting as unreliable exactly one signal value. For example, when there are N>1 signal values available for a given time, there are N alternative hypotheses generated for that time. When there is only one signal available for a given time, no alternative hypotheses are generated because the one signal value cannot be discounted with respect to itself.
It will be clear to those skilled in the art, however, how to make and use alternative embodiments of the present invention in which there are a different number of alternative hypotheses generated for a given time (e.g., 1, 2, 3, N−1, 2 N −2, N!, etc.). For example, it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which each alternative hypothesis for a given time is generated by discounting as unreliable every combination of signal values. This would generate 2 N −2 alternative hypotheses. Furthermore, some alternative embodiments of the present invention could discount each signal value by a continuous value, which would generate up to N! alternative hypotheses.
In practice, the illustrative embodiment generates each alternative hypothesis AH(t, k) for the location of wireless terminal 201 at time t by weighting each signal value SV(t, j) with weight W(t, j, k), wherein W(t, j, k) is a non-negative real value for all times i, all signals j, and all hypotheses k. It will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which some or all of the discounted signal's values have a weight of zero (0).
Table 3 depicts signals SV(1, 1) and SV(1, 2) and their associated weights for the purposes of generating alternative hypotheses AH(1, 1) and AH(1, 2).
TABLE 3
The weights and their relationships for generating
the alternative hypotheses at time t(1).
Alternative
Signal
Signal
Signal
Weight
Hypothesis
SV(1, 1)
SV(1, 2)
SV(1, 3)
Relationship
AH(1, 1)
W(1, 1, 1)
W(1, 2, 1)
Not
W(1, 1, 1) < W(1, 2, 1)
Available
AH(1, 2)
W(1, 1, 2)
W(1, 2, 2)
Not
W(1, 1, 2) > W(1, 2, 2)
Available
Not
Not
Not
Not
Not
Applicable
Applicable
Applicable
Available
Applicable
Table 4 depicts signals SV(2, 1), SV(2, 2), and SV(2, 3) and their associated weights for the purposes of generating alternative hypotheses AH(2, 1), AH(2, 2), and AH(2, 3).
TABLE 4
The weights and their relationships for
generating the alternative hypotheses at time t(2).
Alternative
Signal
Signal
Signal
Weight
Hypothesis
SV(2, 1)
SV(2, 2)
SV(2, 3)
Relationship
AH(2, 1)
W(2, 1, 1)
W(2, 2, 1)
W(2, 3, 1)
W(2, 1, 1) < W(2, 2, 1)
W(2, 1, 1) < W(2, 3, 1)
W(2, 2, 1) = W(2, 3, 1)
AH(2, 2)
W(2, 1, 2)
W(2, 2, 2)
W(2, 3 ,2)
W(2, 2, 2) < W(2, 1, 2)
W(2, 2, 2) < W(2, 3, 2)
W(2, 1, 2) = W(2, 3, 2)
AH(2, 3)
W(2, 1, 3)
W(2, 2, 3)
W(2, 3, 3)
W(2, 3, 3) < W(2, 1, 3)
W(2, 3, 3) < W(2, 2, 3)
W(2, 1, 3) = W(2, 2, 3)
In Table 4, W(2, 2, 1)=W(2, 3, 1), W(2, 1, 2)=W(2, 3, 2), and W(2, 1, 3)=W(2, 2, 3), but it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which some or all of these relationships are not true in order to partially discount some signal values. For example, W(2, 2, 1)<W(2, 3, 1), W(2, 1, 2)<W(2, 3, 2), W(2, 1, 3)<W(2, 2, 3), W(2, 2, 1)>W(2, 3, 1), W(2, 1, 2)>W(2, 3, 2), and W(2, 1, 3)>W(2, 2, 3).
Table 5 depicts signals SV(3, 1) and SV(3, 3) and their associated weights for the purposes of generating alternative hypotheses AH(3, 1) and AH(3, 3).
TABLE 5
The weights and their relationships for generating
the alternative hypotheses at time t(3).
Alternative
Signal
Signal
Signal
Weight
Hypothesis
SV(3, 1)
SV(3, 2)
SV(3, 3)
Relationship
AH(3, 1)
W(3, 1, 1)
Not
W(3, 3, 1)
W(3, 1, 1) < W(3, 3, 1)
Available
Not
Not
Not
Not
Not
Applicable
Applicable
Available
Applicable
Applicable
AH(3, 3)
W(3, 1, 3)
Not
W(3, 3, 3)
W(3, 1, 3) > W(3, 3, 3)
Available
Table 6 depicts signal values SV(4, 2), and SV(4, 3) and their associated weights for the purposes of generating alternative hypotheses AH(4, 2), and AH(4, 3).
TABLE 6
The weights and their relationships for generating
the alternative hypotheses at time t(4).
Alternative
Signal
Signal
Signal
Weight
Hypothesis
SV(4, 1)
SV(4, 2)
SV(4, 3)
Relationship
Not
Not
Not
Not
Not
Applicable
Available
Applicable
Applicable
Applicable
AH(4, 2)
Not
W(4, 2, 2)
W(4, 3, 2)
W(4, 2, 2) < W(4, 3, 2)
Available
AH(4, 3)
Not
W(4, 2, 3)
W(4, 3, 3)
W(4, 2, 3) > W(4, 3, 3)
Available
FIG. 6 depicts a road map of geographic region 220 that indicates the four initial hypotheses generated in task 402 plus the nine alternative hypotheses generated in task 403 . In the map the alternative hypotheses of the location of wireless terminal 201 are represented by a bull's-eye with the identifier AH(t, k).
In general, the alternative hypotheses for time t(t) are in the general vicinity of the initial hypotheses for the same time, as generally would be expected. But the generation and mapping of the alternative hypotheses does not, per se, resolve the ambiguities presented by the initial hypotheses. For example, the alternative hypothesis AH(1,2) on Left Street and the alternative hypothesis AH(1, 1) on West Street do not unambiguously resolve the question presented by the initial hypothesis IH(1) of whether wireless terminal 201 was on West Street or Left Street at time t(1). Ambiguities like these are resolved beginning in task 404 below.
At task 404 , location engine 214 generates a snapped alternative hypothesis SAH(t, k) for each alternative hypothesis AH(t, k). The snapped alternative hypothesis SAH(t, k) is also a hypothesis for the location of wireless terminal 201 .
In accordance with the illustrative embodiment, the snapped alternative hypothesis SAH(t, k) is a location on a road that is the shortest Euclidean distance between the alternative hypothesis AH(t, k) and any point on any road. The snapped alternative hypothesis SAH(t, k) corresponding to each alternative hypothesis AH(t, k) is depicted in Table 7 and FIG. 7 .
TABLE 7
The alternative hypotheses and their
corresponding snapped alternative hypotheses.
Snapped
Alternative
Alternative
Hypothesis
Hypothesis
AH(1, 1)
SAH(1, 1)
AH(1, 2)
SAH(1, 2)
AH(2, 1)
SAH(2, 1)
AH(2, 2)
SAH(2, 2)
AH(2, 3)
SAH(2, 3)
AH(3, 1)
SAH(3, 1)
AH(3, 3)
SAH(3, 3)
AH(4, 2)
SAH(4, 2)
AH(4, 3)
SAH(4, 3)
In accordance with the illustrative embodiment, there is one snapped alternative hypothesis for each alternative hypothesis, but it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which some or all of the alternative hypothesis have a plurality of snapped alternative hypotheses.
Referring again to FIG. 4 , at task 405 , location engine 214 generates a measure of distance between each snapped alternative hypothesis SAH(t, k) and the corresponding initial hypothesis B(t) to generate a measure of discrepancy MOD(t, k). In accordance with the illustrative embodiment, the measure of distance is the Euclidean distance. The measures of discrepancy are depicted in Table 8.
TABLE 8
The alternative hypotheses and their
associated measures of discrepancy.
Snapped
Corresponding
Alternative
Initial
Measure of
Hypothesis
Hypothesis
Discrepancy
SAH(1, 1)
B(1)
MOD(1, 1)
SAH(1, 2)
B(1)
MOD(1, 2)
SAH(2, 1)
B(2)
MOD(2, 1)
SAH(2, 2)
B(2)
MOD(2, 2)
SAH(2, 3)
B(2)
MOD(2, 3)
SAH(3, 1)
B(3)
MOD(3, 1)
SAH(3, 3)
B(3)
MOD(3, 3)
SAH(4, 2)
B(4)
MOD(4, 2)
SAH(4, 3)
B(4)
MOD(4, 3)
At task 406 , location server 214 generates a weighted directed graph that comprises:
(i) a node that corresponds to each initial hypothesis B(t), for all t, and (ii) a node that corresponds to each snapped alternative hypothesis SAH(t, k), for all t and all k, and (iii) a directed link from each initial hypothesis B(t) to initial hypothesis B(t+1), for all t, and (iv) a directed link from each initial hypothesis B(t) to each snapped alternative hypothesis SAH(t+1, k), for all t and all k, and (v) a directed link from each snapped alternative hypothesis SAH(t, k) to each initial hypothesis B(t+1), for all t and all k, and (vi) a directed link from each snapped alternative hypothesis SAH(t, k) to each snapped alternative hypothesis SAH(t+1, k), for all t and all k.
The result is a directed graph, as shown in FIG. 8 , that represents every possible combination of paths from time t(1) to time t(4). All of the nodes that correspond to the same time t are depicted in a single column, and the nodes corresponding to time t are depicted in a column to the left of the nodes corresponding to time t+1.
In accordance with the illustrative embodiment,
(i) each node that corresponds to a initial hypothesis B(t) has an associated cost of zero (0), and (ii) each node that corresponds to a snapped alternative hypothesis SAH(t, k) has an associated cost equal to its associated measure of discrepancy MOD(t, k), and (iii) each directed link from node X to node Y has a cost equal to a measure of the distance between the location associated with node X and the location associated with node Y.
In accordance with the illustrative embodiment, the measure of distance from node X to node Y is the road travel time, but it will be clear to those skilled in the art, after reading this disclosure, how to make and use alternative embodiments of the present invention in which the measure of distance is another metric, such as for example and without limitation, the Euclidean distance from node X to node Y, the road travel time, etc.
At task 407 , location server 214 generates an estimate E(t) for the location of wireless terminal 201 for all t. To accomplish this, location server 214 determines the minimum-cost path through the graph constructed in task 406 using well-known dynamic programming techniques.
Once the minimum-cost path has been determined, the nodes in the minimum-cost path constitute the final, best estimates of the location of wireless terminal 201 at each time.
The minimum-cost path through the directed graph is depicted in FIG. 9 as beginning at snapped alternative hypothesis SAH(1, 1), proceeding to snapped alternative hypothesis SAH(2, 3), proceeding to snapped alternative hypothesis SAH(3, 3), and terminating at initial hypothesis IH(4). Therefore, E(1) is the location corresponding to snapped alternative hypothesis SAH(1, 1), E(2) is the location corresponding to base hypothesis SAH(2, 3), E(3) is the location corresponding to snapped alternative hypothesis SAH(3, 3), and E(4) is the location corresponding to snapped alternative hypothesis IH(4). This is summarized in Table 9.
TABLE 9
The alternative hypotheses and
their corresponding hypotheses.
Estimate
Hypothesis
E(1)
SAH(1, 1)
E(2)
SAH(2, 2)
E(3)
SAH(3, 3)
E(4)
IH(4)
FIG. 10 depicts the road map of geographic region 220 that indicates the final refined hypotheses of the location of wireless terminal at time t, for all t. As part of task 407 , each of the refined hypotheses is transmitted from location engine 214 to location client 213 for use in a location-based application.
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A location engine is disclosed that estimates the location of a wireless terminal using (i) cell ID, (ii) triangulation, (iii) GPS, (iv) RF pattern-matching, or (v) any combination of them. The location engine is adept at discounting the contribution of apparently reasonable but erroneous data. The location engine receives data that are evidence of the location of a wireless terminal at each of a plurality of different times. The location engine then generates an initial hypothesis for the location of the wireless terminal at each time assuming that all of the data is correct and equally probative. Next, the location engine generates one alternative hypothesis for each initial hypothesis and each datum assuming that the datum is erroneous. Finally, the location engine generates the estimate for the location of the wireless terminal at each time by determining which combination of initial hypotheses and alternative hypothesis is the most self-consistent.
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This is a division of application Ser. No. 490,909, filed on Mar. 8, 1990.
FIELD OF THE INVENTION
This invention broadly relates to the field of surface treated inorganic compounds. More particularly, the invention relates to the provision of compositions suitable for use as a papermaking filler material wherein an inorganic base filler material is surface treated with a substance which enhances the performance of the filler in the papermaking process. The invention also relates to a method for improving the papermaking process, especially by reducing the requirement for sizing material and for improving the characteristics of paper produced according to the process.
BACKGROUND OF THE INVENTION
Adequate internal sizing of alkaline papers is an important issue for most papermakers. Early development of cellulose reactive sizing agents resulted in poor control of sizing with excessive amounts of sizing agent used, resulting in increased wet-end deposits, press picking, and in coefficient of friction problems with the paper surface. Problems still occur, mainly due to the overuse of sizing materials. The problems are caused by high surface area materials (e.g., filler and fines) found in the wet-end, which adsorb the size and render it ineffective.
The purpose of internal sizing is to impart resistance to liquid penetration to the sheet. Internal sizing, along with sheet porosity (which is controlled at the size press), controls ink penetration in printing and writing papers, along with binder migration in coating basestock. The sizing of alkaline papers with cellulose reactive sizing agents or "synthetic sizes" has been established for more than 30 years. Two synthetic sizes presently in commercial use, alkyl ketene dimer (AKD) and alkenyl succinic anhydride (ASA), impart sizing to the sheet by means of a chemical reaction (covalent bonding) with the hydroxyl groups of cellulose fiber.
All commonly used untreated fillers (e.g., clay, titanium dioxide, calcium carbonate) are known to have a detrimental effect on sizing. Studies of alkaline papers filled with various types of calcium carbonate have revealed strong inverse correlations between filler specific surface area and internal sizing values in the sheet measured by the Hercules size test (HST). In circumstances where increasing the filler content would be advantageous, associated sizing problems have occurred affecting sheet quality, machine performance, and runnability.
SUMMARY OF THE INVENTION
Specially modified precipitated calcium carbonate (PCC) fillers, which can be synthesized at an on-site PCC plant, have been developed to make the sizing of filled sheets more economical and efficient. Laboratory results have shown that by using a chemically modified PCC filler, which has been surface treated with a cationic polymer, the amount of sizing agent can be reduced by one-half while improving other properties as well.
It has been discovered that the addition of certain cationic resin materials to papermaking filler materials such as calcium carbonate, either ground natural calcium carbonate from limestone, or precipitated, greatly enhances the performance of the filler material and results, in a paper requiring the addition of substantially less wet end sizing agent, and having excellent opacity and tensile strength properties.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of Hercules size measurement versus filler content for handsheets containing modified and unmodified fillers.
FIG. 2 is a plot of water pick-up as measured by the Cobb size test versus filler content for handsheets containing modified and unmodified fillers.
FIG. 3 is a plot of Hercules size measurement versus filler content for handsheets containing modified filler at various levels of polymer treatment.
FIG. 4 is a plot of Hercules size measurement versus filler content for handsheets containing modified and unmodified fillers at different sizing levels.
FIG. 5 is a plot of sheet opacity versus filler content for handsheets containing modified and unmodified fillers.
FIG. 6 is a plot of sheet opacity versus sheet tensile strength for handsheets containing modified and unmodified fillers.
FIG. 7 is a plot of sheet brightness versus filler content for handsheets containing modified and unmodified fillers.
FIG. 8 is a plot of Hercules size measurement versus filler content for sheets containing modified and unmodified fillers made on a pilot papermachine.
FIG. 9 is a plot of water pick-up as measured by the Cobb size test versus filler content for sheets containing modified and unmodified fillers made on a pilot papermachine.
FIG. 10 is a plot of corrected sheet opacity versus filler content for sheets containing modified and ummodified fillers made on a pilot papermachine.
FIG. 11 shows comparative microscopic photographs illustrating distribution of filler material for sheets containing modified and unmodified fillers made on a pilot papermachine.
DETAILED DESCRIPTION OF THE INVENTION
The cationic polymers found to be most effective for surface treating the papermaking filler materials are dimers of the general formula: ##STR1## where R is a hydrocarbon group selected from the group consisting of alkyl with at least 8 carbon atoms, cycloalkyl with at least 6 carbon atoms, aryl, aralkyl and alkaryl. Specific dimers are octyl-, decyl-, dodecyl-, tetradecyl-, hexadecyl-, octadecyl-, eikosyl-, dokosyl-, tetrakosyl-, phenyl-, benzyl-beta-naphthyl-, and cyclohexyl- dimer. Other utilizable dimers are dimers produced from mining acids, naphthenic acid, delta-9,10-decylenic acid, delta-9,10 dodecylenic acid, palmitoline acid, olein acid, ricine olein acid, linoleate, linoleic acid, and olestearic acid, as well as dimers manufactured from natural fatty acid mixtures, such as are obtained from cocoanut oil, babassu oil, palm seed oil, palm oil, olive oil, peanut oil, rape seed oil, beef suet and lard, and mixtures of the above.
The polymer is made cationic as a result of treating the dimer with a polyamino-amide and/or polyamine polymer reacted with an epoxidized halohydrin compound, such as epichlorohydrin, thereby forming tertiary and quaternary amine groups on the dimer surface. It is preferred that the cationic charge on the dimer be derived primarily from quaternary amine groups. A polymer material of this type is manufactured by and is commercially available from Hercules, Inc., Wilmington, Del., under the tradename Hercon.
It has been discovered that the use of from about 0.1% to about 10.0% by weight of the cationic polymer material on a filler significantly enhances filler performance in terms of a reduction in the requirement for the addition of wet end sizing agent and an improvement in the optical and physical properties, particularly opacity, Z-directional filler distribution and tensile strength, of the resulting paper in which the filler is utilized.
For the case of utilizing clay as a filler material, it has been discovered that surface treatment of the filler with from about 1.0 to about 2.0 weight percent of a cationic polymer material of the aforesaid type is effective in producing a filler clay having a substantially reduced sizing demand.
It has also been discovered that surface treatment of a PCC filler material with from about 0.25 to about 2.0 weight percent of a cationic polymer material of the aforesaid type is effective in producing a filler having a substantially reduced sizing demand.
Other filler materials, such as titanium dioxide, talc and silica/silicate pigments, which if used untreated have a detrimental effect on sizing, are utilizable when treated with a cationic polymer material of the aforesaid type according to the present invention.
For all types of fillers, it has been discovered that the amount of cationic polymer required to be added to the filler material-containing slurry is directly correlated with the surface area of the filler material.
EXAMPLES
The nature and scope of the present invention may be more fully understood in view of the following non-limiting examples, which demonstrate the effectiveness of cationic polymer modified filler materials.
EXAMPLE 1
Preparation and Comparative Testing of Handsheets Containing Modified and Unmodified Fillers
Comparative Formax (Noble and Wood) handsheets (60 g/m 2 or 40 lbs./3300 ft 2 ) were prepared from a furnish consisting of 75% bleached hardwood and 25% bleached softwood Kraft pulps beaten to 400 Canadian Standard Freeness (CSF) at pH 7.0 in distilled water. A high molecular weight, medium charge density, cationic polyacrylamide (PAM) retention aid was used at, 0.05%. Synthetic sizing agents (AKD or ASA) were added at levels from 0.10% to 0.30%. Several fillers were used, including various polymer-modified PCC fillers to test the effect of the polymer treatment against unmodified PCC and fine ground limestone (FGL). The fillers were added to the furnish at 20% solids to achieve 8%, 16%, 24% and 40% filler in the finished sheets. In addition, a blank, containing no filler was prepared and tested. Distilled water was used throughout the handsheet process. The sheets were conditioned at 50% RH and 23° C. and tested for grammage, percent filler, HST, Cobb size, opacity, brightness, caliper, tensile, and porosity. Scattering coefficients were determined using the appropriate reflectance values and Kubelka-Munk equations. Elemental mapping of the filler distribution in the sheet, both in the XY plane and in the Z-directional plane, was performed using a scanning electron microscope (SEM) with elemental analysis capabilities.
Sizing values (HST and Cobb) for sheets filled with the modified PCC fillers were significantly improved, with higher levels of polymer on the PCC providing significantly better sizing at all loading levels greater than 10% versus a low sizing demand filler (e.g., FGL) (FIGS. 1, 2, and 3). Comparable sheets can be made using one-third less sizing agent when a 0.5 percent by weight cationic polymer-treated PCC filler was used (FIG. 4), and as the graph reveals, even less sizing agent was needed using a 1.0 percent by weight cationic polymer-treated PCC filler. Table I also shows the efficiency of polymer treatment of the filler.
A secondary benefit derived from the modified fillers was an increase of one-half point in opacity without a subsequent loss in tensile strength or sheet brightness (FIGS. 5, 6, and 7). The increased opacity without loss of strength or brightness appears to be predominantly due to the substantial increase in the cationic charge of the modified filler particles. Increasing the cationic charge on the particles makes them adsorb more uniformly on the fiber surface and less between fiber crossings. Scanning electron micrographs revealed better distribution of the filler in the sheet for the modified PCC fillers which supports improved optical performance. Table II shows the relationship between the filler's specific surface area and polymer treatment level on sizing values. At higher surface area, more polymer is needed to cover the surface and provide improved sizing. Unexpectedly, as the filler level is increased in the sheet, the sizing values continue to rise for all but the highest surface area filler. This indicates that by the method of treatment of this invention, increased sizing is maintainable through the use of higher filler levels in the sheet. This condition cannot be achieved by the use of untreated fillers.
EXAMPLE 2
Evaluation of Modified PCC Fillers for Retention and Drainage
A vacuum drainage jar apparatus was used to measure the retention and drainage characteristics of the fillers under conditions similar to an actual high-speed papermachine. The furnish was the same as used in Example 1 with the retention aid level evaluated at 0.05%. The fillers were added so that a content of 16%±1.0% would be retained in the final pad. The stock (0.5% consistency) was agitated in a three vane jar at 750 rpm. Automatic control placed the contents of the jar under a vacuum of 10 kPa during initial drainage followed by 5 seconds of high vacuum (50 kPa). The pad which formed was weighed and then dried and reweighed to yield percent sheet dryness values (these numbers predict the ease at which water is removed from the sheet). Percent filler retention was calculated from the amount of calcium carbonate in the fiber pad via X-ray fluorescence and the known amount added to the stock.
Improved papermachine runnability can be measured in many ways. Improved drainage on the wire along with increased sheet dryness off the couch provides the papermaker with the opportunity to increase machine speed (increase production rate) and/or decrease steam consumption at the dryers (increased profitability). Improved filler retention without the need to use excessive amounts of retention aid enhances sheet quality which includes formation. This also leads to better runnability and economics from a cleaner wet end system. Retention and drainage results, shown in Table III, using a vacuum drainage jar revealed improved first pass filler retention for the modified PCC fillers. Sheet dryness values were also improved over the untreated PCC filler, indicating better drainage. The experiments were conducted under precise and well-controlled conditions in the laboratory, however these results are transferable to a papermachine leading to better wet end control with improved runnability, as is shown in Examples 3 and 4, following.
EXAMPLE 3
Comparative Testing of Furnishes Incorporating Both Modified and Unmodified Fillers on Actual Pilot Papermachine
A pilot machine run was conducted utilizing a pilot scale papermachine. A 60 g/m 2 (40 lbs./3300 ft 2 ) sheet was produced using the same furnish composition as in Examples 1 and 2. The same cationic retention aid was utilized at 0.0125% and an AKD sizing agent was added at 0.15%. Various calcium carbonate fillers (i.e., untreated commercial PCC, untreated commercial FGL, 0.5 and 1.0 percent by weight cationic polymer-modified PCC's) were added to achieve levels of 8%, 16%, and 24% filler in the sheet.
The paper was tested for the same properties as in Example 1.
The fillers were characterized with respect to particle size by gravity sedimentation analysis using a Micromeritics Sedigraph 5000D. Specific surface area was determined by the use of BET nitrogen adsorption analysis. Dry brightness was measured using a Hunter LabScan. Particle charge (zeta potential) was determined using doppler laser light scattering technique from a Coulter DELSA 440. Filler properties are listed in Table IV.
Results from the pilot papermachine corroborated the results from the handsheet work. Sizing values shown in FIGS. 8 and 9 reveal the improved sizing performance for the modified PCC fillers. Since the Hercules size test (HST) was not sensitive enough to distinguish between sizing differences at the low end, the Cobb test was used to better ascertain their performance. The Cobb sizing test results show the characteristic increase in water pick-up for the commercial fillers (i.e., FGL and PCC) with increasing filler loading. This increase is virtually eliminated when utilizing the modified PCC fillers. In addition, 1.0 percent by weight cationic polymer-modified PCC filler provides essentially the same resistance to water pick-up at all filler loading levels as the unfilled sheet using the equivalent amount of sizing agent. Print quality evaluated through microscopic analysis of half-tone dots shows a marked improvement in ink hold-out in sheets using the modified PCC fillers.
There was a one-half point improvement in opacity, corroborating laboratory results (FIG. 10). Calcium elemental mapping of the filler distribution in the sheet (FIG. 11) revealed better distribution, especially in the Z-directional plane, for the modified PCC fillers.
EXAMPLE 4
Comparative Testing of Furnishes Incorporating Both Modified and Unmodified Fillers on a Production Papermachine
A mill trial was conducted utilizing a Fourdrinier papermachine running at 2000 fpm. A 60 g/m 2 (40 lbs/3300 ft 2 ) high opacity sheet was run with and without a modified PCC filler as part of the furnish composition. The modified PCC filler was treated with 1.5 percent by weight of cationic polymer. An anionic retention aid was utilized along with an ASA sizing agent. Both additives were held constant throughout the trial. Handbox and white-water tray samples were obtained throughout the trial and analyzed for first pass filler retention and total retention. These results are shown in Table V. Significant improvement in both filler retention and total retention were realized. Z-directional distribution of the modified filler through the sheet was also greatly improved. Better distribution of the filler means less two-sidedness, better dimensional stability and better printability of the paper with less associated whitening and dusting (Table V). Paper samples were tested and revealed a 263% improvement in sizing (i.e. 40 sec. vs. 11 sec.) and equivalent opacity with 4.5% less PCC (i.e. 15.0% vs. 15.7%) and 25% less TiO 2 (0.6% vs 0.8%). A 9% improvement in tensile strength was also realized. These results are shown in Table VI. Loss of sizing, referred to as "fugitive sizing", was evaluated after 5 weeks (35 days). The results are shown in Table VII. The samples showed a minimum loss of sizing compared to typical commercially filled sheets. The surface coefficient of friction of the sheets was also evaluated. The surface coefficient of friction of the sheets is an important measure of the runnability of the paper through high-speed reprographic equipment. The results of this evaluation are shown in Table VIII. The polymer-modified PCC-filled sheets showed a better coefficient of friction of the sheet surface than the unmodified sheets.
TABLE I______________________________________Improvements in Paper Properties by Surface Treatmentof Filler with AKD Resin(16% filler in sheet)% AKD* % AKD* Sheetadded added Opacity Brightness HSTto pulp to filler (%) (%) (seconds)______________________________________0.4% 0 87.7 84.3 1580 0.4% 88.5 85.7 3350.6% 0 87.9 83.9 3610 0.6% 88.9 84.9 434______________________________________
TABLE II______________________________________Effect of Surface Area andPolymer Treatment Level on SizingSpecific Surface Polymer HST (sec)Area of CaCO.sub.3 Treatment (filler in sheet)Fillers (m.sup.2 /g) Level (%) 8% 16% 24%______________________________________5.9 0.0 322 246 38 0.5 354 440 626 1.0 413 542 8077.2 0.0 219 114 6 0.5 287 411 556 1.0 316 484 7798.7 0.0 147 5 1 0.5 234 226 44 1.0 301 473 87110.8 0.0 117 8 1 0.5 214 215 36 1.0 259 430 44222.7 0.0 101 4 1 0.5 184 33 2 1.0 239 140 11______________________________________ Blanks (no filler) = 1876 seconds 0.25% AKD added to furnish
TABLE III______________________________________Drainage/Retention Data on Polymer Treated CaCO.sub.3 16% Filler In Pad Drainage Rate First (cc/sec).sup.a /Sheet Pass Filler Dryness (%).sup.b Retention %______________________________________Unfilled Sheet 112/19.8 --PCC 87/22.2 72.0PCC-modified with 91/22.5 77.40.5% polymerPCC-modified with 94/22.7 76.41.0% polymer______________________________________ .sup.a Confidence Level (C.L.) @ ± cc/sec .sup.b C.L. @ ± 0.2%
TABLE IV__________________________________________________________________________PHYSICAL PROPERTIES OF FILLERS Average Specific Zeta Particle Surface Dry Potential Morphology Size (μm) Area (m.sup.2 /g) Brightness (%) (mV)__________________________________________________________________________Untreated PCC Scalenohedral 1.2-1.4 10-12 99.7 +10.0-+15.00.5 Wt. % Cationic Scalenohedral 1.2-1.4 10-12 98.6 +20.0-+25.0Polymer-modified PCC1.0 Wt. % Cationic Scalenohedral 1.2-1.4 10-12 98.5 +26.0-+31.0Polymer-modified PCCUntreated FGL Ground 2.0 5.9 98.4 -23.1__________________________________________________________________________
TABLE V______________________________________Retention Results from Mill Trial Untreated 1.5 Wt. % Cationic Commercial Polymer-Modified PCC PCC______________________________________Total Retention (%) 78.3 80.7First-Pass Filler 50.0 56.1Retention (%)% Filler (felt side) 22.7 18.6% Filler (wire side) 19.4 17.7______________________________________
TABLE VI______________________________________Physical Properties from Mill Trial Untreated 1.5 Wt. % Cationic Commercial Polymer-Modified PCC PCC______________________________________Basis Weight 39.0 40.1(lb/3300 ft.sup.2)PCC (%) 15.7 15.0TiO.sub.2 (%) 0.8 0.6Total Filler (%) 16.5 15.6Corrected Opacity (%) 88.3 88.2Machine Direction 7.77 8.50Breaking Length (km)Hercules Size 11 40Test (sec.)______________________________________
TABLE VII______________________________________Fugitive Sizing Results from Mill Trial(Reel No. 6 and 10) 1.5 Wt. % Untreated Cationic Commercial Polymer- PCC Modified PCC______________________________________Hercules Size Test (sec) 9 37(initial testing)Hercules Size Test (sec) 7 36(35 days later)Percent Change in Sizing (%) -22 -3______________________________________
TABLE VIII______________________________________Coefficient of Friction (COF) on Surface ofPaper from Mill Trial Untreated 1.5 Wt. % Cationic Commercial Polymer-Modified PCC PCC______________________________________COF* (static) .308 .385COF* (dynamic) .214 .281______________________________________ ##STR2## Contact: feltto-wire side
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Material, such as natural ground and precipitated calcium carbonate, when modified by surface-treatment with a cationic polymer, has been discovered to be highly effective as a filler material in the making of paper. Utilization of this type of filler material greatly improves the papermaking process by reducing the usage of wet end sizing agent, improving opacity, improving filler retention in the furnish, and causing better drainage on the papermachine, all of which result in the production of a high quality paper having excellent opacity and tensile strength characteristics. The nature of the polymer-modified filler material, the process for its preparation and the method of its use in papermaking are disclosed.
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FIELD OF THE INVENTION
[0001] The present invention relates to pyridinecarboxamide derivatives, a preparation method thereof and a pharmaceutical composition containing the same, as well as their use as therapeutic agents, especially as inhibitors of the Renal Outer Medullary Potassium channel (ROMK), and in the preparation of medicaments for the treatment and/or prevention of disorders resulting from excessive salt and water retention, including hypertension and heart failure.
BACKGROUND OF THE INVENTION
[0002] Increasing renal salt reabsorption can cause a risk of hypertension. On the contrary, inhibition of renal reabsorption function can promote the excretion of urine, which results in diuretic and antihypertensive effects. Common diuretics are thiazide diuretics, which are first-line antihypertensive drugs in USA that primarily act on sodium-chloride (Na + —Cl) − transporters. The Loop diuretics are more effective for patients with impaired renal function, and they play a role through sodium-potassium-chloride (Na + —K + -2Cl − )— transfer proteins. However, both drugs can cause hypokalemia (symptoms: weakness, fatigue, muscle cramps, constipation, and heart rhythm problems, such as arrhythmia), which increases the risk of morbidity and mortality of cardiovascular disease.
[0003] Renal Outer Medullary Potassium channel (ROMK) is also known as the inward-rectifying potassium channel 1.1 (Kir1.1). The ROMK channel, cooperating with the Na+-K+-2Cl— co-transfer protein NKCC2 (responsible for NaCl transport) through the apical membrane conductance of the renal thick ascending limb (TAL), can regulate the reabsorption of potassium. The ROMK was found to be directly associated with the renal secretory channel. When the ROMK gene is knocked out in mice, there is a loss of TAL and CCD 35-pS ion channels as well as a loss of the other K+ channels. Batter syndrome is an autosomal recessive disease characterized by massive loss of salt in the kidneys, hypokalemia, and low blood pressure. Batter syndrome is mainly caused by mutations in the ROMK or Na+-K+-2Cl— co-transfer proteins. The difference is that the hypokalemia of the batter syndrome caused by the mutation of ROMK is much milder compared to that caused by the mutation of Na+-K+-2Cl— co-transfer proteins. In summary, inhibition of ROMK function can effectively inhibit the salt reabsorption function of Na+-K+-2Cl— co-transfer proteins and promote the excretion of urine, thereby resulting in diuretic and antihypertensive effects, without causing hypokalemia. Although a number of ROMK inhibitors have been disclosed at present, such as in PCT Patent Application Publications WO2010129379, WO2012058134, WO2012058116, WO2012058134, WO2013066714, WO2013028474, WO2014085210, WO2014018764, WO2014015495, WO2014085210, WO2013039802, WO2013062892 and WO2012058116, more compounds with better hERG selectivity need to be developed. The present invention provides a series of novel compounds represented by general formula (I), wherein a polar group is added, which can reduce ClogP, enhance the hERG selectivity and are much safer, while maintaining the ROMK inhibitory activity.
SUMMARY OF THE INVENTION
[0004] The present invention is directed to a compound of formula (I),
[0000]
[0000] or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof,
wherein
R 1 is alkyl, wherein the alkyl is optionally further substituted by one or more groups selected from the group consisting of halogen, hydroxyl, alkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, carboxyl and carboxylic ester;
R 2 is selected from the group consisting of hydrogen, alkyl, halogen, cyano, nitro, alkoxy, cycloalkyl and heterocyclyl, wherein the alkyl, alkoxy, cycloalkyl or heterocyclyl is optionally further substituted by one or more groups selected from the group consisting of alkyl, halogen, hydroxyl, hydroxyalkyl, alkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, carboxyl and carboxylic ester;
R 3 is selected from the following groups:
[0000]
[0000] R 4 and R 5 are each independently selected from the group consisting of hydrogen, alkyl, halogen, cyano, nitro, alkoxy, cycloalkyl, heterocyclyl, aryl and heteroaryl;
R 6 is selected from hydrogen, alkyl and halogen;
n is 0, 1 or 2.
[0005] In a preferred embodiment of the present invention, a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, wherein R 1 is alkyl, wherein the alkyl is optionally further substituted by one or more groups selected from the group consisting of halogen, hydroxyl and alkoxy; R 1 is preferably C 1-6 alkyl, more preferably selected from the group consisting of methyl, ethyl and propyl.
[0006] In a preferred embodiment of the present invention, a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, wherein R 4 is alkyl, and R 5 is hydrogen.
[0007] In another preferred embodiment of the present invention, a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, which is a compound of formula (II):
[0000]
[0000] or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, wherein R 1 , R 2 , R 4 and n are as defined in formula (I).
[0008] In another preferred embodiment of the present invention, a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, which is a compound of formula (III):
[0000]
[0000] or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, wherein R 1 , R 2 , R 4 and n are as defined in formula (I).
[0009] In another preferred embodiment of the present invention, a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, which is a compound of formula (IV):
[0000]
[0000] or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, wherein R 1 , R 2 , R 3 and n are as defined in formula (I).
[0010] In another preferred embodiment of the present invention, a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, which is a compound of formula (V):
[0000]
[0000] or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, wherein R 1 , R 2 , R 4 and n are as defined in formula (I).
[0011] In another preferred embodiment of the present invention, a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, which is a compound of formula (VI):
[0000]
[0000] or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, wherein R 1 , R 2 , R 4 and n are as defined in formula (I).
[0012] Typical compounds of the present invention include, but are not limited to,
[0000] Example No. Structure and name 1 (R)-5-cyano-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3- dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)-4- methoxypicolinamide 2 (R)-5-cyano-4-ethoxy-N-(1-(2-hydroxy-2-(4-methyl-1-oxo- 1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl) picolinamide 3 (R)-5-cyano-4-(2-fluoroethoxy)-N-(1-(2-hydroxy-2-(4-methyl- 1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl) picolinamide 4 (R)-5-cyano-4-(difluoromethoxy)-N-(1-(2-hydroxy-2-(4- methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin- 4-yl)picolinamide
or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof.
[0013] The present invention further provides a compound of formula (IA), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, as the intermediate for the preparation of the compound of formula (I):
[0000]
[0000] wherein
R 1 is alkyl, wherein the alkyl is optionally further substituted by one or more groups selected from the group consisting of halogen, hydroxyl, alkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, carboxyl and carboxylic ester;
R 2 is selected from the group consisting of hydrogen, alkyl, halogen, cyano, nitro, alkoxy, cycloalkyl and heterocyclyl, wherein the alkyl, alkoxy, cycloalkyl or heterocyclyl is optionally further substituted by one or more groups selected from the group consisting of alkyl, halogen hydroxyl, hydroxyalkyl, alkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, carboxyl and carboxylic ester;
which can be used as the intermediate in the preparation of the compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof;
n is 0, 1 or 2.
[0014] In another preferred embodiment of the present invention, a compound of formula (IA), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, which is a compound of formula (IVA):
[0000]
[0000] or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof; which can be used as the intermediate in the preparation of the compound of formula (IV), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof; wherein R 1 , R 2 and n are as defined in formula (IA).
[0015] Typical compounds of formula (IA) include, but are not limited to:
[0000] Example No. Structure and name 1e 5-cyano-4-methoxy-N-(piperidin-4-yl)picolinamide
or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof.
[0016] In another aspect, the present invention provides a process for preparing the compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, comprising a step of:
[0000]
[0000] heating a compound of formula (IA) with a substituted benzofuran derivative of formula (IB), preferably with (R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one, to give a compound of formula (I);
wherein R 1 to R 3 and n are as defined in general formula (I).
[0017] Another aspect of this invention is directed to a pharmaceutical composition comprising a therapeutically effective amount of the compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, and pharmaceutically acceptable carriers, diluents or excipients.
[0018] Another aspect of this invention is directed to use of a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or pharmaceutical composition comprising the same, in the preparation of a ROMK inhibitor.
[0019] Another aspect of this invention is directed to use of a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or pharmaceutical composition comprising the same, in the preparation of a medicament for the treatment or prevention of hypertension and/or heart failure.
[0020] Another aspect of this invention is directed to use of a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or pharmaceutical composition comprising the same, in the preparation of a medicament for the treatment or prevention of ROMK mediated diseases, wherein said diseases are preferably selected from the group consisting of hepatic cirrhosis, acute and chronic renal insufficiency, nephrotic syndrome, pulmonary hypertension, cardiovascular disease, myocardial infarction, stroke, cardiac insufficiency, pulmonary hypertonia, atherosclerosis and kidney stones.
[0021] Another aspect of this invention is directed to a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or pharmaceutical composition comprising the same, for use as a ROMK inhibitor.
[0022] Another aspect of this invention is directed to a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or pharmaceutical composition comprising the same, for use in the treatment or prevention of hypertension and/or heart failure.
[0023] Another aspect of this invention is directed to a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or pharmaceutical composition comprising the same, for use in the treatment or prevention of ROMK mediated diseases, wherein said diseases are preferably selected from the group consisting of hepatic cirrhosis, acute and chronic renal insufficiency, nephrotic syndrome, pulmonary hypertension, cardiovascular disease, myocardial infarction, stroke, cardiac insufficiency, pulmonary hypertonia, atherosclerosis and kidney stones.
[0024] Another aspect of this invention is directed to a method for inhibiting ROMK, comprising administering to a patient in need thereof a therapeutically effective amount of a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or the pharmaceutical composition comprising the same.
[0025] Another aspect of this invention is directed to a method for the treatment or prevention of hypertension and/or heart failure, comprising administering to a patient in need thereof a therapeutically effective amount of the compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or a pharmaceutical composition comprising the same.
[0026] Another aspect of this invention is directed to a method for the treatment or prevention of a ROMK-mediated disease or disorder, comprising administering to a patient in need thereof a therapeutically effective amount of a compound of formula (I), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, or a pharmaceutical composition comprising the same, wherein the disease or disorder is preferably selected from the group consisting of hepatic cirrhosis, acute and chronic renal insufficiency, nephrotic syndrome, pulmonary hypertension, cardiovascular disease, myocardial infarction, stroke, cardiac insufficiency, pulmonary hypertonia, atherosclerosis and kidney stones.
[0027] The pharmaceutical compositions containing the active ingredient can be in a form suitable for oral administration, such as a tablet, troche, lozenge, aqueous or oily suspension, dispersible powder or granule, emulsion, hard or soft capsule, or syrup or elixir. Oral compositions can be prepared according to any known method for the preparation of pharmaceutical compositions in the art. Such compositions can contain one or more additives selected from the group consisting of sweeteners, flavoring agents, colorants and preservatives, in order to provide a pleasing and palatable pharmaceutical formulation. A tablet contains the active ingredient and nontoxic pharmaceutically acceptable excipients suitable for the manufacture of the tablet. These excipients can be inert excipients, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, such as microcrystalline cellulose, cross-linked sodium carboxymethyl cellulose, corn starch or alginic acid; binders, such as starch, gelatin, polyvinylpyrrolidone or acacia; and lubricants, such as magnesium stearate, stearic acid or talc. The tablet can be uncoated or coated by means of known techniques, which can mask drug taste or delay the disintegration and absorption of the active ingredient in the gastrointestinal tract, thereby providing sustained release over an extended period. For example, a water soluble taste masking material can be used, such as hydroxypropyl methylcellulose or hydroxypropyl cellulose, or an extended release material can be used, such as ethyl cellulose, or cellulose acetate butyrate.
[0028] Oral formulations can also be provided as hard gelatin capsules in which the active ingredient is mixed with an inert solid diluent, such as calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules in which the active ingredient is mixed with a water soluble carrier, such as polyethylene glycol or an oil medium, for example peanut oil, liquid paraffin, or olive oil.
[0029] Aqueous suspensions contain the active ingredient in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone and gum acacia; dispersants or humectants, which can be a naturally occurring phosphatide, such as lecithin, or a condensation product of an alkylene oxide with fatty acid, such as polyoxyethylene stearate, or a condensation product of ethylene oxide with a long chain aliphatic alcohol, such as heptadecaethyleneoxy cetanol, or condensation products of ethylene oxide with part esters derived from fatty acids and hexitols, such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, such as polyoxyethylene sorbitan monooleate. The aqueous suspensions can also contain one or more preservatives, such as ethylparaben or n-propylparaben, one or more colorants, one or more flavoring agents, and one or more sweeteners, such as sucrose, saccharin or aspartame.
[0030] Oil suspensions can be formulated by suspending the active ingredient in a vegetable oil, such as arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil, such as liquid paraffin. The oil suspension can contain a thickener, such as beeswax, hard paraffin or cetyl alcohol. The aforesaid sweetener and flavoring agent can be added to provide a palatable preparation. These compositions can be preserved by adding an antioxidant, such as butylated hydroxyanisole or α-tocopherol.
[0031] The active ingredient and the dispersant or wetting agent, suspending agent or one or more preservatives can be provided by adding water to prepare dispersible powder and granules suitable for the preparation of an aqueous suspension. Suitable dispersants or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, such as a sweetener, flavoring agent and colorant, can also be added. These compositions can be preserved by adding an antioxidant such as ascorbic acid.
[0032] The present pharmaceutical composition can also be in the form of an oil-in-water emulsion. The oil phase can be a vegetable oil, such as olive oil or arachis oil, or a mineral oil, such as liquid paraffin or a mixture thereof. Suitable emulsifying agents can be naturally occurring phosphatides, such as soy bean lecithin, and esters or partial esters derived from fatty acids and hexitol anhydrides, such as sorbitan monooleate, and condensation products of the aforementioned partial esters with ethylene oxide, such as polyoxyethylene sorbitol monooleate. The emulsion can also contain a sweetener, flavoring agent, preservative and antioxidant. Syrups and elixirs can be formulated with a sweetener, such as glycerol, propylene glycol, sorbitol or sucrose. Such formulations can also contain a demulcent, a preservative, a colorant and an antioxidant.
[0033] The pharmaceutical composition can be in the form of a sterile injectable aqueous solution. The acceptable vehicles and solvents that can be employed are water, Ringer's solution and isotonic sodium chloride solution. The sterile injectable preparation can also be a sterile injectable oil-in-water microemulsion in which the active ingredient is dissolved in the oil phase. For example, the active ingredient can be firstly dissolved in a mixture of soybean oil and lecithin, the oil solution is then introduced into a mixture of water and glycerol and processed to form a microemulsion. The injectable solution or microemulsion can be introduced into an individual's bloodstream by local bolus injection. Alternatively, it may be advantageous to administer the solution or microemulsion in such a way as to maintain a constant circulating concentration of the present compound. In order to maintain such a constant concentration, a continuous intravenous delivery device can be utilized. An example of such device is Deltec CADD-PLUS™ 5400 intravenous injection pump.
[0034] The pharmaceutical composition can be in the form of a sterile injectable aqueous or oily suspension for intramuscular and subcutaneous administration. Such a suspension can be formulated with suitable dispersants or wetting agents and suspending agents as described above according to known techniques. The sterile injectable preparation can also be a sterile injectable solution or suspension prepared in a nontoxic parenterally acceptable diluent or solvent, for example, a solution prepared in 1,3-butanediol. Moreover, sterile fixed oils can easily be used as a solvent or suspending medium. For this purpose, any blending fixed oils including synthetic mono- or di-glyceride can be employed. Moreover, fatty acids, such as oleic acid, can be employed in the preparation of an injectable.
[0035] The present compound can be administered in the form of a suppository for rectal administration. These pharmaceutical compositions can be prepared by mixing drug with a suitable non-irritating excipient that is solid at ordinary temperatures, but liquid in the rectum, thereby melting in the rectum to release the drug. Such materials include cocoa butter, glycerin, gelatin, hydrogenated vegetable oils, mixtures of polyethylene glycols and fatty acid esters of polyethylene glycol with various molecular weights.
[0036] It is well known to those skilled in the art that the dosage of a drug depends on a variety of factors including, but not limited to, the following factors: activity of the specific compound, age, weight, general health, behavior, and diet of the patient, administration time, administration route, excretion rate, drug combination and the like. In addition, the best treatment, such as treatment mode, daily dose of the compound of formula (I) or the type of pharmaceutically acceptable salt thereof can be verified by the traditional therapeutic regimen.
Definitions
[0037] Unless otherwise stated, the terms used herein have the following meanings.
[0038] “Alkyl” refers to a linear or branched saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms, preferably C 1 to C 10 alkyl, more preferably C 1 to C 6 alkyl. Nonlimiting examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, n-hexyl, 1-ethyl-2-methylpropyl, 1,1,2-trimethylpropyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 2,2-dimethylbutyl, 1,3-dimethylbutyl, 2-ethylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,3-dimethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 2,2-dimethylpentyl, 3,3-dimethylpentyl, 2-ethylpentyl, 3-ethylpentyl, n-octyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 2,2-dimethylhexyl, 3,3-dimethylhexyl, 4,4-dimethylhexyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, 2-methyl-2-ethylpentyl, 2-methyl-3-ethylpentyl, n-nonyl, 2-methyl-2-ethylhexyl, 2-methyl-3-ethylhexyl, 2,2-diethylpentyl, n-decyl, 3,3-diethylhexyl, 2,2-diethylhexyl, and the branched isomers thereof. More preferably, an alkyl group is a lower alkyl having 1 to 6 carbon atoms, and nonlimiting examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, n-hexyl, 1-ethyl-2-methylpropyl, 1,1,2-trimethylpropyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 2,2-dimethylbutyl, 1,3-dimethylbutyl, 2-ethylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,3-dimethylbutyl, and the like. The alkyl group can be substituted or unsubstituted. When substituted, the substituent group(s) can be substituted at any available connection point. The substituent group(s) is preferably one or more groups independently selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, thiol, hydroxy, nitro, cyano, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkoxy, heterocyclic alkoxy, cycloalkylthio, heterocyclylthio, oxo, amino, haloalkyl, hydroxyalkyl, carboxyl, carboxylic ester.
[0039] “Cycloalkyl” refers to a saturated and/or partially unsaturated monocyclic or polycyclic hydrocarbon group having 3 to 20 carbon atoms, preferably 3 to 12 carbon atoms, more preferably 3 to 10 carbon atoms, and most preferably 3 to 6 carbon atoms. Nonlimiting examples of monocyclic cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cyclohexadienyl, cycloheptyl, cycloheptatrienyl, cyclooctyl, and the like, preferably cyclopropyl and cyclohexenyl. Polycyclic cycloalkyl includes a cycloalkyl having a spiro ring, fused ring or bridged ring.
[0040] “Spiro cycloalkyl” refers to a 5 to 20-membered polycyclic group with rings connected through one common carbon atom (called a spiro atom), wherein one or more rings can contain one or more double bonds, but none of the rings has a completely conjugated pi-electron system, preferably 6 to 14-membered spiro cycloalkyl, and more preferably 7 to 10-membered spiro cycloalkyl. According to the number of common spiro atoms, spiro cycloalkyl can be divided into mono-spiro cycloalkyl, di-spiro cycloalkyl, or poly-spiro cycloalkyl, and preferably a mono-spiro cycloalkyl or di-spiro cycloalkyl, more preferably 4-membered/4-membered, 4-membered/5-membered, 4-membered/6-membered, 5-membered/5-membered, or 5-membered/6-membered mono-spiro cycloalkyl. Unlimited examples of spiro cycloalkyls include, but are not limited to:
[0000]
[0041] “Fused cycloalkyl” refers to a 5 to 20-membered full-carbon polycyclic group, wherein each ring in the system shares an adjacent pair of carbon atoms with another ring, wherein one or more rings can contain one or more double bonds, but none of the rings has a completely conjugated pi-electron system, preferably 6 to 14 membered fused cycloalkyl, more preferably 7 to 10 membered fused cycloalkyl. According to the number of membered rings, fused cycloalkyl can be divided into bicyclic, tricyclic, tetracyclic or polycyclic fused cycloalkyl, preferably bicyclic or tricyclic fused cycloalkyl, and more preferably 5-membered/5-membered, or 5-membered/6-membered bicyclic fused cycloalkyl. Nonlimiting examples of fused cycloalkyl include, but are not limited to:
[0000]
[0042] “Bridged cycloalkyl” refers to a 5 to 20-membered full-carbon polycyclic group, wherein every two rings in the system share two disconnected atoms, wherein the rings can have one or more double bonds, but none of the rings has a completely conjugated pi-electron system, preferably 6 to 14-membered bridged cycloalkyl, and more preferably 7 to 10-membered bridged cycloalkyl. According to the number of membered rings, bridged cycloalkyl can be divided into bicyclic, tricyclic, tetracyclic or polycyclic bridged cycloalkyl, and preferably bicyclic, tricyclic or tetracyclic bridged cycloalkyl, and more preferably bicyclic or tricyclic bridged cycloalkyl. Nonlimiting examples of bridged cycloalkyls include, but are not limited to:
[0000]
[0043] Said cycloalkyl can be fused to aryl, heteroaryl or heterocyclyl, wherein the ring bound to the parent structure is cycloalkyl. Nonlimiting examples include indanyl, tetrahydronaphthyl, benzocycloheptyl and the like. The cycloalkyl can be optionally substituted or unsubstituted. When substituted, the substituent group(s) is preferably one or more group(s) independently selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, thiol, hydroxy, nitro, cyano, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkoxy, heterocylic alkoxy, cycloalkylthio, heterocyclylthio, oxo, amino, haloalkyl, hydroxyalkyl, carboxyl, and carboxylic ester.
[0044] “Heterocyclyl” refers to a 3 to 20-membered saturated and/or partially unsaturated monocyclic or polycyclic hydrocarbon group having one or more heteroatoms selected from the group consisting of N, O, and S(O) m (wherein m is an integer selected from 0 to 2) as ring atoms, but excluding —O—O—, —O—S— or —S—S— in the ring, and the remaining ring atoms being carbon atoms. Preferably, heterocyclyl has 3 to 12 atoms with 1 to 4 heteroatoms, more preferably 3 to 10 atoms with 1 to 3 heteroatoms, and most preferably 5 to 6 atoms with 1 to 2 heteroatoms. Nonlimiting examples of monocyclic heterocyclyl include, but are not limited to, pyrrolidinyl, piperidyl, piperazinyl, morpholinyl, thiomorpholinyl, homopiperazinyl, pyranyl, tetrahydrofuranyl, and the like. Polycyclic heterocyclyl includes a heterocyclyl having a spiro ring, fused ring or bridged ring.
[0045] “Spiro heterocyclyl” refers to a 5 to 20-membered polycyclic heterocyclyl with rings connected through one common atom (called a spiro atom), wherein said rings have one or more heteroatoms selected from the group consisting of N, O, and S(O) m (wherein m is an integer selected from 0 to 2) as ring atoms and the remaining ring atoms being carbon atoms, wherein one or more rings can contain one or more double bonds, but none of the rings has a completely conjugated pi-electron system; preferably 6 to 14-membered spiro heterocyclyl, and more preferably 7 to 10-membered spiro heterocyclyl. According to the number of common spiro atoms, spiro heterocyclyl can be divided into mono-spiro heterocyclyl, di-spiro heterocyclyl, or poly-spiro heterocyclyl, preferably mono-spiro heterocyclyl or di-spiro heterocyclyl, and more preferably 4-membered/4-membered, 4-membered/5-membered, 4-membered/6-membered, 5-membered/5-membered, or 5-membered/6-membered mono-spiro heterocyclyl. Nonlimiting examples of spiro heterocyclyls include, but are not limited to:
[0000]
[0046] “Fused heterocyclyl” refers to a 5 to 20-membered polycyclic heterocyclyl group, wherein each ring in the system shares an adjacent pair of atoms with another ring, wherein one or more rings can contain one or more double bonds, but none of the rings has a completely conjugated pi-electron system, and wherein said rings have one or more heteroatoms selected from the group consisting of N, O, and S(O) m (wherein m is an integer selected from 0 to 2) as ring atoms, and the remaining ring atoms being carbon atoms; preferably 6 to 14-membered fused heterocyclyl, and more preferably 7 to 10-membered fused heterocyclyl. According to the number of membered rings, fused heterocyclyl can be divided into bicyclic, tricyclic, tetracyclic or polycyclic fused heterocyclyl, preferably bicyclic or tricyclic fused heterocyclyl, and more preferably 5-membered/5-membered, or 5-membered/6-membered bicyclic fused heterocyclyl. Nonlimiting examples of fused heterocyclyl include, but are not limited to:
[0000]
[0047] “Bridged heterocyclyl” refers to a 5 to 14-membered polycyclic heterocyclyl group, wherein every two rings in the system share two disconnected atoms, wherein the rings can have one or more double bonds, but none of the rings has a completely conjugated pi-electron system, and the rings have one or more heteroatoms selected from the group consisting of N, O, and S(O) m (wherein m is an integer selected from 0 to 2) as ring atoms, and the remaining ring atoms being carbon atoms; preferably 6 to 14-membered bridged heterocyclyl, and more preferably 7 to 10-membered bridged heterocyclyl. According to the number of membered rings, bridged heterocyclyl can be divided into bicyclic, tricyclic, tetracyclic or polycyclic bridged heterocyclyl, and preferably bicyclic, tricyclic or tetracyclic bridged heterocyclyl, and more preferably bicyclic or tricyclic bridged heterocyclyl. Nonlimiting examples of bridged heterocyclyls include, but are not limited to:
[0000]
[0048] Said heterocyclyl can be fused to aryl, heteroaryl or cycloalkyl, wherein the ring bound to the parent structure is heterocyclyl. Nonlimiting examples include, but are not limited to:
[0000]
[0000] etc.
[0049] The heterocyclyl can be optionally substituted or unsubstituted. When substituted, the substituent group(s) is preferably one or more group(s) independently selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, thiol, hydroxy, nitro, cyano, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkoxy, heterocylic alkoxy, cycloalkylthio, heterocylylthio, oxo, amino, haloalkyl, hydroxyalkyl, carboxyl, and carboxylic ester.
[0050] “Aryl” refers to a 6 to 14-membered full-carbon monocyclic ring or polycyclic fused ring (i.e. each ring in the system shares an adjacent pair of carbon atoms with another ring in the system) having a completely conjugated pi-electron system; preferably 6 to 10-membered aryl, more preferably phenyl and naphthyl, and most preferably phenyl. The aryl can be fused to heteroaryl, heterocyclyl or cycloalkyl, wherein the ring bound to the parent structure is aryl. Nonlimiting examples include, but are not limited to:
[0000]
[0051] The aryl can be optionally substituted or unsubstituted. When substituted, the substituent group(s) is preferably one or more groups independently selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, thiol, hydroxy, nitro, cyano, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkoxy, heterocylic alkoxy, cycloalkylthio, heterocyclylthio, amino, haloalkyl, hydroxyalkyl, carboxyl, and carboxylic ester.
[0052] “Heteroaryl” refers to a 5 to 14-membered aryl having 1 to 4 heteroatoms selected from the group consisting of O, S and N as ring atoms and the remaining ring atoms being carbon atoms; preferably 5 to 10-membered heteroaryl, more preferably 5- or 6-membered heteroaryl, such as furyl, thienyl, pyridyl, pyrrolyl, N-alkyl pyrrolyl, pyrimidinyl, pyrazinyl, imidazolyl, tetrazolyl and the like. The heteroaryl can be fused to aryl, heterocyclyl or cycloalkyl, wherein the ring bound to the parent structure is heteroaryl. Nonlimiting examples include, but are not limited to:
[0000]
[0053] The heteroaryl can be optionally substituted or unsubstituted. When substituted, the substituent group(s) is preferably one or more groups independently selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, thiol, hydroxy, nitro, cyano, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkoxy, heterocylic alkoxy, cycloalkylthio, heterocyclylthio, amino, haloalkyl, hydroxyalkyl, carboxyl, and carboxylic ester.
[0054] “Alkoxy” refers to an —O-(alkyl) or an —O-(unsubstituted cycloalkyl) group, wherein the alkyl is as defined above. Nonlimiting examples include, but are not limited to, methoxy, ethoxy, propoxy, butoxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and the like. The alkoxy can be optionally substituted or unsubstituted. When substituted, the substituent is preferably one or more groups independently selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, thiol, hydroxy, nitro, cyano, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkoxy, heterocylic alkoxy, cycloalkylthio, heterocyclylthio, amino, haloalkyl, hydroxyalkyl, carboxyl, and carboxylic ester.
[0055] “Haloalkyl” refers to an alkyl substituted with one or more halogens, wherein alkyl is as defined above.
[0056] “Hydroxy” refers to an —OH group.
[0057] “Hydroxyalkyl” refers to an alkyl substituted with hydroxy, wherein alkyl is as defined above.
[0058] “Halogen” refers to fluorine, chlorine, bromine or iodine.
[0059] “Cyano” refers to a —CN group.
[0060] “Carboxyl” refers to a —C(O)OH group.
[0061] “Carboxylic ester” refers to a —C(O)O(alkyl) or (cycloalkyl) group, wherein the alkyl and cycloalkyl are as defined above.
[0062] “Optional” or “optionally” means that the event or circumstance described subsequently can, but need not, occur, and such description includes the situation in which the event or circumstance may or may not occur. For example, “the heterocyclic group optionally substituted with an alkyl” means that an alkyl group can be, but need not be, present, and such description includes the situation of the heterocyclic group being substituted with an alkyl and the heterocyclic group being not substituted with an alkyl.
[0063] “Substituted” refers to one or more hydrogen atoms in a group, preferably up to 5, more preferably 1 to 3 hydrogen atoms, independently substituted with a corresponding number of substituents. It goes without saying that the substituents only exist in their possible chemical position. The person skilled in the art is able to determine whether the substitution is possible or impossible by experiments or theory without paying excessive efforts. For example, when amino or hydroxy having a free hydrogen is bound to a carbon atom having unsaturated bonds (such as olefinic), it may be unstable.
[0064] A “pharmaceutical composition” refers to a mixture of one or more of the compounds according to the present invention or physiologically/pharmaceutically acceptable salts or prodrugs thereof and other chemical components such as physiologically/pharmaceutically acceptable carriers and excipients. The purpose of a pharmaceutical composition is to facilitate administration of a compound to an organism and the absorption of the active ingredient, thus displaying biological activity.
Synthesis Method of the Present Invention
[0065] In order to obtain the object of the present invention, the present invention applies the following synthetic technical solutions.
[0066] A process for preparing a compound of formula (I) of the present invention, or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, comprising the following steps:
[0000]
[0000] heating a compound of formula (IA) with a compound of substituted benzofuran derivatives (IB), preferably (R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one in an organic solvent to give a compound of formula (I),
wherein R 1 to R 3 and n are as defined in general formula (I).
[0067] A process for preparing a compound of formula (II), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, comprising the following steps:
[0000]
[0000] heating a compound of formula (IA) with a compound of substituted benzofuran derivatives (IB), preferably (R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one in an organic solvent to give a compound of formula (II),
wherein R 1 , R 2 , R 4 and n are as defined in general formula (II).
[0068] A process for preparing a compound of formula (III), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, comprising the following steps:
[0000]
[0000] heating a compound of formula (IA) with a compound of substituted benzofuran derivatives (TB), preferably (R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one in an organic solvent to give a compound of formula (III),
wherein R 1 , R 2 , R 4 and n are as defined in general formula (III).
[0069] A process for preparing a compound of formula (IV), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, comprising the following steps:
[0000]
[0000] heating a compound of formula (IVA) with a compound of substituted benzofuran derivatives (TB), preferably (R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one in an organic solvent to give a compound of formula (IV),
wherein R 1 to R 3 and n are as defined in general formula (I).
[0070] A process for preparing a compound of formula (V), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, comprising the following steps:
[0000]
[0000] heating a compound of formula (IVA) with a compound of substituted benzofuran derivatives (IB), preferably (R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one in an organic solvent to give a compound of formula (V),
wherein R 1 , R 2 , R 4 and n are as defined in general formula (I).
[0071] A process for preparing a compound of formula (VI), or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or pharmaceutically acceptable salt thereof, comprising the following steps:
[0000]
[0000] heating a compound of formula (IVA) with a compound of substituted benzofuran derivatives (IB), preferably (R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one in an organic solvent to give a compound of formula (VI),
wherein R 1 , R 2 , R 4 and n are as defined in general formula (I).
[0072] The solvent includes, but is not limited to, acetic acid, methanol, ethanol, acetonitrile, tetrahydrofuran, dichloromethane, dimethyl sulfoxide, 1,4-dioxane, water, N,N-dimethylformamide, or N,N-dimethylacetamide, preferably a nonpolar solvent, more preferably acetonitrile.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] FIG. 1 shows the effect of a ROMK inhibitor on urine volume of SD rats;
[0074] FIG. 2 shows the effect of a ROMK inhibitor on urinary sodium excretion of SD rats;
[0075] FIG. 3 shows the effect of a ROMK inhibitor on urinary potassium excretion of SD rats;
[0076] FIG. 4 shows the effect of a ROMK inhibitor on serum sodium of SD rats; and
[0077] FIG. 5 shows the effect of a ROMK inhibitor on serum potassium of SD rats.
DETAILED DESCRIPTION OF THE INVENTION
[0078] The present invention will be further described with the following examples, but the examples should not be considered as limiting the scope of the invention.
[0079] Conditions that are not specified in the examples were the common conditions in the art or the recommended conditions of the raw materials by the product manufacturer. For the reagents which are not indicated, the origin was the commercially available conventional reagents.
EXAMPLES
[0080] The structure of the compounds were identified by nuclear magnetic resonsance (NMR) and/or mass spectrometry (MS). NMR was determined by Bruker AVANCE-400. The solvents were deuterated-dimethyl sulfoxide (DMSO-d 6 ), deuterated-chloroform (CDCl 3 ) and deuterated-methanol (CD 3 OD) with tetramethylsilane (TMS) as an internal standard. NMR chemical shifts (δ) are given in 10 −6 (ppm).
[0081] MS was determined by a FINNIGAN LCQAd (ESI) mass spectrometer (manufacturer: Thermo, type: Finnigan LCQ advantage MAX).
[0082] Yantai Huanghai HSGF254 or Qingdao GF254 silica gel plate was used for thin-layer silica gel chromatography (TLC). The dimension of the silica gel plate used in TLC was 0.15 mm to 0.2 mm, and the dimension of the silica gel plate used in product purification was 0.4 mm to 0.5 mm.
[0083] Yantai Huanghai 200 to 300 mesh silica gel was used as carrier for column chromatography.
[0084] The known raw materials of the present invention were prepared by the conventional synthesis methods in the art, or can be purchased from ABCR GmbH & Co. KG, Acros Organnics, Aldrich Chemical Company, Accela ChemBio Inc., or Dari chemical Company, etc.
[0085] Unless otherwise stated, the reactions were carried out under nitrogen atmosphere or argon atmosphere.
[0086] The term “nitrogen atmosphere” or “argon atmosphere” means that a reaction flask was equipped with a 1 L nitrogen or argon balloon.
[0087] The term “hydrogen atmosphere” means that a reaction flask was equipped with a 1 L hydrogen balloon.
[0088] CEM Discover-S 908860 type microwave reactor was used in microwave reactions.
[0089] Unless otherwise stated, the solution used in the reactions refers to an aqueous solution.
[0090] Unless otherwise stated, the reaction temperature in the reactions refers to room temperature. Room temperature is the optimum reaction temperature which is in the range of 20° C. to 30° C.
[0091] The reaction process was monitored by thin layer chromatography (TLC), and the elution systems included: A: dichloromethane and methanol, B: n-hexane and ethyl acetate, C: petroleum ether and ethyl acetate, D: acetone. The ratio of the volume of the solvent was adjusted according to the polarity of the compounds.
[0092] The elution systems for purification of the compounds by column chromatography and thin layer chromatography included: A: dichloromethane and methanol, B: n-hexane and ethyl acetate, C: n-hexane and acetone, D: n-hexane, E: ethyl acetate. The ratio of the volume of the solvent was adjusted according to the polarity of the compounds, and sometimes a little alkaline reagent such as triethylamine or acidic reagent was added.
Example 1
(R)-5-cyano-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)-4-methoxypicolinamide
[0093]
Step 1
5-bromo-4-methoxypicolinic acid
[0094] Methyl 5-bromo-4-methoxypicolinate 1a (250 mg, 1.01 mmol) was dissolved in 10 mL of a mixture of methanol, tetrahydrofuran and water (V:V:V=3:3:1), and then added with sodium hydroxide (100 mg, 2.5 mmol) and stirred for 2 hours. The reaction solution was concentrated under reduced pressure, and the residues were added with 10 mL of water. The resulting mixture was adjusted to pH 2 by 2M hydrochloric acid and extracted with ethyl acetate (20 mL×3). The organic phase was washed with saturated NaCl solution (15 mL×2), dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure to obtain the crude title compound 5-bromo-4-methoxypicolinic acid 1b (200 mg) as a white solid, which was used in the next step without further purification.
[0095] MS m/z (ESI): 229.9 [M−1].
Step 2
tert-Butyl 4-(5-bromo-4-methoxypicolinamido)piperidine-1-carboxylate
[0096] 5-Bromo-4-methoxypicolinic acid 1b (150 mg, 0.65 mmol), 4-amino-1-tert-butoxycarbonylpiperidine (130 mg, 0.65 mmol), 1-ethyl-(3-dimethylaminopropyl)carbodiimide (190 mg, 1 mmol), 1-hydroxybenzotriazole (20 mg, 0.13 mmol) and triethylamine (0.15 mL, 1 mmol) were dissolved in 20 mL of N,N-dimethylformamide. The reaction mixture was warmed to 50° C. and stirred for 6 hours at 50° C. The reaction solution was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system B to obtain the title compound tert-butyl 4-(5-bromo-4-methoxypicolinamido)piperidine-1-carboxylate 1c (60 mg, 22.4%) as a light yellow oil.
[0097] MS m/z (ESI): 414.1 [M+1].
Step 3
tert-butyl 4-(5-cyano-4-methoxypicolinamido)piperidine-1-carboxylate
[0098] tert-Butyl 4-(5-bromo-4-methoxypicolinamido)piperidine-1-carboxylate 1c (60 mg, 0.15 mmol), zinc cyanide (26 mg, 0.22 mmol) and tetra (triphenylphosphine)palladium (18 mg, 0.015 mmol) were dissolved in 1.5 mL of N,N-dimethylacetamide. The mixture was stirred under microwave for 40 mins at 135° C. The reaction solution was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system B to obtain the title compound tert-butyl 4-(5-cyano-4-methoxypicolinamido)piperidine-1-carboxylate 1d (32 mg, 61.5%) as a colorless oil.
[0099] MS m/z (ESI): 361.2 [M+1].
Step 4
5-cyano-4-methoxy-N-(piperidin-4-yl)picolinamide
[0100] tert-butyl 4-(5-cyano-4-methoxypicolinamido)piperidine-1-carboxylate 1d (32 mg, 0.09 mmol) was dissolved in 5 mL of dichloromethane, and added with 1 mL of trifluoroacetic acid. The reaction mixture was stirred for 1.5 hours. The reaction mixture was concentrated under reduced pressure. The residues were added with 15 mL of methanol, and adjusted to pH 8 by saturated sodium bicarbonate solution. The mixture was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system A to obtain the title compound 5-cyano-4-methoxy-N-(piperidin-4-yl)picolinamide 1e (23 mg, 100%) as a white paste.
[0101] MS m/z (ESI): 261.1 [M+1].
Step 5
(R)-5-cyano-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)-4-methoxypicolinamide
[0102] (R)-4-methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one (25 mg, 0.09 mmol, prepared according to the method disclosed in patent application “WO2010129379”) and 5-cyano-4-methoxy-N-(piperidin-4-yl)picolinamide 1e (23 mg, 0.09 mmol) were dissolved in 5 mL of acetonitrile. The reaction mixture was stirred under reflux for 15 hours. The reaction mixture was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system A to obtain the title compound (R)-5-cyano-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)-4-methoxypicolinamide 1 (4.5 mg, 11.3%) as a light yellow solid.
[0103] MS m/z (ESI): 450.2 [M+1].
[0104] 1 H NMR (400 MHz, DMSO-d 6 ): δ 8.88 (s, 1H), 8.75 (d, 1H), 7.77 (s, 1H), 7.71-7.69 (m, 2H), 5.43-5.40 (m, 2H), 5.35 (s, 1H), 5.08 (s, 1H), 4.09 (s, 3H), 3.78 (s, 1H), 2.95 (s, 3H), 2.38 (s, 1H), 2.27 (s, 3H), 2.25 (s, 2H), 1.72 (s, 4H).
Example 2
(R)-5-cyano-4-ethoxy-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide
[0105]
Step 1
6-chloro-4-ethoxynicotinonitrile
[0106] 4,6-Dichloronicotinonitrile 2a (500 mg, 2.89 mmol) was dissolved in 20 mL of tetrahydrofuran, and added dropwise with 10 mL of a solution of sodium ethoxide (197 mg, 2.89 mmol) in ethanol under 0° C. The reaction mixture was warmed to room temperature and further stirred for 1 hour. The reaction mixture was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system B to obtain the title compound 6-chloro-4-ethoxynicotinonitrile 2b (375 mg, 71%) as a white solid.
[0107] MS m/z (ESI): 183.1 [M+1].
Step 2
tert-butyl 4-(5-cyano-4-ethoxypicolinamido)piperidine-1-carboxylate
[0108] 6-Chloro-4-ethoxynicotinonitrile 2b (375 mg, 2.05 mmol), 4-amino-1-tert-butoxy-carbonylpiperidine (422 mg, 2.05 mmol), palladium acetate (23 mg, 0.1 mmol), 1,3-bis(diphenylphosphino)propane (42 mg, 0.1 mmol), triethylamine (0.57 mL, 4.1 mmol) and 20 mL of acetonitrile were charged in an autoclave. The resulting mixture was subjected to a reaction for 16 hours at 80° C. under 10 bar carbon monoxide. The reaction mixture was filtered. The filtrate was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system A to obtain the title compound tert-butyl 4-(5-cyano-4-ethoxypicolinamido)piperidine-1-carboxylate 2c (645 mg, 84%) as a white solid.
[0109] MS m/z (ESI): 373.2 [M−1].
Step 3
5-cyano-4-ethoxy-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate
[0110] tert-Butyl 4-(5-cyano-4-ethoxypicolinamido)piperidine-1-carboxylate 2c (100 mg, 0.27 mmol) was dissolved in 5 mL of dichloromethane, and added with 1 mL of trifluoroacetic acid. The reaction mixture was stirred for 1 hour. The reaction mixture was concentrated under reduced pressure to obtain the crude title compound 5-cyano-4-ethoxy-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate 2d (110 mg) as a yellow oil, which was used in the next step without further purification.
Step 4
(R)-5-cyano-4-ethoxy-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide
[0111] (R)-4-Methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one (50.7 mg, 0.27 mmol) and crude 5-cyano-4-ethoxy-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate 2d (110 mg, 0.27 mmol) were dissolved in 15 mL of acetonitrile and added with sodium carbonate (56.6 mg, 0.53 mmol). The reaction mixture was warmed to 80° C. and stirred for 48 hours. The reaction mixture was filtered and concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system A to obtain the title compound (R)-5-cyano-4-ethoxy-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide 2 (50 mg, 40%) as a light yellow solid.
[0112] MS m/z (ESI): 465.2 [M+1].
[0113] 1 H NMR (400 MHz, CD 3 OD): δ 8.89 (s, 1H), 8.74 (d, 1H), 7.73 (s, 1H), 7.65 (s, 2H), 5.41 (d, 2H), 5.09 (br, 1H), 4.41 (d, 2H), 3.71-3.85 (m, 2H), 2.95 (br, 2H), 2.41-2.55 (m, 2H), 2.31 (s, 3H), 2.12-2.27 (m, 2H), 1.57-1.81 (m, 4H), 1.40 (t, 3H).
Example 3
(R)-5-cyano-4-(2-fluoroethoxy)-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide
[0114]
Step 1
6-chloro-4-(2-fluoroethoxy)nicotinonitrile
[0115] 2-Fluoro ethanol (150 mg, 2.34 mmol) was dissolved in 10 mL of tetrahydrofuran, sodium hydride was added (281 mg, 7.02 mmol), and the resulting mixture was stirred for 1 hour. 4,6-dichloronicotinonitrile 2a (405 mg, 2.34 mmol) was dissolved in 25 mL of tetrahydrofuran, and added dropwise into the reaction mixture at 0° C. The reaction mixture was warmed to room temperature and stirred for 1 hour. The reaction mixture was quenched by 1 mL of water and concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system B to obtain the title compound 6-chloro-4-(2-fluoroethoxy)nicotinonitrile 3a (210 mg, 45%) as a white solid.
[0116] MS m/z (ESI): 201.1 [M+1].
Step 2
tert-butyl 4-(5-cyano-4-(2-fluoroethoxy)picolinamido)piperidine-1-carboxylate
[0117] 6-Chloro-4-(2-fluoroethoxy)nicotinonitrile 3a (210 mg, 1.05 mmol), 4-amino-1-tert-butoxycarbonylpiperidine (216 mg, 1.05 mmol), palladium acetate (12 mg, 0.05 mmol), 1,3-bis(diphenylphosphino)propane (22 mg, 0.05 mmol), triethylamine (0.29 mL, 2.1 mmol) and 20 mL of acetonitrile were charged in an autoclave. The resulting mixture was subjected to reaction for 16 hours at 80° C. under 10 bar carbon monoxide. The reaction mixture was filtered. The filtrate was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system B to obtain the title compound tert-butyl 4-(5-cyano-4-(2-fluoroethoxy)picolinamido)piperidine-1-carboxylate 3b (140 mg, 34%) as a white solid.
[0118] MS m/z (ESI): 391.1 [M−1].
Step 3
5-cyano-4-(2-fluoroethoxy)-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate
[0119] tert-Butyl 4-(5-cyano-4-(2-fluoroethoxy)picolinamido)piperidine-1-carboxylate 3b (70 mg, 0.18 mmol) was dissolved in 5 mL of dichloromethane, and added with 1 mL of trifluoroacetic acid. The reaction mixture was stirred for 1 hour. The reaction mixture was concentrated under reduced pressure to obtain the crude title compound 5-cyano-4-(2-fluoroethoxy)-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate 3c (80 mg) as a yellow oil, which was used in the next step without further purification.
Step 4
(R)-5-cyano-4-(2-fluoroethoxy)-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide
[0120] (R)-4-Methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one (34 mg, 0.18 mmol) and crude 5-cyano-4-(2-fluoroethoxy)-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate 3c (80 mg, 0.18 mmol) were dissolved in 20 mL of acetonitrile, and added with sodium carbonate (38 mg, 0.36 mmol). The reaction mixture was warmed to 80° C. and stirred for 48 hours. The reaction mixture was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system A to obtain the title compound (R)-5-cyano-4-(2-fluoroethoxy)-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide 3 (10 mg, 12%) as a white solid.
[0121] MS m/z (ESI): 481.2 [M−1]
[0122] 1 H NMR (400 MHz, CD 3 OD): δ 8.93 (s, 1H), 8.79 (d, 1H), 7.82 (s, 1H), 7.71 (d, 2H), 5.41 (d, 2H), 5.14 (br, 1H), 4.89 (t, 1H), 4.77 (t, 1H), 4.72 (t, 1H), 4.65 (t, 1H), 3.71-3.82 (m, 2H), 2.85-3.15 (m, 2H), 2.40-2.54 (m, 2H), 2.31 (s, 3H), 2.12-2.26 (m, 2H), 1.61-1.90 (m, 4H).
Example 4
(R)-5-cyano-4-(difluoromethoxy)-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide
[0123]
Step 1
(2-bromo-5-chloropyridin-4-yl)boronic acid
[0124] 2-Bromo-5-chloropyridine 4a (2 g, 10.4 mmol) was dissolved in 40 mL of tetrahydrofuran, and then added dropwise with 7.8 mL of 2M lithium diisopropylamide under −78° C. The resulting mixture was stirred for 1 hour. Triisopropyl borate (2.94 mg, 15.6 mmol) was added and the reaction mixture was stirred for 30 mins at −78° C. The reaction mixture was then warmed to room temperature and further stirred for 16 hours. 50 mL of 4% sodium hydroxide solution was added. The mixture was stirred for 30 mins. The aqueous phase was separated and adjusted to pH 3 to 4 by 6 M sodium hydroxide solution in an ice-water bath. Then, the aqueous phase was extracted with ethyl acetate (50 mL×2). The organic phases were combined, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to obtain the crude title compound (2-bromo-5-chloropyridin-4-yl)boronic acid 4b (1.3 g, 53%) as a white solid.
Step 2
2-bromo-5-chloropyridin-4-ol
[0125] (2-Bromo-5-chloropyridin-4-yl)boronic acid 4b (1.3 g, 5.51 mmol) was dissolved in 40 mL of dichloromethane, and added with hydrogen peroxide (1.87 mL, 16.5 mmol). The resulting mixture was stirred for 16 hours. The reaction mixture was concentrated under reduced pressure to obtain the crude title compound 2-bromo-5-chloropyridin-4-ol 4c (1 g, 88%) as a white solid.
[0126] MS m/z (ESI): 205.9/207.9 [M+1].
Step 3
2-bromo-5-chloro-4-(difluoromethoxy)pyridine
[0127] The crude 2-bromo-5-chloropyridin-4-ol 4c (320 mg, 1.54 mmol), sodium 2-chloro-2,2-difluoroacetate (470 mg, 3.08 mmol) and potassium carbonate (470 mg, 3.39 mmol) were dissolved in 5 mL of N,N-dimethylacetamide. The reaction mixture was warmed to 120° C. and stirred for 1 hour under microwave. The reaction mixture was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system B to obtain the title compound 2-bromo-5-chloro-4-(difluoromethoxy)pyridine 4d (950 mg, 60%) as a colourless oil.
Step 4
tert-butyl 4-(5-chloro-4-(difluoromethoxy)picolinamido)piperidine-1-carboxylate
[0128] 2-Bromo-5-chloro-4-(difluoromethoxy)pyridine 4d (1.03 g, 3.99 mmol), 4-amino-1-tert-butoxycarbonylpiperidine (800 mg, 3.99 mmol), palladium acetate (45 mg, 0.2 mmol), 1,3-bis(diphenylphosphino)propane (82 mg, 0.2 mmol), triethylamine (1.1 mL, 7.98 mmol) and 30 mL of acetonitrile were charged in an autoclave. The resulting mixture was reacted for 16 hours at 80° C. under 10 bar carbon monoxide. The reaction mixture was filtered. The filtrate was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system B to obtain the title compound tert-butyl 4-(5-chloro-4-(difluoromethoxy)picolinamido)piperidine-1-carboxylate 4e (809 mg, 50%) as a white solid.
[0129] MS m/z (ESI): 404.1 [M−1].
Step 5
[0130] tert-butyl 4-(5-cyano-4-(difluoromethoxy)picolinamido)piperidine-1-carboxylate tert-Butyl 4-(5-chloro-4-(difluoromethoxy)picolinamido)piperidine-1-carboxylate 4e (100 mg, 0.25 mmol), zinc cyanide (57.6 mg, 0.49 mmol) and tetra (triphenylphosphine)palladium (88 mg, 0.07 mmol) were dissolved in 5 mL of N,N-dimethylacetamide. The mixture was stirred under microwave for 30 mins at 170° C. The reaction solution was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system B to obtain the title compound tert-butyl 4-(5-cyano-4-(difluoromethoxy)picolinamido)piperidine-1-carboxylate 4f (83 mg, 85%) as a white solid.
[0131] MS m/z (ESI): 395.0 [M−1].
Step 6
[0132] 5-cyano-4-(difluoromethoxy)-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate tert-Butyl 4-(5-cyano-4-(difluoromethoxy)picolinamido)piperidine-1-carboxylate 4f (250 mg, 0.63 mmol) was dissolved in 5 mL of dichloromethane, and added with 2 mL of trifluoroacetic acid. The reaction mixture was stirred for 1 hour. The reaction mixture was concentrated under reduced pressure to obtain the crude title compound 5-cyano-4-(difluoromethoxy)-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate 4g (540 mg) as a yellow oil, which was used in the next step without further purification.
[0133] MS m/z (ESI): 297.2 [M+1].
Step 7
(R)-5-cyano-4-(difluoromethoxy)-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide
[0134] (R)-4-Methyl-5-(oxiran-2-yl)isobenzofuran-1(3H)-one (57.7 mg, 0.3 mmol), crude 5-cyano-4-(difluoromethoxy)-N-(piperidin-4-yl)picolinamide 2,2,2-trifluoroacetate 4g (260 mg, 0.3 mmol) and N,N-diisopropylethylamine (78.4 mg, 0.61 mmol) were dissolved in 3 mL of ethanol. The reaction mixture was warmed to 135° C. and stirred for 1 hour under microwave. The reaction mixture was concentrated under reduced pressure. The residues were purified by thin layer chromatography (TLC) with elution system A to obtain the title compound (R)-5-cyano-4-(difluoromethoxy)-N-(1-(2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydroisobenzofuran-5-yl)ethyl)piperidin-4-yl)picolinamide 4 (30 mg, 20%) as a white solid.
[0135] MS m/z (ESI): 487.2 [M+1]
[0136] 1 H NMR (400 MHz, CD 3 OD): δ 9.13 (s, 1H), 8.87 (d, 1H), 7.98 (t, 1H), 7.83 (s, 1H), 7.63-7.78 (m, 2H), 5.40 (d, 2H), 5.08 (br, 1H), 3.70-3.81 (m, 2H), 2.96 (br, 2H), 2.40-2.54 (m, 2H), 2.28 (s, 3H), 2.11-2.26 (m, 2H), 1.61-1.75 (m, 4H).
Test Examples
Biological Assay
Test Example 1: The Inhibitory Activity of the Present Compounds on Human ROMK and Rat ROMK Channels
[0137] The method described hereafter was used for determining the inhibitory activity of the present compounds on human ROMK and rat ROMK channels.
1. Materials and Instruments
[0138] (1) FluxOR™ potassium ion channel assay (F10016, Invitrogen)
(2) Ouabain (O3125-1G, Sigma)
[0139] (3) FlexStation3 microplate reader (Molecular Devices)
(4) Human ROMK/HEK293 cell: HEK293 cell line stably expressing the ROMK channel transfected by human ROMK cDNA (NCBI SEQ ID NO. NM-000220.4)
(5) Rat ROMK/HEK293 cell: HEK293 cell line transfected by rat ROMK cDNA (NCBI SEQ ID NO. NM-017023.1) stably expressing the ROMK channel
(6) HEK293 cell line: Cell Bank of Chinese Academy of Sciences, GNHu43
2. Experimental Procedure
[0140] Except for ddH 2 O and Ouabain, all of the experimental reagents are from FluxOR™ Potassium Ion Channel Assay Kit and the formulation methods also refer to the kit instructions.
[0000] (1) Human ROMK/HEK293 cell was seeded on PDL (Poly-D-lysine) coated plates at 20000 cells/well on the previous day;
(2) After overnight culture, the plate medium was discarded; then according to the Fluxor™ Potassium Ion Channel Assay Kit instructions, the dye was added at 100 μL/hole, and then incubated for 90 mins at room temperature;
(3) The dye was then decanted and 1004, of assay buffer containing ouabain (30004) and probenecid were added in each well;
(4) 1 μL of compound or DMSO was added to the corresponding wells, shocked for 30 seconds, and incubated for 30 mins at room temperature;
(5) The plates were placed in a FlexStation3 microplate reader, and then added with stimulation buffer (K 2 SO 4 : Tl 2 SO 4 : 1×FluxOR Chloride-free Buffer: ddH 2 O=3:12:40:125) at 25 μL/well, then the value was read continuously for 5 mins at EX/EM of 490/525 nm immediately; and
(6) The IC 50 of the present compounds on human ROMK channel was obtained by data processing software Graphpad.
[0141] The above procedures were repeated, except for replacing human ROMK/HEK293 cells with rat ROMK/HEK 293 cells, to determine the inhibition IC 50 of the present compounds on rat ROMK channel.
[0142] The inhibitory activity of the present compounds on human ROMK or rat ROMK channel was tested by the assay described above. The IC 50 values are shown in Table 1 below.
[0000] TABLE 1 The inhibitory IC 50 of the present compounds on human ROMK or rat ROMK channels Human ROMK Rat ROMK Example No. IC 50 (nM) IC 50 (nM) 1 40 192 2 28 89
Conclusion: The compounds of the present invention have significant inhibitory activity on human ROMK and rat ROMK channels.
Test Example 2: The Inhibitory Activity of the Present Compounds on hERG
[0143] The method described hereafter is used for determining the inhibitory activity of the present compounds on hERG
1. Materials and Instruments
[0144] (1) FluxOR™ potassium ion channel assay (F10016, invitrogen)
(2) FlexStation3 microplate reader (molecular devices)
(3) hERG/HEK293 cell: HEK293 cell line stably expressing the hERG channel transfected by hERG cDNA (NCBI SEQ ID NO. NM-000238(RC215928, origene)).
2. Experimental Procedure
[0145] Except for ddH 2 O, all of the experimental reagents are from FluxOR™ Potassium Ion Channel Assay Kit and the formulation methods also refer to the kit instructions.
[0000] (1) Human hERG/HEK293 cell was seeded on PDL (Poly-D-lysine) coated plates at 25000 cells/well on the previous day;
(2) After overnight culture, the plate medium was discarded; then according to FluxOR™ potassium ion channel detection requirements operation, the dye was added at 100 μL/hole, and then incubated for 90 mins at room temperature;
(3) The dye was then decanted and 100 μL of assay buffer containing 1004, probenecid were added in each well;
(4) 1 μL of compound or DMSO was added to the corresponding wells, shocked for 30 seconds, and incubated for 30 mins at room temperature;
(5) The plates were placed in a FlexStation3 microplate reader, and then added with stimulation buffer (K 2 SO 4 : Tl 2 SO 4 : 1×FluxOR Chloride-free Buffer: ddH 2 O=2:1:2:5) at 25 μL/well, then the value was read continuously for 5 mins at EX/EM of 490/525 nm immediately; and
(6) The IC 50 of the present compounds on human hERG ion channel was obtained by data processing software Graphpad.
[0146] The inhibitory activity of the present compounds on hERG was tested by the assay described above. The IC 50 values are shown in Table 2 below.
[0000] TABLE 2 The inhibitory IC 50 of the present compounds on hERG Example No. hERG IC 50 (μM) 1 43.7
Conclusion: The compounds of the present invention have a weak inhibitory effect on hERG, which indicates that the compounds of the present invention have a low cardiotoxicity.
Test Example 3: The Effect of the Electrophysiological Manual Patch Clamp on ROMK Potassium Channel
1. Protocol
[0147] The experiment was designed to test the effect of compounds on ROMK potassium channel in HEK 293 in vitro. ROMK potassium channel is stably expressed on the HEK293 cells of the present application. After the potassium ion current was stabilized, the effect of the present compound on the potassium channel was obtained by comparing the potassium current obtained before and after the use of the present compound at different concentrations.
2. Materials and Instruments
[0148] (1) HEK293 cell line: cell bank of Chinese academy of sciences, GNHu43;
(2) Human ROMK/HEK293 cell: HEK293 cell line stably expressing the ROMK channel transfected by human ROMK cDNA (NCBI SEQ ID NO. NM-000220.4);
(3) Extracellular fluid (mM): NaCl, 137; KCl, 4; CaCl 2 , 1.8; MgCl 2 , 1; HEPES, 10; glucose, 10; pH 7.4 (NaOH titration); and
(4) Intracellular fluid (mM): K Aspartate, 130; MgCl 2 , 5; EGTA 5; HEPES, 10; Tris-ATP, 4; pH 7.2 (KOH titration).
[0149] The compounds were purchased from Sigma (St. Louis, Mo.) in addition to NaOH and KOH for acid-base titration.
[0150] Cell culture medium: Ham's F12 medium (Invitrogen), 10% (v/v) inactivated fetal bovine serum, 100 μg/mL hygromycin B, 100 μg/mL Geneticin;
[0000] Manual patch clamp system: HEKA EPC-10 signal amplifier and digital conversion system, purchased from Germany HEKA Electronics;
Micro-control instruments: MP-225; and
Drawing electrode instrument: PC-10 (Narishige, Japan).
3. Experimental Procedure
[0151] Test compounds were dissolved in dimethyl sulfoxide (DMSO) and then stocked at room temperature. On the day of the experiment, test compounds were diluted to the following final concentration (3, 10, 30, 100, 300 nM) using extracellular fluid. The final concentration of the test compounds in DMSO was 0.3%.
[0152] Human ROMK/HEK293 cells were grown in a culture dish containing the above-mentioned cell culture medium and cultured in an incubator containing 5% CO 2 at 37° C. Human ROMK/HEK293 cells were transferred to a round glass plate placed in the culture dish 24 to 48 hours before the experiment, and grown under the same culture medium and conditions as above. The human ROMK/HEK293 cells on each of the round glass plates were required to reach a density in which the vast majority of cells was independent and individual.
[0153] A manual patch clamp system was used for whole-cell current record in this experiment. The round glass plate with human ROMK/HEK293 cells grown on the surface was placed in an electrophysiological recording bath under an inverted microscope. The recording bath was maintained under continuous perfusion with extracellular fluid (approximately 1 mL per minute). The whole-cell patch clamp current recording technique was applied in the experiment. Unless otherwise stated, the tests were carried out at room temperature (˜25° C.). Cells were clamped at −80 mV. The cell clamp voltage was depolarized to +20 mV for 5 seconds to activate the ROMK potassium channel, and then clamped to −50 mV to eliminate inactivation and generate tail current. The tail current peak value was used as the value of the ROMK current. After the ROMK potassium current recorded in the above steps was stabilized under continuous perfusion with extracellular liquid in the recording bath, the drug to be tested was perfused until the inhibition of the drug on the ROMK current reached a steady state. Generally, the reclosing of three consecutive current recording lines was used as the criteria for determining a stable state. After stabilization, the cells were perfused with extracellular fluid until the ROMK current returned to the value before the addition of the drug. One cell can be tested for one or more drugs, or for multiple concentrations of the same drug, but needs to be rinsed with extracellular fluid between different drugs.
4. Data Analysis
[0154] The data were analyzed by HEKA Patchmaster, XLFit and Graphpad Prism data analysis software. The IC 50 values are shown in Table 3 below.
[0000]
TABLE 3
The inhibitory IC 50 of the present compounds on
ROMK potassium channel
Example No.
IC 50 (nM)
1
18.7
[0155] Conclusion: The compounds of the present invention have a strong inhibitory effect on ROMK potassium channel.
Test Example 4: The Effect on hERG Potassium Channel Determined by Electrophysiological Manual Patch Clamp
1. Object
[0156] The object of this experiment is to test the effect of compounds on hERG potassium channel of CHO cells in vitro. In this present invention, hERG potassium channel is stably expressed on the CHO cells. After potassium ion current was stabilized, the effect of the compound on the potassium channel was obtained by comparing the magnitude of potassium current before and after application of different compound concentrations.
1. Materials and Instruments
[0157] (1) CHO cell line: Sophion Biosciense Company Denmark;
(2) hERG/CHO cell: CHO cell line stably expressing the hERG channel transfected human ROMK cDNA (NCBI SEQ ID NO. NM-000238 (RC215928, origene));
(3) Extracellular fluid (mM): EC 0.0.0 NaCl-Ringer's solution, NaCl, 145; KCl, 4; CaCl 2 , 2; MgCl 2 , 1; HEPES, 10; glucose, 10; pH 7.4 (NaOH titration), osmotic pressure ˜305 mOsm; and
(4) Intracellular fluid (mM): IC 0.0.0 KCl-Ringer's solution, KCl, 120; CaCl 2 , 5.374; MgCl 2 , 1.75; EGTA 5; HEPES, 10; Na-ATP 4; pH 7.25 (KOH titration), osmotic pressure ˜305 mOsm.
[0158] The compounds were purchased from Sigma (St. Louis, Mo.) in addition to NaOH and KOH for acid-base titration.
[0000] Cell culture medium: Ham's F12 medium (Invitrogen), 10% (v/v) inactivated fetal bovine serum, 100 μg/mL hygromycin B, 100 μg/mL Geneticin;
Manual patch clamp system: HEKA EPC-10 signal amplifier and digital conversion system, purchased from Germany HEKA Electronics;
Micro-control instruments: MP-225; and
Drawing electrode instrument: PC-10 (Narishige, Japan).
2. Experimental Procedure
[0159] The test compounds were gradiently diluted with dimethyl sulfoxide (DMSO) to 30, 10, 3, 1, 0.3 and 0.1 mM and then stocked at room temperature beforehand. Then, the stock solution was diluted to the following final concentrations (30, 10, 3, 1, 0.3 and 0.1 μM) using extracellular fluid. The final concentration of the test compound in DMSO was 0.1%. All stock solutions and test solutions were ultrasonically oscillated for 5-10 minutes to ensure complete dissolution of the compounds.
[0160] CHO hERG cells were grown in a culture dish containing the above-mentioned cell culture medium and cultured in an incubator containing 5% CO 2 at 37° C. CHO hERG cells were transferred to round glass plates placed in the culture dish 24 to 48 hours before the experiment and grown under the same culture medium and conditions as above. The CHO hERG cells on each of the round glass plates were required to reach a density in which the vast majority of cells was independent and individual.
[0161] A manual patch clamp system was used for whole-cell current record in this experiment. The round glass plate with CHO hERG cells grown on the surface was placed in an electrophysiological recording bath under an inverted microscope. The recording bath was maintained under continuous perfusion with extracellular fluid (approximately 1 mL per minute). The whole-cell patch clamp current recording technique was applied in the experiment. Unless otherwise stated, the tests were carried out at room temperature (˜25° C.). Cells were clamped at −80 mV. The cell clamp voltage was depolarized to +20 mV for 5 seconds to activate the hERG potassium channel, and then clamped to −50 mV to eliminate inactivation and generate tail current. The tail current peak value was used as the value of the hERG current. After the hERG potassium current recorded in the above steps was stabilized under continuous perfusion with extracellular liquid in the recording bath, the drug to be tested was perfused until the inhibition of the drug on the hERG current reached a steady state. Generally, the reclosing of three consecutive current recording lines was used as the criteria for determining a stable state, After stabilization, the cells were perfused with extracellular fluid until the hERG current returned to the value before the addition of the drug. One cell can be tested for one or more drugs, or for multiple concentrations of the same drug, but need to be rinsed with extracellular fluid between different drugs.
4. Data Analysis
[0162] The data were analyzed by HEKA Patchmaster, XLFit and Graphpad Prism data analysis software. The IC 50 values are shown in Table 4 below.
[0000]
TABLE 4
The inhibitory IC 50 of the present compounds on
hERG potassium channel
Example No.
IC 50 (μM)
1
14.95
[0163] Conclusion: The compounds of the present invention have a weak inhibitory effect on hERG potassium channel, which indicates that the compounds of the present invention have a low cardiotoxicity.
Test Example 5: The Pharmacokinetics Assay of the Present Compounds
1. Abstract
[0164] Rats were used as test animals. The drug concentration in plasma at different time points was determined by LC/MS/MS after administration of the compounds to rats. The pharmacokinetic behavior of the present compounds was studied and evaluated in rats.
2. Protocol
2.1 Samples
Compounds of Example 1
2.2 Test Animals
[0165] Four (4) healthy adult Sprague-Dawley (SD) rats, half male and half female, were purchased from SINO-BRITSH SIPPR/BK LAB. ANIMAL LTD., CO, with Certificate No.: SCXK (Shanghai) 2008-0016.
2.3 Preparation of the Test Compounds
[0166] The appropriate amount of the test compounds was weighed, and added with 0.5% CMC-Na to a final volume to prepare a 0.5 mg/mL suspension by ultrasonication.
2.4 Administration
[0167] Following fasting overnight, 4 SD rats, half male and half female were administered intragastrically a dose of 5.0 mg/kg and an administration volume of 10 mL/kg.
3. Process
[0168] Blood (0.1 mL) was sampled from orbital sinus before administration and 0.5 h, 1.0 h, 2.0 h, 4.0 h, 6.0 h, 8.0 h, 11.0 h, and 24.0 h after administration. The samples were stored in EDTA anticoagulation tubes, and centrifuged for 10 minutes at 3,500 rpm to separate the blood plasma. The plasma samples were stored at −20° C. The rats were fed 2 hours after administration.
[0169] The plasma concentration of the test compounds in rats after intragastric administration was determined by LC-MS/MS. Plasma samples were analyzed after pretreatment by protein precipitation.
4. Results of Pharmacokinetic Parameters
[0170] Pharmacokinetic parameters of the present compounds are shown in Table 5 below.
[0000]
TABLE 5
Pharmacokinetics Parameters (5 mg/kg)
Mean
Apparent
Plasma
Area Under
Residence
Distribution
Example
Conc.
Curve
Half-Life
Time
Clearance
Volume
No. 1
Cmax
AUC
T½
MRT
CLz/F
Vz/F
compound
(ng/mL)
(ng/mL * h)
(h)
(h)
(ml/min/kg)
(ml/kg)
Oral
1329 ± 388
9283 ± 3046
3.62 ± 0.33
5.51 ± 0.75
9.82 ± 3.50
3019 ± 841
Test Example 6: The Diuretic Efficacy of ROMK Inhibitors in SD Rats
1. Object
[0171] The diuretic efficacy of compound 1 and positive control drug of ROMK inhibitor on SD rats was evaluated.
2. Methods and Materials
2.1 Test Animals and Feeding Conditions
[0172] Male SD rats were purchased from SINO-BRITSH SIPPR/BK LAB. ANIMAL LTD., CO (Shanghai, China, Certificate No. 2008001647752, License SCXK (Shanghai) 2013-0016). The rats were 120-130 g, and fed at 5/cage, in a 12/12 hours light/dark cycle regulation, at a constant temperature of 23±1° C., humidity of 50˜60%, and free access to water and food. The male SD rats were acclimated to this condition for 7 days before their use in the diuresis experiment.
2.2 Test Drug
Compound 1;
[0173] The structure of the positive control drug is as follows:
[0000]
[0000] 0.9% NaCl solution (500 ml: 4.5 g).
CMC Na: Batch No. 20131022, Sinopharm Group Chemical Reagent Co., Ltd.
[0174] Sodium detection kit: Batch No. 20150203, from Nanjing Jiancheng Biotechnology Company.
Potassium detection kit: Batch No. 20141112, from Nanjing Jiancheng Biotechnology Company.
[0175] The drug dose was calculated according to the tree base.
2.3 the Experimental Design and Method
2.3.1 Animal Grouping
[0176] After adaptive feeding, the animals were grouped as follows:
[0000]
Groups
n
Administration
Normal
10
0.5% CMC (i.g.once)
Compound 1-0.03 mg/kg
10
0.03 mg/kg (i.g.once)
Compound 1-0.1 mg/kg
10
0.1 mg/kg (i.g.once)
Positive control drug
10
0.03 mg/kg (i.g.once)
−0.03 mg/kg
Positive control drug −0.1 mg/kg
10
0.1 mg/kg (i.g.once)
2.3.2 the Experiment Method
[0177] The experiment was carried out according to the method disclosed in PCT Patent Application Publication WO2010129379A1 After adaptive feeding, the rats were placed in metabolism cages and fasted overnight. The rats were weighed and randomly divided into the following groups: blank control group, compound 1 tested drug 0.03 mg/kg group and 0.1 mg/kg group, and the positive control group 0.03 mg/kg and group 0.1 mg/kg, with 10 rats for each group. Each rat was intragastrically administered each compound (ig, 1 ml/kg). The rats in the blank control group were fed with the corresponding solvent. After intragastric administration, the rats were placed in the normal cage. After 30 min, 25 ml/kg normal saline was given. Rats were put into the metabolic cages, and fasting for food and water began immediately. The total urine volume in 4 h was collected and measured. The urinary sodium and urinary potassium excretion in 4 h were also measured. The orbital serum was collected after the collection of urine to test the serum sodium and serum potassium concentrations.
2.4 the Experimental Apparatus
[0178] Room temperature centrifuge: Model 5417C, supplied by Eppendorf.
2.5 Data Representation and Statistical Processing
[0179] The experimental data were expressed as mean±standard deviation (S.D.). The data was statistically compared using the t test of excel. The data between the drug group and the control group were analyzed and compared to determine whether there was a significant statistical significance. *P<0.05 indicates that there is a significant difference between the drug group and the control group, and ** P<0.01 indicates that there is a high significant difference between the drug group and the control group.
3. Result
[0180] The results show that compared with the blank control group, the urine volume for the positive control drug 0.03 mg/kg and 0.1 mg/kg group increased significantly (P<0.05), in which the urine output was increased 1.41 times and 1.46 times, respectively; the urine volume for compound 1 tested drug 0.03 mg/kg group and 0.1 mg/kg group increased significantly (P<0.01), in which the urinary output was increased by 2.76 times and 3.22 times (see FIG. 1 ). The positive control drug and the compound 1 group significantly increased urinary sodium excretion (P<0.01), in which the urinary sodium excretion was increased 1.57 times, 1.65 times, 3.12 times and 3.31 times (see FIG. 2 ). Compared with the normal control group, the urinary potassium for the positive control drug and test drug were slightly elevated, but not statistically significant (see FIG. 3 ). Simultaneously, the serum sodium and potassium for the positive control drug and each test groups were changed a little (P>0.05) (see FIGS. 4 and 5 ).
4. Discussion
[0181] According to the functional character, K+ channels can be divided into the following four types: slow (delay) K+ channels (K channels), fast (early) K+ channels (A channels), Ca2+ activated K+ channels (K (Ca) channels)) and inwardly rectifying K+ channels. The inwardly rectifying K+ channels (Kir) can be further divided into seven types: Kir1 to Kir7, with different KCNJ encoding genes. The renal outer medullary potassium channel (ROMK) belongs to the Kir1 type. There are at least three subtypes of ROMK in rat kidney: ROMK1, ROMK2 and ROMK3. ROMK2 mostly distributes in the thick segment of the medullary loop ascending branch. ROMK1 and ROMK3 are mainly expressed in the collecting tubules.
[0182] The ROMK expressed in the thick segment of the medullary loop ascending branch regulates the secretion and reabsorption of potassium together with Na/K/Cl transporters. The ROMK expressed in the cortical collecting tubules regulates the secretion of potassium together with Na/K transporters. Blocking the ROMK site can promote the secretion of NaCl to the lumen without excessive hypokalemia leading to hypokalemia. It is a good research direction of diuretics for hypertensive patients. This experiment is to explore the diuretic effect of ROMK inhibitors.
[0183] In this experiment, the solubility of the test compound 1 was very good. There was no delamination phenomenon. However, when weighing the positive control drug, there was static electricity, which was not easy to weigh, in the initial grinding, there was clumping and poor solubility. After fully grinding, the solubility improved. The results also show that a single oral administration of compound 1 and positive control drug to rats achieves a significant diuretic and sodium excretion effect compared with the normal group. Moreover, the effect was dose-dependent for each dose of the test compound 1 and the positive control drug.
5. Conclusion
[0184] Compound 1 and the positive control drug both have significant diuretic and sodium excretion effects, but have no effect on serum potassium. However, the diuretic effect of compound 1 is better than that of the positive control drug. The drug efficacy of each group is dose-dependent.
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Pyridinecarboxamide derivatives, preparation methods, and a pharmaceutical uses thereof are provided. In particular, pyridinecarboxamide derivatives represented by general formula (I), wherein the substituents of the formula (I) are defined in the specification are provided. Also provided are a preparation method for the pyridinecarboxamide derivatives of formula (I), a pharmaceutical composition containing the pyridinecarboxamide derivatives, and uses of the pyridinecarboxamide derivatives as therapeutic agents, especially as inhibitors of the Renal Outer Medullary Potassium channel (ROMK) and in the preparation of medicaments for treating and/or preventing hypertension and heart failure.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Italian Application No. VA2004A000003 filed Jan. 23, 2004, incorporated in its entirety by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A COMPACT DISK APPENDIX
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] This invention relates in general to microelectronic devices for studying biological phenomena at, a cellular level and more precisely to a method and a device for confining cells, for example neural cells, on a chip of noninvasive neuroelectronic interfacing.
BACKGROUND OF THE INVENTION
[0005] Individual neurons from different parts of the brain may be taken from animals and cultivated in biologically compatible environments. However, if an ex vivo neural network could be established, it could then be studied by stimulating neurons with electric signals and observing how the live network reacts and modifies itself. This could bring us closer to understanding how a neural network modifies its structure during the learning phase and the rules that govern the way synapses and neurites grow. The analysis of the electro-physiological activity of the neurons in the neural network may allow us to develop artificial prostheses for by-passing injured zones and restore brain functionality, or to realize neuro-diagnostic tools for monitoring the reaction of biological neurons to selected chemical species or newly developed drugs. But in order to reach this objective, we need suitable devices for maintaining a live neural network with electrical stimulation and detection capabilities.
[0006] Specifically, we need a device that can spatially arrange a plurality of live neurons at individual fixed positions with reliable and durable electrical coupling to stimulation and detection circuitry. The device should allow the confined neurons to grow and develop synaptic connections for creating a neural network and communication. For applying and detecting electric signals there must be means for ensuring a stable contact of the body of each spatially confined neuron to an electrode or with a functionally equivalent electrical coupling element, connected to a circuit for stimulating neurons and for detecting electrical signals exchanged among them.
[0007] There are many research teams that study neural activity by stimulating and recording electrical signals coming from distinct zones of a nervous tissue (hippocampus, cortex etc.), but the main difficulty is electrically coupling external stimulation and sensing circuitries to the neurons.
[0008] This is currently established through coupling elements of two kinds: invasive interfaces (electrodes are implanted “in vivo” in a nervous tissue); and noninvasive interfaces (where neural tissue contacts a silicon chip substrate establishing an electrical coupling with an embedded electrode).
[0009] The main drawback of invasive interfaces, typically employing intra-cellular electrodes, is the risk of irremediably damaging the cell during experiments. Moreover, it is very difficult to use more than two electrodes at the same time for stimulating the neural network because the actuators used for correctly positioning the microelectrodes are very cumbersome.
[0010] In order to overcome this problem, effective noninvasive interfaces for coupling neurons to external electronic devices are being earnestly searched and developed. For example, Dr. Roberta Diaz Brinton grew rat hippocampus neurons on a silicon substrate at the University of Southern California. The objective of his experiment was to use hybrid brain-silicon systems for studying the processes by which a brain carries out complex operations, such as pattern recognition.
[0011] According to this methodology, dissociated neurons were placed on a silicon test substrate having an array of electrodes and coated with a material to which the neural cells could stably adhere. The neurons fixed themselves to the silicon substrate and grew, sprouting processes and synaptic connections with other neurons. The growth of the neurons colonies was directable: by using masks, it was possible to predefine paths along which growing neurites would extend. The electrodes onto which the neurons were cultivated were used both for stimulating neurons as well as for monitoring their electrical activity.
[0012] At Caltech (California Institute of Technology), a device called a “neurochip” has been realized in which a network of live brain cells was connected through electrodes on a silicon chip to stimulation and detection circuitry [1] [2]. Neurons having a maximum diameter of about 15 μm were taken from the superior cervical ganglion (SCG) of a rat. The “neurochip” had three main features: a well formed in the silicon substrate into which a neural cell was confined, an overhanging grillwork for trapping the cell body inside the well, and an electrode in contact with the trapped neuron.
[0013] The disclosed “neurochip” was composed of sixteen trapezoidal wells, closed at the top by an overhanging grillwork of patterned heavily doped silicon, constituting a 4×4 array, realized on a silicon wafer by photolithography and “micromachining” of the silicon crystal. On the bottom face of the silicon wafer, a predefined 4×4 array of gold electrodes that closed the bottom of the wells provided a stable electrical contact with the entrapped cell bodies. The surface of the electrodes at the bottom of the wells was covered with platinum black for reducing contact impedance with the body of the neural cell.
[0014] The entrapment grillwork was designed to permit the introduction of an embryonic neural cell into each well and prevent that cell from escaping. At the same time, the grillwork allowed neurites to sprout through the apertures of the grillwork and connect to other neurons to form a live neural network.
[0015] A variety of different grillwork patterns have been tested to prevent cell escape. In a recent release of the neurochip, depicted in FIG. 1 , a MEMS structure forms a sort of canopy above the well. The overhanging grillwork above the etched cavity in the silicon substrate has openings through which neurites may sprout.
[0016] FIG. 2 is a SEM (Scanning Electron Microscope) picture of the grillwork and a cross sectional schematic of the trapping well closed by the retention grillwork showing the openings through which the neuron grows and eventually develops its neurites.
[0017] The height of the openings through the grillwork (micro tunnels) depends on the thickness of the patterned nitride layer that constitutes the overhanging grillwork. An appropriate choice of the dimensions of these micro tunnels allows neurons to grow out of the well cavity, but preventing their escape. Experiments have shown that the crucial parameter in preventing neuron escape through the growth “microtunnels” is not their breadth but their extension (length), that is the thickness of the grillwork nitride layer.
[0018] However, reliable entrapment of neurons by means of an insurmountable overhanging grillwork that obstructs the well opening have the disadvantage of not allowing the replacement of dead cells without irreparably damaging the confining device.
[0019] At the “Max Planck Institute for Biochemistry” in Munich, Germany, Peter Fromherz and Gunther Zech carried out experiments on neurons of “ Lymnaea Stagnalis” [ 3] that, being an invertebrate (a kind of slug), has neurons with a relatively large body that contact the underlying interfacing substrate very well. These neurons, even in small numbers, were capable of reproducing normal biological functions.
[0020] The neurons were cultivated onto a silicon chip, shown in FIG. 3 . The letters S, G and D indicate the source, gate and drain terminals, respectively, of an integrated Filed Effect Transistor (FET). The white scale line is 20 μm long.
[0021] The chip was covered with a layer of silicon oxide for preventing electrochemical phenomena at the neuron-substrate contact surface and also for creating a homogeneous and inert rest surface for the neurons. Neurons were confined on the silicon substrate by means of a polyamide picket fence.
[0022] In order to ensure a noninvasive neuron-silicon interface, a two-way electrical coupling was established by means of the FET and a stimulator (ST). The stimulator (ST) was substantially constituted by a P doped zone onto an N doped silicon region covered by a thin layer of silicon oxide. The source and drain terminals of the transistor were realized in distinct P doped regions with a gate area covered by a thin gate oxide layer not topped by any metal gate electrode layer.
[0023] The stimulator (ST) provided a capacitive coupling between the chip and the neuron, while the transistor, integrated in the silicon under the neuron body, sensed the extra-cellular voltage.
[0024] FIG. 4 shows a neuron grown on the device of FIG. 3 after having been cultivated for three days. FIG. 5 is a microscope image of neural cells (dark circles) each confined by a six picket fences of polyamide. Some pickets of adjacent fences have combined, forming a single picket of elongated cross-section. The light gray lines that originate from the cells are neurites grown on the surfaces of the chip that connect the neurons among them. The radially extending straight lines are the traces of the connecting metal lines of the stimulators and sensing transistors.
[0025] By electrically exciting a neuron (via the stimulator), an electrical activity is induced in another neuron of the network that modulates the current in the transistor underneath it, thus amplifying the tenuous electrical signal. Such a detected variation of potential indicates that an electrical synapse has been established between the two neurons.
[0026] Notwithstanding the effectiveness of these devices, reliable and durable spatial confinement of the neural cells is precarious because the neurons tend to escape the picket fence.
[0027] The recurrent problem in designing these devices is to reliably prevent cell escape, but still allow cell growth, and to reliable couple the cells to electrodes (or alternate stimulation and detection means), preferably on an easily micromachinable material such as a monocrystalline silicon chip (wafer). The fact that the confined cell may not properly adhere to the surface of the substrate and thus fail to remain in stable contact with the electrical stimulation and detection elements may impede the stimulation and the monitoring of exchanged electrical messages. The known interfacing structures discussed above represent the best compromise currently available, but better devices are still needed.
BRIEF SUMMARY OF THE INVENTION
[0028] It would be highly desirable to have a device for confining neural cells on a semiconductor chip for noninvasive microelectronic interfacing that in addition to satisfying the above discussed requisites, would also allow the substitution of any single neuron at any phase of its growth within a confinement cavity without damaging the device.
[0029] To all these important and often contrasting requisites, the present applicants have found an effective answer based on the realization of a device that includes an overhanging retention grating that, in contrast to the known “static” grillwork structures, may be elastically deformed in a reversible manner by forcing a certain electric current therethrough to uncover or widen the obstructed aperture of the well and permit introduction of a cell into the confinement cavity.
[0030] Fundamentally, the overhanging grating for retaining the growing neural cell in the confinement cavity includes at least a pair of coplanar and substantially parallel members (traverses) of conducting material, separated by a certain gap, spanning the full width of an opening of the well cavity, each terminating with at least an enlarged portion or pad, connectable to an electrical power source for forcing a current along the parallel extending members.
[0031] Depending on whether the currents in the two parallel elongated traverses flow in the same direction or in opposition directions, either a repulsive or an attractive force is induced, which flexes the portion of the portion of the two parallel conductors hanging over the opening to uncover or widen the aperture. Besides being induced by electromagnetic effect, the flexing may be also partly induced by thermal elongation of traverses spanning across the opening, as a consequence of the heating by Joule effect of the two parallel traverses having their ends suitably restrained.
[0032] The two parallel conductive elongated members of the retention grating of this invention may even deliberately have different cross sectional areas for providing different thermal elongation in the two members. Accordingly, for the same electric current circulated in series in the two parallel members, the Joule heat produced in the slender (essentially more resistive) of the two will be greater than the heat produced in the other member of much larger cross section. The augmented thermal elongation of the slender member produces axial compressive stresses that accentuate the swaying of the slender traverse in the same direction that is immediately caused by the electromagnetically induced repulsive force.
[0033] Optionally, the desired direction of swaying of the slender traverse because of the axial compressive stress due to thermal elongation may be predetermined by defining the elongated slender traverse with a slight (biasing) curvature.
[0034] According to yet another embodiment, two substantially rectilinear and parallel conductive members are defined in a way to form an elongated cantilever fork with a substantially uniform narrow separation slit between them. One of the two arms constituting the cantilever fork is made much slender than the other arm, in order to provide a different thermal elongation of the two arms upon circulating an electric current in series along the two arms of the fork. The elongated fork, including its end bridge portion, is unrestrained. The two arms extend in a cantilever manner from their respective terminal pads of relatively large areas that remain mechanically connected to the substrate through a residual electrically insulating layer, as will be better described later.
[0035] The elongated cantilever fork hangs parallel over the flat surface of the substrate, at a height of separation that may be generally comprised in the range of 0.5 to 3 μm, as appropriate for the size of the cell being studied.
[0036] Upon forcing an electric current in series along the two arms of the cantilever fork, by connecting their two end pads to a power source capable of forcing a certain current, the elongated cantilever fork grating flexes sideways uncovering the aperture or, more practically, several aligned apertures of wells, normally partly or completely occluded by the free end portion of the elongated overhanging cantilever fork grating.
[0037] The dimensions of the coplanar parallel traverses of electrically conducting material are designed to ensure that the electromechanically and/or thermal elongation induced mechanical stress does not exceed the elastic limit of the material of the traverses. The elastic memory of the material ensure the re-closing of the apertures upon ceasing to force a certain electric current along the traverses.
[0038] Electrical coupling means with the entrapped cell body for stimulating the neuron and for detecting neural activity may be embedded in the walls or at the bottom of each confinement well, according to any of the known techniques of establishing an effective electrical coupling between the trapped cell body and the stimulating and/or detecting circuitry.
[0039] For example, an appropriate stimulation/detection electrode may be arranged at the bottom of the cavity according to the arrangement illustrated in FIG. 2 .
[0040] Of course, other means of establishing such a coupling, including the formation of metal-oxide-semiconductor transistor structures and integrated stimulating electrodes according to the approach disclosed in the above mentioned publication of the Max Plank Institute for Biochemistry and depicted in FIG. 3 , may be implemented for electrically interfacing with the entrapped neuron.
[0041] The present device may be integrated into a semiconductor device for analyzing the functioning of live neural networks together with circuits for conveying electrical stimulating pulses to selected neurons and for detecting electrical activity of other neurons caused by the stimulation.
[0042] The above summary of the present invention is not intended to represent each embodiment or every aspect of the present invention. For example, the device can be used to study any cell type of interest. It has particular application to tissue engineering, where the arrangement of different cells types must be controlled during growth of the tissue. For example, different cell types can be directed to grow in different directions using the appropriate surface coating materials and/or the entire tissue can be appropriately seeded with neuronal pathways as needed for the tissue type. The tissue can then be released from the device using the electrical gating means described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 is a microscope image of a “neurochip.”
[0044] FIG. 2 shows a grillwork of a “neurochip” and a sectional view that illustrates its structure.
[0045] FIG. 3 is a SEM picture of a silicon substrate with picket fences of polyamide for containing a neuron.
[0046] FIG. 4 is a SEM picture of a neuron entrapped by pickets of polyamide of the chip of FIG. 3 .
[0047] FIG. 5 illustrates the growth of neurites after two days in the culture onto a chip of FIG. 3 .
[0048] FIG. 6 shows a well cavity of a confinement device according to an embodiment of this invention.
[0049] FIG. 7 is a view, from the well cavity side, of the retention grating assembly of the confinement device according to an embodiment of this invention.
[0050] FIG. 8 shows the upper face of the retention grating assembly of FIG. 7 .
[0051] FIG. 9 is a view of a complete confinement device composed of a well covered with an electrically deformable overhanging retention grating assembly.
[0052] FIG. 10 shows the two parallel traverses that compose the retention grating of FIG. 9 , elastically bent sideways for widening the aperture there between.
[0053] FIG. 11 shows an array of wells formed in the substrate of the neurochip.
[0054] FIG. 12 is a detail sectional view of a well of the array of FIG. 12 , showing the stimulation/detection electrode at the bottom of the well cavity.
[0055] FIG. 13 is a scheme of a system for analyzing the functioning of a live neural network cultivated on a chip of this invention.
[0056] FIGS. 14 and 15 are a cross sectional and plan view, respectively, of an alternative form of confinement cavity that may be formed in a neurochip substrate for cultivating neurons.
[0057] FIG. 16 shows the constitution of a silicon substrate in which buried cavities as the one depicted in FIGS. 15 and 16 may be formed by special bulk micromachining techniques.
[0058] FIG. 17 shows the differences of electrochemical half-cell voltage depending on the conductivity type and concentration of the dopant, in an acid electrolyte solution used for selectively etching silicon domains having a certain dopant concentration.
[0059] FIG. 18 shows the formation of trench holes reaching down to the p+buried epitaxial layer for electrolitically etching the p+ silicon.
[0060] FIG. 19 is a SEM picture of the ongoing selective etching of the p+silicon.
[0061] FIG. 20 shows the structure after leaching with KOH solution the porous oxidized silicon residue of the electrolytic etching.
[0062] FIGS. 21 and 22 are respectively a layout view and an isometric view of a retention grating of a confinement device, according to an embodiment of this invention.
[0063] FIGS. 23 and 24 are respectively a layout and an isometric view showing the elongated retention gratings (microactuators), each extending over a plurality of aligned openings of buried confinement cavities formed in the neurochip substrate.
[0064] FIG. 25 is a partial enlarged isometric view of the free end of a microactuator grating occluding the opening of a confinement cavity formed in the neurochip substrate.
[0065] FIGS. 26-42 illustrate the process of fabrication of a neural cell confinement device according to an embodiment of this invention.
[0066] FIGS. 43-45 illustrate how several aligned apertures, completely or partly occluded by the overhanging cantilever grating (microactuator) may be completely opened by electrically forcing a sideway sway of the elongated cantilever grating for introducing neural cells in respective wells of the neurochip. The cells remain confined therein by returning the overhanging cantilever grating to its rest position.
[0067] FIGS. 46-57 illustrate the modeling of an overhanging elongated cantilever grating (microactuator) of polysilicon, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0068] The effectiveness of an electrically deformable retention grating has been proven using a simulation and analysis tool implementing a technique of finite element modeling and coupled multi-physics analysis. With this technique, it is possible to model a continuous body with a set of elements (finite elements). By applying appropriate boundary conditions (mechanical constraints, electrical, electromagnetic and thermo-electrical solicitations) that simulate the real environment in which the system functions, it is possible to predict the behavior of the grating to verify mechanical sturdiness, reliability and compliance to design specifications.
[0069] Basically, the confinement device for a neural cell includes a well 2 formed in the substrate 1 , a sample embodiment of which is shown in FIG. 6 and a retention grating subassembly 3 , a sample embodiment of which is shown in FIGS. 7 and 8 .
[0070] Both parts may be separately realized by common micromachining techniques of Bulk micromachining and of Surface micromachining and successively bonded together to form a complete spatial confinement device for cultivating neural cell.
[0071] “Bulk micromachining” techniques allow the manufacture of transducers, interfacing microdevices and special components by electrochemically excavating a monocrystalline silicon substrate.
[0072] With these sophisticated fabrication technologies it is possible to control accurately the dimensions and the form of cavities produced even at buried locations in a silicon substrate by controlling the progression of selective channel and/or electrochemical etching.
[0073] In the sample embodiment of FIG. 6 , the well 2 produced in or through a silicon substrate chip 1 , has a truncated-pyramidal shape, but it may be realized even in other shapes by using anisotropic etching techniques.
[0074] The well cavity 2 may be anywhere between 10 μm to 40 μm deep, the area at the truncated bottom may range from 30 μm 2 to 400 μm 2 , and the area of the well opening may range from 400 μm 2 to 3000 μm 2 . These dimensions are generally suitable for the confinement of neural cells that are normally used in neural network studies and for promoting a stable contact of the trapped neuron body with the bottom of the well that, in the embodiment shown, has an electrode 4 for stimulating the neuron and sensing electrical activities of the trapped cell.
[0075] In contrast to “Bulk micromachining” techniques, the so-called “Surface micromachining” techniques, such as the technique used for realizing the overhanging retention grating 3 of FIGS. 7 and 8 , are additive processes by which functional features of the structure are realized over the surface of the silicon substrate.
[0076] An electrically deformable retention grating of this invention may be separately fabricated on a thin silicon slice 1 c in the form of the subassembly depicted in FIGS. 7 and 8 , that may then be bonded over the thicker silicon substrate of the neurochip, in juxtaposition with a well already formed therein. The fabrication sequence avails itself of common fabrication steps such as: depositing a layer of insulating silicon nitride over the silicon surface; depositing a thin sacrificial oxide layer over the deposited nitride layer; defining by photolithography the desired grating elements; depositing a layer of conductive polycrystalline silicon (“polysilicon” or briefly “poly”); and selectively etching the oxide.
[0077] FIG. 8 shows the patterned metal lines 7 and 8 for electrically connecting the two traverses of conductive polysilicon 5 and 6 , constituting the retention grating 3 , to an electrical power supply capable of forcing through the traverses a certain electric current that will flow in opposite directions along the two arms of the fork structure of the grating.
[0078] A view of a single confinement device realized on a neurochip made according to a first embodiment of this invention is shown in FIG. 9 . As depicted, the electrically deformable retention grating subassembly rests on a plurality of perimetral legs 1 b , in the form of cubes of about 1 μm side defined by masked etching of the rear surface of the thin silicon slice 1 c , on which the retention grating structure is separately fabricated. The bases of the cubes are eventually bonded to the surface of the substrate 1 of the neurochip to fix the overhanging electrically deformable retention grating over a respective confinement well 2 . The spaces of about 1 μm between adjacent legs 1 b , aligned along the whole perimeter of the overhanging structure, provide innumerable radially extending channels of about 1×1 μm cross section, through which the confined neuron may extend processes and neurites over the surface of the neurochip to eventually establish synapses.
[0079] The neurochip will include an array of confinement devices of FIG. 9 formed on the monocrystalline silicon substrate 1 , for example according to a spatial arrangement of the relative wells 2 shown in FIG. 11 .
[0080] According to the embodiment illustrated in FIGS. 6-12 , the two extremities of the parallel traverses 5 and 6 of conductive polysilicon, forming the electrically deformable retention grating, are restrained at both their ends and are electrically connected at one extremity by a conductive bridge portion of polysilicon. Such a preferred arrangement forces an electric current serially along one traverse and back along the other traverse through metal lines 7 and 8 , connected to an electric power supply.
[0081] Referring to the illustrations of FIGS. 9 and 10 , the different conducting cross sectional areas of the two parallel traverses 5 and 6 , in which the same electric current flows in series, determines a stronger heat generation by Joule's effect along the slender (essentially more resistive) traverse 5 and the compressive stress eventually causes an accentuated swaying (sideway bending) of the slender traverse 5 away from the other traverse 6 because of the induced repulsive force between the two conductors (traverses) crossed by electric current in opposite directions.
[0082] It is also possible to predetermine the direction in which the slender traverse 5 will sway by defining it with a slight curvature that will be accentuated by the thermal elongation compressive stress.
[0083] In any case, the aperture defined by the grating is widened by forcing a current through the structure, the widening being sufficient to permit introduction of an embryonal neuron cell into the well cavity 2 , under the deformable retention grating 3 .
[0084] Naturally, the footprint of the retention grating 3 on the opening area of the confinement well 2 will be designed such to leave relatively narrow apertures for permitting the neuron to sprout processes and neurites out of the confinement trap eventually connecting with other neurons to form a live neuronal network over the neurochip substrate.
[0085] Alternatively, the electrically deformable retention grating 3 may be directly fabricated over the well aperture by a fabrication process similar to the one described in [1] or in [4].
[0086] Thermal elongation coefficient in polysilicon is about 2.5 PPM/° C. and the thickness of the polysilicon layer from which the two traverses are patterned, may range from 1 μm to 10 μm and have a width ranging from about 0.2 μm to 5.0 μm.
[0087] By proper design, the mechanical stresses that are induced in the traverses that form the retention grating of this invention, will be limited within a maximum value such to remain safely below the elastic limit of the constituent conductive material (e.g. doped polysilicon) in order to ensure the return of the elastically deformed traverses to their original form and dimensions upon interrupting the flow of the electric current. This is accomplished by properly designing the cross sections and form of the overhanging traverses in function of a certain design current to be forced therethrough to cause their swaying.
[0088] FIG. 12 shows how a stimulating/detecting electrode 4 may be embedded in the cavity or well 2 of the confinement device according to the embodiment illustrated in the preceding figures. Bulk micromachining of the monocrystalline silicon substrate is continued until etching through the whole thickness of the substrate and an electrically insulating silicon nitride layer 9 , deposited over the back surface of the silicon wafer, and over which is deposited a layer of gold 10 , practically stopping the etching on the deposited and already patterned gold layer 10 . The contact surface is preferably coated with a platinum layer 11 and the so realized electrode at the bottom of each well cavity is connected through the patterned gold lines 10 to the stimulating circuitry and to the detection circuitry.
[0089] For further reducing the electrical contact impedance with the neuron body entrapped in the well, the contact surface may also be provided with a top coating of platinum black.
[0090] A neurochip analyzer with a functioning of a neural network is schematically shown in FIG. 13 . Each stimulation/detection electrode formed at the bottom of truncated pyramid confinement wells according to the embodiment described above is connected to an interface circuitry with a neuronal stimulating unit and to the interfacing circuitry with a monitoring unit of electrical activities of the neurons.
[0091] The electrically induced swaying of elongated traverses may be practiced according to alternative embodiments. For instance, instead of relying on a sideways bending of elongated traverses spanning across the aperture of the confinement cavity and mechanically restrained at both ends onto the surface of the substrate, under the action of electromagnetic attraction or repulsion force and/or of axial stresses caused by thermal elongation of the parallel conducting members mechanically restrained at both ends, the same result may be achieved by relying on the swaying on the plane of a cantilever elongated fork grating.
[0092] The cantilever fork grating may be composed of a slender am and a much wider aim connected at their free end by a bridge portion, the arms of the fork grating being restrained only at their feedthrough electrical connection pad extremities, which are the only parts solidly fastened onto the surface of the substrate.
[0093] Upon forcing a current along the two parallel arms of the cantilever fork grating, the different thermal elongation of the two arms of different conducting cross section causes the elongated cantilever fork to sway sideways on the plane of overhang over the surface of the neurochip substrate bending toward the quadrant contiguous to the arm of larger cross section.
[0094] According to this alternative embodiment, the cantilever grating is made relatively long, the portion farther away from the retraining pads (that is the free end portion) overhanging over a plurality of aligned openings of as many confinement cavities produced in the substrate. Thus, at rest, the cantilever fork grating occludes substantially all of the openings, although remaining spaced from the surface of the substrate by a distance of about 1 μm to permit neurites to grow out of the occluded opening, passing underneath the overhanging cantilever grating, and spread out over the surface of the substrate to connect with other spatially confined neurons.
[0095] According to this alternative embodiment of the invention, the confinement well is preferably in the form of a “buried” cavity that is produced with a generally ellipsoid shape at a depth of about 10 μm from the surface of the substrate. An access hole of generally square cross section with side of about 8 μm is formed by dry etching the silicon at the center of the buried cavity to be formed. The access hole is used for electrolitically etching selectively the p+ domains of a p+ doped buried epitaxial layer grown on the n-type substrate, and successively, to remove the previously oxidized porous silicon residue left by the selective electrolytic etch, by wet chemical leaching of the oxidized porous silicon mass, thus realizing an open buried confinement cavity suitable for hosting an embryonal neuronal cell.
[0096] A certain number of aligned openings of as many confinement cavities formed in the substrate are eventually occluded by an elongated cantilever fork grating overhanging above the openings, which may be caused to bend sideway sufficiently to shift its free end portion off the openings, which are then accessible by a suitable neuronal cell introduction tool.
[0097] FIGS. 14 and 15 shows a sample design of a single confinement cavity 2 formed in a substrate 1 and having a central opening 2′. The indicated dimensions may be for example: A=8 μm; B=6 μm; C=25 μm; D=10 μm; E=F=70 μm. Optionally, numerous holes 11 of relatively small diameter may be etched from the surface of the substrate down to the confinement cavity uniformly distributed around the central access opening 2 ′ to offer possible routes through which the neuron may sprout.
[0098] Electrical coupling of the confined neuron body with the stimulation/detection may be established, as shown in FIGS. 14 and 15 , in the same manner as in the prior embodiment, by embedding a platinum electrode 11 , preferably coated with platinum black, in the substrate 1 at the bottom of the buried confinement cavity 2 , connected by patterned gold lines 10 , defined on the bottom surface of the substrate over an insulating layer of silicon nitride 9 .
[0099] The buried microcavities into which a neurocell is cultivated may be realized by bulk micromachining a silicon substrate that includes epitaxially grown layers purposely doped with different types of dopants and/or with different concentration of dopant.
[0100] Preferably, as shown in FIG. 16 , a suitable monocrystalline silicon substrate includes a starting wafer 1 w of n − doped silicon, onto which is firstly grown an epitaxial layer 1 ′ of p + doped silicon of thickness coinciding with the height of the buried cavity to be created, for example of about 15 μm, onto which a second epitaxially grown layer 1 ″ of n − silicon is successively grown.
[0101] The buried p + silicon layer between n − silicon is anodically etched using an electrolytic solution of hydrofluoric acid. The selectivity of anodic dissolution of silicon rests on the different contact potential (half cell potential) that is strongly dependent on the type and concentration of the dopant.
[0102] FIG. 17 shows the differences of half-cell potential between a hydrofluoric acid electrolyte and silicon upon varying the type of dopant (p or n) and its concentration. The selective electrolytic etching process produces porosities in the silicon practically leaving a highly porous residual oxidized silicon structure in the region progressively reached by the electrolytic solution.
[0103] The electrolytic etching of selected buried regions of the silicon substrate may be made possible for example by forming holes (trench holes) sufficiently deep to reach down to the middle of the buried p + layer at the desired locations, so that the electrolytic etching solution may reach it, as depicted in FIG. 18 .
[0104] FIG. 19 is a SEM picture of the ongoing electrolytic erosion of the buried layer of p + silicon, through access holes. A subsequent thermal treatment in an oxidizing atmosphere will promote a substantially complete oxidation of the highly porous residual mass of silicon in the cavity ready to be finally leached away in a KOH solution for emptying the cavity, producing a structure such as the one schematically depicted in FIG. 20 . The single cantilever retention grating, according to this alternative embodiment of the invention, acts primarily by thermal elongation in function of the Joule's heat produced by forcing a current along a cantilever fork structure composed of two arms of conductive polycrystalline silicon.
[0105] FIGS. 21 and 22 are a layout and a perspective view of a single electrically deformable retention grating (microactuator), according to this alternative embodiment. The structure is restrained only in correspondence of the two enlarged pad portions 5′ and 6′. The cantilever fork portion is constituted by a pair of elongated arms 5 and 6 of conductive polysilicon joined together at their free end. The arm 6 has a larger width than the slender arm 5 for a substantial portion of its length, only a neck portion near the respective pad 6 ′ being made as slender as the parallel arm 5 , in order to provide for a neck zone of reduced mechanical resistance to bending stresses 6 ″.
[0106] As schematically shown in FIGS. 23, 24 and 25 , a neurochip will normally have an array of buried cavities 2 , each having an opening. Each elongated cantilever grating (microactuator) 3 of conductive polysilicon is defined such that its free end portion occludes the central openings 2 ′ of a number of aligned buried cavities 2 formed in the neurochip substrate 1 .
[0107] FIG. 25 is an enlarged detail view of a farthest opening 2 ′ that is occluded by the free end tip of the microactuator 3 . According to this embodiment, the length of the cantilever arms 5 and 6 of each microactuator is 912 μm, the width of the slender arm 5 and of the neck portion 6 ″ of the wider arm 6 is 1 μm and the thickness of the patterned polysilicon layer constituting the microactuator grating 3 is 1 μm. The neck region 6 ″ has a length of about 60 μm. The width of the wider arm 6 is 6 μm. The size of the pads 5 ′ and 6 ′ is 43.5×12×1 μm. Under each of the two pads 5 ′ and 6 ′ there is an electrically isolating layer of silicon nitride, the dimension of which are of about 40×8×1 μm, that mechanically connect the polysilicon to the surface of the silicon substrate 1 . In practice, the elongated cantilever fork microactuator composed of the two arms 5 and 6 is spaced from the surface of the substrate by about 1 μm.
[0108] The process flow for fabricating a neurochip according to this embodiment starting from a monocrystalline silicon wafer is illustrated in the series of Figs. from 26 to 42 . FIGS. 26 and 27 show the successive epitaxial growth of a p + , layer and successively of an n-layer for constituting the silicon substrate 1 of the neurochip. FIGS. 28 and 29 show the deposition of a layer of photoresist (resist) and the photolithographic definition of apertures 2 ′ of a generally square form through the resist mask.
[0109] In a preferred alternative to forming access holes as previously described in relation to FIGS. 18, 19 and 20 , a p + dopant implantation is performed in the n − silicon under the square apertures of the resist mask, as depicted in FIGS. 30 and 31 . FIGS. 32 and 33 show the resulting structure after having removed the resist mask. As visible in the partly cut away view of FIG. 33 , the heavy p + dopant implanted regions extend down to merge with the buried epitaxial p + silicon layer.
[0110] FIG. 34 is a partial cut away view showing the resulting structure after having completed the electrolytic selective etching of the p + domains of the crystalline silicon, leaving the electrolytically etched regions of the would be buried ellipsoid cavity 2 and of the communicating channel of generally square cross section 2 ′ in the form of a highly porous and partly oxidized residual silicon structure.
[0111] Thereafter, as depicted in FIGS. 35 and 36 , a layer of silicon nitride (nitride) is deposited over the whole surface and on the nitride layer a conductive polycrystalline silicon layer (poly) is deposited. Then on the surface of the wafer a new layer of photoresist is deposited and photolithographically defined to leave the resist mask of the grating as shown in FIGS. 37 and 38 over the polysilicon layer.
[0112] The polysilicon is chemically etched to geometrically define the electrically conductive microactuator structure 3 , as depicted in FIG. 39 . Thereafter, the resist mask is removed leaving the patterned microactuator structure 3 completely defined as shown in FIG. 40 .
[0113] Thereafter, a controlled chemical etching with a hydrofluoric acid solution of the nitride is conducted, as illustrated in FIG. 41 , so that the exposed nitride and the nitride present under the extended fork portion of the microactuator is completely removed leaving the fork portion cantilevering above the underlying substrate while, by virtue of the relatively large areas of the two pad portions 5 ′ and 6 ′ of the two arms of the fork structure 3 , the etching of the nitride encroaches only for a short distance under the polysilicon of the two pads 5 ′ and 6 ′. Indeed, by the time the nitride under the elongated relatively slender fork portion is completely removed, the etching has only marginally encroached under the definition edges of the relatively large area pad portions. By timely interrupting the chemical etch of the nitride, a consistent portion of mechanically restraining nitride layer will remain under the pad portions of the cantilever polysilicon microactuator.
[0114] After this step of wet chemical etching of the nitride, the openings 2 ′ of the buried cavities under the overhanging cantilever fork of the microactuator are uncovered and a final wet leaching in a KOH solution removes the mass of oxidized porous silicon residues in the whole cavities and the final structure of the entrapment device is as depicted in the partly cut away view of FIG. 42 .
[0115] FIGS. 43 to 45 schematically depict how the elongated cantilever fork grating (microactuator) is caused to bend sideways by forcing an electric current through the polysilicon cantilever fork for determining a different thermal elongation by the Joule's heat generated by the current in the two parallel arms of the fork, purposely made with markedly different conductive cross sections.
[0116] FIG. 44 shows the introduction through the openings no longer occluded by the microactuator of an embryonal neuronal cell into each cavity. FIG. 45 shows how the cultivated neuronal cells, statically confined in respective cavities, send out processes and neurites passing underneath the overhanging cantilever fork grating that remain spaced about 1 μm from the flat surface of the substrate.
[0117] The deflection of the microactuators upon forcing an electric current through them has been determined through finite element analysis using the simulation program ANSYS 6.0. The physical properties of the materials constituting the microacruator system where as reported in the following Tables 1, 2 and 3.
TABLE 1 Physical Properties of the polysilicon Young's modulus 169 GPa Poisson's coefficient 0.22 Resistivity 2.3 e −11 TΩ μm Thermal expansion coefficient 2.9 e −6 l/K Heat conductivity 150 e 6 pW/μmK Density 2.33 e −15 Kg/μm 3
[0118]
TABLE 2
Physical Properties of silicon nitride
Young's modulus
247.5 GPa
Poisson's coefficient
0.24
Resistivity
1 e 5 TΩ μm
Thermal expansion coefficient
3.3 e −6 l/K
Heat conductivity
30 e 6 pW/μmK
Density
3.1 e −15 Kg/μm 3
[0119]
TABLE 3
Physical Properties of monocrystalline silicon
Young's modulus
165 GPa
Poisson's coefficient
0.22
Resistivity
2.3 e −11 TΩ μm
Thermal expansion coefficient
2.5 e −6 l/K
Heat conductivity
157 e 6 pW/μmK
Density
2.3 e −15 Kg/μm 3
[0120] A microactuator 3 formed on a 25 μm thick silicon substrate, for occluding four aligned square openings of 8 μm side length was discretized as a free mash of 82 , 125 elements as depicted in FIG. 47 (SOLID 98 ). Geometry, location of nodes and coordinate systems of the elements, are depicted in FIG. 46 . Such an element (SOLID 98 ) of discretization has been selected as particularly suited for carrying our thermal, electrical and structural analysis.
[0121] FIGS. 48-57 show the results of the distinct analysis, in particular of the deflection along the cantilevered fork microactuators, the temperature distribution reached in the cantilevered fork microactuator and of the equivalent tensile stress according to Von Mises.
[0122] FIGS. 48 and 49 show that the value of deflection in correspondence of each of the four aligned openings that are normally occluded by the microactuator is amply sufficient to permit the introduction of embryonal neuronal cells into the buried cavities.
[0123] FIGS. 50, 51 and 52 show the temperature distribution reached along the elongated cantilevered fork of polysilicon. As may be recognized, the temperatures reached in the elongated cantilever fork grating remain in a range that is substantially biocompatible for a safe introduction embryonal neuronal cells into the buried cavities. The electrical current that is forced by applying a voltage of 1 Volt to the pads of a microactuator is 0.4790×10 7 pA and the heat that is generated by Joule's effect along the polysilicon fork microactuator is 0.3538×10 7 pW.
[0124] FIG. 53 shows the distribution of the equivalent tensile stress in the whole microactuator structure according to Von Mises; such equivalent tensile stress values represent mono-dimensional tensile stresses equivalent to the real three-dimensional stress state, in order to determine the yield stress of the structure. The highest value of equivalent tensile stress acting in the microactuator structure occurs in correspondence of the nitride layer that electrically insulates the electrically conductive polysilicon cantilever fork of the microactuator and restrains it by binding it at one end to the surface of the silicon substrate.
[0125] FIG. 54 is an enlarged view of the zone of maximum equivalent tensile stress. In order to verify that the mechanical integrity of the system is never jeopardized, the maximum equivalent tensile stress must be compared to the yield stress of the stressed material(s). The silicon nitride under the polysilicon terminal pads of the two arms of the cantilever fork, is the material that is most stressed and its yield stress is of about 150 MPa. Since the maximum tensile stress found to be acting on the nitride is about 85 MPa, there would appear to be an ample safety margin to ensure the mechanical resistance of the microactuator system.
[0126] Along the elongated cantilevered fork portion of the microactuator of polysilicon, the maximum equivalent tensile stress that is reached is 22 MPa and also this value appears to be amply tolerable by the polysilicon with a yield stress of about 500 MPa. The measured maximum equivalent tensile stress in relation to the yield stress of the polysilicon means the mechanical behavior of the microactuator is well within the range defined by Hook's law, that is a linear-elastic behavior.
[0127] FIGS. 55 and 56 show the distribution of the stresses along the cantilever fork actuator of polysilicon causing substantially rectilinear deflection of the cantilever fork portion freeing the access to the buried cavities. In particular, FIG. 56 shows the typical butterfly distribution of the longitudinal stresses consequent to the deflection of the cantilever microactuator localized in the neck zone in proximity of the anchoring pads of the two arms of the cantilever fork. Finally FIG. 57 shows the voltage distribution along the arms that form the cantilever fork actuator.
[0128] Although various embodiments of the method and apparatus of the present invention have been illustrated in the accompanying drawings and described above, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth herein.
[0129] The following materials are each incorporated in their entirety by reference.
[1] J. A. Wright, et al., “Towards a Functional MEMS Neurowell by Physiological Experimentation”, Tech. Digest: ASME 1996 International Mechanical Engineering Congress and Exposition, DSC - Vol. 59, Atlanta, Ga., pp. 333-338, November 1996. [2] www.its.caltech.edu/˜pinelab. [3] G. Zeck, P. Fromherz, “Noninvasive neuroelectronic interfacing with synaptically connected snail neurons immobilized on a semiconductor chip,” PNAS, Vol. 98, No. 18, 10457-10462 (2001). [4] Maher M. P., et al., “The neurochip: a new multielectrode device for stimulating and recording from cultured neurons”, J. Neurosci. Methods 1999; 30: 45-56.
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The invention is directed to a microdevice for containing electrically coupled cells while allowing their growth that allows the addition or removal of cells from their containment by providing an actuatable gate. When the gate is actuated, for example with electric current, the cells may be added or removed from their containment. The invention may be applied to a neurochip or any device for growing cells in a defined spatial arrangement.
This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 CFR 1.72( b ).
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RELATED APPLICATIONS
[0001] THIS APPLICATION CLAIMS THE BENEFIT OF PRIOR PROVISIONAL APPLICATION SER. NO. 60/503,124 UNDER 35 U.S.C. §119(e) AND HEREBY SPECIFICALLY INCORPORATED BY REFERENCE IN ITS ENTIRETY
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] NOT APPLICABLE
REFERENCE A “MICROFICHE APPENDIX”
[0003] NOT APPLICABLE
FIELD OF THE INVENTION
[0004] This invention relates to ready-to-assemble components having brackets attached thereto and method to use brackets to easily assemble components, such as furniture.
BACKGROUND OF THE INVENTION
[0005] Assembling furniture is ordinarily complicated. Present technology for assembling furniture is labor and part intensive. Presently, a piece of furniture will have many component parts and requires several tools for assembly. Moreover, with present technology, assembly of furniture usually requires more than one person.
[0006] Other ready to assemble furniture systems utilize location dependent brackets that multiply the effort needed to assemble the furniture components and that intensify the complexity of the process.
[0007] Presently, most furniture is assembled by the seller because of the complexity of assembling. Thus, furniture is handled fully or most fully assembled which creates bulky cargo that takes up a considerable amount of space and is difficult to transport.
[0008] Additionally, when one part of a piece of furniture is damaged, the entire product must be returned instead of the damaged part. For example, when the frame of the arm of a couch is defective, the entire couch must be returned.
[0009] Regarding other ready-to-assemble furniture systems for furniture, all entail many component parts, are not stable and require considerable time to assemble. See e.g., Cwik U.S. Pat. No. 4,459,920 and Boycott, et al., U.S. Pat. No. 5,671,974.
BRIEF SUMMARY OF THE INVENTION
[0010] This invention provides a bracket assembly for interconnecting components made of a receiving bracket and an engaging bracket. The engaging bracket is made of an elongated riser having an inner surface and an outer surface. A plurality of flanges extend from the elongated riser to form a line of intersection. The elongated riser is configured to extend beyond the plurality of flanges to form a cantilevered projection. The cantilevered projection is made of a first portion and a second portion. The first portion extends along the line of intersection. The receiving bracket is made of a riser having an inner surface and an outer surface and a plurality of flanges. The first portion of the cantilevered projection of the engaging bracket is configured to contact the inner surface of the receiving bracket. The plurality of flanges preferably include an aperture sized to receive an attachment means. In one embodiment, the elongated riser is made of two spaced apart vertical members and a top member forming a hollow internal section.
[0011] The bracket assembly of this invention is made of two main parts: a receiving bracket and an engaging bracket. In the preferred embodiment, the receiving bracket is made of a riser that is formed from two spaced apart vertical members connected with a receiving top member. The spaced apart vertical members and top member form the hollow internal section of the receiving bracket. At least one flange, but preferably to two coplanar flanges, extend perpendicularly from the vertical members. The flange preferably includes at least one aperture to receive an attachment means. The aperture allows the receiving bracket to be fixedly attached to a component. The second main part of the bracket assembly is an engaging bracket. In the preferred embodiment, the engaging bracket is made of an elongated riser that is formed from two spaced apart vertical members connected with an engaging top member. At least one flange, but preferably two coplanar flanges, perpendicularly extends from one of the vertical members and has at least one aperture. A portion of the engaging top member projects beyond the at least one flange to form a cantilevered projection. The cantilevered projection is sized to fit in the receiving internal section of the receiving bracket.
[0012] The inner surface of the receiving bracket is configured to contact the outer surface of the engaging bracket elongated riser. In the preferred embodiment, the receiving bracket has an aperture in the riser that is sized to receive a locking means. In the preferred embodiment, the engaging bracket has an aperture in the elongated riser which is sized to receive a locking means. In the preferred embodiment, two coplanar parallel flanges of the receiving bracket off-set two coplanar parallel flanges of the engaging bracket, upon assembly. In this way, various furniture components can be secured together.
[0013] Additionally, this invention provides a system for a ready to assemble furniture piece made of a plurality of bracketed furniture components having at least one bracket being either an engaging bracket or a receiving bracket, whereby the bracketed furniture components are interconnected through a receiving bracket on one furniture component with accommodating engaging bracket on second furniture component.
[0014] This invention discloses bracketed furniture components that are easily shipped and ready to assemble on arrival without much labor or specialized tools. This invention discloses unique brackets, which form a bracket assembly, that may be placed at any location on the various furniture components. More specifically, this invention provides a method to assemble furniture involving the steps of: providing a plurality of bracketed furniture components and connecting the bracketed furniture components by forming bracket assemblies between the plurality of bracketed furniture components. These brackets are preferably attached by bolts into predrilled holes in furniture panels, but may be attached by any other means as desired by one skilled in the art.
[0015] More specifically, this invention relates to a plurality of bracketed furniture components interconnected by forming bracket assemblies. For example, the bracket components needed to assemble a chair or small couch can include a furniture arm component having a back side arm panel; a front side arm panel; and a side arm panel positioned interconnectingly to the back side arm panel and the front side arm panel, wherein at least one of the panels has at least one engaging or receiving bracket attached thereto; a furniture base component having a first and second side base panels having an exterior and interior surface; a front base panel; and a rear base panel, wherein at least one of the panels has at least one engaging or receiving bracket attached thereto; a furniture seat component having a first and second side seat panel; a front seat panel; and a rear seat panel, wherein at least one of the panels has at least one engaging or receiving bracket attached thereto; a furniture back component having two side back panels wherein at least one of the panels has at least one engaging or receiving bracket attached thereto. The brackets are not location dependent. One skilled in the art may place the engaging brackets and receiving brackets at any location on the furniture components that allows for the furniture components to be interconnected by forming bracket assemblies. Additionally, the number of total bracket assemblies used to interconnect furniture components will vary as desired by one skilled in the art.
[0016] An assembled furniture piece is made by fixedly interconnecting a plurality of furniture components. In one embodiment of a chair, the assembled furniture piece has two furniture arm components each having a back side arm panel having a means to support a receiving bracket, substantially perpendicular to the back side arm panel; a front side arm panel; and a side arm panel positioned interconnectingly to the back side arm panel and the front side arm panel, the side arm panel having a plurality of receiving brackets and a plurality of engaging brackets. The chair further includes a furniture base component having a first and second side base panels having an exterior and interior surface, wherein a plurality of receiving brackets are attached to the exterior and interior surfaces of the first and second side base panel; a front base panel; and a rear base panel. The chair further includes a seat component having a first and second side seat panel wherein the first and second side panels include a plurality of engaging brackets; a front seat panel; and a rear seat panel. The chair further includes a back component having a first and second side seat panel wherein the first and second side panels include a plurality of engaging brackets; a front seat panel; and a rear seat panel; wherein the plurality of engaging brackets of the horizontal side arm panels of each of the furniture arm components are connected to a receiving bracket on the side base panel of the furniture base component; wherein the engaging brackets of the first and second side seat panels of the furniture seat component interconnect with receiving brackets on the back vertical side arm panel of each of the furniture arm components; wherein a plurality of engaging brackets attached thereto to the side back panels of the furniture back component interconnect with receiving brackets attached to the back vertical side arm panel of each of the furniture arm component and the first and second side base panels of the furniture base component.
[0017] This invention further provides a method to assemble furniture having arm, base, seat and back components, which involves the steps of providing two arm components having a plurality of engaging and receiving brackets positioned to connect with corresponding brackets on another component; providing a base component having a plurality of receiving brackets positioned to connect with corresponding brackets on another component; providing a seat component with a plurality of brackets to connect with corresponding engaging brackets on another component; providing a back component with a plurality of engaging components to connect with corresponding receiving brackets on another component; connecting engaging brackets on the arm components with receiving brackets on the base component; connecting engaging brackets on the seat component with receiving brackets on the arm components; and connecting engaging brackets on the back component with receiving brackets on the arm components and the seat component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic view of a receiving bracket.
[0019] FIG. 2 is a schematic view of an engaging bracket.
[0020] FIG. 3 is a schematic view of a bracket assembly.
[0021] FIG. 4A is a schematic top view of a receiving bracket.
[0022] FIG. 4B is a schematic side view of a bracket assembly.
[0023] FIG. 4C is a schematic view of a receiving bracket and an engaging bracket.
[0024] FIG. 5A is a schematic top view of a receiving bracket and a compressible material.
[0025] FIG. 5B is a schematic side view of a receiving bracket and a compressible material.
[0026] FIG. 5C is a schematic view of a receiving bracket and a compressible material.
[0027] FIG. 6A shows a schematic view of the assembly process involving two arm components and a base component.
[0028] FIG. 6B shows the result achieved by the assembly of two arm components and a base component.
[0029] FIG. 7A shows a schematic view of the assembly process involving the seat component and the result in FIG. 6B .
[0030] FIG. 7B shows the result achieved by the assembly of the seat component, the base component and two arm components.
[0031] FIG. 8 shows a schematic view of the assembly process involving the back component and the result in FIG. 7B .
[0032] FIG. 9 shows the result achieved by the assembly of the back component, the seat component, the base component and two arm components.
[0033] FIG. 10A shows a schematic view of a connected table support connector.
[0034] FIG. 10B shows a schematic view of a disconnected table support connector.
[0035] FIG. 11A shows a schematic view of a connected headboard and bedrail.
[0036] FIG. 11B shows a top schematic view of a headboard and bedrail.
[0037] FIG. 11C shows a front schematic view of a headboard and bedrail.
[0038] FIG. 11D shows a right schematic view of a headboard and bedrail.
[0039] FIG. 12A shows a schematic side view of a receiving bracket and pole.
[0040] FIG. 12B shows a schematic side view of a sign connected to a pole via a bracket assembly.
[0041] FIG. 12C shows a schematic view of a sign with engaging bracket and pole with receiving brackets.
[0042] FIG. 13A is a schematic view of a portion of a casket.
[0043] FIG. 13B is a schematic view of a portion of a casket.
[0044] FIG. 13C is a schematic view of a portion of a casket.
[0045] FIG. 13D is a schematic view of a portion of a casket.
DETAILED DESCRIPTION OF THE INVENTION
[0046] Referring now to FIGS. 1-3 , the bracket assembly 5 is made of a receiving bracket 2 and an engaging bracket 4 . Now referring to FIG. 1 , a receiving bracket 2 is made of a riser 34 . The riser 34 has an inner surface 44 and an outer surface 45 . The riser 34 may be straight, orthogonal, horizontal, sloped or curved. The riser 34 forms hollow internal section 20 . The receiving bracket 2 also includes a plurality of flanges 1 and 3 .
[0047] In the preferred embodiment, two coplanar parallel flanges 1 and 3 perpendicularly extend from the riser 34 . In the preferred embodiment, two spaced apart vertical members 34 A extend from a receiving top member 35 to form the riser 34 . In this embodiment, the vertical riser 34 A is straight and orthogonal. Receiving brackets 2 are preferably two and a half inches in width and two inches in length, but may be any size as desired by one skilled in the art. Receiving brackets 2 are preferably made of steel or iron although other materials, such as plastic or a synthetic modification thereof, may be used as desired by one skilled in the art. The engaging bracket 2 can be made integrally with a component.
[0048] In a preferred embodiment, the receiving bracket 2 is made of at least one planar flange 1 having an aperture 6 to receive an attachment means, such as a bolt, but other attachment means, such as spot welding or clamping, may be used as desired by one skilled in the art. At least one aperture 6 is preferably positioned in the center of each of the substantially parallel flanges 1 and 3 allowing for the receiving bracket 2 to be attached to a component (not shown in FIG. 1 ). A lock-down aperture 22 is positioned on the receiving bracket 2 to allow a locking means, such as a bolt, to contact the engaging bracket 4 to form a secure bracket assembly 5 , but any other locking means may be used as desired by one skilled in the art. In this way, one bracketed component is interconnected with a second bracketed component.
[0049] Referring to FIG. 2 , an engaging bracket 4 is made of an elongated riser 36 having an inner surface 46 and an outer surface 47 . The elongated riser 36 may be straight, orthogonal, horizontal, sloped or curved. A plurality of flanges 23 and 24 perpendicularly extend from the elongated riser 36 . The plurality of flanges 23 and 24 form a line of intersection 48 with the elongated riser 36 . The elongated riser 36 is configured to extend beyond the plurality of flanges 23 and 24 to form a cantilevered projection 39 . The cantilevered projection 39 is made of two portions. A first portion 40 and a second portion 41 . In the first portion 40 , the line of intersection 48 extends past the plurality of flanges 23 and 24 to form an outer surface sized to contact the inner surface 44 of the receiving bracket 2 . Additionally, the cantilevered projection 39 has a second portion 41 which tapers and narrows where the line of intersection 48 has been cut away allowing for easy assembly of the engaging bracket 4 and receiving bracket 2 .
[0050] In the preferred embodiment, two coplanar parallel flanges 23 and 24 extend from two spaced apart vertical members 36 A. In the preferred embodiment, the two spaced apart vertical members 36 A are straight and orthogonal. The spaced apart vertical members 36 A extend from the engaging top member 38 . The term riser can refer generically to a bracket having an external surface and a hollow internal section. More specifically, the terms two spaced apart vertical members refers to the preferred embodiment where the riser 36 is formed from two spaced apart members 36 A and a top member 38 .
[0051] Engaging top member 38 projects beyond at least one flange 23 to form a cantilevered projection 39 . The cantilevered projection 39 has a tapered guide portion 41 to allow ease of initial assembly between engaging bracket 4 and receiving bracket 2 . The cantilevered projection 39 is sized to fit, with minimal clearance in receiving bracket internal section 20 . In the preferred embodiment, the engaging bracket 4 is made of at least one planar flange 23 having an aperture 11 to receive attachment means, such as a bolt. Any other attachment means, such as spot welding or clamping, may be used as desired by one skilled in the art. In the preferred embodiment, two coplanar parallel flanges 1 and 3 of the receiving bracket 2 off-set two coplanar parallel flanges 23 and 24 of the engaging bracket 4 upon assembly. Engaging brackets 4 are preferably two and a half inches in width and four inches in length but can be any size as desired by one skilled in the art. Engaging brackets 4 are made of steel or iron although other materials, such as plastic or a synthetic modification thereof, may be used as desired by one skilled in the art. The described shape of the receiving bracket 2 and engaging bracket 4 are constant but the overall size may change. The receiving bracket 4 can be integrally made with the component.
[0052] Now referring to FIG. 3 , a bracket assembly 5 is shown. The bracket assembly 5 is formed of a receiving bracket 2 and an engaging bracket 4 which are placed in contact. The stability of the bracket assembly 5 is based upon contact between the outer surface 47 of elongated riser 36 of the engaging bracket 4 and the inner surface 44 of riser 34 of the receiving bracket 2 . Additionally, the stability of the bracket assembly 5 is based on contact between the first portion 40 of the cantilevered projection 39 of the engaging bracket 4 with the inner surface 44 of the riser 34 of the receiving bracket 2 . Additionally, the stability of the bracket assembly 5 can be based on contact between outer surface 45 of riser 34 of the receiving bracket 2 being in contact with the surface onto which the receiving bracket 2 is mounted.
[0053] Now referring to FIGS. 4 A-C, alternative engaging and receiving brackets are shown. The inner surface 44 and riser 34 of the receiving bracket 2 are sized to contact the outer surface 45 of the engaging bracket 4 . In particular, the stability of the bracket assembly 5 is increased by the contact of the inner surface 44 of the receiving bracket 2 with the first portion 40 of the cantilevered projection 39 of the engaging bracket 4 .
[0054] Additionally, the strength of the bracket assembly 5 can be increased by providing an interference fit between the receiving bracket 2 and engaging bracket 4 . An interference fit occurs when the receiving bracket 2 is mounted on a material, such as wood. Wood will compress on the open side 20 of receiving bracket 2 to create a tight fit. Additionally, an interference fit occurs when the receiving bracket 2 is mounted to a material dissimilar to the engaging bracket 4 material. Similarly, a compressible layer of material, such as rubber can be placed between the receiving bracket and the material to which the receiving bracket is mounted.
[0055] Now referring to FIG. 5A -C, the interference fit can be enhanced by relying on the compressibility of the material onto which the receiving bracket 2 is mounted, such as wood. Wood will compress on the open side 20 of the receiving bracket 2 to create a tight fit. Similarly, a compressible layer of material 50 can be placed between the receiving bracket and the material onto which the receiving bracket 2 is mounted if the material to which the bracket is mounted, i.e., steel, has inadequate compressibility for this purpose.
[0056] The bracket assembly 5 is further strengthened by lock down aperture 22 wherein a locking means such as a bolt is used to secure the receiving bracket 2 to engaging bracket 4 . Any other locking means may be used as desired by one skilled in the art. The lock down aperture 22 is positioned to allow a locking means, such as a bolt to contact the cantilevered portion 39 of engaging bracket 4 .
[0057] The receiving bracket 2 and engaging bracket 4 are attached to panels which are formed into components. The components assemble to form furniture, signage and caskets. The terms “receiving” and “engaging” when used to describe a bracket refer to the shape of a bracket and not to the motion of the assembly process. A furniture component is at least one panel having at least one engaging or receiving bracket attached thereto. In a preferred embodiment, a furniture component is made of a plurality of panels. A furniture component is fixedly attached to another furniture component by forming bracket assemblies 5 between the furniture components. The furniture components with at least one engaging or receiving bracket are referred to as a bracketed furniture components. A furniture component is the basic building block of this system. Furniture will be shipped as bracketed furniture components.
[0058] Now referring to FIGS. 6A-9 , the system and method to assemble a chair is shown. In this illustrative embodiment, the ready to assemble furniture piece 25 is made of five basic furniture components 10 , 12 , 14 and 16 including two opposing arm components 10 , a base component 12 , a seat component 14 , and a back component 16 . Depending on the styling of the furniture, more or less components can be used. These components are interconnected through receiving brackets 2 and engaging brackets 4 attached to the panels or made integrally with the panel. The bracketed furniture components 10 , 12 , 14 and 16 are preferably made of a plurality of furniture panels, such as 7 , 8 , 9 , 13 and 14 . A furniture component may be made of single panel as desired by one skilled in the art. A furniture panel is any part of the frame in which a bracket is attached, but not limited to wood; a panel can include other materials, such as steel and aluminum for example. Receiving brackets 2 and engaging brackets 4 are attached to the furniture components 10 , 12 , 14 and 16 in designated positions depending on the type and design of the ready to assemble furniture piece 25 desired. The brackets 2 and 4 are not location dependent. One skilled in the art may place the engaging brackets 4 and receiving brackets 2 at any location on the furniture components that allows for the furniture components to be interconnected by forming bracket assemblies 5 . The brackets can be attached anywhere on the panels as long as they position interlock with a corresponding bracket on another component. The number, shape and size of the arm components 10 , the base component 12 , the seat component 14 and back component will vary depending on the type and design of the ready-to-assemble furniture piece 25 desired. Also, the number of total bracket assemblies 5 used to interconnect furniture component will vary as desired by one skilled in the art. The number of receiving brackets 2 and engaging brackets 4 attached on the furniture panels 7 , 8 , 9 , 13 and 15 will vary depending type and design of the ready-to-assemble furniture piece 25 desired.
[0059] A ready to assemble furniture piece 25 could be made of different bracketed components that those disclosed in this illustrative embodiment. For example, the bracketed component could be a table top, table leg, cabinet back, cabinet front, cabinet drawers, etc.
[0060] Referring to FIG. 6A , a portion of chair or small couch is shown. More specifically, two furniture arm components 10 are shown. The arm components 10 are made of differing materials and vary in size depending on the type and design of the ready to assemble furniture piece 25 desired. The arm component 10 is made of three major elements: a back side arm panel 7 , a front side arm panel 17 ; and a side arm panel 8 . A back side arm panel 7 includes a means to support a receiving bracket, such as a substantially perpendicular member 26 . The receiving bracket 2 is attached by nails through aperture 6 to the perpendicular member 26 , but other attachment means may be used as desired by one skilled in the art. The receiving bracket 2 of the back side arm panel 7 is preferably attached between the middle and top of the back side arm panel 7 . The front side arm panel 17 is substantially parallel to the back side arm panel 7 and is connected to the side arm panel by a plurality of support members 27 . The side arm panel 8 is substantially perpendicular to the back side arm panel 7 and front side arm panel 17 , and is connected to both. The side arm panel has a plurality of receiving brackets 2 and a plurality of engaging brackets 4 attached thereto. The brackets are positioned to connect with corresponding brackets on another furniture component to form a bracket assembly. A bracket assembly can be strengthened by applying an adhesive, bolt or screw to lock down aperture 22 . The base component 12 is made of a first side base panel 9 and a second side base panel 30 . The base component 12 is also made of a front base panel 28 and a rear base panel 29 . The first side base panel 9 and second side base panel 30 has an interior and exterior surface to which engaging brackets 4 and receiving brackets 2 are attached.
[0061] FIG. 6B depicts the result achieved by the assembly of two opposing arm components 10 and a base component 12 . More specifically, two arm components 10 are contactingly moved adjacent to base component 12 . A plurality of engaging brackets 4 attached to the horizontal side arm panel 8 are inserted into receiving brackets 2 on the exterior surface of the first side base panel 9 and second side base panels 30 of the base component 12 .
[0062] Referring to FIG. 7A , the seat component 14 is made of a first and second side seat panels 13 . A plurality of engaging brackets 4 are vertically mounted on the exterior of each side seat panel 13 . In the preferred embodiment, two sets of engaging brackets 4 are attached near the front and rear sections of the side seat panels 13 allowing for the seat component 14 to lock with the arm components 10 upon assembly. The seat component 14 also includes a front seat panel 31 and rear seat panel 32 . The seat panels 13 , 31 and 32 are interconnected at right angles to form a frame. The receiving brackets 4 on the horizontal side arm panel 8 , and arm component 10 are positioned to receive engaging bracket 4 on side seat panel 13 of seat component 14 .
[0063] FIG. 7B depicts the result achieved by the assembly of the seat component 14 , the base component 12 and the two opposing arm components 10 .
[0064] Referring to FIG. 8 , the back component 16 is made of two side back panels 15 . An engaging bracket 4 is vertically mounted on the exterior of each side back panels 15 near the middle section of each side back panel 15 allowing for the back component 16 to interconnect with the arm components 10 upon assembly. An engaging bracket 4 is vertically mounted on the interior of the side back panels 15 in the lower section of each side back panel 15 allowing for the back component 16 to lock with the base component 12 upon assembly. The back component 16 is further made of a back panel 33 that is substantially perpendicular and attached to the two side back panels 15 .
[0065] FIG. 9 depicts the ready to assembled furniture piece 25 . The ready to assemble furniture piece 25 , a chair, is preferably made of furniture components 10 , 12 , 14 and 16 including the back component 16 , the seat component 14 , the base component 12 and two arm components 10 . Each furniture component 10 , 12 , 14 and 16 is made of furniture panels 7 , 8 , 9 , 13 and 15 which are preferably wooden but may be made of other materials, as desired by one skilled in the art. The furniture components can be upholstered, allowing the brackets to be attached to the exterior of the upholstery or can be upholstered when assembled.
[0066] The furniture components 10 , 12 , 14 and 16 are assembled by interconnecting the receiving brackets 2 and engaging brackets 4 which together form bracket assemblies 5 . The number of bracketed assemblies used will vary depending on the styling of the furniture. At least one receiving bracket 2 or engaging bracket 4 is attached to furniture panels 7 , 8 , 9 , 13 and 15 of each furniture component 10 , 12 , 14 and 16 .
[0067] In relation to the presently illustrative configuration, it should be understood that the ready to assemble furniture piece 25 is readily adaptable to all types of furniture pieces including but not limited to sofas, sleepers, loveseats, chairs, and motion furniture. Moreover, the ready to assemble furniture piece is readily adaptable to most types and designs of furniture including but not limited to leather, fabric, show wood, loose cushion, single cushion, single back and split back. This system is not exclusively intended for upholstered furniture use, but can be used in other areas of the furniture industry, such as cabinets and tables.
[0068] More specifically, as shown in FIGS. 10A and 10B a table support connection is shown. The table support 81 has a plurality of receiving brackets 2 attached around the table support 81 . A table leg 83 has an engaging bracket 4 attached. The receiving bracket 2 and engaging bracket 4 are positioned to allow the table leg 83 to connect with table support 81 .
[0069] In the preferred embodiment, there are four receiving brackets 2 attached equidistantly around the table support 81 , but more or less brackets may be used as desired by one skilled in the art. The four receiving brackets are connected to four engaging brackets 4 to affix the table legs 83 to a table support 81 .
[0070] Additionally, in FIGS. 11 A-D, bedpost and bedrail connections are shown. In FIG. 11A , a bedrail 93 is attached by a bracket assembly 5 to a bedpost 91 . FIGS. 11B-11D show cutaway sections of the connection viewed from above ( FIG. 11B ), the side ( FIG. 11C ) and along the axis of the bedrail ( FIG. 11D ).
[0071] In FIGS. 12A, 12B and 12 C, signage connection is shown. More specifically, a pole 101 has a receiving bracket 2 attached thereto. An engaging bracket 4 is attached to the back surface of a sign 103 . The sign is attached to the pole 101 through bracket assembly 5 .
[0072] Referring to FIGS. 13 A-D, the receiving brackets 2 and engaging brackets 4 can be used to assemble a casket. In FIG. 13D , a bracket assembly 5 combines the components to form a casket.
[0073] The bracket assembly and system is advantageous because it allows the assembly of all types of furniture by a single individual. Moreover, the present invention is advantageous because it allows assembly at any place with no tools required for assembly and in approximately one to two minutes. Unlike present technology which is complicated and labor and part intensive, the self-assembly bracket and system has no loose parts to assemble. The required hardware for the present invention is only the receiving brackets 2 and engaging brackets 4 placed at integral parts on the ready to assembly furniture piece 25 .
[0074] Although the forgoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be obvious that certain changes and modifications can be made which are within the full scope of the invention.
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The invention discloses unique brackets, which form a bracket assembly that may be placed at any location of various components to form an assembly piece, such as furniture. An assembled furniture piece made of furniture panels interconnected with attached engaging and receiving brackets is provided. The engaging and receiving brackets are positioned on components to facilitate the connection of the components. A method to assemble furniture having preformed arm, base, seat and back components is provided. This method of assembly saves on shipment costs, and facilitates the repair of damaged furniture.
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CROSS REFERENCE TO RELATED APPLICATION
This is a divisional of U.S. Application Ser. No. 08/551,841 filed Nov. 6, 1995, now U.S. Pat. No. 5,716,693, the disclosure of which is herein incorporated by reference.
FIELD OF THE INVENTION
The present invention relates generally to sandwich skin constructions. More particularly, the invention relates to high strength, lightweight constructions for vehicle skins.
BACKGROUND OF THE INVENTION
Low density sandwich skin constructions have numerous applications, particularly as non-structural skins for spacecraft, aircraft, cars and other vehicles. Typically, these sandwich skin constructions consist of a lightweight core material wrapped with a thin-gauge outer skin. The interior is usually selected to provide strength and stability to the outer skins. Typical skins are fabricated from metal, plastic, composite, or other materials chosen for desired characteristics. In addition, a variety of core structures and materials have been used, including honeycomb structures, foams and resins.
Prior art sandwich skin constructions derive strength through either a rigid inner core or through a rigid outer skin. In either of these selections, the overall strength to weight ratio of the sandwich skin construction is not maximized. Although sandwich skin constructions are generally lighter than solid skins of equivalent thickness, a trade-off is still required; either the sandwich skin construction is not as strong as it could be, or it is not as light as it could be. However, in some applications of these sandwich skin constructions, such as aircraft and spacecraft skins, the strength to weight ratio is crucial.
Additionally, because of the various layers, sandwich skin constructions tend to react poorly to sheer forces. For example, sheer forces exerted on one skin surface, if not adequately transferred to the core or other surface, cause separation of the skin from the core.
Thus, there is a need for an improved sandwich skin construction that is high strength and lightweight.
SUMMARY OF THE INVENTION
The present invention provides a sandwich skin construction comprising an internal structure of cones coupled side-by-side so that each cone is inverted with respect to each adjacent cone. This internal structure is pressure sealed between two outer skins. Moreover, each individual cone is pressure sealed against the outer skins to localize pressure loss in the event of a skin puncture.
According to an aspect of the invention, the interior of the structure is pressurized with a gas. Preferably, this gas comprises helium to provide a convenient method of detecting leaks in the structure. According to another aspect of the invention, the angle of each cone can be adjusted to oppose the direction of expected external force acting upon the structure in a given application. Thus, the invention can be tailored to provide optimal reaction to stresses in a variety of applications.
In a presently preferred embodiment, each cone of the internal structure contains a smaller inverted minor cone that is attached between an outer skin and the inner larger cone wall. The cones can be added in applications requiring additional structural support.
According to a preferred method of manufacturing the present invention, the cones are first coupled together forming an internal structure. The internal structure is then attached to a first skin. Before a second skin is attached to the internal structure, the partially completed structure is placed in a pressurized environment. The second skin is then attached to the other surface of the internal structure.
Another aspect of the preferred method of manufacturing the present invention comprises adding helium to the pressurized environment before the second skin is welded to the internal structure. Any outgassing of the sandwich structure can thus be more easily detected revealing flaws in the skin surface.
An additional aspect of the preferred method of manufacturing comprises using acid or heat sensitive mylar to transfer an image of the surface to be welded to the second skin as a template for welding. When the second skin is subsequently attached to the sandwich structure, the location of the underlying cones can be more accurately determined.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects achieved by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments that are presently preferred, with the understanding, however, that the invention is not limited to the specific methods and instrumentalities disclosed.
In the drawings:
FIG. 1 illustrates a top view of a preferred embodiment of the present invention with the top skin removed revealing single cones and the weld lines between cones.
FIG. 2 illustrates a cut-away side view of a preferred embodiment of the present invention using single cones.
FIG. 3 illustrates a perspective view of the relationship of the cones within the body of the present invention using single cones.
FIG. 4 illustrates a top view of a preferred embodiment of the present invention with the top skin removed revealing major and minor cones and showing the weld lines between major and minor cones.
FIG. 5 illustrates a cut-away side view of a preferred embodiment of the present invention using major and minor cones.
FIG. 6 illustrates a perspective view of the relationship of the cones within the body of the present invention using major and minor cones.
FIG. 7 illustrates a welding surface of a preferred embodiment of the present invention to be transferred to the second skin.
FIG. 8 illustrates a welding surface of a preferred embodiment of the present invention with major and minor cones to be transferred to the skin.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1-3 depict portions of the sandwich skin construction 10. As shown, the cones 12 are distributed in a side-by-side arrangement with each cone 12 being inverted with respect to each adjacent cone 12. FIG. 3, wherein cone separation distances have been exaggerated for clarity, shows a perspective view of the cone 12 arrangement for a single row of cones 12. As illustrated, cone 12a is oriented with its base down; whereas, the adjacent cone 12b is oriented with its top down. This pattern continues with cone 12c again oriented with its base down and cone 12d oriented with its top down. Other cones 12, shown in FIG. 1, continue to repeat this pattern throughout the structure. As indicated by the weld lines 20, each cone 12 is welded to each adjacent cone 12 forming an internal structure 16. For example, cone 12b is welded to cones 12a and 12c as well as other adjacent cones along the outer surface where the walls of the respective cones 12a, 12b, and 12c meet. Moreover, the entire internal structure is sandwiched between two skins 14a and 14b. The entire sandwich skin construction is sealed along its periphery. Preferably, the skins 14a and 14b are bent over and welded together as shown in FIG. 2.
As can be appreciated from FIG. 3, each cone 12 has a hollow core, a base rim 21 and a top rim 22. Moreover, each cone 12 has an angle that is measure by an arc from the base of the cone to a wall. The base rim 21 and top rim 22 provide a surface area for welding a cone 12 to the skins 14a and 14b. For example, cone 12b is attached to a first skin 14a along its top rim 22b and is attached to a second skin 14b along its base rim 21b. The orientation of the cone 12 (i.e., upright or inverted) determines which rim 21 or 22 is attached to which skin 14a or 14b. As can be appreciated from the FIGS. 1-3, if a given cone 12 has its base rim 21 welded to the first skin 14a and its top rim 22 welded to the second skin 14b, then every adjacent cone 12 would have its base rim 21 welded to the second skin 14b and its top rim 22 welded to the first skin 14a. This weld of base rim 21 and top rim 22 to respective skins 14a and 14b forms a pressurized seal and anchors the skins 14a and 14b to the internal structure 16.
The interior of the sandwich skin construction 10 is pressurized with a gas to provide additional structural support without adding weight. Moreover, a doping gas, preferably helium, is added to the pressurized gas to provide a convenient means of leak detection. By testing the outer skin with a commercially available spectrometer, a leak would be indicated by an unusual level of helium.
The resulting pressure is application specific and is selected to maximize the strength of the sandwich skin construction 10, but will vary according to the application. In general, the pressure should approach the working pressure of the skin material selected. Working pressure of a material is determined empirically by the skin 14a and 14b and cone 12 material, the skin 14a and 14b and cone 12 thickness selected, and the welding technique used to anchor the skins 14a and 14b to the cones 12. For example, if a thin polycarbonate type material with a working pressure of approximately 150 psi is selected for the cones 12 and the skins 14a and 14b, then the internal pressure of the sandwich skin construction should also approach 150 psi. Importantly, the working pressure should be much higher than the atmospheric pressure to maximize the strength of the sandwich skin construction 10, but low enough so that the possibility that the sandwich skin construction could burst from overpressurization is minimized.
According to another aspect of the present invention, because each cone 12 is pressure sealed with respect to the skins 14a and 14b, a rupture in a skin 14a or 14b of the sandwich skin construction 10 will be localized. This ensures that a local rupture will not result in overall loss of pressure and structural integrity in the sandwich skin construction 10.
According to another aspect of the present invention, the angle of the cones 12 is selected to maximize the strength of the sandwich skin construction 10. By appropriately selecting the angle of the cones 12, a force incident upon the surface of the sandwich skin construction 10 would be transferred from one skin (e.g. 14a) to the other skin (e.g. 14b). For example, if the force incident upon the sandwich skin construction 10 is expected to be primarily frictional, the angle of the cone 12 would made more acute. Whereas, if the force incident upon the sandwich skin construction 10 is expected to be primarily compressive, then the angle of the cones 12 would be more normal relative to the skins 14a and 14b. Thus the angle of the cones 12 can be tailored to a specific application. Moreover, the angle of individual cones 12 could be adjusted on a local basis to provide optimized behavior to local stresses.
According to another embodiment of the present invention, when the walls of the cones 12 are thin relative to the height and bursting pressure of the cones 12, additional minor cones 18 are disposed within the cones 12. Adding the additional minor cones 18 would be preferable to increasing the wall thickness of the cones 12 if the overall weight contribution to the sandwich skin construction 10 is thereby minimized. As illustrated in FIGS. 4-6, a minor cone 18 is inverted with respect to each cone 12 and welded along the minor cone base rim 23 at the point where the base of the minor cone 18 contacts the interior of cone 12.
The diameter of the base of the minor cone 18 is selected such that the base of the minor cone 18 contacts a cone 12 at a predetermined point within the interior of a cone 12. In FIG. 6 for example, the minor cones 18 extend more than half-way up into the cones 12. The top of each minor cone 18 extends to the base of the cone 12. The top of each minor cone 18 thus extends to and contacts the first or second skin 14a or 14b.
According to a preferred method of manufacturing the sandwich skin construction 10, the cones 12 are first welded to each other forming an internal structure 16. If minor cones 18 are disposed within the cones 12, then a minor cone 18 is welded within each cone 12 before welding the cones 12 together.
After the internal structure 16 is formed, a first skin 14b is welded to the internal structure 16. The partially completed structure, cones 12 and one skin 14b, is placed in a pressure chamber in which the pressure is changed.
After the desired environmental pressure is achieved, the second skin 14a is welded to the remaining side of the internal structure 16. If minor cones 18 are disposed within the cones 12, then the internal structure 16 must be placed in a pressure chamber and the pressure changed before attaching the first skin 14b. Otherwise, non-pressurized pockets would form in the sandwich skin construction.
According to another aspect of the method of manufacture of the present invention, a mask is fabricated to transfer an image to the surface of skin 14a or 14b to improve the location of welds. Referring now to FIGS. 7 and 8, the weld surface 26 of the internal structure 16 is indicated by shading. FIG. 7 illustrates a mask for an internal structure consisting of cones without minor cones. FIG. 8 shows a mask with minor cones disposed within the cones. A heat source (not show) raises the temperature of the weld surface 26. A heat sensitive mylar is then placed on the weld surface 26, which creates an image of the weld surface 26 on the mylar. The mylar is then placed over the skin 14a which has been treated with a photosensitive coating. This mylar and skin 14a or 14b combination is then exposed to a light source. The light thus transfers the image to the surface of skin 14a.
According to another aspect of the method of manufacture, an acid sensitive mylar may be substituted for the heat sensitive mylar. In that instance, the weld surface 26 is treated with an acid. The acid sensitive mylar is then placed over the weld surface 26. After the acid has etched the image of the weld surface 26 through the mylar, the mylar is then placed over the skin 14a, which has been treated with a photosensitive coating. The skin 14a with the mylar is exposed to a light source, which transfers the image of the weld surface 26 to the skin 14a. Once the image of the weld surface 26 has been transferred to the surface of the skin 14a, using either the heat or acid method, the welding can proceed with much improved accuracy.
The present invention is not limited to the specific presently preferred embodiment described above. For example, the pressurized cells could be cylinders or polyhedrons rather than cones. Accordingly, the scope of protection of the following claims is not limited to the specific embodiments described in detail above, except where they may be explicitly so limited.
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A sandwich skin construction that is comprised of an internal structure comprising a plurality of cones disposed between two outer skins is disclosed. The interior contains a pressurized gas to give the resulting sandwich skin construction added strength over a similarly constructed non-pressurized structure of the same material with an equivalent mass. Various attributes of the cones can be adjusted, for example, size and angle, to optimize the performance of the sandwich skin construction to a variety of external stresses. Moreover, a method is provided for manufacturing the sandwich skin construction. The structure can be placed in a pressurized environment before attaching the outer skins.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the invention relate to digital triggering of signals.
2. Discussion of the Background
A digital oscilloscope can now present analog signals very accurately on a display device after sampling the analog signal over time and digitize the sampled values of the analog signal at the individual sampling times by means of analog-digital conversion.
The triggering of the digitized signals to be presented on the display device of the digital oscilloscope is now also realized in digital manner. In the document DE 39 36 932 A1, an analog signal converted into the digital data format is compared in a comparator with reference to overshooting or undershooting a threshold value stored in a register. The first overshooting or undershooting of the threshold value by one of the sampled values of the analog signal to be presented is identified by the triggering system as a triggering time and leads to a triggering impulse, which is used in the display device for recording the signals to be presented synchronously with the triggering impulse.
The digital triggering of DE 39 36 932 A1 implements only a static triggering on the basis of a single signal-level comparison with one threshold value. The fact that a dynamic triggering on the basis of a time-dependent signal feature—for example, a triggering on the basis of a signal slope of the signal, a duration of a signal impulse or a time delay of a signal impulse by comparison with a reference impulse—is not yet possible using a digital triggering system of this kind is disadvantageous.
SUMMARY OF THE INVENTION
In accordance with various embodiments of the invention, a system and method are provided for digital triggering of signals, in which time-dependent signal features of the signal to be presented on the digital oscilloscope can be used as a triggering condition for a digital triggering, and of providing a corresponding digital oscilloscope.
Embodiments of the invention include a method for digital triggering, a system for digital triggering, and a digital oscilloscope.
According to an embodiment of the invention, a digital triggering of this kind, instead of one triggering event based upon one level comparison with one threshold value, as in the conventional art, two triggering events based upon two level comparisons each with one threshold value are identified, and the time difference between the two triggering events is used as the triggering condition for a dynamic triggering. The digital triggering is implemented in the case of an overshooting and also in the case of an undershooting of a threshold value by the time difference between the two identified triggering events. In this manner, a digital triggering is possible alternatively with a positive or negative signal slopes with a signal impulse up to a maximum impulse duration or from a minimum impulse duration or with a signal-impulse delay up to a maximum impulse delay or from a minimum impulse delay.
According to another embodiment of the invention, the time difference between the first and second triggering event is determined via the number of sampling times of the signals to be triggered between the two triggering events. On the one hand, as a result of the time discretization, a first inaccuracy in the precise determination of the first and second triggering events arises in the timing of the exact overshooting or undershooting of the threshold value by the time-discretized signal—reference signal—used in each case for the triggering; and, on the other hand, a second inaccuracy arises a result of a possible synchronicity error between the respectively-determined first or second triqgeritng event and the sampling raster of the signals to be presented on the digital oscilloscope.
The first inaccuracy, resulting from the imprecise determination of the first and second triggering events, is resolved by determining the levels of intermediate points between the last preceding sampling time and the next following sampling time of the reference signal(s) before and respectively after the first and second triggering event by means of interpolation, and by comparing the determined levels of the intermediate points with reference to overshooting or undershooting the threshold value(s). In this manner, the times of the first and second triggering events can be determined significantly more precisely.
The second inaccuracy resulting from the synchronicity error means that the occurrence of the triggering condition can be either unambiguously identified or unambiguously not identified or neither unambiguously identified nor unambiguously not identified. The triggering condition is unambiguously identified or unambiguously not identified, if the determined number of sampling times between the first and second triggering event either overshoots an upper threshold value or undershoots a lower threshold value. If the determined number of sampling times is disposed between the first and second triggering event between this upper and lower threshold value, then the occurrence of the triggering condition can neither be unambiguously identified nor unambiguously not identified. In this case, the display of the signals to be presented on the digital oscilloscope cannot be started via a triggering impulse and must be postponed until an unambiguous identification of the triggering condition.
In this approach, by way of an example, the individual sampled values of the signals to be presented on the digital oscilloscope must be buffered in a FIFO memory and the unambiguous occurrence or the unambiguous non-occurrence of the triggering condition are determined in a further, subsequent determination of the exact times of the first and second triggering events, and therefore of the exact time difference between the first and second triggering event if the presence of the triggering condition is identified in the fine analysis, the sampled values of the signals to be recorded, which have been buffered in the FIFO memory, are retrospectively presented on the display of the digital oscilloscope via a triggering impulse.
It should also be mentioned that, in the case of an overshooting of a threshold value, the upper and lower threshold values for the number of sampling times between the first and second triggering event for the unambiguous identification or unambiguous non-identification of the triggering condition adopt a different value—first lower and first upper threshold value—by contrast with the case of an undershooting of a threshold value—second lower and second upper threshold value. Additionally, the upper and lower threshold value for a threshold-value comparison of the time difference between the first and second triggering time with the “>=” or respectively “<=” inequality condition provides different values by contrast with a threshold-value comparison of the time difference between the first and second triggering time with the “>” or respectively “<” inequality condition.
According to yet another exemplary embodiment of the invention a method and the system are provided for the digital triggering of signals on the basis of two triggering events separated by a time difference, and the digital oscilloscope are explained in greater detail below with reference to the drawings.
Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention is also capable of other and different embodiments, and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
Various exemplary embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which:
FIG. 1 shows a block-circuit diagram of a conventional digital oscilloscope;
FIG. 2 shows a block-circuit diagram of a system for digital triggering of signals on the basis of two triggering events separated by a time difference, according to an exemplary embodiment of the present invention;
FIG. 3 shows a block-circuit diagram of a sub-system for fine analysis of triggering conditions, according to an exemplary embodiment of the present invention;
FIG. 4 shows a block-circuit diagram of a digital oscilloscope according to an exemplary embodiment of the present invention;
FIGS. 5A , 5 B, 5 C, 5 D, 5 E, 5 F show time characteristics of various triggering conditions, according to various embodiments of the present invention;
FIG. 6 shows a flow chart of a method for digital triggering of signals based on two triggering events separated by a time difference according to an exemplary embodiment of the present invention; and
FIG. 7 shows a flow chart of a sub-routine for fine analysis of triggering conditions, according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before describing the method and system for digital triggering of signals on the basis of two triggering events separated by a time difference with reference to FIGS. 2 to 7 and the associated digital oscilloscope, the digital oscilloscope according to the prior art will first be presented with reference to FIG. 1 . This is necessary for the further understanding of the invention.
Using a pre-amplifier 1 , which provides a variable amplification factor, the digital oscilloscope according to the prior art shown in FIG. 1 matches the level of the amplitudes of the measured signals present at its input with the measurement range of the display device 4 . After the level matching, the pre-amplified, analog measured signals are supplied to an analog-digital converter 2 for conversion into a corresponding digital data format. The digitized measured signal is checked with reference to a triggering condition by a digital triggering system 3 . If this triggering condition is identified, a triggering impulse for triggering the digital oscilloscope is generated at the output of the digital triggering system 3 . The sampled values of the digitized measured signals, which are registered simultaneously with the triggering impulse or directly following the triggering impulse in time, are presented on the screen of the display unit 4 of the digital oscilloscope.
The system for digital triggering of signals on the basis of two triggering events separated by a time difference shown in FIG. 2 provides a first comparator 5 for the identification of a first triggering event. A first reference signal S i selected from all of the signals S to be presented on the digital oscilloscope is supplied to a first input 6 of the first comparator 5 . A threshold signal SW i , with which the first reference signal S i is compared in the first comparator 5 with reference to overshooting or undershooting, is disposed at the second input 7 of the comparator 5 . The comparison with reference to overshooting or undershooting in the first comparator 5 is determined by the signal disposed at the third input 8 , which indicates a comparison with regard to positive or negative slope. The output 9 of the first comparator 5 is activated in the case of an overshooting or undershooting of the threshold signal Sw i by the first reference signal S i .
In a similar manner, a second comparator 10 is provided for the identification of a second triggering event following the first triggering event. Either the first reference signal S i supplied to the first input 6 of the first comparator 5 or a second reference signal S j , which provides a time delay by comparison with the first reference signal S i , is disposed at the first input 11 of the second comparator 10 . The threshold signal present at the second input 12 of the second comparator 10 is either the threshold signal SW i also provided at the second input 7 of the first comparator 5 or a threshold signal SW j , which differs from this threshold signal SW i . The signal provided at the third input 13 of the second comparator 10 determines whether the threshold-value comparison in the second comparator 10 is to be implemented between the first reference signal S i or respectively the second reference signal S j and one of the two threshold signals SW i or SW j in the case of a positive or negative slope. The output 14 of the second comparator 10 is activated by the first or second reference signal S i or respectively S j in the case of an overshooting or undershooting of the threshold signal SW i or respectively SW j .
With the first comparator 5 and the second comparator 10 , it is therefore possible, on the basis of two triggering events separated by a time difference—first and second triggering event—, to adjust and to identify the following substantial triggering conditions with reference to the first and respectively second reference signal S i and respectively S j :
identification of a positive or negative slope with a given minimum or maximum gradient in a reference signal S i ( FIG. 5A , 5 B); identification of a digital reference-signal impulse S i or an analog reference signal S i with a given minimum or maximum length ( FIG. 5C , 5 D); and identification of a signal delay with a given minimum or maximum delay at the start or at the end of the signal between a first reference signal S i and a second reference signal S j with a time delay relative to the first reference signal S i ( FIG. 5E , 5 F).
The output 9 of the first comparator 5 is supplied to the start-input 15 , and the output 14 of the second comparator 10 is supplied to the stop-input 16 of the counter 17 . The sampling frequency Clk of the analog-digital converter 2 of the digital oscilloscope is disposed at a third input 18 of the counter 17 . The counter 17 counts the number n sampling times of the signals S to be presented on the digital oscilloscope between the first triggering event (output signal of the first comparator 5 disposed at the start-input 15 of the counter 17 ) and the second triggering event (output signal of the second comparator 10 disposed at the stop-input 16 of the counter 17 ).
The sampling times n counted by the counter 17 between the first and second triggering event at the output 19 of the counter 17 are supplied on the one hand to a first input 20 of a third comparator 21 , and on the other hand, to a first input 22 of a fourth comparator 23 . The second input 24 of the third comparator 21 receives the upper threshold value Gw o stored in a register 25 . The second input 25 of the fourth comparator 23 is supplied with the lower threshold value Gw u stored in a register 26 .
The first comparator 21 compares the number n, registered in the counter 17 , of sampling times between the first and second triggering event with the upper threshold value GW o and activates the first; output 26 if the number n of sampling times is greater than or equal to the upper threshold value GW o , and activates the second output 27 , if the number n of sampling times is less than the upper threshold value GW o . The fourth comparator 23 compares the number n, determined in the counter 17 , of sampling times between the first and second triggering event with the lower threshold value GW u and activates the first output 28 , if the number n of sampling times is greater than or equal to the lower threshold value GW u , and activates the second output 29 , if the number n of sampling times is less than the lower threshold value GW u .
The definition of the registers 25 and 27 with upper and lower threshold values GW o and GW u , for example, first and second upper threshold values GW o1 , GW o2 and first and second lower threshold values GW u1 , GW u2 , is implemented by a superordinate process-control unit, not illustrated here, of the system for digital triggering of signals on the basis of two triggering events separated by a time difference. In this context, it should be stated that the occurrence of the triggering condition or the non-occurrence of the triggering condition cannot be unambiguously inferred from the number n, determined by the counter 17 , of sampling times between the first and second triggering event; in fact, for given values of the number n of sampling times between the first and second triggering event, either the unambiguous occurrence or the unambiguous non-occurrence of the triggering condition must be determined retrospectively by a separate fine analysis.
This indeterminacy in the identification of the triggering conditions results from the inaccuracy n the exact determination of the first and second triggering events synchronicity errors between the sampling raster and the precise first or respectively second triggering event, the maximum value of which can be up to one sampling time, and from a lack of precision in the threshold-value comparison, which is determined by the use of “>=” or “<=” instead of a “>” or “<” as comparison operators. For these reasons, the upper and lower threshold value can differ by a maximum factor of three, and can accordingly determine up to two intervening values for the number n of sampling times between the first and second triggering event, for which neither an identification of the triggering condition is unambiguously present nor unambiguously not present. A superordinate process-control unit, which is not illustrated, of the system for digital triggering accordingly defines the registers 25 and 26 in agreement with the comparison operator—“>=”, “<=”, “>” or “<” selected in the comparison of the time difference Δt between the first and second triggering event with the time threshold value SW t with respectively appropriate upper and lower threshold values GW o and GW u .
The signal at the first output 26 of the third comparator 21 —n≧GW 0 —and the signal at the first output 28 of the second comparator 23 —n≦GW u —are each supplied to one of the two inputs 31 and 32 of a multiplexer 30 . Dependent upon a signal disposed at a third input 33 of the multiplexer 30 , which indicates an overshooting or undershooting of a specified time threshold SW t by the time difference Δt between the first and second triggering event, the multiplexer 30 connects either the activated signal of the first output 26 of the third comparator—n≧GW o —in the case of an overshooting of the time threshold SW t —or the activated signal of the first output 28 of the fourth comparator 23 —n≦GW u —in the case of an undershooting of the time threshold SW t —through to the output 34 of the multiplexer 30 , which acts as a triggering impulse s TR for triggering the signals S to be presented on the digital oscilloscope.
The third and fourth comparator 21 and 23 , the associated registers 25 and 26 storing the upper and lower threshold value GW o and GW u and the multiplexer 30 therefore provide a unit 54 for the identification of triggering conditions.
The activated signal at the second output 27 of the third comparator 21 —n<GW o —and the activated signal at the second output 29 of the fourth comparator 23 —n>GW u —are supplied respectively to one of the two inputs 35 and 36 of an AND gate 37 and generate the signal FA for fine analysis of the triggering condition at the output 38 . In this fine analysis, the sampled values of the reference signal(s) S i and respectively S j are evaluated in order to achieve a more-accurate determination of the first and second triggering events and therefore of the time difference Δt between the first and second triggering events. A subsequent threshold comparison of the precisely-determined time difference Δt between the first and second triggering event with a time threshold SW t allows an unambiguous identification or non-identification of the triggering condition.
In the sub-system for the fine analysis of triggering conditions according to FIG. 3 , the sampled values of the signals S to be presented on the digital oscilloscope are supplied to several delay elements 39 1 , 39 2 , . . . , 39 N connected in series, in which they are delayed respectively by the sampling time T i of the analog-digital converter 2 . The signals disposed at the individual outputs of the individual delay elements 39 1 , 39 2 , . . . , 39 N , which are each delayed relative to one another by a different number of sampling cycles T i and therefore represent the sampled values of the signals S to be presented on the digital oscilloscope, which have been buffered since the identification of the first triggering event, are supplied to the input of a switch 40 and passed on, in the case of an activated signal FA, for a fine analysis of the triggering condition to a first-in-first-out memory (FIFO memory) 41 , in which they are buffered.
The last sampled value preceding the first identified triggering event and the next sampled value following the first identified triggering event, S in and S in+1 respectively, of the first reference signal S i , and the last sampled value preceding the second identified triggering event and the next sampled value following the second identified triggering event, S im and S im+1 or respectively S jm and S jm+1 of the first or respectively second reference signal S i and respectively S j are read out from the FIFO memory 41 , by means of a process-control unit, which is not illustrated, of the system for digital triggering, and supplied to a unit 42 for determining the first and second intermediate points Z 1 and Z 2 between the sampled values close to the threshold value S in and S in+1 together with S im and S im+1 and respectively S jm and S jm+1 of the first and respectively second reference signal S i and respectively S j . The levels of intermediate points Z 1 and Z 2 are calculated in the unit 42 via a given interpolation method, which will not be explained in greater detail in present context, and supplied to a fifth and six comparator 43 and 44 for a more precise determination of the first and second triggering event.
A threshold-value comparison of the first intermediate points Z 1 with a threshold value SW i is implemented in the fifth comparator 43 ; while a threshold-value comparison of the second intermediate points Z 2 is implemented in the sixth comparator 44 with the same threshold value S i in the case of an identification of a signal impulse with a given impulse length or with a given signal delay; or with another threshold value SW j in the case of an identification of a signal slope.
The outputs Z 1 >SW i and Z 1 <SW i corresponding to the number of first intermediate points Z 1 provided respectively for an overshooting and an undershooting of the threshold value SW i , which are activated respectively in the presence of the relevant comparison condition, are evaluated in a subsequent, first evaluation-logic unit 45 for the determination of the more-precise timing point t TR1 of the first triggering event. Similarly, the outputs Z 2 >SW i and Z 1 <SW i or respectively Z 2 <SW i corresponding to the number of second intermediate points Z 2 provided respectively for an overshooting and an undershooting of the threshold value SW i and respectively SW j , which are activated respectively in the presence of the relevant comparison condition, are evaluated in a subsequent second evaluation-logic unit 46 for the determination of the more-precise timing point t TR2 of the second triggering event.
A subsequent subtraction element 47 calculates the time difference Δt between the first and second triggering event from the difference between the timing point t TR2 of the second triggering event and the timing point t TR1 of the first triggering event. This time difference Δt is supplied to a first input 49 of a subsequent seventh comparator 48 and compared with reference to overshooting or undershooting a time-threshold value SW t present at the second input 50 . For this purpose, the signal present at the third input 33 of the multiplexer 30 is supplied to a third input 51 of the seventh comparator 48 , which indicates a comparison with reference to an overshooting or undershooting of the time threshold SW t . In the event of the comparison condition, a triggering impulse s TR ′, which delays the sampled values of the signals S to be displayed on the digital oscilloscope, which have been buffered since the occurrence of the first triggering event, in the FIFO memory 41 , is activated at the output 52 of the seventh comparator 48 and passes on the evaluation time of the fine analysis instead of the currently pre-amplified and sampled signals S to the recording device 4 of the digital oscilloscope.
The unit 42 for determining the first and second intermediate points Z 1 and Z 2 between sampled points S in , S in+1 , S im , and S im+1 close to the threshold, the fifth and sixth comparators 43 and 44 , the first and second evaluation-logic units 45 and 46 , the subtraction element 47 and the seventh comparator provide a unit 55 for fine identification of triggering conditions.
FIG. 4 shows the block-circuit diagram of the digital oscilloscope together with the functional units already presented in FIG. 3 with reference to the system for fine analysis of the triggering conditions. The description of these functional units is therefore not repeated at this point.
FIG. 6 presents the method for digital triggering of signals on the basis of two triggering events separated by a time difference.
In the first procedural stage S 10 , the first and second triggering events are determined by means of a first and second comparator 5 and 10 from a first reference signal Si selected from all of the signals S to be presented on the digital oscilloscope or from an additionally-selected second reference signal S j by means of a threshold-value comparison with a first threshold-value signal SW i , or respectively, additionally, with a second threshold-value signal SW j , with an accuracy corresponding to the level of the sampling periods of the signals S to be presented on the digital oscilloscope.
In procedural stage S 20 , using the first and second triggering event determined in procedural stage S 10 , the number ri of sampling times between the first and the second triggering event of the signals S to be presented on the digital oscilloscope are counted in a counter 17 .
In procedural stage S 30 , the number n, determined in procedural stage S 20 , of sampling times between the first and second triggering event is compared with reference to overshooting or undershooting an upper and lower threshold value GW o and GW u in order to achieve an unambiguous identification or an unambiguous non-identification of the triggering condition. In this context, the upper and lower threshold values GW o and GW u corresponding to the comparison operators “>=”, “<=”, “>” or “<”, which have been selected by the user or by the system for the threshold-value comparison of the time difference Δt between the first and second triggering time, are selected by a superordinate process-control unit of the system for digital triggering.
If the threshold-value comparison of the number n of sampling times between the first and second triggering event provides an unambiguous identification of the triggering condition in procedural stage S 40 , a triggering impulse s TR for the triggering of the signals S to be presented on the digital oscilloscope is generated in the next procedural stage S 50 .
If the threshold-value comparison in procedural stage S 60 also fails to provide an unambiguous non-identification of the triggering condition, a fine analysis of the triggering condition is implemented within the framework of a sub-routine S 70 , the purpose of which is to provide an unambiguous retrospective identification or an unambiguous retrospective non-identification of the triggering condition.
The sub-routine for fine analysis of the triggering condition, which is executed within the method for digital triggering of signals on the basis of two triggering events separated by a time difference shown in FIG. 6 as procedural stage S 70 , is described in detail in FIG. 7 .
The first procedural stage S 100 of the sub-routine for fine analysis of the triggering condition illustrated in FIG. 7 provides the buffering of all sampled values of the signals S to be presented on the digital oscilloscope in a first-in-first-out memory 41 from the time of the identification of the first triggering event.
In the subsequent procedural stage S 110 , the levels of the first intermediate point Z 1 , which are disposed between the last sampling time preceding the first triggering event and the next sampling time following the first triggering event of the first reference signal S i , and the levels of the second intermediate point Z 2 , which are disposed between the last sampling Lime preceding the second triggering event and the next sampling time following second triggering event of the first or second reference signal S i or S j , are determined by means of an interpolation method.
In procedural stage S 120 , the timing points t TR1 and t TR2 of the first and second triggering event are determined in a fifth and sixth comparator 43 and 44 and a first and second evaluation-logic unit 45 and 46 by comparing the first and second intermediate values Z 1 and Z 2 with a threshold-value signal SW i or with an additional threshold-value signal SW j .
In procedural stage S 130 the time difference Δt between the first and second triggering event is determined in a subtraction element 47 on the basis of the determined timing points t TR1 and t TR2 of the first and second triggering event and, following this, compared in a seventh comparator 48 with reference to overshooting or undershooting a time-threshold value SW t in order to achieve an unambiguous identification of the triggering condition or an unambiguous non-identification of the triggering condition.
If an unambiguous identification of the triggering condition is present in procedural stage S 140 as a result of the threshold-value comparison in procedural stage S 130 , a triggering impulse s TR ′ for triggering the sampling values of the signals S to be presented on the digital oscilloscope, which have been buffered in the FIFO memory 41 since the identification of the first triggering event, is generated in the final procedural stage S 150 .
The invention is not restricted to the embodiment illustrated. In particular, other numerical methods for the determination of more-precise timing points of the first and second triggering event, especially delay-time-optimised methods, are also covered by the invention.
While the invention has been described in connection with a number of embodiments and implementations, the invention is not so limited but covers various obvious modifications and equivalent arrangements, which fall within the purview of the appended claims. Although features of the invention are expressed in certain combinations among the claims, it is contemplated that these features can be arranged in any combination and order.
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An approach is provided for digital triggering a recording of one or several signals sampled at individual sampling instants on a digital oscilloscope. The triggering is carried out when the interval between two recurrent triggering events is less or greater than a time threshold value.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to processes for manufacturing propynol from acetylene and formaldehyde.
2. Discussion of the Background
Propynol is used for synthesizing polyacetylenes and other natural substances. It is also used as a corrosion protection agent in the electroplating industry.
Propynol is produced in small amounts as a by-product in the production of 1,4-butynediol from formaldehyde and acetylene.
In the known processes for producing propynol, the starting materials are also formaldehyde and acetylene. In these processes the reaction of propynol with formaldehyde to form 1,4-butynediol is suppressed by the use of special reaction conditions. For example, German Pat. No. 1,174,765 discloses the use of N-methylpyrrolidone, which is a good solvent for acetylene and therefore enables a high acetylene concentration.
The reaction of acetylene and formaldehyde in the presence of copper acetylide leads principally to propynol, according to German Pat. No. 1,174,765. Separation out of the high boiling solvent however is technically complex and cost-intensive.
According to German Pat. No. 1,284,964, acetylene and formaldehyde can be reacted, with the aid of copper acetylide on a support, to form 1,4-butynediol and propynol. The two products are formed in comparable amounts. Formaldehyde dimethylacetal is noted as a solvent, but the preferred solvent is said to be butyrolactone. The dissolution is carried out under cooling, but requires increasingly high pressures, which represent a major safety risk.
The underlying problem in the production of propynol is the absence of a process permitting the production of propynol from acetylene and formaldehyde at decreased cost and with increased process safety.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a process for the preparation of propynol from acetylene and formaldehyde.
It is another object of this invention to provide a process for the economical production of propynol from acetylene and formaldehyde.
It is another object of this invention to provide a safe process for the production of propynol from acetylene and formaldehyde.
The inventors have now discovered a process which satisfies all of the above objects of this invention and other objects which will become apparent from the description of the invention given hereinbelow. In the present process for manufacturing propynol from acetylene and formaldehyde, dimethoxymethane and a copper acetylide catalyst are used. The acetylene is dissolved in the dimethoxymethane under strong cooling, either at normal pressure or under a slight gauge pressure, and this cooled solution is then introduced into the reactor.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of this invention and many of its attendant advantages will be readily obtained as the same becomes better understood by reference to the following description when considered in connection with the accompanying drawing, wherein:
FIG. 1 provides a schematic illustration of an installation in which the present process can be performed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the present invention acetylene is dissolved in dimethoxymethane under strong cooling, at normal pressure or slight gauge pressure, and the cooled solution is fed to the reactor.
The dissolution of acetylene in dimethoxymethane can be carried out, e.g., in an absorber, in which temperatures of -10° to -50° C. are maintained, preferably -15° to -40° C., and pressures of from 1 to 5 bar, preferably 1.5 to 4 bar, are used.
According to the invention the acetylene can be supplied to the reaction at low pressure. The method is therefore simple and safe in operation. Further, it enables large scale-up with decreased hazard.
General Description of the Method
As illustrated in FIG. 1, in the present invention as it is illustrated in the figure acetylene is passed through line 1 into absorber 2. A vessel with stirrer may be used as the absorber, or an absorption column filled with packing may be used. The acetylene can be fed concurrently with or countercurrently to the solvent.
The solvent, dimethoxymethane, which may also contain up to 20% (vol.) methanol, but preferably contains <10% (vol.) methanol, is cooled in a heat exchanger 3 and passed into the absorber via line 4.
A solution saturated with acetylene (depending on pressure and temperature) is pumped into the reactor 6 by pump 5. For improved energy utilization, heat exchange is carried out in a heat exchanger 7 operating between the acetylene solution and the dimethoxymethane being recycled. The required amount of formaldehyde is fed through line 8. Aqueous formaldehyde solutions with formaldehyde contents of 30 to 80% are used. Also, formaldehyde solutions in dimethoxymethane may be used.
The reactor is filled with a catalyst packing (fixed bed). The catalyst is copper acetylide, which may be in the forms described in, e.g., German Pat. Nos. 1,235,295 and 1,013,279. The reactor is equipped with cooling and heating means 9. The reactor is filled hydraulically. The reaction pressure is maintained at 10 to 200 bar by a pressure regulation device 10. The reaction temperature is 85° to 150° C.
The reaction mixture, which essentially is comprised of dimethoxymethane, methanol, propynol, 1,4-butynediol, formaldehyde, and water, is passed through line 11 into the dimethoxymethane recovery column 12. The dimethoxymethane/methanol mixture which is separated out is recycled to the process. The mixture of propynol, 1,4-butynediol, formaldehyde, and water is passed to the standard refining steps, via line 13.
Other features of this invention will become apparent in the course of the following descriptions of exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof.
Example
Catalyst (comprised of 1/8 inch pellets) (500 ml) was charged into a tubular reactor (length 1000 mm, inner diameter 23 mm) equipped with temperature and pressure measuring devices and a jacket for heating and cooling. The catalyst was prepared as described in German Pat. No. 1,235,295, and contained 35% Cu, 3% Bi 2 O 3 , and 43% magnesium silicate.
Acetylene and dimethoxymethane were introduced into a stirred autoclave at -16° C. and 2.1 bar, to produce a saturated solution of acetylene in dimethoxymethane.
This saturated solution was continuously fed to the reactor by a piston pump, at 444 g/hr. 56 g/hr of a 50% aqueous formaldehyde solution was added in measured amounts to the said saturated solution which was heated to the reaction temperature of 115° C. A second piston pump was used for the formaldehyde addition.
The heat of reaction which was liberated was removed by cooling. The reaction pressure was 20 bar. The mean residence time of the reaction mixture in the reactor was 0.7 hr. The material withdrawn from the reactor had the following composition:
Dimethoxymethane: 75.1%
Methanol: 6.9%
1,4-Butynediol: 6.3%
Water: 6.3%
Propynol: 5.1%
Formaldehyde: 0.3%
From 500 g/hr reaction mixture, dimethoxymethane and methanol were separated out and recovered. The remainder was processed by distillation according to German Pat. No. 1,002,324. The propynol product was >99% pure.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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A process for manufacturing propynol from formaldehyde and acetylene is disclosed. In this process the acetylene is first dissolved in a dimethoxymethane solvent under strong cooling and at slight gauge pressure. The cool acetylene-containing solution is then fed to a reactor charged with formaldehyde and a catalyst.
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BACKGROUND OF THE INVENTION
Heretofore speed bumps have been installed on roads particularly in congested areas where it is desired that the vehicles travel at a relatively slow speed. These speed bumps are often installed in large parking lots, school zone, apartment building complexes, etc.
One problem with such speed bumps is that they are normally constructed of asphalt and project above the road surface approximately six to eight inches. In order to pass over these speed bumps without imparting substantial jar to the vehicle, the speed of the vehicle must be reduced to approximately five miles an hour in some instances. Even when the speed of the vehicle has been reduced, a substantial jar is often imparted to the vehicle and in some cases the speed bump strikes the frame of the vehicle.
In order to overcome these undesirable disadvantages attempts have been made to produce retractible safety speed bumps such as disclosed in U.S. Pat. No. 4,012,157. Such a speed bump is provided to be nested into a recess when not in use. Another removable speed bump is disclosed in U.S. Pat. No. 1,688,409. In this particular device the speed bump is pivoted out of the path of the vehicles when not in use.
SUMMARY OF THE INVENTION
The speed bump constructed in accordance to the present invention is provided for imparting a controlled bump to a vehicle as the tires of the vehicle passes thereover. The degree of jar imparted to the vehicle as the vehicle passes thereover depends on the speed of the vehicle.
The speed bump constructed in accordance with the present invention includes an elongated flexible housing which has a length sufficient to extend across a portion of the road for covering the path traveled by the vehicles. An elongated sealed chamber is carried in the housing and fluid is provided in the sealed chamber.
The elongated flexible housing is secured by any suitable means such as spikes passing through flanges provided thereon into the road bed. The elongated housing projects vertically above the road and is compressed by the tire of the vehicle as the tire passes thereover displacing the fluid under the tire within the chamber. Various means are provided for restricting displacement of the fluid within the chamber at a controlled rate so that if the vehicle is traveling at a very slow speed the bump is compressed minimizing the jar wherein if the vehicle is traveling at a higher undesirable speed there is insufficient time for the bump to collapse thereby imparting a substantial jar to the vehicle.
In one particular embodiment the means for retarding the displacement of the fluid within the elongated chamber includes an elongated plate which divides the housing into an upper and lower chamber. The fluid is normally contained in the lower chamber and the plate has passages provided therein which allow the fluid to flow through the passages into on upper chamber responsive to the pressure of the tire bearing down on a portion of the housing. The number and the size of the holes in the plate control the retarding force imparted by the fluid.
In another embodimemt a conduit extends from one end of the elongated flexible housing to the bottom of a vertically extending cylinder. Provided within the cylinder is a displacable piston. As the tire strikes the flexible housing, the piston is raised producing a retarding force.
In still another embodiment the retarding force is produced by the flexibility of a cylinder in which the fluid is carried.
Accordingly it is an important object of the present invention to provide a speed bump wherein the jolt imparted to the vehicle that passes thereover varies according to the speed that the vehicle is traveling.
Still another important object of the present invention is to provide a speed bump which includes an elongated flexible housing compressible to minimize the jolt imparted to a vehicle traveling at the desired speed as it passes thereover.
Other objects and advantages of this invention will become more apparent from reading the following detailed description and appended claims taken in conjunction with the accompanying drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, with parts broken away, illustrating a speed bump constructed in accordance with the present invention.
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is a longitudinal sectional view illustrating a tire of a vehicle compressing the elongated tube as it passes thereover.
FIG. 4 is a side elevational view of a modified form of the invention.
FIG. 5 is a perspective view, with parts broken away for purposes of clarity, illustrating still another modified form of the invention.
FIG. 6 is a sectional view taken along line 6--6 of FIG. 5.
FIG. 7 is a side view of still another modified form of the invention.
FIG. 8 is a side elevational view of still another modified form of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring in more detail to FIG. 1 of the drawings, there is illustrated a speed bump for use on a road 10 for imparting a controlled impact to a vehicle as the tires of the vehicle pass thereover. The bump includes an elongated flexible housing 12 constructed of any suitable hard rubber material and has a substantially triangular upper portion with a rounded top 14 and a horizontal base 16 producing an elongated sealed chamber. Opposed flanges 18 and 20 are integral with the inner walls and have grooves provided therein for receiving downwardly turned flange portions 22 and 24 of an elongated horizontally extending plate 26. The plate has longitudinally spaced holes 28 provided therein. The plate divides the interior of housing into a lower chamber 30 and an upper chamber 32. Communication between the lower chamber 30 and the upper chamber 32 is through the openings 28 provided in the plate 26.
Outwardly extending flanges 34 and 36 are provided adjacent the bottom of the housing through which fastening devices such as bolts 38 can pass for securing the bump to the road.
In operation as a vehicle passes over the bump, the tire 40 rolls over the top portion 14 of the bump, depressing the bump. The increased pressure build-up on the fluid directly below the tire causes the fluid 42 to be forced upward through the openings 28 from the lower chamber 30 into the upper chamber 32. The number of openings 28 and the size of the openings control the retarding force imparted by the fluid.
As a result if the automobile is travelling at the desired rate of speed, say five miles per hour, there will be sufficient time for the bump to be compressed. However, if the vehicle is travelling at an excessive rate of speed, for the particular road then upon striking the bump, the bump will not be compressed entirely and a very unpleasant and sudden shock will be imparted to the vehicle. In other words the bump produces a shock having an intensity which varies according to the speed of the vehicle.
In FIG. 4 there is illustrated a modified form of the invention wherein the elongated housing 44 constructed in the same manner as the housing shown in FIGS. 1 and 2 is provided for extending across the path of travel of vehicles on the road. The only difference is that there is a single inner chamber 46 that is filled with fluid 48. Adjacent the right end of the chamber 46 is a conduit 50 that extends to the bottom of the vertically extending cylinder 52. Positioned in the cylinder 52 is a weighted piston 54. As the tire of the vehicle passes over the housing 44 it compresses the housing forcing the fluid through conduit 50 causing the piston 54 to be raised. The retarding force on the fluid can be varied by varying the weight of the piston 54.
In FIG. 5 there is illustrated still another modified form of the invention. An elongated flexible housing 56 is constructed in the same manner as the housing 12 with the exception that it is hollow throughout. Positioned within the hollow chamber are a plurality of longitudinally spaced cylinders 58 that are partially filled with fluid 60. By using a plurality of cylinders instead of a single chamber, the bump can be positioned on an inclined road surface without the fluid flowing completely to the lower end thereof.
As a vehicle's tire passes over the bump 56 it causes the housing and the cylinder 58 positioned directly therebelow to be compressed. The cylinder 58 may be constructed of any suitable flexible material so that when pressure is imparted by the tire over one point it will deform within the housing 56. Any suitable fluid can be utilized within the cylinders as long as it does not freeze. It should have a freezing point much lower than the lowest temperature that would be incurred during wintertime in the area.
The degree of shock imparted by the speed bump can be varied by varying the ratio of fluid and water within the cylinder 58.
For example if a substantial amount of water is provided in the cylinder, the shock is less severe than when the cylinder is completely full with fluid. When the cylinder is completely full of fluid, the fluid causes the walls of the cylinder to expand as the tire rolls over the bump. Whereas when there is a substantial amount of air in the cylinder the air within the cylinder is compressed and the flexibility of the wall of the cylinder 58 has less effect.
In FIG. 7 there is illustrated still another modified form of the invention wherein a mechanical device is used for providing a bump to tires. The mechanical device includes a pair of bearing blocks 62 which are spaced across the road. The bearing blocks are recessed down below the road bed so that a horizontally extending rod member 64 is located substantially flush with the upper surface of the road bed. Extending outwardly from the rod 64 are braces 66 which have another rod 68 secured to the outer ends thereof.
The rod-like member 64 extends laterally beyond the bearing post 62 and has a radially extending arm 70 fixed to the end thereof. The arm extends vertically downwardly whereas the braces 66 extend vertically upwardly. Adjustably fixed to the lower end of the arm 70 is a weight 72 which is greater than the weight of the rod 68 and the braces 66 so that the weight maintains the braces 66 extending vertically upwardly.
Depending on the direction that the car strikes the upper rail 68 the rail will pivot from a vertical position to a horizontal position. If the car strikes the rail at a slow speed the retaining force imparted by the counter weight 72 is overcome at a slower rate, minimizing the shock imparted by the rail 68 striking the tire. However, if the vehicle strikes at an excessive rate of speed a sudden jar will be imparted through the tires to the vehicle as a result of the retarding force imparted by the counter weight 72.
In FIG. 8 of the drawings there is illustrated still another modified form of the invention wherein instead of the rail 68 being able to pivot in either direction for imparting a controlled jar to cars traveling in both directions on a road it can pivot in only one direction. In some instances it is desired to use the bump to act as more or less a barrier against travel in one direction while permitting free travel in the other direction. For example on access roads to superhighways which are normally one way, if the vehicle were traveling as shown in FIG. 8 from left to right the weight would strike a vertical wall 74 of the recess chamber 76. As a result the rail 68 would remain in the vertical position shown. This would prevent people from inadvertently getting on superhighways going in the wrong direction.
If the car was traveling from right to left as shown in FIG. 8 then the barrier would operate in the same manner as discussed in connection with FIG. 7.
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
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A speed bump for use on roadways which imparts a controlled jar to vehicles as they pass thereover. A retarding force is imparted to a downwardly depressible member responsive to the speed of the vehicle.
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[0001] The present patent application claims priority to U.S. Provisional Patent Application No. 60/468,938, filed May 8, 2003, incorporated by reference herein in its entirety.
FIELD OF INVENTION
[0002] The present invention relates to a method to quantitatively describe the formation heterogeneity at the resolution scale of the imagery and, more particularly, to a method that applies the techniques of geometric statistics (geostatistics) to borehole imagery measurements.
BACKGROUND OF THE INVENTION
[0003] Borehole imagery is a major component of the wireline business (for example, Schlumberger's FMI™, Formation MicroScanner, OBMI™ Tools), and an increasing part of the logging while drilling business (Schlumberger's GeoVision™) (as described by Tilke, “Imagery in the Exploration for Oil and Gas”, published in Castelli et al., Image Databases (2002) Wiley, page 608, incorporated by reference herein in its entirety). While these measurements contain abundant data about the subsurface, it remains a challenge to automatically extract the important geological and petrophysical knowledge contained therein. The precise and efficient extraction of this knowledge from the images increases their utility, and therefore will increase the demand for these measurements.
[0004] Schlumberger has a long interest in developing techniques for automatically interpreting and extracting features from borehole imagery. Many of the most successful techniques in this area have been implemented in Schlumberger's BorTex™, PoroSpect™ and BorDip™ applications. BorTex™ semi-automatically segments an image into areas of similar texture that correlate with different rock types. BorTex™ can further identify “spots” and “patches” from images for quantification of vugs and connectivity in carbonates. PoroSpect™ on the other hand transforms an FMI™ conductivity image to a porosity image (see below), then affords the opportunity to analyze the porosity distributions in a statistical sense. Finally, BorDip™ analyzes discontinuities in the images to automatically identify stratigraphic and structural dips, and fractures.
[0005] A limitation of these approaches to automated heterogeneity analysis from borehole image interpretation is that they involve treating the borehole image as a two-dimensional image to which image processing techniques are applied.
[0006] While there is a long history of academic and industrial approaches to the automated interpretation and modeling of borehole imagery (e.g. BorTeX™), there is limited academic or applied work on the application of geostatistical techniques for this purpose.
[0007] The recognition that borehole images can be mapped to petrophysical properties is well understood (see Delhomme et al., “Permeability and Porosity Upscaling in the Near-Wellbore Domain: The Contribution of Borehole Electrical Images”, (1996) SPE 36822 and Newberry et al., “Analysis of Carbonate Dual Porosity Systems from Borehole Electrical Images”, (1996) SPE 35158, incorporated by reference herein in their entireties).
[0008] Perhaps the best established transformation is that from resistivity to porosity space using the classic Archie saturation equation (see Fanchi et al., “Shared Earth Modeling” (2002) Elsevier, page 306, incorporated by reference herein in its entirety):
S w n = aR mf Φ m R xo ( 1 )
[0009] where S w is the saturation of the wetting phase (0.00-1.00), n is the saturation exponent, α depends on the tortuosity (0.35-4.78), R mf is the resistivity of the mud filtrate, φ is the porosity (0.00-1.00), m is the cementation exponent (1.14-2.52), and R xo is the resistivity of the flushed zone.
[0010] This relationship can be rearranged as follows:
Φ = ( aR mf S w n R xo ) 1 m ( 2 )
[0011] The PoroSpect™ application transforms the resistivity image data into porosity (φ) using Equation (2) where the remaining Archie's parameters are either input by the user or derived from other logs. A 1.2-inch vertical window is then applied to these data to generate and analyze a porosity distribution histogram for every depth (0.1 inch vertical spacing) (see Newberry et al., “Analysis of Carbonate Dual Porosity Systems from Borehole Electrical Images”, (1996) SPE 35158). This technique has proven very powerful in identifying some aspects of porosity distribution such as dual-porosity. Note however, this technique effectively collapses the image data into a histogram, discarding spatial information (other than depth). It does not consider the three-dimensional geometry of the FMI™ sensors in the borehole.
[0012] An approach to analyze the geostatistical variation of porosity as seen in FMS borehole imagery has been suggested previously (see Delhomme et al., “Permeability and Porosity Upscaling in the Near-Wellbore Domain: The Contribution of Borehole Electrical Images”, (1996) SPE 36822). It is suggested that the geostatistics on a single pad can be analyzed for fine scale heterogeneity, and intermediate scale heterogeneity can be modeled across pads.
[0013] One object of the present invention is to provide a method to model formation heterogeneity in terms of geological or petrophysical properties.
SUMMARY OF THE INVENTION
[0014] The present invention describes a novel approach to quantitatively describe the formation heterogeneity at the resolution scale of the imagery by applying the techniques of geometric statistics (geostatistics) to borehole imagery measurements (FMIM, Formation MicroScanner, OBMI™, etc.). It is noted that while the examples provided herein are directed to Schlumberger's FMI™ tool, the method may be applied to nearly all borehole imagery tools.
[0015] The geostatistical parameters, which represent the geological and petrophysical heterogeneity at the scale of the borehole image measurements, are then used to model the heterogeneity at measurement scales representing larger volumes of investigation (e.g. core plug, porosity logs, resistivity logs). These modeled parameters can then be used to describe the uncertainty in formation properties at any scale given measurements taken at a particular scale and are presented as single channel logs.
[0016] An immediate application of this technique is found in carbonates where lateral heterogeneity calls in to question the utility of conventional logging tools (e.g. porosity) to determine average formation properties. The technique may also be applied to the interpretation of clastics.
[0017] The present invention provides an approach to automated borehole image interpretation that treats the borehole as a three-dimensional entity in which the tool sensors measure a geological or petrophysical property. This property is thereby modeled in three-dimensions, and the techniques of modern geometrical statistics (geostatistics) can be applied.
[0018] A significant benefit of modeling the three dimensional geostatistics of the borehole is that geometric and statistical transformations can then be applied to the modeled parameters. An immediate application of this is the ability to “upscale” the modeled parameters. As will be described below in this document, this allows us to ascribe a heterogeneity index (defined below) to some of the other measurements whose values are averaged over larger volumes of investigation, e.g. core plugs and logging tools.
[0019] The present invention treats borehole images as three-dimensional measurements of the geological and petrophysical properties of the rock. The technique then uses the established techniques of geostatistics (see Clark, Practical Geostatistics , Elsevier Applied Science Publishers, Ltd. (1984), incorporated by reference herein in its entirety) to model the three-dimensional geological and petrophysical heterogeneity of the rock in the region of the borehole.
[0020] The present invention also discusses the presentation of the modeled parameters as single channel logs summarizing the geology and petrophysics observed by the imagery.
[0021] These geostatistical parameters, which represent the statistical variability at the scale of the borehole image measurements, are then used to model the statistical variability at measurement scales representing larger volumes of investigation (e.g. core plug, porosity logs, resistivity logs). These modeled parameters can then be used to describe the accuracy of these larger scale measurements in representing the mean formation properties and differences expected between them due to their differing volumes of investigation.
[0022] Examples are presented where this technique has been applied to a carbonate well, where lateral heterogeneity calls in to question the accuracy of conventional logging tools (e.g. porosity).
[0023] One embodiment of the present invention is a method of characterizing a borehole traversing an earth formation, comprising: (a) obtaining an array of data from a formation characterization tool, wherein the data describes a section of the borehole; (b) computing at least one spatial characteristics describing the relative position of pairs of data; (c) assigning the pairs of data to bins based on the spatial characteristic, wherein the size of the bins are selected based on the resolution of the tool; (d) transforming the data to petrophysical properties of the borehole; (e) determining the variance of each bin; (f) developing a model of the variances; (g) determining the at least one geostatistical parameter using the model; and (h) upscaling the geostatistical parameter to characterize a region of the earth formation. The method may further include generating a heterogeneity index log using the geostatistical model parameters. It is preferred that the array of data describes a substantially continuous section of borehole. While non-continuous data may be used, this data may result in “empty” bins and gaps in the geostatical model. The coordinates of the data (relative to the region of investigation) may be determined, such as based on the borehole geometry, tool geometry, and tool orientation which are obtained as part of the measurements. Accordingly, the spatial characteristics describing pairs of data may be based on the distance between data pairs, the depth of data pairs in the borehole or within the region of investigation, and the orientation of the data pairs (i.e. the azimuth). The data may be upscaled to a three-dimensional model using the relative or absolute distance between data pairs and the orientation or azimuth of the data pairs.
[0024] The variance model may be developed by (a) computing the variance of the spatial characteristic of each bin; (b) computing an experimental semi-variogram using the variances; (c) deriving a model semi-variogram from the experimental semi-variogram; and (d) determining the geostatical parameters using the model semi-variogram.
[0025] The method of the present invention may be implemented using a computer program product for processing and interpreting borehole data, comprising a computer useable medium having computer readable program code embodied in the medium for processing borehole data, the computer program product having (i) computer readable program code means for computing spatial characteristics describing the relative position of pairs of data, wherein the data describes a borehole; (ii) computer program code means for assigning said pairs of data to bins based on the spatial characteristic, wherein the size of the bins are selected based on the tool used to collect the data; (iii) computer program code means for transforming the data to petrophysical properties of the borehole; (iv) computer program code means for determining the variance of each bin; (v) computer program code means for developing a model of the variances; (vi) computer program code means for determining at least one geostatistical parameter using the model; and (vii) computer program code means for upscaling the geostatistical parameter to characterize a region of the earth formation. The computer program may further comprise a computer program code means for generating a heterogeneity index log using the geostatistical model parameter.
[0026] Further features and applications of the present invention will become more readily apparent from the figures and detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] [0027]FIG. 1( a ) is a flow chart showing one embodiment of the method of the present invention; FIG. 1( b ) shows one implementation of the present invention.
[0028] [0028]FIG. 2( a ) is a schematic of the FMI™ Tool having the four pairs of pads and flaps generating 192 measurements per depth; FIG. 2( b ) is a detail of one pad.
[0029] [0029]FIG. 3 is a plan view of borehole illustrating (a) the distribution of FMI™ sensors around perimeter of a 8.5 inch diameter borehole and (b) the vector of length L separating sensors S 1 and S 2 with angular separation θ in hole of radius R is given by
L = 2 R sin ( θ 2 ) .
[0030] [0030]FIG. 4 is a schematic illustration of a three dimensional extension of the present invention.
[0031] [0031]FIG. 5 is a histogram illustrating frequency of sensor pairs per 0.2 inch sampling bin for 8.5 inch diameter hole; Bin 1 is 0-0.2 inch, Bin 2 is 0.2-0.4 inch, etc.
[0032] [0032]FIG. 6 is a horizontal semi-variogram (for the middle of the interval of FIG. 12) illustrating experimental data from the FMI™ as well as the modeled semi-variogram for FMI™, core plug, a high resolution tool, and a low resolution tool.
[0033] [0033]FIG. 7 is a conceptual diagram of a series of 11 core plugs and their measured porosity values taken from a homogeneous carbonate.
[0034] [0034]FIG. 8 is a conceptual diagram of a series of 11 core plugs and their measured porosity values taken from a heterogeneous carbonate.
[0035] [0035]FIG. 9 is a conceptual diagram illustrating the relative volumes of FMI™ measurements, core plugs, and a density log.
[0036] [0036]FIG. 10( a ) and ( b ) are graphs of modeled semi-variogram parameters as a function of depth and (a) lag (L) and (b) sill (C) for various volumes of investigation ν: FMI™, Core Plug, High-resolution density porosity, Low-resolution density porosity.
[0037] [0037]FIG. 11 is a log of heterogeneity index Ψ φ,ν as a function of depth in the borehole.
[0038] [0038]FIG. 12 is a porosity image of 30 inch interval with fossiliferous layer containing 1-2 inch diameter rudists and having a mean porosity of approximately 18%.
[0039] [0039]FIG. 13 is a porosity image of 22 inch high interval exhibiting mean porosity of approximately 22%.
[0040] [0040]FIG. 14 is a horizontal semi-variogram for the middle of the interval displayed in FIG. 13.
[0041] [0041]FIG. 15 is a composite porosity log displaying logging tool porosity with core plug porosity.
DETAILED DESCRIPTION OF THE INVENTION
[0042] As noted above, one embodiment of the present invention provides an output of a series of single channel logs describing the geological and petrophysical heterogeneity of a borehole. While porosity (φ) will be used as a measure of this heterogeneity, and FMI™ imagery will be used as the source measurements, one skilled in the art will recognize that other parameters and imagery sources may be suitably employed in accordance with the present invention.
[0043] In one embodiment, the generation of the heterogeneity logs involves the following steps, as shown in FIG. 1( a ):
[0044] 1. Obtain an array of data describing (or imaging) a section of the borehole wall, for example, a 2D array of pixels describing the borehole wall 10 .
[0045] 2. Compute the spatial characteristics describing the relative position of the pairs of data 15 . This may include calculating the coordinates (such as the 3D Cartesian coordinates) of the data from hole geometry, tool geometry, and tool orientation to determine the depth of, distance between or orientation (azimuth) of the data pairs.
[0046] 3. Identify appropriate bins, such as based on the spatial characteristics selected and/or the resolution of the tool 20 . This may be performed for a given depth(s). The size of these bins will be dependent upon the tool used to acquire the data.
[0047] 4. Assign data pairs to bins representing similar spatial relationships 25 .
[0048] 5. Transform the data values as desired 30 , for instance normalized FMI™ resistivity (R xo ) pixels may be transformed to porosity (φ) pixels. Other possibilities include but are not limited to grouping the pixels by their measurement value into bins using either new or preexisting image analysis techniques.
[0049] 6. Determine the φ variance for each bin 35 and develop a model of the variance 40 . This variance model may be developed by computing the variance of each bin 40 a , computing an experimental semi-variogram 40 b by computing the φ variance for each bin, then deriving a model semi-variogram from the experimental semi-variogram 40 c , thereby determining the modeled geostatistical parameters 40 d and making them available for further processing or display.
[0050] 7. Determine the geostatistical parameters from the modeled variance 45 and compute the same parameters for measurements with larger volumes of investigation using upscaling approaches 50 .
[0051] 8. The up-scaled geostatistical model parameters can then be used to generate heterogeneity index logs for corresponding core and logging measurements 55 .
[0052] These methods may be implemented on a computer readable medium, such as one shown in FIG. 1( b ) having a program carrier 60 , a storage device 65 , a processing unit 70 , a keyboard ( 75 ) or other data input mechanism and a display 80 or other output mechanism.
[0053] These steps and potential extensions are described in greater detail in the following sections. While the example provided herein is a vertical well of constant width having horizontal layers, the method may be easily extended to deviated wells with varied width, having nonhorizontal dip and azimuth.
[0054] Compute Three-Dimensional Sensor Geometry
[0055] Borehole imaging tools produce images of the measured parameter (resistivity, acoustic impedance, density, etc.) on the rock face. At a given depth, the exact geometry of the pixels is therefore a function of the hole diameter at that location and the sensor configuration. Thus, given the orientation of the borehole, the azimuthal orientation of the tool, and the diameter of the hole (all of which are recorded), the 3D Cartesian coordinate of every pixel is known.
[0056] Note that while the technique presented here is general, for simplicity the FMI™ Tool is used to illustrate the technique. It is noted, however, that the present methodology may be easily adapted for use with other imaging tools.
[0057] The FMI™ Tool (shown in FIGS. 2 ( a ) and ( b )) is comprised of four pairs of pads and flaps. Each pad and flap (see FIG. 2( b )) has 24 resistivity sensors resulting in 192 sensors per depth (8×24). The four arms of the tool expand in the borehole so that the pads and flaps press against the rock face. At a given depth, the sensor geometry is therefore a function of the hole diameter at that location (shown in FIGS. 3 ( a ) and ( b )). Thus, given the orientation of the borehole, the azimuthal orientation of the FMI™ Tool, and the diameter of the hole (all of which are recorded); the 3D position of every sensor is known.
[0058] While the examples presented here in are from a vertical well of constant diameter (8.5 inches) to simplify the analysis, the methodology may be extended to other configurations. FIG. 4 is a schematic diagram illustrating a section of a borehole (depicted as a cylinder) intersected by a geological bed (Plane B). The vertical Plane A is coincident with the borehole axis and the maximum apparent dip (δ) of the bedding relative to the borehole. Knowledge of the sensor positions is useful to extend the theory illustrated in FIG. 3( b ) and Equation (5) below on the ellipse formed by the intersection of Plane B with the borehole (shaded area in FIG. 4). The two parameters r (apparent radius) and β (apparent azimuth) are computed. The following equations express these values in terms of a (the azimuth of the sensor), δ (dip to the sensor), and R (the radius of the borehole) which may be determined using tool measurements:
r 2 =R 2 (1+cos 2 α tan 2 δ) (3) sin 2 β = sin 2 α 1 + cos 2 α tan 2 δ ( 4 )
[0059] Identify Two-Point Sensor Pairs
[0060] For the two-point geostatistical analysis, sensor pairs should be identified. Measurements are obtained over a continuous logging run; however, for simplicity, this example considers data collected from sensors at over a determined depth, and ignores the orientation of the vectors between the sensors (only their magnitude is considered). The full three-dimensional analysis is a straightforward extension of this reduced approach.
[0061] As noted above, there are 192 sensors per depth in the FMI™ Tool. As such, there are
192 × 191 2 = 18336
[0062] possible sensor pairs. Once the 3D coordinate of each sensor is known, then the Euclidean distances between sensor pairs are trivially calculated (see FIGS. 3 ( a ) and ( b )):
L = 2 R sin ( θ 2 ) ( 5 )
[0063] Assign FMI™ Sensor Pairs to Bins with Similar Lags
[0064] For geostatistical analysis, these sensor pairs should be grouped by pairs into bins with similar L (lags, also referred to as relative distance). The maximum number of bins possible to achieve maximum resolution of the semi-variogram structure is preferred, but too small a bin size will result in aliasing (see Bloomfield, “Fourier Analysis of Time Series: An Introduction”, 2 nd Edition (2000) Wiley, page 261, incorporated by reference herein in its entirety). The correct minimum bin size is dictated by the Nyquist Frequency which is twice the sensor spacing (0.1 inches), i.e. 0.2 inches. For the 8.5-inch diameter hole example, this results in 43 bins of equal size (except the last which is 0.1 inches). Because of the trigonometric effects and non-uniform distribution of sensors as illustrated in FIGS. 3 ( a ) and ( b ), the number of sensors in each of the 43 bins is not uniform as shown in FIG. 5.
[0065] Transform Normalized FMI™ Resistivity Image to Porosity Image
[0066] Once the sensor pairs and bins have been identified, the resistivity image is mapped to a geological or petrophysical property, so that this property can be analyzed in a geostatistical sense. While it is possible to use any attribute extracted from the resistivity image, for the purposes of this document, PoroSpect™ will be mirrored and Archie's transformation will be applied to analyze the porosity φ of a each pixel of the image (see Equation (2)).
[0067] In applying Archie's transformation to the entire well, it is assumed that the Archie parameters in Equation (2): S w , m, n, α, and R mf are constant over a given depth window in the borehole
[0068] This assumption allows Equation (2) to be expressed as:
φ=λ R xo −γ m (6)
[0069] where
λ = ( aR mf S w n ) 1 m ( 7 )
[0070] One of the assumptions, therefore, is that λ is constant for a given depth, but it can vary along the length of the well.
[0071] Rather than estimating λ from unknown Archie parameters, it can be eliminated from Equation (6) in the following manner.
[0072] From Equation (6), and the previous assumptions, at a given depth:
〈 Φ 〉 = λ 〈 R xo - 1 m 〉 where 〈 〉 ( 8 )
[0073] denotes the expectation or mean of the enclosed expression.
[0074] Equations (7) and (8) can be combined to eliminate λ yielding:
Φ 〈 Φ 〉 = R xo - 1 m 〈 R xo - 1 m 〉 where 〈 R xo - 1 m 〉 ( 9 )
[0075] represents the mean value of R xo −γ m at the depth of interest and can be obtained from the resistivities of the image pixels, and
〈 Φ 〉
[0076] represents the mean porosity at the given depth and can be obtained from conventional low resolution porosity logging tools. This approach of using a low resolution measurement to calibrate a high resolution measurement has been described previously (see Flaum et al., “Enhanced Resolution Processing of Compensated Neutron Logs”, (1986) SPE 15541 (incorporated by reference herein in its entirety).
[0077] Note, due to heterogeneity
〈 Φ 〉
[0078] has its own heterogeneity index (defined below) because it is a logging measurement. This uncertainty can be integrated into the final heterogeneity calculations.
[0079] Compute Experimental Semi-Variogram
[0080] Now that the porosity data has been acquired and the bins defined, sample variance for each bin h(i) can be computed with the conventional experimental variogram equation (see Clark, Practical Geostatistics , Elsevier Applied Science Publishers, Ltd. (1984)):
2 γ * [ h ( i ) ] = 〈 ( Φ t + h - Φ t ) 2 〉 ; i = { 1 , 2 , … , k } where 〈 〉 ( 10 )
[0081] again denotes expectation or mean, and k is the number of bins.
[0082] Model Semi-Variogram
[0083] For the purposes of this analysis, a simple semi-variogram model has been defined to fit the experimental data from Equation (10):
γ( h )= C 0 +C[ 1− e −(h/L) 2 ] (11)
[0084] Thus, the model semi-variogram γ is a function C 0 (nugget effect) and the Gaussian model C (sill) and L (range or correlation length).
[0085] Over the past 20 years that has been a great deal of research into the optimal way to fit a model semi-variogram of Equation (11) to the experimental semi-variogram of Equation (10) (see Cressie, “Fitting Variogram Models by Weighted Least Squares”, Mathematical Geology (1985) 17, pages 563-588 (incorporated by reference herein in its entirety) and Zhang et al., “On the Weighted Least-Squares Method for Fitting a Semivariogram Model”, Computers and Geosciences (1995) 21, pages 605-608). It was found that the method of Zhang et al. yields the most satisfactory results. This method involves minimizing the cost criterion J (λ):
J ( λ ) = ∑ i = 1 k N h ( i ) h ( i ) 2 [ γ * ( h ( i ) ) - γ ( h ( i ) ) ] 2 ( 12 )
[0086] where N h(i) is the number of pairs in bin h(i).
[0087] In FIG. 6, the resulting model semi-variogram is plotted along with the experimental semi-variogram. Superimposed on the experimental data obtained from the porosity image are model variograms for FMI, Core Plug, High Resolution Tool, and Low Resolution Tool. In the experimental data, note the sill with φ 2 =0.00077 (φ=2.8%) reached at a lag of approximately 2 inches. This analysis can be repeated at every depth with imagery in the borehole. The resulting vectors of C 0 , C, and L can then be plotted as conventional logs. Examples of this is illustrated in FIGS. 10 ( a ) and ( b ).
[0088] Upscaling
[0089] Now that the experimental semi-variogram observed at the small (e.g. FMI™) scale has been modeled, the model may be upscaled to other volumes of investigation.
[0090] [0090]FIG. 7 is a conceptual design of a series of 11 core plugs and their measured porosity values taken from a homogeneous carbonate. For the homogeneous core plugs, the measured porosity at the core plug scale does not vary. By contrast, for the heterogeneous core plugs of FIG. 8, the measured porosity at the core plug scale is highly variable, depending on whether an individual plug intersects a large hole or a low porosity cemented region. A porosity measurement with a larger volume of investigation (such as a density tool) would read an average of a few plugs, thus having a smaller variance.
[0091] In addition to FMI™ and core plug measurement volumes, two logging tool measurement volumes have been considered in this analysis: the high resolution and low resolution porosity tools. The modeled dimensions of these various measurement volumes are listed in Table 1.
TABLE 1 Dimensions of modeled rectangular prism volumes of various measurements Width Height Depth Volume Volume Measurement (in) (in) (in) (in 3 ) (relative) FMI ™ Sensor 0.1 0.1 0.1 0.001 1x Core Plug 1.0 1.0 1.0 1.0 1,000x High Resolution Tool 3.0 3.0 3.0 27.0 27,000x Low Resolution Tool 3.0 12.0 4.0 144.0 144,000x
[0092] [0092]FIG. 9 is a conceptual diagram of the relative volumes (scale effects) of FMI™ measurements, core plugs and a density tool. A set of porosity measurement taken with the density tool at the location of each core plug reads the average of numerous core plugs and will thereby have a smaller variance than the same set of core plugs. Because the average measurements taken by the porosity tool will cover overlapping regions, there will not be a large variance between measurements. By contrast, FMI™ measurements have a larger variance than core plug measurements.
[0093] If two finite volumes of investigation ν (small volume) and V (large volume) are considered, then it is possible to derive the geostatistical parameters for V (i.e. C V 0 , L V and C V ) from the modeled geostatistical parameters for ν (i.e. C ν 0 , L ν and C ν ).
[0094] To upscale the nugget effect C 0 in Equation (11) it can be shown (Frykman et al., “Geostatistical Scaling Laws Applied to Core and Log Data”, (1999) SPE 56822, incorporated by reference herein in its entirety):
C V 0 = C v 0 v V ( 13 )
[0095] It can also be shown (see Frykman et al.) that the range (L) in Equation (11) increases as a function of the increase in volume size:
L V =L ν +(| V |−|ν|) (14)
[0096] where |V| and |ν| are the dimensions (lengths) of the volumes V and ν in the direction of L.
[0097] Finally, to upscale the modeled sill C in Equation (11), the concept of the point scale sill (C p ) is introduced. C p is defined as the sill for an infinitesimally small volume of investigation. Then, for the small finite volume ν, the decrease in sill is defined as follows:
C p −C ν =C p {overscore (Γ)}ν (15)
[0098] where C p {overscore (Γ)}ν is the point-scale sill within the volume ν, and {overscore (Γ)}ν is the normalized point-scale sill in ν (defined below in Equation (17)).
[0099] Equations (14) and (15) are then combined to eliminate the point scale sill C p yielding the following definition for C V :
C V = C v 1 - Γ _ V 1 - Γ _ v ( 16 )
[0100] The normalized point-scale sill in ν is obtained from the double volume integral:
Γ _ v = 1 v 2 ∫ v ∫ v Γ p ( x _ - y _ ) x y ( 17 )
[0101] where ┌x−y┐, is the Euclidean distance between points {overscore (x)} and {overscore (y)}, and Γ p is the normalized point scale model semi-variogram expressed as:
Γ p ( x _ - y _ ) = 1 - - ( x _ - y _ L v - v ) 2 ( 18 )
[0102] where L ν −|ν| is the modeled point scale range form Equation (11).
[0103] Similarly, {overscore (Γ)}ν is expressed as:
Γ _ V = 1 V 2 ∫ V ∫ V Γ p ( x _ - y _ ) x y ( 19 )
[0104] Having upscaled the geostatistical parameters to the larger measurement volumes (Table 1) over the entire relevant depth range of the borehole, it is now possible to present these data as well logs (see FIGS. 10 ( a ) and ( b )). Note that L increases as ν increases and C decreases as ν increases.
[0105] Construct Heterogeneity Index Logs for Porosity Measurements
[0106] For the purposes of this discussion, heterogeneity Index Ψ V is defined as:
[0107] The standard deviation due to heterogeneity of a measurement that samples a volume V.
[0108] In other words, measurements sampling a volume V over volumes separated by a distance greater than L V (Equation (14)) will vary with a standard deviation Ψ V . Further, the sample variance due to heterogeneity is then given by Ψ V 2 .
[0109] For a simple model semi-variogram, the magnitude of the sill is equivalent to the sample variance (see Clark, Practical Geostatistics , Elsevier Applied Science Publishers, Ltd. (1984)). Ψ V can therefore be expressed in terms of the proposed upscale parameters C V 0 and C V .
Ψ V 2 =C V 0 +C V (20)
[0110] Thus, Equation (20) allows the computation of the heterogeneity index for all of the idealized volumes of Table 1 at each imaged depth in the well. This is illustrated by the example heterogeneity index log (Ψ φ,V as function of depth) in FIG. 11. Note that this interval exhibits significant heterogeneity at all scales; further, Ψ is as high as 12% for the FMI scale and 9% for the core plug scale.
[0111] Porosity logs for a particular tool (e.g. density porosity), or measurement (e.g. core plug) can then be expressed with heterogeneity index envelopes as shown in FIG. 15.
[0112] Discussion
[0113] [0113]FIG. 13 is a section of the reservoir having moderate porosity (22%) and relatively small objects less than an inch in diameter. The semi-variogram from this section (see FIG. 14) illustrates a relatively short range (approximately 0.4 inches) corresponding to the visual size of the objects. [This can be compared to the interval presented above in FIG. 12, with a relatively long range of 0.86 inches.]
[0114] While the different variogram ranges appear to be consistent with the different geology in these intervals, the effect on the upscaled heterogeneity is perhaps more interesting. The short range seen in FIG. 14 is responsible for the relatively small upscaled heterogeneity index compared to that in FIG. 6. Note that the FMI™ scale sill with (φ 2 =0.00029(φ=1.7%) is reached at a lag of approximately 1 inch. Also note that the very low upscaled sills, e.g. φ 2 coreplug =0.000036(φ=0.6%), result from the effect of the relatively low range (as compared to FIG. 6).
[0115] The effect is computed from the upscaling equations. This predicted relationship between short range yielding greater suppression in upscaled heterogeneity also intuitively makes sense: small objects will not be resolved when the sample volume is large, while large objects will be resolved. Thus, it is clear that an understanding of the geostatistics and varying ranges is preferred to reconcile the heterogeneity observed at the different scales of measurement.
[0116] A comparison of the predicted heterogeneity at the core plug scale of measurement with actual core plug porosity measurements is illustrated in FIG. 15. In both the heterogeneous and homogeneous intervals, the predicted and observed core plug heterogeneity are remarkably consistent. Therefore, the apparent discrepancy can be explained by heterogeneity. Also shown in this figure is the ±2Ψ core plug envelope around the logging tool porosity. It is noted that, as predicted, approximately 2σ of the core plug measurements fall within the heterogeneity index envelope. Further, the log straddles a heterogeneous zone above (0-32 feet) and a homogeneous zone below (32-70 feet). The differences in heterogeneity between the two zones are reflected in both the heterogeneity index log and the core plug measurements.
[0117] While the invention has been described herein with reference to certain examples and embodiments, it will be evident that various modifications and changes may be made to the embodiments described above without departing from the scope and spirit of the invention as set forth in the claims.
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A method of characterizing a borehole traversing an earth formation including (a) obtaining an array of data from a formation characterization tool, wherein the data describes a section of the borehole; (b) computing at least one spatial characteristic describing the relative position of pairs of data; (c) assigning said pairs of data to bins based on the spatial characteristic, wherein the size of the bins are selected based on the tool; (d) transforming the data to petrophysical properties of the borehole; (e) calculating the variance of each bin; (f) developing a model of the variances; (g) determining at least one geostatistical parameter using the model; and (h) upscaling the geostatistical parameters to characterize a region of said earth formation. The method may further include generating a heterogeneity index log using the geostatistical model parameters. The method may be implemented using a computer program product for processing and interpreting borehole data.
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FIELD OF THE INVENTION
This invention relates generally to video imaging, and, in particular, to tracking and processing video images from multiple sources and reducing video motion information into a mathematical representation of the tracked images.
BACKGROUND OF THE INVENTION
Television sporting event broadcasts add excitement and an added dimension of participation through the use of slow motion and normal speed replay of an especially exciting or controversial portion of the game or event. For example, during a televised tennis match, viewers expect to see a sequence of spectacular play repeated, whether in slow motion or normal speed, with televised commentary accompanying and describing the replay. However, because of the finite number of cameras used to videotape an event, the best angle with which to observe a particular portion of play is not always available for replay. Unavailability of a well placed camera becomes increasingly vexing to viewers during an especially controversial play, viewers frequently desiring to observe a controversial play or game sequence from a viewing position which best represents the controversial aspects of the play or sequence.
Additionally, several sports also permit a review of a controversial officiating call through the observed replay of game video. A similar problem with camera location can occur in these instances. A view of the action leading to the controversial call may not have been captured by any video camera, game officials or players obscuring the view of the action required to make a determination. The difficulty imposed by the absence of an appropriate view during these instances is amplified in those cases when no official was in a suitable position to make a reasonably based judgment call as to what had transpired and the official is forced to guess as to what occurred.
Further, sports such as auto racing and downhill skiing have incorporated video cameras within a participant's equipment to allow for a televised depiction of a "participant's eye view" as a sporting event unfolds. Because of limitations with the weight and size of video equipment, and the restrictive aspects therein, this technology has not readily lent itself to sports in which a player's speed, quickness, and agility, such as baseball, basketball, and tennis, are of paramount importance. The ability to televise a view of an athletic endeavor from a player's perspective would add another level of excitement to a televised sporting event. Therefore, what is needed is the ability reduce the variables associated with an actual live action game to a data bank and to reconstruct a synthetic animated version of a desired portion of active play from the data collected.
SUMMARY OF THE INVENTION
The present invention is a method and apparatus for creating a synthetic animated version of a live game in which the trajectory of a ball, puck, or other object can be described through a series of equations. The present invention utilizes a plurality of cameras to track ball position with at least two cameras while periods of active play are in progress, and transmits video signals to a digital processor which samples a two-dimensional position from each camera and triangulates an actual three-dimensional ball position in relation to a field of play. Three-dimensional ball positions are grouped on-line or off-line, utilizing a digital processor, into segments of unimpeded motion. A segment of unimpeded motion is a collection of ball positions during which ball motion is not acted upon by a player, obstruction, or playing surface. Each segment of unimpeded motion is fit with an equation descriptive of its trajectory and a collection of equations representing each segment of unimpeded motion are temporarily stored.
The beginning and end of each segment of unimpeded motion is punctuated with a point of interaction. A point of interaction is represented by a three-dimensional ball position at a time when a player, obstruction, or playing surface intervenes to alter the trajectory from the previous segment of unimpeded motion. In an embodiment of the present invention utilized within a tennis game, points of interaction are those ball positions where the tennis ball changes trajectory due to being struck with a player's racquet, due to striking the net, or due to striking the tennis court. However, factors such as air resistance and ball spin can be represented by an equation of a differentiable function approximating ball position within one continuous segment of unimpeded motion, and are therefore not considered points of interaction.
Points of interaction and the equations describing segments of unimpeded motion are both temporarily stored at a buffer or queue associated with an attendant storage device. The digital processor is programmed to make a determination as to whether each specific point of interaction is attributable to player intervention (e.g.--striking the ball with a racquet) or whether the point of interaction is attributable to a collision with the playing field or fixed obstructions (e.g.--the tennis court and net respectively). The determination is made on-line or off-line by a comparison of ball trajectories with respect to possible causes for a change of trajectory. If a specific point of interaction is attributable to player intervention, that point of interaction is flagged by the program running at a digital processor and stored to trigger an animated player interaction with the ball at that specific point of interaction during the creation of a synthetic animation of the actual live action game. An animation program is utilized to synthesize the animation. The animation program is resident at the digital processor or compatible computing equipment for near instantaneous synthetic reproduction, or game variables can be stored for future use. The animation program animates appropriate ball motion, player interaction, racquet speed and angle, and other variables consistent with game physics and human ergonomics. Animation techniques utilized in the present invention are equivalent to those used in the design of video games, and are well known to those skilled in the art. Additional realism is added to a synthesized animated game when player position, player extremities, and racquet position are further monitored, tracked, stored and utilized in conjunction with previously described variables for animation of the synthesized game.
Several uses exist for synthesis of an animated game based on a live action game which is able to be reduced and stored in a highly compressed form. One such use is in conjunction with live televised broadcasts of sporting events. A synthesized replay of interesting sequences of game play, rendered in high quality animation, are used in conjunction with conventional video of the event. A synthesized replay can be shown at normal speed, high speed, or in slow motion. The point of view of a replay is designated from any desired position or angle. Thus, in effect, a virtual camera is created which is operable to provide particularly insightful virtual camera pseudo-locations for a synthesized animation of a game or game sequence. The virtual camera is also operable as if it were a moving camera, its pseudo-path variable even within a sequence of play. One especially interesting possibility is to direct the virtual camera to synthesize an animated version of a game from a pseudo-location corresponding to eyes of a player.
The present invention may also be utilized as an officiating tool in those sports that allow review of an official's ruling or determination pertaining to a controversial officiating call. Actual video is still contemplated as being used, but in those situations when an appropriate view from a video camera is not available, the present invention is utilized and a pseudo-location is prescribed which allows the best view of the controversial game or match segment.
The present invention is also applicable for use over the Internet. Current modems are more than adequate to transmit the tracking data associated with a synthetic game. Tracking data is transmitted to Internet servers made available to subscribers. The tracking data can be broadcast over the Internet live, or in the alternative, a subscriber can access the database containing the tracking data at any convenient time. Another embodiment of the present invention further transmits a "play-by-play" audio track and calculated statistics (such as ball speed, player speed, distance traveled by player during a game, etc.) along with the tracking data used to synthesize the animated game. Software to support the synthesis of an animated game from the transmitted tracking data is operable at the PC of the subscriber user. Users are able to interact with the animation, that is, a user is able to designate a specific virtual camera's pseudo-location or designate a virtual camera view of the game from the perspective of one of the players.
Another embodiment of the present invention stores the tracking data from a plurality of games on a suitable storage device (such as a floppy disk or CD-ROM). A user installs a viewer program on a PC and accesses a desired synthetic game file from the floppy disk or CD-ROM. Again, users are able to interact with the animation, that is, a user is able to designate a specific virtual camera's pseudo-location or designate a virtual camera view of the game from the perspective of one of the players.
Although the present invention is particularly well suited for the synthetic animation of a tennis game, and is so described with respect to this application, it is equally applicable for use with any game in which the trajectory of a ball, puck, or other object can be reduced to the form of an equation or series of equations, or in other instances when object motion can be reduced to the form of an equation or series of equations.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be obtained from consideration of the following description in conjunction with the drawings in which:
FIG. 1 is a top view pictorial illustrating one embodiment of camera location in relation to a field of play, implemented within a two camera system and in accordance with the present invention; and
FIG. 2 is an exemplary flow chart illustrating the processes involved in the implementation of one embodiment of the present invention.
DETAILED DESCRIPTION
For clarity of explanation, the following illustrative embodiments of the present invention are presented as comprising individual functional blocks (including functional blocks labeled as "processors" or "microprocessors." The functions these blocks represent may be provided through the use of either shared or dedicated hardware, including, but not limited to, hardware capable of executing software. For example, the functional steps presented in FIG. 2 may be accomplished by a single shared processor, or in the alternative, the functional steps may be accomplished through a plurality of processors each performing one or more of the functional steps disclosed. Use of the terms "processor" or "microprocessor" should not be construed to refer exclusively to hardware capable of executing software. Illustrative embodiments of the present invention may comprise microprocessor and/or digital signal processor ("DSP") hardware, read-only memory ("ROM") for storing software performing the operations discussed below, and random access memory ("RAM") for storing intermediate calculations and final results. Very large scale integration ("VLSI") hardware embodiments, as well as custom VLSI circuitry in combination with a general purpose DSP circuit, may also be provided.
FIGS. 1 and 2, and the accompanying detailed description contained herein, are to be used as illustrative exemplary embodiments of the present invention, and should not be construed as the only manner of practicing the present invention. Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the following description. Details of the structure may be varied substantially without departing from the spirit of the invention.
FIG. 1 is a top view pictorial illustrating one embodiment of camera locations in relation to a field of play, implemented within a two camera system and in accordance with the present invention. The field of play shown in FIG. 1 is that of a tennis court 110 and the present invention will be described within the context of a tennis game, although the present invention may be utilized to synthesize an animated version of any game in which the trajectory of a ball, puck, or other object can be reduced to the form of an equation or series of equations, or in other instances when object motion can be reduced to the form of an equation or series of equations. A top view of the lines forming court boundaries associated with a tennis court (110) are illustrated as well as the net (115) at mid-court. Camera #1 120 and Camera #2 130 are each operable to view the entire field of play, including a height above the two-dimensional surface of play 110 that the tennis ball is not expected to exceed during play. Although no prescribed camera location is mandatory, criteria for selecting camera position include (i) positioning cameras to obtain the greatest resolution, that is, the greatest number of pixels for a given field of view, (ii) selecting camera location based on practical requirements such as accessibility or non-interference with the play of the game, (iii) positioning each camera so as to view the entire field of play, (iv) placing cameras in positions which maximize the contrast between the object to be tracked, a tennis ball in this example, and the background, and (v) placing cameras in positions which minimize the amount of non-game motion in the background of a camera's field of view, in order that interference with the ability to track tennis ball position and player position are minimized.
In an embodiment of the present invention which utilizes more than two cameras, it is not necessary that each camera is operable to view the entire field of play. However, at least two cameras are able to track the tennis ball position at each possible ball location within the field of play. Maintaining a system wherein ball position is displayed at every possible location within the field of view of at least two cameras ensures that triangulation can be used to determine ball position in three-dimensional space. An advantage of using more than two cameras is that each camera maintains a smaller field of view. Therefore, a constant number of pixels are used to monitor a smaller field of view and greater resolution and tracking ability are achieved.
Another advantage of using more than two cameras is evident when a ball trajectory path is directly along an imaginary line between two cameras in a two camera embodiment. Since there is no lateral component of ball motion discernible by either video display, lateral data is unobtainable and ball position in three-dimensional space cannot be determined. In a system with three or more cameras, a ball trajectory path directly between two cameras is not fatal, since a third camera is also monitoring ball position and trajectory. Triangulation, based on data from this third camera and any other camera (including one of the two cameras between which the ball is traveling), is viable and therefore ball position in three-dimensional space is determinable.
The relative height of individual camera placement is variable with respect to several embodiments. One embodiment of the present invention maintains video cameras at or near court level. Placing cameras at or near court level allows for quick setup and breakdown of video equipment prior to and after use with the present invention. Another embodiment of the present invention utilizes elevated cameras, either attached to poles, placed on scaffolding, or mounted on an electric or hydraulic manlift. Elevated cameras allow a camera to incorporate a greater portion of a playing field within a fixed focal length and minimize non-game background motion by eliminating a portion or the entire background of audience, spectators, and/or support crew and staff. Therefore, tracking ball and player motion during game play is performed with a greater degree of accuracy with the use of elevated cameras. In yet another embodiment of the present invention, camera position is not fixed but variable, that is cameras are movable during periods of active play. Implementing the present invention as a system utilizing movable cameras allows for the use of fewer cameras than a system not utilizing movable cameras.
FIG. 2 is an exemplary flow chart illustrating the processes involved in the implementation of one embodiment of the present invention. In step 210, a plurality of video cameras are arranged around the field of play in such a manner that at least two cameras are operable to view ball position at any point within the boundaries of the field of play and above the field of play to a height over which a ball in play is not expected to exceed. Camera video speed determines the quantity of frames per second captured by each camera. The greater the quantity of frames per second, the greater the available sampling rate of ball position and the greater the tracking accuracy of the present invention. Prior to commencement of processing a live action game in accordance with the present invention, each camera must be calibrated with respect to its field of view and known or measured field parameters. For example, after a field of view is established with Camera #1, court dimension parameters (based on known court dimensions and known or measured net height) are related to specific pixels of Camera #1 output within a program running on a digital processor (e.g.--a microprocessor, microcircuitry, or a digital signal processor). The program performing the necessary calculations and assignments may be implemented as a software and/or hardware combination running on a personal computer, a mini-computer, or some other general computing environment; or the program may run on a specially designed IC chip, microprocessor, or other hardware implementation, such as ASIC. A set of equations relating three-dimensional points in court coordinates to two-dimensional points (pixels) within the field of view of Camera #1 are computed using methods well known to those skilled in the art. One example for translating three-dimensional position to two-dimensional position is described in a book entitled "Three-Dimensional Computer Vision," O. Faugeras, MIT Press, 1993. The process is repeated for Camera #2 and each subsequent camera utilized. Therefore each camera utilized has a function mapped from known court (and net) positions to the position of pixels associated with a specific camera's two-dimensional output.
Once each camera has been calibrated, a live action game may commence. Each of the two or more cameras associated with the present invention transmits live action game video to a system digital processor running the corresponding software program, or a portion of the corresponding software program, in accordance with step 215. The processor tracks the position of the ball from the perspective of its pixel coordinates from each camera and samples that position, in accordance with step 220. Tracking a moving object against a relatively stationary background is well known to those skilled in the art, as is described in a book entitled "Three-Dimensional Computer Vision," O. Faugeras, MIT Press, 1993, for example. In one embodiment of the present invention, sampling the tracked ball position is performed at the microprocessor for each frame transmitted from each camera because a high sampling frequency results in an improved approximation of actual ball position when an animated facsimile of the live game is synthesized. In another embodiment of the present invention, sampling is performed less frequently. Sampling once per n frames, where n is an integer, is an alternative when a high degree of accuracy is not required, when the system's data storage capacity or the data transmission capacity limits are approached, or when the frame speed of the live video is much greater than the required sampling speed based on the anticipated maximum velocity of the tracked object. Conversely, a high speed video camera, because it transmits a greater number of frames per second, will therefore provide an improved approximation of actual ball position when an animated facsimile of the live game is synthesized.
In step 225, three-dimensional ball positions are determined by a digital processor which triangulates the relative positions of the tracked ball's pixel coordinates from concurrent frames from each of the cameras able to track the ball. The result is temporarily stored in system buffer memory. This process of triangulation is reperformed for each of the sampled positions in time, each result being temporarily stored in buffer memory. The result is a sequence of time dependent three-dimensional positions for the tracked ball. The sequence of tracked ball positions is examined by a program running on a digital processor, in accordance with step 230, for segments of unimpeded motion. Segments of unimpeded motion are those portions of ball trajectory between points of alteration. Points of alteration are those points at which the ball in play strikes the court surface, the net, or a player's racquet, and which mark a change in the equation used to describe the previous motion of the ball or a change in the ball's velocity vector. An equation is best fit to the data contained in each segment of unimpeded motion, in accordance with step 235, the equation describing motion between points of alteration. The equation used to describe trajectory during a segment of unimpeded motion can include the effects of air resistance and ball spin, if desired, depending upon the degree of accuracy required during reproduction of an animated game. One embodiment of the present invention represents the trajectory equation as the coefficients of a polynomial. A marked departure from an expected sample position based on a current trajectory's equation indicates that a point of alteration has occurred. This point of alteration is due to the ball's interaction with the court surface (bouncing off of the surface), the ball striking the net, or a player striking the ball with a racquet. A point of alteration indicates the beginning of a new segment of unimpeded motion, which is described by a new trajectory equation, and is valid until the next point of alteration occurs.
One exemplary embodiment of the present invention utilizes the following method for segmenting ball positions into segments of unimpeded motion and fitting equations to those segments, in accordance with steps 230 and 235. A sequence of actual three-dimensional points for ball position in time is:
H=V(T.sub.1), V(T.sub.2), . . . , V(T.sub.n)
which correspond to respective moments in time:
T.sub.1, T.sub.2, . . . ,T.sub.n
where each position in time has a three-dimensional representation of:
V(T.sub.i)=[V.sub.x (T.sub.i), V.sub.y (T.sub.i), V.sub.z (T.sub.i)]
Trajectory segments are described by polynomial equations of order K, where K is equal to or greater than 2. The first k points of sequence H, where k>K, are separately fit to polynomials of order K for each axis component of X, Y, and Z; thus obtaining a vector function in time:
V'(T)=[V.sub.x '(T), V.sub.y '(T), V.sub.n '(T)]
The polynomial fit is accomplished utilizing the method of least squares, which is a method well known to those skilled in the art. Calculation of a per-point square error is accomplished by application of:
E={||V'(T.sub.1)-V(T.sub.1) ||+||V'(T.sub.2)-V(T.sub.2) ||+ . . . +||V'(T.sub.k)-V(T.sub.k)||}/(k)
where each minus sign is a representation for vector subtraction, and
||V||=[V.sub.x *V.sub.x +V.sub.y *V.sub.y +V.sub.z *V.sub.z ]
If the value of E is greater than or equal to a given threshold value, THR 1 , then the first point from H is rejected (i.e.--treated as a missing point) and the above calculations are repeated for a second point of H. This process is continued until a set of k sequential points are found for which E is less than THR 1 . The first such point marks the beginning of a new segment of unimpeded motion. Next, the square error, E, is computed for the (k+1) th point, with respect to the function V'(T), and add this point to the segment of unimpeded motion, if E is less than a threshold value, THR 2 . This procedure is applied to the (k+2) th point and subsequent points, as long as E is less than THR 2 . The first point, r, for which E is not less than THR 2 marks the end of the current segment of unimpeded motion. The above procedure is repeated, starting at point r, to find the second, third, and subsequent segments of unimpeded motion. In effect, the above procedure measures position deviation from representative trajectory equations to determine the occurrence of a point of interaction.
Representative trajectory equations for contiguous segments of unimpeded motion, determined as above, intersect each other at a point of intersection. A point of interaction, (a.k.a., point of alteration) is an approximation of the point between segments of unimpeded motion at which the ball strikes or is struck by the court surface, the net, or a player's racquet, which point of interaction is derived from the point of intersection. Some three-dimensional position data points may be missing due to loss of contrast between a ball in active play and the video background, an inability to track a ball in active play because it exits the anticipated field of view of a video camera or cameras, an inability to track a ball due to excessive video background motion, or degradation of system video equipment. Missing data points do not pose significant difficulty with the operation of the present invention since a trajectory equation is simply the best fit equation for a given number of three-dimensional data points. Therefore, if data points are missing during a segment of unimpeded motion represented by a homogeneous equation, the missing data points are assumed to conform to and support the best fit equation for the data points which do exist. If the result of step 240 is affirmative and three-dimensional data points are missing near or at a point of alteration, then in accordance with step 245, the equation describing trajectory for the segment of unimpeded motion preceding the point of alteration in question and the equation describing trajectory for the segment of unimpeded motion succeeding the point of alteration in question are compared and solved to find a calculated time and position at which the point of alteration occurred. As each equation describing ball trajectory during a segment of unimpeded motion is developed, it is temporarily stored for use at the microprocessor, in accordance with step 250.
Since each point of interaction is identified and the segments of unimpeded motion between sequential points of interaction are known, ball position during a sequence of active play is known and an animated three-dimensional version of ball position can be reconstructed. However, in step 255, those points of interaction that are attributable to player interaction with the ball during active play are additionally identified. Knowing which points of interaction are attributable to player interaction allows for a reconstruction of an animated version of the game to reproduce player intervention when appropriate. That is, an animated player in the game reproduction strikes the ball at a specific point of interaction if and only if a specific point of interaction is attributed to a player striking the ball. The determination as to whether a point of interaction is attributable to player intervention is made by a comparison of ball trajectories before and after a point of interaction, considering velocity vectors, position of the point of interaction relative to the ground, net, poles, and anticipated location of a player. A space-time point of interaction, P, is attributed to player intervention if one of the following conditions exist: (i) the absolute value of the velocity of the ball after P is greater than the absolute value of the velocity of the ball immediately prior to P, or (ii) the coordinate of P related to height is above court level and the trajectory deviation is not attributable to the proximity of ball position in relation to the position of the net or the poles, or (iii) the coordinate of P related to height is at court level, is not attributable to the position of poles, and the equation describing motion after P is markedly distinguishable from the motion predicted as a result of a reflection from the court. If a specific point of interaction is attributable to player intervention, that point of interaction is flagged at the microprocessor and stored to trigger an animated player interaction with the ball at that specific point of interaction during the creation of a synthetic animation of the actual live action game. Information derived from the above calculations can be stored in a variety of mediums because of the high degree of compression represented by reducing a representation for motion to a group of equations and a group of points in time.
Having determined the trajectories of the ball and the points of interaction attributable to players, a three-dimensional animated version of a live action game is reconstructed in accordance with step 260. The technology to create program driven animation based on a sequence of parameters is well known to those skilled in the art. The present invention's animation program simulates the live action game based upon the previously determined game parameters; points of interaction, points of interaction that are attributable to player interaction, and the trajectory equations describing ball motion during each segment of unimpeded motion. The program animates appropriate ball motion, player interaction, racquet speed and angle, and other variables consistent with game physics and human ergonomics. Animation techniques utilized in the present invention are equivalent to those used in the design of video games and are well known to those skilled in the art. Video games receive control input parameters directly from a player interface whereas the present invention substitutes calculated values of points of interaction, points of interaction attributable to player interaction, and trajectory equations instead of the player interface associated with video games.
In one exemplary embodiment of the present invention, articulated three-dimensional models of player bodies are created using three-dimensional modeling or body scanning techniques. In addition, three-dimensional motion sequences are obtained by recording body movements of live tennis players, using motion capture technology. Such technology is provided, for example, by Motion Analysis Corporation, Santa Rosa, Calif., or desired sequences are generated by the BioVision Motion Capture Studios, San Francisco, Calif. Motion sequences are collected for players running, for racquet swing, and for strike motions. These sequences are then scaled to fit the anatomy of the created player body models.
To animate the motions of a player, motion sequences for running, racquet swings, and strikes are selected and assembled together, to approximately match the points of interaction attributed to player intervention. The final composite motion sequences then are applied to the created player models. This type of technology is well known to those skilled in the art and have been used for character animation in computer games by companies such as EA Sports, Atari, Interplay, Acclaim, Crystal Dynamics, and others. A real time rendering of a synthesized game can be presented over a personal computer or an even greater degree of graphical realism can be achieved utilizing a Silicon Graphics, Inc. (SGI) Onyx or similar platform.
Using points of interaction, attributing points of interaction to player interaction, and describing ball motion with trajectory equations, the present invention is able to synthesize and display an animated portion of a game. Animation is possible from any angle or perspective chosen. For example, a synthesized game may be selected to be viewed from the perspective of one of the players, from the position of a line judge, or from any other location. Although not required, ball speed and other motion statistics are available for display on the monitor concurrently with a display of the animated game.
Another embodiment of the present invention, in addition to tracking ball position, also tracks player position within the field of view. Tracking player position, based on techniques well known in the art and described in a paper entitled "A Camera Based System for Tracking People in Real Time" presented at the International Conference on Pattern Recognition in Vienna, Austria in August, 1996, adds an extra element of realism to the animated version of a live action game. In an embodiment that tracks ball position and player position, the animation program possesses information regarding actual player position and therefore will animate players during a synthesis of the live action game at the positions actually maintained during the live action game. Player position information in relation to ball position at a point of interaction is also used to determine whether a player in the actual game used a backhand or forehand to strike a ball and therefore animation of the appropriate stroke is utilized in the synthetic version of the game. In an embodiment of the present invention which tracks player position and ball position, the microprocessor stores and transmits additional data describing player position in time along with the previously described trajectory equations.
Another embodiment of the present invention, in addition to tracking ball and player positions, also tracks a player's hand and racquet position. Tracking body, extremity, and racquet positions, using a similar technique to that described above in relation to tracking player position, adds a further element of realism to the animated version of a live action game. An embodiment that tracks ball position, player position, and player extremity and racquet positions utilizes additional fields to maintain the new information. Even so, tracking information representing the essence of a game is in a highly compressed form and requires less than twenty Kbits/sec for proper transmission and synthesis of an animated version of a live game.
One embodiment of the present invention utilizes game tracking data to synthesize an animated version of a live action game sequence for use in conjunction with a live televised broadcast of the game. A synthesized replay of a particularly interesting or controversial sequence of game play, rendered in high quality animation, is used in conjunction with conventional video of the event. The point of view of a replay is designated from any position or angle. Thus, in effect, a virtual camera is created which is operable to provide particularly insightful views with various virtual camera pseudo-locations for a synthesized animation of a game or game sequence. The broadcaster determines a virtual camera pseudo-location which provides the best view or angle from which to view a synthesized animated game sequence. The broadcaster further specifies the desired synthesized replay speed. The virtual camera is also operable as if it were a moving camera, its pseudo-path variable even within a sequence of play. One especially interesting possibility is to direct the virtual camera to synthesize an animated version of a game from a constantly changing pseudo-location corresponding to the eyes of a player.
The present invention may also be utilized as an officiating tool in those sports that allow review of an official's live ruling or determination through the review of video tape of a sequence of play. Actual video is still contemplated as being used, but in those situations when an appropriate view from an video camera is not available, the present invention is utilized and a pseudo-location is prescribed which allows the best view of the controversial game or match segment.
The present invention is also applicable for use over the Internet. Current modems, able to transmit data at greater than twenty Kbits/sec, are more than adequate to transmit the tracking data associated with a synthetic game. Tracking data is transmitted to WWW servers made available to subscribers. The tracking data can be multicast over the Internet live, or in the alternative, a subscriber can access a data base containing the tracking data at any convenient time. Another embodiment of the present invention further transmits a "play-by-play" audio track and calculated statistics (such as ball speed, player speed, etc.) along with the tracking data used to synthesize the animated game. Software to support the synthesis of an animated game from the transmitted tracking data is present at the PC of the subscriber user. Users are able to interact with the animation, that is, a user is able to designate a specific virtual camera's pseudo-location or designate a virtual camera view of the game from the perspective of one of the players.
Another embodiment of the present invention stores the tracking data from a plurality of games on a suitable storage device (such as a floppy disk or CD-ROM). A user installs a viewer program on a PC and accesses a desired synthetic game file from the floppy disk or CD-ROM. Again, users are able to interact with the animation, that is, a user is able to designate a specific virtual camera's pseudo-location or designate a virtual camera view of the game from the perspective of one of the players.
Although the present invention is particularly well suited for the synthetic animation of a tennis game, and is so described with respect to this application, it is equally applicable for use with any trajectory of a ball, puck, or other object that can be reduced to the form of an equation or series of equations. Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention and is not intended to illustrate all possible forms thereof. It is also understood that the words used are words of description, rather than limitation, and that details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of all modifications which come within the scope of the appended claims are reserved.
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The specification relates to a method and apparatus for tracking object position during active segments of motion monitored from a plurality of video cameras, repetitively sampling object position, representing various object trajectories during active segments as equations, and synthesizing an animated version of the motion of the object from the representative equations. The present description is described in the context of synthesis of an animated version of a tennis game, although a representation of object motion of any sort is equally applicable, if the object motion is capable of being reduced to the form of an equation or series of equations. In a further enhancement, player position, player extremities, and player controlled objects (such as a racquet) are also tracked and sampled and utilized to provide an animation more faithfully reproducing player position, player motion and other game parameters.
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BACKGROUND OF THE INVENTION
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/592,656, Filed Jul. 30, 2004.
[0002] 1.Field of the Invention
[0003] This invention relates to roadway lighting. In particular, this invention relates to highway barrier lighting systems utilizing Light Emitting Diodes (LEDs).
[0004] 2. Description of Related Art
[0005] Conventional roadway lighting is accomplished with overhead light standards mounted to a structure (e.g. a crash barrier or other structure serving as a physical barrier). Conventional overhead luminaries are glary, and the light that is emitted is uncontrolled, resulting in light trespass. Light trespass is an issue when a viaduct or roadway passes over or near a populated area. Conventional overhead lighting systems provide relatively high light levels over a very large horizontal area including the shoulder. However, the edge or shoulder is not highlighted but rather visually blended into the roadway scene. The overhead and diffuse (multidirectional) nature of the conventional lighting does not enhance small target visibility. Small targets are visually lost under conventional roadway lighting.
[0006] In the field of roadway lighting, the desire to improve small target visibility has been frustrated by the use of conventional overhead lighting. Direct overhead illumination by unfocused (diffuse, propagating in all directions) light makes small objects/targets invisible. Previous unsuccessful attempts to address the issue of small target visibility include development of asymmetric overhead light sources.
[0007] A need remains in the art for an alternative strategy of lighting, which reduces light trespass into a populated or other light sensitive area, enhances small target visibility, and reduces energy consumption without compromising the safety of motorists/travelers.
SUMMARY
[0008] An object of the present invention is to provide roadway lighting systems which reduce light trespass, enhance small target visibility, and reduce energy consumption without compromising the safety of motorists/travelers. This object is accomplished using an LED system for providing lighting for roadways, as well as viaducts, pathways, etc. The LED system provides a strategy to mitigate light trespass and light pollution, and highlight roadway edges when motorist/traveler guidance is critical.
[0009] The present roadway lighting system provides guidance to travelers, defines the edges of the roadway, illuminates animals or vehicles stopped on the shoulder, indicates on-ramp and off-ramp locations, and enhances safety of merging traffic. The LED lighting system illuminates with uni-directional lighting and thereby eliminates the problem of small target visibility.
[0010] The LED system provides the necessary illumination to enhance motorist guidance (beam illumination) and highlight disabled vehicles (field illumination).
[0011] Additionally, the low energy use and long lamp life of LED systems reduces maintenance and operating costs.
[0012] Apparatus for lighting a roadway according to the present invention comprises an elongated barrier unit which is placed along the side of the roadway, generally parallel to the roadway. The barrier unit forms a recessed area in its roadway-facing surface. Within the recessed are of the barrier is installed an LED lighting element having a plurality of LEDs fixed in an elongated formation, oriented in a generally vertical orientation. This results in the LED lighting element providing an approximately horizontal sheet of light along the barrier.
[0013] The barrier might be, for example, a continuous cast-in-place barrier, a discrete crash barrier, a snow fence, a tunnel wall, a guard rail, or a bollard.
[0014] The roadway could be, for example, a viaduct, a highway, an on-ramp or off-ramp, or the like.
[0015] The LED lighting element can be powered in a number of ways, including via a generator, a battery, a fuel cell, a photovoltaic system, or an electrical power supply.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an isometric drawing showing a cast-in-place roadside barrier with a recessed LED lighting system according to the present invention.
[0017] FIG. 2 is an isometric drawing showing a crash barrier having a recessed LED lighting system according to the present invention.
[0018] FIG. 3 is a photograph of a barrier lighting system according to the present invention, in use.
[0019] FIGS. 4-1 through 4 - 5 (prior art) show electrical and lighting details for conventional roadway lighting systems, called luminaires.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Historically, roadways and highways are lighted using luminaries on tall poles located on the edge of the pavement. This LED system provides an alternative to tall poles by providing vertical or near vertical sheet illuminance on the shoulder, thus increasing small target visibility and highlighting any animals motorists stopped on the shoulder. Since the described LED luminaire lights the vertical or near vertical sides of the barrier, the outer edge of the road is highlighted and delineated, providing excellent guidance especially during inclement weather conditions.
[0021] Low power consumption, minimal light trespass on adjacent properties, and minimal light pollution, especially in non-urban areas, makes this an ideal lighting system for roadways and highways with continuous barriers, construction barriers or rail structures.
[0022] The strategy for lighting a viaduct, roadway, or pathway according to the present invention is shown in FIGS. 1-3 . FIG. 4 (prior art) shows some typical roadway lighting systems. The present strategy of lighting reduces light trespass into a populated or other light sensitive area, enhances small target visibility, and reduces energy consumption without compromising the safety of motorists/travelers.
[0023] FIG. 1 is an isometric drawing showing a cast-in-place barrier 102 with a recessed LED lighting system 106 according to the present invention. LED lighting element 106 includes a plurality of LEDs aligned in an elongated configuration. Barrier 102 has a recessed area 104 into which lighting element 106 is placed. Power connection 110 provides power to lighting element 106 . Junction box 108 is cast in place in barrier 102 .
[0024] The LED luminaire 106 is mounted vertically and is recessed into the barrier 102 . The aiming of the luminaire provides light grazing on the barrier surface.
[0025] The vertically or near vertically mounted LED luminaire 106 provides uni-directional light along the barrier face. Since the luminaire is integrated into the barrier 102 , it does not cause a hazardous projection and does not compromise the crash function of the barrier.
[0026] The present roadside lighting system accentuates the roadway shoulder and barrier 102 by providing both beam and field contributions of the photometric distribution. The beam contribution of the LED system highlights obstacles such as the crash barrier 102 . The field contribution of the LED system spills light onto the roadway shoulder or other target. Disabled motorists, for example, become more visible to oncoming traffic and very little light will escape (minimize light trespass and pollution) from the roadway structures.
[0027] The low energy use and long lamp life of LED systems 106 reduce maintenance and operating costs.
[0028] FIG. 2 is an isometric drawing showing a discrete crash barrier 202 having a recessed LED lighting system 206 according to the present invention. This barrier lighting system is similar to that shown in FIG. 1 , in that barrier 202 includes a recessed area 204 , into which LED element 206 is placed. LED element 206 is oriented vertically, and provides a horizontal sheet of light across barrier 202 . In this example, barrier 202 is a Type 7 crash barrier, and includes a snow fence post 208 .
[0029] FIG. 3 is a photograph of a barrier lighting system according to the present invention, in use on a roadway at night. A demonstration of the LED barrier illumination method was performed in December 2003. In co-operation with the Colorado Department of Transportation an unused ramp along the Denver metro stretch of Interstate 25 was fitted with temporarily mounted LED strips. A commercially available LED 24 inch strip luminaire was modified to include only white LEDs. In addition, only 12 inches (continuous length) of the strip was illuminated. The modified LED strips were mounted vertically on the barriers to provide horizontal lighting in the direction of travel. The demonstration barrier lighting was set at 80 feet; each unit cast light along the barrier for approximately 60 feet. The guidance and illumination achieved by the LED system are demonstrated in FIG. 3 . The arrows indicate the light cast by several of the LED illumination units.
[0030] FIGS. 4-1 through 4 - 5 (prior art) show electrical and lighting details for several conventional roadway lighting systems, called luminaires, from the Colorado Department of Transportation. FIG. 4-1 is a side view of a luminaire attached under a bridge. FIG. 4-2A is a plan view of the electrical splice block for the luminaire. FIG. 4-2B is a section view of the splice block of FIG. 4-2A , with its cover removed. FIG. 4-3 is a side cutaway view of the buried electrical cable used to power the luminaire. FIG. 4-4 is a side cutaway schematic view of the wiring within a pole foundation. FIG. 4-5A is a plan view of a barrier luminaire. FIG. 4-5B is an elevation drawing of the barrier luminaire of FIG. 4-5A , and FIG. 4-5C is a section view of the barrier of FIGS. 4-5A and 4 - 5 B.
[0031] It will be appreciated by one versed in the art that there are many possible variations on these designs, but all are typified by LED lighting systems installed recessed areas of roadside barriers which provide a generally horizontal sheet of light across the barrier. Some known and anticipated variations are described below:
[0032] Variations include mounting the LED luminaire in a snow fence, guardrail or other roadside structure, a bollard, a bridge footing, or a tunnel wall. Barriers are made from a variety of geometries. Deployment of the LED lighting system is compatible with most conceivable barrier geometries.
[0033] The LED luminaries can be connected to electrical power supplies or operated from a portable power supply such as generator, fuel cell, or battery storage. In addition, alternative renewable supply such as photovoltaic assemblies can also be used as the power source.
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A system for lighting roadways utilizes LED lighting systems recessed into roadside barriers. The LED lighting element includes a number of LEDs fixed in an elongated formation. The LED lighting element is inserted into the barrier's recessed area in a generally vertical orientation. This results in the LED lighting system generating a horizontal sheet of light along the barrier.
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This application is a continuation in part of application Ser. No. 452,255, filed Dec. 22, 1982 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to sidewall coring tools. In determining the physical properties of subterranean formations, it is of great assistance to have what is commonly called cores. A core is typically a cylindrical piece of rock which has been cut from the underground formation and can vary in size and length. One type of core cutter is a type that can be used to cut the cores from the sidewall of a borehole after the borehole has already been drilled. Such a sidewall coring tool is described in U.S. Pat. No. 4,354,558 entitled, "Apparatus and Method for Drilling into the Sidewall of a Drill Hole," issued Oct. 19, 1982, with Alfred H. Jageler, Robert A. Broding and Lauren G. Kilmer as inventors. In that invention, a core barrel having a core cutting bit on the end thereof is pushed against the formation at the same time that the core barrel is rotated so that a core is cut and enters the core barrel. The present invention relates to system for retaining the core in the core barrel once the core is cut.
BRIEF DESCRIPTION OF THE INVENTION
This invention relates to an apparatus for use in cutting a sidewall core in a borehole and includes a hollow core barrel with a hollow core cutting bit attached to the end thereof. Means are provided to rotate the core cutting bit and core barrel and to drive the core cutting bit against the interior face of the borehole. In a preferred embodiment of my invention, a groove is cut circumferentially in the inside of the core barrel at the core cutting bit end and a core retaining sleeve is inserted therein. The core retaining sleeve is constructed of a material having elastic properties and is of a size and shape such that it will be expanded to grip and retain a core being cut and entering the core barrel and retaining sleeve, and is mounted such that the core retainer sleeve does not rotate as the core barrel and core cutting bit rotates for cutting the core. This is accomplished by designing the core retaining sleeve with a flange that has external dimensions smaller than the internal dimensions of the groove in the core barrel but with exterior dimensions which are large enough that the flange is not forced out of the groove during the cutting of a core, and such that the exterior dimensions of the core retaining sleeve with a core extending therein are smaller than the internal dimensions of the core barrel. The flange is reinforced with a metal ring as an aid in maintaining the flange in the groove during the cutting of a core.
A better understanding of the invention may be had from the following description taken in conjunction with the drawing.
BRIEF DESCRIPTIONS OF THE DRAWINGS
FIG. 1 is the schematic side view of a core barrel and a core cutting bit.
FIG. 2 is an isometric view of the core bit having an internal ring groove.
FIG. 3 shows a steel core retaining ring.
FIG. 4 is a schematic side view of a core barrel and core cutting head useful in the present invention.
FIG. 5 is an isometric view of the core retaining sleeve in the present invention.
FIG. 6 is a schematic side view of a core retaining sleeve of FIG. 5 in position inside the core barrel and core cutting head of FIG. 4.
FIG. 7 is an isometric view of the core retaining sleeve of FIG. 5 in position inside the core barrel and core cutting head of FIG. 4, expanded over a partially cut core.
FIG. 8 illustrates a metal retaining ring for use in the core retaining sleeve of FIG. 5.
DETAILED DESCRIPTION
FIG. 1 illustrates a core barrel 10 with core cutting bit 12 which is used in the prior art core cutting methods. It has an internal groove 14 which is shown more clearly in FIG. 2, which is an isometric view of the core cutting bit. A steel core catcher ring 16, illustrated in FIG. 3, is insertable into groove 14 of the core cutting bit, but not in such tight contact so that the core catcher ring will rotate with rotation of the core cutting head. The ring is situated such that as the core is cut by the core cutting bit moving into the rock, the cored section is inserted into the ring. The internal diameter of the ring is slightly smaller than the internal diameter of the core barrel. The ring 16, being split, expands and attaches itself to the core. The barrel revolves around the ring as the coring operation continues, thus, the ring does not rotate but merely slides along the exterior surface of the cut core.
The core retaining sleeve of this invention is particularly useful in the case of cutting cores from both fractured rock and unconsolidated rock, such as oil sands or chalks, where the cores can crumble during the cutting and then drop out of the end of the core barrel when the core barrel is retracted for core recovery. Attention will now be directed to the present invention. A core retaining sleeve in the form of a truncated cone 20 having a flange 22 at one end with a circumferential groove 34 on the interior rim of the flange is illustrated in FIG. 5. This core retaining sleeve can be made from a rubber or other resilient materials having elastic properties, such as Neoprene. It is a requirement that the material be such that it will not be damaged by the fluids which may be encountered in the drill hole. A core barrel 28 with a core cutting bit 26 attached to a core cutting head 18 is illustrated in FIG. 4. The flange 22 rides in circumferential groove 24 cut inside the core cutting head 18 near the core cutting bit end of the core cutting head, shown in FIG. 4, in such a way that during the cutting of a core when the core retaining sleeve is gripping the stationary core, it is not rotated by the rotation of the core cutting head and core cutting bit. It is felt that rotation of the core retaining sleeve around the core would expose the core to forces which would tend to crumble fractured and/or unconsolidated rock cores inside the core retaining sleeve and thus cause them to drop out of the core retaining sleeve when the core barrel is retracted for core recovery. The core retaining sleeve 20 in place inside the core barrel 28 and core cutting head 18 is shown in FIG. 6. As shown in FIG. 6 and FIG. 7, the inside diameter of the core barrel 36, the core cutting head 18 and the core cutting bit 26, is sufficiently large to allow for expansion of the core retaining sleeve 20 over the core as the core enters into the core barrel 36, such that the core retaining sleeve 20 does not contact the interior wall of the core barrel. As is shown in FIG. 7, the core retaining sleeve 20 expands over the cut core 30 as it enters the core barrel. The rubber flange 22 is reinforced by a metal ring 32, illustrated in FIG. 8, set inside circumferential groove 34 in flange 22 of the core retaining sleeve 20. The purpose of this metal ring is to prevent the flange from deforming under the forces generated as the core is inserted into the core retaining sleeve, and thus, cause the flange to remain in place in circumferential groove 24 inside the core cutting head as the core is inserted into the core retaining sleeve. The internal diameter of the metal ring is such that it does not damage a core extending into the core retaining sleeve.
As the leading edge of the core penetrates the core bit 26, the core retaining sleeve 20 begins to expand over the core end and with continued penetration of the core, the core retaining sleeve expands so that its inside diameter is the same as the outside diameter of the core. This results in the core retaining sleeve forming a tight sleeve around the core. In the case of cores cut from fractured and/or unconsolidated formations, this sleeve aids the core in retaining its shape and preventing crumbling of the core during the cutting. The lack of rotation of the core retaining sleeve is important since a rotation of the core retaining sleeve around the core would expose the core to forces which would tend to crumble it inside the core retaining sleeve.
The core retaining sleeve just described in this invention has been implemented and tested and was made of Neoprene.
While the above invention has been described in detail, various modifications can be made thereto without departing from the spirit or scope of the invention.
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A hollow truncated cone made from material with elastic properties which expands around a core being cut from the sidewall of a borehole drilled in the earth with a core cutting means rigidly connected to a core barrel. The hollow truncated core is held in position inside the core barrel such that it does not rotate with the core cutting means during the cutting of a core.
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[0001] This application is a Continuation-in-Part of U.S. patent application Ser. No. 09/684,057, filed Oct. 6, 2000, which claims priority to Sweden Application Ser. No. 9903637-8, filed Oct. 8, 1999. The present application also claims priority to EPO Application No. 01850013.4, filed Jan. 17, 2001. The above applications are incorporated herein by specific reference.
BACKGROUND OF THE INVENTION
[0002] 1. The Field of the Invention
[0003] The present invention relates to methods, apparatuses and a system in connection with pushing of packet data from an originator to a wireless communication station.
[0004] 2. Background and Brief Summary of the Invention
[0005] Today, different kind of digital radio communications networks that support packet data transfer are being evolved. This means that mobile users having access to these radio communication networks are provided with the possibility to communicate packet data with different packet data networks, such as with the Internet, but also with corporate intranets and X.25 networks and the like. Thus, the digital radio, or wireless, communication network will be a wireless extension of, for example, the Internet and existing X.25 networks. Subscribers to such a radio communication network, i.e., the mobile users, will be able to benefit from most of the applications designed for these data packet protocols, such as Web browsing and exchange of e-mails etc., from their wireless equipment with which they access the wireless communication networks. Furthermore, a number of new mobile data services are currently being developed which will make use of these packet data transfer capabilities, while the performance of existing mobile data services will be improved.
[0006] Many of the new and existing mobile data services will make use of the possibility to push data to mobile users. Typically, to push data to a user means that a push server of a system or network automatically provides the user with some kind of information, i.e., the transfer of information is performed on the initiative of the push server. Often this information is of the kind which is desired by the user, and therefore defined by a set of criteria in order to meet the desires of the user, e.g., information to which the user subscribes. However, since there are no standardized mechanism for preventing certain information to be pushed, in practice, any server may push any information to any user.
[0007] The technology of pushing information is today perhaps most widely used for pushing information to a stationary user, such as a user operating a computer connected to the Internet. However, with the rapid growth of mobile communications, in combination with the flexibility of being able to be reached by pushed information at any location, the possibility of receiving pushed information from a push server will become more and more interesting for users that are connected to wireless communication networks.
[0008] One of the most important grounds for the development described above is, besides the introduction of packet data transmissions to/from the wireless communication stations operated by the mobile users, the technology enhancements of the radio communications networks, such as the cellular radio communications networks, which provide higher and higher bandwidths for these packet data transmissions. Examples of wireless communication network with higher bandwidths and with support for packet data transfer to the wireless terminal of a mobile user are PDC-P networks (Pacific Digital Cellular), which in Japan provides the existing I-mode service, GSM networks (Global System for Mobile Communications) providing GPRS services (General Packet Radio Service), systems using radio networks based on EDGE technology (Enhanced Data Rates for GSM and TDMA/136 Evolution) or on WCDMA technology (Wideband Code Division Multiple Access), or any other forthcoming new generation of wireless communication networks which are known as UMTS networks (Universal Mobile Telephony Standard), or 3G networks, and which are based on the broadband radio networks WCDMA or cdma2000.
[0009] The pushing of packet data to a mobile user corresponds to a process in which the wireless communication network initiates the packet data transfer to the user's wireless communication station, wherein the packet data being transferred most often is received by the wireless communication network from an external source, i.e., a push server on an external network which is operatively connected to the wireless communication network. When pushing information to a wireless communication station there are three important requirements that have to be met in order for a wireless communication network to be able to initiate the packet data transfer to the wireless station. These requirements are that (1) the wireless station has been switched on; (2) the wireless station has identified itself to those parts of the wireless communication network that provides the packet data service; and that (3) a Packet Data Protocol (PDP) address has been allocated to the wireless station.
[0010] After the requirements above have been met, measures are taken by the wireless network for initializing and activating a packet data service to the wireless station, measures that are well known in the art. After activation of the packet data service, packet data addressed to the PDP address that has been allocated to a wireless station will be routed to that station. A PDP address can be allocated to the station either as a static or a dynamic PDP address. Thus, the PDP address to be used by a server wishing to push data to a mobile communication station, i.e., to transfer data without the station having specifically requested the data, is either a permanent (static) or a temporary (dynamic) address allocated to that station.
[0011] The PDP address, irrespective of whether it is static or dynamic, needs to be known to a server that wishes to transfer packet data to the station. The PDP address can become known to the server by making an inquiry to the appropriate repository, possibly different repositories depending on whether static or dynamic addresses are used, in the operator's wireless communication network.
[0012] In U.S. patent application Ser. No. 09/684,057, filed on Oct. 6, 2000, and incorporated herein by reference, a number of drawbacks related to the above described technique of inquiring for a mobile users PDP address are discussed. These drawbacks relate to the consequences of such things as: signaling load against the repository storing the PDP addresses; a change of the PDP address allocated to a specific mobile user from time to time; and the routing of PDP address requests to repositories.
[0013] The solution, according to the disclosure of the above identified patent application, is that a networks server, that wants to transfer packet data to a wireless communication station via a wireless communication network, requests that the wireless station sets up a Packet Data Protocol connection with the server. The request is accomplished by sending a message to the station, via a message service provided by the wireless network, using a subscriber's unique user identification number (such as a MSISDN number). In reply to the received message, which includes the packet data network address of the requesting server, the wireless station identifies itself to the packet data service part of the wireless network, if not already identified, activates a provided packet data service, if not already activated, and establishes a PDP connection with the requesting server. Using this PDP connection, the server may transfer packet data to the wireless communication station. This solution furthermore enables packet data to be transferred, or pushed, to a wireless station regardless of which current state the wireless station is in with respect to the packet data service of the wireless network.
[0014] When a packet switched connection, rather than a circuit switched connection, is used for transferring data to/from a user's wireless station, which for example is the case when introducing GPRS in a GSM system, it will be possible for the mobile user to be constantly connected not only to the wireless network, but also to the Internet or some other packet data network via the wireless network and an interconnecting gateway. As the mobile user is constantly connected, the user will be charged for the actual bandwidth he uses. This means that the mobile user will be charged for each packet transmitted or received by the user, rather than for the time duration of the data transfer. Thus, a subscriber will be charged for any information received as packet data, regardless of which source that transfers, or pushes, the packet data to the subscriber.
[0015] The above described solution provided by identified U.S. patent application Ser. No. 09/684,057 allows any network server to transfer a packet data network address to a subscriber by addressing the subscriber's unique user identification number. In this respect it would be desirable that the mobile user more easily could control to which network server he initiates a PDP connection. Moreover, it would be preferred that the mobile user could perform this control in real-time, thus enabling the mobile user to make a decision whether or not to establish a PDP connection at the particular moment when a server wishes to transfer packet data to the mobile user. A drawback with U.S. patent application Ser. No. 09/684,057 is that the above described solution does not include any satisfactory means for enabling a mobile user to perform such a desired control of PDP connection establishment, and thus, of information transfer from any network server wishing to transmit data to the mobile user. Thus, it does not provide a satisfactory scheme for preventing that a mobile user receives non-desired information. Not only is reception of non-desired information time consuming and frustrating for the mobile user, it is also costly since the mobile user have to pay for the received packet data over his subscription bill from the operator.
[0016] The drawbacks described above regarding the reception of non-desired information from any network server, and the additional drawback of being charged by an operator for such information, are also present in any situation where a network server knows the packet data network address of the user in advance and uses this address for establishing a packet data session with the user's wireless station.
[0017] An object of the present invention is to overcome at least one of the drawbacks described above that are present in connection with pushing packet data, i.e., transmission of packet data on an originator's own initiative, from an originator to a mobile user in a wireless communication network.
[0018] According to the present invention, said object is achieved by methods, a computer-readable medium, a wireless communication station and a system having the features as defined in the appended claims and representing different aspects of the invention.
[0019] According to the invention, when a wireless communication station from an originator of information receives the originator's network address, the wireless station acquires an identity corresponding to the received network address. This identity is used as basis when the wireless station determines if packet data reception from the originator is desired. If such reception is desired, the wireless station establishes a packet data session with the originator. Using this packet data session, the originator is able to transfer, or push, packet data to the wireless station.
[0020] Thus, according to the invention, pushing of packet data from an originator to a wireless communication station is only facilitated if it is determined by the wireless station that reception of packet data from the originator is desired. Since the wireless station will receive any originator's network address and then decide whether or not to facilitate reception of packet data based on a corresponding identity only, any originator with the ability to transfer its network address to the wireless station will have the potential ability to push packet data to the wireless station. Of course, provided that the originator has access to a packet data network which is operatively connected to the wireless communication network. However, such pushing of packet data can only be effectuated if the user of the wireless station chooses to facilitate reception of the pushed packet data.
[0021] Furthermore, the invention enables a user of a wireless station to control the reception of pushed packet data without requiring that the user, or its wireless station, has an established relationship with any potential originator providing pushed packet data, or that the wireless station has been particularly configured with respect to any potential originator, since such control solely is based on the identity of the originator. Moreover, the user is able to perform this control in real-time. For example, a user may choose to receive pushed packet data from an originator known to have interesting information relating to a geographical region, or from an originator which the user only sometimes wants information from in dependence upon, e.g., his mood or his available time to read or otherwise perceive the information.
[0022] According to the invention, the wireless station is responsible for acquiring the identity corresponding to a network address received from an originator. Thus, this is performed without any participation of the originator. This feature is advantageous since it adds a security aspect to the reception of pushed information. An originator will not be able to hide behind a false identity and he will have nothing to gain by transmitting a “stolen” or “borrowed” network address to the wireless station. Preferably, the identity corresponding to the received network address is acquired by using an address translation server. Since an address translation server typically is designed to regularly check what identity that corresponds to what network address, and to store these relationships in some kind of repository, the address translation server will upon request indicate the identity that currently is associated with a particular network address.
[0023] Moreover, since the packet data session used for the information transfer from the network server is established by the wireless communication station, there is no need to beforehand provide any network server with the network address of the wireless communication station. An advantage with this, among others, is that a network server can not establish a session to the wireless communication station in order to transfer, or push, information, possibly non-desired, to the wireless station.
[0024] A further advantage provided by the establishment of the packet data session from the wireless station, is that the originator does not generate any signaling load against any repository in the wireless network storing packet data network addresses, something which otherwise can be a heavy burden on the repository when numerous originators, or servers, are trying to acquire packet network addresses to wireless stations connected to the wireless network. Furthermore, if dynamic packet data network addresses are used by the wireless network, which most often is the case, the burden will be even heavier since the network address allocated to a specific wireless station will change from time to time. Moreover, when a wireless station is roaming between different wireless networks of different operators, the problem of determining to which operator's repository a server's requests for a packet data network addresses should be routed is avoided.
[0025] According to an exemplifying embodiment, a user is provided with the ability to control reception of pushed packet data in real-time by having the wireless station display the identity to the user, and then accept a user input in response thereto. In response to a confirmation, the wireless station effectuates an establishment of a packet data session with the originator. However, if the user inputs a rejection, a packet data session is not established, and reception of pushed packet data is thereby not facilitated.
[0026] Advantageously, the network addresses received by the wireless station is an Internet Protocol (IP) addresses. In this case the address translation server is preferably a DNS server (Domain Name System) which upon reception of an IP address returns a server host name.
[0027] According to an embodiment of the invention, the wireless station receives the originators network address in a short message provided to the wireless station by a short message service. The establishment of a packet data session with the originating server is either made based on this network address, or, via the address translation server, based on the corresponding identity of the originator. Preferably, an application executing in the wireless communication station, and controlling its operation, is responsible for the establishment of the packet data session. An originator is typically connected to a packet data network which is operatively connected to the wireless communication network. However, an originator may also be directly connected to the wireless communication network.
[0028] In an embodiment, use is made of an originator identification code. By verifying that a server, with which a packet data session is established for reception of packet data, uses the same identification code as the originator of a received network address, yet another security level is added.
[0029] It is to be understood that what is meant by the expression wireless communication station in this document, sometimes herein referred to only as wireless station, is either a stand-alone RF (Radio Frequency) transceiver having processing capabilities and displaying means, such as a mobile telephone or a hand-held PDA (Personal Digital Assistant), or, a RF transceiver together with any kind of portable or stationary equipment having processing capabilities, such as a portable laptop computer or a stationary personal computer, wherein the RF transceiver is arranged in communication with the portable or stationary equipment.
[0030] Even though the following description of an exemplifying embodiment will refer to a GSM network providing a GPRS service and an SMS-C (Short Message Service Center) providing a short message service, it is to be understood by those skilled in the art that the invention is not limited to these systems. The invention is advantageously applied to any wireless communication network that provides packet data transmissions to its connected users and that has an associated message service for transmitting short messages to the users. Such wireless communication networks have been exemplified in the background part of this application.
[0031] These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In order that the manner in which the above recited and other advantages and features of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0033] [0033]FIG. 1 schematically shows an exemplifying overall system environment in which an embodiment of the invention is included and operable; and
[0034] [0034]FIG. 2 is a flow chart of an embodiment of a method according to the invention which is practiced by a wireless communication station.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] With reference to FIG. 1, an exemplifying embodiment of the invention will know be described in greater detail. FIG. 1 shows a wireless communication network 10 , a wireless communication station 20 , a node 30 for generating short messages for transmission to wireless communication stations, an address translation server 40 , and an originator in the form of a network server 50 operatively connected to the wireless communication network 10 . The wireless communication network is exemplified with a GSM network (Global System for Mobile Communication) and the wireless communication station with a GPRS mobile station. The packet data transferring capabilities of the GSM network 10 is provided by the GPRS service (General Packet Radio Service). GPRS being a standardization from the European Telecommunications Standard Institute (ETSI) on packet data in GSM systems. The node for generating short messages is exemplified with a SMS-C (Short Message Service Center) and the address translation server with a DNS server (Domain Name System). The network server 50 could be any server connected to the Internet or to a corporate Intranet to which the wireless communication network 10 is operatively connected by means of an appropriate gateway (not shown).
[0036] The architecture and operation of a GSM Network providing a GPRS service, as well as the standardization thereof, should be well known to persons skilled in the art. For this reason, only those features or aspects of GSM and GPRS that are of direct relevance to this described embodiment of the invention will be described herein.
[0037] A GSM network 10 which includes a GPRS service for handling packet data traffic is equipped with a Serving GPRS Support Node (SGSN) (not shown) and a Gateway GPRS Support Node (GGSN) (not shown). The SGSN is the node within the GSM infrastructure that sends and receives packet data to and from a wireless GPRS mobile station 20 via a Base Station System (not shown). The GPRS mobile station 20 communicates with the Base Station System over an air interface in accordance with the standardization of GSM and GPRS. The SGSN also transfers packets between the GPRS station 20 and the GGSN. Furthermore, the SGSN handles PDP contexts (Packet Data Protocol) for connections with any server in any external packet data network, such as with the network server 50 which is operatively connected to the GSM network 10 . The GGSN, which is connected to the SGSN, is the gateway of the GSM/GPRS system to external packet data networks and routes packets between the SGSN and an external packet data network, e.g., the Internet or an corporate Intranet. For more information about GPRS, reference is made to ETSI standardization documents EN 301 113 V6.1.1 (1998-11) and Draft ETSI EN 301 344 V6.4.0 (1999-08), both documents which are incorporated herein by reference.
[0038] Furthermore, the architecture and operation of the SMS-C and the DNS server are well known to persons with ordinary skills in the art, thus, only features of direct relevance to the present embodiment will be described herein.
[0039] The wireless communication station of the present invention, i.e., the GPRS mobile station 20 in the embodiment of FIG. 1, includes a state of the art microprocessor 21 , a main memory 22 implemented by read only memory (ROM) and/or random access memory (RAM) or equivalents thereof, Input/output circuitry, such as a display 26 and a keyboard/keypad 27 , for communicating with a user, interface circuitry 23 in the form of transmitting/receiving radio frequency circuitry for communicating with the GSM network via an antenna 25 and the air interface, a bus 24 interconnecting the elements of the GPRS mobile station, as well as other appropriate components. Of these elements, at least some are controlled or otherwise designed to facilitate the practice of the method of the invention.
[0040] The microprocessor 21 executes appropriate computer-executable components stored in the main memory 22 , thus controlling the elements and the overall wireless communication station/GPRS mobile station 20 to function in accordance with the method of the invention. Alternatively, these computer-executable components are stored on a pre-recorded disk, in a pre-programmed memory device, or any other computer-readable medium being separate from the wireless communication station 20 . When the wireless communication station 20 and its included microprocessor 21 is provided with access to this computer-readable medium, its stored computer-executable components will direct the microprocessor 21 to control the overall wireless communication station 20 to function in accordance with the method of the invention.
[0041] The operation of the wireless communication station/GPRS mobile station 20 will be more fully understood from the description below and from the description of the flow chart shown in FIG. 2.
[0042] The operation of the overall system and of the wireless communication station/GPRS mobile station in FIG. 1 in accordance with the embodiment will now be described in a step by step fashion, wherein each step has a reference numeral in FIG. 1. The described operation is started when the originator, i.e., the network server or push server 50 , wants to push packet data over a TCP/IP connection to a GPRS subscriber operating a GPRS mobile station 20 .
[0043] 1. In step 1 the push server 50 connects to the SMS-C 30 and submits a request that an SMS message (Short Message Service) should be generated and transmitted to a GPRS subscriber having a particular MSISDN number (Mobile Station Integrated Services Digital Network) in accordance with the numbering plan used. This is performed over a transport protocol, such as TCP/IP or X25, in accordance with techniques that are well known to persons skilled in the art. The push server includes its own network address, i.e., its Internet Protocol (IP) address if the push server is connected to the Internet or an Intranet, in the submitted request. The push server 50 also generates an identification code which is included in the submitted request as an originator identification code. Furthermore, a port number to be used when setting up a TCP/IP-based connection towards the server 50 is included.
[0044] 2. In step 2 the SMS-C 30 transmits the generated SMS message with the push server's 50 IP address and its generated originator identification code to the GPRS mobile station 20 . The transmission is performed through the GSM/GPRS network 10 over a GSM signaling channel or on a GPRS traffic channel in accordance with state of the art techniques.
[0045] 3. In step 3 , an application already executing in the GPRS mobile station 20 , or, which is started when the SMS message is received, extracts the payload of the SMS message. The SMS message could e.g., include an activation code, and if this code corresponds to a predefined code which is accepted by the application, the application processing proceeds, otherwise the application processing is stopped. Thus, if no activation code is found, the SMS message is treated in the usual way, which is outside the scope of the present invention. If the activation code is present, the application extracts the payload of the SMS message, i.e., the received IP address, port number and originator identification code. The received originator identification code is saved and a TCP/IP connection is set up towards the DNS server 40 . This TCP/IP connection is preferably set up in accordance with the GPRS connection phase described below. The IP address received in the payload of the SMS message is then sent to the DNS server 40 over the established TCP/IP connection.
[0046] 4. In step 4 the DNS server 40 looks up the IP address to find the corresponding identity, in this case a corresponding server host name. When found, the matching server host name is transmitted back to the GPRS station 20 over the TCP/IP connection. Thus, the GPRS station 20 is provided with the host name of the server 50 wishing to push information to it.
[0047] 5. In step 5 the application is to determine whether or not packet data reception from push server 50 is desired. This is performed by displaying the host name of server 50 received from the DNS server 40 to the user on the display 26 associated with the GPRS station 20 . The application then waits for the user to input a response using the keypad 27 . When viewing the displayed host name, the user decides whether or not he wants to receive pushed packet data from the particular server. If the user inputs “yes”, this indicates to the application that reception of packet data is confirmed, i.e., desired by the user. A “no” indicates that reception of packet data from push server 50 at this moment, and for some reason, is rejected. In the latter case, the execution of the application is stopped. If reception is confirmed, the application processing then continues to the GPRS connection phase.
[0048] As previously described in the background section, when pushing information to a wireless communication station, there are three requirements that have to be met in order for a wireless communication network to be able to initiate the packet data transfer to the wireless station. These requirements, which are part of the GPRS connection phase, include that (1) the wireless station has been switched on; (2) the wireless station has identified itself to those parts of the wireless communication network that provides the packet data service; and that (3) a Packet Data Protocol (PDP) address has been allocated to the wireless station.
[0049] In a GSM/GPRS network 10 , after the requirements above have been met, measures are taken by the GSM/GPRS network for initializing and activating a packet data service to the wireless GPRS station 20 , measures of the GPRS connection phase that are well known in the art. After activation of the packet data service, packet data addressed to the PDP address that has been allocated to a GPRS station 20 will be routed to that station. As described in the background section, the PDP address allocated to the GPRS station 20 is either a permanent (static) or a temporary (dynamic) address allocated to that station.
[0050] Thus, in the GPRS connection phase the application identifies the GPRS station 20 for the packet data service part of the GSM/GPRS network 10 , if it is not already identified. This corresponds to checking whether the GPRS station 20 is GPRS attached or not. If the GPRS station is not attached, the application performs a GPRS attach. The GPRS attach is preferably performed in accordance with standard procedure, see for example Draft ETSI EN 301 344 V6.4.0 (1999-08), chapter 6.2. The GPRS application then checks if the GPRS station 20 has a valid IP-address (i.e., if it has a working TCP/IP connection). If not, the application requests the GSM/GPRS network 10 to activate a packet data service to be used by the GPRS station 20 , i.e., it initiates the performance of a GPRS PDP Context Activation. The GPRS application then either receives a dynamically allocated IP-address from the GSM/GPRS network 10 or from a Radius server (not shown) via the GSM/GPRS network. The GPRS PDP Context Activation and the transfer of a dynamic IP-address are preferably performed in accordance with standard procedure, see for example TS 101 348 V6.3.0 (1998-10), chapter 11.2.1.2. Of course, the GPRS application could alternatively already have a static IP address allocated to it when initiating the GPRS PDP Context Activation. The application of the GPRS station 20 then initiates establishment of a TCP/IP connection towards the IP-address and the port number received in the SMS message. The IP address and the port number designates the server 50 and a server application wishing to push packet data. Alternatively, when establishing the connection, the push server 50 is identified using the server host name received from the DNS server 40 .
[0051] 6. In step 6 the push server 50 recognizes that a TCP/IP connection has been set up from the GPRS station 20 to which it earlier initiated the transmission of an SMS message in order to accomplish the now established connection. This recognition is based on information which the GPRS station 20 has included in the response message, e.g., the MSISDN of the GPRS station 20 or a request code originally generated and included in the SMS message previously transmitted by the server 50 . The push server 50 responds by first transmitting the same originator identification code which it earlier transmitted in the SMS message to the GPRS station. This will enable the GPRS station to verify that the push server 50 to which a TCP/IP connection now is established is the same server as that which transmitted the original SMS message triggering the set-up of the connection. After transmission of the identification code the push server 50 start transmitting packet data with information to the GPRS station 20 .
[0052] In FIG. 2 a flow chart of the operation of a wireless communication station/GPRS mobile station and its included executing application is shown.
[0053] In step S 1 the mobile user enters the IP address of the DNS server 40 , which is stored in a memory 22 of the GPRS station 20 for later retrieval by an application executing in the GPRS station. Alternatively, this step S 1 relates to the actual loading of the application in the GPRS mobile station, which application already includes the IP address of the DNS server 40 .
[0054] In step S 2 the application of the GPRS station receives an SMS message from which payload it extracts an IP address, port number and an originator identification code. The application then in step S 3 establishes a TCP/IP connection with the DNS server using the pre-stored IP address. It then in step S 4 transmits the IP address received in the SMS message and requests the DNS server to perform an address translation. In response to the request, the application in step S 5 receives a host name from the DNS server.
[0055] In step S 6 the received host name is displayed on the display 26 for the user of the GPRS station. It then in step S 7 waits for a response from the user via the keypad 27 . If the application receives a rejection, the execution returns to step S 2 . If a confirmation is received, the execution continues to step S 8 .
[0056] In step S 8 the application establishes a TCP/IP connection with the originator of the IP address received in the SMS message, i.e., with the push server 50 . It then once again receives an originator identification code from the push server, this time in step S 9 over the TCP/IP connection, which code in step S 10 is matched against the identification code previously received in the SMS message. If no match is found, the execution returns to step S 2 . If a match is found, the execution continues to step S 11 , in which step packet data transmissions are accepted and received from the push server.
[0057] Although the invention has been described with reference to a specific exemplifying embodiment based on a GSM system providing a GPRS service, many different alterations, modifications and the like will become apparent for those skilled in the art. The described embodiments are therefore not intended to limit the scope of the invention, as defined by the appended claims. Instead, it is to be understood that the present invention is well suited for any wireless communication network that provides a packet data service to its connected wireless users.
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The present invention relates to methods, apparatuses and a system in connection with pushing of packet data from an originator to a wireless communication station 20. When a network address is received by the wireless station 20 from a server 50 wishing to push packet data to the wireless station, the corresponding identity is acquired by the wireless station. Based on this identity the wireless station determines if packet data reception from the originator is desired. If such reception is desired, the wireless station establishes a packet data session with the originator. Using this packet data session, the originator is able to transfer, or push, packet data to the wireless station. Thus, according to the invention, pushing of packet data from an originator to a wireless communication station is only facilitated if reception of packet data from that originator is desired, something which can be controlled in real-time.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a National Stage Application of PCT International Application No. PCT/FR2010/000349 (filed on May 6, 2010), under 35 U.S.C. §371, which claims priority to French Patent Application No. 0903037 (filed on Jun. 23, 2009) and French Patent Application No. 0902240 (filed on May 7, 2009), which are each hereby incorporated by reference in their respective entireties.
FIELD OF THE INVENTION
[0002] The invention relates to the field of immunology, namely the field of interaction between an antigen and an antibody. More specifically, the invention relates to the use of a synthetic antigen (TCSP), derived from a protein of the unicellular parasite Trypanosoma Cruzi , which is the cause of Chagas disease, for the detection of antibodies not related to Chagas disease, which make it possible to diagnose certain autoimmune diseases in a human patient.
BACKGROUND OF THE INVENTION
[0003] It is known that infectious agents can escape the immune system of a host by interfering with the normal maturation of an effective humoral immune response, and by directing induced antibodies against autoantigens. In addition, due to structural similarities between certain infectious antigens and self-antigens, it is thought that certain infectious agents are capable of triggering an autoimmune response in hosts that have a genetic predisposition.
[0004] Chagas disease is endemic in Latin America and South America, and is a major cause of morbidity and mortality in the countries where it flourishes. It is practically absent on other continents. Around 16 to 18 million people are infected, and around 50,000 patients die of it each year. It is the infection by the unicellular parasite Trypanosoma Cruzi ( T. cruzi ), a member of the Kinetoplastida order and the Trypanosomatidae family that induces Chagas disease in human beings; this protozoan parasite is transmitted by numerous hematophagous insects, and in particular by Triatominae (hematophagous plant bugs). Transmission takes place when the infectious forms of the parasite are deposited in an insect sting, when dejections of the vector insect come into contact with the blood or mucous membranes of the host. The vector insect thus releases infectious metacyclic trypomastigote forms that, by blood circulation, will colonize numerous cell types. The complex life cycle of the parasite enables it to escape the immune response of the host, without causing the death of the host. The parasite goes through an epimastigote step in the vector insect, a trypomastigote step in the blood of the host mammal, and an intracellular amastigote step: during this final step, the parasite multiplies by binary division. Another route of contamination is blood transfusion with contaminated blood; numerous screening methods have been developed (See, for example, EP Patent No. 0 976 763 and U.S. Pat. No. 6,458,922).
[0005] It is known that T. cruzi infects cardiac and skeletal muscle cells, glial cells and the cells of the mononuclear phagocyte system. After passive penetration in the host cell, the trimastigote form of the parasite is differentiated into the amastigote form; it actively divides, then the trypomastigote forms are released, thus causing a new cell invasion. Around 30% of patients with this disease develop severe clinical cardiomyopathy-type symptoms (See the article of K. Karratolios et al., “Inflammatory Cardiomyopathy”, published in 2006 in the review Hellenic Journal of Cardiology, vol. 47, p. 54-65, and the article of J. Burian et al., “Myocarditis: the immunologist's view on pathogenesis and treatment”, published in 2005 in the review Swiss Medical Weakly, vol. 135, p. 359-364); these cardiomyopathies may be acute or chronic.
[0006] Comparable cardiac conditions may be observed in patients infected by the human immunodeficiency virus (HIV) or other infectious agents outside of any Chagas disease context. Comparable cardiac conditions may also exist to a lesser extent in apparently healthy subjects; it is known (See, the article of F. Kierszenbaum, “Views on the autoimmunity hypothesis for Chagas disease pathogenesis”, published in 2003 in the review “FEMS Immunology and Medical Microbiology”, vol. 1545, p. 1-11, and the article of R. Jahns et al., “Pathological autoantibodies in cardiomyopathy”, published in September 2008 in the review Autoimmunity, vol. 41(6), p. 454-461) that these conditions result from autoimmune mechanisms of unknown origin. Indeed, autoimmune reactions can be observed in patients with cardiomyopathies without the precise origin, or the specificity of the antibodies, or especially of the immunogens involved, being known. No document describes a defined antigen structure, responsible for this autoimmunity and more specifically a T. cruzi (TCSP) antigen. Antibodies against receptors (adrenergic or cholinergic) have been described, but without any definition of their specificity with respect to the TCSP peptide; and in no way has the involvement of an antigen of the T. cruzi parasite outside of its natural context of Chagas disease been described.
[0007] It is known that each step of the life cycle of the T. cruzi parasite expresses specific antigen proteins, as described, for example, in the article of Hoft et al. (“Trypanosama cruzi Expresses Diverse Repetitive Protein Antigens”), published in July 1989 in the review Infection and Immunity, vol. 57 (7), p. 1959-1967). In the studies described in this publication, the authors screened a T. cruzi expression bank with human anti-serums and found cDNA that code for polypeptides containing repetitive units including 6 to 34 amino acids. The amino acid sequence of TCR70 (which is identical to TCR69) was strongly preserved, with only some occasional substitutions. Their frequent appearance in all of the isolated fractions and the diversity of these repetitive units suggest that they are involved in the circumvention of the destructive role of the immune system. Since these repetitive units are effective modulators of the immune system, it can be thought that other infectious agents use similar strategies, or even the same repetitive units.
[0008] The methods for screening antibodies directed against T. cruzi , which are used in blood banks (in particular in Brazil, where this screening is obligatory), include indirect immunofluorescence (IFA), indirect hemagglutination (IHA), and immunoenzymatic assay techniques (ELISA). Most of these assay kits, which are available on the market, use raw parasite extracts or sub-cellular fractions as antigen preparations. It was found that the parasite extracts react with serums of patients who have other diseases, such as leishmaniasis, the Trypanosoma rangeli infection, syphilis or rheumatoid fever. Consequently, the use of similar repetitive units by different pathogenic organisms complicates the diagnosis and treatment. In addition, a false positive response in the screening for Chagas diseases can lead to a false diagnosis that will be followed by a superfluous and/or ineffective treatment.
[0009] Consequently, there is an urgent need to be capable of detecting repetitive units that can be used by different pathogenic organisms. However, the prior art does not contain any documents showing or suggesting that the polypeptide motifs TCR70 identified in T. cruzi exist in other diseases unrelated to Chagas disease, or lead to autoimmune disorders. It has also not been shown or suggested in the prior art that these repetitive units can enable the development of reliable tools for the diagnosis and treatment or effective prevention of cardiac pathologies or autoimmune disorders associated or not with Chagas disease. There is therefore also a need to provide immunodiagnostic methods, which are preferably quick or capable of being used in the form of kits, for detecting pathogenic antibodies capable of binding specifically to the antigens expressed by T. cruzi . And finally, there are no methods for reducing the concentration of these pathogenic antibodies in the blood.
SUMMARY OF THE INVENTION
[0010] In accordance with the invention, the stated problems are solved by the use of antibodies that bind specifically to a peptide including the sequence: Ala-Ala-Ala-Pro-Ala-Lys-Ala-Ala-Ala-Ala-Pro-Ala-Lys-Thr-A la-Ala-Ala-Pro-Val (SEQ ID N o 1), and which are not induced in a host after its infection by T. cruzi . These antibodies as such represent the first subject matter of this invention.
[0011] The second subject matter of the invention is an antigen that binds specifically to the antibody according to the first subject matter, with the exception of the antigens that bind also to antibodies induced by T. cruzi and which are genetically coded by the T. cruzi parasite, i.e. with the exception of antigens including the sequence SEQ ID N o 1.
[0012] The third subject matter is the use of a peptide or a protein including the sequence: Ala-Ala-Pro-Ala-Lys-Ala (SEQ ID N o 2), and preferably the sequence: Ala-Ala-Ala-Pro-Ala-Lys-Ala (SEQ ID N o 3), and even more preferably the sequence SEQ ID N o 1, for the detection and/or precipitation of antibodies according to the first subject matter, insofar as the peptide or the protein has a specific activity with respect to the antibodies. In particular, the peptide or the protein can be a TCSP peptide or a variant of the TCSP peptide, insofar as the variant has a specific activity with respect to the antibodies according to the first subject matter of the invention.
[0013] The antibodies can bind to antigens of an infectious agent, an allergen and/or a self-antigen; the infectious agent can be a pathogenic agent, and the presence of the antibodies is then associated with an infectious or autoimmune disease. The pathogenic agent can also be selected from the group formed by prions, viruses, prokaryotes and eukaryotes that are unicellular or multicellular.
[0014] The infectious or autoimmune disease can be selected from the group formed by cardiomyopathy, myocarditis and systemic lupus erythematosus.
[0015] Another subject matter of the invention is a method for detecting antibodies in accordance with the first subject matter in a liquid sample, which method includes the following steps: (a) placing a biological sample, preferably a sample of body fluid and/or supernatant liquid of a cellular culture (“liquid sample”), in contact with a peptide or a protein including the sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3, or with a TCSP peptide or a variant of the TCSP peptide, insofar as the peptide or the protein has a specific activity with respect to the antibodies in accordance with the invention; and then (b) determining the bond of the antibody in accordance with the invention in the liquid sample with the peptide or the protein by means of one or more suitable markers, capable of determining the complex formed between the peptide or protein and the antibody in accordance with the invention.
[0016] The marker can be selected from the group consisting of chemiluminescence markers, agglutination markers, membrane markers, immunoenzymatic markers and radioactive markers.
[0017] Yet another subject matter of the invention is a kit or a device for implementing the method in accordance with the previous subject matter, including: (a) a determined amount of one or more peptides and/or proteins the sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3, and/or of a TCSP peptide or a variant of the TCSP peptide, insofar as the peptides or the proteins has a specific activity with respect to the antibodies in accordance with the first subject matter of the invention; (b) one or more suitable markers, capable of determining the complex formed between the peptide or protein and the antibody according to the first subject matter of the invention; (c) optionally, a solid support, preferably impregnated by the peptide or the protein.
[0018] The marker can be selected from the group consisting of chemiluminescence markers, agglutination markers, membrane markers, immunoenzymatic markers and radioactive markers.
[0019] Yet another subject matter is an immunodiagnostic method including a step of qualitative or quantitative detection of the antibodies according to the first subject matter by the use of a peptide or a protein including the sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3, or with a TCSP peptide or a variant of the TCSP peptide, insofar as the peptide or the protein has a specific activity with respect to the antibodies in accordance with the first subject matter of the invention.
[0020] Yet another subject matter is a method for reducing the concentration of antibodies in accordance with the first subject matter in a biological fluid sample, such as a blood sample, or in a biological fluid flow, such as a blood fluid, including a step of precipitation of the antibodies by means of a peptide or a protein including the sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3, or with a TCSP peptide or a variant of the TCSP peptide, insofar as the peptide or the protein has a specific activity with respect to the antibodies in accordance with the first subject matter of the invention.
[0021] It is also possible to use the TCSP peptide or variants thereof to obtain antibodies or fragments of antibodies having a bonding activity equivalent to the NCRA (Non-Cruzi-Related Antibody, i.e. an antibody not induced by T. cruzi ); this is yet another subject matter of the invention.
[0022] The peptides or proteins including one of the peptide sequences (SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3) can be used to identify or even isolate the immunogens that induce the NCRA antibodies. Methods for conducting computer searches for sequence homologies using advanced algorithms can serve as tools for identifying immunogenic candidates. The immunogenic candidates can be synthesized, then tested for their reactivities with biological samples suspected of containing NCRA. The use of a peptide or a protein including the sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3 or of a TCSP peptide or a variant of the TCSP peptide, insofar as the peptide or the protein has a specific activity with respect to the antibodies according to the first subject matter of the invention, for identifying or isolating a pathogenic agent that binds specifically to the NCRA or that is recognized specifically by NCRA, forms another subject matter of the present invention. This interaction is based on a homology between the pathogenic agent and the TCSP or the variant of the latter.
[0023] Yet another subject matter of the invention is represented by the use of a peptide or a protein including the sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3 or of a TCSP peptide or a variant of the TCSP peptide, insofar as the peptide or the protein has a specific activity with respect to the antibodies in accordance with the first subject matter of the invention, for obtaining antibodies or antibody fragments having a bonding activity equivalent to NCRA.
[0024] The final subject matter of the invention is a pharmaceutical preparation including antibodies or antibody fragments having a bonding activity equivalent to NCRA, a pharmaceutically acceptable injectable solution and optionally one or more carriers (such as polysorbate and/or saccharose) or additives, in which the antibodies or antibody fragments have been obtained either by a use in accordance with the third subject matter of the invention in a living organism, leading to the immunization of the organism against the TCSP peptide, or by screening using the TCSP on a bank of bacteriophages that express specific antibodies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 shows the distribution of the intensity of a signal associated with the presence of antibodies that bind specifically to the TCSP peptide, and which are not necessarily associated with a T. cruzi infection (these antibodies are called NCRA, Non-Cruzi-Related Antibodies). This data comes from an epidemiological trial involving a number N of patients belonging to four groups: DS=Healthy donors [French: donneurs sains] (i.e. blood donors monitored and selected, who therefore have a better health status than the average general population); HIV Africa: African patients with a positive response to an HIV virus screening; HIV Western: Western patient with a positive response to an HIV virus screening; Chagas: Patients infected by T. cruzi . The data contained in this table comes from ELISA-type assays. It is represented numerically in Tables 1 and 2.
[0026] FIG. 2 shows the results of an epidemiological study on 79 patients, namely the NCRA concentration as a function of time (in years) since the inclusion of the patients in the study.
DETAILED DESCRIPTION OF EMBODIMENTS
[0027] In the context of the invention, the following terms have a specific meaning. The term “Chagas disease” refers to a pathological state caused by infection with the Trypanosoma Cruzi parasite, via the parenteral route or not. The term “disease other than Chagas” refers to any pathological state not caused by the Trypanosoma Cruzi parasite, and which leads to increased reactivity of antibodies against the new antigen, referred to here as TCSP, defined hereinbelow.
[0028] By “amino acid,” it is meant natural and unnatural amino acids. “Natural” amino acids include the L form of amino acids that can be found in proteins of natural origin, i.e.: alanine (A), arginine (R), asparagine (N), aspartic acid (D), cysteine (C), glutamine (Q), glutamic acid (E), glycine (G), histidine (H), isoleucine (I), leucine (L), lysine (K), methionine (M), phenylalanine (F), proline (P), serine (S), threonine (T), tryptophane (W), tyrosine (Y) and valine (V).
[0029] “Unnatural” amino acids include the D form of natural amino acids, the homo forms of certain natural amino acids, such as: arginine, lysine, phenylalanine and serine, and the nor forms of leucine and valine. They also include other synthetic amino acids.
[0030] “Peptide compounds” include in particular peptides and polypeptides, including derivatives obtained for example by glycosylation, acetylation, phosphorylation, or reaction with fatty acids. This term also includes proteins and peptides of natural origin.
[0031] The term “antibody” includes polyclonal and monoclonal antibodies. The term “monoclonal antibody” refers to an antibody composition having a homogeneous population, regardless of the species, the origin and the method for obtaining said antibody. In addition, the term “antibody” includes human antibodies in which at least some of the immunoglobulin domains are present, such as antibody fragments and the so-called VHVL domains (Variable Heavy and Variable Light Chains), and mini-antibodies.
[0032] The term “NCRA” or “NCRA antibody” (Non-Cruzi-Related Antibodies) refers to antibodies that bind specifically to the TCSP antigen, and which are not induced in a host after its infection by T. cruzi.
[0033] The terms “TCSP” ( Trypanosoma Cruzi Synthetic Peptide), “TCSP antigen”, “TCSP peptide” or “TCSP protein” all refer to a new peptide as defined by the invention, which comprises an amino acid sequence that is also found in proteins TCR70 and TCR69, namely SEQ ID N o 1, defined below, which can be isolated in T. cruzi , and which acts as an antigen with NCRA, as well as all variants and functional equivalents, such as its linear or non-linear epitopes recognized by NCRA as defined above. The minimal structure of the epitope corresponds to SEQ ID N o 2, defined below.
[0034] The term “self-antigen” refers to an epitope present in an endogenous molecule of the host, and which can be recognized by the immune system of said host, in order to possibly trigger an immune response. This mechanism can lead to an “autoimmune disease”, defined here as a pathological state caused by an undesired immune response of a host against a self-antigen (also called self epitope).
[0035] The term “infectious agent” refers here to any agent, living or not, capable of triggering an immune response. More specifically, it refers to pathogenic agents, allergens and haptens. “Pathogenic agents” include in particular prions, viruses, prokaryotes and eukaryotes that are isolated or not. “Allergens” include all substances or molecules capable of spontaneously causing an immune response in a host when said host is exposed to said substances or molecules.
[0036] The term “biological fluid” refers to the body fluid of a living organism, such as a human patient, i.e. any fluid sampled from a patient, such as serum, plasma, total blood, urine, cerebrospinal fluid, saliva, or the supernatant liquid of a cell culture.
[0037] In accordance with the invention, the problem is solved by the use of a new antibody that reacts with a new antigen (TCSP), derived from a protein of a unicellular parasite causing Chagas disease, Trypanosome Cruzi ( T. cruzi ). The particularity of this invention lies in the specific recognition of the TCSP antigen by antibodies not related to the T. cruzi parasite (called NCRA antibodies), therefore not having been induced by said antigen. This heterologous recognition phenomena is explained by the structural mimicry of the TCSP antigen with another immunogen, endogenous or exogenous, having immunized the individual and induced the NCRA.
[0038] The peptide sequence of the TCSP antigen is derived from a protein known and present in the databases Swissprot, Uniprot and TrEMBL (Accession Q7M3W1). This protein is known as TCR69; it is similar to protein TCR70.
[0039] In accordance with the invention, the peptide sequence of the protein used to define the NCRA antibody, expressed in three-letter amino acid codes, is:
[0000]
(SEQ ID N o 1)
Ala-Ala-Ala-Pro-Ala-Lys-Ala-Ala-Ala-Ala-Pro-Ala-
Lys-Thr-Ala-Ala-Ala-Pro-Val.
[0040] The immunoreactive variants of this peptide are also included in the context of this invention, insofar as they have the same antigenic properties. The variants of a peptide sequence can be obtained, for example, by substitution of one or more amino acids by other chemical entities, on the condition that the bioactivity of the original sequence is preserved; they can also be obtained by addition of chemical compounds such as biotin or natural or synthetic polymers, such as polylysine or polysaccharide. All of these variants that preserve the bioactivity of the original sequences are covered by this invention.
[0041] These variants can in particular be constituted by the sequence:
[0000]
(SEQ ID N o 2)
Ala-Ala-Pro-Ala-Lys-Ala, and preferably the
sequence:
(SEQ ID N o 3)
Ala-Ala-Pro-Ala-Lys-Ala.
[0042] This sequence can be repeated one or more times, and during this repetition, the terminal unit (in the “C-terminal” sense) of alanine can be substituted by a threonine unit, as in SEQ ID N1. The peptides constituted by these sequences also have this same bioactivity and can be used in the context of this invention.
[0043] TCSP can be obtained by purification from the T. cruzi parasite protein extract, typically leading to proteins TCR69 or TCR70 (see the publication of Hoft et al., cited hereinabove), which have sequences SEQ ID N o 1, SEQ ID N o 2 and SEQ ID N o 3. TCSP and its variants can also result from chemical synthesis (for example, in accordance with the Merrifield method, which is well known to a person skilled in the art). They can also be obtained by molecular cloning technology, such as recombinant DNA, involving the protein expression in microbial expression systems after insertion of a nucleotide sequence coding for the sequence of the peptide, followed by culture, extraction and purification of the peptide of interest.
[0044] TCSP antigens and variants thereof cannot be used for screening for Chagas disease because they lead to false positive reactions. The inventors discovered that TCSP interacts specifically with NCRA. This means that TCSP comprises a specific peptide sequence, which is capable of binding to NCRA. This bond can be detected by any known method, such as chemiluminescence, agglutination methods, and immunoenzymatic or radioactive methods.
[0045] The biomarker antibody is present in biological fluids, and its presence is correlated with clinical symptoms in patients with cardiomyopathy, for example, subjects infected by HIV who have developed cardiac complications. This invention relates to the peptide sequence of TCSP as well as any structural analogue capable of binding to the same biomarker antibody and which are not necessarily induced by the T. cruzi parasite (NCRA). The invention also relates to an immunological assay method, for the detection and monitoring or myocarditis and cardiomyopathies in patients after an infection or autoimmune inflammation.
[0046] One embodiment of the invention is a method for determining, qualitatively or quantitatively, the NCRA concentrations in a biological sample, including the following steps: a) obtaining a biological sample, such as serum, plasma, total blood, urine, cerebrospinal fluid, saliva, a biopsy sample, or the supernatant liquid of a cell culture; and then b) determining the NCRA concentration in said biological sample.
[0047] The biological sample can be in liquid, gel or solid form. It can come from a patient or in vitro cultures.
[0048] The invention also relates to the monitoring of the treatment of cardiomyopathies, by determination of the NCRA concentration. Indeed, the method described above can also be applied to the estimation of the probability of fetal death caused by an in utero cardiac arrest, due to the presence of NCRA in pregnant women. Indeed, the transplacental passage of these antibodies can damage the cardiac cells during embryogenesis. Their effects are even more significant insofar as the cardiac tissue is primitive. In this method, a sample of a biological fluid of the patient, a pregnant woman, is obtained, and the NCRA concentration in this sample is determined.
[0049] In addition, the NCRA assay can lead to a therapeutic strategy in patients with cardiomyopathies or to the development of a vaccine against this disease. At present, the nature of the immunogen inducing the biomarker antibodies is not known; however, the TCSP sequence disclosed in this invention can lead to the characterization of the etiology of the disease, to the isolation of an infectious or non-infectious agent inducing said NCRA in human subjects not having been in contact with the T. cruzi parasite, and thus, contribute to the development of new therapeutic strategies.
[0050] As an example, antibodies or anti-TCSP antibody fragments can be designed so as to prevent, by competition, the binding of NCRA to their biological target site and thus inhibit their pathogenic effects. The design of such competitive antibodies is made possible by this discovery.
[0051] In addition, the longitudinal measurement (in the same patient over time) of NCRA can indicate a change in the cardiomyopathy and the efficacy of any treatment thereof. The subtraction of this same NCRA from the blood circulation, i.e., by immunoadsorption techniques, can reduce or even entirely suppress their pathogenic effects.
[0052] The invention is based on the surprising discovery of the antigenic properties of a protein isolated from the T. cruzi parasite in subjects who have never been in contact with this parasite. Indeed, the TCSP antigen has an exceptional “heterospecific” activity with NCRA, widespread in living human subjects outside of the endemic regions of the parasite. It clearly involves a peptide mimicry mechanism; these antibodies induce false positive reactions in a test screening for Chagas disease.
[0053] This mechanism enables the TCSP peptide to bind specifically to the NCRA directed against self-antigens or against infectious agents other than T. cruzi . Consequently, one embodiment of the invention is directed to the use the TCSP polypeptide or its immunoreactive variants, for the detection of NCRA. These NCRA antibodies can also bind to self-antigens, or to antigens of infectious organisms with more or less affinity and specificity than those of the bond with TCSP.
[0054] More specifically, this invention provides a polypeptide as described hereinabove, for identifying or isolating an infectious or non-infectious agent inducing antibodies that in turn can cause an autoimmune disease. The invention also provides a polypeptide as described above, in which said infectious agent is a virus or a microbe relatively widespread among human subjects apparently in good health, and largely widespread in particular in subjects infected by HIV, such as mycoplasms and other opportunistic infectious agents. The invention also makes it possible to use a polypeptide as described above, in which said autoimmune disease is chosen from those described in cardiac pathologies such as cardiomyopathies and myocarditis. In addition, the invention provides a method for detecting antibodies against the TCSP polypeptide, by placing the TCSP or a variant in contact with the NCRA present in a biological fluid sample, and the detection of the NCRA bonds in the biological sample by methods known to a person skilled in the art.
[0055] In addition, the invention provides an analysis method for the detection of antibodies against the TCSP polypeptide, including reagents or tools enabling the antigen-antibody bond to be detected by means of methods known to scientists in the field of immunoanalysis. In yet another embodiment of the invention, the TCSP polypeptide or its variants are used, insofar as the latter have a specific activity with respect to NCRA, to improve the specificity of serological screening analyses for Chagas disease. It is clear from the results shown in FIG. 1 that the NCRA, detected in screening tests, can have an origin other than an infection by the T. cruzi parasite. Consequently, the inhibition of these antibodies by the TCSP antigen can improve the specificity of Chagas disease diagnostic tests.
[0056] The immunoreactivity tests in this invention were performed by an ELISA (Enzyme-Linked Immunosorbent Assay) technique, known to a person skilled in the art. Any other technique, however, making it possible to detect or measure the antigen-antibody bond can also be applied to the invention, in particular in order to implement the new immunodiagnostic method that forms one of the subjects of the invention.
[0057] Another aspect of the invention is the therapeutic use of the TCSP peptide or its variants to obtain antibodies or antibody fragments having a bonding activity equivalent to NCRA. In this use, antibodies or antibody fragments are first prepared by immunization of a living organism (for example, animal) against the TCSP peptide. Then, a pharmaceutical preparation including these antibodies or antibody fragments, a pharmaceutically acceptable injectable solution and optionally adjuvants (such as polysorbate, saccharose) is prepared.
[0058] Then, this pharmaceutical preparation is administered (for example, injected) to a patient in order to compete with the pathogenic NCRA. Thus, the pathogenic NCRA concentration is reduced, and the clinical symptoms of the patient improve.
[0059] Yet another aspect of the invention is a method for reducing the concentration of antibodies in accordance with the invention in a biological fluid sample, and in particular a blood sample or in a blood flow, including a step of retaining the antibodies by means of a peptide or a protein including the sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3, or with a TCSP peptide or a TCSP peptide variant, insofar as said peptide or said protein has a specific activity with respect to the antibodies in accordance with the invention. This method can be implemented for the purpose of diagnosis, for the purpose of treatment of a quantity of biological fluid or for therapeutic purposes by plasmapheresis. It can be implemented statically or in a flow of the biological fluid. Preferably, it is implemented as an immunoadsorption method. In a typical embodiment, the biological fluid comes into contact with a solid support on which the peptide or the protein or the protein including sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3, or the TCSP peptide or a variant of the TCSP peptide is fixed. The antibodies, if present, then precipitate on this solid support and are removed from the biological fluid.
[0060] Another aspect of the invention is a pharmaceutical preparation including antibodies or antibody fragments having an activity equivalent to NCRA, a pharmaceutically acceptable injectable solution and optionally one or more adjuvants, such as polysorbate and/or saccharose. These antibodies or antibody fragments can be obtained in different ways. In one embodiment, they can be obtained by screening using TCSP on a bank of bacteriophages that express specific antibodies. In another embodiment, they can be obtained in a living organism, using a peptide or protein including sequence SEQ ID N o 1, SEQ ID N o 2, or SEQ ID N o 3 for the detection of antibodies that bind specifically to a peptide including sequence SEQ ID N1 and which are not induced in a host after its infection by T. cruzi , in which the use leads to the immunization of the organism against the TCSP peptide.
[0061] Yet another aspect of the invention is the use of TCSP, and in particular TCSP including sequence SEQ ID N o 1, SEQ ID N o 2 or SEQ ID N o 3, in a vaccine composition, making it possible to immunize a human at least partially against a disease other than Chagas disease, and in particular against autoimmune cardiomyopathy, myocarditis and systemic lupus erythematosus. This vaccination can be performed by injection of a single dose or a plurality of doses. In these compositions, the TCSP can be used as such, as a peptide, or in biotinylated form and/or linked to an avidin derivative, and in particular an avidin derivative obtained by chemical and enzymatic modification, known as NeutraLite Avidin. The composition can include solvents, additives, buffers and pharmaceutically acceptable carriers, as well as, as the case may be, other active principles.
[0062] In accordance with another aspect of the invention, a peptide or a protein including sequence SEQ ID N o 1, SEQ ID N o 2, SEQ ID N o 3, or a TCSP peptide or a variant of the TCSP peptide is used, insofar as the peptide or the protein has a specific activity with respect to the antibodies in accordance with the invention, in order to identify or isolate a pathogenic agent that binds specifically to NCRA or that is recognized specifically by NCRA. This new method makes it possible to identify the pathogenic agents capable of inducing diseases, other than Chagas disease, that induce the formation of NCRA.
[0063] In some of the uses of TCSP in accordance with the invention, it may be advantageous to mark the TCSP, for example by means of a chromophore or a fluorophore, or another chemical entity that can easily be detected (enzyme, radioactive isotope, biotin, hapten, etc.).
[0064] The following examples illustrate certain aspects of the invention, without limiting it.
GROUP STUDY EXAMPLES
Example 1
[0065] These examples correspond to screening tests performed on a number N of a plurality of human populations. Tables 1 and 2 as well as FIG. 1 show results of these screening tests. The ELISA diagnostic technique used for these tests, as well as the successive steps of the tests, are described here.
ELISA Technique
[0066] The TCSP peptide, represented by a synthetic peptide of sequence SEQ ID N o 1, was adsorbed on polystyrene microplates with a concentration of 1 μg/m. The free attachment sites were then saturated by immunologically neutral proteins (in this case albumin). The microplates were then rinsed with a washing buffer, then dried so as to be ready for use. The samples to be tested were incubated in the wells after 1/20 dilution in a dilution buffer; the antibodies not fixed to the antigenic surface were removed by three washing cycles. The specific antibodies of the TCSP fixed to the microplates were detected by an antibody directed against the human IgG and marked by an enzymatic tracer. A chromogenic substrate of the enzyme used served to expose the attachment of the anti-TCSP by measuring the optical density corresponding to the absorption of the chromogen in an appropriate range of wavelengths, and in particular at a wavelength of around 450 nm.
[0067] Reaction of the TCSP peptide with the NCRA present in the serums obtained from patients infected by HIV.
[0068] The serum samples of patients infected by HIV were tested for the presence of NCRA, for two populations: African patients and Western patients (European and American sources).
[0069] Reaction of the TCSP peptide with serums obtained from “healthy” blood donors, i.e. negative for anti-HIV, anti-HVC, anti-HVB antibodies and syphilis.
[0070] To evaluate the prevalence of antibodies against TCSP, on the basis of the hypothesis that these antibodies were not induced by a T. cruzi infection, European serum samples were used. These serums were obtained by healthy blood donors, as indicated above; these donors are therefore in a better state of health than the average population from which they are obtained.
[0071] To be completely certain with regard to the origin of these antibodies against TCSP, all of the samples were tested in a random order using commercially available kits making it possible to detect a T. cruzi infection; no positive sample was found. However, and in a totally unexpected manner, it was found that a significant percentage of these samples nevertheless contained antibodies against TCSP. It is concluded that T. cruzi uses a highly immunogenic motif that may also be used by other pathogens, and/or that may lead to autoimmune antibodies.
[0072] Reaction of the TCSP peptide with the NCRA present in patient serums: by interacting serum samples and solid surfaces on which the TCSP has previously been adsorbed.
[0073] Reaction of the TCSP with the serums of patients infected by the T. cruzi parasite: Given that the TCSP antigen is derived from a protein of the T. cruzi parasite, it is difficult, by conventional techniques, to distinguish the antibodies induced by the T. cruzi infection from those induced by the autoimmunity mechanism (NCRA). In an ELISA test using the TCSP as an antigen, it was found that the two categories of antibodies are confused; the EIA result is not discriminant.
[0074] The results are documented in Tables 1 and 2 as well as in FIG. 1 . FIG. 1 illustrates, for each population of N patients, the distribution of the reactivity (expressed as optical density) of NCRA with the TCSP peptide used for the trial. The distribution of individual points are represented for each of the populations; the rectangles (boxes) show the semi-interquartile ranges. The solid horizontal lines show the arithmetic mean of each of the populations, and the dotted horizontal lines define 95% of the population.
[0000]
TABLE 1
Confidence
Patient
Number
interval 95%
Standard
Standard
category
N
Average
(min/max)
error
deviation
Healthy
576
0.2833
0.2531
0.3134
0.01535
0.36843
donors
African
192
0.8167
0.7708
0.8627
0.02330
0.32281
HIV
Western
192
0.9976
0.9417
1.0535
0.02834
0.39274
HIV
Chagas
96
0.8228
0.7083
0.9372
0.05766
0.56490
patients
[0000]
TABLE 2
Confidence
Patient
Mini-
1rst
Median
interval 95%
3rd
Maxi-
category
N
value
quartile
value
(min/max)
quartile
value
IQR
Healthy
576
0.026
0.0400
0.0795
0.0640
0.0970
0.4076
1.614
0.3676
donors
African
192
0.050
0.6393
0.8575
0.8200
0.9020
0.9988
1.762
0.3595
HIV
Western
192
0.063
0.7808
1.0470
1.0000
1.1000
1.2193
2.150
0.4385
HIV
Chagas
96
0.037
0.2873
0.7055
0.5950
0.9810
1.2640
2.111
0.9768
patients
IQR (Interquartile range) means the semi-interquartile range
Example 2
[0075] In another group of N=79 patients infected with HIV, a clear relationship between the increase in NCRA measurements and the chronological development of these patients on a time scale going beyond two years was noted (see FIG. 3 ).
[0076] This study shows that the monitoring of NCRA concentrations can enable the prognosis of the development the HIV infection and its consequences in terms of cardiac complications.
Examples of Individual Cases (Clinical Trials)
[0077] In cross-studies, the NCRA concentration in male patients infected with HIV was measured, and it was possible to study their cardiac condition. Table 3 shows these results. As an example, for patient PAT — 001, the presence of a high NCRA assay (namely: 8.19) is noted in a blood sample taken prior to his cardiac event.
[0078] These examples show the relationship between the measured NCRA assays and subsequent cardiac events (see PAT — 001, PAT — 004, PAT — 005), and the possibility that a sub-clinical cardiac event can induce the appearance of NCRA at a high dose (see PAT — 009).
[0000]
TABLE 3
Serum
HIV-1
CD4 cells
Viral load
NCRA
tested
Patient
Birth
CDC
[number/
[Copies/
Cardiological
Signal/
(sample
number
year
stage
mm3]
mL]
clinical data
noise
date)
PAT_001
1944
A2
1110
50
Myocardial
8.19
Nov. 15, 2004
(Dec. 20, 2005)
infarction
Mar. 5, 2006
PAT_004
1963
B3
512.5
50
Myocardial
2.21
Sep. 3, 2004
(Dec. 3, 2002)
incident Mar. 7, 2005
PAT_005
1957
A3
333.7
40
Myocardial
2.56
Sep. 9, 2008
(Jun. 18, 2003)
infarction
Dec. 14, 2008
PAT_009
1945
A3
488.8
50
Infarction
25.15
Sep. 23, 2004
(May 3, 1994)
without prior
Q wave
Nov. 3, 2000
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Antibodies which specifically bind to a peptide having the sequence Ala-Ala-Ala-Pro-Ala-Lys-Ala-Ala-Ala-Ala-Pro-Ala-Lys-Thr-Ala-Ala-Ala-Pro-Val (SEQ ID N o 1), and which are not induced in a host following an infection of the host with T. cruzi.
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FIELD
[0001] The present invention relates to elevator installations and particularly to the passive generation of electrical energy while such an elevator installation is in operation.
BACKGROUND
[0002] The use of piezoelectric elements has been proposed previously within the field of elevators to generate control signals, which are fed to an elevator controller enabling the controller to regulate operation of the elevator. For example, JP-A-2002068618 and U.S. Pat. No. 6,715,587 B2 both describe the use of piezoelectric elements mounted either between or to one of an elevator car and its associated frame. The piezoelectric elements in these examples are provided as pressure sensors, which generate signals to an elevator controller enabling the controller to determine changes in the load within an elevator car. EP-A1-1700810 and DE-B3-102012108036 likewise describe the use of a piezoresistive element as a pressure sensor to determine the tension in a support means of a conveyor.
[0003] EP-A1-1780159 and EP-A2-0636569 describe elevator operating panels, which are generally provided on each landing to enable prospective passengers waiting on the landing to call an elevator. Similar panels may also be mounted within the elevator car to allow boarded passengers to enter their required destination floor. In both the arrangements, piezoelectric elements are used within the operating panels as buttons such that upon exertion of sufficient pressure by a passenger's finger, the elements generate the required signal to the elevator controller and can also illuminate an LED to indicate acceptance of the passenger's call.
[0004] Accordingly, piezoelectric elements have been used within elevators to generate control signals either for determining the changes in the load within an elevator car or acting as call signals for transmission to the elevator controller.
[0005] However, since load changes within the elevator car occur rather intermittently and buttons on the operating panel have a small cross-sectional area and can be operated with relatively little pressure, neither of these applications of piezoelectric elements within elevators is sufficient to generate a reliable supply of energy.
SUMMARY
[0006] The present invention has been developed to overcome the above-identified problems related to the described prior art.
[0007] An objective of the present invention is to provide an elevator and method to passively and reliably generate electrical energy while an elevator installation is in operation.
[0008] The elevator installation comprises an elevator car, a tension member for supporting and moving the elevator car, a pulley engaging with the tension member wherein piezoelectric elements are applied to or embedded within the tension member, and a power storage unit having an input electrically connected to at least one anode and at least one cathode of the piezoelectric elements. Thereby electrical energy generated by the piezoelectric layer can be harvested in the power storage unit.
[0009] In use, although the tension exerted on the tension member by the loads within the elevator car is primarily absorbed by the tension member itself, some tension will inherently be transmitted to the piezoelectric elements. Accordingly, variations in the number of passengers and thereby the load of the elevator car will tend to stretch and contract the piezoelectric elements resulting in the generation of electrical energy.
[0010] Moreover, and more particularly, the tension member undergoes substantial compression each time it is deflected by any pulley along its travel path. Typically, the rated speed of pulleys within an elevator installation, and thereby that of the tension member they engage, is relatively high. Given this relative high speed and the substantial compressive force differentials exerted on the piezoelectric elements on or within the tension member during engagement with pulleys, a significant and reliable supply of electrical energy can be generated by the piezoelectric elements when the elevator is in operation.
[0011] Preferably, the piezoelectric elements are incorporated within a piezoelectric layer which can be formed on a surface of the tension member or embedded within the tension member. Such piezoelectric layers are readily available and for an existing tension member are easily applied to an outer surface. Alternatively, the piezoelectric elements can be embedded individually or in layer form during the manufacture of a new tension member.
[0012] The tension member can comprise at least one tensile carrier surrounded by a casing. In this example, the majority of the tension exerted on the member is transmitted through the tensile carrier. The casing can be formed of a suitable material to protect the tensile carrier from corrosion and other environmental conditions. The casing material may also be selected to enhance engagement with the pulley or reduce noise during such engagement. Typically, the tensile carrier is formed from steel and the casing is formed from a plastic such as polyurethane.
[0013] Energy generated can be transferred into an electrical energy bank within the power storage unit and can be stored for subsequent use. The electrical energy bank may comprise batteries, capacitors, fuel cells or any other form of DC electrical energy storage.
[0014] Depending on the respective voltage ratings of the piezoelectric elements and the electrical energy bank, it may be necessary to insert a DC to DC converter between the input of the power storage unit and the electrical energy bank.
[0015] Preferably, energy harvested within the power storage unit can be supplied to external electrical loads via one or more outputs. If the external load has the same voltage rating as the energy bank it can be supplied from a DC output connected directly to the energy bank. Alternatively, the voltage from the energy bank can be bucked, boosted or otherwise transformed by a DC to DC converter to supply external electrical loads having different voltage ratings via a further DC output. Furthermore, a DC to AC inverter can be used to invert the DC power from the energy bank into AC power, which can be supplied to external electrical loads via an AC output.
[0016] In a preferred embodiment the power storage unit is mounted to the elevator car. Accordingly, energy harvested can be used to supply electrical loads within the car and this enables at least a reduction in the rating of any travelling cable used to power the electrical loads within the car if not enabling the design engineer to dispose of the travelling cable completely.
[0017] The invention further provides a method for providing electrical energy within an elevator installation comprising the steps of providing a tension member to support and move an elevator car, providing a pulley for engagement with the tension member, applying piezoelectric elements to or embedding piezoelectric elements within the tension member, and electrically connecting the piezoelectric layer to a power storage unit.
[0018] Subsequently, the electrical energy harvested can be supplied from the power storage unit to an electrical load.
DESCRIPTION OF THE DRAWINGS
[0019] By way of example only, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, of which:
[0020] FIG. 1 is an exemplary schematic showing a conventional arrangement of components within an elevator installation according to the present invention;
[0021] FIGS. 2A-2C are cross-sectional views of alternative tension members according to exemplary embodiments suitable for use in the elevator installation of FIG. 1 ,
[0022] FIG. 3 is a perspective view of an end connection for connecting the tension member of FIG. 2B to the car of FIG. 1 ; and
[0023] FIG. 4 is a schematic of an exemplary embodiment of a power storage unit in which energy generated by the piezoelectric layer of FIGS. 2B and 3 is harvested.
DETAILED DESCRIPTION
[0024] FIG. 1 illustrates an exemplary embodiment of a conventional arrangement of components within an elevator installation 1 . An elevator car 2 and a counterweight 4 are supported on a traction member 6 within an elevator hoistway 12 . In this example, the tension member 6 has a 1:1 roping ratio whereby it extends from an end connection 30 fixed to the car 2 up the hoistway 12 for engagement through a wrap angle α with a traction sheave 14 driven by a motor 16 , over a deflection pulley 18 and subsequently back down the hoistway 12 to a further end connection 30 fixed to the counterweight 4 . Naturally, the person skilled in the art will easily recognize that alternative roping arrangements are equally applicable and that the traction sheave 14 and its associated motor 16 can be mounted within the shaft 12 to provide what is conventionally known as a machine-room-less (MRL) installation, as shown, or alternatively can be provided in a separate and dedicated machine room.
[0025] In operation, as the traction sheave 14 is rotated by the motor 16 , it engages with the traction member 6 to vertically move the car 2 and counterweight 4 in opposing directions along guiderails (not shown) within the hoistway 12 .
[0026] FIGS. 2A-2C are cross-sectional views of alternative tension members according to exemplary embodiments of the invention which are suitable for use in the elevator installation 1 of FIG. 1 . In the example depicted in FIG. 2A , the tension member 6 is in the form of a flat belt having a plurality of tensile carriers 9 surrounded by a casing 10 . A piezoelectric layer 21 incorporating a plurality of piezoelectric elements 20 is also embedded within the belt casing 10 .
[0027] FIG. 2B shows an alternative arrangement wherein the casing 10 of the belt 6 no longer forms a flat surface but instead provided a plurality of V-shaped ribs 22 . The engagement of these ribs 22 with corresponding grooves provided on the traction sheave 14 and deflection pulley 18 not only provides guidance of the belt 6 as it is driven by the traction sheave 14 to move the interconnected car 2 and counterweight 4 through the hoistway 12 but can also enhance the traction between the belt 6 and the traction sheave 14 . Contrary to the previous embodiment, the piezoelectric layer 21 is provided on a flat exposed surface of the belt 6 opposite to the ribs 22 .
[0028] FIG. 2C illustrates a further exemplary embodiment, wherein the tension member 6 is in the form of a round rope having one or more tensile carriers 9 surrounded by a casing 10 . In addition to the tensile carriers 9 , a plurality of piezoelectric elements 20 are also embedded within the casing 10 .
[0029] Typically, the tensile carriers 9 will by formed of steel wires and the casing 10 can be formed from a plastics material such as polyurethane.
[0030] In use, although the tension exerted on the tension member 6 by the opposing loads of the elevator car 2 and counterweight 4 , respectively, is primarily absorbed by the carriers 9 within the tension member 6 , some tension will inherently be transmitted to the casing 10 and to the piezoelectric elements 20 . Accordingly, variations in the number of passengers and thereby the load of the elevator car 2 will tend to stretch and contract the piezoelectric elements 20 resulting in the generation of electrical energy.
[0031] Moreover, and more particularly, the tension member 6 undergoes substantial compression each time it comes into traction engagement as it passes over the wrap angle α of the traction sheave 14 and additionally as it is deflected over any deflection pulleys 18 along its travel path.
[0032] The rated speed of a traction sheave 14 , and thereby that of the tension member 6 it drives, will vary widely depending on application. Typical factors that are taken into consideration include sheave diameter, wrap angle α, rated load, travel height, roping ratio and tension member type. Consequently, the traction sheave 14 may have a rated speed ranging from the tens to the hundreds of revolutions per minute (rpm).
[0033] Given, firstly, the relatively high speed of the traction sheave 14 and therefore of the tension member 6 , and secondly, the substantial compressive force differentials exerted on the piezoelectric elements 20 on or within the tension member 6 during engagement with the traction sheave 14 and deflection pulleys 18 , a significant and reliable supply of electrical energy can be generated by the piezoelectric elements 20 when the elevator 1 is in operation.
[0034] FIG. 3 is a perspective view of an end connection 30 for the connecting the tension member 6 of FIG. 2B to the elevator car 2 of FIG. 1 . A free-end of the tension member 6 is looped over a wedge 32 which is subsequently inserted into a corresponding wedge socket 34 and held in place by a removable projection 36 . The clamping forces acting on the tension member 6 by the wedge and socket ensures that, in operation, there is substantially no slippage of the tension member 6 out of the socket 34 . An exposed section of the free-end of the tension member 6 is secured to the parallel incoming section of the tension member 6 by one or more clamps 38 . The socket 34 is connected to the elevator car or frame thereof by one or more bolts 40 .
[0035] With respect to the piezoelectric layer 21 applied to the tension member 6 , anode(s) and cathode(s) of the piezoelectric elements 20 are extracted therefrom and connected to a first insulated wire 24 and to a second insulated wire 26 , respectively. The DC voltages supplied along these wires 24 and 26 are used as an input DC in to the power storage unit PSU which is mounted on the elevator car 2 as shown in FIG. 1 and which will be further described with reference to FIG. 4 .
[0036] Within the power storage unit PSU, the electrical energy from the input DC in can be feed through a DC to DC converter 46 and is ultimately stored in an energy bank 48 , which in this instance comprises a plurality of rechargeable batteries 50 . Naturally other forms of DC electrical energy storage such as capacitors, fuel cells etc. are equally feasible.
[0037] Power harvested in the DC energy bank 48 can be fed directly to a first DC output DC out 1 and supplied further to electrical loads operating with the same voltage rating as the energy bank 48 . Alternatively, the voltage from the energy bank 48 can be bucked, boosted or otherwise transformed by a further DC to DC converter 46 to supply external electrical loads having different voltage ratings via a second DC output DC out 2 . Furthermore, a DC to AC inverter 52 can be used to invert the DC power from the energy bank 48 into AC power, which is supplied to external electrical loads via an AC output AC out . Accordingly the power harvested within the power storage unit PSU can be supplied to electrical loads within the car 2 such as lighting, ventilation, operating panels etc.
[0038] Having illustrated and described the principles of the disclosed technologies, it will be apparent to those skilled in the art that the disclosed embodiments can be modified in arrangement and detail without departing from such principles. In view of the many possible embodiments to which the principles of the disclosed technologies can be applied, it should be recognized that the illustrated embodiments are only examples of the technologies and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims and their equivalents.
[0039] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
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An elevator installation and method to passively and reliably generate electrical energy while an elevator installation is in operation includes an elevator car, a tension member for supporting and moving the elevator car, and a pulley engaging with the tension member. Piezoelectric elements are applied to or embedded within the tension member. As the tension member is driven to move the elevator car up and down along an elevator hoistway, the tension member also engages with the rotating pulley. Force imparted to the tension member during this engagement with the pulley is transmitted to the piezoelectric elements which consequently generate electrical energy.
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This is a continuation-in-part of application Ser. No. 361,137, filed Jun. 5, 1989 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to floor panels composing the free access floors of OA (Office Automation) rooms, general business offices, etc. which accommodate various types of equipment, such as office automation devices, computers, etc.
2. Prior Art
Free access floor panels used conventionally include those made of aluminum or aluminum alloys, steel, inorganic materials of concrete system, etc., synthetic resins, and wood.
The free access floor panels are shaped into guadrates, and laid directly on the floor or installed such that they are supported on a specified level by props. The floor thus formed is called a "free access floor", and in many cases, the very heavy equipment, such as computers with peripheral devices, and other OA devices, are installed thereon.
The floor panels for the free access floor made of metals, such as steel, and aluminum alloys include bottom plates having a reinforced construction with uneven surfaces integrated with nearly square top plates. Carpeting made of woven fabrics and unwoven fabrics, or sheets of synthetic resin tiles, etc. are bonded on the upper surfaces of the top plates as finishing materials.
The characteristic features of conventional free access floor panels in terms of the material quality are described as follows:
Conventional floor panels made of aluminum are of merit because they have a high degree of finishing precision, but they also have the following drawbacks. For instance, since the aluminum used for this type of floor panel has a Young's modulus which is about one third that of steel, it is necessary for the aluminum panel to be used in a weight adequate enough to have a Young's modulus similar to that of a steel panel so as to obtain the required strength. This, however, naturally invites increases in cost. Furthermore, since such panels require die casting machine work for its manufacture, productivity is lower in comparison with steel floor panels.
Panels using inorganic materials such as a concrete system, etc. are superior in fire resistance and also low in cost. However, they are generally weak to impact and therefore, are not suitable to be used in a form of a large panel. Besides, since they are heavy, it is difficult to execute construction and layout when using them. Also, it is not desirable to use them in buildings. In addition, they have the disadvantage of creating the dust and easily chipping. Consequently, they are usually covered with steel pans and carpeting materials (for example, U.S. Pat. No. 3,811,237).
Panels made of synthetic resin and wood are advantageous in that they are low in cost and light in weight. However, they are inferior in fire resistance since they easily burn. Also, since they are low in strength, they are laid directly on the floor or used as small panels and thus their use is limited. Therefore, countermeasures must be taken such as covering them with steel sheets so as to improve fire resistance and strength U.S. Pat. No. 4,035,967 and U.S. Pat. No. 4,085,557).
The conventional panels made of steel have advantages in that they are as light weight as aluminum and about one half the weight of concrete system material. They are also high in strength, and have less deflection because the Young's modulus of steel is about three times that of aluminum. However, when the panels are manufactured by be welding as is conventionally done to secure high strength even though they are hollow (for example, U.S. Pat. No. 3,380,217 and U.S. Pat. No. 3,696,578), the welded portions are burnt and oxidized even if the surface treated steel sheets are used for rust prevention, resulting in the formation of rust. Consequently, these panels have the disadvantage in that they need the rust prevention treatments, such as coating after the assembly.
The structural features of conventional free access floor panels will be described below.
Because the floor is formed by laying out identical plates for the entire floor, when there is a difference in the direction and height at the four corners of the free access floor panels, weakness and instability is caused. Therefore, it is necessary to manufacture flat panels with a great degree of accuracy. Also, during installation if the degree of flatness of the underfloor ground is not satisfactory, it will result in floor surface being unsteady. As a result, installation requires a lot of time and labor in order to adjust the unsteadiness. A countermeasure taken against shakiness is to make the panel material into a triangular shape so that shakiness is prevented by forming an aggregate of three-point supporting components. With this countermeasure, even though the panels are virtually square in shape, they are bendable along their diagonal lines, thus solving the foregoing problem (e.g. U.S. Pat. No. 3,852,928).
The inside of a room in which the free access floor is installed needs, for the purpose of maintenance of the equipment therein, a specified temperature be maintained and minimization of noise caused by walking as well as sounds coming from the equipment. The disadvantages of conventional free access floor panels in view of these requirements are as follows.
To achieve sound insulation and thermal insulation to a certain extent, synthetic resin tiles and carpeting materials are bonded to the upper surfaces of the top plates, but such measure are neither sufficient nor positive as a means to solve these problems sufficiently. It has also been attempted to fill the inside of the floor panel with foam concrete as part of the countermeasures, but it is not easy to inject the concrete into the panels. Thus, there has been a problem with its workability. Furthermore, as another attempt, CFRC (carbon fiber-reinforced cement) and GRC (cement reinforced with glass fiber) have been packed inside of the floor panels, but this also has its drawbacks including a high degree of shrinkage/distortion, heavy weight and high cost.
SUMMARY OF THE INVENTION
The free access floor panels of the present invention were obtained after conducting various studies to solve the above described problems, while keeping the advantageous points of the prior art.
It is a first object of the present invention to eliminate the necessity of providing rust preventing treatment to the welded portions of the panels as was required conventionally, even when surface-treated steel sheets are used for the top plates, by assembling without welding.
As a result, the free access floor panels of the present invention have the following characteristics. Firstly, the free access floor panel of the present invention comprises a top plate and a bottom plate which are surface treated steel plates formed into specified shapes by press-forming. The top plate and the bottom plate are integrated into a single unit by crimping (pressure-fastening) their edge areas along almost their entire circumference. Also, with vertical walls formed in either the top plate or the bottom plate, the peripheral (circumferential) surface is formed, and props provided inside of the vertical walls are crimped to either the top plate or the bottom plate at the portions contacting thereto.
When the metal top plates and bottom plates made of surface treated steel panels (sheets) are used for the floor panels with the foregoing structure, since integration of the top and bottom plates is effected by crimping (pressure-fastening), the whole panels do not have portions burnt by welding nor are the exposed portions subjected to corrosion, such as exposed metal portions. Accordingly, surface treated steel sheets can sufficiently maintain corrosion resistance. In addition, the props provided inside of the upright walls, and the truss structure as well as the hollow structure formed by those props, bring about light weight and high strength for the panels, providing a load-withstanding structure.
The next object of this invention is to provide free access floor panels having a structure that prevents unstableness. Such panels are obtained by applying the technique of combining triangular panels as described in the previously quoted U.S. Pat. No. 3,852,928 to the structural design of the steel panels used of this invention. More specifially, either the top plates or the bottom plates are divided along their diagonal lines keeping the advantage of using square form top plates and square form bottom plates to construct quadritic panels which are easy to handle by integrating these plates together.
When such panels are used, even if the ground under the floor is not satisfactorily flat, the panels can be deformed at their divided portions along the diagonal lines, conforming themselves to the contour of the underfloor ground surface. As a result, unstableness is no longer a problem.
Still another object of the present invention is to provide free access floor panels which are light in weight and high in heat insulating performance as well as sound insulation. The panels also improve workability when filling the space between the top plate and the bottom plate with heat insulating material, sound insulating material, etc., while maintaining the advantages of metal floor panels, such as high rigidity and flexibility with respect to processing.
The characteristic feature of the floor panel is that hollow grains of inorganic material or a solidified core (formed products) are packed in the space between top and the bottom plates. In such a floor panel, the hollow grains of inorganic material or the core act to insulate heat and sound, also to protect from fire. In addition, they serve to reinforce the entire floor panel. Therefore, it is possible to make the top and bottom plates thinner, and as a result, even if hollow grains of inorganic material are packed inside, the entire body can be reduced in weight relatively.
In manufacturing, since the inorganic hollow grains have fluidity, they can be packed evenly and easily between the top and bottom plates, without causing distortion. Suitable inorganic hollow grains are those which are hollow inside or those having a large number of closed cells inside. In particular, hollow "shirasu (white sand) balloon" obtained by baking volcanic ash in Kyushu of Japan is preferable. Also, formed products obtained by processing porous inorganic grains, such as pearlite and sepiolite may be used. The artificial ceramic inorganic hollow grains, such as those made into ceramic porous material by mixing swelling resins in ceramics as starting materials which use diatomaceous earth, bentonite, etc., then by treating the mixture with dry-sintering after bringing it into a gelatinous state by adding the swelling agent (Japanese Patent Application Kokai No. 1985-46978); the grains having a porous core at the center portion with dense shells formed along the peripheries (Japanese Patent Application Kokai No. 1986-20646) etc. may be used.
The inorganic hollow grains are packed inside the floor panels as they are, or in a fluid state after being mixed with various types of inorganic or organic binders or they can be formed into a solid body in advance and then placed between the top and bottom plates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 3 illustrate free access floor panels, according to the objects of this invention, which are improved to be free of rust even when they are made of steel, in which:
FIG. 1 is a bottom view showing an example of free access floor panels:
FIG. 2 is an enlarged sectional view taken along the line 1--1 in FIG. 1.
FIG. 3 is an end sectional view of the essential portion of another example of free access floor panels;
FIGS. 4 through 9 are diagrams illustrating free access floor panels developed to prevent the possible occurrence of instability and weakness as is case in using triangular floor panels, even though the panels are formed into quadrates, in accordance with another object of the present invention, in which:
FIG. 4 is an enlarged sectional view taken along the line 5--5 in FIG. 4;
FIG. 5 is a plan view of an embodiment showing the surface material is partially broken off;
FIGS. 6 and 7 are enlarged sectional views showing the divided portions, respectively;
FIG. 8 is a perspective view showing an example of bottom plates;
FIG. 9 is a sectional view showing the another embodiment of the free access floor panel, corresponding to FIG. 4;
FIGS. 10 through 14 are diagrams illustrating still another embodiment of the present invention, providing the free access floor panels with excellent heat insulating performance and superior sound insulating performance, in accordance with still another object of this invention, in which:
FIG. 10 is a partially broken bottom view of a free access floor panel;
FIG. 11 is an enlarged sectional view taken along the line 10--10 in FIG. 10;
FIGS. 12 and 13 show another embodiment of this invention, wherein FIG. 12 is a bottom view and FIG. 13 is an enlarged sectional view along the line 12--12 in FIG. 12;
FIG. 14 is a sectional view of an end portion of another embodiment; and
FIG. 15 is an enlarged sectional view of another embodiment of the present invention taken along the line 1--1 in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Hereunder, a detailed description on the embodiments of this invention will be provided with reference to the accompanying drawings.
The description of the free access floor panels which are improved to be hardly rusted even though they are made of steel, in accordance with the first object of the invention, will be provided with reference to FIGS. 1 through 3.
As should be apparent from these Figures, the free access floor panel includes a top plate 1 and a bottom plate 2. These plates are steel sheets and their surfaces are galvanized, etc. The bottom plate 2 is provided, along its four sides, with upright walls 3 formed by press-forming. The upper portions of these upright walls 3 are formed into horizontally folded-back (bent) joint flanges 5, and grounding underbodies 6 (the bottom portions coming into contact with the ground) of the bottom plate 2, which are to become the bottom of the floor panel, are provided with props (ribs) 4 formed in a manner to protrude toward the upper side surface. In the top plate 1, engaging holes 7 are disposed at positions corresponding to a plural number of props 4 of the bottom plate 2, and their edges which stick out downward and are then bent to fold are fastened to the upper portions of the props 4 of the truss structure by crimping them. The edges of the top plate 1 along its four sides are bent downward and engage, by crimping, with the joint flanges 5 of the bottom plate 2. At locations on the inner side of the above mentioned edges, pressed grooves 8 are formed, and the backsides of the grooves are in contact with the upper edges of the bottom plate 2.
FIG. 3 shows an example of another crimping structure, and is a longitudinal sectional view of the essential portion. In this example, the peripheral portion of the bottom plate 2 is bent further downward, and the top plate 1 is crimped to the upper portions of the props 4, while also crimping the joint flange 5 of the bottom plate 2, so as to enfold it.
In each example of the free access floor panels of the present invention, the bottom plate 2 is provided with upright walls 3 and props 4, but the invention is not limited to them, and accordingly the steel floor panels may be diversified such that the top plate is provided upright walls and props. Other structures may also be designed within the principles of the present invention.
The free access floor panels having the structures mentioned above make it possible to maintain the amenity in office environment without causing trouble, while those panels are made of steel. These floor panels sufficiently withstand various loads of OA devices, computers and other equipment, and they are light in weight so that changes in the layout of the office can be made optionally. In addition, changes in wiring, etc. in these floor panels can be made easily. Thus, the invention provides a useful free access floor panels for intelligent devices and equipment.
Also in the manufacture, since the panels are made by press working without requiring machining operation, in comparison with those made of aluminum, etc., they can be obtained with higher productivity and at lower cost.
Next, a description will be given on the free access floor panels which are improved to be free of unstableness in accordance with another object of this invention with reference to FIG. 4 through FIG. 9.
FIG. 4 shows an embodiment of this invention, in the form of an enlarged sectional view taken along the line B--B in FIG. 5, and FIG. 5 is a plan view of an embodiment of the floor panel with its surface covering material partially broken.
In this example, onto the surface of the free access floor panel made of steel and comprised of square form top plate and bottom plate 2, a carpet as the facing material 4 is bonded. The top plate 1 is characteristic in that it is divided into two pieces of nearly triangular plates, along the diagonal line or in the vicinity of it. Then, for each of the two pieces thus obtained, diagonal ribs (ribs provided along diagonal lines) 13 are formed. The division described above may be made in a cross-form in order to obtain four pieces, or part of the corner portions of the top plate may be cut off.
The diagonal ribs 13 may be formed by bending the edges of the divided portions 15 of the top plate 1, or, as shown in FIG. 6, they may be formed by cutting and raising section of the bottom plate 2 then by fixing the raised portions to the undersides of the top plate 1 in a form to be in contact with them. Also, as shown in FIG. 7, as a diagonal rib, a separate member may be fixed.
FIG. 8 is a perspective view showing an example of the bottom plate 2 of the free access floor panel as shown in FIG. 4. At the corners of the quadrate, which are located on the dividing line of the top plate 1, slits 16 reaching down to the bottom are formed. The portion 17 corresponding to the divided portion 15 of the top plate 1 forms a flat surface. The portions except for the portion 17 corresponding to the divided portion may take any form. In the Figure, they have a form capable of securing proper depressing strength of the top plate 1 and bending and breaking strength of the whole body of the panel, during the use after completion of the panel by assembling the bottom plate 2 with the top plate 1.
In the examples described above, the top plates 1 are divided, but FIG. 9 shows an example which is the opposite to the above. In the example of FIG. 9, the bottom plate 2 is divided into two. At the divided portion 18 of the bottom plate 2, the diagonal ribs 13 are further bent outward, then fixed to the bottom surface of the top plate 1, and the spaces between the top plate and the bottom plate 2 are filled with padding material. Those used as a pad include light weight foam concrete, foam resin, wood, and honeycomb core. Also in such examples, when the degree of flatness of the ground under the floor is low, the panels can conform to the shape of the ground by deforming themselves at the divided portions 18 along the diagonal lines, thereby not causing the floor to shake or become unstable.
The free access floor panels mentioned above are provided with legs 19 at their four corners. When greater strength is required, auxiliary legs 20 which are a little shorter than the legs 19, are provided at appropriate intervals along the divided portions 15 and 18. The width of the divided portions 15 and 18 is preferably 0.5 mm to several millimeters. When this range is set for the foregoing width, the right angled corners of the finished product of the free access floor can fit to a floor surface which has a level discrepancy of up to about 2 mm in the state of completion of construction work.
In this invention, it goes without saying that a "quadrate" means a square in the orthodox sense, but a rectangle which is different in longitudinal and transverse length, or having a form with corners cut off, are also included in the meaning of "quadrate".
The free access floor panels having the structures described in detail above do not cause shakiness, through absorbing the unflatness in the floor surface, as is the case when using triangular panels, in spite of the fact they are quadrate panels. It is also easier to carry floor panels of the above-described form than it is to carry triangular panels. Also, they can make the setting-out and shakiness adjustment unnecessary. Therefore, installation becomes very simple, and construction costs can be reduced.
In addition to the embodiment referred to in FIG. 9, hereunder a description will be provided of free access floor panels which are improved to have excellent heat insulating performance as well as outstanding sound insulating performance, achieving still another object of this invention through the embodiments with reference to FIGS. 10 through 14.
FIG. 10 is a partially broken bottom view of a free access floor panel, and FIG. 11 is an enlarged sectional view taken along the line C--C in FIG. 10.
In this example, both the top plate 1 and the bottom plate 2 are made of steel sheets. When the outer walls 28 on its four side edges and the ribs inside are formed by press-forming, the metal bottom plate 2 becomes integrated with the quadrate and flat top plate 1 by, for example, peripheral crimping. Thereafter, the inorganic hollow grains 23 are injected through an injection hole into the inside space formed by the top plate 1 and the bottom plate 2. Onto the upper surface of the top plate 1, tiles 40 are bonded. The inorganic hollow grains 23 filling the hollow space 27 between the top plate 1 and the steel bottom plate 2 are, in this example, the shirasu balloon of 0.6 to 0.21 mm in grain size (from Aso Cement Co., Ltd. in Japan; brand name Skarlite No. 2). As an example, the grains obtained by mixing this product with cement by arranging such that the volume ratio of shirasu to cement becomes about 3-5 to 1, then by kneading the mixture throughly in a mixer by adding about 50 weight % of water, are poured in and formed. Since they have a very high flowability, they can be applied to the cast-forming method mentioned above.
The cement-mortar filler of the inorganic hollow grains that is formed between the metal top plate 1 and bottom plate 2 is 0.6 to 0.9 in specific gravity in absolute dry condition, and 0.10 to 0.40 Kcal/m.hr.°C. in thermal conductivity as the formed product. This filler product has about two times the strength in both bending and compression, in comparison with foam concrete with the same specific gravity. Also, when glass fiber of about 1 to 20 weight % is added, the strength can be further increased.
FIGS. 12 and 13 show the other embodiment. FIG. 12 is a bottom view, and FIG. 13 is an enlarged sectional view taken along the line D--D in FIG. 12. In this example, a filler injecting hole 21 is formed at the center of the steel bottom plate 2. The floor panel is mounted on a turntable so that rotation is made with the foregoing injecting hole 21 as the center, and by using centrifugal force, filling can be performed quickly and completely up to the very corners of the filling space formed by the top plate 1 and the bottom plate 2.
The small holes provided at four corners are the dehydration (moisture drying) holes 22. The filler injecting hole 21 at the center is provided with a stepped portion around it for increasing the strength of the bottom plate 2 and also for facilitating fitting a cap 25 after the filling.
The filling of the inorganic hollow grains, etc. into the space inside of the free access floor panel can be effected also to those having other shapes, in addition to the quadrate panels. Besides, other arrangements can be made to the panels of the present invention. The divided portion 15 is formed in the metal top plate 1 by forming the ribs provided along the diagonal line, thereby making it possible for the floor panel to conform to the unevenness of the floor surface. Also, tiles 40 and carpet may be bonded onto the surface of the metal top plate 1 as was practiced conventionally.
As an application of the inorganic hollow grains for the free access floor panels according to this invention, the example of mixing them in cement has been described above. The case to inject the hollow grains before they are solidified, or the case to compact them in either the top plate or the bottom plate and solidify them, then to integrate both the plates have also been mentioned above. However, it is also possible to compact them between the metal top plate 1 and bottom plate 2, after forming and solidifying the grains into specified form.
One example is shown in FIG. 14 (a longitudinal section of an end portion of a floor panel). In this example, the side wall of the metal top plate 1 is provided with an external protrusion 41, and this external protrusion 41 engages with an internal protrusion 42 provided on a cup-form outer wall of the bottom plate 2 so that the integration of these top and bottom plates is effected. In the hollow inside space 27 formed by the foregoing metal top plate 1 and metal bottom plate 2, a core 24 is installed during the assembly of the panel. The core 24 is prepared by forming and solidifying the Shirasu balloon inorganic hollow grains 23, the same as that used in the previously mentioned embodiment, together with carbon fibers, using cement.
Shown in FIG. 15, is another embodiment of the present invention in sectional view along the line 1--1 of FIG. 1. In this embodiment, many elements are the same as that of FIG. 1 except for the construction of the peripheral upright wall. Accordingly, similar elements are given similar referenced numerals. In this embodiment, both the outer peripheral of each of the top plate 1 and bottom plate 2 is bent at substantially a right angle form the upright wall 3 and are joined together by joint flanges 5 which are crimped about the entire periphery.
Thus far, as the medium for forming the inorganic hollow grains 23 into a compact body (core), cement has been referred to as the example. In addition to cement, synthetic resins, such as phenolic resin, or plaster, water glass, etc. may be used.
What have been described above are examples of the embodiments of this invention. The present invention, however, is not limited to those embodiments, and within the latitude in accordance with the specifications necessary for achieving the objects of this invention, the top plate 1, the bottom plate 2, and the inorganic hollow grains 23 may be modified to have structures which have been described above with freedom of choice.
The free access floor panels according to this invention, on which the detailed description has been made, have structures capable of sufficiently meeting the three objects mentioned in the Summary of the Invention. That is, while these panels are made of steel, they hardly become rusty, and also, even when the constructed floor is not finished into a flat plane, the panels absorb discrepancies in flatness thereby providing the floor with stability. Furthermore, during the manufacture, it is easy to fill the inorganic hollow grains between the plates with a high degree of workability, and the cement core installed inside has less shrinkage distortion. The panels are light in weight, remarkably high in heat insulating performance as well as in sound insulating performance, and can withstand a great degree of overloading. In addition, they have a fire resistant structure. Therefore, they are excellent floor materials capable of meeting every requirement for forming free access floors, particularly those used for the rooms accommodating office automation devices, computers, etc.
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A free access floor panel including a flat top plate and a bottom plate which are crimped at the upper peripheral edges into a single unit, the bottom plate having an upright wall along the peripheral edges and projected props inside thereof. The top and bottom plates may be made from surface-treated metal sheets so as to prevent damage thereto, and the floor panel thus formed can be filled with porous inorganic materials to upgrade sound proofing.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed on Provisional Patent Application Ser. No. 61/335,822 filed Jan. 12, 2010.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO A “SEQUENCE LISTING”, A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON COMPACT DISC
[0003] Not Applicable
BACKGROUND OF THE INVENTION
Field of the Invention
[0004] When, as is often the case, products such as snacks are provided in flexible sealed containers, which must be opened to provide access to the products, and only a portion of the products are to be used, it is necessary to close and re-seal the container in order to preserve the products for future use. The same closing-and-seal problem occurs when one uses a flexible container to store or transport a product. Such closing and resealing presents a problem of convenience and permanency, particularly when the presumably closed and sealed container is subject to handling, as when it is carried from place to place—home to workplace for example. The container itself, once opened and being flexible, is hard to seal. Moreover, manipulating a flexible container to obtain only a portion of its contents is by no means easy.
BRIEF SUMMARY OF THE INVENTION
[0005] In accordance with the present invention these problems are solved through the use of a ring-and-cover unit to which the open top of the container is reliably and sealingly secured with its top held open between a pair of rings for ready access to the container's contents, and with the cover portion of the unit being movable between a closed position sealing the top and an open position exposing the interior of the container. The rings and the cover are movably connected to one another to constitute an easily handled and stored unit.
BRIEF DESCRIPTION OF THE OF DRAWINGS
[0006] FIG. 1 is a three-quarter front perspective view of a flexible container, with its contents, secured to the closed and sealed unit of the present invention;
[0007] FIG. 2 is a cross-sectional view taken along the line 2 - 2 of FIG. 1 ;
[0008] FIG. 3 is a fragmentary rear perspective view of the container unit of FIG. 1 ;
[0009] FIG. 4 is a fragmentary perspective view of the container-unit combination with the unit in open position and contents being inserted into the container; and
[0010] FIG. 5 is a three-quarter perspective exploded view of a flexible container and the closure unit of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] The container closure of the present invention comprises a pair of telescoping rings 2 and 4 between which the upper open end 6 of a flexible container 8 is adapted to be received, and a cover 10 movable between a closed position in which is received within the ring 4 covering the ring opening and an open position exposing the interior of said container 8 . Preferably hinges 12 and 14 flexibly connect the rings 2 and 4 and the cover 10 . The parts may be made of any suitable material.
[0012] The ring 2 comprises a body 16 having a thickened upper portion 18 with an inwardly facing protuberance 20 extending therearound. The ring 4 is designed to releasably fit within and sealingly engage the ring 2 . To that end it comprises a body 22 which telescopes within the body 16 of the ring 3 and which preferably has an outwardly facing recess 24 designed to receive the protuberance 20 of the ring 2 .
[0013] The cover 10 comprises a top wall 26 which covers the exposed interior of the rings 2 and 4 , from which a wall 28 depends, the wall 28 fitting closely within the ring 4 and having an outwardly facing depression 30 designed to receive an inwardly facing protrusion 32 on the ring 4 .
[0014] The ring 4 and the cover 10 are flexibly connected to the ring 2 by flexible strips 12 and 14 respectively defining flexible hinges, thereby to produce a unit the movable parts of which are held together whether the unit is open or closed (Compare FIG. 1 and FIG. 5 ).
[0015] All of the parts may readily be formed by a suitable somewhat resiliently flexible material to permit telescoping and sealing.
[0016] In use, the open top of the flexible container 8 , either empty or with contents, is threaded up through the ring 2 and preferably folded over as at 4 a . The ring 4 is then telescoped within the ring 2 , closely engaging the container top 4 a therebetween so that it remains in place with its top spread open to receive or dispense container contents as the case may be and with the container sealed to the rings. At this point in time the cover 10 is in its open position shown in FIGS. 4 and 5 . When removing or adding contents is finished the cover 10 is moved to cause its wall 20 to telescope within and sealing engage the ring 4 , thus securely closing and sealing the container 8 , producing a unitary assemblage which may readily be stored, handled or transported while preventing the contents of the container from escaping and keeping them protected from adverse exterior elements. When access to the interior of the flexible container is desired, one need merely lift the cover 10 (see FIG. 4 ). The cover remains attached to the rings 2 and 4 , ready to be moved to closing position when that is appropriate.
[0017] To remove the container 8 from the rings 2 and 3 all that need be done is to lift the ring 4 from the ring 2 , the cover 10 preferably remaining in the ring 4 whether it remains in the ring 2 or not.
[0018] While but a single embodiment of the present invention have been specifically disclosed, it will be apparent that many variations of structure may be made without departing from the spirit of the invention as defined in the following claims:
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A device for holding an open-topped flexible container and releasably and reliably closing its open top but readily exposing that open top when access to the interior of the container is desired.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improvement to Exhaust Gas Recirculation (EGR) Systems and in particular to a metal screen affixed to a carbon gasket for sealing the EGR valve to the manifold of an automobile engine and providing an effective barrier to keep large exhaust carbon flakes from entering the EGR system and clogging the valve.
2. Description of the Prior Art
There are several prior art attempts to combine a gasket with a screen to filter fluid streams. For example, Powers U.S. Pat. No. 3,124,930 discloses a catalyst screen attached to a gasket which is placed between the exhaust manifold and engine block. The gases leaving the cylinders will, while very hot, be in contact with the catalyst member. The high temperatures available at this point remove a substantial percentage of the unburned hydrocarbons. Powers does not consider the screen as a blocking member since all of the exhaust must pass through, however, accumulation of carbon particles will eventually totally block the screen and render it useless. The strainer gasket for sanitary piping systems disclosed in Hirsch U.S. Pat. No. 3,421,631 discloses an in-line filter screen which is formed within the gasket. The filter screen shown by Hirsch also suffers from the same defect as Powers and would eventually be clogged with impurities. Crook U.S. Pat. No. 3,206,216 discusses the difficulties associated with combining a screen with a gasket in the prior art and solves the problems with a one-piece gasket/filter. Large flakes would also block the fluid stream and would have to be disassembled periodically.
One prior art attempt by a major automobile manufacturer to solve the problem of valve clogging was to change the structure of the valve. In a notice to service facilities, it was noted that for the 5.0L engine EGR system, two major improvements were made over previous systems. The first was a stainless steel EGR valve. This valve is constructed of stainless steel to reduce the possibility of clogging. The second improvement is the replacement of the EGR solenoids with an electronic vacuum regulator. Although the changes did reduce some of the carbon buildup on the valve itself, it did not solve the problem of carbon building up within the manifold, breaking off in large flakes, and clogging the valve. None of the prior art devices have solved the problem of eliminating large carbon flakes from the fluid stream and preventing blocking of the screening material.
SUMMARY OF THE INVENTION
The Exhaust Gas Recirculation System (EGR) is designed to reintroduce exhaust gas into the combustion cycle which lowers combustion temperature and reduces the formation of Nitrous Oxides (NOx). Nitrous Oxides are a compound formed during the engine's combustion process when oxygen in the air combines with nitrogen in the air to form the nitrogen oxides which are agents in photochemical smog.
There are four basic types of EGR valves: The Integral Backpressure Valve; The Ported EGR Valve; The Electronic EGR Valve; and The Valve and Transducer Assembly EGR Valve. Typical components connected within the system are: EGR valve; Ported Vacuum Switch (PVS); and/or Thermal Vacuum Switch (TVS); and Carburetor EGR port or vacuum tank vacuum source. The amount of gas reintroduced and the timing of the cycle varies by calibration and is controlled by various factors such as engine speed, altitude, engine vacuum, exhaust system backpressure, coolant temperature and throttle angle depending on the calibration. All EGR valves are vacuum actuated.
The principal utility of the invention is to provide a long sought solution to the problem of large carbon particles (flakes) becoming lodged in the valve and holding it open. More specifically, the invention is a stainless steel screen affixed to a carbon gasket which is used to seal the EGR valve to the manifold.
Therefore there is a need for a simple, rugged, inexpensive fluid stream filter in exhaust gas recirculation systems.
It is therefore an object of the invention to provide an improved, reliable, exhaust gas recirculation system.
It is another object of the invention to provide a fluid stream filter in an EGR system.
Still another object of the invention is to provide an efficient fluid stream filter by combining a metal screen with a gasket.
It is also another object of the invention to provide an exhaust gas filter by combining a stainless steel screen with a carbon gasket to seal the EGR valve to the manifold to block carbon flakes from clogging the valve.
These and other objects of the invention will become apparent to those skilled in the art to which the invention pertains when taken in light of the annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically, in cross section, typical prior art EGR assembly.
FIG. 2 shows schematically, in cross section, a typical EGR assembly with a valve carbon control screen and gasket of the invention.
FIG. 3 is a top view of the valve carbon control screen and gasket of the invention.
FIG. 4 is a side view of the valve carbon control screen and gasket of the invention.
FIG. 5 is a side view of a second embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in more detail to the drawings, FIGS. 1 and 2 show a typical Exhaust Gas Recirculation (EGR) system 10. FIG. 1 shows the current and prior art EGR system including an EGR Valve Position Sensor 11, an EGR valve 12, a carbon control screen and gasket 13, and an exhaust manifold 14.
The Exhaust Gas Recirculation (EGR) system is a process where a small amount of exhaust gas is readmitted to the combustion chamber to reduce peak combustion temperatures and thus reduce NOx emissions. An electronic EGR valve 12 is required in Engine Emission Control (EEC) systems where EGR flow is controlled according to computer demands by means of an EGR valve position sensor 15 attached to the valve 12. The valve is operated by a vacuum signal from the dual EGR solenoid valves or the electronic vacuum regulator which actuates the valve diaphram.
When a car is at idle speed, or slow speed, valve pintle 12 is in a lower position (closed) as shown in FIG. 2. As the car accelerates and reaches a cruising speed, the valve 12 is opened by the exhaust pressure passing thru the manifold 14. As long as the valve 12 remains open, the EGR valve position sensor 11 produces a signal to the computer and the engine continues in normal operation. Under normal conditions, as the car decelerates, the valve closes and the return exhaust gas is cut off by valve 12. The EGR valve position sensor 11 (down position) then signals the computer of the status of the engine speed and all systems return to normal. The entire process is begun when the engine is restarted or accelerated and the valve 12 reopens to signal the computer of the status of the engine.
As shown in FIG. 1, if at any time during the operation of the engine, a particle or flake of carbon 16 is released in the exhaust system and enters the EGR valve 12 and becomes jammed between the valve 12 and its seat 17, the valve position sensor 11 will indicate an erroneous status of the valve 12. Failure of the valve position sensor 11 to indicate the proper status of the EGR system 10 will result in: stalling; rough idle; engine surges; poor performance; or poor fuel economy. As long as the engine continues at high speed, the engine performance will not be adversely effected if the valve 12 is in the open (normal) position. At highway speed the valve 12 should be opened. As the car decelerates and comes to a stop, the sensor 11 continues to provide an erroneous high speed signal to the computer and the engine will either stall if running or will not restart if stopped. If a car starts across an intersection and the driver lets off the gas pedal, the engine will stall if the valve 12 is open, the car will suddenly slow down without the stoplights being lit, and a rear end collision may result.
Normally, the car cannot be restarted until the EGR valve is removed and the valve 12 is either unclogged or the EGR valve is replaced. Since the EGR system 10 is part of the emission system, the costs of towing, replacement, and overnight loaner cars are generally borne by the manufacturer. These costs can exceed $200.00 per incident.
Mounting a filter (screen) 18 on the carbon gasket 19 provides a simple, rugged, barrier which prevents carbon 16 flakes from entering the EGR valve system. As shown in FIGS. 3-5, a cup-shaped filter 18 is inserted in the exhaust gas inlet opening 20 and fastened in an appropriate manner, as for example, pressed into gasket 19 and cemented with a high temperature cement to gasket 19. The filter 18 is preferably made from stainless steel wire screen but may also be made from other high temperature resistant filter material such as ceramic. As noted in the above discussion, stainless steel was the choice of one major car manufacturer to solve the problem of carbon in the EGR system. Although the filter 18 is shown as cup-shaped, in some applications, i.e., where the valve 12 does not protrude into the manifold 14, the filter may be flat as it does not need the clearance provided by the cup-shape. The mesh size of the filter 18 is not critical to the performance of the invention since small particles of carbon, e.g., 1/16" may pass thru the EGR system 10 without affecting its operation.
Although the preferred embodiment of the invention uses a carbon gasket 19, a standard manufacturer's part, it could be made of other high temperature resistant gasket materials. The diameter of the rim of screen 18 is dependent on the diameter of the gas inlet 20. The flat rim of filter 18 should be sufficiently large to ensure a gripping fit between the EGR system 10 and the exhaust manifold 14.
FIG. 5 shows a second embodiment of the invention wherein the filter 18 is secured by a second gasket 19' which is placed over the screen 18 to hold the screen 18 firmly in place between the gaskets 19 and 19'. Since the dimensions of the various size EGR systems available on the market may vary, several different sizes of filters 18 will be required to mate with the different sized gaskets. During the flow of exhaust gases from the manifold 14 to gas inlet 20, for example, the filter element screen 18 will deflect any large carbon flakes 16 which will continue flowing thru the exhaust system rather than entering the EGR system 10, while the gasket 19 when initially installed as shown in FIG. 1, prevents leakage of exhaust outwardly between EGR face 21 and manifold face 22. The carbon control screen and gasket 13 of the invention provides an efficient means for modifying existing and new cars during assembly to prevent valve clogging without reworking the EGR system 10.
Although the EGR system 10 shown in FIGS. 1 and 2 is a Ford part, other U.S. auto manufacturer's systems operate on the same principle and suffer from the same valve blockage by carbon flakes and may be improved with this invention. Japanese and foreign manufacturers may also benefit from this invention.
While the invention has been explained with respect to a preferred embodiment thereof, it is contemplated that various changes may be made in the invention without departing from the spirit and scope thereof.
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The invention relates to an improvement to exhaust gas recirculation (EGR) systems and in particular to a high temperature resistant wire screen affixed to the inlet opening of a carbon gasket for sealing the EGR valve to the manifold of an automobile engine and providing an effective barrier to keep large exhaust carbon flakes from entering the EGR system and clogging the valve.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a novel vinyl-polymerizable monomer having a tertiary hydroxyl group and a vinyl-polymerizable functional group and a production method of the monomer. The present invention is also relates to a novel functional polymer having a tertiary hydroxyl group, which is produced by the polymerization of the monomer alone or the copolymerization of the monomer with various vinyl comonomers.
[0003] Because of having the tertiary hydroxyl group, the novel functional polymer simultaneously has a moderate reactivity and hydrophilicity, and therefore, the water content of its hydrogel can be regulated as desired by controlling the content of the tertiary hydroxyl group. The polymer is useful as a medical material because the hydrophilicity of its surface can be easily controlled. The polymer is also useful as a polyol component of a paint, because the pot-life of the paint can be regulated as desired and the rate of the hardening reaction of a paint can be controlled by controlling the content of the tertiary hydroxyl group, thereby providing a paint film with a smooth surface.
[0004] 2. Description of the Prior Art
[0005] It has been conventionally known that the hydrophilicity of a polymer can be improved by polymerizing a vinyl-polymerizable monomer having a hydroxyl group to introduce hydroxyl groups to polymer side chains. By reacting with the introduced hydroxyl groups, various types of other functional groups can be introduced. For example, a copolymer of a monomer having a primary hydroxyl group such as 2-hydroxyethyl methacrylate and a copolymer of a monomer having a secondary hydroxyl group such as 2-hydroxypropyl methacrylate have been widely used as a paint material and a medical material by utilizing their hydrophilicity and reactivity due to the primary or secondary hydroxyl group.
[0006] A polymer having a primary or secondary hydroxyl group, however, may cause problems due to the high reactivity of the hydroxyl group. For example, a polyurethane paint has been widely used as a two package paint comprising a main component including a coating resin and a hardener including polyisocyanate, which are mixed with each other just before its use. Because of an extremely high reactivity of the isocyanate groups of the hardener, the isocyanate groups rapidly react with the primary or secondary hydroxyl groups of the coating resin after mixing the main component and the hardener, thereby causing a problem of a short pot-life (usable life).
[0007] A highly hydrophilic homopolymer is water-soluble and water-swelling. Therefore, for the use in an aqueous condition, a copolymerization of a hydrophobic monomer is practically necessary. To improve the hydrophilicity, a polymer is required to have a large number of hydrophilic groups. The polymer, however, becomes soluble or swelling as the number of the primary or secondary hydroxyl groups increases to cause problems such as a dissolution of the polymer into a contacting aqueous medium, a poor appearance of a coating film surface, and a lowered mechanical strength of a coating film. Thus, no sufficient performance is obtained in the use under an aqueous condition.
[0008] As a vinyl-polymerizable compound having a tertiary hydroxyl group, pinacol derivatives are known from old. In addition, Japanese Patent Publication No. 7-061980, etc. disclose monoesters of hydroxyadamantane. However, the proposed compounds are expensive and poor in the heat stability and the resistance to hydrolysis because of the presence of an ester linkage derived from a tertiary hydroxyl group, thereby largely limiting their application. Although a high heat resistance and a high refractive index attributable to the adamantane structure are recognized, nothing is reported up to the present on the properties attributable to the tertiary hydroxyl group.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a novel vinyl-polymerizable monomer that imparts a moderate reactivity and hydrophilicity to a polymer, thereby solving the problems mentioned above.
[0010] The inventors have found that a vinyl polymer produced by polymerizing a novel vinyl-polymerizable monomer having a tertiary hydroxyl group has a moderate reactivity and hydrophilicity, and have accomplished the invention based on this finding.
[0011] Thus, the present invention relates to a novel vinyl-polymerizable monomer having a vinyl-polymerizable group and a tertiary hydroxyl group, which is represented by the following Formula 1:
[0012] wherein X is a vinyl-polymerizable group; R 1 and R 2 may be the same or different and are each an alkyl group having 1 to 4 carbon atoms; and R 3 is methyl or hydrogen, m is an integer of 1 to 3; with the proviso that two or three R 3 groups when m is 2 or 3 are the same or different from each other.
[0013] The vinyl-polymerizable group X is preferably represented by the following Formula 2:
[0014] wherein R 4 is methyl or hydrogen. Preferred are vinyl-polymerizable monomers represented by the following Formulas 3, 4 and 5:
[0015] wherein R 4 is the same as defined above.
[0016] The present invention also relates to a production method of the novel vinyl-polymerizable monomer.
[0017] The present invention further relates to a polymer having tertiary hydroxyl groups, which is produced by the polymerization of the vinyl-polymerizable monomer of Formula 1 alone or with a comonomer.
[0018] The present invention still further relates to a medical material having its surface made of the above polymer.
[0019] The present invention still further relates to a coating resin comprising the above polymer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is a chart for showing 1 H-NMR spectra of the vinyl-polymerizable monomer prepared in Example 1;
[0021] [0021]FIG. 2 is a chart for showing 13 C-NMR spectra of the vinyl-polymerizable monomer prepared in Example 1;
[0022] [0022]FIG. 3 is a chart for showing 1 H-NMR spectra of the vinyl-polymerizable monomer prepared in Example 3;
[0023] [0023]FIG. 4 is a chart for showing 13 C-NMR spectra of the vinyl-polymerizable monomer prepared in Example 3;
[0024] [0024]FIG. 5 is a chart for showing 1 H-NMR spectra of the vinyl-polymerizable monomer prepared in Example 5;
[0025] [0025]FIG. 6 is a chart for showing 13 -NMR spectra of the vinyl-polymerizable monomer prepared in Example 5;
[0026] [0026]FIG. 7 is a chart for showing 1 H-NMR spectra of the vinyl-polymerizable monomer prepared in Example 6;
[0027] [0027]FIG. 8 is a chart for showing 13 C-NMR spectra of the vinyl-polymerizable monomer prepared in Example 6;
[0028] [0028]FIG. 9 is a chart for showing 1 H-NMR spectra of the vinyl-polymerizable monomer prepared in Example 7;
[0029] [0029]FIG. 10 is a chart for showing 13 C-NMR spectra of the vinyl-polymerizable monomer prepared in Example 7;
[0030] [0030]FIG. 11 is a chart for showing 1 H-NMR spectra of the vinyl-polymerizable monomer prepared in Example 8; and
[0031] [0031]FIG. 12 is a chart for showing 13 C-NMR spectra of the vinyl-polymerizable monomer prepared in Example 8.
DETAILED DESCRIPTION OF THE INVENTION
[0032] The vinyl-polymerizable monomer of the present invention is structurally characterized by:
[0033] (1) having at least one tertiary hydroxyl group;
[0034] (2) having at least one vinyl-polymerizable group; and
[0035] (3) having no ester linkage derived from a tertiary hydroxyl group.
[0036] The vinyl-polymerizable monomer is synthesized by the reaction of a starting compound A for introducing the vinyl-polymerizable group and a starting compound B for introducing the tertiary hydroxyl group. The bonding residue of the starting compound A constitutes the vinyl-polymerizable group X.
[0037] The starting compound A and the starting compound B may be bonded through an ester linkage, an ether linkage, an acid anhydride linkage, an urethane linkage, etc., with the ester linkage being preferred in view of easiness of reaction.
[0038] As the starting compound A, a vinyl-polymerizable compound is usable. Various types of vinyl-polymerizable compounds such as unsaturated carboxylic acid derivatives, styrene derivatives, vinyl ethers, and allyl compounds are converted into the monomer having a tertiary hydroxyl group as far as having a reactive functional group such as hydroxyl group, ester group and carboxyl group. In view of polymerizability and easy availability, the unsaturated carboxylic acid and its ester are preferably used.
[0039] Examples of the unsaturated carboxylic acid include an aliphatic monocarboxylic acid such as acrylic acid, methacrylic acid, crotonic acid and trifluoromethylacrylic acid; an aliphatic dicarboxylic acid such as maleic acid, fumaric acid, itaconic acid and citraconic acid; and an aromatic unsaturated carboxylic acid such as cinnamic acid. These acid may be used in the form of halide. In view of easy availability and high reactivity, acrylic acid and methacrylic acid are preferred. In the present invention, acrylic acid and methacrylic acid are collectively referred to as “(meth)acrylic acid.”
[0040] Examples of the ester of unsaturated carboxylic acid include an aliphatic monocarboxylate such as acrylic ester, methacrylic ester, crotonic ester and trifluoromethylacrylic ester; an aliphatic dicarboxylate such as maleic ester, fumaric ester, itaconic ester and citraconic ester; and an aromatic unsaturated carboxylate such as cinnamic ester. In view of easy availability and high reactivity, the acrylic ester and the methacrylic ester are preferably used.
[0041] In addition, an unsaturated isocyanate compound such as 2-isocyanatoethyl methacrylate and methacryloylisocyanate may be used as the starting compound A.
[0042] As the starting compound B, i.e., the other starting compound for producing the monomer, usable are a polyhydric alcohol having a primary or secondary hydroxyl group in addition to a tertiary hydroxyl group and isobutylene oxide.
[0043] Examples of the polyhydric alcohol include 2-methyl-1,2-propanediol, 2-methyl-1,2-butanediol, 2-methyl-2,3-butanediol, 3-methyl-1,3-butanediol, 2,3-dimethyl-1,2-butanediol, 2,3-dimethyl-1,3-butanediol, 2-methyl-1,2-pentanediol, 3-methyl-1,3-pentanediol, 4-methyl-1,4-pentanediol, 2-methyl-2,3-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,2-butanediol, and 1,4-dihydroxy-1-methylcyclohexane. Optical isomers, if any, may be used singly or in the form of a racemic mixture. In view of easy availability, 2-methyl-1,2-propanediol (isobutylene glycol), 2-methyl-2,4-pentanediol (hexylene glycol), and 3-methyl-1,3-butanediol are particularly preferred.
[0044] In case of using isobutylene oxide as the starting compound B, the compound of Formula 1 can be obtained by directly reacting isobutylene oxide with the starting compound A by a ring-opening addition reaction. Alternatively, an alkylene oxide such as ethylene oxide and propylene oxide is first reacted with the starting compound A by a ring-opening addition reaction, followed by the addition of isobutylene oxide at the termination stage of the ring-opening addition reaction.
[0045] The reaction to bond the starting compound A to the starting compound B is carried out in the presence of a catalyst that can be selected from various types of compounds. In case of using (meth)acrylic acid or (meth)acrylic ester as the starting compound A to carry out the reaction by esterification or ester interchange, examples of the catalysts include, but not limited to, a metal such as alkali metals, alkaline earth metals, aluminum, tin, zinc, lead, titanium, bismuth, zirconium, germanium, cobalt, chromium, iron, and copper; a compound of the preceding metal such as organometallic compounds, salts of organic acids, salts of inorganic acids, halides and hydroxides; an organic sulfonic acid; and a solid acid such as sodium methoxide, lithium methoxide, sodium aluminate, cationic ion-exchange resins, zeolites, silica-alumina, silica-titania, bentonite, montmorillonite, and activated clay. In case of using (meth)acryloyl halide as the starting compound A to carry out the reaction by esterification, usable as the catalyst are a tertiary amine and an inorganic base such as triethylamine, tripropylamine, N,N-diisopropylethylamine, tributylamine, trioctylamine, pyridine, 4-dimethylaminopyridine, 4-pyrrolidinopyridine, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogencarbonate, potassium carbonate, and potassium hydrogencarbonate.
[0046] The temperature for each reaction in the presence of the above catalyst should be suitably selected. In case of using (meth)acrylic acid or (meth)acrylic ester as the starting compound A to carry out the reaction by esterification or ester interchange, the reaction is carried out at 40 to 250° C., preferably 50 to 150° C. while removing alcohol and water being generated. The reaction pressure may be atmospheric, or above or below atmospheric pressure. The reaction is preferably carried out at atmospheric pressure or lower as the reaction-proceeds, more preferably at 300 mmHg or lower. To facilitate the removal of alcohol and water being generated, an azeotropic solvent may be present in the reaction system. In case of using (meth)acryloyl halide as the starting compound A to carry out the reaction by esterification, the reaction is carried out at −20 to 90° C., preferably 0 to 60° C. The reaction fails to proceed sufficiently at lower than −20° C. A temperature exceeding 90° C. is unfavorable because side reactions such as polymerization are likely to occur.
[0047] The method of the present invention for producing the vinyl-polymerizable monomer having a tertiary hydroxyl group may include a step for ring-opening a cyclic ester or a cyclic dimer of oxyacid. The ring-opening reaction is carried out at 40 to 250° C., preferably 80 to 150° C. optionally in the presence of the catalyst mentioned above.
[0048] The vinyl-polymerizable monomer having a tertiary hydroxyl group is easily polymerized alone or copolymerized with various vinyl comonomers by a known polymerization method such as radical polymerization, anionic polymerization and anionic coordination polymerization.
[0049] The copolymerizable vinyl comonomer may be selected from unsaturated carboxylic acids, their esters, styrene, styrene derivatives, conjugated vinyl compounds and α-olefins. The type and the amount of the comonomer are suitably selected depending on the intended use of resultant polymer. The comonomers may be used alone or in combination of two or more. Examples of the comonomer include (meth)acrylates such as methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, stearyl(meth)acrylate, cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, 2-methoxyethyl(meth)acrylate, 2-ethoxylethyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, and 2-hydroxypropyl(meth)acrylate; (meth)acrylates having a phospholipid-like functional group such as 2-(meth)acryloyloxyethyl phosphorylcholine; aromatic vinyl compounds such as styrene, a-methylstyrene and chlorostyrene; vinyl compounds such as acrylonitrile, methacrylonitrile, acrolein and methacrolein; α-olefins such as ethylene and propylene; N-substituted maleimides such as N-methylmaleimide, N-phenylmaleimide and N-cyclohexylmaleimide; acrylamides; vinylpyrrolidones; and (meth)acrylic acid. Also usable are polyfunctional (meth)acrylates such as ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate; and polyfunctional olefins such as divinylbenzene.
[0050] The polymer may be random polymer, graft polymer, block polymer, and hydrogel, although not particularly limited thereto. In whatever form the polymer may be, the characteristic features of the present invention, i.e., the moderate reactivity and hydrophilicity due to the tertiary hydroxyl group, are not lost. The proportion of the monomers is suitably selected depending on the intended use of the polymer. To ensure the effect of the tertiary hydroxyl group, the monomer of Formula 1 is preferably used in an amount of 5 to 100 mol % based on the total monomers. The polymer may be molded or formed into a shaped article or dissolved in a solvent for use as a paint for improving the surface of an article. Also, the polymer may be blended with a known resin.
[0051] The polymer of the present invention may be produced by bulk polymerization by using only the monomers mentioned above and an polymerization initiator, or by solution polymerization, suspension polymerization or emulsion polymerization using an appropriate solvent. Examples of the solvent include alcohols such as methanol, ethanol and isopropyl alcohol; and organic solvents such as THF, DMF, dimethylsulfoxide, toluene and acetone. These solvents may be used alone or in combination of two or more in any proportion. If desired, a chain transfer agent can be used. In addition, an additive such as antioxidants, ultraviolet absorbers, lubricants, fluidity modifiers, releasing agents, antistatic agents and light diffusers; or an inorganic filler such as glass fibers, carbon fibers and clay compounds may be suitably added, if desired.
[0052] The polymer of the present invention is first characterized by simultaneously having a moderate reactivity and a moderate hydrophilicity because of the presence of a tertiary hydroxyl group. Another distinctive characteristic is the absence of an ester linkage derived from a tertiary hydroxyl group. The polymers having a tertiary hydroxyl group which are presently known in the art are synthesized from a pinacol derivative or a hydroxyadamantane derivative to be bonded through an ester linkage derived from a tertiary hydroxyl group. With such a structure, the known polymers release a polyhydric alcohol by heating. This elimination of polyhydric alcohol becomes dominant when the temperature is elevated to 180° C. or higher. Since a resin is molded or formed at over 180° C. in most cases, the elimination of polyhydric alcohol sometimes causes problems such as deterioration of mechanical strength, serious discoloration and molding defect. In contrast, the above problems can be avoided in the polymer produced from the monomer of the present invention because no ester linkage derived from a tertiary hydroxyl group is present therein.
[0053] Since the polymer of the present invention is a functional resin having a moderate reactivity and hydrophilicity, the polymer is used in various applications such as various shaped articles, films, sheets, fibers, pressure-sensitive adhesives, adhesives, paints, artificial marbles, light-guiding plates, optical fibers, foamed articles including shock absorbers and food trays, medical materials including contact lenses, artificial blood vessels, catheter, membranes for blood lavage and dental materials, supports for microorganism, fungus body and pharmacological substances, microcapsules, cosmetic base materials, inks, agents for fiber treatment, agents for paper treatments, agents for wood treatment, materials for reverse osmosis membrane, and various binder resins, although not limited thereto. Various molding aids such as fillers, colorants, reinforcing materials, waxes, thermoplastic polymers and oligomers can be added during the molding or forming process.
[0054] Like a known poly(2-hydroxyethyl methacrylate), the polymer of the present invention is suitable for use as a hydrogel in which the polymer retains water therein. The hydrogel is prepared by a known method. The water content largely depends on the type and the content of comonomer, and can be regulated within a desired range. A hydrogel having a water content of 10 to 90% by weight is most generally used in wide applications such as contact lenses, supports for fungus body, microorganisms and pharmacological substances, metal collectors, and cosmetic base materials.
[0055] The polymer of the present invention has a moderate hydrophilicity, and therefore, provides a surface excellent in biocompatibility when the surface that contacts living body or blood directly is constituted by the polymer. Regarding the blood compatibility, it has been recognized that a material becomes more antithrombotic with the increase of hydrophobicity because a hydrophobic material such as silicone hardly forms thrombus. It has been afterward found that the interfacial energy between a surface and blood is reduced by grafting hydrophilic polymer chains to the surface, thereby decreasing the interaction of the surface with proteins or cells. Thus, a hydrophilic surface also prevents the adhesion of thrombus. However, in some cases, a hydrophilic surface causes minute thrombus to form embolism, damages circulating platelet, causes calcium ion deposit, or triggers the formation of thrombus.
[0056] Therefore, it is important for a medical material to be suitably balanced in hydrophilicity, hydrophobicity and biocompatibility. It is generally acknowledged that a surface having a static contact angle of 30 to 70° with 25° C. water is excellent in biocompatibility. The polymer produced from the monomer of the present invention is useful because the static contact angel with 25° C. water is 30 to 80°. In addition, since the polymer of the present invention is less soluble to water as compared with a known typical hydrophilic polymer, poly(2-hydroxyethyl (meth)acrylate), the polymer is hardly dissolved into a contact aqueous medium, hardly spoils the surface appearance and hardly reduces the mechanical strength.
[0057] The polymer of the present invention has a moderate reactivity. Therefore, if it is used as a polyol component of various types of paints, particularly as a polyol component of an isocyanate hardening paint, the pot life of the paint can be controlled to a desired level by suitably adjusting the content of the tertiary hydroxyl group. Since the rate of hardening reaction can be also controlled, the surface of paint coating can be made smooth. Although not particularly limited, the polymer for use as a polyol component of paints generally has a number average molecular weight of 1000 to 100000 when calibrated by polystyrene standard and a hydroxyl value of 50 to 300 mgKOH/g. The use of a polymer having a content of tertiary hydroxyl group to the total hydroxyl group of 5 to 100 mol % is preferred because the prolongation effect for pot life and the surface smoothing effect due to the reactivity of tertiary hydroxyl group are enhanced.
[0058] The present invention will be explained in more detail by reference to the following example which should not be construed to limit the scope of the present invention.
(I) Synthesis of Vinyl-Polymerizable Monomer
EXAMPLE 1
[0059] Into a 1000-mL reactor equipped with a stirrer, a fractionating condenser, a thermometer and a gas inlet, were charged 500 g of methyl methacrylate (MMA), 222 g of 2-methyl-1,2-propanediol, 3.6 g of sodium methoxide and 0.72 g of hydroquinone. By blowing air into the mixture at 20 mL/min, the reaction was allowed to proceed at 80 to 100° C. for 6 h while distilling away the generated methanol. The removal of methanol was continued at 200 to 150 mmHg for 8 h, and then the pressure was further reduced gradually to remove methanol and the unreacted methyl methacrylate by distillation.
[0060] The liquid residue was rectified under reduced pressure to obtain 375 g of a colorless transparent liquid. By GC-MAS (gas chromatography-mass spectrometry), 1 H-NMR and 13 C-NMR, the product was identified as 2-hydroxy-2-methylpropyl methacrylate. 1 H-NMR spectra and 13 C-NMR spectra are respectively shown in FIGS. 1 and 2 together with assignment of peaks.
EXAMPLE 2
[0061] Into a 500-mL reactor equipped with a stirrer, a fractionating condenser, a thermometer and a gas inlet, were charged 172 g of methacrylic acid, 180 g of IBG, 1.76 g of zinc chloride and 0.35 g of 2,6-di-tert-butyl-p-cresol. By blowing air into the mixture at 20 mL/min, the reaction was allowed to proceed at 80 to 100° C. for 6 h while distilling away the generated water. The removal of water was continued at 200 to 150 mmHg for 5 h, and then the pressure was further reduce gradually to further remove water by distillation.
[0062] To the liquid residue, 3.52 g of a catalyst adsorbent (Mizuka Life P-1 manufactured by Mizusawa Kagaku Kogyo Co., Ltd.). The mixture was stirred for 30 min, cooled to room temperature, and filtered to obtain 200 g of 2-hydroxy-2-methylpropyl methacrylate as a colorless transparent liquid.
EXAMPLE 3
[0063] Into a 500-mL reactor equipped with a stirrer and a thermometer, were charged 59.1 g of 2-methyl-2,4-pentanediol, 52.3 g of triethylamine and 150 mL of methylene chloride. The mixture was kept at 15° C. under stirring in a water bath. Then, 56.0 g of methacryloyl chloride was added dropwise over 15 min and then the stirring was continued for 8 h at 15 to 25° C. After the reaction was completed, the reaction liquid was separated into aqueous layer and organic layer by adding water. The organic layer was sequentially washed with a 5% aqueous sodium hydroxide solution, a 5% hydrochloric acid, and water. After drying the organic layer over anhydrous magnesium sulfate, the solvent was removed by distillation under reduced pressure to obtain 75.7 g of a colorless transparent liquid, which was then purified by a column chromatography. By GC-MAS, 1 H-NMR and 13 C-NMR, the product was identified as 3-hydroxy-1,3-dimethylbutyl methacrylate. 1 H-NMR spectra and 13 C-NMR spectra are respectively shown in FIGS. 3 and 4 together with assignment of peaks.
EXAMPLE 4
[0064] Into a 500-mL flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, were charged 172 g of methacrylic acid, 0.24 g of Antage W-400 (product of Kawaguchi Kagaku Kogyo Co., Ltd.) and 2.4 g of iron(III) hydroxide. The mixture was stirred at 50° C. under heating while blowing air at 10 mL/min. From the dropping funnel, 144 g of isobutylene oxide was gradually added dropwise to the flask over 2 h. The stirring was further continued for 5 h at 60° C. under heating. The gas chromatographic analysis of the reaction liquid showed that the conversion of isobutylene oxide was 95% and the selectivity of 2-hydroxy-2-methylpropyl methacrylate was 90%. After the reaction was completed, the reaction liquid was subjected to phase separation by adding 158 g of cyclohexane and 32 g of a 2 wt % aqueous sodium carbonate to extract the target compound into the organic layer and extract the catalyst and the unreacted methacrylic acid into water layer. By removing the cyclohexane solvent under reduced pressure, 2-hydroxy-2-methylpropyl methacrylate was isolated.
EXAMPLE 5
[0065] The procedure of Example 1 was repeated except for using 430 g of methyl acrylate in place of 500 g of MMA. By GC-MAS, 1 H-NMR and 13 C-NMR, the product was identified as 2-hydroxy-2-methylpropyl acrylate. 1 H-NMR spectra and 13 C-NMR spectra are respectively shown in FIGS. 5 and 6 together with assignment of peaks.
EXAMPLE 6
[0066] The procedure of Example 3 was repeated except for using 48.5 g of acryloyl chloride in place of 56 g of methacryloyl chloride. The reaction product was purified by a column chromatography. By GC-MAS, 1 H-NMR and 13 C-NMR, the product was identified as 3-hydroxy-1,3-dimethylbutyl acrylate. 1 H-NMR spectra and 13 C-NMR spectra are respectively shown in FIGS. 7 and 8 together with assignment of peaks.
EXAMPLE 7
[0067] The procedure of Example 1 was repeated except for using 257 g of 3-methyl-1,3-butanediol in place of 222 g of IBG. By GC-MAS, 1 H-NMR and 13 C-NMR, the product was identified as 3-hydroxy-3-methylbutyl methacrylate. 1 H-NMR spectra and 13 C-NMR spectra are respectively shown in FIGS. 9 and 10 together with assignment of peaks.
EXAMPLE 8
[0068] The procedure of Example 1 was repeated except for using 257 g of 3-methyl-1,3-butanediol in place of 222 g of IBG, and 430 g of methyl acrylate in place of 500 g of MMA. By GC-MAS, 1 H-NMR and 13 C-NMR, the product was identified as 3-hydroxy-3-methylbutyl acrylate. 1 H-NMR spectra and 13 C-NMR spectra are respectively shown in FIGS. 11 and 12 together with assignment of peaks.
(II) Polymer of Vinyl-Polymerizable Monomer Having Tertiary Hydroxyl Group
EXAMPLE 9
[0069] Into a 200-mL glass reactor equipped with a stirrer, a condenser and a thermometer, were charged 60 g of 2-hydroxy-2-methylpropyl methacrylate (HBMA) as a monomer, 0.12 g of dodecanethiol (DSH) as a chain transfer, 0.3 g of 2,2′-azobis(2-methylbutyronitrile) (ABN-E) as a polymerization initiator, and 60 g of methanol as a solvent. The polymerization was allowed to proceed at 65° C. for 3 h under stirring. The polymerization liquid was dropped into diisopropyl ether to precipitate the polymer, which was then vacuum-dried. The polymerization proceeded uniformly, and the polymer thus obtained completely dissolved in an organic solvent such as methanol, acetone and THF.
[0070] The yield of the polymer was determined gravimetrically. The molecular weight was determined by a gel permeation chromatography (GPC) using THF as the developing solvent while calibrated by polystyrene standard. The contact angle as an index of hydrophilicity of the polymer was measured by a contact angle analyzer (CA-X Model manufactured by Kyowa Kaimen Kagaku Co., Ltd.). The sample was prepared by casting a polymer solution in ethanol/THF mixed solvent on a glass plate and then drying. The results are shown in Table 1.
EXAMPLE 10
[0071] Polymer was prepared in the same manner as in Example 9 except for using a monomer mixture of 39.5 g of HBMA and 25 g of MMA. The results are shown in Table 1.
EXAMPLE 11
[0072] Polymer was prepared in the same manner as in Example 9 except for using a monomer mixture of 25 g of HBMA and 37 g of MMA. The results are shown in Table 1.
EXAMPLE 12
[0073] Polymer was prepared in the same manner as in Example 9 except for using a monomer mixture of 8.8 g of HBMA and 50 g of MMA. The results are shown in Table 1.
EXAMPLE 13
[0074] Polymer was prepared in the same manner as in Example 9 except for using a monomer mixture of 4.5 g of HBMA and 54 g of MMA. The results are shown in Table 1.
COMPARATIVE EXAMPLE 1
[0075] Polymer was prepared in the same manner as in Example 9 except for using 50 g of MMA as the monomer and toluene as the solvent. The results are shown in Table 1.
COMPARATIVE EXAMPLE 2
[0076] Polymer was prepared in the same manner as in Example 9 except for using 50 g of 2-hydroxyethyl methacrylate (HEMA) as the monomer. The results are shown in Table 1.
COMPARATIVE EXAMPLE 3
[0077] Polymer was prepared in the same manner as in Example 9 except for using a monomer mixture of 32.5 g of HEMA and 25 g of MMA. The results are shown in Table 1.
COMPARATIVE EXAMPLE 4
[0078] Polymer was prepared in the same manner as in Example 9 except for using a monomer mixture of 21 g of HEMA and 37.7 g of MMA. The results are shown in Table 1.
COMPARATIVE EXAMPLE 5
[0079] Polymer was prepared in the same manner as in Example 9 except for using a monomer mixture of 7.5 g of HEMA and 52 g of MMA. The results are shown in Table 1.
TABLE 1 Examples 9 10 11 12 13 Ratio of charged monomers (mol %) MMA 0 50 70 90 95 HBMA 100 50 30 10 5 Yield (wt %) 78 72 48 55 68 Molecular weight (×10000) 15 10 12 10 10 Contact angle (°) 60 62 65 67 69 Comparative Examples 1 2 3 4 5 Ratio of charged monomers (mol %) MMA 100 0 50 70 90 HBMA 0 100 50 30 10 Yield (wt %) 67 77 56 53 62 Molecular weight (×10000) 10 —* 6.1 10 9.0 Contact angle (°) 72 60 61 65 68
(III) Preparation of Hydrogel
EXAMPLE 14
[0080] A uniform mixture of 8.3 g of HBMA and 0.5 g of ethylene glycol dimethacrylate (EGDMA) was added with 0.1 g of ABN-E. The resultant mixture was placed into a polypropylene tubular container with 20 mm inner diameter.
[0081] After deaerating under reduced pressure, the polymerization was allowed to proceed for 4 h in a 40° C. water tank. The polymerization was further continued for 4 h at 50° C., for 4 h at 60° C. under heating, and then the temperature was gradually raised in a dryer from 60° C. up to 130° C. over 12 h, thereby obtaining a rod-shape polymer with about 20 mm diameter.
[0082] The rod-shape polymer was cut into a test specimen. The weight (W 0 g) of the test specimen in equilibrium condition on water-absorbing and the weight (W 1 g) of a dried test specimen were measured to calculate the water content (wt %) from the following equation:
Water content (wt %)=[( W 0 −W 1 )/ W 0 ]×100.
[0083] The result is shown in Table 2.
EXAMPLES 15 to 18 and COMPARATIVE EXAMPLES 6 to 10
[0084] Each rod-shape polymer was prepared in the same manner as in Example 14 except for changing the molar ratio of the methacrylate mixture as shown in Table 2. The water content of each test specimen prepared in the same manner is shown in Table 2.
TABLE 2 Examples 14 15 16 17 18 Ratio of charged methacrylates (mol %) MMA 0 49 0 0 0 HEMA 0 0 49 69 89 HBMA 99 50 50 30 10 EGDMA 1 1 1 1 1 Water content (wt %) 26 12 32 34 37 Comparative Examples 6 7 8 9 10 Ratio of charged methacrylates (mol %) MMA 0 49 69 10 99 HEMA 99 50 30 89 0 HBMA 0 0 0 0 0 EGDMA 1 1 1 1 1 Water content (wt %) 39 19 10 35 2
(TV) Synthesis of Coating Resin Having Tertiary Hydroxyl Group
EXAMPLE 19
[0085] Into a 5000-mL reactor equipped with a stirrer, a condenser and a thermometer, were charged 1600 g of xylene and 400 g of butyl acetate. After raising the temperature to 85° C., the polymerization was allowed to proceed by adding dropwise over 3 h a mixture of 500 g of styrene, 500 g of methyl methacrylate, 280 g of n-butyl acrylate, 420 g of n-butyl methacrylate, 86 g of 2-hydroxy-2-methylpropyl methacrylate, 168 g of 2-hydroxyethyl methacrylate, 14 g of acrylic acid, and 24 g of α,α′-azobisisobutyronitrile. After the dropwise addition, the stirring was continued for 2 h under heating. The stirring was further continued for 3 h under heating by adding 10 g of α,α′-azobisisobutyronitrile. By evaporating off the solvent, was obtained 1830 g of a coating resin A having a hydroxyl value of 52 mgKOH/g and an acid value of 6 mgKOH/g.
[0086] A varnish A was prepared by blending 75 parts by weight of the coating resin A and 25 parts by weight of toluene.
COMPARATIVE EXAMPLE 11
[0087] A coating resin B (1770 g) having a hydroxyl value of 52 mgKOH/g and an acid value of 5 mgKOH/g was prepared in the same manner as in Example 19 except for changing the mixture of monomers and polymerization initiator being added dropwise to a mixture of 500 g of styrene, 400 g of methyl methacrylate, 380 g of n-butyl acrylate, 420 g of n-butyl methacrylate, 240 g of 2-hydroxyethyl methacrylate, 14 g of acrylic acid, and 24 g of α,α′-azobisisobutyronitrile.
[0088] A varnish B was prepared by blending 75 parts by weight of the coating resin B and 25 parts by weight of toluene.
[0089] Each enamel paint was prepared by blending the ingredients in the proportions shown in Table 3. Specifically, a rutile titanium dioxide pigment (CR-90, product of Ishihara Sangyo Co., Ltd.) was dispersed in the varnish A or B. The dispersion was further added with a hardening agent (DN-980, product of Dainippon Ink & Chemicals, Inc.) and a leveling agent (BYK-301, product of BYK-chemie Japan Co., Ltd.) to prepare an enamel paint. The enamel paint was coated by a doctor blade on a chemically treated steel plate in a thickness of 15 to 20 μm. The results of evaluation on the coating film are shown in Table 3.
TABLE 3 Comparative Example 19 Example 11 Composition of paint (part by weight) Varnish type A B amount 57.2 57.2 CR-90 31.3 31.3 DN-980 11.0 11.0 BYK-30 0.5 0.5 Pot life (h) 1.0 0.3 60° Specular gloss (%) 92 92 Erichsen value (mm) >7 >7 Pencil hardness H H Rubbing test good good
[0090] The evaluations were made as follows.
[0091] Hydroxyl value: Measured according to JIS K-0070.
[0092] Acid value: Measure according to JIS K-8400.
[0093] Pot life: Time taken after the solution containing a coating resin was mixed with a hardening agent until the viscosity reached twice the initial viscosity was measured.
[0094] 60° Specular gloss: Measured according to JIS K-5400.
[0095] Erichsen value: Measured according to JIS K-5400.
[0096] Pencil hardness: Measured according to JIS K-5400.
[0097] Rubbing test: After rubbing 100 times the surface of paint film with gauze impregnated with toluene, the surface was visually observed. The result was rated as “good” when no change was noticed, and “poor” when the paint film was partially dissolved.
[0098] As seen from the results, by using the tertiary hydroxyl group-containing monomer of the present invention as a starting material for varnish, the pot life, as compared with using known monomers, is prolonged three times or more with the paint film performance retained.
[0099] In the present invention, the novel vinyl-polymerizable monomer of Formula 1 having a vinyl-polymerizable group X and a tertiary hydroxyl group is prepared by the reaction of a compound for introducing the vinyl-polymerizable group X and a compound for introducing the tertiary hydroxyl group. With a moderate hydrophilicity and reactivity of the monomer, a polymer produced by the copolymerization of the monomer and other vinyl comonomers is used in various applications such as various shaped articles, films, sheets, fibers, pressure-sensitive adhesives, adhesives, paints, artificial marbles, light-guiding plates, optical fibers, foamed articles including shock absorbers and food trays, medical materials including contact lenses, artificial blood vessels, catheter, membranes for blood lavage and dental materials, supports for microorganism, fungus body and pharmacological substances, microcapsules, cosmetic base materials, inks, agents for fiber treatment, agents for paper treatments, agents for wood treatment, materials for reverse osmosis membrane, and various binder resins.
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The monomer of the present invention is represented by the following Formula 1:
wherein X, R 1 to R 3 , and m are as defined in the disclosure. The monomer is structurally characterized by the presence of a tertiary hydroxyl group and a vinyl-polymerizable group X and the absence of an ester linkage derived from a tertiary hydroxyl group. Polymers produced by the polymerization of the monomer and an optional comonomer have a moderated reactivity and hydrophilicity.
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CROSS REFERENCE TO A RELATED APPLICATION
This application is a Continuation in Part of International Application No. PCT/CN04/000742 filed Jul. 5, 2004, the contents of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The invention is in the field of genetic engineering, specifically relates to expression vectors controlled by a sigma factor σ 32 of Escherichia coli , and methods of expression of target genes using the vectors.
BACKGROUND OF THE INVENTION
In molecular biotechnology and bioengineering, the production of recombinant protein is achieved by cloning the target gene into an expression vector, and introducing the recombinant vector into corresponding host such as bacterium, yeast, plant or animal cells, where the target gene is expressed. Bacterial host E. coli is often the first choice for the expression of many recombinant proteins, because it is easy, fast and inexpensive to cultivate, and its vector systems have been well developed. To reach a high level of expression in E. coli , the foreign gene is usually under the control of a regulatory promoter, which plays important roles in reducing the adverse effects of recombinant protein on host cells, decreasing the degradation of target protein by cellular protease of the host cells, and increasing the production of active recombinant protein. Using promoters of different sources, many E. coli expression vector systems have been developed in the last 20 years, and the best known vectors are those containing lac promoter and its hybrids, the bacteriophage λ p L promoter and T7 promoter, which are respectively identified as the lac/tac/trc system, the p L system and the T7 system (Sambrook, J, and D W Russell. 2001. Molecular Cloning: a laboratory manual, 3rd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.).
The lac/tac/trc system. In this expression system, vectors carry the lac promoter, or its hybrid tac or trc promoter. Under the control of one of these promoters, the transcription initiation of target gene is repressed by the repressor of lac opron in the absence of lactose or its analogues such as isopropyl-β-D-thiogalactopyranoside (IPTG). In both experimental and commercial production settings, the expression of target genes is induced by adding IPTG or lactose as the inducing agent into the culture of E. coli harboring vectors of the lac/tac/trc system, wherein the inducing agent releases the repressor and allows transcription to initiate. However, the high cost and toxicity of IPTG limites its wide use for the production of proteins for medical and many industrial applications. Lactose is cheaper than IPTG as inducing agent, but is not as effective as the latter because it can be metabolized.
The p L system. In bacteriophage λ, the early transcription promoters p L and p R are regulated by a repressor encoded by the cI gene. The p L has been used in expression vectors to control the expression of target genes via the gene product of cIts857, which is a temperature sensitive mutant of cI. In cells harboring these vectors, the repressor binds to p L and represses the transcription of target gene at low temperatures but not at elevated temperatures, and thus gene expression is induced by raising the temperature of a culture (Elvin C M, P R Thompson, M E Argall et al. 1990. Modified bacteriophage lambda promoter vectors for overproduction of proteins in Escherichia coli . Gene, 87: 123-126). However, because an effective induction requires rapidly raising the temperature from about 30° C. to 40° C., there is difficulty in the application of the p L system for large-scale cultures in industrial settings (Glazer, A N, and H Nikaido. 1995. Microbial Biotechnology. WH Freeman and Company, New York).
The T7 system. In this system, the bacteriophage T7 promoter is used in vectors to control the expression of target gene, and the transcription is specifically performed by T7 RNA polymerase. The gene encoding T7 RNA polymerase has been integrated in the chromosome of host cells under the control of lac or p L promoter, and its expression is induced by IPTG or temperature shift. The bacteriophage T7 promoter is the strongest among all the promoters used in E. coli expression systems, but growth inhibition or inclusion body formation sometimes are associated with high expression levels [Russell D. 1999. Gene expression systems based on bacteriophage T7 RNA polymerase. In Gene Expression Systems (Fernandez, J M, and J P Hoeffler, eds.), pp 9-44. Academic Press, London]. Meanwhile, the T7 system faces the same problems as other systems in inducing agents or raising temperatures.
The heat shock system of E. coli . When E. coli is subjected to a quick rise of temperature, an alternative sigma factor (σ 32 , encoded by the rpoH gene) recognizes the so-called heat-shock promoters of a group of heat-shock protein-encoding genes, resulting in the expression of heat-shock proteins. The DNA sequences of heat-shock promoters have been known, and their consensus sequences are different from that of the general promoters recognized by the σ 70 (Miller, J H. 1992. A Short Course in Bacterial Genetics, Handbook. Cold Spring Harbor Laboratory Press, New York) (Turner, P C T, A G McLennan, A D Bates, and M R H White. 1997. Instant Notes in Molecular Biology, BIOS Scientific Publishers, UK). The differences of the two consensus sequences are shown below.
General promoters:
(SEQ ID NO: 11)
----------- TTGACA -16~18 bp- TATAAT
Heat-shock promoters:
(SEQ ID NO: 12)
--C-C-C TTGAA -13~15 bp-CCCUCAT-T
Although the heat-shock system in E. coli has been well understood for its physiological functions and regulatory mechanisms, prior to the present invention, heat-shock promoters have never been used effectively as promoters to regulate the expression of foreign genes in plasmid vectors. This may be due to the fact that the heat-shock reaction lasts (i.e. the heat-shock system shuts down, and the cell is back to its normal state within 20 min) only 20 minutes after E. coli is subjected to an increase in temperature. Commercial application of this system may have also been discouraged by the apparent difficulty in quickly raising the temperature of large volume of culture medium, as in the case of using p L system.
SUMMARY OF THE INVENTION
The present invention provides an expression vector comprising promoters which are recognized and regulated by a heat shock sigma factor of Escherichia coli . Preferably, the heat shock sigma factor of E. coli is σ 32 . An expression vector of the present invention preferably comprises a promoter that comprises the consensus sequence of bacterial heat shock promoters, especially that depicted as SEQ ID NO: 1.
In one embodiment, an expression vector of the present invention further comprises a polynucleotide sequence encoding a target polypeptide sequence under the control of the promoter. The expression vector according to the present invention is more preferably a plasmid vector, such as the pHsh vector shown in FIG. 1 .
The present invention in another embodiment provides a method for producing a target polypeptide, the method comprising (1) providing bacterial cells harboring an expression vector which comprises a polynucleotide sequence encoding the polypeptide under the control of a promoter that is recognized by a heat shock sigma factor of Escherichia coli , and (2) cultivating the bacterial cells under conditions that induce the expression of the polynucleotide sequence in the vector. The bacterial cells are preferably E. coli cells. In one embodiment, the bacterial cells are subject to a temperature shift, or a heat shock.
The present invention further provides a method for creating a sudden temperature shift or heat shock in a cell culture, the method comprising: (1) providing a fermentor A and a fermentor B, wherein a heating rate for fermentor B is known, wherein the heating rate is defined as a time period needed for heating up a unit volume of cultural medium from about 30° C. to about 42° C., (2) cultivating cells of interest in a suitable amount of medium in fermentor A at 27° C.˜35° C., (3) maintaining a suitable amount of cultural medium in fermentor B at about 37° C.˜44° C.; (4) introducing medium in fermentor A alone with cells at suitable growth stage to fermentor B at a rate corresponding to the heating rate for fermentor B, wherein a unit volume of cultural medium is introduced to fermentor B per time period, while fermentor B is being heated at the heating rate; and (5) continuing to culture the cells in fermentor B at about 37° C.˜44° C. The cells are preferably E. coli cells and a heat shock reaction is induced in the cells upon introduction from Fermentor A to Fermentor B. In preferred embodiments, the cells comprise an expression vector which comprises a promoter that is recognized and regulated by a heat shock sigma factor and a polynucleotide sequence encoding a polypeptide sequence under the control of the promoter, and wherein the polypeptide is expressed upon the induction of the heat shock reaction. Preferably, prior to step (4) above, the volume of cultural medium in fermentor B is between about 1/10 and equal amount of cultural medium in Fermentor A. A small amount of medium in fermentor B is preferred to ensure that the newly introduced cultural medium from fermentor A is quickly brought to the high temperature desired, and excessive volume in fermentor B prior to introduction of medium from fermentor A should be avoided such that the cells from the fermentor A not be too much diluted. Preferably, the immediately after step (4), cell density in fermentor B is about 10%˜20% of the highest cell density reachable under the nutrient, aeration and other cultural conditions. Under these circumstances, the cells are cultured in fermentor B for an additional 6˜9 h at 40° C.˜42° C. after step (4) above so as to achieve maximum level of production for the target protein.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1(A) depicts the structure of pHsh. The restriction sites listed in pHsh are unique for the respective endonucleases. FIG. 1(B) shows the nucleotide sequence of the regulatory region in pHsh. (SEQ ID NO:10)
FIG. 2 shows the expression level of arabinofuranosidase and cell density of E. coli cells harboring different vectors at different time. The LB medium used contains the following antibiotics: for pHsh-xar, and pTrc99A-xar, ampicillin, 100 μg/ml; and for pET-xar kanamycin, 30 μg/ml; a unit of arabinofuranosidase activity is defined as follows: using 1 mM p-Nitrophenyl-α-L-arabinopyranoside (pNPA, sigma) as substrate, one unit of arabinofuranosidase activity is the amount of enzyme that catalyzes the production of 1 μmol of p-nitrophenol (pNP) in one minute under the conditions of 80° C. & pH=5.7.
FIG. 3 shows the expression level of xylanase and cell density of E. coli cells harboring different vectors at different time. The LB medium used contains the following antibiotics: for pET-xynIII, kanamycin at 30 μg/ml; and for pJLA503-xynIII, and pHsh-xynIII, ampicillin at 100 μg/ml. One unit of xylanase activity is defined as the amount of enzyme that catalyzes the production of 1 μmol of reducing sugar using 0.5% xylan from oat spelts as substrate in one minute under the conditions of 90° C. & pH=5.8.
DETAILED DESCRIPTION OF THE INVENTION
In one embodiment, the present invention provides a novel expression system for example of plasmid vectors, containing heat-shock promoters, in which the over-expression of target genes is regulated by σ 32 . In another embodiment, the present invention provides a method of perform heat-shock induction of target gene expression, especially at the fermentor-scale by using the novel vectors.
Some of the preferred embodiments of the present invention are provided below:
1. A series of plasmid vectors or a vector system with promoters recognized and regulated by σ 32 of Escherichia coli . These vectors are designated as Hsh expression system.
2. Vectors described in ‘1’, containing a promoter designed on the basis of the consensus sequence of heat-shock promoters, and regulated by σ 32 . The preferred sequence of this promoter comprises 5′- CCCCC TTGAA TGTGG GGGAA ACAT C CCCAT GA T CC AAGGAG-3′ (SEQ ID NO:1).
3. Vectors as described in ‘1’ carrying one of heat-shock promoters from heat-shock protein-encoding genes of E. coli . The promoter sequences in these vectors include 5′-CGGCG TTGAA TGTGG GGGAA ACATC CCCAT ATACT GACGT-3′ (SEQ ID NO:2) for lon gene, or 5′-CCCCC TTGAT GACGT GGTTT ACGAC CCCAT TTAGT AGTCA-3′ (SEQ ID NO: 3) for dnaKP1 gene.
4. Recombinant plasmids constructed by inserting any polypeptide-encoding gene into any vector described in ‘1’. A target gene can be inserted into any vector described in ‘1’, ‘2’ or ‘3’.
5. A method for the production of recombinant proteins by using the gene expression vectors described in ‘1’. The procedures include inserting a gene into the vectors to construct recombinant plasmids as described in ‘4’, transforming E. coli cells with constructed plasmids, and then cultivating the transformed cells and inducing the gene expression by a temperature shift.
6. A method for creating a quick temperature shift of the culture to obtain a heat-shock induction of foreign gene expression, which includes following steps:
(1) Providing two fermentors A and B, and determining the heating rate (time need for heating up a unit volume (e.g. a liter) of medium from about 30° C. to about 42° C. in fermentor B (minutes/liter). (2) Adding a suitable amount of medium to fermentor A and B, and controlling the temperature of fermentor A at 27° C.˜35° C., and fermentor B at 37° C.˜44° C. (3) Inoculating the medium in fermentor A with E. coli cells harboring recombinant plasmids, and cultivating at 27° C.˜35° C. with aeration and stirring. (4) When the cells reach early logarithmic phase, transferring the culture from fermentor A into fermentor B at a flow rate (liter/min) that matches the heating rate (min/liter) with continuous heating and stirring. (5) After all the culture is transferred into fermentor B from fermentor A, continuing to cultivate for 2˜12 h at 37° C.˜44° C. The foreign gene is induced to express during this period.
7. The method for heat-shock induction of gene expression as described in 6, wherein
in step (2), the starting volume of the medium in fermentor A and that in fermentor B are in the ratio of 10 to 1; and after autoclave, the temperature is set at 30° C. for fermentor A, and 40° C.˜42° C. for fermentor B,
in step (4), the culture in fermentor A is injected into fermentor B, which is under suitable heating and aeration, whereby the temperature of the culture shifts from 30° C. to 40° C.˜42° C. instantaneously and the cell density (OD 600 ) is about 10%˜20% of the highest reading to be reached under the conditions, and
in step (5), after the culture has been transferred from fermentor A to fermentor B, the cell growth is continued for 6˜9 h at 40° C.˜42° C. to obtain large amount of recombinant proteins.
Advantages of Hsh Expression System
The gene expression in the plasmid vectors of Hsh system employs the regulation mechanism of the heat shock system of E. coli , while other expression systems are directly or indirectly regulated by repressors such as gene products of lacI and cI(ts)857. Although its transcription may not be as strong as bacteriophage promoters, Hsh promoter allows its plasmids to employ a replicon having a very high copy number. The Hsh expression system along with the induction methods of the present invention have at least the following advantages:
1. The expression vectors of Hsh system achieve high recombinant protein yield (U/liter or mg/liter).
2. Gene expression is induced by a temperature shift instead of costly chemical inducing agent such as IPTG, which may contaminate the recombinant protein product.
3. The methods for heat-shock induction allow the production of recombinant proteins in fermentor-scales.
4. The small molecule size of Hsh vectors allows the modification of the sequences of the target gene in situ.
5. There is no special host cell requirement due to gene-type.
EXAMPLES
Example 1
Construction of Hsh Vectors
1. Design of Heat-Shock Promoters and Terminator
Based on the consensus sequence of heat-shock promoters in E. coli , a novel promoter was designed and used in most of Hsh vectors exemplified herein. The nucleotide sequence of this novel promoter comprises 5′-CCCCC TTGAA TGTGG GGGAA ACATC CCCAT GATCC AAGGA G-3′ (SEQ ID NO:4), designated as Hsh promoter ( FIG. 1 ). The promoters of the lon gene and the dnakP1 gene of E. coli were directly used to control the expression of foreign genes in some other Hsh vectors. The nucleotide sequence for the lon promoter is 5′-CGGCG TTGAA TGTGG GGGAA ACATC CCCAT ATACT GACGT-3′ (SEQ ID NO:2), and 5′-CCCCC TTGAT GACGT GGTTT ACGAC CCCAT TTAGT AGTCA-3′ (SEQ ID NO:3) for the dnakP1 promoter.
A ρ independent GAAA terminator was designed for pHsh vectors on the basis of ECORPSRPO of E. coli . Its nucleotide sequence comprises 5′-GAAGG CCGCT TCCGA AAGGA AGCGG CTTTT TT-3′ (SEQ ID NO:5), which was named as Hsh terminator ( FIG. 1 ). Other terminators from E. coli can also be used in these vectors to terminate transcriptions initiated by heat-shock promoters, e.g. the ECORPOC terminator (5′-CGGAC GTCAG GCCGC CAC TT CGGTG CGGTT ACGTC CGGCT TTCTT T-3′) (SEQ ID NO:6) or the ECOXYLE terminator (5′-CTTCC TGTCC AGCAC GCCGC GCCAT TTCGG CGTGC TGACT TTTT-3′) (SEQ ID NO:7).
2. The Amplification and Assembly of DNA Fragments
(1) A pair of primers containing Hsh promoter or terminator were synthesized, the forward primer was 5′-CCGGA ATTCC TCCTT GGATC ATGGG GATGT TTCCC CCACATT CAAGG GGG CT CTTCC GCTTC CTCTC -3′ (SEQ ID NO:8), and the reverse primer was 5′-TGAAG CTTGA AGGCC GCTTC CGAAA GGAAG CGGCT TTTTT GCCTG ATGCG GTATT TTC -3′ (SEQ ID NO:9), where underlined sequences anneal to the template pUC19. The PCR amplification was carried out with DNA polymerase Pyrobest (TaKaRa Biotech, Co., Ltd., Dalian, China), and the resulting fragments contained the replicon and the ampicillin resistance gene from pUC19 in addition to Hsh promoter and terminator.
(2) The xynB gene of Thermotoga maritima (ATCC43589) encoding a xylanase was amplified by PCR with addition of restriction site for BamHI at the 5′ end, and sequences of XhoI, a 6-his-tag, and a restriction site for HindIII at the 3′ end, respectively. The resulting fragments were digested by BamHI and HindIII and inserted into pAlter-ex2 which had been digested by the same restriction enzymes, and the recombinant plasmids obtained from transformed E. coli was designated as pAlter-ex2-xynB.
(3) A fragment containing the SD sequence, multiple cloning sites (MCS), xynB, his-tag sequence was cut out from pAlter-ex2-xynB by EcoRI and HindIII, and ligated to the fragment generated in (1) which had been digested with the same restriction enzymes. The resulting plasmid was designated as pHsh-xynB. The vector pHsh was obtained by removing xynB from pHsh-xynB with BamHI and XhoI, blunting the ends, and re-circulating the plasmids ( FIG. 1 )
The Hsh system of vectors of the present invention may comprise heat-shock promoters other than the Hsh promoter. For example, vector pHsh-lon or pHsh-dk was obtained by substituting the Hsh promoter in pHsh with the heat-shock promoter of gene ion or dnak p1. The procedures included the introduction of substituted sequences by PCR using the DNA polymerase of Pyrobest, phosphorylation and the self-ligation of the fragments.
Example 2
Methods for the Application of Hsh Vectors
1. Cloning and Modification of a Foreign Gene in the Vectors of Hsh System
A target gene suitable for expression using the Hsh system vectors of the present invention should encode a protein that is relatively stable at or above 42° C. Gene manipulation is performed following standard methods described in Molecular Cloning by Sambrook and Russell (2001). In brief, a target gene is amplified by PCR, the PCR products are digested with a proper restriction enzyme(s), ligated to a vector of Hsh system at the MCS, and introduced into E. coli cells. The recombinant plasmids are isolated from the transformed E. coli , and stored in freezers in the presence of 1 mM EDTA for further work.
After a gene is cloned into a vector of the Hsh system, site-directed mutagenesis can be performed in situ because the vector is small enough for reverse PCR using primers containing modified nucleotide sequences. In this case, high fidelity DNA polymerases such as Pyrobest may be employed to produce DNA fragments of blunt ends, which are then phosphorylated and re-circularized without the insertion or deletion of nucleotide. For example, xynB was modified (to remove the signal peptide from xynB and replace some codons which were rare in E. coli ) in pHsh-xynB to generate pHsh-xynIII, which gave an increase of about 68 times in expression level.
2. Induction of Gene Expression in Test Tubes or Shaking-Bottles
In a laboratory setting, the induction of recombinant gene expression is often carried out in test tubes or shaking-bottles. Under these conditions, the expression of foreign gene using vectors regulated by temperature shift is an easy operation and avoids the need for IPTG. Because it requires a quick rise of the temperature for effective induction, in practice, a relatively small volume of culture in a container is recommended for rapid temperature exchanges, e.g. placing 3 ml or less medium in a test tube with a diameter of 16 mm, or less than 30 ml in a 100 ml-flask.
Working Procedures:
(1) Transform E. coli cells with a recombinant plasmid;
(2) Pick single colonies into test tubes or shaking-bottles containing a desired medium;
(3) Incubate with shaking at the low temperature (e.g. 27° C.˜35° C.) to early logarithmic phase. If necessary, inoculate and enlarge the culture before proceeding to the next step;
(4) Induce the gene expression by transferring the test tubes or flasks into a shaking water-bath incubator pre-heated to the high temperature 37° C.˜44° C.; and continue to cultivate for 2˜12 h as desired. Temperature change can also be manually achieved by holding and shaking the test tubes or flasks for about 10 min in a water bath of 37° C.˜44° C. before cultivating in a shaking air-bath incubator at 37° C.˜44° C., and
(5) Harvest cells and isolate the recombinant protein as desired.
3. Induction of Gene Expression in Fermentor-Scales
For heat-shock induction in a larger or bulk volume of culture, this invention provides a method, which is designated “flow-in-heat.” Similarly to the procedure described previously, freshly transformed E. coli cells are used to achieve the best expression level. The principal points of flow-in-heat are as follows:
(1) Take two fermentors A and B, use A at a lower temperature a, and B at a higher temperature b. Before cells are introduced to fermentor B, the time needed for raising temperature of a unit volume of medium in fermentor B from temperature a to b is determined, and the heating rate x (1/min), i.e. the amount of time needed for the temperature of a unit volume, e.g. 1, to be increased from a to b, is calculated. For temperature a, 27° C.-35° C. is recommended with 30° C. being preferred, and 37° C.-44° C. is recommended for temperature b with a preferred range of 40° C.-42° C.
(2) Add a suitable amount (n liters) of medium into fermentor A, and about n×0.1˜1 liters into fermentor B, autoclave, and cool down to the temperature a and b, respectively.
(3) Inoculate fermentor A using E. coli cells carrying a recombinant plasmid of pHsh system, and cultivate with aerating and stirring at temperature a.
(4) When the cells grow to early logarithmic phase in fermentor A, induce gene expression by pumping the culture into fermentor B with a flow rate (1/min) corresponding to the heating rate determined in (1) above. In other words, if fermentor B can increase x liters of medium from temperature a to b per minute, then the flow rate should be adding x liters of medium from a to b per minute, while fermentor B is operating at the heating rate. The cell density in early logarithmic phase is varied with richness of the medium and strength of aeration, and in general the time to start expression induction is recommended at a cell density of about 10%˜20% of the highest density.
(5) After all the culture has been pumped into B from A, continue to cultivate for 2-12 h at temperature b.
(6) Harvest cells and isolate the recombinant protein as desired.
Example 3
Expression of Gene xar or xyn in Vectors of Different Systems
1. Gene Cloning and Expression Assay
The arabinosidase gene xar (GenBank Accession No. AF135015) from Thermoanaerobacter ethanolicus , the xylanase gen xynB (GenBank Accession No. AE001693) from T. maritima , and its mutant xynIII were used as target genes for expression tests. In addition to pHsh, pTrc99A (lac/tac/trc system, Pharmacia, Piscataway, N.J., USA), pET28 (T7 system, Novagen, Inc., Madison, Wis., USA) and pJLA503 (p L system) were used as vectors. The target genes were cloned into the expression vectors using standard methods (Sambrook and Russell, 2001), and recombinant plasmids were constructed and recorded directly with their vector and gene names, which included pHsh-xynB, pHsh-xynIII, pHsh-xar, pET-xynIII, pET-xar, pTrc-xar, and pJLA-xynIII. The plasmids were introduced into E. coli strain JM109 (DE3) (for pET vector), or strain JM109 (for the others) by electroporation.
During the period of cultivation, cell densities were measured by OD 600 — reading, and expression levels determined by enzyme activities. The xylanase activity was determined at 90° C., pH 5.8 using 0.5% xylan (Sigma, from oat spelt) as substrate, and the reducing equivalents released were quantified using p-hydroxybenzoic acid hydrazide (PAHBAH) assay (Lever, M. 1972. A new reaction for colorimetric determination of carbohydrates. Anal. Biochem. 47: 273). The arabinosidase activity was determined at 80° C. and pH 5.7 using p-nitrophenyl α-arabinofuranoside as substrate, and catalytic product, p-nitrophenol was quantified by reading absorbance at 405 nm after adding 2× volume of 1 M Na 2 CO 3 into the reaction mixture. One unit of enzyme activity was defined as the amount of the enzyme to produce 1 μmol of products in a minute.
2. Induction of Xylanase Gene Expression by Flow-in-Heat
In a 15-liter fermentor, 10 liters of Terrific medium was cooled to 30° C. after autoclave, another 10 liter medium was in a 25-liter fermentor automatically controlled at 42° C., and 0.8 g of ampicillin was added into each fermentor. To the 15-liter fermentor, an inoculum of 250-ml culture of E. coli harboring pHsh-xynB was injected into its medium, and cells were grown aerobically at 250 rpm at 30° C. to OD 600 =1.2. Then the culture was transferred into the 25-liter fermentor at a rate of 1 liter per min, where the temperature was kept at the level of 39° C.˜42° C. by heating and stirring. The cultivation was continued aerobically at 42° C. after all the culture in the 15-liter fermentor was transferred into 25-liter fermentor, and cell density and xylanase activity were monitored every hour. The cells were harvested by centrifuge after 6 hours when the xylanase activity was about 240,000 U per liter of culture.
3. Expression in Shaking-Bottles
Expression of pHsh-xar, pHsh-xynIII and pJLA-xynIII was induced by heat shock as follows. Overnight cultures of E. coli carrying the above plasmids were inoculated into 30 ml of Terrific media containing 0.1 mg/ml of ampicillin in a 100-ml flask, and the cells were grown at 30° C. in a shaking incubator. When the cell density (OD 600 ) reached about 1.0, the flask was transferred into a water bath shaker of 42° C., in which cell growth was continued and gene expression is induced for up to 9 h. The expression of genes in pET-xar, pET-xynIII, or pTrc-xar was induced by adding IPTG to 1 or 5 mM according to manufacture's instructions.
The expression levels were compared by arabinosidase activities in E. coli harboring pHsh-xar, pET-xar, and pTrc-xar, and by xylanase activities in cells harboring pHsh-xynIII, pET-xynIII, and pJLA-xynIII. The results showed that the arabinosidase activity produced by pHsh-xar was 3.6 and 1.5 times higher than that by pTrc-xar and pET-xar ( FIG. 2 ), and the xylanase activity produced by pHsh-xynIII was 10 and 2.4 times higher than that by pET-xynIII and pJLA-xynIII ( FIG. 3 ), respectively.
Examples 4-20
The following experiments were conducted using the vector(s), induction methods and target genes and host strains as described above in Examples 1-3, except otherwise and specifically noted.
Example 4
The host cell used was E. coli strain K12.
Example 5
The difference consisted in the method of induction. Here, the recombinant cells were cultivated aerobically in a shaker at 30° C. After the cell density reached an OD 600 of 0.8, the test tubes (or flasks) were transferred into the water-bathed shaker from 30° C. to 42° C., and continued to cultivate for 7 h.
Example 6
The difference consisted in the method of induction. Here, recombinant pHsh-xar cells were cultivated aerobically in a shaker at 30° C. After the cell density reached an OD 600 of 0.8, the cells were harvested by centrifugation, and removed the supernatant, the cell pellets were inoculated to the media which had been preheated to 40° C., and continued to cultivate for 8 h at 40° C.
Example 7
The difference consisted in the procedure of expression. Here, after autoclave, the temperature in fermentor A was decreased to 28° C., and the cells were cultivated to an OD 600 of 0.4. After autoclave, the temperature in fermentor B with 1 L sterile Terrific media was decreased to 37° C. When the cells grew to early logarithmic phase in fermentor A, induced gene expression by pumping the culture into fermentor B with a flow rate of 1 L/min. All the culture had been pumped into B from A, continued to cultivate for 2 h at 37° C.
Example 8
The difference consisted in the procedure of expression. Here, after autoclave, the temperature in fermentor A was decreased to 32° C., and the cells were cultivated to an OD 600 of 0.5. After autoclave, the temperature in fermentor B with 5 L sterile Terrific media was decreased to 44° C. When the cells grew to early logarithmic phase in fermentor A, induced gene expression by pumping the culture into fermentor B with a flow rate of 1 L/min. All the culture had been pumped into B from A, continued to cultivate for 10 h at 44° C.
Example 9
The difference consisted in the procedure of expression. Here, after autoclave, the temperature in fermentor A was decreased to 29° C., and the cells were cultivated to an OD 600 of 0.9. After autoclave, the temperature in fermentor B with 8 L sterile Terrific media was decreased to 41° C. When the cells grew to early logarithmic phase in fermentor A, induced gene expression by pumping the culture into fermentor B with a flow rate of 1 L/min. All the culture had been pumped into B from A, continued to cultivate for 9 h at 37° C.
Example 10
The difference consisted in the procedure of expression. Here, after autoclave, the temperature in fermentor A was decreased to 31° C., and the cells were cultivated to an OD 600 of 0.7. After autoclave, the temperature in fermentor B with 2 L sterile Terrific media was decreased to 40° C. When the cells grew to early logarithmic phase in fermentor A, induced gene expression by pumping the culture into fermentor B with a flow rate of 1 L/min. All the culture had been pumped into B from A, continued to cultivate for 12 h at 40° C.
Example 11
The difference consisted in the procedure of expression. Here, there were 15 L media in fermentor A, and there were 20 L media in fermentor B.
Example 12
The difference consisted in the procedure of expression. Here, there were 20 L media in fermentor A, and there were 15 L media in fermentor B.
Example 13
The difference consisted in the heating rate. Here, the heating rate in fermentor B was 1.2 L/min.
Example 14
The difference consisted in the opportunity of induction. Here, the induction is carried out when the cell density in fermentor A reached an OD 600 of 3.0.
Example 15
The difference consisted in the opportunity of induction. Here, the induction is carried out when the cell density in fermentor A reached an OD 600 of 0.7.
Example 16
The difference consisted in the opportunity of induction. Here, the induction is carried out when the cell density in fermentor A reached an OD 600 of 2.2.
Example 17
The difference consisted in the media which was used. Here, the cultivation was carried out in Luria-Bertani media.
Example 18
The difference consisted in the opportunity of induction. Here, the induction is carried out when the cell density in fermentor A reached an OD 600 of 2.0.
Example 19
The difference consisted in the opportunity of induction. Here, the induction is carried out when the cell density in fermentor A reached an OD 600 of 0.6.
Example 20
The difference consisted in the opportunity of induction. Here, the induction is carried out when the cell density in fermentor A reached an OD 600 of 0.9.
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This invention discloses an expression vector system comprising a promoter recognized and regulated by a heat shock sigma factor of E. coli , especially σ 32 . Preferably, the promoter comprises the consensus sequence of E. coli heat shock promoters as shown in SEQ ID NO:1. Also disclosed are methods for producing proteins using the promoter under heat shock conditions. Furthermore, the present invention discloses a method for creating a sudden temperature shift in a cell culture which has been pre-cultured to reach an optimal condition and which temperature shift will allow optimal production of a recombinant protein under the control a heat shock promoter.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method and apparatus for forming a non-Gaussian interference channel in a wireless communication system.
BACKGROUND
[0002] To meet the demand for wireless data traffic having increased since deployment of 4th generation (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post Long Term Evolution (LTE) System’.
[0003] The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
[0004] In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
[0005] In the 5G system, Hybrid frequency shift keying (FSK) and quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
[0006] Communication systems have assumed an interference signal as a Gaussian distribution to operate (adaptive modulation and encoding operation, soft-decision decoding metric generation, etc.) the system with low complexity. Owing to this, the communication systems have mainly used a Quadrature Amplitude Modulation (QAM)—series modulation scheme in order to make a characteristic of the interference signal maximally close to a Gaussian model. Also, the communication systems used a scheme of achieving target error performance by repeatedly transmitting QAM symbols to terminals that are not able to satisfy the target error performance even if applying a minimum channel code rate and a minimum modulation order.
[0007] However, in a recent wireless communication network, it was proved that a case where a statistical distribution of an additive noise follows a Gaussian distribution is the worst case in view of a channel capacity. Accordingly, it is obvious that, if a statistical distribution of interference signals having a characteristic of the additive noise follows a non-Gaussian distribution, it may get a higher network throughput than a conventional system.
[0008] A modulation scheme proposed for this reason is Frequency and Quadrature—Amplitude Modulation (FQAM). The FQAM is a hybrid modulation scheme in which QAM and Frequency-Shift Keying (FSK) are combined and only some of many subcarriers configuring a symbol are activated and therefore, a statistical distribution of an interference signal has a non-Gaussian characteristic.
[0009] This has similarities with a conventional FSK modulation scheme, but the FQAM transmits a QAM symbol to an activated subcarrier, thereby being capable of greatly improving a spectral efficiency than the FSK scheme.
[0010] If the FQAM is applied to users of a cell boundary where an interference signal is very strong, a non-Gaussian interference channel may be formed. Also, the FQAM repeatedly transmits the QAM symbol, thereby being capable of very greatly improving a network throughput compared to a system that forms a Gaussian interference channel To apply the modulation scheme such as the FQAM and achieve performance improvement, it is essential to apply a non-binary encoding/decoding technology. However, the non-binary encoding/decoding technology has a problem in which complexity is very large.
DETAILED DESCRIPTION OF THE INVENTION
Technological Problem
[0011] An object of the present invention is to provide a modulation method and apparatus for generating a non-Gaussian interference channel in a wireless communication system.
[0012] Another object of the present invention is to provide a modulation method and apparatus for generating a non-Gaussian interference channel that is low in complexity and provides an excellent channel capacity in a wireless communication system.
[0013] A further object of the present invention is to provide a method and apparatus for forming a non-Gaussian interference channel and improving a network throughput in a wireless communication system.
[0014] A still another object of the present invention is to provide a method and apparatus for reducing the complexity of a non-binary encoding/decoding technology using a nulling scheme in a wireless communication system.
Means for Solving Problem
[0015] According to a first aspect of the present invention, in an operation method of a base station in a wireless communication system, the method is including receiving, from a terminal, at least one piece of information among channel quality information on a resource region allocated to the terminal and non-Gaussian information on a nulling region that corresponds to the resource region, and determining a modulation order for the terminal, a code rate and a ratio of the resource region to the nulling region based on the channel quality information and the non-Gaussian information.
[0016] According to a second aspect of the present invention, in an operation method of a terminal in a wireless communication system, the method is including determining channel quality information on an allocated resource region, measuring non-Gaussian information on a nulling region that corresponds to the resource region, and transmitting, to a base station, the channel quality information and the non-Gaussian information.
[0017] According to a third aspect of the present invention, in an apparatus of a base station in a wireless communication system, the apparatus is including a modem receiving, from a terminal, channel quality information on a resource region allocated to the terminal and non-Gaussian information on a nulling region that corresponds to the resource region, and a control unit determining a modulation order for the terminal, a code rate and a ratio of the resource region to the nulling region based on the channel quality information and the non-Gaussian information.
[0018] According to a fourth aspect of the present invention, in an apparatus of a terminal in a wireless communication system, the apparatus is including a control unit determining channel quality information on an allocated resource region and non-Gaussian information on a nulling region that corresponds to the resource region, and a modem transmitting, to a base station, the channel quality information and the non-Gaussian information.
Effects of the Invention
[0019] The present invention has an advantage of being capable of forming a non-Gaussian interference channel, and greatly improving performance compared to an existing Quadrature Amplitude Modulation (QAM) scheme using binary channel codes.
[0020] The present invention has an advantage of applying to a communication system that cannot apply Frequency and Quadrature—Amplitude Modulation (FQAM) due to the complexity of non-binary channel codes, thereby being capable of forming a non-Gaussian interference channel and due to this, being capable of improving performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a first diagram illustrating a Nulling Quadrature Amplitude Modulation (NQAM) scheme according to an exemplary embodiment of the present invention.
[0022] FIG. 2 is a second diagram illustrating an NQAM scheme according to an exemplary embodiment of the present invention.
[0023] FIG. 3 is a diagram illustrating an operation scheme using NQAM according to an exemplary embodiment of the present invention.
[0024] FIG. 4 is a flowchart illustrating a process for determining modulation and coding scheme (MCS) level in a base station according to an exemplary embodiment of the present invention.
[0025] FIG. 5 is a flowchart illustrating a detailed process for determining MCS level in a base station according to an exemplary embodiment of the present invention.
[0026] FIG. 6 is a block diagram illustrating a transmission device according to an exemplary embodiment of the present invention.
[0027] FIG. 7 is a block diagram illustrating a reception device according to an exemplary embodiment of the present invention.
[0028] FIG. 8 is a flowchart illustrating an operation process of a transmission device according to an exemplary embodiment of the present invention.
[0029] FIG. 9 is a flowchart illustrating an operation process of a reception device according to an exemplary embodiment of the present invention.
[0030] FIG. 10 is a block diagram illustrating a construction of an electronic device according to an exemplary embodiment of the present invention.
[0031] FIG. 11 is a diagram illustrating an interference channel distribution according to an exemplary embodiment of the present invention.
[0032] FIG. 12 is a first diagram illustrating performance according to an exemplary embodiment of the present invention.
[0033] FIG. 13 is a second diagram illustrating performance according to an exemplary embodiment of the present invention.
BEST MODE FOR EMBODIMENT OF THE INVENTION
[0034] A preferred exemplary embodiment of the present invention is described below in detail with reference to the accompanying drawings. And, in describing the present invention, if it is determined that a concrete description of related known functions or constructions may unnecessarily obscure the gist of the present invention, a detailed description thereof is omitted. And, the terms described later, terms defined considering functions in the present invention, may be modified in accordance to terminal, operator's intention or practice, etc. Therefore, the definition should be given based on the content throughout the present specification.
[0035] Below, the present invention will describe a modulation method and apparatus for generating a non-Gaussian interference channel in a wireless communication system.
[0036] By non-Gaussianizing an interference channel, the present invention increases a network throughput. The present invention proposes a modulation method of forming a non-Gaussian interference channel, instead of a conventional technology (Quadrature Amplitude Modulation (QAM)+repetition) of forming a Gaussian interference channel Particularly, the present invention increases a power of a QAM symbol and adds at least one unused subcarrier, instead of QAM+repetition. In this case, the present invention applies a pattern of inactivating a subcarrier such that it seems like randomly inactivating the subcarrier in a different user viewpoint.
[0037] And, a transmission power of an used resource increases according to a ratio of a resource inactivated. And, the present invention performs permutation of the unit of subcarrier within a Resource Block (RB) allocated every Orthogonal Frequency Division Multiple Access (OFDMA) symbol. In this case, the present invention applies a different permutation rule every each cell.
[0038] The present invention decreases complexity by applying of binary channel codes. A conventional Frequency-Quadrature Amplitude Modulation FQAM scheme forms a non-Gaussian interference channel but is not available for performance improvement compared to QAM+repetition until applying non-binary channel codes of the same order as a modulation order having a very large complexity compared to the binary channel codes.
[0039] However, the present invention is available for performance improvement even by applying of binary codes compared to QAM+repetition. That is, the present invention forms a non-Gaussian interference channel similarly with the FQAM scheme but may greatly decrease the complexity by applying the binary codes.
[0040] FIG. 1 is a first diagram illustrating a Nulling QAM (NQAM) scheme according to an exemplary embodiment of the present invention.
[0041] Referring to the FIG. 1 , the present invention proposes a modulation method of forming a non-Gaussian interference channel in place of a technology (QAM+repetition) of forming a Gaussian interference channel Particularly, the present invention uses a scheme of increasing a power of a QAM symbol and inactivating at least one unused subcarrier, instead of QAM+repetition.
[0042] In this case, by performing an interleaving process, the present invention applies a pattern of inactivating a subcarrier such that it seems like randomly inactivating the subcarrier in a different user viewpoint. And, the present invention increases a transmission power of an used resource, suitable to a ratio of a resource inactivated.
[0043] And, the present invention performs permutation of the unit of subcarrier within a resource block allocated every OFDMA symbol. In this case, a different permutation rule is applied every each cell. A permutation rule every available cell is given as below.
[0044] First, the present invention may perform permutation of the unit of subcarrier within the allocated whole resource region. Or, the present invention may perform grouping by subcarriers of an integer number within the allocated whole resource region and perform permutation of the unit of corresponding group. Or, the present invention may perform permutation of the unit of subcarrier for each OFDMA symbol within the allocated whole resource region. In this case, the present invention may apply the same permutation rule every OFDMA symbol, or apply permutation rules different from one another every OFDMA symbol. Or, the present invention may perform grouping by subcarriers of an integer number for each OFDMA symbol within the allocated whole resource region and perform permutation of the unit of corresponding group. In this case, the present invention may apply the same permutation rule every OFDMA symbol, or apply permutation rules different from one another every OFDMA symbol.
[0045] FIG. 2 is a second diagram illustrating an NQAM scheme according to an exemplary embodiment of the present invention.
[0046] Referring to the FIG. 2 , the present invention proposes a modulation method of forming a non-Gaussian interference channel in place of a technology (QAM+repetition) forming a Gaussian interference channel as mentioned above.
[0047] For this, the present invention separately operates a band using existing QAM and a band (or nulling subcarrier region) using NQAM in order to form the non-Gaussian interference channel using the NQAM.
[0048] The figure represents that, in a corresponding slot, bands of RB-(N+1) to RB-M are bands using NQAM, and bands of RB-1 to RB-N are bands using QAM.
[0049] FIG. 3 is a diagram illustrating an operation scheme using NQAM according to an exemplary embodiment of the present invention.
[0050] Referring to the FIG. 3 , a base station 310 requests a channel state report to a terminal 350 (step a). In this case, a channel state that is requested to the terminal 350 to report includes a Signal-to-Interference-Plus-Noise Ratio (SINR) of a resource region that the terminal 350 is allocated, and/or the non-Gaussianity of an NQAM region.
[0051] Thereafter, the terminal 350 measures the channel state of the allocated resource region and reports the channel state to the base station 310 (step b). In this case, the channel state that the terminal 350 reports includes the SINR of the resource region that the terminal 350 is allocated, and/or the non-Gaussianity of the NQAM region (or nulling subcarrier region).
[0052] Thereafter, the base station 310 determines a modulation and coding scheme (MCS) level suitable to the terminal 350 using the SINR and the non-Gaussianity of the NQAM region which are provided from the terminal 350 (step c).
[0053] Thereafter, the base station 310 transmits, to the terminal 350 , a signal according to the determined MCS level (step d). Thereafter, the base station 310 notifies the terminal 350 of the determined MCS level (step e). Here, the step d) and step e) may be carried out concurrently.
[0054] Thereafter, the terminal 350 applies the received MCS level to a reception signal demodulation process (step f).
[0055] FIG. 4 is a flowchart illustrating a process for determining MCS level in a base station according to an exemplary embodiment of the present invention.
[0056] Referring to the FIG. 4 , if an SINR that is reported from a terminal is greater than S th (step 410 ), a base station determines an MCS level like a conventional system that uses QAM. That is, it determines a predefined MCS level (a code rate and/or a QAM modulation order) in accordance with the SINR as in the existing (step 420 ). Here, the S th is a threshold value determining whether to used NQAM or not.
[0057] If the SINR that the terminal reports is not greater than the S th (step 410 ), it determines an MCS level of the terminal, in consideration of the non-Gaussianity (a) of an NQAM region that is reported from the terminal (step 430 ). Here, the base station determines the number of allocation subcarriers/the number of nulling subcarriers, a code rate, and/or a modulation order of QAM.
[0058] A process of getting the α that is the non-Gaussianity in the present invention is given as follows.
[0059] Most of channel decoders receive a Log-Likelihood Ratio (LLR) as an input and estimate an information bit or symbol. Generally, a binary decoder determines the LLR as in <Equation 1> below.
[0000]
L
k
,
λ
BICM
(
H
^
[
k
]
,
y
[
k
]
)
=
ln
∑
w
∈
A
0
λ
f
Y
[
k
]
(
y
[
k
]
H
^
[
k
]
,
s
[
k
]
=
w
)
∑
w
∈
A
1
λ
f
Y
[
k
]
(
y
[
k
]
H
^
[
k
]
,
s
[
k
]
=
w
)
Equation
1
[0060] In the <Equation 1>, the L k,λ BICM represents an LLR of a λth bit of a kth symbol corresponding to binary decoding, the Ĥ[k] represents the estimation of a channel coefficient for a kth transmission symbol, the y[k] represents a reception signal corresponding to the kth transmission symbol, the A 0 λ represents a set of candidate symbols whose λth bits are equal to 0, the A 1 λ represents a set of candidate symbols whose λth bits are equal to 1, the f Y[k] represents a PDF for a kth reception symbol, and the s[k] represents the kth transmission symbol. The w is a dummy variable representing a symbol candidate that is available for transmission. In a case of 16-QAM, the A 0 λ includes 8 symbols among the whole 16 symbols, and the A 1 λ includes the remnant 8 symbols.
[0061] As one may know through the <Equation 1>, determination of a Probability Density Function (PDF) is needed.
[0062] As a representative method among existing non-Gaussian decoding methods, there is a Complex Generalized Gaussian (CGG) decoding scheme. The CGG decoding scheme assumes that an interference signal or a noise follows a CGG distribution, and determines an LLR or PDF and provides the determination result as an input of a channel decoder. Because the CGG decoding scheme includes a Gaussian decoding scheme, the present invention explains only the CGG decoding scheme. A PDF of the CGG distribution is given as in <Equation 2> below.
[0000]
f
z
^
(
z
α
,
β
)
=
α
2
πβ
2
Γ
(
2
α
)
exp
(
-
(
z
β
)
α
)
Equation
2
[0063] In the <Equation 2>, the f {circumflex over (z)} is defined as a PDF of a noise, the Z is a variable representing a noise, the α is a shape parameter and is a variable expressing the non-Gaussianity, the β is a scale parameter and is a variable expressing a variance, and the Γ is a gamma function and is defined as Γ(z){circumflex over (=)}∫ 0 ∞ t z-1 exp(−t)dt.
[0064] In the <Equation 2>, the PDF of the CGG distribution follows a Gaussian distribution if the α is equal to 2, and follows a super Gaussian distribution having a heavy-tail if the α is less than 2, and follows a sub Gaussian distribution having a light-tail if the α is greater than 2 That is, if the α is equal to 2, the CGG decoding scheme is identical with the Gaussian decoding scheme.
[0065] Most of interference signals and noises are modeled into super Gaussian or Gaussian in which the α belongs to a range of 0 to 2. The β called the scale parameter performs a role such as a variance of the Gaussian PDF. PDFs used for most of non-Gaussian decoding schemes include the shape parameter and scale parameter such as the α and β of the CGG distribution. Accordingly, the present invention explains the CGG as an example, but it is obvious that the present invention is identically applicable even to most of the existing non-Gaussian decoding schemes.
[0066] In order to CGG-decode QAM, determination of a PDF equation such as <Equation 3> below is required.
[0000]
f
Y
[
k
]
(
y
[
k
]
H
^
[
k
]
,
s
[
k
]
)
=
α
2
πβ
2
Γ
(
2
/
a
)
exp
(
-
(
y
[
k
]
-
H
^
[
k
]
s
[
k
]
β
)
α
)
Equation
3
[0067] In the <Equation 3>, the f Y[k] ( ) is defined as a PDF of a transmission symbol, the y[k] represents a reception signal corresponding to a kth transmission symbol, the Ĥ[k] represents a channel coefficient for the kth transmission symbol, the s[k] represents the kth transmission symbol, the α represents a shape parameter, the β represents a scale parameter, and the F is a gamma function and is defined as Γ(z){circumflex over (=)}t z-1 exp(−t)dt.
[0068] A method of estimating the α value and the β value of the <Equation 3> exists variously. Below, the present invention explains a moment matching technique that is a previously proposed method, for example. According to the moment matching technique, the α value and the β value are estimated by matching a primary moment and a secondary moment. If expressing the estimation of the α value and the β value by an equation, it is given as in <Equation 4> below.
[0000]
α
=
ln
(
3
6
/
2
10
)
ln
(
(
E
[
J
^
[
k
]
]
)
2
/
E
[
J
^
[
k
]
2
]
-
π
4
+
9
2
3.5
)
+
ln
(
3
2
2
)
J
^
[
k
]
=
y
[
k
]
-
H
^
[
k
]
s
^
[
k
]
β
=
Γ
(
2
/
α
)
Γ
(
3
/
α
)
E
[
J
^
[
k
]
]
Equation
4
[0069] In the <Equation 4>, the α is defined as a shape parameter, the β represents a scale parameter, the y[k] represents a reception signal corresponding to a kth transmission symbol, the Ĥ[k] represents a channel coefficient for the kth transmission symbol, the ŝ[k] represents the kth transmission symbol estimated in a hard decision scheme, and the Γ is a gamma function and is defined as Γ(z){circumflex over (=)}∫ 0 ∞ t z-1 exp(−t)dt.
[0070] FIG. 5 is a flowchart illustrating a detailed process for determining MCS level in a base station according to an exemplary embodiment of the present invention.
[0071] Referring to the FIG. 5 , if an SINR that a terminal reports is greater than S th (step 505 ), a base station determines an MCS level according to an existing scheme, without using NQAM (step 510 ). Here, the S th is a threshold value determining whether to use NQAM or not.
[0072] If the SINR that the terminal reports is a value near the S th , and α is a value close to 2 (step 515 ), that is, a channel has a strong Gaussian characteristic, the base station decreases R n to enhance a non-Gaussian characteristic of a wireless channel (step 520 ) and determines R c and M using a variation of the α according to R n and the SINR value and determines an MCS level according to R c and M (step 525 ). Here, the R n , is a ratio of an allocation subcarrier to a nulling subcarrier. That is, the R n =allocation subcarrier/nulling subcarrier. And, the non-Gaussian characteristic is shown strong as the nulling subcarrier increases or the R n , decreases.
[0073] The R c is a code rate of a wireless channel, and the M represents a QAM modulation order. The base station may determine the R c , M, and R n , and determine the MCS level according to R c , M, and R n .
[0074] If the SINR that the terminal reports is a value near the S th , and the α is much less than 2 (step 530 ), that is, a channel has a strong non-Gaussian characteristic (step 530 ), the base station determines R n , suitable to the non-Gaussian characteristic α of a current wireless channel and determines R c and M using the α and SINR value and determines an MCS level according to R c and M (step 535 ).
[0075] If the SINR that the terminal reports is a value much less than the S th , and the α is a value close to 2 (step 540 ), that is, a channel has a strong Gaussian characteristic, the base station sets R n , to have a very small value to enchance the non-Gaussian characteristic of a wireless channel (step 545 ), and determines R c , M using a variation of the α according to R n and the SINR value and sets an MCS level according to R c and M (step 550 ).
[0076] If the SINR that the terminal reports is a value much less than the S th , and the α is a value much less than 2 (step 555 ), that is, a channel has a strong non-Gaussian characteristic, the base station determines R n suitable to the non-Gaussian characteristic α of a current wireless channel and determines R c and M using the α and the SINR value and determines an MCS level according to R c and M (step 560 ).
[0077] In the FIG. 5 , it may be appreciated that the R c , M, R n decrease as the α of an NQAM band increases, that is, as the non-Gaussian characteristic of a wireless channel decreases, and the R c , M, R n increase as the α of the NQAM band decreases, that is, as the non-Gaussian characteristic of the wireless channel increases.
[0078] FIG. 6 is a block diagram illustrating a transmission device according to an exemplary embodiment of the present invention.
[0079] Referring to the FIG. 6 , it illustrates a block construction of the transmission device, and an information bit is inputted to and binary channel encoding is performed in an encoding unit 605 . The binary channel encoded information bit is interleaved in an interleaving unit 610 , and the interleaved information bit is modulated in a modulation unit 615 . The modulation unit 615 can, for example, use QAM as a modulation scheme.
[0080] Thereafter, a modulated QAM symbol is inputted to a nulling subcarrier determining unit 620 , and the nulling subcarrier determining unit 620 determines and sets a nulling subcarrier when determining a subcarrier to map in the modulated QAM symbol. That is, the nulling subcarrier determining unit 620 determines and sets and maps the nulling subcarrier in the modulated QAM symbol in accordance with R n that is a ratio of an allocation subcarrier to a nulling subcarrier. The outputted subcarrier is inputted to a subcarrier permutation unit 625 .
[0081] Thereafter, the subcarrier permutation unit 625 performs permutation by the unit of subcarrier and outputs the permutation result. The output of the subcarrier permutation unit 625 is inputted to an OFDMA signal processing unit 630 . The OFDMA signal processing unit 630 constructs OFDMA symbols through Inverse Fast Fourier Transform (IFFT) operation and Cyclic Prefix (CP) insertion. The present invention describes based on an OFDMA system, but is possible to expand to an Orthogonal Frequency Division Multiplexing (OFDM) system as well.
[0082] FIG. 7 is a block diagram illustrating a receiver according to an exemplary embodiment of the present invention.
[0083] Referring to the FIG. 7 , it illustrates a block construction of the receiver, and a reception signal is inputted to and processed in an OFDMA signal processing unit 705 . The OFDMA signal processing unit 705 divides the reception signal by the unit of OFDMA symbol, and restores signals mapped to subcarriers through Fast Fourier Transform (FFT) operation and outputs.
[0084] Thereafter, a subcarrier depermutation unit 710 performs depermutation of the unit of subcarrier for an output signal of the OFDMA signal processing unit 705 .
[0085] Thereafter, non-Gaussianity is determined in a non-Gaussian determining unit 715 . That is, the non-Gaussianity determining unit 715 determines the non-Gaussianity (α) of a wireless channel that uses a nulling subcarrier. Also, the non-Gaussian determining unit 715 provides an output signal of the OFDMA signal processing unit 705 to a demodulation unit 720 .
[0086] Thereafter, the demodulation unit 720 demodulates a provided signal in accordance with an MCS level presented by a base station.
[0087] Thereafter, the deinterleaving unit 725 deinterleaves the demodulated signal, and the decoding unit 730 decodes the deinterleaved signal in accordance with a code rate (R c ) presented by the base station and outputs a demodulation bit. The present invention describes based on an OFDMA system, but is possible to expand to an OFDM system as well.
[0088] FIG. 8 is a flowchart illustrating an operation process of a transmission device according to an exemplary embodiment of the present invention.
[0089] Referring to the FIG. 8 , an information bit is inputted to and binary channel encoding is performed in the encoding unit 605 (step 805 ). The binary channel encoded information bit is interleaved in the interleaving unit 610 (step 810 ), and the interleaved information bit is modulated in the modulation unit 615 (step 815 ). Here, the modulation unit 615 may use QAM as a modulation scheme. Thereafter, a modulated QAM symbol is inputted to the subcarrier determining unit 620 , and the subcarrier determining unit 620 determines and sets a nulling subcarrier when determining a subcarrier to map in the modulated QAM symbol (step 820 ). That is, the subcarrier determining unit 620 determines and sets and maps the nulling subcarrier in the modulated QAM symbol in accordance with R n that is a ratio of an allocation subcarrier to a nulling subcarrier. The outputted subcarrier is inputted to the subcarrier permutation unit 625 .
[0090] Thereafter, the subcarrier permutation unit 625 performs permutation by the unit of subcarrier and outputs the permutation result (step 825 ). The output of the subcarrier permutation unit 625 is inputted to the OFDMA signal processing unit 630 . The OFDMA signal processing unit 630 constructs OFDMA symbols through Inverse Fast Fourier Transform (IFFT) operation and Cyclic Prefix (CP) insertion (step 830 ). The present invention describes based on an OFDMA system, but is possible to expand to an OFDM system as well.
[0091] FIG. 9 is a flowchart illustrating an operation process of a reception device according to an exemplary embodiment of the present invention.
[0092] Referring to the FIG. 9 , a reception signal is inputted to and processed in the OFDMA signal processing unit 705 (step 905 ). The OFDMA signal processing unit 705 divides the reception signal by the unit of OFDMA symbol, and restores signals mapped to subcarriers through Fast Fourier Transform (FFT) operation and outputs the signals.
[0093] Thereafter, the subcarrier depermutation unit 710 performs depermutation of the unit of subcarrier for an output signal of the OFDMA signal processing unit 705 (step 910 ).
[0094] Thereafter, non-Gaussianity is determined in the non-Gaussian determining unit 715 (step 915 ). That is, the non-Gaussianity determining unit 715 determines the non-Gaussianity (α) of a wireless channel that uses a nulling subcarrier. Also, the non-Gaussian determining unit 715 provides an output signal of the OFDMA signal processing unit 705 to the demodulation unit 720 . The non-Gaussianity (α) may be reported to a base station.
[0095] Thereafter, the demodulation unit 720 demodulates a provided signal in accordance with an MCS level presented by the base station (step 920 ). For one example, QAM demodulation may be used.
[0096] Thereafter, the deinterleaving unit 725 deinterleaves the demodulated signal (step 925 ), and the decoding unit 730 decodes the deinterleaved signal in accordance with a code rate (R c ) presented by the base station and outputs a demodulation bit (step 930 ).
[0097] The present invention describes based on an OFDMA system, but is possible to expand to an OFDM system as well.
[0098] FIG. 10 is a block diagram illustrating a construction of an electronic device according to an exemplary embodiment of the present invention.
[0099] Referring to the FIG. 10 , the electronic device corresponds to a base station or a terminal in the present invention. The electronic device includes a memory 1010 , a processor unit 1020 , an input output control unit 1040 , a display unit 1050 and an input device 1060 . Here, the memory 1010 may exist in plural. If describing each constituent element, it is given as follows.
[0100] The memory 1010 includes a program storage unit 1011 storing a program for controlling an operation of the electronic device and a data storage unit 1012 storing data generated during program execution.
[0101] The data storage unit 1012 may store data required for operations of an application program 1013 , and an NQAM management unit 1014 .
[0102] The program storage unit 1011 includes the application program 1013 , and the NQAM management unit 1014 . Here, the program included in the program storage unit 1011 , a set of instructions, may be expressed as an instruction set as well.
[0103] The application program 1013 includes an application program that operates in the electronic device. That is, the application program 1013 includes an instruction of an application that is driven by the processor 1022 .
[0104] The electronic device includes a communication processing unit 1090 performing a communication function for voice communication and data communication, and the communication processing unit 1090 may include the transmission unit and the receiver of FIGS. 6 and 7 aforementioned.
[0105] The NQAM management unit 1014 controls an operation of the communication processing unit 1090 such that the base station of the present invention performs the following operations. That is, the NQAM management unit 1014 controls to instruct to control the operation of the communication processing unit 1090 and perform operations as follows.
[0106] The NQAM management unit 1014 controls such that an information bit is inputted to and binary channel encoding is performed in the encoding unit 605 .
[0107] The NQAM management unit 1014 controls such that the binary channel encoded information bit is interleaved in the interleaving unit 610 .
[0108] The NQAM management unit 1014 controls such that the interleaved information bit is modulated in the modulation unit 615 . Here, the NQAM management unit 1014 may use QAM as a modulation scheme.
[0109] The NQAM management unit 1014 controls such that the subcarrier determining unit 620 determines and sets a nulling subcarrier when determining a subcarrier to map in a modulated QAM symbol. That is, the NQAM management unit 1014 controls to determine and set and map the nulling subcarrier in the modulated QAM symbol in accordance with R n that is a ratio of an allocation subcarrier to a nulling subcarrier.
[0110] The NQAM management unit 1014 controls such that the subcarrier permutation unit 625 performs permutation by the unit of subcarrier and outputs the permutation result.
[0111] The NQAM management unit 1014 controls the OFDMA signal processing unit 630 to construct OFDMA symbols through Inverse Fast Fourier Transform (IFFT) operation and Cyclic Prefix (CP) insertion.
[0112] The NQAM management unit 1014 controls an operation of the communication processing unit 1090 to perform the following operations in a terminal of the present invention.
[0113] That is, the NQAM management unit 1014 instructs to control an operation of the communication processing unit 1090 and perform operations as follows.
[0114] The NQAM management unit 1014 controls such that a reception signal is inputted to and processed in the OFDMA signal processing unit 705 . That is, the NQAM management unit 1014 controls the OFDMA signal processing unit 705 to divide the reception signal by the unit of OFDMA symbol, and restore signals mapped to subcarriers through Fast Fourier Transform (FFT) operation and output the signals.
[0115] The NQAM management unit 1014 controls the subcarrier depermutation unit 710 to perform depermutation of the unit of subcarrier for an output signal of the OFDMA signal processing unit 705 .
[0116] The NQAM management unit 1014 controls the non-Gaussian determining unit 715 to determine non-Gaussianity. That is, the NQAM management unit 1014 controls the non-Gaussianity determining unit 715 to determine the non-Gaussianity (α) of a wireless channel that uses a nulling subcarrier.
[0117] The NQAM management unit 1014 controls the demodulation unit 720 to demodulate a provided signal in accordance with an MCS level presented by a base station. For one example, QAM demodulation may be used.
[0118] The NQAM management unit 1014 controls the deinterleaving unit 725 to deinterleave the demodulated signal.
[0119] The NQAM management unit 1014 controls the decoding unit 730 to decode the deinterleaved signal in accordance with a code rate (R c ) presented by a base station and output a demodulation bit.
[0120] The present invention describes based on an OFDMA system, but is possible to expand to an OFDM system as well.
[0121] The memory interface 1021 controls access to the memory 1010 by a constituent element such as the processor 1022 or the peripheral interface 1023 .
[0122] The peripheral interface 1023 controls the connection of the processor 1022 and the memory interface 1021 with an input output peripheral device of the base station.
[0123] The processor 1022 controls the base station to provide a corresponding service using at least one software program. At this time, the processor 1022 executes at least one program stored in the memory 1010 and provides a service corresponding to the corresponding program.
[0124] The input output control unit 1040 provides an interface between an input output device such as the display unit 1050 and the input device 1060 , etc. and the peripheral interface 1023 .
[0125] The display unit 1050 displays state information, an inputted character, a moving picture and a still picture, etc. For example, the display unit 1050 displays application program information that is driven by the processor 1022 .
[0126] The input device 1060 provides input data generated by selection of the electronic device to the processor unit 1020 through the input output control unit 1040 . At this time, the input device 1060 includes a key pad including at least one hardware button and a touch pad sensing touch information, etc. For example, the input device 1060 provides touch information of a touch sensed through the touch pad, a touch and drag, a touch and release, etc. to the processor 1022 through the input output control unit 1040 .
[0127] In various exemplary embodiments, an apparatus of a terminal in a wireless communication system may include a control unit determining channel quality information on an allocated resource region and non-Gaussian information on a nulling region corresponding to the resource region, and a modem transmitting the channel quality information and the non-Gaussian information to a base station.
[0128] In various exemplary embodiments, the modem may receive a signal for a modulation order and code rate on which the non-Gaussian information is reflected, and receive information on the allocated region.
[0129] In various exemplary embodiments, the modem may receive information on the allocated region.
[0130] FIG. 11 is a diagram illustrating an interference channel distribution according to an exemplary embodiment of the present invention.
[0131] Referring to the FIG. 11 , FQAM is an environment in which one subcarrier is activated every four subcarriers. Even a scheme of the present invention sets to make vacant three subcarriers per one data subcarrier. It may be checked that NQAM of the present invention may form a non-Gaussian interference channel similar with that of the FQAM.
[0132] FIG. 12 is a first diagram illustrating performance according to an exemplary embodiment of the present invention.
[0133] Referring to the FIG. 12 , in a 3-cell structure, it may be appreciated that, at applying of a scheme of the present invention, a network throughput is double increased compared to the existing QAM+repetition.
[0134] It may be appreciated that the scheme of the present invention provides a great performance improvement effect compared to the existing scheme in a situation in which a channel estimation error takes place. This is because a pilot damage is decreased by a subcarrier made vacant in the present invention.
[0135] FIG. 13 is a second diagram illustrating performance according to an exemplary embodiment of the present invention.
[0136] Referring to the FIG. 13 , in a 7-cell structure, it may be appreciated that, at applying of a scheme of the present invention, a network throughput is increased by one and a half times compared to the existing QAM+repetition. It may be appreciated that, if an interference cell is is increased, a performance improvement effect is decreased, but the performance of the proposed method is still superior to that of the existing scheme.
[0137] While a concrete exemplary embodiment has been described in a detailed description of the present invention, it is undoubted that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited and defined by the described exemplary embodiment and should be defined by not only the scope of claims described later but also equivalents to this scope of the claims.
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The present disclosure relates to a pre-5 th -Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). Provided is an operation method of a base station in a wireless communication system. The method comprises: receiving, from a terminal, at least one piece of information among channel quality information on a resource region allocated to the terminal and non-Gaussian information on a nulling region corresponding to the resource region; and determining a modulation order for the terminal, a code rate, a ratio of the resource region to the nulling region based on the channel quality information and the non-Gaussian information.
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BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to an apparatus for controlling group supervisory operation of elevators which is capable of centrally controlling a plurality of elevator cars in order to make them run efficiently and, in particular, to a highly reliable apparatus for controlling group supervisory operation of elevators which is capable of preventing a considerable decrease in group control functions when an elevator develops a fault.
2. Description of the Related Art
FIG. 4 is a block diagram showing the construction of a conventional apparatus for controlling group supervisory operation of elevators which is, for example, disclosed in Japanese Patent Laid-Open No. 59-124667. In FIG. 4, reference numeral 1 denotes a first computer which has a CPU 1a, a ROM 1b, and a RAM 1c. Likewise, reference numeral 2 denotes a second computer which has a CPU 2a, a ROM 2b, and a RAM 2c. Reference numeral 3 denotes a fault detection logic circuit, connected between these first and second computers 1 and 2, for monitoring the operating status thereof. Reference numerals 4a and 4b each denote a peripheral interface adapter (PIA) employed as a programmable general-purpose input/output interface element. These adapters 4a and 4b are respectively connected to the first computer 1 and the second computer 2 and controlled by the CPUs 1a and 2a, respectively. Reference numerals 5a, 5b. . . 5h each denote a car control apparatus for controlling the running status of each of a plurality of elevator cars (not shown). Reference numeral 6a denotes an input/output bus connected to a PIA 4a or 4b via a switch 7a and connected to a hall call registration button HB. Reference numeral 6b denotes an input/output bus connected to a PIA 4a or 4b via a switch 7b and connected to a hall call registration lamp HL. Reference numeral 6c denotes an input/output bus connected to a PIA 4a or 4b via a switch 7c and connected to each of the car control apparatus 5a, 5b. . . 5h. Reference numeral 6 d denotes an input/output bus connected to a PIA 4a or 4b via a switch 7d and connected to each of the car control apparatuses 5a, 5b. . . 5h. These input/output buses 6a to 6d are controlled by the PIAs 4a and 4b. Switches 7a to 7d form an input/output bus automatic switching apparatus 7 which operates in response to the detection output from the fault detection logic circuit 3.
The switches 7a to 7d are kept in a state shown in FIG. 4 when no fault of either the first computer 1 or the second computer 2 is detected by the fault detection logic circuit 3. That is, input/output buses 6a, 6b, and 6c are each connected to the PIA 4a and placed under the control of the first computer 1 and the input/output bus 6d is connected to the PIA 4b and placed under the control of the second computer 2. However, if the second computer 2 should develop a fault in a state in which the first computer 1 is operating normally, because the switch 7d is switched by the detection output from the fault detection logic circuit 3, the input/output bus 6d for communicating with car control apparatuses 5a, 5b. . . 5h is connected to the CPU 1a via the PIA 4a, placed under the control of the first computer 1, and disconnected from the faulty second computer 2. In contrast, if the first computer 1 should develop a fault in a state in which the second computer 2 is operating normally, because the switches 7a, 7b, and 7c are switched by the detection output from the fault detection logic circuit 3, the input/output buses 6a to 6d are connected to the second computer 2, placed under the control of the second computer 2 and disconnected from the faulty first computer 1.
In such a conventional apparatus for controlling group supervisory operation of elevators as described above, the construction of hardware for switching the input/output of the input/output buses is extremely complex, and the reliability of the input/output path through which signals are input and output decreases. Also, as the group control functions have improved in recent years, the amount of control information handled by the first and second computers 1 and 2 has increased and the amount of data transmitted between the two CPUs 1a and 2a has also increased. Therefore, such an arrangement of separate buses is problematical in that it is not possible to transmit a large amounts of data with high efficiency.
SUMMARY OF THE INVENTION
The present invention has been devised to solve the above-mentioned problems. Accordingly, an object of the present invention is to obtain a highly reliable apparatus for controlling group supervisory operation of elevators, in which a duplex system using two computers is realized and the transmission of large amounts of data between the two CPUs is performed efficiently, thus improving the group control function, and in which, if one of the computers should develop a fault, a considerable decrease in the group control functions will not occur.
To this end, according to the present invention, there is provided an apparatus for controlling group supervisory operation of elevators comprising: a first computer for performing hall call control and car assignment control at usual times; a second computer for performing learning control at usual times; a system bus which connects the first computer to the second computer; and an abnormality detection means for disconnecting a computer which has developed a fault from the system bus if an abnormality of either the first computer or the second computer is detected and for making the computer which is operating normally perform the functions of the two computers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an apparatus for controlling group supervisory operation of elevators of an embodiment of the present invention;
FIG. 2 is a flowchart showing the operation of a first computer of the embodiment of the present invention;
FIG. 3 is a flowchart showing the operation of a second computer of the embodiment of the present invention;
FIG. 4 is a block diagram showing a conventional apparatus for controlling group supervisory operation of elevators.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the present invention will be explained hereinbelow with reference to the accompanying drawings.
In FIG. 1, a first computer 10 and a second computer 20 are connected to a system bus 50, the various functions being divided individually therebetween. These first and second computers 10 and 20 have CPUs 1a and 2a, ROMs 1b and 2b, RAMs 1c and 2c, input/output interface circuits 1d and 2d which interface with various kinds of external devices (not shown), gates 1e and 2e which connect the system bus 50 to each of the respective buses in the computers, and bus arbitration circuits 1f and 2f for controlling the exclusive use of the system bus 50 when each respective computer uses the system bus 50. The opening/closing of the gates 1e and 2e is controlled by the bus arbitration circuits 1f and 2f, respectively. Reference numeral 30 denotes an abnormality detection circuit, connected to the first computer 10 and the second computer 20 through the system bus 50, for monitoring the operating status of the computers. Reference numeral 40 denotes a memory which is shared by the first computer 10 and the second computer 20 through the system bus 50. Reference numeral 60 denotes a transmission control section for controlling the transmission among car control apparatuses 5a. . . 5h. The transmission control section 60 has a two-port memory 61 by which data is transmitted between the first computer 10 and the second computer 20, as well as a CPU, a ROM, a RAM and an I/F circuit for car control apparatuses. Reference numeral 70 denotes an input/output interface for a hall apparatus (not shown) and others.
Next, a description will be provided of the operation of an apparatus for controlling group supervisory operation of elevators constructed as described above. Usually, the first computer 10 mainly performs hall call control and car assignment control and the second computer 20 mainly performs running status learning control, traffic forecasting, etc. The first computer 10 sends and receives data required for group control, such as operation control information, to and from the second computer 20, or vice versa, through a shared memory 40. The exclusive use of the system bus 50 is efficiently switched by the bus arbitration circuits 1f and 2f respectively disposed in the respective computers. Data from car control apparatuses 5a to 5h, input/output data from floors, etc., is processed by the transmission control section 60 and sent and received to and from the first computer 10 through the two-port memory 61 and the system bus 50.
Operations in a case where the first computer 10 fails will now be explained. When the abnormality detection circuit 30 detects that the first computer 10 has failed, an abnormality detection signal 30a is input to the bus arbitration circuit 1f. Thereupon, the bus arbitration circuit 1f outputs a signal to the gate 1e so that the gate 1e is shut off and the first computer 10 is disconnected from the system bus 50. From this time on, the normally operating second computer 20 performs the functions of the first computer 10. In contrast to this, if the second computer 20 is detected to be functioning abnormally, an abnormality detection signal 30b is input to the bus arbitration circuit 2f and the gate 2e is shut off. As a result, the second computer 20 is disconnected from the system bus 50. From this time on, the normally operating first computer 10 performs the functions of the second computer 20.
FIGS. 2 and 3 are flowcharts showing the sequence of the operations of the whole elevator executed by the CPU 1a of the first computer 10 and the CPU 2a of the second computer 20, respectively.
In FIG. 2, when programs of the first computer 10 begin to be executed, first, initialization for respective sections is performed in step 211. A hall call control process is performed in step 212 and a car assignment control process is performed in step 213 in accordance with hall call information or car information obtained via the two-port memory 61 in the transmission control section 60 and control parameters prepared in the second computer 20. It is determined in step 214 whether or not an abnormality of the second computer 20 has been detected by the abnormality detection circuit 30. If it is determined that the second computer 20 is normally functioning without an abnormality being detected, the process returns to step 212 and operations are repeated in a similar manner as described above. If it is determined that the second computer 20 is functioning abnormally, alternative processes for running status learning control and control parameter preparation which should have been performed by the second computer 20 are performed in steps 215 and 216, respectively. Thereafter, the process returns to step 212 and operations are repeated in a similar manner as described above.
Next, in FIG. 3, when programs of the second computer 20 begin to be executed, initialization for respective sections is performed in step 311. It is determined in step 312 whether or not an abnormality of the first computer 10 has been detected by the abnormality detection circuit 30. If it is determined that the first computer 10 is functioning normally, a running status learning control process is performed in step 315 such that characteristics of the traffic peculiar to the building are learned from the past operations of the elevators and traffic in the near future is forecast. Based on the results of the above process, the process of preparing control parameters used for assigning cars by the first computer 10 is performed in step 316. Thereafter, the process returns to step 312, and operations are repeated in a similar manner as described above. If it is detected in step 312 that the first computer 10 has begun functioning abnormally, substitute processes of hall call control and car assignment control which should have been performed by the first computer 10 are performed in steps 313 and 314, respectively. Thereafter, the process returns to step 315 where the process mentioned earlier is performed, and operations are repeated in a similar manner as described above.
Further, in a case where both the first computer 10 and the second computer 20 have failed, this state is detected by the transmission control section 60. Based on this detection, backup running, such as a stop at each of the service floors, and skip running, is performed. Thus, a minimum of functions are maintained.
In the above-mentioned embodiment, the abnormality detection circuit 30 which is commonly used for both the first computer 10 and the second computer 20 is disposed as an abnormality detection means therefor. This abnormality detection circuit may be disposed in each of the computers. The same advantages can be obtained by an arrangement in which an abnormality detection means is formed by software by means of which normal transmission of data is confirmed by the first computer 10 and the second computer 20 by using a shared memory 40 without the abnormality detection circuit 30.
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An apparatus for controlling group supervisory operation of elevators comprises a first computer for performing hall call control and car assignment control at usual times, a second computer for performing learning control at usual times, a system bus which connects the first computer to the second computer, and an abnormality detection device for disconnecting a computer which has developed a fault from the system bus if an abnormality of either the first computer or the second computer is detected and for making the computer which is operating normally perform the functions of the two computers.
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BACKGROUND OF THE INVENTION
This invention relates to a stalling prevention apparatus for preventing an engine from stalling at starting of a vehicle, which is particularly used to good advantage in a vehicle equipped with a manual transmission.
In passenger cars and the like equipped with a small-displacement engine with a manual transmission, with a small output torque at the low-speed range compared to trucks, the engine tends to cause stalling unless the driver carefully sets the degree of pressing down the acceleration pedal and the clutch connection timing at starting of the vehicle.
Such an engine stalling at starting of the vehicle can be prevented by skill of the driver to some extent.
In general, stalling of the engine at the start of the vehicle is caused, in addition to a small output torque of the engine at its low rotation speed range, by a delay in response of the air intake system from pressing of the acceleration pedal until the engine output torque increases. Specifically, since a length of time is required after the acceleration pedal is pressed down to open the throttle valve until a large amount of fuel mixture reaches the engine, if the clutch is actuated simultaneously with pressure of the acceleration pedal, stalling tends to occur due to an insufficient increase in output torque of the engine.
For a vehicle equipped with a manual transmission in which the driver starts the vehicle while adjusting the pressing down of the acceleration pedal and the clutch pedal, some skill is required to start the vehicle. Therefore, a beginner who is not experienced in starting the vehicle tends to cause frequent stalling of the engine.
On the other hand, for a vehicle equipped with an automatic transmission with a torque converter, in which the output torque in the low rotation speed range of the engine is enhanced, generation of stalling at starting of the vehicle is reduced, and even a beginner can easily start the vehicle. However, the use of a torque converter inevitably results in increases in costs of the power transmission system and weight of the vehicle. Especially, it has been a problem to use a torque converter in a small-displacement vehicle which has much limitations in the engine room space and the like.
OBJECT OF THE INVENTION
It is a primary object of the present invention to provide a stalling prevention apparatus which eliminate a delayed response of the air intake system at starting of a vehicle equipped with a manual transmission and can smoothly and rapidly start the vehicle in response to the pressing operation of the acceleration pedal.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a stalling prevention apparatus comprising start preparation detecting means for detecting a start preparation condition of a vehicle, intake air amount increasing means for increasing the amount of intake air when the vehicle is in a start preparation condition compared to an idling condition, rotation speed increase prevention means for suppressing an increase in rotation speed of the engine due to the increase in the amount of intake air by the intake air amount increasing means, start detecting means for detecting a starting condition of the vehicle, and control means for interrupting operations of the intake air amount increasing means and the rotation speed increase prevention means according to a detection signal of the start preparation condition by the start preparation detecting means.
Therefore, when a start preparation condition of the vehicle is detected by the start preparation detecting means, exhaust amount increasing means and the rotation speed increase prevention means are operated by the control means to increase the intake air amount to the engine from that for an idling condition and suppress the resulting increase in engine rotation speed by varying the ignition timing and the fuel supply amount.
When starting of the vehicle is detected by the start detecting means, operation of the intake air amount increasing means and the rotation speed increase prevention means is interrupted by the control means to revert the intake air amount to the engine back to an ordinary control amount according to the pressing amount of the acceleration pedal and the like and also revert the ignition timing and the fuel supply amount back to normal values. As a result, a sufficient amount of intake air is supplied to the engine at starting of the vehicle to eliminate a delay in response of the air intake system to pressing of the acceleration pedal, and the output torque of the engine has already been increased when the clutch is connected, thereby preventing the engine from stalling.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an embodiment in which the stalling prevent apparatus according to the present invention is applied to a vehicle equipped with a 4-cylinder internal combustion engine with an automatic transmission.
FIG. 2 is a control block diagram of the embodiment.
FIG. 3 is a flow chart of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, an air cleaner 16 containing an air cleaner element 15 is connected to the upstream end of an air intake pipe 14 of which the rear end communicates with a combustion chamber 12 of an engine through an air intake valve 13. The air cleaner 16 incorporates an air flow sensor 17 such as a Karman vortex flow meter or the like for detecting the amount of intake air to the combustion chamber of the engine 11. The air flow sensor 17 is connected with an electronic control unit 18 to which is outputted a detection signal from the air flow sensor 17.
The air intake pipe 14 is mounted halfway with a throttle valve 20 for adjusting the amount of intake air supplied to the combustion chamber 12 by varying the opening of an air intake passage 19 formed in the air intake pipe 14 according to the operation of the acceleration pedal (not shown). The throttle valve 20 is mounted with an idle switch 21 for detecting a fully-closed condition of the throttle valve 20. A bypass passage 22, of which both ends communicate with the air intake passage 19 at the upstream and downstream sides of the throttle valve 20, is provided with a needle valve 23 which is capable of controlling the opening of the bypass passage 22. The needle valve 23 is connected with a solenoid 24 which is duty controlled by the electronic control unit 18. Between a bypass pipe 25 forming the bypass passage 22 and the needle valve 23 is disposed a compression coil spring 26 which urges the needle valve 23 to close the bypass passage 22.
When the solenoid 24 is duty driven by the electronic control unit 18 against the force of the compression coil spring 26, open time of the needle valve 23 is controlled independently of the operation the needle valve 23 to suction air into the combustion chamber 12 through the bypass passage 22. The bypass passage 22, the needle valve 23, the solenoid 24, the bypass pipe 25, and the compression coil spring 26 are aimed for idle speed control (ISC) to decrease the rotation speed of the engine 11 and improve the mileage during idling operation of the engine 11, and this embodiment utilizes these components as intake air amount increasing means which will be described later.
This embodiment uses the intake air amount increasing means comprising the bypass passage 22 and the needle valve 23 to open and close the bypass passage 22 by the solenoid 24, however, alternatively, a configuration may be used in which the throttle valve 20 of the engine 11 in the idling operation condition is operated by an actuator.
At the downstream end side of the air intake passage 19 is provided a fuel injection nozzle 27 to inject fuel (not shown) into the combustion chamber 12 of the engine 11. The fuel injection nozzle 27 is connected with an electromagnetic valve 28 which is duty controlled by the electronic control unit 18, and fuel is injected from the fuel injection nozzle 27 to the combustion chamber 12 through the electromagnetic valve 28. Thus, the electronic control unit 18 controls the valve opening time of the electromagnetic valve 28 according to the detection result of intake air amount from the air flow sensor 17 to supply fuel of the corresponding amount, thereby setting the air/fuel ratio of the combustion chamber 12 to a predetermined value.
An ignition plug 29 located in the combustion chamber 12 of the engine 11 is connected to a distributor 32 incorporating an ignition coil 30 and a power transistor 31. Off operation of the power transistor 31 generates a high voltage in the ignition coil 30 to spark the ignition plug 29, and on operation of the power transistor 31 begins charging the ignition coil 30.
Therefore, in normal operation condition of the engine 11, air taken into the air intake passage 19 through the air cleaner 16 according to the opening of the throttle valve 20 is mixed with fuel injected from the fuel injection nozzle 27 to an adequate air/fuel ratio, the air/fuel mixture is ignited by the ignition plug 29 in the combustion chamber 12, and exhaust gas is discharged through an exhaust valve 35 from an exhaust passage 34 formed in the exhaust pipe 33.
In order to prevent the engine 11 from stalling at starting, this embodiment uses various sensors and switches in addition to the above-described air flow sensor 17 and idle switch 21, to control the open time of the needle valve 23 and the ignition timing of the ignition plug 29 according to signals from these sensors and switches. Specifically, the distributor 32 incorporates a crank angle position sensor 36 as engine speed detecting means for detecting rotational speed N E of the engine 11 and the crank angle position. Furthermore, a selector lever of the automatic transmission (not shown) is connected with an inhibitor switch 37 to detect whether or not the driver selects a forward or backward gear, that is, the driver intends to run the vehicle. In addition, the brake system incorporates a brake switch 38 for detecting whether or not the brake pedal (not shown) is pressed down. Furthermore, the acceleration pedal (not shown) is provided with an accelerator switch 39 to detect whether or not the driver's foot is on the acceleration pedal, that is, the driver intends to run the vehicle.
The accelerator switch 39 can be a touch switch attached to the surface of the acceleration pedal or a touch switch disposed between the vehicle body and the acceleration pedal utilizing a play of the acceleration pedal to the throttle valve 20.
Detection signals from these sensors 17 and 36 and the switches 21 and 37 to 39 are individually inputted to the electronic control unit 18, and, according to these signals, the electronic control unit 18 corrects the intake air amount and ignition timing of the engine 11 as needed.
Referring to FIG. 2 showing a control block of this embodiment, the electronic control unit 18 incorporates intake air amount increase calculation means 101, ignition timing correction calculation means 102 and ignition timing correction means 103. The electronic control unit 18 is inputted with detection signals from start preparation detecting means 104, start detecting means 105, and the crank angle position sensor 36 as engine speed detecting means 106. The intake air amount increase calculation means 101 outputs a duty signal corresponding to the intake air amount increase data to the solenoid 24 as a main device of intake air amount increasing means 107 of this embodiment. At the same time, the ignition timing correction calculation means 102 outputs a signal corresponding to the ignition timing correction data to the ignition timing correction means 103 which controls of ON/OFF timing to the ignition coil 30 through the power transistor 31.
The intake air amount increase calculation means 101 calculates the duty ratio of the solenoid 24 when idle speed control is stopped and the intake air amount to the engine 11 is increased. Specifically, although the duty ratio of the solenoid 24 can be changed at a time so that a predetermined target intake air amount is reached, in this embodiment, to prevent shocks due to an abrupt change in combustion condition of the engine 11, the duty ratio of the solenoid 24 is gradually varied so that the target intake air amount is reached in a predetermined period of time.
The ignition timing correction calculation means 102 calculates an ignition timing correction value to the engine 11 so that the intake air amount the ignition timing is retarded from that before increasing the intake air amount, at the same time the intake air amount to the engine 11 is increased, to suppress an increase in rotation speed of the engine 11 in association with increasing the intake air amount. Specifically, engine speed N I D for idle speed control plus a predetermined constant C is set as a target engine speed, and, when the current engine speed N E is higher than the target engine speed, that is, when the electronic control unit 18 determines that the engine speed N E is too high, the ON/OFF timing of current to the ignition coil 30 is controlled by the electronic control unit 18 through the power transistor 31 according to the detection signal from the crank angle position sensor 36 to retard the ignition timing of the ignition plug 29 by a predetermined value at a time.
In this embodiment an increase in rotation speed of the engine 11 associated with increasing intake air amount is prevented by retarding the ignition timing, however, alternatively, it is possible to prevent the engine speed from increasing by decreasing supply of fuel to the engine 11. In this case, fuel supply to the engine 11 can be reduced by controlling the current to the electromagnetic valve 28 of the fuel injection nozzle 27.
The start preparation detecting means 104 of this embodiment comprises the idle switch 21, the inhibitor switch 37, the vehicle speed sensor 40, the accelerator switch 39, and the brake switch 38. When it is detected from an ON signal of the idle switch 21 that the throttle valve 20 is fully closed, from an OFF signal of the inhibitor switch 37 that the selector lever of the automatic transmission selects a forward or backward gear, using the vehicle speed sensor 40 connected to the electronic control unit 18 that the vehicle is running at a very low speed of below 2.5 km per hour or in a stop condition, from an ON signal of the accelerator switch 39 that the driver's foot is on the acceleration pedal, and from an ON signal of the brake switch 38 that the brake pedal is pressed down, the electronic control unit 18 determines that the vehicle is in a start preparation condition.
One or more (e.g., detection signals from the accelerator switch 39 and the brake switch 38) can be removed from the detection conditions for the start preparation condition, but in such a case, control of the removed conditions becomes required, resulting in problems such as an impaired mileage. Since this embodiment is directed to a vehicle which incorporates an automatic transmission, a signal from the brake switch 37 is read as a detection condition for the start preparation condition. However, for a vehicle which incorporates a manual transmission, it is preferable to add a signal from a clutch switch for detecting a clutch off condition in place of the brake switch 37 as a detection condition for the start preparation condition. The clutch switch can be of a type which determines clutch on and off conditions from the clutch pedal position by a position sensor or a pair of touch switches.
When the start detecting means 105, which has the idle switch 21 and the brake switch 38, detects that the throttle valve 20 is not fully closed from an OFF signal of the idle switch 21 and that the vehicle is increasing the intake air amount and correcting the ignition timing according to the increase in intake air amount and the brake pedal is not pressed down from an OFF signal of the brake switch 38, the electronic control unit 18 determines that the vehicle is in a start preparation condition.
Referring to FIG. 3 showing the control flow of this embodiment, whether or not the vehicle is in a start preparation condition is determined from a detection signal from the start preparation detecting means 104 in step S1.
When the vehicle is determined to be in a start preparation condition in step S1, a start preparation flag F is set in step S2. In step S3, the electronic control unit 18 stops idle speed control of the engine 11, and controls increasing the intake air amount to the engine 11 through the solenoid 24 according to the calculation result of the intake air amount increase calculation means 101. After that, whether or not the ignition timing is corrected according to the increase in intake air amount in step S4.
At the initial stage, since the ignition timing is not corrected, the processing goes to step S5, in which the ignition timing is corrected in association with the increase in intake air amount by the ignition timing correction means 103 according to the calculation result of the ignition timing correction calculation means 102 to prevent the rotation speed of the engine 11 from increasing due to the increase in intake air amount.
When, in step S4, the ignition timing is determined to have been corrected according to the increase in intake air amount, it is determined in step S6 whether or not the current engine speed N E is greater than the engine speed N I D for idle speed control plus a predetermined constant C.
When it is determined in step S6 that the current engine speed N E is greater than the engine speed N I D for idle speed control plus a predetermined constant C, that is, the current engine speed N E is so high as to give an unusual feeling, the processing goes again to step S5, in which the ignition timing is corrected by the ignition timing correction means 103 according to the calculation result of the ignition timing correction calculation means 102.
When, in step S6, the current engine speed N E is smaller than the engine speed N I D for idle speed control plus a predetermined constant C, that is, the current engine speed N E is determined to be adequate, nothing is made and the control flow is ended.
When, is step S1, the vehicle is determined not in a start preparation condition, it is judged in step S7 whether or not the vehicle is in a start condition according to a detection signal from the start detecting means 104.
When, in step S7, the vehicle is judged to be in a start condition, in step S8, correction in step S5 of ignition timing in association with the increase in intake air amount in canceled. Then, in step S9, the electronic control unit 18 gradually decreases the intake air amount correction and ignition timing correction values to zero according to the time from the start preparation condition to the releasing. After that, the start preparation flag F is reset in step S10.
As a result, when the driver presses down the acceleration pedal to start the vehicle, since a sufficient amount of air to start the vehicle is already supplied to the engine 11, the vehicle can be started smoothly and rapidly according to the pressing-down amount of the acceleration pedal without stalling of the engine by only reverting the ignition timing back to the original advance angle.
When the fuel supply amount is corrected in place of the ignition timing, the correction values for the intake air amount and fuel supply amount can be gradually reduced to zero according to the time from the start preparation condition to releasing.
When, in step S7, the vehicle is determined as not in a start condition, the intake air amount increasing control and ignition timing correction associated with the increase in intake air amount are released in step S11, and the control flow goes to step S10.
The above-described control flow is executed in a shorter period than the signal at every 90 degrees from the crank angle position sensor 36.
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A stalling preventing appartus for an engine comprising intake air amount increasing means for increasing the amount of intake air to the engine from idling condition when the vehicle is in a start preparation condition, and rotation speed increase prevention means for preventing the engine speed from increasing due to the increase in intake air amount by the intake air amount increasing means, operation of the intake air amount increasing means and the rotation speed increase prevention means being stopped when the vehicle is in a start preparation condition, whereby a sufficient amount of air is supplied to the engine at starting of the vehicle and a delay in response of the air intake system to the pressing-down operation of the acceleration pedal is eliminated to increase the output torque of the engine at clutch-on and prevent engine stalling.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Provisional Patent Application No. 60/719,465, filed Sep. 22, 2005, which is hereby incorporated by reference herein in its entirety.
BACKGROUND INFORMATION
[0002] Session Initiation Protocol (SIP) is a call control signaling protocol for Internet Protocol (IP) networks. SIP is designed to be device-agnostic—that is, it is intended to provide a highly flexible call signaling capability that is not tailored to the capabilities of any particular device. Analog telephone signaling, on the other hand, is device-specific and highly constrained because of the historical legacy of the services delivered to the device. As a result, many call features available in traditional analog telephone devices are not easily integrated in a SIP-based network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] In order to facilitate a fuller understanding of the exemplary embodiments of the present inventions, reference is now made to the appended drawings. These drawings should not be construed as limiting, but are intended to be exemplary only.
[0004] FIG. 1 is an exemplary SIP-based network system, according to an embodiment of the present invention.
[0005] FIG. 2 illustrates an exemplary implementation where a SIP Device is embedded in a FTTP network, according to an embodiment of the present invention.
[0006] FIG. 3 illustrates an exemplary implementation where a SIP Device is embedded in an ATA device connected to an IP network, according to an embodiment of the present invention.
[0007] FIG. 4 is an exemplary flowchart illustrating a method for determining access to an audio port based on contact addresses, according to an embodiment of the present invention.
[0008] FIG. 5 is an exemplary flowchart illustrating a test and/or verification process, according to an embodiment of the present invention.
[0009] FIG. 6 is an exemplary flowchart illustrating a telemetry process, according to an embodiment of the present invention.
[0010] FIG. 7 is an exemplary flowchart illustrating a determination of relative priorities between dialogs, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] A system and process of an exemplary embodiment of the present invention provides the ability to recognize distinct contact addresses and invoke specific behavior based on the distinct contact addresses and further interact with normal voice calls.
[0012] FIG. 1 is an exemplary SIP-based network system, according to an embodiment of the present invention. System 100 illustrates an exemplary system for supporting SIP communication, in particular providing access to a SIP device based on a contact address associated with an invite request. As illustrated, SIP Device 110 may be coupled to User Interface 114 . SIP Device 110 may include a SIP User Agent 112 for communicating across IP Network 120 to a SIP Server 122 . SIP Server 122 may provide communication to other SIP devices, as shown by SIP Element 130 and SIP element 132 , through IP Network 124 . The various components of system 100 may be further duplicated, combined and/or integrated to support various applications and platforms. Additional elements may also be implemented in the system to support various applications. A SIP-based network may also include an IP network, packet switched based network or other type of network. The elements referred to in the Figures may include other network or packet switched based elements. For example, the elements referred to as “SIP” may include other network devices, elements, components, etc.
[0013] SIP Device 110 may represent a device that manages User Interface 114 . User Interface 114 may include a traditional telephone and other data communication device using voiceband or other signaling, including but not limited to data moderns, facsimile devices, teletype (TTY) equipment, etc. SIP Device 110 may contain SIP User Agent 112 . SIP User Agent 112 may be integrated with SIP Device 110 or remote from SIP Device 110 . SIP User Agent 112 may perform interworking between SIP signaling and user interface actions. For example, SIP User Agent 112 may manage an exchange of media (e.g., audio, etc.) between User Interface 114 and a Real Time Protocol (RTP) media stream of a media session set up by the SIP signaling. SIP Device 110 may originate calls to and receive calls from other users. SIP Device 110 may communicate through IP Network 120 to SIP Server 122 . In addition, SIP Device 110 may include a Network Port N for communicating through IP Network 120 and an Audio Port P for communication with User Interface 114 .
[0014] SIP Server 122 may represent a SIP proxy or application server that acts on behalf of SIP Device 110 . For example, SIP Server 122 may manage a SIP Address of Record (AOR) on behalf of SIP Device 110 . SIP Device 110 may register with SIP Server 122 and send SIP signaling through SIP Server 122 to other SIP elements, such as SIP Element 130 and SIP Element 132 . For example, a call to the SIP AOR may be delivered to SIP Server 122 , which in turn delivers the call to SIP Device 110 . SIP Server 122 may perform some service on behalf of SIP Device 110 , or may simply forward SIP messages to and from SIP Device 110 . SIP Device 110 communicates through IP Network 124 to SIP Element 130 and/or SIP Element 132 .
[0015] SIP Element 130 and SIP Element 132 may represent users with which the user of SIP Device 110 communicates. SIP Element may be a SIP Device, SIP Server, and/or other SIP enabled device. In addition, SIP Element may also represent a PSTN device that may be reached by a gateway that, directly or indirectly, acts as a SIP User Agent.
[0016] According to an embodiment of the present invention, SIP Device 110 may recognize various distinct contact addresses and provide corresponding distinct modes of access to Audio Port P. Access may include normal voice calling, verification access, test access, telemetry access and/or other access. In addition, priority rules may be implemented to grant access based on relative priorities determinations when a request is received during an established dialog.
[0017] FIGS. 2 and 3 show exemplary implementations of a SIP Device. FIG. 2 illustrates an exemplary implementation where a SIP Device is used in connection with a Fiber-to-the-Premises (MP) network, according to an embodiment of the present invention. FIG. 3 illustrates an exemplary implementation where a SIP Device is embedded in an Analog Telephone Adapter (ATA) which is used in connection with a traditional (e.g., electrical) IP-enabled access network, according to an embodiment of the present invention. Other implementations with other devices and/or networks may also be realized.
[0018] As shown in FIG. 2 , User Interface 114 may be connected to SIP Device 110 . SIP Device 110 may be embedded in Optical Network Terminal (ONT) 210 or otherwise integrated. ONT 210 may be connected to an Optical Line Terminal (OLT) 230 via a Passive Optical Network (PON) 220 acting as an access network for communications between ONTs 210 and OLTs 230 . According to an exemplary application, OLT 230 may be located at a Central Office. ONT 210 may be connected over PON 220 to the OLT 230 , which in turn passes that connection through transport IP network 120 to SIP Server 122 . According to an exemplary application, OLT 230 may maintain an IP connection between SIP Device 110 on the ONT 210 and the transport IP network 120 . In this exemplary application, the OLT 230 may not process SIP signaling, but rather allows SIP signaling to pass through to its destination.
[0019] FIG. 3 illustrates SIP Device 110 embedded in an Analog Telephone Adapter (ATA) 310 in a home or other location that subscribes to a broadband service delivered via an access network, such as DSL or cable modem service. The ATA device may be attached to a network, such as a broadband data network, IP network and/or other network. User Interface 114 may be connected to SIP Device 110 . ATA 310 may be connected to Broadband Router 320 , which in turn may be connected to a DSL or cable modern 330 , which in turn may be connected to access network 340 . Access network 340 may provide connectivity to transport IP network 120 through which the SIP Device 110 may communicate with SIP Server 122 . In one example, as shown in FIG. 3 , data multiplexer (MUX) 350 may provide a point of connection for transmissions between access network 340 and the transport IP network 120 .
[0020] The various components of systems 200 and 300 as shown in FIGS. 2 and 3 may be further duplicated, combined and/or integrated to support various applications and platforms. Additional elements may also be implemented in the systems described above to support various applications.
[0021] In an Internet Protocol (IP) network using the Session Initiation Protocol (SIP) for voice call control signaling, it may be desired to provide the equivalent of test, verification, and telemetry access to an analog telephone line (or equivalent) managed by a SIP User Agent. Such access may involve exchange of audio signals with the line, without normal call control signaling (e.g., power ringing, loop closure, etc.). An embodiment of the present invention provides a method and system for using SIP signaling to provide such access. Instead of relying upon protocols other than SIP, or on non-standard SIP extensions, an embodiment of the present invention may involve a SIP User Agent recognizing distinct contact addresses as having certain properties that invoke behavior appropriate for test, verification, telemetry and/or other access to an analog line. Further, an embodiment of the present invention minimizes and/or eliminates undesirable interactions with normal voice calls.
[0022] In the public switched telephone network (PSTN), an analog line that is normally used for originating and receiving voiceband telephone calls may at times also be accessed from the network for alternate purposes other than handling calls. Such alternative purposes may include test access, telemetry, busy line verification and/or other purposes. Test access may involve providing a connection from a test trunk to a subscriber line, for various manual and/or automatic testing purposes. Telemetry access may involve providing a connection to a telemetry device that shares a subscriber line (e.g., remote meter reading, etc.). Busy line verification access may involve providing a connection from a verification operator to a subscriber line for the purpose of determining whether there is conversation on a busy line or other activity. In addition, busy verification access may provide the ability for the operator to break into a call. These functions may be provided by a central office switch to loop-start analog lines.
[0023] The PSTN is evolving from its legacy technology base of analog and time-division multiplex (TDM) transport and signaling to a technology base using Internet Protocol (IP) transport and signaling protocols. However, the IP-based network will continue to support legacy analog subscriber equipment (e.g., analog phones, faxes, moderns). A mechanism for supporting analog equipment in the IP network may include a line media gateway deployed at the “edge” of the network, which uses IP signaling protocols that may be designed specifically for the gateway application. Gateway signaling protocols may operate at a relatively low level, and may thus easily support the functions of test access, busy line verification, telemetry and/or other alternate purposes with respect to analog subscriber equipment.
[0024] As IP signaling reaches more edge devices, SIP may be implemented as a call control signaling protocol for analog subscriber devices. For example, SIP signaling may meet analog subscriber equipment at devices such as Integrated Access Devices, Analog Telephone Adapters, and Optical Network Terminals. Such devices may manage one or more connections to analog devices, and may contain SIP User Agents that perform the translation between the analog line signaling expected by such analog devices and SIP protocol messages. In addition, SIP may also replace gateway control protocols in line media gateways. In contrast with gateway control protocols, which may be described as device control protocols, SIP may be considered a relatively high-level call control protocol.
[0025] As SIP is generally independent of the particular device used to originate and receive a call, SIP is typically not designed to provide direct access to an audio port of an edge device (e.g., the analog line) for purposes such as testing, busy line verification, or telemetry. An embodiment of the present invention provides audio port access for alternate purposes using standard SIP signaling.
[0026] An embodiment of the present invention may involve a device with a port to an analog user interface and a port to a network. The device may include SIP Device 110 which may include SIP User Agent 112 , as shown in FIG. 1 . A first port, as shown by Audio Port P, may be connected to one or more analog user interfaces, such as User Interface 114 . For example, User Interface 114 may include telephones or other communication devices, through which a user originates and receives calls as well as perform other form of communication. In addition, Audio Port P may also connect to one or more devices that may not be typically used to originate or receive calls, but may communicate using voiceband and/or other signaling to perform various functions, such as test, verification, telemetry, etc. A second port, as shown by Network Port N, may be connected to network 120 , which may include intermediate nodes (e.g., routers, switches, etc.). Network Port N may permit communication with a remote SIP element over network 120 . The remote SIP element may in fact be a point of connection to a network composed of many elements. For example, the remote SIP element may include a SIP Server 122 , a proxy server, an application server, a User Agent and/or other devices, including a SIP enabled device and/or other network enabled device. The remote SIP element may originate calls to and receive calls from SIP Device 110 using SIP signaling, such as described below. Using the method described in accordance with the various embodiments of the present inventions and embodied in SIP User Agent 112 in SIP Device 110 , the remote SIP element may also obtain access to Audio Port P for various purposes including testing, busy line verification, telemetry and/or other purposes.
[0027] SIP Device 110 may contain more than one Audio Port P, each such port capable of supporting at least one associated User Interface 114 . While the description and Figures illustrate a single audio port, additional audio ports, devices and/or components may be implemented. In addition, an Audio Port P may communicate with additional devices, such as multiple user agents, if such a configuration is desired. Further, the various elements may be further integrated, combined and/or separated across multiple components. Other architectures and scenarios may be implemented.
[0028] According to an exemplary scenario associated with a typical voice communication session, a remote SIP element may originate a call or other communication session to SIP Device 110 . The process may begin with a SIP INVITE message sent from the remote SIP element to SIP User Agent 112 in SIP Device 110 . The SIP INVITE message may be received by SIP Server 122 with which the SIP Device 110 has registered. The SIP Server 122 may perform address mapping and/or some admission control actions and forward the SIP INVITE to SIP Device 110 . Upon receiving the INVITE message, SIP User Agent 112 may alert the user by some form of signaling transmitted through Audio Port P to one or more user interfaces connected to Audio Port P, which may include an attached communication device. When alerting begins, SIP User Agent 112 may send a “180 Ringing” message to the remote SIP element. The user may respond by performing an action such as picking up a handset or other acknowledgement. The action may then cause the user interface to transmit a signal through Audio Port P to SIP User Agent 112 . In response, SIP User Agent 112 may send a “200 OK” message to the remote SIP element. The remote SIP element may then send an acknowledgement, e.g., ACK message, to SIP User Agent 112 . During the INVITE/200 OK/ACK exchange with SIP User Agent 112 , the remote SIP element may agree on audio session parameters. Upon reaching an agreement, the remote SIP element may exchange audio (or other data) between the device(s) attached to Audio Port P and an equivalent device at the remote SIP element. SIP User Agent 112 may track the state of the resulting call session. Eventually, one party may end the call by taking an action that results in a BYE message being sent. The element receiving the BYE message may respond with a “200 OK” message. A call originated by SIP Device 110 may begin with the user performing an initiation action, such as picking up a handset and dialing a number, whereupon SIP User Agent 112 in SIP Device 110 sends an INVITE message to SIP element. The call proceeds as described above, with SIP element and SIP Device 110 swapping roles.
[0029] The SIP User Agent 112 may manage more than one dialog simultaneously on behalf of Audio Port P. If multiple dialogs exist, some may be “on hold” and others may be “active.” If more than one dialog is active, the audio for the dialogs may be mixed, thereby forming a conference. Audio Port P may support a single audio stream or multiple audio streams which may be switched from one dialog or a set of dialogs to another dialog or another set of dialogs. Accordingly, in SIP Device 110 , Audio Port P may have no dialogs, one dialog or more multiple voice dialogs at any given time.
[0030] As noted above, a SIP dialog initiated by a SIP INVITE may correspond to a call and/or other form of communication between and/or among SIP devices and/or other communication devices. In the preferred embodiments described herein, a SIP dialog may not only include a typical voice dialog, but also a test dialog, a verification dialog, a telemetry dialog and/or other one-way or multiple-way communication of data specific to user interface equipment. In the preferred embodiment, SIP User Agent 112 may register a contact address with a “registrar” function in a SIP element (e.g., SIP Server 122 ). The contact address represents a unique address to which normal calls may be delivered. SIP User Agent 112 may also register alternate contact addresses associated with functionality supported by SIP Device 110 for interfacing with Audio Port P. For example, SIP User Agent 112 may register with its associated SIP Server 122 an address “A” which it may use for voice calling, an address “T” which it may use for telemetry sessions, and an address “V” which it may use for test/verification sessions. SIP User Agent 112 will interpret SIP INVITE messages directed to these addresses as requests for the special sessions that require alternate treatment, as further described below. Other addresses may also be used to represent other access, purpose or function, if such are provided by SIP Device 110 .
[0031] According to an exemplary application, test, verification, and telemetry access may be initiated by a remote SIP element and directed to the appropriate alternate SIP address associated with the SIP Device 110 . Upon receipt of the SIP INVITE directed to the alternate SIP address, SIP User Agent 112 may initiate an alternative session establishment process which accommodates the unique functionality of the requested service. For example, a test, telemetry or verification dialog may utilize means other than the usual and customary means for alerting and/or answering at analog devices connected to the Audio Port P of the SIP Device 110 . For example, the dialog may be established without providing a “ringing” signal to the user interface device—which may allow a telemetry device (or other device) attached to the Audio Port P to “answer” and communicate data. In addition, a test, telemetry or verification dialog may have a priority relationship with respect to other dialogs, such that it may be rejected in favor of other dialogs, and may also preempt or be preempted by other dialogs. Further, a test, telemetry or verification dialog may join with another dialog that is active, or may become active, at the audio port of the device. Other types of dialog may be established in accordance with the various embodiments of the present invention.
[0032] The preferred embodiments described herein may thus provide access to the audio ports of a SIP Device 110 via a SIP-established session, which may occur without disrupting the normal calling activities of the user and may accommodate the specific requirements of analog subscriber equipment.
[0033] FIG. 4 is an exemplary flowchart illustrating a method for determining access to an audio port based on contact addresses, according to an embodiment of the present invention. At step 410 , an INVITE request may be received at a device, such as a SIP User Agent 112 in SIP Device 110 . The INVITE request may be specific to a particular contact address. The contact address may include an address or any other identifier. At step 412 , a corresponding service supported by the SIP Device 110 may be identified for the contact address in the received INVITE request. For example, an INVITE to address “A” may be recognized as a request for a voice dialog at step 414 . As a result, a voice dialog may be established as shown by step 416 , in a manner that is well known. An INVITE to address “V” may be recognized as request for a verification dialog at step 418 and a verification dialog may be established as shown by step 420 (further described below). An INVITE to address “T” may be recognized as a request for a telemetry dialog at step 422 and a telemetry dialog may be established at step 424 (further described below). In addition, an embodiment of the present invention may receive INVITE messages to other addresses which may correspond to other services available on SIP Device 110 that have special processing requirements and/or provide other access. Step 426 represents an end of the process.
[0034] According to an embodiment of the present invention, priority rules may be implemented. The priority rules may apply when a request to establish a new dialog is received while a dialog is currently established. The existing dialog may be active, on hold or other status. For example, test and verification access to Audio Port P may involve connecting to an audio stream at Audio Port P regardless of the number of voice dialogs associated with Audio Port P. If no voice dialog is currently associated with Audio Port P, the test/verification audio stream may be a bidirectional exchange of audio with Audio Port P. If a voice dialog exists, then the test/verification audio stream may be mixed with the audio stream that exists between Audio Port P and a far end of the dialog. According to another example, telemetry access may involve a bidirectional exchange of audio with Audio Port P, making telemetry access to Audio Port P mutually exclusive with voice dialogs. Priority rules may arbitrate establishment of voice and telemetry dialogs in such cases. Other priority rules and/or conditions may also be applied.
[0035] FIG. 5 is an exemplary flowchart illustrating a test and/or verification process, according to an embodiment of the present invention. At step 510 , an INVITE to address V may be received. The INVITE to address V may be transmitted from a remote SIP element and received by a SIP User Agent in a SIP device which, for example, has registered address V as an address at which test/verification sessions with the Audio Port P associated with the SIP user Agent may be directed. It may be determined whether the INVITE to address V is properly authenticated, at step 512 . If it is not properly authenticated, the INVITE to address V may be rejected, at step 514 . At step 516 , it may be determined whether a verification dialog already exists associated with Audio Port P. If so, the INVITE may be rejected. In addition, other determinations may be made and the INVITE may be rejected for other reasons.
[0036] If a verification dialog does not already exist, the INVITE to address V may be accepted at step 520 . In addition, the INVITE to address V may be accepted at step 520 regardless of the existence of any voice dialogs. Once the INVITE to address V is accepted, a signaling process associated with test/verification processing may be executed in the course of establishing a test/verification session. For example, standard “ringing” signaling may not be provided on Audio Port P, but rather a media session for a verification dialog may be established, as shown by step 522 , thus allowing for test/verification signals to be applied at Audio Port P. If a voice dialog does not exist, as determined at step 524 , or any existing voice dialogs are on hold, as determined by step 528 , the media session established for the verification dialog may exchange bidirectional audio with Audio Port P, at step 526 . If one or more voice dialogs are active, as determined by step 530 , audio streams may be mixed, as shown by step 532 , such that the verification dialog receives audio from Audio Port P and active voice dialogs, and transmits audio to Audio Port P and active voice dialogs.
[0037] FIG. 6 is an exemplary flowchart illustrating a telemetry process, according to an embodiment of the present invention. At step 610 , an INVITE to address T may be received. The INVITE to address T may be transmitted from a remote SIP element and received by a SIP User Agent in a SIP device which, for example, has registered address T as an address at which telemetry sessions with Audio Port P associated with the SIP User Agent may be directed. It may be determined whether the INVITE to address T is properly authenticated, at step 612 . If not properly authenticated, the INVITE to address T may be rejected, at step 614 . At step 616 , it may be determined whether a telemetry or verification dialog already exists. If so, the INVITE to address T may be rejected, at step 618 . In addition, other determinations may be made and the INVITE may be rejected for other reasons. It may be determined whether a voice dialog exists, at step 620 . If not, the INVITE to address T may be accepted at step 622 . If a voice dialog exists, a determination of priorities between the current request and any existing dialogs may be initiated, at step 624 . Based on the priorities, the INVITE may be rejected at step 626 or accepted at step 628 . If the INVITE to address T is accepted, a signaling process associated with telemetry processing may be executed in the course of establishing a telemetry session. For example, standard “ringing” signaling may not be provided on Audio Port P, but rather specialized electrical signaling may applied at Audio Port P as may be expected by a telemetry device. If a telemetry dialog is established (e.g., the telemetry device responds), an associated media session may exchange bidirectional audio with Audio Port P.
[0038] FIG. 7 is an exemplary flowchart illustrating a determination of relative priorities between dialogs, according to an embodiment of the present invention. The relative priorities of telemetry and voice dialogs may determine which dialog takes precedence. The priority of a dialog may be specified by a “Priority” field in the header of the INVITE message that establishes the dialog. If a “Priority” field is not present, the priority may default to “normal” or other predetermined default. FIG. 7 illustrates an exemplary determination of priorities between or among dialogs. Other relative priorities may be established.
[0039] For example, when an INVITE, to address T is received while one or more voice dialogs exist, a determination of priorities may be made. At step 710 , if the priority associated with the INVITE to address T is less than or equal to that of at least one existing voice dialog, the INVITE to address T may be rejected, as shown in step 712 . According to an exemplary application, an INVITE to address T may have a lower priority than a voice dialog. However, if the INVITE to address T has a higher priority than existing voice dialogs, the INVITE to address T may be accepted at step 714 . If the voice dialog is active, as determined by step 716 , the active voice dialog may be placed on hold at step 718 and a telemetry dialog may be established as shown by step 720 . At this point, the user may not activate a voice dialog until the telemetry dialog ends. According to another example, an INVITE to address A may be received at step 722 during a time period when a telemetry dialog exists. The corresponding priorities of the requested call session and the existing telemetry session may be similarly compared. If the priority of the INVITE to address A is greater than the priority of the telemetry dialog as shown by step 724 , the telemetry dialog may be terminated at step 728 and the voice dialog may be established at step 730 . Otherwise, the telemetry dialog may continue as shown by step 726 , and the INVITE to address A may be rejected. Other priorities may be implemented in accordance with the various embodiments of the present invention.
[0040] While the processes of FIGS. 4 , 5 , 6 and 7 illustrate certain steps performed in a particular order, it should be understood that the embodiments of the present invention may be practiced by adding one or more steps to the processes, omitting steps within the processes and/or altering the order in which one or more steps are performed.
[0041] By recognizing the various distinct contact addresses, User Agent 112 in SIP Device 110 may provide corresponding distinct modes of access to Audio Port P, which may include normal voice calling, verification access, test access, telemetry access and/or other access. According to an embodiment of the present invention, User Agent 112 may provide these functions utilizing standard SIP signaling. As a result, SIP extensions are not required, non-standard protocols are not required, and protocols beyond those used for normal voice calling are not required. According to an exemplary application, standard SIP signaling may be used for providing verification, telemetry access and/or other access.
[0042] In the preceding specification, various preferred embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense.
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A method and system of an embodiment of the present invention may involve receiving an invite message at a network port of a device to initiate a communication session with the device; identifying an address associated with the invite message; when the address corresponds to a first address, performing a first session initiation process to establish first communications via an audio port of the device; and when the address corresponds to a second address, performing a second session initiation process to establish second communications via the audio port of the device; wherein the second session initiation process differs from the first session initiation process. In addition, access to the audio port may involve determining a priority of the invite message; rejecting the invite message when the priority of the invite message is inferior relative to a priority of a current dialog; and accepting the invite message when the priority of the invite request is superior to the priority of the current dialog.
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BACKGROUND OF THE INVENTION
The present invention is directed to a spray gun for delivering a compressible fluid from a discharge opening in the spray gun. The invention is also directed to a number of attachments that can be positioned on the spray gun to allow the spray gun to be utilized for different purposes.
Spray guns have been used in the prior art for dispensing different materials. Normally the spray guns are connected to a source of compressed air, such as a compressor, and the compressed air is used to dispense a material. Spray guns have normally contained a movable valve that is used to control the flow of compressed air through the spray gun. The compressed air generally moves through a discharge nozzle located on the spray gun and as the compressed air moves through the discharge nozzle it dispenses the material being handled by the spray gun. The material being dispensed by the spray gun is normally supplied to the spray gun in the region of the discharge nozzle.
Prior art spray guns are normally designed for a particular end use; such as spray painting. Different nozzles may be supplied with the spray gun for varying the pattern in which the material is dispensed from the spray gun but these different nozzles do not alter the basic purpose for which the spray gun was constructed.
Prior art spray guns have a needle valve located in the paint supply passageway for providing positive control to the supply of paint to the spray gun. The needle valve is displaced by the displacement of the trigger on the spray gun. The displacement of the needle valve allows paint to flow to the discharge end of the spray gun. When the trigger is released the needle valve is biased to cause the valve to close and shut off the flow of paint to the spray gun. The needle valve and trigger are arranged so that when the trigger is displaced air flows to the spray gun before the needle valve is displaced to allow paint to flow to the discharge end of the spray gun. When the trigger is released the needle valve closes and shuts off the flow of paint to the spray gun before the air flowing to the spray gun is shut off. The needle valve to control the paint supply and the operational sequence for the needle valve have been thought necessary to produce an acceptable spray pattern for a spray gun.
The prior art spray guns also do not have good controls for the supply of compressed air to the spray gun. When the trigger mechanism is displaced the compressed air is supplied to the gun until the trigger mechanism is released and the supply of compressed air is shut off. There is usually no provision in the trigger mechanism to regulate the supply of compressed air. Instead the trigger mechanism just provides an on-off type of control for the supply of compressed air to the spray gun.
There is a need for a spray gun that can be adapted for a number of end uses. Principally there is a need for a spray gun that will accept various attachments or nozzles that will allow the end use of the spray gun to be varied. In particular it is desirable to have a spray gun that is capable of discharging gases, liquids or particulate solids. In addition, there is a need for a spray gun that does not require a needle valve in the paint supply passageway to provide positive control for the supply of paint to the spray gun. Further it is desirable to have a spray gun where the supply of compressed air to the spray gun can be regulated.
SUMMARY OF THE INVENTION
According to the invention there is provided a gun for supplying a compressed fluid comprising a housing defining a passageway for supplying a compressible fluid. A valve means is moveably positioned with respect to said passageway for controlling the supply of the compressible fluid. The valve means defines an aperture and the valve means is moveable with respect to the passageway to vary the position of the aperture with respect to the passageway to control the supply of the compressible fluid. A discharge end is located on one end of the passageway. The discharge end is adapted to receive discharge nozzles for the gun whereby the compressible fluid acts as a driving fluid for different driven fluids or solids.
There is also provided according to the invention a number of attachments which can be utilized with the gun of the present invention.
A spray attachment for a gun for supplying a compressed fluid comprising a substantially cylindrical adapter is disclosed. One end of the adapter is positioned on the discharge end of the gun and the other end of the adapter defines a discharge opening. An aperture is defined in the wall of the adapter. A passageway is positioned in the adapter and the passageway is in communication with the aperture in the wall of the adapter. The passageway terminates in the discharge aperture. A chamber is defined in the adapter around the passageway. An air cap is positioned on the end of the adapter and the air cap extends from the periphery of the adapter to the discharge aperture in the passageway. At least one aperture is disposed in the air cap adjacent the discharge aperture in the passageway. The aperture defines a path of communication between the chamber and the discharge opening in the adapter. A source of paint or other suitable liquid is positioned in communication with the aperture in the wall of the adapter.
A washing attachment for a gun for supplying a compressed fluid comprising a substantially cylindrical conduit that defines a passageway is also disclosed. One end of the conduit is positioned on the discharge end of a gun for supplying a compressed fluid. A channel is positioned in the passageway at the other end of the conduit. One end of the channel terminates in an aperture. A valve means is movably positioned in the channel. One end of the valve means is capable of matingly engaging the portion of the channel adjacent the aperture. A source of cleaning material is positioned in communication with the aperture in the channel. An elongated member is connected to the conduit on the opposite side of the channel. The elongated member defines a first, a second and a third passageway. The first passageway is in communication with the channel in the conduit. The second passageway is in communication with the passageway defined by the conduit. The elongated member terminates in a discharge opening. The first, second and third passageways terminate in discharge apertures that are adjacent the discharge opening for the elongated member. An opening is defined in the wall of the elongated member. The opening is in communication with the third passageway in the elongated member. The opening is disposed for connection to a source of water.
The invention also includes a blasting attachment for a gun for supplying a compressed fluid comprising a substantially cylindrical adapter where one end of the adapter is positioned on the discharge end of the gun. An air tip is positioned in the adapter adjacent the discharge end of the gun. The air tip extends from the outer periphery of the adapter in a generally converging direction towards the center of the adapter. The air tip defines a discharged nozzle that is located substantially in the center of the adapter. A chamber is located in the adapter around the air tip. The chamber is in communication with the discharge nozzle in the air tip. An aperture is defined in the cylindrical adapter and the aperture is in communication with the chamber in the adapter. The aperture in the adapter is disposed for connection to a source of particulate blasting material. A blasting nozzle is positioned on the end of the adapter that is spaced apart from the gun. The blasting nozzle defines a passageway. One end of the passageway is positioned in alignment and in spaced apart relationship with the discharged nozzle in the air tip. The other end of the blasting nozzle defines a discharge aperture.
Further disclosed is a duster attachment for a gun for supplying a compressed fluid comprising a substantially cylindrical adapter and one end of the adapter is positioned on the discharge end of the gun. The other end of the adapter terminates in a discharge opening. The interior of the adapter defines a chamber. A generally converging wall portion is positioned in the adapter. The converging wall is positioned at the end of the adapter adjacent the discharge end of the gun. The converging walls define a nozzle having a discharge aperture and the discharge aperture is in communication with the chamber in the adapter.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view, partially broken away, of the gun for supplying compressed fluid of the present invention with a paint spraying attachment connected to the gun;
FIG. 1A is a cross sectional view taken along line 1A--1A in FIG. 1;
FIG. 2 is a cross sectional view taken along line 2--2 in FIG. 1;
FIG. 3 is a side elevation view of the gun of the present invention with a washing attachment connected to the gun;
FIG. 3A is a cross sectional view taken along 3A--3A in FIG. 3;
FIG. 4 is a partial cross sectional view of the washing attachment shown in FIG. 3;
FIG. 5 is a cross sectional view of the washing attachment taken along 5--5 in FIG. 3;
FIG. 6 is a cross section view of a blasting attachment that can be utilized with the gun of the present invention;
FIG. 7 is a cross sectional view of a duster nozzle attachment that can be utilized with the gun of the present invention;
FIG. 8 is a cross sectional view of another embodiment of the present invention;
FIG. 9 is a bottom view of the embodiment shown in FIG. 8;
FIG. 10 is a cross sectional view taken along line 10--10 in FIG. 8; and
FIG. 11 is a perspective view of an element of the embodiment shown in FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to a gun for supplying compressed fluid. Details of the invention will be more readily understood by referring to the attached drawings in connection with the following description.
The gun for supplying compressed fluid 1 has a handle 3 and a barrel 5. The handle 3 defines a passageway 7. The inlet end 9 of the passageway 7 has a connector 11 positioned therein. The connector 11 can be connected to a suitable source of fluid (not shown). Normally air under pressure will be supplied to the connector. The discharge end of the passageway 7 contains an aperture 15. The aperture 15 connects the passageway 7 to a bore 16 in the body of the gun. A spool valve 17 is slideably positioned in the bore 16. One end of the spool valve 17 is connected to a trigger mechanism 19. Movement of the trigger mechanism 19 controls the movement of the spool valve 17 in the bore 16. On the opposite end of the spool valve is a spring means 21 which biases the spool valve toward the trigger mechanism 19.
On the opposite side of the spool valve 17 from the aperture 15 there is a port 25. The port 25 is in communication with a passagway 27 located in the barrel 5 of the gun. The passageway 27 terminates in a discharge opening 29. The gun can also be provided with a hook 31 which can be used to hang the gun.
The spool valve 17 contains an obstruction section 35 that blocks the flow of fluid through the aperture 15. The spool valve 17 has an open section 37 that allows communication between the aperture 15 and the port 25. A wall 39 is positioned between the obstruction and the open sections of the spool valve. An O-ring seal 41 is positioned on the wall 39 to effectively seal the obstruction section 35 from the open section 37 of the spool valve 17. O-rings 43 can also be positioned at each end of the spool valve to provide seals at the end of the spool valve.
The spring means 21 biases the spool valve 17 towards the trigger mechanism 19 so that the obstruction section 35 of the spool valve is in alignment with the aperture 15. If the trigger mechanism 19 is moved toward the spring means 21 the spool valve 17 can be displaced so that the open section 37 of the valve is in communication with the aperture 15 and the port 25.
The aperture 15 located at the end of the passageway 7 has a substantially triangular cross section (see FIG. 2). The aperture is positioned so that the apex 47 of the triangular aperture is positioned close to and pointing towards the trigger mechanism 19. The base 49 of the triangular aperture 15 is positioned adjacent the spring means 21. The aperture 15 is positioned so the base 49 is substantially perpendicular to the longitudinal axis of the spool valve 17.
The discharge opening 29 can be provided with a threaded connection 55 positioned round its outer periphery to which a variety of nozzles for the gun can be attached.
Positioned around the end of the spring means 21 that is spaced apart from the spool valve 17 is a movable stop 61. The movable stop terminates in an end 67 that is positioned in the bore 16. The end 67 of the movable stop acts as a barrier surface to restrict the range of travel of the spool valve 17. The other end of the movable stop extends through an aperture 60 in the handle of the gun 1. One side 62 of the movable stop is flat and one side 59 of the aperture 60 is flat. The flat side 62 of the movable stop 61 engages the flat side 59 of the aperture 60. Threads 63 are positioned around the outer periphery of the stop 61. The threads 63 are engaged by a rotatable nut 65 that is positioned in the handle of the gun 1. The position of the end 67 of the movable stop 61 is controlled by the rotation of the nut 65. The engagement of the flat side of the movable stop with the flat section in the bore prevents the stop from rotating in the bore. Accordingly, as the nut is rotated the stop 61 will be advanced in the bore 16.
In operation the connector 11 at the inlet end 9 of the passageway 7 will be connected to a source of air under pressure. The compressed air passes through the connector 11 into the passageway 7. The compressed air will remain in the passageway 7 as long as the obstruction section 35 of the spool valve 17 is in alignment with the aperture 15 as the obstruction section effectively seals the aperture 15. If the trigger mechanism 19 is displaced towards the spring means 21 the spring means 21 will be compressed and the wall 39 of the spool valve will be moved towards the aperture 15. When the open section 37 of the spool valve 17 comes into communication with the aperture 15 and the port 25. Accordingly, compressed air will be able to flow through the aperture 15, through the open section 37 of the spool valve, through the port 25 and into the passageway 27 located in the barrel 5 of the gun. The compressed air can then be discharged through discharge opening 29 located at the end of the gun.
As the trigger mechanism 19 is displaced towards the spring means 21 a larger portion of the aperture 15 will come into communication with the open section 37 of the spool valve 17. The triangular configuration and position of the aperture 15 results in a larger and larger cross section of the aperture 15 to come into communication with the open section 37 as the spool valve 17 moves toward the spring means 21. Accordingly, the flow of compressed air through the aperture 15 will progressively increase as the trigger mechanism 19 is displaced towards the spring means 21 until the aperture 15 is in complete communication with the open section 37 of the spool valve 17.
When the trigger mechanism 19 is released the spring means 21 will cause the spool valve to be biased towards the trigger mechanism 19. Thus, the spool valve will move towards the trigger mechanism 19 until the aperture is in alignment with the obstruction section 35 of the valve and the aperture 15 is closed. As the spool valve 17 moves towards the trigger mechanism 19 the flow of air through the aperture 15 will be progressively decreased due to the triangular configuration and the position of the aperture 15.
The triangular configuration of the aperture 15 and the inter relation between the spool valve 17 and the aperture allows the flow of the compressed fluid to the gun to be very precisely controlled. Accordingly, the quantity or volume of the compressed fluid can be controlled by positioning the trigger to achieve the desired relationship between the triangular aperture 15 and the spool valve 17. In addition, the pressure of the compressed fluid being discharged from the discharge opening 29 in the barrel 5 of the gun can be controlled by controlling the flow of the compressed fluid through the aperture 15. Therefore, the pressure of the compressed fluid being discharged from the discharge opening 29 can be controlled without changing the pressure setting on the compressor supplying the compressed fluid.
The movable stop 61 can be used to control the range of movement of the spool valve 17. The end 67 of the stop 61 can be varied in position by rotating the nut 65 which engages the threads 63 on the stop 61. As the trigger mechanism is displaced towards the spring means 21 the spool valve will move towards the movable stop 61 until the end of the spool valve engages the end 67 of the stop 61. Thus, if the stop 61 is advanced towards the trigger mechanism 19 the displacement of the spool valve 17 towards the spring means 21 will be restricted. If the stop 61 is advanced away from the trigger mechanism 19 to the full extent the spool valve 19 will be free to move to its complete extent towards the spring means 21. The advantage of the movable stop 61 is that the stop can be positioned so the end 67 causes the spool valve to displaced only to the desired extent. During the use of the gun a particularly desirable level of flow of the compressed f1uid through the gun may be achieved. When this condition is achieved the nut 65 can be rotated so that the end 67 of the movable stop 61 will come in contact with the end of the spool valve 17. In this condition the trigger mechanism can be displaced until the spool valve strikes the end 67 of the stop and the desired flow level will be obtained. As the trigger mechanism cannot be displaced any further the trigger mechanism just has to be maintained at its position against the end 67 to maintain this desired spray level. If fine tuning of the spray pattern is required, this can be accomplished by rotating the nut 65 while keeping the trigger mechanism 19 fully depressed against the end 67 of the stop. The rotation of the nut 65 will vary the position of the spool valve with respect to the aperture 15 and change the volume of flow of compressed air through the aperture 15.
As shown in FIG. 1 a paint spray attachment 71 has been connected to the gun 1. The paint spray attachment has an adapter 73 which engages the threaded connection 55 on the barrel 5 of the gun. The adapter 73 has a nut 75 that engages the threaded connection 55 to secure the adapter to the barrel of the gun. The nut 75 and threaded connection 55 are usually constructed to be of a quick release variety requiring less than one turn of the nut 75 to disengage the adapter from the threaded connection. An aperture 77 is defined in the bottom of the adapter 73. The aperture 77 is in communication with a passageway 79 which is located in the interior of the adapter 73. The passageway 79 is defined by walls 81 which extend into the adapter 73.
A threaded connection 85 is positioned on the exterior of the adapter 73 in a position that is spaced apart from the discharge opening 29 in the barrel 5. An air cap 87 is positioned in the discharge end of the adapter 73. The air cap 87 is held in place by a quick release locking means 89 which engages the threaded connection 85 on the adapter 73. The air cap 87 has a member 91 which projects into the center of the adapter 73. The member 91 is connected to a nozzle 93 which is positioned in engagement with the walls 81 of the passagewav 79. The nozzle 93 defines a passageway 95 which is in communication with the passageway 79. A discharge aperture 97 is located at the end of the passageway 95 immediately adjacent the member 91.
The member 91 defines a first set of apertures 99 and a second aperture 101 positioned around the periphery of the nozzle 93. The apertures 99 and 101 are in communication with cavity 105 which is formed between the walls of the adapter 73 and the walls 81 of the passageway 79. The cavity 105 is in communication with the discharge opening 29 in the barrel 5 of the gun 1.
One end of a hose 111 is positioned in the aperture 77. The hose is secured to the aperture by means of a connector 113. The other end of the hose 111 passes through an aperture 115 located in the top 117 of a cup 119. The hose 111 normally extends substantially to the bottom of the cup 119. The top 117 is normally removably secured to the cup 119. A vent (not shown) is usually provided in the top to place the interior of the cup in communication with the atmosphere.
A bracket 123 is secured to one side of the top 117 of the cup 119. The bracket 123 is also removably secured to the handle 3 for the spray gun 1. The bracket 123 supplies a support which connects and supports the cup 119 with respect to the gun 1.
The operation of the paint spray attachment will be more readily understood by referring to FIG. 1 in connection with the following description. Paint or similar material is positioned in the cup 119. The hose 111 is positioned in the aperture 115 in the top 117 so that the hose extends into the cup 119. The top 117 is then secured to the cup 119 and the cup is secured to the handle 3 of the gun by means of the bracket 123. The hose 111 is then secured to the aperture 77 in the adapter 73 by means of connector 113. The vent in the cap prevents a vacuum from being created in the cup that would prevent the flow of paint from the cup. The gun is then ready to spray paint of similar material.
Compessed air is allowed to flow throuqh the passageway 7 into the passage 27 in the barrel 5 by activating the trigger mechanism in the manner previously described. The compressed air will pass through the discharge opening 29 in the barrel 5 and enter the adapter 73. The compressed air will enter the cavity 105 formed between the walls of the adapter 73 and the walls 81 of the passageway 79. The compressed air will be discharged through the first set of apertures 99 and the second aperture 101 located in the members 91. The flow of the compressed air from the aoerture 101, which is immediately adjacent the discharge aperture 97 in the nozzle 93, will create a zone of reduced pressure around the discharge aperture 97. The zone of reduced pressure will create a reduced pressure in the passageway 95 and the nozzle 93, in the passageway 79 and in the hose 111. The reduced pressure will cause paint to flow from the cup 119 into the hose 111 through the passageway 79 through the passageway 95 and the nozzle 93 and be discharged from the discharge aperture 97. As the paint or similar material leaves the discharge aperture 97 it will be engaged by the compressed air passing from the aperture 101. As the paint or similar material moves from the discharge aperture 97 it will also be engaged by the compressed air issuing from the apertures 99 located in the member 91. The position of the apertures 99 and the compressed air from the apertures 99 can be used to achieve a desired spray pattern for the paint issuing from the spray paint attachment 71.
The paint spray attachment is controlled by the supply of compressed air to the gun. The paint is drawn into the spray attachment in response to the reduced pressure in the passageway 95 in the nozzle 93 created by the flow of compressed air from the aperture 101 which is immediately adjacent the discharge aperture 97 in the nozzle 93. The extent of the reduced pressure is directly proportional to the volume and pressure of the compressed air being discharged from aperture 101. As the quantity and pressure of the compressed air being discharged from aperture 101 increases the reduction in pressure around the discharge aperture 97 also increases. Accordindly, the increased pressure reduction causes more paint to be drawn from the cup 119 and discharged from the discharge aperture 97. If the pressure and volume of the compressed air being discharged from aperture 101 is reduced there is not as large of a reduction of pressure around the discharged aperture 97 and not as much paint will be drawn from the cup 119 into the discharge aperture 97. Changes in the pressure and volume of compressed air supplied to the spray attachment also effects the discharge of compressed air through the apertures 99. Accordingly, the discharge of compressed air through the apertures 99, which help to establish the spray pattern for the paint issuing from the spray paint attachment, is also varied to be compatible with the quantity of paint being discharged from the discharge aperture 97. From the above it is clear that controlling the supply of compressed air acts to completely control the output of paint and the spray pattern of the spray attachment 71. The control is also self regulating as the supply of paint to the spray attachment and the spray pattern produced by the spray attachment are directly dependent upon the quantity and pressure of the compressed air supplied to the spray attachement. Therefore, as the quantity and pressure of the supply of compressed air are varied the quantity of paint supplied to the spray attachment and the spray pattern produced are varied in response to the change in the supply of compressed air. It is significant that the supply of compressed air can be controlled by controlling the movement of the trigqer mechanism on the gun. Accordingly, the output of paint and the spray pattern of the spray attachment are controlable by controlling the supply of compressed air delivered to the spray attachment.
FIGS. 3, 3A, 4 and 5 show a washing attachment 131 that can be connected to the gun 1. The washing attachment attaches to the discharge opening of the barrel 5 of the gun. A connector 133 can be used to secure the washing attachment to the threaded connection 55 located on the end of the barrel for the gun. The washing attachment comprises a conduit 134 defining a passageway 135 which is in communication with the previously discussed passageway 27 in the barrel 5 of the gun.
A valve means 137 is positioned in the passageway 135. The valve means defines a channel 139 and the channel terminates in an aperture 141. A cup 143 is positioned around the aperture 141 to the channel 139. The cup 143 can be held in position by a cap means 145 which is attached to the conduit 134 of the washing attachment 131. A vent 144 is provided in the cap 145. The vent defines a vent passageway 146. One end of the vent passageway is in communication with the atmosphere and the other end of the vent passageway is in commnication with the interior of the cup 143 when the cup 145 is secured to the cap. A tube 147 is positioned around the aperture 141 and extends into the cup 143. The tube extends to substantially the bottom of the cup 143.
A valve 151 is rotatably positioned in the channel 139. An O-ring seal 152 is positioned on the valve 151 to act as a seal between the valve and the channel 139. One end of the valve 151 is designed to seat in the channel 139 to stop the flow of material through the aperture 141 into the channel 139. The other end of the valve 151 contains a threaded portion 153 which engages a threaded collar 155 on the conduit 134. The threaded portion 153 of the valve 151 terminates in a knob 157.
An elongaged member 159 is attached to the conduit 134. The elongated member 159 can contain a threaded collar 161 which engages a threaded portion 163 on the conduit 134. The elongated member 159 defines a passageway 165 which is located substantially in the center of the member. The passageway 165 is in communication with the channel 139 in the valve means 137.
The elongated member 159 also defines a passageway 169. The passageway 169 is in communication with the passageway 135 which is in communication with the passageway 27 in the barrel 5 of the spray gun 1.
The elongated member 159 also defines a passageway 171. The passageway 169 is coaxial with the passageway 165 and the passageway 171 is coaxial with the passageway 169 and the passageway 165. Accordingly, the passageway 165 is located in substantially the center of the elongated member 159, the passageway 171 is located adjacent the outer wall of the elongated member 159 and the passageway 169 is located intermediate the passageway 171 and the passageway 165.
The elongated member 159 has a member 175 positioned on the exterior of the elongated member. The member defines an opening 177 at the end thereof and a passageway 179. The passageway 179 is in communication with the passageway 71 located in the elongated member 159. The exterior of the member 175 contains threads 181. The member 175 is normally connected to a source of water or other fluids that can be used in the washing attachment 131.
The elongated member 159 has a threaded portion 185 located at substantially the end of the elongated member. A threaded collar 187 is positioned around the periphery of the elongated member 159 to engage the threaded portion 185. The other end of the threaded collar 187 contains a threaded portion 189 which engages a threaded connector 191. The threaded connector 191 is connected to tube 193. The tube 193 is essentially an extension of the elongated member 159 and the tube forms the outer housing for the passageway 171, passageway 169 and passageway 165. The tube terminates in a discharge section 195 having a discharge opening 197. The discharge section 195 has a smaller diameter than the diameter of the tube 193. A converging section 199 is used to connect the smaller diameter discharge section 195 to the tube 193. The passageway 165 terminates in a discharge opening 167 that is located adjacent the discharge section 195 of the tube 193.
Rotation of the threaded collar 187 will cause the elongated member 159 to move with respect to the tube 193. Thus, the rotation of the threaded collar 187 will vary the length of the washing attachment 131. In effect, this will cause the discharge section 195 of the tube 139 to move with respect to the discharge opening 167 in the passageway 165 located in the center of the elongated member.
The passageway 171 terminates in an aperture 217 which is substantially adjacent the chamber 211. The aperture 217 is positioned at an angle so that the surface of the aperture can matingly engage the converging section 199 of the tube 193. The discharge opening 167 for passageway 165, the discharge aperture 213 for passageway 169 and the aperture 217 for passageway 171 all terminate in cavity 219 located in the tube 193. The cavity 219 is in communication with the discharge opening 197 from the tube 193.
The operation of the washing attachment 131 will be more completely understood by referring to FIGS. 3, 3A, 4 and 5 in connection with the following description. Compressed air is supplied to the gun 1 and passes through the gun by activating the trigger mechanism 19 as previously described. The compressed air is then discharged through the discharge opening 29 in the end of the barrel 5 of the gun. As the compressed air leaves the barrel of the gun it enters the passageway 135 in conduit 134. The compressed air will flow around the valve means 137 and enter conduit 169 which is in communication with passageway 135. The compressed air will advance through passageway 169 and into chamber 211 located at the end of the passageway 169. The compressed air will then pass through discharge aperture 213 located in the chamber 211. The discharge aperture 213 is located adjacent the discharge opening 167 for passageway 165. As the compressed air exits discharge aperture 213 it will create a region of reduced pressure being established in the passageway 165. Since the passageway 165 is in communication with channel 139 a zone of reduced pressure will also be established in channel 139. The reduced pressure in tube 147 will cause soap or other material from the cup 143 to be drawn into the tube 147 and into the channel 139. From the channel 139 the soap will pass into the passageway 165 and will be discharged through the discharge opening 167.
The flow of the soap from the cup 143 is controlled by valve means 137. As the knob 157 is rotated the threaded portion 153 of the valve 151 will be caused to advance in the threaded collar 155. The valve 151 can either advance towards or away from the aperture 141. If the valve advances away from the aperture 141 more of the channel 139 will be exposed and a larger quantity of soap from the cup 143 will be able to flow through the channel 135 into the passageway 165. If the valve 151 is advanced towards the aperture 141 the valve 151 will fill most of the channel 139 and restrict the flow of soap from the channel 139 into the passageway 165. If the valve 151 is advanced all the way towards the aperture 141 it will seat with the end of the channel 139 and completely cut off the flow of soap from the cup 143 into the channel 139. Therefore, by positioning the valve 15 in the channel 139 the flow of soap from the cup 143 into the passageway 165 can be controlled.
For the soap to flow from the cup 143, the cup must be vented to prevent a vacuum from being formed in the cup. Therefore, the vent 144 is essential for the proper supply of soap to the washing attachment. The vent can also be connected to a secondary source of soap (not shown) if desired. In this application, soap will be drawn from the secondary source into the cup 143 where the soap will be dispensed as desired to the washing attachment. Connecting the vent to a secondary source of soap allows the washing attachment to be used without stopping to refill the cup with soap.
Water can be supplied to the washing apparatus attachment 131 through opening 177 located in member 175. The water will pass through the opening 177 and into the passageway 179. Passageway 179 is in communication with passageway 171 and the water will therefore flow along passageway 171 until it passes through aperture 217 located at the end of passageway 171. Threads 181 have been provided on the member 175 for connecting a suitable source of water to the member 175.
The water discharged from passageway 171 through aperture 217, the air discharged from passageway 169 through aperture 213 in chamber 211 and the soap discharged through discharge opening 167 in passageway 165 are all combined in cavity 219 located at the end of the tube 193. The water and compressed air will act as a carrying means for the soap and this combination will pass through discharge section 195 and out discharge opening 197. The soap, water and compressed air can then be used for washing objects. The compressed air can be used to impart a higher velocity to the water passing through the discharge opening 197. This velocity can be much higher than the normal velocity of the water passing through passageway 71. The higher velocity for the water increases the effectiveness of the water in removing dirt from the object being washed.
The flow of the water through passageway 171 is controlled by the threaded collar 187 located on the elongated member 159 and tube 193. Rotation of the threaded collar 187 will cause the elongated member 159 to move towards the tube 193. The movement of the elongated member 159 will in effect change the combined length of the elongated member 159 in the tube 193. If the threaded collar 187 is rotated to reduce the combined length of the elongated member 159 and the tube 193 the converging section 199 will be moved towards aperture 217 in passageway 171. As the converging section 199 moves towards the aperture 217 it will restrict the flow of water from the aperture 217. If the threaded collar 187 is rotated far enough the converging section 199 will come into mating engagement with the end of the aperture 217 and completely shut off the flow of water from the passageway 171. If the threaded collar 187 is rotated to cause the combined length of the elongated member 159 and the tube 193 to increase the converging section 199 will move further away from the aperture 217 and more water will be allowed to flow from the passageway 171 through the aperture 217 into cavity 219. Accordingly, the rotation of the threaded collar 187 acts as a valve means to control the flow of water in the washing attachment.
The water and soap supplied to the washing attachment 131 can be completely shut off so that only compressed air will be discharged from the discharge opening 197. The compressed air can be used to clean items that are not suitable for cleaning with soap and water. Therefore, the washing attachment 131 can be used for a number of cleaning operations.
FIG. 6 shows the sandblasting attachment 225 which can be used with the gun of the present invention. The sandblasting attachment has an adapter 227 which attaches to threaded connection 55 on the barrel 5 of the gun. A quick connect threaded collar 229 can be provided on the adapter 227 to engage the threaded connection 55 on the barrel 5 of the gun. The adapter 227 is in communication with the discharge opening 29 in the barrel 5 of the gun. An air tip 231 is positioned in the adapter 227. The air tip 231 is conical in shape and extends in a converging fashion from the outer periphery of the adapter 227 to form a discharge nozzle 233. The discharge nozzle 233 terminates in chamber 235. The discharge opening 29 in the barrel 5, through the air tip 231, is in communication with a chamber 235 located in the adapter 227.
An aperture 237 is defined in the walls of the adapter 227 and the aperture is in communication with the chamber 235. The aperture 237 is constructed so that a suitable source of sand or other abrasive material can be connected to the aperture to supply the sand to the chamber 235. An arrangement as shown in FIG. 1 for supplying paint to the gun can also be utilized to supply sand or other abrasive material when using the sand blasting attachment 225.
The adapter 227 has a threaded portion 239 that is spaced apart from the collar 229. A blasting nozzle 241 is positioned in the end of the adapter 227 adjacent the threaded protion 239. A connector 243 can be provided on the blasting nozzle 241 to engage the threaded portion 239 on the adapter 227 to secure the blasting nozzle to the adapter. A protective liner 245 is positioned in the interior of the blasting nozzle 241. The protective liner defines a passageway 247 in substantially the center of the blasting nozzle 241. One end of the passageway 247 terminates in a discharge aperture 249. The opposite end of the passageway 247 has a flared or beveled opening 251 that is adjacent the discharge nozzle 233 of the air tip 231.
In operation compressed air will be supplied to the discharge opening 29 of the barrel 5. As previously described. The compressed air will enter the air tip 231 on the sand blasting attachment 225. The air tip will converge the compressed air and discharge it through discharge nozzle 233. The compressed air will then pass into the beveled opening 251 on the passageway 247 and be discharged from the sand blasting attachment through aperture 249 in the end of the blasting nozzle 241. As the compressed air exits the discharge nozzle 233 and enters the passageway 247 it will create a zone of reduced pressure in the chamber 235. The region or reduced pressure will create a reduced pressure in aperture 237 so that sand or other abrasive material can be drawn into the chamber 235 through the aperture 237 from a container (not shown). The sand or abrasive material will be drawn into the beveled opening 251 for the passageway 247 as the sand is entrained in the compressed air. The compressed air will act as the carrying fluid for the sand or abrasive material and will cause the sand to be discharged from the aperture with a velocity that is suitable for sand blasting. The protective liner 245 is positioned in the blasting nozzle 241 to act as a shield to keep the sand or abrasive material from destroying the interior of the nozzle. The protective liner can be a ceramic material or any other suitable material that can resist the abrasive character of the sand or other particulate material used with the blasting attachment 225.
FIG. 7 shows another attachment which can be used with the previously described gun. A duster nozzle 261 is shown connected to the barrel 5 of the gun. A threaded protion 263 can be provided on the duster nozzle 261 to secure the nozzle to the threaded connection 55 on the barrel 5 of the gun. The walls 265 of the nozzle 261 define a discharge opening 267 in the end of the duster nozzle. Apertures 269 can be provided in the walls 265.
The interior of the duster nozzle 261 is provided with generally converging walls 271 that form a nozzle 273 having a discharge aperture 275. The nozzle 273 and discharge aperture 275 provide a path of communication between the interior of the barrel 5 and the chamber 277 that is positioned in the duster nozzle 261 adjacent the discharge opening 267.
In operation compressed air will be supplied to the barrel 5 of the gun in the manner previously described. The compressed air will be directed into the nozzle 273 by the generally converging sidewalls 271 positioned in the interior of the duster nozzle 261. The compressed air will continue to be converged in the nozzle 273 until it passes through discharge aperture 275 into chamber 277. As the compressed air converges to move through the nozzle and discharge aperture 275 the velocity of the compressed air will be increased. Thus, the compressed air entering chamber 277 will be at a higher velocity than the compressed air in the barrel 5 of the gun. The high velocity compressed air will be discharged through discharge opening 267 and can be used to remove or move particulate material. As the high velocity compressed air moves through the chamber 277 an area of reduced pressure will be created in the chamber 277. Apertures 269 can be provided in the walls 265 of the duster nozzle 261. The apertures will allow ambient air on the exterior of the duster nozzle 261 to be drawn into the chamber 277 by the reduced pressure in the chamber 277. The ambient air drawn into the chamber will increase the volume of air discharged form the duster nozzle through the discharge opening 267. The apertures 269 also provide a safety release that will allow the compressed air to be discharged from the duster nozzle 261 of the discharge opening 267 becomes plugged for some reason. Thus, the apertures 269 improve the volume of air flow discharged from the discharge nozzle and also provide a safety feature for the duster nozzle.
FIGS. 8, 10 and 11 show a connection means 279 that can be used in place of the connector 11 shown in FIG. 1 to connect a supply of compressed air to the handle 3 of the gun. The connection means 279 is rotatably positioned in the passageway 7 located in the handle of the gun. The connection means has a generally cylindrical inner core 281. One end of the inner core has a larger diameter section 283 and the larger diameter section is positioned in the passageway 7. A groove 285 is positioned around the outer periphery of the larger diameter section. An O-ring seal 286 can be positioned in the groove 285 to provide a tight seal between the enlarged diameter section 283 and the side walls of the handle 3. The other end of the inner core 281 has a threaded section 287 to which a source of compressed fluid can be connected. A passageway 289 passes through the center of the inner core and places the passageway 7 in the handle 3 in communication with the source of compressed fluid that is connected to the inner core 281 at the threaded section 287. Positioned on the outer periphery of the inner core 281 are stops 290. The stops are positioned on the portion of the inner core 281 that is spaced apart from the handle 3 of the gun. The stops 290 extend from the surface of the inner core 281 a distance that is sufficient for the stops to engage the outer periphery of the walls of the handle 3 to prevent the inner core from being advanced too far into the passageway 7 in the handle 3. The portion of the inner core 281 located between the larger diameter section 283 and the stops 290 contains cutout sections 291 that are located on opposite sides of the inner core.
A removeable clip 293 is positioned around the inner core 281 in the region located between the larger diameter section 283 and the stops 290. The clip fits loosely around the inner core and the inner core is usually free to rotate with respect to the clip. The clip usually contains a split or break in one portion to allow the clip to be opened up to fit around the inner core. The clip has pivotally mounted flanges 294 positioned on opposite sides of the clip. The flanges extend from the base 295 of the clip and the flanges are substantially parallel to the sides of the inner core 281. Slots 297 are positioned along the sides of the flanges in the base 293 to improve the pivotal movement of the flanges. The flanges are positioned on the clip 293 so that the flanges can be pivoted and positioned in the cutout sections 291 on the inner core 281 of the connection means 279. The ends of the flanges 294 that are spaced apart from the base 295 contain projections 298 that extend from the outer periphery of the flanges. A step or shoulder 300 is located on the interior of the flange where the projection 298 joins the flange 294.
The removeable clip 293 also contains a tab 301 that projects from one side of the clip. The tab 301 has a substantially U-shaped configuration and defines a U-shaped groove 302.
When the connection means 279 is positioned in the passageway 7 in the handle 3 the projections 298 on the flanges 294 engage the apertures 305 located on opposed sides of the handle 3. The engagement between the projections 298 and the aperture 305 removeably engages the connection means 279 with the handle 3 of the gun.
To install the connection means 279 in the handle 3 of the gun the flanges 294 on the clip 293 are positioned in alignment with the cutout sections 291 on the inner core 281. In this position the flanges 294 are displaced or pivoted inwardly into the cutout sections 291 to allow the projections 298 to pass into the passageway 7 in the handle 3. When the projections 298 come into alignment with the apertures 305 the flanges pivot outwardly to their normal position and the projections 298 are positioned in engagement with the apertures 305. Once the flanges 294 extend outwardly to their normal positions the flanges are no longer positioned in engagement with the cutout sections 291. When the flanges are not in engagement with the cutout sections the inner core 281 is free to rotate with respect to the removeable clip 293. Since the inner core is free to rotate the inner core 281 can form a pivotal connection between the gun and the source of compressed fluid which is attached to the threaded section 287 on the inner core 281. The O-ring seal 286 provides a tight seal between the inner core 281 and the chamber 7 in the handle 3.
To remove the connection means 279 from the handle 3 of the gun the inner core 281 must be rotated until the cutout sections 291 are in alignment with the flanges 295. Suitable alignment indicators can be provided on the inner core 281 and the removeable clip 293 to facilitate this alignment procedure. When the flanges 294 are in alignment with the cutout sections 291 the flanges can be displaced inwardly into the cutout sections to disengage the projections 298 from the apertures 305 in the handle of the gun. When the projections 298 are disengaged from the apertures 305 the connection means 279 can be withdrawn from the passageway 7 in the handle 3.
A safety means has been provided to help prevent accidental disengagement of the connection means 279 from the gun. When the gun is being used and a source of compressed air is attached to the threaded section 279 the chamber 7 will be pressurized by the pressurized fluid. The pressure in the chamber 7 acts upon the inner core 281 and causes the inner core to move towards the end of the handle 3. The inner core can move towards the open end of the handle 3 until the larger diameter section 283 comes into contact with the step or shoulders 300 where the projections 298 join the flanges 294. When the large diameter section 283 engages the steps 300 the inner core 281 is prevented from further movement towards the end of the handle 3. Thus, during normal operation of the gun the larger diameter section 283 is in engagement with the steps 300 the portion of the projections 289 that extend from the step 300 are in abutting relationship with the larger diameter section 283. The abutting relationship with the larger diameter section prevents the projections 298 and flanges 294 from being displaced into the cutout sections 291 in the inner core 281. Thus, when the gun is being supplied with pressurized fluid the inner core 281 assumes a position with respect to the removeable clip 293 that helps to prevent the connection means 279 from being removed from the gun.
To remove the connection means the supply of pressurized fluid to the gun is terminated and the inner core 281 advanced into the chamber 7 in the handle 3 until the projections 298 no longer engage the larger diameter section 283. The projections 298 can then be disengaged from the apertures 305. This safety feature is designed to help prevent the connection means 279 from being accidentally disengaged from the handle 3 of the gun during the operation of the gun or during the period whem compressed fluid is being supplied to the gun.
FIGS. 8 and 9 show an embodiment of a securement means that can be used to detachably connect the lid of top 311 of a cup 313 to the handle 3 of a gun. A bracket 315 is connected to the lid 311 of the cup 313. A bracket 315 can be positioned in a cavity 317 located in the handle 3. The bracket 315 is designed to have a section 319 that is in contact with the wall 321 of the handle 3. The section 319 of the bracket 315 contains a projection 323. The projection is positioned to engage an opening 325 in the wall 321 of the handle 3 when the bracket 315 is properly positioned in the cavity 317.
A bore 331 is defined in a portion of the bracket 315. A generally cylindrical member 333 is rotatably positioned in the bore 331. One end of the cylindrical member 333 contains a head 335 having a diameter larger than the diameter of the cylindrical member. The head engages the surface of the bracket 315 adjacent the bore 331. The other end of the cylindrical member contains a rib 337. The rib extends from the cylindrical member 333 in a direction that is substantially perpendicular to the cylindrical member. The rib engages the portion of the bracket 315 adjacent the bore 331. On one end of the rib 337 there is a hook 339 that is positioned substantially perpendicular to the main portion of the rib. The hook 339 is positioned to engage the U-shaped groove 302 in the tab 301 on the removeable clip 293. One end of the U-shaped groove 302 has a cut away portion 341 to facilitate positioning the hook 339 in the U-shaped groove.
Connected to the cylindrical member 333 is a flange 343. The flange 343 is connected to the portion of the cylindrical member that extends from the cavity 317 in the handle 3.
The cylindrical member contains a cam surface 347 and a groove 349 positioned on one section of the cylindrical member. A projection 351 is positioned in the bore 331 where the projection can engage the cam surface 347 and the groove 349 on the cylindrical member 333.
The operation of the securement means for the lid 311 will be more fully understood by referring to the attached drawings in connection with the following description. To secure the lid 311 and the cup 313 to the handle 3 the bracket 315 is inserted into the cavity 317 in the handle. The section 319 on the bracket is positioned against the wall 321 of the handle with the projection 323 positioned in the opening 325. As the bracket 315 is positioned in the cavity 317 the rib 337 will be positioned so that the hook 339 is not in alignment with the U-shaped groove 302 and the tab 301. The broken lines in FIG. 9 show the position of the rib where the hook is not in alignment with the U-shaped groove. When the bracket 315 is properly positioned the flange 343 is rotated to cause the hook 339 on the rib 337 to come into engagement with the U-shaped groove 302. The cut away portion 341 of the U-shaped groove 302 will facilitate the engagement of the hook 339 with the groove. It should also be noted that the cylindrical member 333 will rotate in connection with the rotation of the rib 337.
As the rib 337 and the hook 339 are rotated to place the hook in engagement with the U-shaped groove 302 the cam surface 347 engages the projection 351. When the hook 339 is properly positioned in the groove 302 the cam surface 341 will have moved over the projection 351 and the projection is positioned in groove 349 on the cylindrical member 333. Thus when the hook 339 is in the desired location in engagement with the U-shaped groove 302 the projection 351 will be in engagement with the groove 349. The engagement between the groove 349 and the projection 351 maintains the cylindrical member 333 in this position and, therefore, maintains the hook 339 in engagement with the U-shaped groove 302. To disengage the hook 339 from the groove 302 it is necessary to supply a twisting force to the flange 343 that is sufficient to disengage the projection 351 from the groove 349 and cause the cam surface 347 to pass over the projection 351. Once the hook 339 has been disengaged, the projection 323 can be disengaged from the opening 325 and the bracket 315 removed from the cavity 317 in the handle 3. The force required to disengage the groove 349 from the projection 351 and cause the cam surface 347 to pass over the projection is sufficient to prevent accidental disengagement of the hook 339 from the U-shaped groove 302. Therefore, the projection 351, cam surface 347 and groove 349 act to maintain the cylindrical member 333, the bracket 315 and the cup 313 in the proper location with respect to the handle during the operation of the gun.
When the bracket 315 and cylindrical member 333 are properly positioned the projection 323 is secured in the opening 325 and the hook 339 is secured in the U-shaped groove 302. The projection and hook provide support to securely attach the bracket 315 and cylindrical member 333 to the handle 3 of the gun. Since the lid 311 and cup 313 are also secured to the bracket 315 the lid and cup are also secured to the handle 3 of the gun.
Having described the invention in detail and with reference to the drawings, it is understood that such specifications are given only for the sake of explanation. Various modifications and substitutes, other than those cited, can be made without departing from the scope of the invention as defined by the following claims.
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The invention is directed to a gun for supplying a compressed fluid having a housing defining a passageway for supplying the compressible fluid. A valve is moveably positioned with respect to the passageway for controlling the supply of the compressible fluid. The valve defines an aperture and the valve is moveable with respect to the passageway to vary the position of the aperture with respect to the passageway to control the supply of the compressible fluid. A discharge end is located on one end of the passageway. The discharge end is adapted to receive discharge nozzles for the gun whereby the compressible fluid acts as a driving fluid for different driven fluids or solids. There is also provided a number of attachments which can be utilized with the gun of the present invention.
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CLAIM OF PRIORITY
[0001] This application claims priority from Japanese application serial no. 2004-358111, filed on Dec. 10, 2004, the content of which is hereby incorporated by reference into this application.
FIELD OF THE INVENTION
[0002] The present invention relates to a fuel cell stacking method and a fuel cell stacking device for stacking fuel cells.
BACKGROUND OF THE INVENTION
[0003] A fuel cell stack is a structure composed by stacking a plurality of cells each consisting of a separator, an electrolyte membrane, an electrode assembly or a membrane electrode assembly (MEA), a gas diffusion layer and a gasket, and fitting to their ends terminal plates including a current collector plate, an insulator plate and a terminal holding plate. Although these parts are stacked by manual work at the developmental stage, once the specifications of the stack are fixed to enter into a mass production stage, an automatic stacking device becomes necessary.
[0004] Among the parts to be stacked, the separator and end parts are relatively thick and close to rigid bodies, the MEA and the gasket are made of soft thin films and, moreover, covered with protective sheets to protect their surfaces until immediately before stacking. The diffusion layer, differing from other parts in external dimensions, has to be accurately stacked over the electrode portion of the MEA.
[0005] When these parts are to be stacked by hand, the assembling method that is used is to first stack them in their approximate positions, finely adjusting their positioning with tweezers or the like, and pressing a guide rail against them sideways at intervals of a few cells to align the parts perpendicularly. Aligning them perpendicularly is synonymous to correcting intricate positional deviations of the parts.
[0006] On the other hand, there also is a case, as described in Patent Document 1, wherein projections and holes are provided in the separator and other parts to structure them to be free from positional deviation. In a mass production process, a device is needed to automatically stack these parts differing in properties with high accuracy. Although Patent Document 1 discloses a method of assembling solid high molecular electrolytic type fuel cells, but not their mass production method or a device for that purpose.
[0007] [Patent Document 1] Japanese Patent No. 3427915
[0008] Realization of an automatic stack system to handle both thick and heavy parts including the separator and thin film light parts including the MEA, realization of a function to peel off the protective sheets covering the MEA and others, and realization of an automatic stacking system accurately, efficiently and without damaging these parts is of vital importance to the mass production of fuel cell stacks.
[0009] A fuel cell stack is composed of thin and light parts such as the MEA, diffusion layer and gasket and thick and heavy parts such as the separator and terminal plates, and these parts are diverse in size. A challenge to be met is to work out a system to handle all of them and, as some of the parts have to be cleared of their protective sheets immediately before stacking, another challenge is to develop a pre-stacking treatment method. Still another challenge is to devise a system to stack these diverse parts with high accuracy.
[0010] An object of the present invention is to provide a stacking method and a stacking device suitable for mass production of high molecular electrolytic type fuel cell stacks.
SUMMARY OF THE INVENTION
[0011] The present invention provides a fuel cell stacking method for conveying stack members to constitute a fuel cell stack and stacking them in a prescribed sequence, comprising the steps of: moving each stack member to the prescribed stacking position thereof with a conveying robot; detecting the positions or shapes, for instance sides and/or apexes, of the stack members; aligning the positions of the stack members on the basis of the detected information; stacking the stack members with a stacking robot in a prescribed sequence; and fixing the stacked stack members.
[0012] The invention further provides a fuel cell stacking device for conveying stack members to constitute a fuel cell stack and stacking them in a prescribed sequence, comprising a conveying robot, a stacking robot, a guide rail for enabling each robot to move to the stacking position along a prescribed route, a unit for detecting the positions or shapes of the stack members, and a unit for aligning the positions of the stack members on the basis of the detected information.
[0013] According to the invention, it is possible to detect the positions or shapes of stack members and efficiently stack members of fuel cells by utilizing a conveying robot and a stacking robot, and thereby contribute to mass production of fuel cell stacks. In particular according to the invention, it is also possible to automate the stacking of fuel cell stacks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates the overall configuration of a device according to the present invention.
[0015] FIG. 2 illustrates the configuration of a parts handling unit.
[0016] FIGS. 3A to 3 D illustrate the configuration and actions of a gasket protective sheet peeling mechanism.
[0017] FIGS. 4A and 4B illustrate the configuration and actions of an MEA protective sheet peeling mechanism.
[0018] FIG. 5 illustrates the configuration of a fuel cell stack according to the invention.
[0019] FIG. 6 is a schematic profile illustrating the stacking state of the fuel cell stack according to the invention.
[0020] FIG. 7 is a schematic plan illustrating a stacking method for the fuel cell stack according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] A fuel cell stacking device for automatically stacking fuel cell stacks each consisting of a variety of parts is required to be compatible with the handling of those many different parts, to perform pre-stacking treatment matching the characteristics of each part and accurately adjust the stacking position. The handling mechanism can be compatible with diverse parts by handling thin and light parts with an electrostatic chuck system and thick and heavy parts with a suction chuck system. It can be adapted to different sizes of parts by doubly structuring the chuck units.
[0022] As the mechanism to peel off protective sheets, parts provided with warp prevention margins are used with highly repulsive protective sheets, and an end cutting system is used with less repulsive protective sheets. In order to accurately stack these parts differing in thickness and other dimensions, a system of optically detecting two apexes of each part is used.
[0023] The stacking device according to the invention has a supply zone comprising an area for supplying a small-number stack members and an area for supplying a large-number stack members, a stacking zone for stacking stack members, and a protective sheet peeling zone and a dust removing zone disposed between the supply zone and the stacking zone.
[0024] The stack members are divided into the large-number members and the small-number members, and can be accommodated into a tray for the large-number members and a tray for the small-number members, respectively. It is preferable for the handling unit of the conveying robot to have a handling subunit for lighter members and a handling subunit for heavier members, or to be replaceable.
[0025] The fuel cell stack may have a plurality of stacking device conveying robots and stacking robots. It is desirable for a member handling unit to have a small member handling subunit and a large member handling subunit or the handling unit to be replaceable with another unit having a required function.
[0026] It is further desirable for the fuel cell stacking device to have a mechanism for peeling off the protective sheets of stack members. It is desirable for the peeling mechanism to be equipped with a sub-mechanism or sub-mechanisms in one or more corners of each stack member, a sub-mechanism for cutting only an equivalent of the thickness of the protective sheet, a sub-mechanism for cutting only an equivalent of the thickness of a protective sheet on one side and double the thickness of the member itself, or a sub-mechanism for cutting only an equivalent of the thickness of the member itself. The peeling mechanism for protective sheets is disposed between the conveyance area and a stacking area.
[0027] It is preferable, with a view to preventing electrodes from being damaged or smeared, for the fuel cell stacking device to be provided with a mechanism which does not come into contact with the electrode portion of the MEA but chucks the electrolyte membrane around the electrode portion.
[0028] It is desirable for the fuel cell stacking device to be equipped with a dust removing unit for stack members between the conveyance area and the stacking area. It is desirable for dust to be removed from both upper and lower faces of each member either at the same time or separately. The dust removing mechanism can use blowing of gas, suction or electrostatic force.
[0029] It is desirable for members to be positioned for stacking by the stacking robot, for means to be provided for detecting the position of each member after it is stacked. As the device for the positioning of members for stacking and the detection of the position of each member after it is stacked, a laser system or an image sensing system can be used.
[0030] It is desirable for the inside of the hardware of the fuel cell stacking device to be a closed space to fill the closed space with dusted gas. It is preferable to provide a mechanism which can make the inside of the hardware a closed space and adjust the humidity and temperature of the gas in that space.
[0031] The conveying robot and/or the stacking robot can be equipped with mechanisms or a mechanism for adjusting the degree of acceleration/deceleration according to the length of the stroke of member shifting. It is desirable to provide stoppers or a stopper to prevent the members or member from straying in the shifting strokes or stroke of the conveying robot and/or the stacking robot.
[0032] Each robot arm is provided with a separate handling mechanism to enable the arm to handle both thick and heavy parts and thin film light parts. The suction chuck is used as the mechanism for handling thick and heavy parts, and the electrostatic chuck is used as the mechanism for handling thin film light parts.
[0033] Thin film parts having protective sheets include the MEA and the gasket. Though differing with the specifications of the part and with the manufacturer, the MEA is covered with protective sheets on both sides, while the gasket often has a protective sheet on only one side. The protective sheets of the MEA are not only thin, a few tens of μm in thickness, but also soft, the protective sheet of the gasket is not only thick, about 100 μm, but also highly repulsive. Therefore, they have to be handled with different mechanisms.
[0034] Where an MEA covered with thin and soft protective sheets on both sides, when one of its three-layered end is cut in a two-layer thickness and the three-layered end is pinched and pulled off, the protective sheet on one side is peeled off. After that, when another end is cut in a one-layer thickness and a two-layered end is pinched and pulled off, the MEA remains.
[0035] For a gasket provided with a thick and hard protective sheet on one side, a pinching margin is disposed a few mm beyond the size for use, a cut is made in advance into the gasket between the pinching margin and the real size and no cut is made into the protective sheet. When the pinching margin is pinched and the protective sheet is pulled off with the gasket being fixed with the electrostatic chuck, the protective sheet will come off the gasket.
[0036] In stacking the parts, an optical system is easier to use for accurate planar positioning. A laser system or an image sensing system can be used. In order to determining the planar position of a part, it is sufficient to detect the positions of two corners as shown in FIG. 7 . They may be two ends of a side or on a diagonal, or the positions of two sides may be detected as well. Where a corner is rounded or chamfered, the position of the corner point is in the space outside the part. To optically detect the position of such a point, the positions of the two sides crossing at that point can be figured out and the position of that intersection can be calculated on that basis. It is possible to secure accuracy with a tolerance of 1/100 mm to 5/100 mm, a sufficiently high level for the stacking of fuel cells.
[0037] According to the invention, an electrostatic chuck is used for the handling of thin and light parts and an air suction chuck for thick and heavy parts. Separate mechanisms are provided for the conveyance of parts and the stacking of parts. The protective sheet, if any, covering a stack part is peeled off with a mechanism matched with the structure of that part, and stacking positioning is performed by optically detecting two apexes of the part. Accuracy checkup of the stacked position is also carried out optically, with clean air delivered into the whole inside of the device, whose temperature and humidity are controlled, and each individual part being dusted. By providing the fuel cell stacking device with an accelerating/decelerating mechanism to accomplish conveyance and stacking and another mechanism to prevent deviation during conveyance, fuel cells can be automatically stacked with high efficiency and accuracy.
[0038] Next will be described the configuration of the fuel cell stack. FIG. 5 illustrates the basic configuration of the fuel cell stack. An MEA 50 is a portion where electric power generating reaction is caused to take place. The MEA 50 comprises electrodes 52 stuck to and integrated with the two sides of an electrolyte membrane 51 , which constitutes the substrate. On one side of each electrode, hydrogen gas, which serves as the fuel is made to flow and on the other side, air which serves as the oxidizer is made to flow. In order to diffuse the gas more readily to the electrodes 52 , diffusion layers 53 of about the same size as the electrodes 52 are so stacked as to cover the electrodes.
[0039] To seal the gas, gaskets 54 are so stacked as to cover the exposed parts of the electrolyte membrane 51 of the MEA 50 . The diffusion layers 53 are thereby arranged in the bored parts of the gaskets 54 . Further to form gas channels, separators 55 are stacked. This stacking sequence is repeated and, finally, terminal plates 56 are installed at both ends, and the whole assembly is fastened to finish the fuel cell stack.
[0040] Next will be described a mode in which the invention is implemented. As the forms of handling units, an electrostatic chuck is used for thin and light parts and a suction chuck, for thick and heavy parts.
[0041] As mechanisms for conveyance and stacking, arm-equipped robots are used. As the robot for conveyance use, a robot having long rails is provided so as to make possible collection of many different parts arranged in a extensive range, and as the for stacking use, a robot permitting highly precise control with a small operating range is provided so as to enhance the accuracy of stacking.
[0042] For each part covered with a protective sheet, a protective sheet peeling mechanism matching the structure of that part is provided.
[0043] In order to properly keep the conditions of the parts, the whole side of the stacking device is made a closed space, with clean air delivered into the whole inside of the device, whose temperature and humidity are controlled, and each individual part being dusted immediately before stacking.
[0044] In the positioning process before stacking, two apexes or the like of each part are optically detected, and the accuracy checkup after stacking is also optically accomplished by detecting the end positions in both perpendicular and horizontal directions. By combining these mechanisms, highly efficient and accurate automation of fuel cell stacking is achieved.
Embodiment 1
[0045] Before describing the fuel cell stacking device according to the invention, the stacked structure of fuel cells will be described. FIG. 5 shows a developed view of constituent elements of a high molecular electrolytic type fuel cell, wherein the basic configuration of the unit cell is a repetitions of the sequence of the terminal plates 56 (usually made of metal), the separators 55 , the gaskets 54 , the gas diffusion layers 53 , the electrodes 52 and the high molecular electrolyte 51 . Incidentally, the high molecular electrolyte 51 and the electrodes 52 in contact with its two faces are usually integrated and used by the name of a membrane electrode assembly (MEA).
[0046] In an actual fuel cell stack, as shown in FIG. 6 , an insulator plate 57 made of Teflon™ or the like and a highly electroconductive, for instance metal-made, current collector plate 58 are arranged adjacent to the terminal plates 56 and the separator 55 , respectively, outside the stacked body consisting of stack members as shown in FIG. 5 , and further a temperature measuring cell 62 having built-in thermometric means such as a thermocouple is arranged at intervals of tens of cells. Although the upper part of the stack configuration is shown in FIG. 6 for the convenience of illustration, in actual assembly of the stack various cell elements are stacked over the bottom terminal plate. The assembled stack is integrated and fixed together with the terminal plates with insulator pins or the like. In this way a fuel cell stack having tens of, for instance 80 , stacked units is composed.
[0047] FIG. 7 shows a plan of the terminal plate 56 . In assembling work with the stacking device, constituent elements are successively mounted on an assembling table 64 for instance and stacked. In that process, corner parts 61 of the terminal plates 56 and other constituent elements are optically detected, and the parts are so stacked as to align them with a preset center point 63 of the stacked cell. As a result, the terminal parts of the constituent elements may be out of alignment with one another as shown exaggeratedly in FIG. 6 . However, since the center point 60 of the stacked cell is predetermined and the parts are stacked with reference to it, priority is given to align the stack element with this center point.
[0048] FIG. 1 shows a preferred embodiment of the present invention. Referring to FIG. 1 , the cell stacking device, which is the preferred embodiment of the invention, comprises a conveyance zone A having trays 1 for a small-number members and trays 2 for large-number members, a protective sheet peeling zone B having protective sheet peeling units 7 and 8 , a dust removing zone C and a stacking zone D. The configuration of this embodiment will be described with reference to FIG. 1 . A fuel cell stack has many different kinds of parts, and the number of parts widely varies from one kind to another. To cope with this diversity, separate parts accommodating trays are disposed for different kinds. Further, trays for terminal plates and other parts whose number is small per kind and trays for parts whose number is large per kind are separately structured. In this embodiment, what belong to the small-number members are the terminal plates 56 , the insulator plate 57 , the current collector plate 58 and the temperature measuring cell 62 , and the other parts belong to the large-number members.
[0049] It is preferable for the trays 1 for small-number members, because they need not be very deep, to be of a turntable type to reduce the required motions of the conveying robot and thereby enhance the efficiency of work. The position where the conveying robot picks up parts is fixed, and the tray whose load is up for stacking is turned to the position of pickup by the conveying robot.
[0050] On the other hand, the trays for large-number members, which need to be deeper, is equipped with a bottom lifting mechanism to reduce the workload of the conveying robot. When the upper most part is picked up, a plate at the bottom of the tray rises by the thickness of one part. To keep constant the height of the pickup position, the position of the upper end of each part is sensed, and the bottom plate is raised until the part rises to that position. This combination of trays for the large-number members and trays for the small-number members eliminates waste in the conveyance of members, which is thereby enabled to be increased in speed.
[0051] The conveying robot 3 has a guide rail, namely a conveying robot guide rail 4 to cover all the parts trays and protective sheet peeling units and a dust removing unit to be described afterwards.
[0052] Parts with no protective sheet, namely the separator, the diffusion layer and the terminal plates are conveyed by the conveying robot 3 to apart's upper side dusting unit 10 . There, the conveying robot 3 temporarily frees the part to enable its upper side to be cleared of dust by electrostatic dusting, blowing or otherwise. After that, the conveying robot 3 conveys this part to a part's lower side dusting unit 11 to have its lower side to be cleared of dust by electrostatic dusting, blowing or otherwise.
[0053] A part with a protective sheet is carried to a protective sheet peeling unit before it is conveyed to the part's upper side dusting unit 10 , where it is cleared of the protective sheet. There are usually two kinds of parts with protective sheets, which are the gasket and the MEA. The gasket usually has a protective sheet on only one side, while the MEA normally has protective sheets on both sides.
[0054] The gasket having a protective sheet on one side is conveyed to the gasket protective sheet peeling unit 7 and, after being cleared of the protective sheet, carried to the part's upper side dusting unit 10 . The mechanism of the gasket protective sheet peeling unit 7 will be described afterwards.
[0055] The MEA having protective sheets on both sides is first conveyed to an MEA's upper protective sheet peeling unit 8 and, after being cleared of the upper protective sheet there, carried to an MEA's lower protective sheet peeling unit 9 , where it is cleared of the lower protective sheet. After that, it is carried to the part's upper side dusting unit 10 . The mechanism of the protective sheet peeling unit will be described afterwards.
[0056] After each part is dusted by the part's lower side dusting unit 11 , the conveying robot 3 places it on an intermediate mount 12 in preparation for its handing over to the stacking robot 5 . The stacking robot 5 picks up the part here, and carries it to a part's position adjusting unit 13 , where it is subjected to optical apex detection and the adjustment of its orientation to figure out the central position. After that, the part is conveyed to a stacking position 14 and, with its central position being aligned, descended to be stacked on the preceding part.
[0057] After stacking all the parts by repeating this sequence of actions, the mount, which is in the lowest stacking position, is carried along the guide rail to a stack pressing unit 15 , where it is pressed and fitted with fixing bolts. Then it is moved to a stack taking-out unit 16 , where it is carried out of the stacking device.
[0058] In the whole device, a closed space is formed by device partitioning walls 17 , and it is preferable to deliver clean air into the internal space to control its temperature and humidity and to minimize dust therein.
[0059] Each of the conveying robot 3 and the stacking robot 5 has a handling unit 30 for sucking parts. FIG. 2 illustrates the configuration of the mechanisms of the handling unit 30 . This handling unit 30 comprises two kinds of mechanisms, of which one is a chuck 31 for thick and heavy parts and the other, a chuck 32 for thin and light parts. A vacuum suction chuck, which is stronger in sucking force, is used as the chuck 31 for thick and heavy parts, while an electrostatic chuck is used as the chuck 32 for thin and light parts, because a vacuum suction chuck would suck the part into the chuck to invite its deformation.
[0060] The thin and light parts include the MEA 50 , the diffusion layers 53 and the gaskets 54 shown in FIG. 5 . The diffusion layers are of the size corresponding to the electrodes 52 of the MEA 50 , while the gaskets 54 are of the size corresponding to the exposed portion of the electrolyte membrane 51 of the MEA 50 . To make the mechanism of the chuck 32 for thin and light parts with these different sizes, the chuck is double-structured. Thus, it chucks the MEA 50 and the gaskets 54 only with its outside portion as indicated by Action A of the electrostatic chuck shown in FIG. 2 . On the other hand, it chucks the diffusion layers 53 only with its inside portion as indicated by Action B of the electrostatic chuck shown in FIG. 2 .
[0061] The thick and heavy parts include the separators 55 and the terminal plates 56 shown in FIG. 5 . In each separator 55 , gas channels are formed inside, namely in the portions matching the diffusion layers, which forbid suction. Therefore, the outside gas sealing portions are sucked. This state is represented by Action A of the suction chuck shown in FIG. 2 . On the other hand, the terminal plates, as they are usually heavy, may not ensure sufficient suction force with the outside gas sealing portions alone. Since the terminal plates are flat inside and relatively large in square measure, their whole inside portions are sucked. Action B of the suction chuck represents this state.
[0062] The gasket protective sheet peeling unit 7 peels off the protective sheet covering one face of the gasket. The mechanism of this action will be described. FIGS. 3A to 3 D schematically show the mechanism of peeling the protective sheet off the gasket.
[0063] Referring to the plan of a gasket 20 shown in FIG. 3A , three regions including a gasket for actual use portion 25 to be stacked into a fuel cell, a pinching margin 23 to be held by a protective sheet chuck portion 26 and a warp prevention margin 24 are disposed on the gasket side. The protective sheet side 22 is a single-sheet item. The gasket for actual use portion 25 is sucked by the electrostatic chuck 32 and the protective sheet is peeled off, with the pinching margin 23 being held by the protective sheet chuck portion 26 . Immediately before the end of the peeling action, the warp prevention margin 24 prevents the protective sheet from springing back, and the gasket for actual use portion 25 , as shown in FIGS. 3B through 3D , can go through removal of the protective sheet while remaining in a state of being properly sucked by the electrostatic chuck 32 . Without the warp prevention margin 24 , the moment the peeling action ends, the protective sheet would spring back by its repulsive force to cause part of the gasket for actual use portion sucked by the electrostatic chuck 32 to be peeled off, and thereby invite its suction in a wavy state. Providing the warp prevention margin 24 is effective means for preventing this trouble.
[0064] The mechanism of peeling off the protective sheets covering both faces of the MEA 50 will be described with reference to FIGS. 4A and 4B . Since the protective sheets of an MEA protective sheet-protected MEA 40 are thin and soft, they would exert no repulsive force unlike the gasket protective sheet. Therefore, no warp prevention margin 24 , which is required by the gasket protective sheet, is needed. A small pinching margin would be satisfactory, and no pinching margin 23 for the gasket protective sheet is needed. Therefore, a cut is made into the terminal part to form a pinching margin.
[0065] First, a cut of a double thickness, namely as thick as a lower protective sheet 42 and the MEA together, is made into the terminal portion of to peel off an upper protective sheet 41 as shown in FIG. 4A . And a triple thickness of the terminal portion is held with a terminal chuck 43 and the upper protective sheet 41 is peeled off. Next, to peel off the lower protective sheet 42 , a cut of a single thickness of the MEA 50 is made into the other terminal portion as shown in FIG. 4B , a double thickness of the terminal portion is held with the terminal chuck 43 , and the lower protective sheet 42 is peeled off. In this way, both protective sheets can be peeled off the two-side protective sheet-protected MEA 40 . Though a cut portion like a chamfer would remain at the terminal portion of the MEA 50 , if it measures no more than a few mm, it will have no adverse effect on the performance of the fuel cell stack.
[0066] As described above, the cell stacking device according to the present invention has mechanisms for automatically assembling a fuel cell stack consisting of a variety of parts. Further to keep the assembling environment suitable for stacking, partitioning to surround the whole device is provided, and the temperature and humidity inside are controlled, with clean air introduced into the inner space. Moreover, to enable the speed of assembling to be increased, the speed of the robot carrying constituent parts is made variable according to the distance of conveyance, and further a stopper to prevent deviation can be provided to prevent the chucked part from coming off the chuck during acceleration or deceleration.
[0067] The present invention can be used as equipment for the mass production of fuel cell stacks. While there are many different types of fuel cells ranging from the normal temperature type to the high temperature type, the invention can be equally applied to any stack having a planar cell structure.
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It is intended to efficiently accomplish stacking of members of high molecular electrolytic type fuel cells. The invention discloses a fuel cell stacking device for conveying stack members to constitute a fuel cell stack and stacking them in a prescribed sequence, comprising a conveying robot, a stacking robot, a guide rail for enabling each robot to move to the stacking position along a prescribed route, a unit for detecting sides and/or apexes of the stack members, and a unit for aligning the positions of the stack members on the basis of the detected information. The invention also discloses a relevant fuel cell stacking method.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of U.S. patent application Ser. No. 14/988,385 filed Jan. 5, 2016, titled, “LONG LASTING BREATH MINT”, which is a Divisional of U.S. patent application Ser. No. 14/276,905, filed May 13, 2014, titled, “LONG LASTING BREATH MINT,” which claims the priority of U.S. Provisional Patent Application No. 61/822,909, filed May 13, 2013, titled “SLOW-DISSOLVING ORAL COMPOSITIONS,” the contents of each of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] This application relates to breath mints. In particular, this application relates to a long lasting breath mint having a small size that is comfortable and unobtrusive in the mouth of a user for long periods of time.
BACKGROUND OF THE INVENTION
[0003] The quest for fresh breath spans over 4,000 years, including the chewing of spices—for example, cloves, anise (fennel) seeds, and cardamom, and herbs, for example, mint and parsley. Today, a vast array of chewing gum and candy mints are available for freshening breath and/or masking bad breath. Chewing gum has a negative public image in some societies, however, as well as the well-known problem of a limited flavor lifetime. The effectiveness of candy mints is limited by their lifetime in a user's mouth, which is often measured in minutes. Sugar is an ingredient in many candy mints, which promotes tooth decay and has a high glycemic index.
SUMMARY OF THE INVENTION
[0004] The long lasting breath mint of the invention is of a size and weight that can stay comfortably in place in the mouth of a user for long periods of time. The breath mint of the invention is preferably a tiny oral hydrophilic matrix time-release tablet that transforms to a gel over time. The gel facilitates and ability for the mint to stay comfortably in place in the mouth, adhering to the gum line, a partial, half dentures, full dentures or complete natural teeth, for 30 minutes to several hours, while dissolving. As the breath mint dissolves, the mint continuously releases and delivers flavor and ingredients, causing salivation and naturally refreshing the breath. In one embodiment, the mint additionally includes enhancements, such as Vitamin D, chromium picolinate, Xylitol, Vitamin B complex, melatonin, or other enhancements.
[0005] Compositions and methods of manufacturing provide slow-dissolving oral compositions, which permit the manufacture of dramatically smaller dosage forms than have been heretofore possible. For example, embodiments of the oral compositions in the form of microtablets adhere to a user's gum and dissolve over at least about 2 hours, whereas previous formulations would require tablets of over twice the weight to obtain the same lifetime. In some embodiments, a size, shape, and feel of the microtablet when adhered to a user's gum is so comfortable to the user as to be easily ignored, for example, while speaking. Some embodiments of the composition comprise at least one cellulose ether and alginate. Some embodiments are useful for freshening breath and/or reducing dry mouth. Some embodiments provide slow release of nutritional supplements, vitamins, or the like.
[0006] The flavorant of the invention is designed such that it allows a small amount of natural flavor in each tablet to pack a pleasant, cooling and long-lasting mint flavor or other flavor, greatly amplifying and extending this effect for the full multi-hour duration of the tablet.
[0007] Some embodiments provide method for freshening breath comprising administering the breath mint that adheres to a user's gum.
[0008] The breath mint of the invention uses ingredients that may be in powder or liquid form. In one embodiment, the powder form utilizes materials of various viscosities, particle size and particle size distributions that are mixed together. A direct compression method may be used to form the raw materials into tablets. In one embodiment, the powdered raw material utilizes different ingredients that range in size from 50 pm to 1190 um in size. A variation in particle size falling between a ratio of 1 and 24 results in improved flow during the formation and tablet forming process. The particle sizes may further fall between ratios of 1:16, 1:8, and 1:2.
[0009] A direct compression method is the preferred method to form tablets. Direct compression manufacturing equipment can range from small bench type models to large computerized models. Examples of some of the current manufacturers of direct compression tablet presses include: Stokes, Fette Compacting, Korsch, Kikusui, Manesty, B&D, IMA, Courtoy, and International Process and Packaging Technologies OPPT). Typically, tablets formed from these presses are formed using pressures of 200-10,000 PSI. The ideal compression strength to produce a tablet depends on a variety of variables such as viscosity of materials, selection of binders, size of tablet being formed, and the number of tablets being formed at the same time. The above-mentioned list is just a few of the variables that must be evaluated in the compression cycle to produce a tablet for an intended application.
[0010] The breath mint of the invention may be of various geometric shapes that fit comfortably in the mouth of a user. Example shapes include oval, round, flat, semi-flat, spherical, semi-spherical, triangular, semi-triangular, pyramid, and diamond. Other shapes may also be utilized.
[0011] One component of the mint of the invention is a binder. The selection of binder materials is critical to the production of a small long lasting breath mint that dwells unobtrusively in the mouth of a user. By selecting materials from various families of saccharides and their derivates, synthetic binders, and incorporating various gums, gelatins, and alginates and then by varying their molecular weights and viscosities, a carrier was developed that formed a gel upon contact with moisture.
[0012] Certain members of the family of polysaccharides (methycellulose (MC), hydroxypropylcellulose (HPC), hydroxypropylmethycellulose (HPMC) and others), gums, gelatins, and alginates contain hydrophillic side chains that partially dissolve to form a soft, weak hydrogel upon contact with water. By selecting the correct combinations of the above materials, the tablet of the invention generates a gel surface on the tablet after exposure of about a minute to the saliva of the mouth. The creation of this gel layer provides several desirable features including adhesion to mouth surfaces and long life of the mint by controlling a rate of dissolution of the mint core.
[0013] In some embodiments, the microtablet forms a segmented tablet in contact with moisture, the segmented tablet comprising an outer gel layer and a solid core.
[0014] The outer gel layer produced on the surface of the tablets upon exposure to saliva is moldable to selected mouth structure to achieve a complementary shape to adjacent mouth structures, which aids in placement of the tablet and provides the right amount of adhesion to a selected area of the mouth of a user without causing an unpleasant gummy mess within the mouth.
[0015] The outer gel layer controls the rate and the extent of exposure of the tablet core to moisture, thereby slowing the rate and extent of dissolution. The correct combinations of carriers and flavorants, combined with the correct compression during tablet formation results in tablets that slowly melt away over a minimum of thirty minutes up to several hours. The dissolution rate is dependent upon the selection and amount of binders that are used to compliment the active ingredients. The formation of the gel surface slows the dissolution process of the tablets as confirmed by paddle dissolution testing. The tablet of the invention preferably results in a minimum dwell time of thirty minutes. Even when sucked on in the oral cavity like other mints, the tablets of the invention melt over a thirty to ninety minute period and continuously deliver a pleasant flavor.
[0016] In one aspect of the invention, the composition dissolves in more than about 30 minutes as measured by a paddle test, in an aspect, the composition dissolves in more than about two hours as measured by a paddle test and, in an aspect of the invention, the composition dissolves in more than about four hours as measured by a paddle test.
[0017] The gel layer controls the rate and extent of penetration of moisture into the tablet and the rate and extent of migration of active ingredients out of the tablet to their target tissues. The penetration of saliva (moisture) into the matrix of the tablet and that migration of active ingredients out of the tablet is controlled by diffusion across concentration gradients. The first concentration gradient is between the saliva (moisture) of the mouth and the solid surface of the tablet. As saliva (moisture) is pulled into tablet a second concentration gradient is created at the tablet—saliva interface in the form of a gel. The formed gel has a lower concentration of active ingredients than the solid phase of the tablet but a higher concentration than the surrounding saliva (moisture) of the mouth. The gel's lower concentration of active ingredients results in a slowing of the diffusion process out of the tablet as explained by Fick's first law of diffusion and Chatelier's principle of equilibrium. Again, by choosing the right combination of binders and active ingredients, we are able to create the correct set of parameters that produce the gel with a desirable permeability.
[0018] The binder material is selected to not mask or impede a long lasting and appealing effect from the flavorant. By mixing appropriately selected carriers with a particular flavorant, an appropriate combination may be obtained that does not produce too powerful a flavor that could be offensive and potentially irritating to the oral mucosa. At the same time, sufficient flavor should be delivered to be pleasant to the taste and effective as a breath freshener.
[0019] By using a combination of binders in the tablet of the invention, i.e. saccharides, certain polysaccharides (MC, HPC, HPMC, etc.), gums, gelatins, and alginates, tablets may be created of various sizes and shapes that fit comfortably between the gum and cheek. Several forms and sizes fit well within this space of the mouth. Since the tablet surface forms a gel within minutes of being placed in the mouth, the tablet contours to the surface where it has been placed, allowing a user to locate the mint in the most comfortable location and in a location that is imperceptible to anyone other than the user.
[0020] Some embodiments include at least one flavorant. In some embodiments, the at least one flavorant includes peppermint. In some embodiments, the at least one flavorant includes xylitol. In some embodiments, the at least one flavorant includes N-ethyl-p-menthane-3-carboxamide.
[0021] By choosing the correct gel forming carriers to combine with matching flavors, the extent of the duration of the flavor emitting from the gel surface of the tablet may be matched for the duration of the dwell time of the tablet, e.g., from a minimum of thirty minutes to several hours. Not only does the gel control the release of the flavor but also the extent of the flavorant delivered, so the flavor derived from the tablet is neither diminished nor released in excess.
[0022] Carriers are selected that compliment particular enhancements, to enable the tablet of the invention additionally deliver the enhancements over an extended period and at a rate that allows for the optimal absorption of the enhancements through the oral mucosa. In combination with appropriate flavorants, any negative tastes that are inherent to the enhancements may be masked.
[0023] Some embodiments provide a slow-dissolving oral composition comprising a carrier comprising at least one cellulose ether and alginate. Some embodiments comprise from about 10% to about 60% by weight of the at least one cellulose ether and from about 40% to about 90% of the alginate.
[0024] Some embodiments provide a microtablet comprising a slow-dissolving oral composition comprising a carrier comprising at least one cellulose ether and alginate, wherein the microtablet, when adhered to a user's gum, dissolves over at least about 2 hours.
[0025] In some embodiments, the enhancement comprises at least one nutritional supplement. In some embodiments, the at least one nutritional supplement includes vitamin D3. In some embodiments, the at least one nutritional supplement includes chromium picolinate. In some embodiments, the microtablet is a breath mint. Some embodiments further comprise a nutritional supplement.
[0026] In some embodiments, the breath mint includes a flavorant, a sweetener, a neutraceutical, a beneficial agent or combinations thereof. In some embodiments, the flavorant is peppermint. In some embodiments, the sweetener is xylitol. In some embodiments, the neutraceutical is vitamin D3 and in some embodiments, the neutraceutical is chromium picolinate.
[0027] Preferred polysaccharides of the family of polysaccharides for the breath mint of the invention have a viscosity between 2 mPa's to 40,000 mPa's and 60,000 mPa's to 150,000 mPa's can be composed of either a high viscosity or low viscosity hydroxypropyl methylcellulose alone or a combination of either.
[0028] In one aspect, the carrier comprises (i) from about 30 to about 60 wt. % of a high viscosity hydroxypropyl methylcellulose (HMPC), in some embodiments from about 35 to about 55 wt. % of the high viscosity HMPC and, in some embodiments, from about 40 to about 50 wt. % of the high viscosity HMPC, (ii) from about 10 to about 40 wt. % of a low viscosity HMPC, in some embodiments, from about 15 to about 35 wt. % of the low viscosity HMPC, and in some embodiments from about 20 to about 30 wt. % of the low viscosity HMPC, (iii) from about 0.5 to about 25 wt. % of hydroxypropylcellulose (HPC), in some embodiments, 1 to about 20 wt. % of the HPC and in some embodiments, from about 5 to about 25 wt. % of the HPC and (iv) from about 5 to about 35 wt. % of an alginate, in some embodiments, in some embodiments, from about 10 to about 30 wt. % of the alginate and, in some embodiments, from about 15 to about 25 wt. % of an alginate, based on the weight of the carrier, where the total of the wt. %'s of (i)-(iv) equals 100.
[0029] In some embodiments, a weight of the microtablet is not greater than about 145 mg. In some embodiments, a diameter of the microtablet is not greater than about 6.4 mm (0.25 inch).
[0030] In one embodiment, an example weight of the tablet is between 50 mg to 350 mg.
[0031] In accordance with one aspect of the invention, the breath mint tablet, comprises (a) from about 10 to about 60 wt. % of a carrier, in some embodiments from about 20 to about 50 wt. % of a carrier, and in some embodiments from about 30 to about 40 wt. % of a carrier, (b) from about to about 40 to about 90 wt. % of an active ingredient; in some embodiments, from about to about 50 to about 80 wt. % of an active ingredient and, in some embodiments, from about 60 to about 70 wt. % of an active ingredient and (c) from 0 to about 20 wt. % of at least one conventional additive, based on the weight of the composition.
[0032] In some embodiments, the composition weighs from about 250 to about 130 mg, in some embodiments, the composition weighs from about 150 to about 135 mg, and in some embodiments, the composition weighs from about 170 to about 132.5. The weight of the mint is governed by the ability of the mint to be form fitting to a desired location in the mouth for remaining securely in place. The activated gel layers overcome resistive force caused by the weight of the mint applied to the contact area to keep the mint in static equilibrium. Therefore, the mass is preferably directly proportional to the adhesion force to keep the mint from moving.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The accompanying drawings, together with the specification, illustrate exemplary embodiments, and together with the description serve to explain the principles of these embodiments.
[0034] FIG. 1 schematically illustrates an embodiment of a compressed tablet of the invention.
[0035] FIG. 2 schematically illustrates an embodiment of a microstructure of the compressed tablet of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Particular embodiments of the invention are described below in detail for the purpose of illustrating its principles and operation. However, various modifications may be made, and the scope of the invention is not limited to the exemplary embodiments described below.
[0037] As used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a flavoring agent” or “a colorant” encompasses a combination or mixture of different flavoring agents or colorants as well as a single flavoring agent or colorant.
[0038] Embodiments of compositions disclosed herein provide exceptionally small oral dosage forms with long lifetimes. For example, some embodiments provide a slow-dissolving breath mint in the form of a microtablet with a diameter not greater than about 6.4 mm (0.25 inch) and a weight not greater than about 141 mg, which dissolves over at least about 2 hours when adhered to a user's gum, releasing flavor, freshening a user's breath, and moistening the user's mouth over the lifetime thereof. In contrast, typical slow release breath mints with similar lifetimes have over twice the weight. Furthermore, lifetimes of candy mints and the flavor release of chewing gums are typically measured in minutes rather than hours. Some embodiments of the microtablet further comprise enhancements, such as a nutritional supplement, a vitamin, a mineral, a coenzyme, a biologically active compound, or a combination thereof.
[0039] FIG. 2 schematically illustrates a proposed structure of an embodiment of the microtablet 100 . Without being bound by any theory, it is believed that each microtablet 100 comprises microscopic honeycomb-like cells 130 . As illustrated in FIG. 2 , each cell 130 comprises a carrier layer 132 , which includes a carrier, and a nucleus 134 , which includes substantially all of the one or more active ingredients. The carrier in the carrier layer 132 forms the gel layer 110 when contacted by moisture from a user's saliva. Cells 130 on the surface of the microtablet 100 protect cells 130 in the interior from the user's saliva. In FIG. 2 , surface cells 130 a in the process of dissolving are indicated by dashed lines. The active ingredients in the nucleus 134 remain dispersed in the gel layer 110 , and become exposed to the user as the outer surface of the gel layer 110 dissolves in the user's mouth. Consequently, the microtablet 100 exhibits a slow or controlled release of the active ingredients in the nucleus 134 and a long lifetime for the microtablet 100 .
[0040] In some embodiments, the carrier comprises at least one cellulose ether and alginate. As discussed above, the carrier forms an adhesive gel in contact with moisture. In some embodiments, the composition comprises from about 19% to about 39% percent of the carrier by weight. In some embodiments, the composition comprises from about 16% to about 32% of the at least one cellulose ether, and from about 3% to about 7%, of the alginate.
[0041] Examples of suitable cellulose ethers include, for example, methylcellulose, ethylcellulose, hydroxypropyl methylcellulose (hypromellose, HPMC), carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose (HPC), and the like, and combinations thereof Some embodiments, comprise hydroxypropyl methylcellulose. Some embodiments comprise hydroxypropyl methylcellulose and another cellulose ether.
[0042] Examples of suitable alginates include sodium alginate, potassium alginate, alginic acid, algin, and combinations thereof. It is believed that the alginate contributes to the adhesion of the microtablet to the user's gum.
[0043] In some embodiments, the active ingredient includes at least one flavorant. The at least one flavorant is of any type known in the art, for example, essential oils, natural flavorants, artificial flavorants, nature-identical flavorants, semi-synthetic flavorants, and the like. The at least one flavorant provides the composition with a desired flavor profile, for example, mint (spearmint), peppermint, cinnamon, wintergreen, licorice, citrus, lemon, orange, lime, vanilla, chocolate, strawberry, cherry, ginger, banana, and the like. Because flavor preferences vary by geography and/or culture, some embodiments of the composition comprise flavor profiles selected accordingly. Examples of suitable flavorants include menthol (peppermint) R-(-)-carvone (spearmint), methyl salicylate (wintergreen), cinnamaldehyde (cinnamon), anethole (hcorice/anise), vanillin (vanilla), and the like. In some embodiments, the at least one flavorant gives the composition breath freshening properties. In some embodiments, the at least one flavorant masks an undesired taste of another ingredient in the composition.
[0044] In some embodiments, the at least one flavorant includes at least one sweetener. Suitable sweeteners include natural sweeteners and artificial sweeteners. Suitable natural sweeteners include sugars, monosaccharides, disaccharides, sugar alcohols, and other natural sweeteners, for example, glucose, fructose, sucrose, xylitol, sorbitol, and stevia. Suitable artificial sweeteners include, for example, aspartame, sucralose, neotame, acesulfame, potassium, and saccharin. In some embodiments, the at least one sweetener includes xylitol, which has a low glycemic index, is non-cariogenic (does not promote tooth decay). In some embodiments, the at least one sweetener is xylitol.
[0045] In an aspect of the invention, a slow dissolving breath mint comprises (a) from about 10 to about 60 wt. % of a carrier, (b) from about to about 90 to about 40 wt. % of an active ingredient and (c) from 0 to about 20 wt. % of at least one conventional additive, based on the weight of the composition. In an aspect of the invention, the slow dissolving breath mint comprises (a) from about 20 to about 50 wt. % of the carrier, (b) from about to about 80 to about 50 wt. % of the active ingredient and (c) from 0 to about 20 wt. % of the at least one conventional additive, based on the weight of the composition. And in an aspect of the invention, the slow dissolving breath mint comprises (a) from about 30 to about 40 wt. % of the carrier, (b) from about to about 70 to about 60 wt. % of an active ingredient and (c) from 0 to about 20 wt. % of at least one conventional additive, based on the weight of the composition.
[0046] In one embodiment, the mint of the invention includes an enhancement that is a sensate agent. Sensate agents provide cooling, tingling, heat or the like. Representative cooling agents include, without limitation, carboxamides, menthol and ketals, and diols. In one aspect the cooling agent is a paramenthan carboxyamide agent, such as N-ethyl-p-menthan-3-carboxamide, known commercially as “WS-3”, N,2,3-trimethyl-2-isopropylbutanamide, known as “WS-23,” and mixtures thereof. Additional cooling agents include menthol, 3-1-menthoxypropane-1,2-diol known as TK-10 manufactured by Takasago, menthone glycerol acetal known as MGA manufactured by Haarmann and Reimer, and menthyl lactate known as Frescolat® manufactured by Haarmann and Reimer. Representative heating agents include, without limitation, capsaicin. Representative tingling agents include, include without limitation, cinnammic aldehyde.
[0047] The breath mint of the invention may be in the form of a microtablet (microtab), tablet, lozenge, pastille, troche, or dragee. In some embodiments, a microtablet is manufactured by directly compressing a powder form of the composition between dies. In some embodiments, the microtablet is coated, while in other embodiments the microtablet is uncoated.
[0048] To provide contact for the user, the breath mint of the invention is of a small size. In one embodiment, a longest dimension of the microtablet is about 10 mm, about 9 mm, about 7 mm, about 6 mm, 5 mm, or about 4 mm. In some embodiments, the microtablet has a diameter of about 6.4 mm (0.25 in). In some embodiments, a thickness of the microtablet is about 5 mm, about 4.9 mm, about 4.8 mm, about 4.7 mm, about 4.6 mm, about 4.5 mm, about 4.4 mm, about 4.3 mm, about 4.2 mm, about 4.1 mm, or about 4 mm. The microtablet dimensions or size is preferably sufficiently small to comfortably fit entirely between a user's inner cheek and gum. Preferably, the microtablet is sized sufficiently small as to be unnoticed by the user over its lifetime when adhered to the user's gum, for example, while speaking. The adhesion of the microtablet adheres to the user's gum to reduce migration thereof.
[0049] Some embodiments of the microtablet have a mass of less than about 250 mg, less than about 200 mg, less than about 190 mg, less than about 180 mg, less than about 170 mg, less than about 160 mg, less than about 155 mg, less than about 150 mg, less than about 145 mg, less than about 144 mg, less than about 143 mg, less than about 142 mg, less than about 141 mg, less than about 140 mg, less than about 139 mg, less than about 138 mg, less than about 137 mg, less than about 136 mg, less than about 135 mg, less than about 134 mg, less than about 133 mg, less than about 132 mg, less than about 131 mg, or less than about 130 mg.
[0050] In some embodiments, when the microtablet is adhered to a user's gum, it dissolves over the course of at least 30 minutes, at least one hour, at least two hours, at least three hours, at least four hours, at least five hours, at least six hours, at least seven hours, at least eight hours, at least nine hours, or at least ten hours. In some embodiments, the microtablet dissolves at a faster rate when administered in a different manner, for example, in a user's mouth but not adhered to the gum, where a user is likely to suck on the microtablet. For example, some embodiments that take at least about 2 hours to dissolve when adhered to the gum dissolve over from about 30 minutes to about 90 minutes when not adhered to the gum. In some embodiments, this slow dissolution or long lifetime of the microtablet provides a slow or extended release of one or more active ingredients thereof, for example, a flavor component or enhancement. Suitable flavor components include, for example, flavorants and/or sweeteners. Other examples of suitable active ingredients include enhancements, such as nutritional supplements, vitamins, minerals, co-factors, biologically active compounds, and the like.
[0051] In some embodiments, the active ingredient is a probiotic product making up 30 wt. % to 90 wt. % of the composition in addition to a minimum of 1 wt. % to 3 wt. % or greater of flavorant.
[0052] In some embodiments, moisture from a user's saliva activates an adhesive that allows the microtablet to adhere to the gum and converts a surface of the microtablet 100 into a gel layer 110 , as illustrated in FIG. 1 , thereby generating a segmented gel comprising an outer gel layer 110 and a solid core 120 . In some embodiments, the gel layer 110 forms over the course of from about 30 minutes to about 1 hour. As the microtablet 100 dissolves, the core 120 shrinks, the outer surface thereof adding to the gel layer 110 as illustrated in FIG. 1B . The gel layer 110 has several functions. The gel layer 110 improves the mouth-feel of the microtablet 100 , when attached to a user's gum, over the course of its several-hour lifetime compared with a completely solid formulation by cushioning the solid core 120 from the user's mouth, thereby contributing to the comfort of the microtablet. The gel layer 110 is also believed to control moisture diffusion from a user's mouth to the core 120 , thereby preventing premature disintegration of the microtablet 100 , and therefore is at least partially responsible for the long lifetime of the microtablet. The gel layer 110 controls diffusion of the one or more active ingredients into the user's mouth, and consequently, provides controlled release of flavor components, resulting in long-lasting flavor. In some embodiments, the gel layer 110 also adheres the microtablet to the user's mucosa and/or gum.
[0053] In some embodiments of the composition, enhancements may be provided, such as at least one nutritional supplement, vitamin, mineral, coenzyme, biologically active compound, or the like. Examples include acetyl L-carnitine, boswellia serrata extract, boswellia serrate resin, astaxanthin, benfotiamine, beta glucan, bergamot, black catechu heartwood, black currant, black rice, blueberry, boron, bromelain, calcium fructoborate, caffeine, chamomile, chinese skullcap root, chromium piccolinate, chondroitin sulfate, citrulline, cocoa, coenzyme Q10, copper glycinate, cordyceps, cranberry seed oil, curcumin, dang shen, DHA (docosahexaenoic acid), eleutherococcus senticosus , EPA (eicosapentaenoic acid), boswellia serrata extract, fisetin, vitamin B9, calcium fructoborate, (“amino butyric acid, gamma tocopherol, glucosamine sulfate, grape seed, holy basil, hops strobile, hydrolyzed milk protein, krill oil, L-camosine, lemon balm, L -arginine, L -theanine, lutein, magnesium, marigold flower, melatonin, curcumin phospholipid (Meriva® curcurmin phytosome, Thorne Research, Dover, Id.), methylsufonylmethane, n-acetylcysteine, nattokinase, niacin, niacinamide, omega-3 fatty acids, omega-6 fatty acids, omega-7 fatty acids, omega-9 fatty acids, low molecular weight polyphenol (Oligonol®, Amino Up Chemical, Japan), Panax ginseng , phosphatidylserine complex, pomegranate seed oil, potassium, quercetin, reishi, resveratrol, Rhodiola rosea (golden root), rutin, Salvia miltiorrhiza, sea buckthorn oil, Siberian ginseng, squid oil, taurine, tocopherols, tocotrienols, trypsin, turmeric, UC-II undenatured-type 2 collagen, Scutellaria baicalensis and Acacia catechu bioflavonoid extract (Univestin®, Unigen, Seattle, Wash.), valerian root, vitamin B complex, vitamin B3, vitamin B6, vitamin B12, vitamin C, vitamin D3, zeaxanthin, and zinc.
[0054] Some embodiments comprise an agent that provides a sensation to the user's mouth, for example, heating or cooling. An example of a heating agent is capsaicin. An example of a cooling agent is N-ethyl-p-menthane-3-carboxamide.
[0055] Some embodiments of the composition comprise other ingredients, for example, release agents, anti-caking agents, lubricants, and the like.
[0056] In an aspect of the invention, the carrier comprises (i) from about 30 to about 60 wt. % of a high viscosity hydroxypropylmethylcellulose (HPMC), (ii) from about 10 to about 40 wt. % of a low viscosity HMPC, (iii) from about 0.5 to about 25 wt. % of hydroxypropylcellulose (HPC), and (iv) from about 5 to about 35 wt. % of an alginate based on the weight of the carrier, where the total of the wt. %'s of (i)-(iv) equals 100. In an aspect of the invention, the carrier comprises (i) from about 35 to about 55 wt. % of the high viscosity HMPC, (ii) from about 15 to about 35 wt. % of the low viscosity HMPC, (iii) from about 1 to about 20 wt. % of the HPC and (iv) from about 10 to about 30 wt. % of the alginate where the total of the wt. %'s of (i)-(iv) equals 100. And in an aspect of the invention, the carrier comprises (i) from about 40 to about 50 wt. % of the high viscosity HMPC, (ii) from about 20 to about 30 wt % of the low viscosity HMPC, (iii) from about 5 to about 15 wt. % of the HPC and (iv) from about 15 to about 25 wt. % of the alginate, where the total of the wt. %'s of (i)-(iv) equals 100.
[0057] In an aspect of the invention, the high viscosity HPMC is defined as one having a molecular weight of 60,000 or greater. Suitable high viscosity HPMC's include, without limitation, Dow Methocel® cellulose ethers E4M CR, E10M CR, K4M, K15M, and K100M. In another aspect of the invention, a low viscosity HPMC is defined as one having a molecular weight of 50,000 or less. Suitable low viscosity HPMC's include, without limitation, Dow Methocel® cellulose ethers E5, E15LV, E50LV, AND K100LV.
[0058] In an aspect of the invention suitable HPC's include Ashland Klucel Nutra D®. Examples of suitable alginates include sodium alginate, potassium alginate, alginic acid, algin, and combinations thereof.
[0059] In some embodiments, the formulation is manufactured by blending the components to provide a powder, which is converted into microtablets, for example, by direct compression. In some embodiments, the tableting is performed under a relatively high pressure. Consequently, in those embodiments, the ingredients of the composition are selected for compatibility with the tableting conditions.
[0060] In one aspect of the invention, the breath mint additionally contains a colorant and/or other conventional additives. Suitable colorants include natural colorants, e.g., pigments and dyes obtained from mineral, plant, and/or animal sources. Examples of natural colorants include red ferric oxide, yellow ferric oxide, annattenes, alizarin, indigo, rutin, and quercetin. Synthetic colorants may also be used and may include an FD&C or D&C dye, e.g., an approved dye selected from the so-called “coal-tar” dyes, such as a nitroso dye, a nitro dye, an azo dye, an oxazine, a thiazine, a pyrazolone, a xanthene, an indigoid, an anthraquinone, an acridine, a rosaniline, a phthalein, a quinoline, or a “lake” thereof, i.e., an aluminum or calcium salt thereof. Useful colorants may be food colorants in the “GRAS” (Generally Regarded As Safe) category.
[0061] Some embodiments of the composition comprise other conventional additives, for example, release agents, such as magnesium stearate, anti-caking agents, lubricants, and the like.
[0062] In an aspect of the invention, the breath mint is formulated as a tablet, lozenge, pastille, troche, or dragee.
[0063] It is another distinct advantage of the invention, that in one aspect, the dimensions or size of the compressed tablet is sufficiently small so that it comfortably fit entirely between a user's inner cheek and gum. And in some aspects, the compressed tablet is sized sufficiently small as to be unnoticed by the user over its lifetime when adhered to the user's gum, for example, while speaking.
[0064] In an aspect of the invention, the breath mint is slow dissolving as measured by a paddle test. By paddle test is meant the following protocol:
[0065] Paddle Test
[0066] Fill a 250 ml beaker containing a stir bar with 200 ml of deionized water at pH 6.4.
[0067] Place the beaker inside a water bath (for example, inside a 600 ml beaker filled with ca. 50 ml of water) equipped with a temperature measuring device) (for example, a thermometer taped to the inside of the 600 ml beaker).
[0068] Place the entire apparatus on a hot plate stirrer (for example, a Corning Hot Plate Stirrer (Model PC—220)) and stir at 60 cycles per minute until the temperature of the water bath is equilibrated to 37C.
[0069] Once these conditions are stable (60 cycles/min, 37C), place 40 mg of the sample and measure the time it takes for the sample to dissolve.
[0070] In some embodiments, the compressed tablet dissolves in more than 30 minutes, as measured by the paddle test; in some embodiments, the compressed tablet dissolves in more than one hour, as measured by the paddle test, in some embodiments, the compressed tablet dissolves in more than three hours, as measured by the paddle test, in some embodiments, the compressed tablet dissolves in more than four hours, as measured by the paddle test, in some embodiments, the compressed tablet dissolves in more than five hours, as measured by the paddle test, in some embodiments, the compressed tablet dissolves in more than six hours, as measured by the paddle test; in some embodiments, the compressed tablet dissolves in more than seven hours, as measured by the paddle test; in some embodiments, the compressed tablet dissolves in more than eight hours, as measured by the paddle test; in some embodiments, the compressed tablet dissolves in more than nine hours, as measured by the paddle test; and in some embodiments, the compressed tablet dissolves in more than five hours, as measured by the paddle test.
[0071] In an aspect of the invention, moisture from a user's saliva may cause the compressed tablet to adhere to the user's gum. Without wishing to be bound by a theory of the invention, as illustrated in FIG. 1 , it is believed that the saliva converts the surface of the compressed tablet 100 into a gel layer 110 , thereby generating a segmented gel comprising an outer gel layer 110 and a solid core 120 . In some embodiments, the gel layer 110 forms over the course of from about 30 minutes to about 1 hour. As the compressed tablet 100 dissolves, the core 120 shrinks, the outer surface thereof adding to the gel layer 110 as illustrated in FIG. 2 . The gel layer 110 has several functions. The gel layer 110 improves the mouth-feel of the compressed tablet 100 , when attached to a user's gum, over the course of its several-hour lifetime compared with a completely solid formulation by cushioning the solid core 120 from the user's mouth, thereby contributing to the comfort of the compressed tablet. The gel layer 110 is also believed to control moisture diffusion from a user's mouth to the core 120 , thereby preventing premature disintegration of the compressed tablet 100 , and therefore is at least partially responsible for the long lifetime of the compressed tablet. The gel layer 110 controls diffusion of the one or more active ingredients into the user's mouth, and consequently, provides controlled release of flavor components, resulting in long-lasting flavor. In some embodiments, the gel layer 110 also adheres the compressed tablet to the user's mucosa and/or gum.
[0072] FIG. 2 schematically illustrates a proposed structure of an embodiment of the compressed tablet 100 . Without being bound by any theory, it is believed that each compressed tablet 100 comprises microscopic honeycomb-like cells 130 . As illustrated in FIG. 2 , each cell 130 comprises a carrier layer 132 , which includes a carrier, and a nucleus 134 , which includes substantially all of the one or more active ingredients. The carrier in the carrier layer 132 forms the gel layer 110 when contacted by moisture from a user's saliva. Cells 130 on the surface of the compressed tablet 100 protect cells 130 in the interior from the user's saliva. In FIG. 2 , surface cells 130 a in the process of dissolving are indicated by dashed lines. The active ingredients in the nucleus 134 remain dispersed in the gel layer 110 , and become exposed to the user as the outer surface of the gel layer 110 dissolves in the user's mouth. Consequently, the compressed tablet 100 exhibits a slow or controlled release of the active ingredients in the nucleus 134 and a long lifetime for the compressed tablet
[0073] It is another distinct advantage of the compositions disclosed herein that they provide exceptionally small oral dosage forms with long lifetimes. For example, some embodiments provide a slow-dissolving breath mint in the form of a compressed tablet with a diameter not greater than about 6.4 mm (0.25 inch) and a weight not greater than about 141 mg, which dissolves over at least about 2 hours when adhered to a user's gum, releasing flavor, freshening a user's breath, and moistening the user's mouth over the lifetime thereof. In contrast, typical slow release breath mints with similar lifetimes have over twice the weight. Furthermore, lifetimes of candy mints and the flavor release of chewing gums are typically measured in minutes rather than hours.
[0074] In some embodiments, the compressed tablet dissolves at a faster rate when administered in a different manner, for example, in a user's mouth but not adhered to the gum, where a user is likely to suck on the compressed tablet. For example, some embodiments that take at least about 2 hours to dissolve when adhered to the gum dissolve over from about 30 minutes to about 90 minutes when not adhered to the gum. In some embodiments, this slow dissolution or long lifetime of the compressed tablet provides a slow or extended release of one or more active ingredients thereof, for example, a flavor components or a nutritional supplement. In some embodiments, a compressed tablet is manufactured by directly compressing a powder form of the composition between dies. In one aspect, the compressed tablet is coated, while in another aspect the compressed tablet is uncoated.
[0075] In an aspect of the invention, the compressed tablet is manufactured by blending the components in a suitable blender, such as a high intensity ribbon blender to provide a homogeneous powder. The resulting powder is allowed to set for a period of time sufficient to permit entrapped air to escape. The deareated power is then pelletize in a conventional pelleting machine. In an aspect of the invention, the dearated powder is compressed at a pressure of from about 1,000 to about 7,500 psi and in an aspect of the invention, the dearated powder is compressed at a pressure of from about 2,000 to about 4,000 psi.
[0076] In some embodiments, the compressed tablet is coated, while in other embodiments the compressed tablet is uncoated.
Example 1
Breath Mint
[0077]
[0000]
Ingredient
Wt %
Natural peppermint powder
35.7
N-Ethyl-p-menthane-3-carboxamide
4.8
Xylitol
11.4
Sucralose
2.1
High viscosity hydroxypropyl methylcellulose
17.6
(Methocel 100K)
Low viscosity hydroxypropyl methylcellulose
8.8
(Methocel K4M)
Hydroxypropylcellulose
5.3
(Klucel Nutra D)
Sodium alginate
7.3
(Keltrone HVCR, NF)
Magnesium stearate
2.3
[0078] The ingredients were blended and tableted into 6.4 mm (0.25 in) diameter by 4.4 mm thick, 141 mg tablets. The tablets took at least about 2 hours to dissolve when attached to a user's gum.
[0079] A breath mint was prepared by blending the all the ingredients in a high intensity ribbon blender to provide a homogeneous powder. The resulting powder was allowed to set for twelve hours until the entrapped air escapes. The deareated powder was then pelletized in a pelleting machine at a pressure of from about 4,000 psi to produce a breath mint weighing 141 mg and having circular cross section with a diameter of 6.4 mm.
Example 2
Breath Mint
[0080]
[0000]
Ingredient
Wt %
Peppermint flavor
35.7
N-Ethyl-p-menthane-3-carboxamide
4.8
Xylitol
11.4
Sucralose
2.1
Hypromellose
26.6
Hydroxypropylcellulose
5.3
Sodium alginate
7.3
Magnesium stearate
2.3
[0081] Paddle Test
[0082] A paddle test was conducted to quantify the slow dissolution of the breath mint of the invention. A 250 ml beaker containing a stir bar and 200 ml of deionized water at pH 6.4 was placed inside a water bath (600 ml beaker filled with ˜150 ml of H2O). A thermometer was taped to the inside of the 600 ml beaker to monitor the temperature of the water bath. The entire apparatus was placed on a Corning Hot Plate Stirrer (Model PC—220). Stirring was set to 60 cycles per minute and the temperature of the water bath was equilibrated to 37C. Once these conditions were stable (60 cycles/min, 37C), the breath mint was placed in the 250 ml beaker as a timer was started and the start time was recorded in a lab notebook. It took over 18 hours for the breath mint to dissolve.
[0083] As a comparison, existing mints available on the market were also analyzed using a dissolution test. As can be seen from the test results below, the mints of the invention had a much greater life.
[0000]
ANALYSIS
METHOD
MDL
Dissolution
ARL 2.27*
1.0
ARL ID
Description
RESULT
UOM
106017
Mints of the
240
Minutes
invention
106012
Tic Tac Freshmints
26
Minutes
106016
Mintos
18
Minutes
106014
Altoids Wintegreen
17.75
Minutes
Small
106015
Breath Savers
16.5
Minutes
Peppermint
106013
Icebreakers
9.75
Minutes
Notes:
*60 cycles per minute, 37.4 C., pH 6.44.
[0084] Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.
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A long lasting breath mint including a carrier and a flavorant, wherein the carrier includes at least one of a high viscosity cellulose ether and a low viscosity cellulose either and an alginate. The carrier forms a gel upon contact with saliva. A tablet is placed in the mouth of user, whereupon the tablet is wetted with saliva. A surface of the tablet is converted to a gel resulting in a tablet having an outer gel layer and a core. The gel serves as an adhesive for adhering the tablet to mouth structure. The gel slows exposure of the core to moisture and also slows diffusion of flavorant into the mouth of the user with the gel resulting in a breath mint having an extremely long life prior to complete dissolution, e.g., greater than 30 minutes or longer.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for flexibly attaching a medical device to human tissue. In particular, the apparatus is used to flexibly secure the distal end of a defibrillation, sensing or pacing lead to cardiac tissue.
2. Related Art
Cardiac sensing and stimulation leads generally have a lead body forming a tube, an electrode tip located at the distal end of the lead body, and a flexible insulated conductor traversing the length of the lead body for carrying signals and stimulating pulses between the electrode tip and a cardiac stimulating or sensing device, such as a pacemaker, defibrillator or sensor. To best sense electrical signals from the heart or to stimulate the heart, the electrode tip must be maintained in contact with the cardiac tissue to be sensed or stimulated.
Typically, cardiac leads are inserted into the heart through the superior vena cava. The lead is then guided through the right atrium and into the right ventricle of the heart. The electrode tip is then secured to the cardiac tissue at the apex of the right ventricle or other portion of the heart such as the septum or atrium. There are a variety of known ways to maintain the electrode tip in contact with the cardiac tissue to be stimulated. One common method is to use tines to secure the electrode tip to the cardiac tissue. A second common method is to attach a sharpened fixation helix (i.e., a screw) to the distal end of the electrode tip. The fixation helix is then rotated and screwed into the cardiac tissue to be stimulated. The tines are a form of mechanically "passive" fixation, and the helix is a form of mechanically "active" fixation.
Fixation means are generally referred to as being either electrically active or electrically inactive. In the case of electrically active fixation, the fixation helix doubles as the electrode tip because the fixation helix is electrically connected via a conductor to the cardiac stimulating or sensing device. Thus, an electrically active fixation helix secures the lead to the cardiac tissue to be sensed or stimulated and also provides sensing or cardiac stimulation to the tissue.
In the case of electrically inactive fixation, the fixation helix is not electrically connected to the cardiac sensing or stimulating device. Instead, a separate electrode is affixed to the distal end of the lead body. A wire conductor in the insulated sheath electrically connects the electrode tip to the cardiac stimulating or sensing device. The fixation helix is used only to secure the electrode tip to the cardiac tissue to be sensed or stimulated, but the helix does not actually carry electrical current.
Several conventional methods have been used to attach the fixation helix to the cardiac tissue. In one implementation of the helix, the lead body is fixedly attached to the fixation helix. When the lead body is rotated, the fixation helix also rotates. Thus, the helix can be screwed into the cardiac tissue by rotating the body of the lead to which it is attached. In a second implementation of the helix, it is rotatably attached to the end of the lead so that it can turn freely with respect to the lead. To screw the helix into the cardiac tissue, a stylet having a screwdriver tip is inserted into the lead. The screwdriver tip of the stylet fits into a slot on the back side of the fixation helix for screwing the helix into place. In a third implementation of the helix, a conductor coil is used to rotate the fixation helix within the lead. The fixation helix is connected to the end of the coiled conductor. Thus, when the coiled conductor is rotated, the fixation helix also rotates.
The use of a sharpened fixation helix as a fixation device has a drawback. During insertion of the lead into the heart cavity, the sharpened end of the fixation helix may snag adjacent cardiac tissue. Thus, some conventional leads are made such that, during insertion of the lead into the heart cavity, the fixation helix is retracted into the lead body. Once the lead has been inserted into the heart cavity, a stylet is inserted into the lead body and is used to deploy the fixation helix for insertion into the cardiac tissue. The fixation helix is then screwed into the cardiac tissue by rotation of the entire lead body.
One problem common to all of the devices described above that use a conventional fixation helix is that the distal end of the lead body is relatively stiff due to the bulky housing of the lead body. Because the fixation helix itself is also rigid and forms an additional extension from the housing, the length and stiffness of the distal end of the lead body is further increased when the fixation helix is extended. After insertion into the cardiac tissue, the fixation helix is kept fixed, in a linear alignment, in relation to the lead body. This stiff, linear orientation allows for leverage forces from the lead to be transferred to the embedded fixation helix. Movement of the inserted fixation helix can result in damage and irritation to the cardiac tissue at the site of attachment. Typical heart wall motion or body motion, such as movement of limbs, may also cause the lead to exert forces on the fixation helix, which may cause irritation or inflammation of the cardiac tissue, or perforation of the heart wall.
Damaged or irritated areas of cardiac tissue often lead to the development of scar tissue or increased fibrous growth due to continuous inflammation. The presence of scar tissue at the site of the electrode changes the sensing characteristics of the lead due to the impedance of the scar tissue and may result in lead failure or may require additional stimulation to the cardiac tissue. Additional stimulation may result in a rapid decrease in the life of the battery used as the energy source for the cardiac stimulating device. Further, the presence of increased fibrous growth may result in increased difficulty of lead extraction.
Thus, an apparatus is needed that reduces the forces on the fixation helix after implantation so that lead movement will not cause movement of the fixation helix within the tissue.
SUMMARY OF THE INVENTION
The present invention provides a compliant fixation device for connecting a fixation helix to the distal end of a pacing or defibrillation lead. In each of the embodiments shown, a rigid torque transmission means is shown for enabling the user to rotate the fixation helix to implant the helix in a patient's cardiac tissue. The fixation helix can be designed in these embodiments to provide either an electrically active or inactive fixation. Once the fixation helix is implanted, the flexible qualities of the present invention minimize the moment that the lead body can apply at the site of fixation. Thus, movements of the lead are not transferred directly to the cardiac tissue surrounding the fixation helix. This reduces mechanical trauma to cardiac tissue and thereby decreases inflammation and fibrous growth around the fixation site.
In the preferred embodiment, the compliant fixation device includes a spring that connects a fixation helix to a distal end of a lead. The spring may be surrounded by a biocompatible, bioreactive material. This material maintains the spring in a rigid state for efficient torque transmission during implantation of the fixation helix. Once the material comes in contact with the patient's blood, the material "bioreacts" by either dissolving in the blood or reacting to the blood such that it softens and expands. This allows the spring to bend and flex freely, thereby absorbing movements of the lead and preventing movement from being directly transferred to the cardiac tissue surrounding the fixation helix.
In each of the other embodiments presented herein, a connector in a compliant fixation device connects the distal end of a lead to a fixation helix to decouple movement of the lead from the fixation helix after implantation. Thus, the present invention allows for efficient implantation of the fixation helix while reducing harm to the cardiac tissue after implantation.
BRIEF DESCRIPTION OF THE FIGURES
The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.
FIG. 1 is a partially sectional view of a lead 100 of the preferred embodiment;
FIG. 2 is an exterior view of the lead of FIG. 1;
FIG. 3 is a partially sectional view of the lead of FIG. 1 after being implanted in cardiac tissue;
FIG. 4 is a partially sectional view of a second embodiment of a compliant fixation device of the present invention;
FIG. 5 is a sectional view of a third embodiment of a compliant fixation device of the present invention;
FIG. 6 is a sectional view of a fourth embodiment of a compliant fixation device of the present invention;
FIG. 7 is a sectional view of fifth embodiment of a compliant fixation device of the present invention;
FIG. 8 is a sectional view of a sixth embodiment of a compliant fixation device of the present invention; and
FIG. 9 is a sectional view of a seventh embodiment of a compliant fixation device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention is now described with reference to the figures where like reference numbers indicate identical or functionally similar elements. Also in the figures, the left most digit of each reference number corresponds to the figure in which the reference number is first used. While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the invention. It will be apparent to a person skilled in the relevant art that this invention can also be employed in a variety of other devices and applications.
Referring to FIGS. 1-3, a distal end 110 of a lead 100 of the preferred embodiment is shown. Lead 100 has a lead body 120. Distal end 110 of lead 100 includes a spring or connector 130 and a fixation helix 140 having a first end 150 and a second end 160. First end 150 is slotted to receive a screwdriver stylet (not shown). The stylet is typically inserted into lead body 120 to aid in maneuvering distal end 110 into position inside a patient's heart. Once the stylet is inserted into lead body 120, the screwdriver tip fits into slotted first end 150 of fixation helix 140. As the stylet is rotated, the torque from the rotation of the stylet is transferred to fixation helix 140 via the meshing of the screwdriver tip and first end 150 to screw fixation helix 140 into a patient's cardiac tissue. Second end 160 of fixation helix 140 is sharpened to facilitate insertion into the cardiac tissue.
During implantation of lead 100 into the cardiac tissue, spring 130 is maintained in a rigid state by means of a bioreactive material 170. A bioreactive material dissolves or otherwise undergoes a physical change when it comes in contact with blood or other liquids. Material 170 surrounds spring 130 at distal end 110 of lead 100. Material 170 ensures that spring 130 remains substantially rigid during implantation to facilitate implantation of fixation helix 140 into the cardiac tissue. Material 170 may be made from a dissolvable material, such as mannitol (a blood soluble sugar) or polyethylene glycol (PEG), or any other biocompatible, bioreactive material. Any material used should remain in an undissolved state for a period long enough to allow implantation of fixation helix 140. Material 170 preferably should dissolve between 10 to 30 minutes after insertion of lead 100 into the heart cavity. However, any material that dissolves within 24 hours after insertion of lead 100 into the heart cavity is sufficient.
As an alternative embodiment, the spring 130 may be implanted without material 170 with the torque necessary for implantation being transmitted to the fixation helix 140 solely by a stylet. Conversely, if the material 170 is capable of transmitting a suitable torque for implantation, the lead may be implanted without use of a stylet. However, a stylet will probably be required for explant in most cases.
In a preferred alternate embodiment, material 170 is a hydrogel, such as polyethylene oxide (PEO). Typically, hydrogels remain a solid polymer during implantation of lead 100. Instead of dissolving after implantation, the hydrogel swells and softens upon contact with blood to provide flexibility around the area of the hydrogel. Ideally, a hydrogel that swells by two times its original volume may be used. This swelling and softening allows substantial flexible movement of distal end 110 of lead 100 after implantation and also prevents ingrowth of cardiac tissue from attaching to spring 130, thereby maintaining extractability of lead 100 should it need to be removed after chronic implant.
Lead 100 achieves electrically active fixation because spring 130 electrically connects fixation helix 140 to a cardiac stimulation device (e.g., a pacemaker or defibrillator). Spring 130 can be made from any fatigue resistant, biocompatible, electrically conductive material. In the preferred embodiment, spring 130 is made of a nickel-cobalt alloy, commonly referred to as MP35N wire, available from Fort Wayne Metals. Lead body 120 also includes an insulative sheath 180 that surrounds the coiled conductor. Insulative sheath 180 can be constructed from implantable polyurethane or silicone rubber or any other flexible, electrically insulating material that is biocompatible.
FIG. 3 shows lead 100 implanted into a patient's cardiac tissue 310. As shown in this embodiment, material 170 is dissolved so that spring 130 is allowed to freely bend and flex in response to forces on distal end 110 of lead 100 imparted by lead movement. Fixation helix 140 remains implanted in cardiac tissue 310 despite movements in lead 100.
It will be understood that the present invention can advantageously be used to affix a lead to other portions of the heart such as the intraventricular septum or to locations in the atrium.
FIG. 4 shows a partially sectional view of a second embodiment of a compliant fixation device 400 of the present invention. A lead body 120 is shown having a distal end 110. A fixation helix 140 is disposed at distal end 110. Fixation helix 140 has a first end 150 which is slotted to receive a screwdriver stylet. A second end 160 of fixation helix 140 is sharpened to facilitate insertion of the helix into a patient's cardiac tissue. In this embodiment, the connectors are a pair of silicone rods 410 attached to first end 150 of fixation helix 140. As described above with respect to the preferred embodiment, silicone rods 410 are surrounded by a biocompatible, bioreactive material 170. Thus, after implantation, material 170 either dissolves or softens as described above. This allows the flexible silicone rods 410 to be free to compensate for lead movements.
This embodiment provides electrically active fixation because silicone rods 410 may contain coiled conductors 420 or cables (not shown) to provide an electrical connection to fixation helix 140 thereby achieving active fixation. As another alternative, silicone rods 410 may be loaded with carbon or metal powder to provide an electrical connection to fixation helix 140.
In an alternate embodiment, without coiled conductors 420, the embodiment would provide an electrically inactive fixation because silicone rods 410 would not provide an electrical connection between the power source and fixation helix 140. In this inactive embodiment, a wire connector (not shown) is inserted inside lead body 120 to electrically connect the cardiac stimulating or sensing device to the cardiac tissue.
FIG. 5 shows a sectional view of a third embodiment of a compliant fixation device 500 of the present invention. A lead body 510 having a distal end 520 is shown. A fixation helix 530 is attached to distal end 520. Fixation helix 530 has a first end 540 and a second end 545. Second end 545 is sharpened to facilitate implantation of fixation helix 530 in a patient's cardiac tissue. In this embodiment, a piston 550 is shown disposed inside lead body 510. Piston 550 translates up and down inside lead body 510 so that fixation helix 530 can be retracted inside lead body 510 during insertion of the lead into the heart cavity. Translation of piston 550 is approximately 2 mm, the typical length of fixation helix 530. Piston 550 has a slot 555 formed therein. A stylet 565 is inserted into slot 555 to deploy fixation helix 530 for implantation into the cardiac tissue. Several methods of implantation will be discussed in further detail below.
The embodiment shown in FIG. 5 uses a ball and socket type connector. Piston 550 forms a socket 560 at its lower end 570. Piston 550 is preferably made from silicone. A ball 580, formed on first end 540 of fixation helix 530, is inserted into socket 560. In one embodiment, ball 580 is encapsulated, for example, in hydrogel for implantation. The hydrogel material is a biocompatible, bioreactive material that is used to fill a gap 590 between ball 580 and socket 560. The hydrogel prevents the ball from rotating during implantation so that torque can be effectively transferred to fixation helix 530 to screw it into the cardiac tissue. A material such as mannitol, described above, could also be used to encapsulate ball 580.
Ball 580 has a groove (not shown) formed therein to mesh with the screwdriver tip of stylet 565. To implant the helix, stylet 565 is inserted into slot 555. As stylet 565 is rotated, piston 550 and ball 580 also rotate simultaneously. Fixation helix 530 is thereby screwed into a patient's cardiac tissue. In an alternate embodiment, there is no hydrogel or other material in gap 590. Thus, ball 580 is allowed to rotate with respect to piston 550. In this embodiment, stylet 565 is used to turn only ball 580 to implant fixation helix 530. In either embodiment, stylet 565 can be reintroduced into slot 555 to unscrew fixation helix 530 for explantation.
After implantation of the lead described above in the first embodiment, the hydrogel or mannitol dissolves, thereby allowing ball 580 to rotate with respect to socket 560. A rotation of, for example, approximately 15 degrees in any direction can be achieved. This flexible design allows lead movement to be absorbed by the ball and socket configuration and not directly transferred to fixation helix 530. Because the embodiment shown in FIG. 5 provides electrically inactive fixation, an annular electrode 595 is disposed at distal end 520 of lead body 510. Electrode 595 is electrically connected to a cardiac stimulating or sensing device via a wire conductor (not shown).
Referring now to FIGS. 6 and 7, fourth and fifth embodiments of compliant fixation devices 600 and 700 of the present invention are shown. FIGS. 6 and 7 each show a lead body 610 having a distal end 620. A fixation helix 630 is disposed at distal end 620. Fixation helix 630 has a sharpened end 635 to facilitate implantation of the helix into a patient's cardiac tissue. Lead body 610 houses a piston chamber 640. Piston chamber 640 translates up and down within lead body 610 so that fixation helix 630 can be retracted inside lead body 610 during insertion of the lead in the heart cavity. Translation of piston chamber 640 is approximately 2 mm, the typical length of fixation helix 630.
In both embodiments, piston chamber 640 is filled with a flexible, biocompatible material 650 such as silicone rubber. Alternatively, piston chamber 640 may be filled with a biocompatible, bioreactive material, such as mannitol or PEG, so that fixation helix 630 is rigidly attached to distal end 620 of lead body 610 during insertion of the fixation helix into the patient's cardiac tissue. Once inserted, the material within piston chamber 640 dissolves, thereby allowing fixation helix 630 to freely rotate within piston chamber 640. This rotation absorbs forces from movement of lead 100 and prevents inflammation and harm to the patient's cardiac tissue surrounding the fixation helix.
Material 650 in piston chamber 640 may also be embedded with a steroid, so that as material 650 dissolves, the steroid is gradually administered to the cardiac tissue adjacent distal end 620. Application of the steroid to the cardiac tissue will prevent inflammation from occurring and will also prevent fibrous growth from occurring in the cardiac tissue surrounding fixation helix 630.
The embodiment shown in FIG. 6 has a head 660 disposed at a first end 670 of fixation helix 640. The embodiment shown in FIG. 7 has a ball 710 disposed at first end 670 of fixation helix 640. Head 660 and ball 710 are both embedded in flexible material 650, respectively, so that fixation helix 640 is flexibly attached to distal end 620 of lead body 610. Thus, forces applied to the patient's cardiac tissue by movement of the lead will be minimized.
In both embodiments, piston 650 has a slot 655 formed therein. During implantation or explantation, a stylet 665 is inserted into slot 655 such that the screwdriver tip of stylet 665 meshes with a groove (not shown) on head 660 or ball 710. Thus, as stylet 665 is rotated, piston 650 and head 660 or ball 710 also rotate. Torque is thereby effectively transferred to screw fixation helix 630 into the cardiac tissue.
Because the embodiments show in FIGS. 6 and 7 provide electrically inactive fixation, an annular electrode 680 is disposed at distal end 620 of lead body 610. Electrode 680 is electrically connected to a cardiac stimulating or sensing device via lead body 610.
Referring now to FIG. 8, a sixth embodiment of a compliant fixation device 800 of the present invention is shown. FIG. 8 shows lead body 810 having a distal end 820. A fixation helix 830 is disposed at distal end 820. Fixation helix 820 has a sharpened end 835 to facilitate implantation of the helix in a patient's cardiac tissue. Lead body 810 houses a piston 840. Fixation helix 830 has a head 850 rigidly attached at a first end 860 thereof. A first thin, flattened portion 870 is shown on first end 860. As shown in FIG. 8A, first thin, flattened portion 870 flexibly bends in the transverse direction (i.e., perpendicular to the plane of the drawing sheet). A second thin, flattened portion 880 is shown on first end 860. Second thin, flattened portion 880 flexibly bends in the lateral direction (i.e., parallel to the plane of the drawing sheet). Any forces on a patient's cardiac tissue due to movement of lead body 810 are thereby minimized by the flexible connection between head 850 and fixation helix 830.
Piston 850 has a slot 855 formed therein. During implantation or explantation of fixation helix 830, a stylet 865 is inserted into slot 855. A groove (not shown) on head 850 meshes with the screwdriver tip of stylet 865 such that rotation of stylet 865 causes piston 840 and head 850 to rotate accordingly. Thus, torque from the rotation of stylet 865 is effectively transferred to implant or extract fixation helix 830 into or out of a patient's cardiac tissue.
Fixation helix 830 may be made from a flexible polymer to provide electrically inactive fixation. In the case of electrically inactive fixation, an electrode (not shown) is added to distal end 820 of lead body 810 as described above with respect to FIGS. 5-7. Alternatively, fixation helix 830 may be made from a flexible polymer with a smaller diameter core of metal in the region of flexure to provide increased flexibility and electrically active fixation.
FIG. 9 shows a sectional view of a compliant fixation device 900 of the present invention. A lead body 910 has a distal end 920. A fixation helix 930 is disposed at distal end 920. Fixation helix 930 also translates within lead body 910 so that during implantation of the lead, fixation helix 930 can be retracted. Fixation helix 930 has a first end 940 and a second end 950. First end 940 is fixedly attached to a first annular member or ring 960. A second annular member or ring 970 is linked with first annular member 960. Second annular member 970 is also rigidly attached to a slotted end 980. Slotted end 980 is u-shaped and is configured to receive a screwdriver stylet 985. A conductor coil 990 is fixedly attached to slotted end 980 and is shown surrounding stylet 985. Conductor coil 990 provides an electrical connection between a cardiac stimulating or sensing device and fixation helix 930 to provide electrically active fixation. In this embodiment, the configuration of slotted end 980 and first and second annular members 960, 980 combine to form a universal joint.
To implant lead body 910, stylet 985 is inserted inside conductor coil 990 so that the tip of stylet 985 meshes with slotted end 980. A user then turns stylet 985 to transfer torque to slotted end 980. While annular members 960 and 970 remain within lead body 910, their movement is restricted such that torque can be efficiently transferred to fixation helix 930. This allows the user to gradually rotate fixation helix 930 to insert the helix into cardiac tissue. As fixation helix 930 is being rotated, it is also being forced outside of lead body 910. Once fixation helix 930 is fully implanted, annular members 960 and 970 will emerge from lead body 910. Without the constraints of lead body 910, annular members 960 and 970 can freely swivel about one another to provide a flexible connection between fixation helix 930 and distal end 920. Thus, movements of the patient will not be directly transferred to fixation helix 930. A stop 995 is fixedly secured to distal end 920 of lead body 910. Stop 995 prevents slotted end 980 from sliding out of lead body 910.
Fixation helix 930 is designed to provide an electrically active fixation because conductor coil 990 electrically connects fixation helix 930 to a cardiac stimulation or sensing device. Thus, one or more conductors, such as a small, flexible conductor 965, shown schematically in FIG. 9, can be attached to both annular members 960 and 970 to provide electrical continuity across the universal joint.
In an alternate embodiment, fixation helix 930 may also be designed to provide electrically inactive fixation. A separate wire connector (not shown) is inserted into lead body 910. The wire connector is connected to an electrode (not shown) at distal end 920, similar to the electrodes described above with respect to FIGS. 5-8.
Additional features may be added to any of the foregoing embodiments. For example, a fixation helix may be made from a biocompatible, porous material to enhance the sensing characteristics of the lead. In any of the embodiments, a lead may have a steroid emitted from one end to decrease the occurrence of fibroid formation. In the case of an electrically inactive fixation helix, as shown in FIGS. 6 and 7, the fixation helix may be made out of a polymer to enhance the flexibility of the distal end of the lead body. In the case of an electrically active fixation helix, the fixation helix may be made from a polymer, where the polymer surrounds a thin metal conductor. Thus, the fixation helix could be electrically connected to the cardiac stimulation device and also achieve an added degree of flexibility.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
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Intracardiac lead for compliant fixation of a distal end of the lead to cardiac tissue. A fixation helix is disposed at the distal end of the lead. The fixation helix has a first end rigidly attached to the compliant fixation device and a second end that is sharpened to facilitate insertion of the fixation helix into cardiac tissue. The fixation helix can be designed to provide for either electrically active or inactive fixation. Once the lead is implanted in the cardiac tissue, the compliant fixation device, connecting the lead with the fixation helix, reduces the amount of lead movement that is transferred to the patient's tissue at the site of implantation of the fixation helix and reduces those forces from lead movement that could cause dislodgment of the fixation helix. The compliant fixation device thereby decreases the amount of irritation to the cardiac tissue, lessens the possibility of fibrous tissue growth around the area of the fixation helix, decreases the chance of dislodgment of the fixation helix, and reduces the possibility of perforation of the cardiac wall or tamponade of the pericardial sac.
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FIELD OF THE INVENTION
[0001] The present invention relates to menstrual absorbent articles, such as female sanitary napkins which are designed to be worn in and attached to a thong slips or G-string undergarment. In general absorbent articles for wearing with and attached to an undergarment should be designed to follow the shape of the undergarment where they are attached. For a thong slip this results in a sanitary napkin or panty liner having a wider front end and a narrower rear end. This design can also be described as triangular shape or trapezoidal shape. According to the present invention such thong shaped menstrual absorbent articles are provided in a construction in which the kind and amount of material, in particular for the absorbent core, and constuction of the article, is selected such that the flexure resistance of the article remains below a critical value. In conjunction with the intimate wearing conditions achieved by the use of a thong slip this results in fitting of the sanitary napkin of the present invention in a very close proxinity to the wearer body contour providing for ‘absorption at source’ and little, if any space for liquid to escape. Articles constructed according to the present invention will display an absorbent and leakage performance in use, which surpasses even articles with a substantially higher amount of absorbent material.
BACKGROUND OF THE INVENTION
[0002] In constructing sanitary napkins several considerations have generally been accepted. For example napkins for wearing with and attached to an undergarment should be designed to follow the shape of the undergarment where they are attached. This causes considerable manufacturing complexity since a strait sided napkin is much easier to make and hence less costly. However shaped sanitary napkins or panty liners have prevailed commercially due to their technical benefit of better fit to the undergarment and wearer. Recently a new undergarment style, thong slips or G-string undergarments have achieved increased in popularity and have raised the demand for respectively designed thong sanitary napkins and panty liners. Examples of such designs can be found in WO-A-97.39.713 (to Darby), WO-A-00.30.585 (to Drevik), or DE-A-295.13.548 (to Aurisch). Commercial products include e.g. Libresse String Sanitary Napkins™ of SCA Hygiene Products of Sweden.
[0003] Another generally accepted desire for sanitary napkins or panty liners is that they shall be flexible and pliable for comfort by following the undergarment when the wearer moves. Improved flexibility was also considered to enhance the performance of absorbent articles since this would allow them to come closer to the vaginal orifice, i.e. the liquid source. This is e.g. described in EP-A-0.336.578 (to Osborn), EP-A-0.705.585 (to Querqui), EP-A-0.705.586 (to Querqui), or EP-A-0.705.584 (to Hirsch). On the other hand a limitation to flexibility was also realized already by Querqui and Hirsch and discussed already in U.S. Pat. No. 4,217,901 (to Bradstreet).
[0004] However it has been considered that both these design/construction desires competed with the fundamental and functional need that the absorbent capacity of the article is sufficient to acquire and hold all the liquid emanating from the vaginal orifice. Napkins with the conventional dog-bone or hour glass shape have a center region where highest absorbency is needed. This center region has e.g. been provided with additional absorbent material relative to the front and rear regions. Alternative designs included liquid transport constructions where the capacity outside the central area would also provide storage capacity for absorbed liquid by transport of the liquid inside a distribution layer within the absorbent core construction. Both attempts were successful and modern sanitary napkins often have an increased capacity in the central region and utilize transport construction elements for more efficient usage of the absorbent capacity outside the center. Similarly, in order to handle the differing flow quantities of menstrual liquid, sanitary napkins with higher amounts of absorbent material are available under labels such as “night”, “super” or “extra” absorbent napkins.
[0005] However most articles still have not achieved the desired balance of absorbent capacity and flexibility/liability in articles of conventional shape. For the new thong shape design no model of how to balance the absorbency, capacity, and comfort has been found hereto forth. The commercially available Libresse T mentioned above addresses this balance in favor of absorbent capacity. Since in the hierarchy of needs functional requirements (i.e. sufficient absorbent capacity to prevent leakage during use) dominate the non-functional desires (i.e. comfort, aesthetic appearance) the Libresse™ string sanitary napkin is provided with a high capacity absorbent core using flash dried cellulose compounds. This in turn creates in the product a high degree of flexure resistance, causing potentially discomfort to the wearer. However in addition to this non-functional drawback an additional functional issue arises due to the stiffness the leakage prevention performance of these articles is not optimal. It is speculated that this results from gaps and misfits due to lack of intimate molding of the article to the user.
[0006] According to the present invention menstrual absorbent articles are provided with an absorbent structure, sandwiched between a liquid permeable topsheet and a liquid impermeable backsheet having a flexure resistance and pliability, which allows the articles to follow the natural shape and fit a thong undergarment will provide if worn without any absorbent article, namely intimately molded to the body of the wearer, in particular in the region of the vaginal orifice and the crease of the buttocks. This addresses the issues with existing products regarding comfort and at the same time solves the dilemma between a too low absorbent capacity and the need for reduced flexure resistance by a low material usage.
SUMMARY OF THE INVENTION
[0007] According to the present invention menstrual absorbent articles are provided with an absorbent core or structure, conventionally sandwiched between a liquid permeable topsheet and a liquid impermeable backsheet having a flexure resistance and pliability, as measured in accordance with a modified circular bend procedure defined below, in the range of 600 grams or less, preferably 550 grams to 200 grams, more preferably 500 grams to 300 grams, most preferably between 500 grams and 450 grams. The absorbent core is the structure within the napkins according to the present invention providing the main part of the flexure resistance. In order to limit the flexure resistance added to the flexure resistance of the absorbent core the ratio between the value of flexure resistance of the absorbent core to the value of the flexure resistance of the whole absorbent napkin is above 0.5, preferably above 0.55, more preferably above 0.6, and most preferably above 0.65.
[0008] In preferred embodiments of the present invention wings or side flaps for wrapping the side edges of the crotch portion of the undergarment, especially the narrow thong portion of the undergarment, are provided by portions of the topsheet and the backsheet extending beyond the periphery of the absorbent core. Such flaps are preferably provided with attachment means and in particular preferred embodiments they extend all the way to the rearward end of the menstrual article. Finally for masking of the article as such, but at least of the side flaps, but also for masking of components of the absorbent core, for masking of the liquid absorbed into the article, or for masking of residue liquid remaining on the topsheet side of the article coloration of the article or parts or portions of the article is particularly preferred. Especially dark coloration, such as black, dark red, dark green, or dark blue is also in line with fashion aspects of currently frequently used thong undergarments.
BRIEF DESCRIPTION OF THE DRAWING
[0009] [0009]FIG. 1. Is a plan view of a preferred absorbent article of the present invention with side flaps.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] As used herein, the term “longitudinal” refers to the direction of the central longitudinal axis referred to by reference numeral 1 in FIG. 1. As used herein the term “transverse” refers to the direction of the transverse axis referred to by reference numeral 2 in FIG. 1 and which is generally perpendicular to the central longitudinal axis.
[0011] As used herein, the term “non folded configuration” or “unfolded configuration” refers to the configuration in which the side flaps of the absorbent article are spread out in the same plane as the absorbent article as illustrated in FIG. 1.
[0012] The preferred embodiment of the absorbent article of the present invention is shown in FIG. 1. The absorbent article in FIG. 1 is generally referred to by reference numeral 10 . Absorbent article 10 comprises a central absorbent pad, which is generally referred to by reference numeral 12 . The central absorbent pad 12 has longitudinal edges 13 generally oriented parallel to the central longitudinal axis 1 , transverse ends 14 generally oriented parallel to the transverse axis 2 , a body facing side 22 and an undergarment facing side. Extending from each longitudinal edge 13 of the central absorbent pad 12 are flaps 30 .
[0013] The central absorbent pad 12 usually will comprise a liquid pervious topsheet, an absorbent core 16 , and a liquid impervious backsheet. However other configurations and designs in which the topsheet or the backsheet or both are integral parts of the absorbent core, are simply not provided or wherein the absorbent core is an integral part of another element of the article are also considered useful in the context of the present invention. The central absorbent pad 12 and the absorbent core have a generally thong, trapezoidal or triangular shape having a wider front than rear portion which is especially shaped for use in modern undergarments of the G-string or string tanga type. This shape is referred to as thong shape both for describing undergarments or napkins in accordance with the present invention.
[0014] The liquid pervious topsheet, if present should be compliant, soft feeling and non-irritating to the user's skin. It can be made from any of the conventional materials for this type of use. Examples of suitable materials are woven and non-woven polyester, polypropylene, nylon and apertured films, preferably 3 dimensionally apertured films. The outer surface of the topsheet, preferably around the locations of intended liquid penetration may be treated with a compound, which renders the surface more hydrophilic allowing the liquid to penetrate the topsheet easily. Alternatively the outer surface of the topsheet, preferably between the locations of liquid penetration, may be treated with a compound which renders the surface more hydrophobic allowing liquid deposited there to migrate fast to locations where it can penetrate the topsheet easily, thus reducing liquid build up on the topsheet. The inner surface of the top sheet may be secured to the surface of the absorbent core 16 for example by the use of an adhesive or by other bonding means such as compression and/or thermo-bonding. This contacting relationship also results in liquid penetrating the topsheet easier.
[0015] The absorbent core 16 , shown in its outline by a dashed line, is positioned between the topsheet and the backsheet and comprises a fluid absorbing material. Fluid absorbing materials may be natural or synthetic or combinations thereof. Examples of absorbent materials include cellulose fibers and super-absorbent gelling materials. Absorbent materials may be used either alone or in combination with other materials, both absorbent or not. The absorbent core can be provided as a single entity or comprise several layers.
[0016] The backsheet if present is impervious to liquids or retarding liquid penetration sufficient for the intended purpose of preventing fluid from the absorbent core migrating easily towards an underlying garment and soiling the garment or body of the user. The backsheet can be made from any of the conventional materials for this type of use. Suitable materials include embossed or non-embossed polyethylene, polypropylene, or other thermoplastic films or non-wovens. Especially breathable materials or multiple layer composites are preferred for use in the sanitary napkins according to the present invention.
[0017] For constructing sanitary napkins according to the present invention it is preferred that the topsheet and the backsheet extend beyond the periphery of the absorbent core and are attached to each other in the peripheral region around the absorbent core. Particularly beneficial is the crimping, indicated by hatched lines in FIG. 1, in the front and rear peripheral region, while in the peripheral region around the absorbent core adjacent the side flaps the attachment is achieved by adhesive combination. The peripheral region around the absorbent core, if present for joining the topsheet to the backsheet, in accordance with the present invention is part of the central absorbent pad ( 12 ). Beyond the central absorbent pad only side flaps for folding around the edge of the undergarment are optionally present. Depending on the detailed construction of the optional side flaps this folding can include the peripheral region formed by the topsheet and the backsheet.
[0018] Also preferably a portion of the undergarment facing side of the backsheet is coated with a panty-fastening adhesive. The adhesive is intended to fix the central absorbent pad to the crotch of the undergarment during use of the article. Any adhesive used in the art for such purpose can be used herein, with pressure sensitive adhesives being preferred. Before the sanitary napkin is placed in a thong undergarment the adhesive should be covered by a removable release liner to prevent the adhesive from drying out, being contaminated, or sticking to a surface other than those intended for that purpose. Silicone coated paper strips or polymeric filmstrips can provide such removable release liners. In particular preferred embodiments the release liner material also provides an individual wrapping of the thong sanitary napkin.
[0019] Preferred sanitary napkins according to the present invention further comprise flaps ( 30 ) which are folded about the edge of the undergarment's leg openings in order to provide additional protection from soiling the undergarment and, provided the flaps are equipped with an attachment means such as the panty fastening adhesive mentioned above or a mechanical attachment means on their garment facing surface, to support fixation of the article to the undergarment during use. The flaps ( 30 ) can be made of any suitable material. They can be integral extensions of one, some or all of the materials used to provide the central absorbent pad ( 12 ). Alternatively the flaps ( 30 ) can be constructed separately from the absorbent central pad ( 12 ). In this case they can be made from the same materials used already for the absorbent pad or form different materials such as those mentioned herein already. If provided separately the flaps are attached to the central absorbent pad ( 12 ) by any means conventionally used in combining absorbent articles, such as adhesives, thermo, or mechanical bonding. A key benefit of the integral construction is the ease of manufacture while the attached flaps provide benefits in material consumption and flexibility in material selection for the article manufacturer.
[0020] In an embodiment according to the present invention the flaps ( 30 ) comprise a flap topsheet and a flap backsheet. In a preferred embodiment the flap topsheet is integral with the topsheet. In another preferred embodiment the flap backsheet is also integral with the backsheet. In a preferred embodiment for use as a thong shaped sanitary napkin no absorbent material or only a very thin absorbent layer such as a tissue is provided as absorbent material in the flaps.
[0021] Flaps ( 30 ) can be essentially of any shape. As illustrated in FIG. 1 the flaps ( 30 ) may have the same shape but they can also be provided asymmetrically with respect to the longitudinal axis ( 1 ) such that they do not overlap when folded in use. The flaps may have a different shape to achieve this purpose. Any differing shapes between the flaps may be used to ensure they do not overlap when folded around the thong undergarment. Of course flaps ( 30 ) can be identical in shape as shown in FIG. 1. The flaps ( 30 ) can extend along a small or a long portion of the central absorbent pad ( 12 ). It is preferred that the flaps be as long as practical so as to maximize the extent of undergarment side edge which is covered. In this respect it is possible and preferred that both flaps ( 30 ) extend all the way to the rear end of the absorbent article.
[0022] Especially string shaped undergarments and with them thong shaped sanitary napkins and panty liners have recently become fashionable in non-white coloring. It is therefore within the scope of the present invention to provide such napkins or panty liners with features suitable for the aesthetic, cosmetic and discretion/masking aspects triggering the use of string undergarments such as general fashion colors besides white, especially black, dark red, dark green or dark blue for all or some part of the article. In particular providing articles at least with flaps, which are colored so as to maintain the visual discretion achieved by the use of a thong napkin in a thong undergarment, by providing them in a color matching the color of the undergarment, is an especially appreciated article configuration. In another aspect to coloration the masking of the absorbent core—when it is unsoiled or soiled—but also of any residue liquid remaining on the topsheet by use of dark coloration of the topsheet and backsheet provides a visual benefit to the articles according to the present invention. In another aspect to ensure that the flaps are not visible during use they can be provided in a transparent or translucent design such replicating the color of the underlying material.
[0023] Flexure Resistance
[0024] A key aspect of the sanitary napkins according to the present invention is their flexure resistance behavior. Flexure resistance is a measurement which allows to quantify considerations of pliability, flexibility or stiffness, ‘Schmiegsamkeit’, and capability to follow and resemble the surface contour or topography of another structure.
[0025] The absorbent core provides the main component of the value of flexure resistance of the sanitary napkin. It is therefore essential that the absorbent core does not create a barrier to comfort and functionality of the thong sanitary napkin by having too high a flexure resistance. However the other materials and the construction of an absorbent article in general will increase flexure resistance as well. In particular the conventional layered construction of topsheet, core and backsheet, potentially with multiple layers in each of these components, where the layers are attached across their surface will increase flexure resistance. The skilled practitioner will understand that there is a positive correlation between the material quantity used in such constructions and the flexure resistance. Hence one way of influencing the flexure resistance is inclusion or removal of material.
[0026] But also the joining of the layers has a substantial effect on the flexure resistance of the final article. The lowest effect is to be expected by pure frictional attachment when the layers are simply laid on top of each other. Obviously functional criteria, e.g. that the napkin must remain unified during all use conditions, will not allow such a frictional construction: Therefore at least a minimum of attachment between the layers is needed. This can be provided by yet additional material such as adhesive, or by mechanical entanglement such as crimping, or by thermal attachment such as welding or ultrasonic bonding. Also the amount of surface involved in the attachment has an influence in on the flexure resistance. E.g. creating a peripheral region attachment allows the layers between the peripheral region to slide over each other, while the same amount of attachment surface between layers but distributed over the whole surface will result in a substantially higher flexure resistance.
[0027] Naturally other aspects than flexure resistance need to be taken into account when constructing an article, such as stability of the construction (the article must remain intact at least during use), aesthetics of the attachment (e.g. hatched crimping or flower pattern crimping), cost of material and availability of processing facilities. Taking all this into account it has been found that the flexure resistance of the article as a whole needs to be limited to 600 or less gram but also above 200 g, preferably above 300 g, more preferably above 450 g. In order to ensure that the other items besides the absorbent core increasing the flexure resistance are not over representing flexure resistance the ration of the value of flexure resistance of the core to flexure resistance of the whole napkin preferably has to be more than 0.5.
[0028] With the absorbent core being the dominating flexure resistance aspect the absorbent capacity is limited by the amount of material. Hence the performance of such articles would be expected to suffer, which however is not the case as will be shown below. In order to allow the maximum capacity to be provided, it is particularly beneficial if the absorbent core is provided with a pre-scoring in order to reduce its flexure resistance. Such pre-scoring is preferably parallel to and along its longitudinal centerline such that the garment facing surface of the absorbent core on the right and left side of the longitudinal centerline more readily fold towards each other. Scoring can be on the garment facing side or on the wearer facing side of the absorbent core. Preferred are longitudinally symmetrical scoring lines offset from the longitudinal centerline, especially in the center and front half of the thong sanitary napkin. In addition transverse scoring can also be provided to further increase flexure resistance.
[0029] Naturally any modification conventional in the art to the components or materials or construction of the absorbent articles according to the present invention, provided the inventive aspect of the low flexure resistance as included in the appended claims are preserved, will be at the discretion of the skilled practitioner and will not deviate from the present invention.
[0030] Measurement Method for Flexure Resistance:
[0031] This method is identical to the modified circular bend test procedure according to patent EP 336578. The sanitary napkin of the present invention has a low flexure-resistance. Thus, the sanitary napkin of the present invention is highly flexible and conforms very well to the various shapes of the female urogenital region. The sanitary napkin of the present invention has a flexure-resistance of less than 6.0 grams.
[0032] The flexure-resistance of a sanitary napkin is measured by peak bending stiffness. Peak bending stiffness is determined by a test which is modeled after the ASTM D 4032-82 CIRCULAR BEND PROCEDURE, the procedure being considerably modified and performed as follows. The CIRCULAR BEND PROCEDURE is a simultaneous multi-directional deformation of a material in which one face of a specimen becomes concave and the other face becomes convex. The CIRCULAR BEND PROCEDURE gives a force value related to flexure-resistance, simultaneously averaging stiffness in all directions.
[0033] Apparatus:
[0034] The apparatus necessary for the CIRCULAR BEND PROCEDURE is a modified Circular Bend Stiffness Tester, having the following parts:
[0035] A smooth-polished steel plate platform which is 102.0×102.0×6.35 millimeters having an 18.75 millimeter diameter orifice. The lap edge of the orifice should be at a 45 degree angle to a depth of 4.75 millimeters.
[0036] A plunger having an overall length of 72.2 millimeters, a diameter of 6.25 millimeters, a ball nose having a radius of 2.97 millimeters and a needle-point extending 0.88 millimeter therefrom having a 0.33 millimeter base diameter and a point having a radius of less than 0.5 millimeter, the plunger being mounted concentric with the orifice and having equal clearance on all sides. Note that the needle-point is merely to prevent lateral movement of the test specimen during testing. Therefore, if the needle-point significantly adversely affects the test specimen (for example, punctures an inflatable structure), than the needle-point should not be used. The bottom of the plunger should be set well above the top of the orifice plate. From this position, the downward stroke of the ball nose is to the exact bottom of the plate orifice.
[0037] A force-measurement gauge and more specifically an Instron inverted compression load cell. The load cell has a load range of from 0.0 to 1000 grams. Of course force measurements are not identical to mass measurements. However, the gauge is set such that it displays a value of mass excerting the equivalent force under gravity.
[0038] An actuator, and more specifically the Instron Model No. 6021 having an inverted compression load cell. The Instron 6021 is made by the Instron Engineering Corporation, Canton, Mass.
[0039] Number and Preparation of Specimens
[0040] In order to perform the procedure for this test, as explained below, five representative sanitary napkins are necessary. From one of the five napkins to be tested, some number “Y” of 37.5×37.5 millimeter test specimens are cut. Specimens should be representative of the center of the napkin, or the region of highest apparent stiffness and not include portions in which e.g. a topsheet is joined directly to a backsheet. The reason that these specimens are not tested is due to the realization that prior art napkins exist in which a topsheet is joined to a barrier sheet beyond the edges of an absorbent core in the periphery of the napkin, such portions of which are highly flexible. However, the present invention is concerned with the overall flexibility of the sanitary napkin and not merely the peripheral portions thereof and, therefore, the flexibility of the present invention is more concerned with the flexibility of the significant absorbent portions of the sanitary napkin. If any of these significant absorbent portions of the sanitary napkin meet the parameters of this test, then the sanitary napkin satisfies the test. Therefore, a number of different specimens should be tested from each sanitary napkin. For the purpose of the present invention, the structurally least flexible portion of the sanitary napkin should be tested. The test specimens should not be folded or bent by the test person, and the handling of specimens must be kept to a minimum and to the edges to avoid affecting flexural-resistance properties. From the four remaining sanitary napkins, an equal number “Y” of 37.5×37.5 millimeter specimens, identical to the specimens cut from the first napkin, are cut. Thus, the test person should have “Y” number of sets of five identical specimens.
[0041] The same sample preparation is done for the absorbent core, prior to installation of such core material into the sanitary napkin. Alternatively, or in order to evaluate existing sanitary napkins the absorbent core should be carefully removed between the topsheet and the backsheet.
[0042] Procedure
[0043] The procedure for the CIRCULAR BEND PROCEDURE is as follows. The specimens are conditioned by leaving them in a room that is 21+/−1 DEG C and 50+/−2% relative humidity for a period of two hours. The test plate is leveled. The plunger speed is set at 50.0 centimeters per minute per full stroke length. A specimen is centered on the orifice platform below the plunger such that the body surface of the specimen is facing the plunger and the garment surface of the specimen is facing the platform. The indicator zero is checked and adjusted, if necessary. The plunger is actuated. Touching the specimen during the testing should be avoided. The maximum force reading to the nearest gram is recorded. The above steps are repeated until all five of the identical specimens have been tested.
[0044] Calculations
[0045] The peak bending stiffness for each specimen is the maximum force reading for that specimen. Remember that “Y” number of sets of five identical specimens were cut. Each set of five identical specimens is tested and the five values received for that set are averaged. Thus, the test person now has an average value for each of the “Y” sets tested. Remember, if any of the significantly absorbent portions of the sanitary napkin have the requisite flexure-resistance, then the napkin satisfies the parameters of this test. Therefore, the flexure-resistance for a particularly designed sanitary napkin is the greatest of these average peak-bending stiffness.
[0046] Experimental Core Napkin Flexure Resistance Data Comparison
[0047] The following results were obtained with the above mentioned modified circular bend test procedure. The results are in grams. The products tested are:
[0048] a commercially available thong product, Libresse™ String Sanitary Napkins with side flaps
[0049] a commercially available sanitary napkin with side flaps for heavy loading conditions, Always™ Night Ultra, available from The Procter and Gamble Company, e.g. in Germany
[0050] 4 experimental thong sanitary test napkins. All 4 were in the shape as shown in FIG. 1, The topsheet was the same as in the commercially available Always™ product, an apertured formed film, available from The Procter & Gamble Company under the trade name Dryweave. The backsheet was the same polyethylene film as used in the commercially available Always™, having a thickness of 20 micrometer. Both the topsheet and the backsheet extended beyond the absorbent core as shown in FIG. 1 forming side flaps for folding around the edge of the thong undergarment. The backsheet was provided with pressure sensitive adhesive in 3 regions, one each in the side flaps and one in the central region. The adhesive was the same as that on the commercially available Always™. The construction of the thong test napkins further included a fine, low basis weight web of adhesive between the topsheet and the absorbent core and between the core and the backsheet. A peripheral region around the thong test napkins was also provided to encase the absorbent core. The absorbent core in all of the products was provided by a MBAL core construction. MBAL is a fibrous material comprising cellulose fibers and bi-component (polypropylene shaft with ethylene coated on the outside) thermo-bondable fibers. In this fiber matrix super-absorbent particles are dispersed homogeneously. The MBAL material is available in different basis weights, where primarily the quantity of super-absorbent particles per square area changes and with it the absorbent capacity of the structure. The MBAL material is unified by use of thermal bonding and latex bonding on its surface. In 2 of the 4 thong test napkins 5 creasing lines were introduced running in longitudinal direction, substantially parallel and symmetrically to the longitudinal centerline. Also in 2 each, of the 4 thong test napkins different absorbent core capacities by use of different basis weights were used.
TABLE 1 Thong Thong test napkin Thong test napkin Libress test with MBAL Thong with MBAL String Always napkin 300 g/m 2 + test napkin 180 g/m 2 + Sanitary Night with MBAL 5 length with MBAL 5 length Product Napkins Ultra 300 g/m 2 wise flex lines 180 g/m 2 wise flex lines Super- 0 118 105 105 31 31 absorbent particle basis weight (g/m 2 ) *Dunk 36 40 46 46 28 28 Capacity (g absorbed/g- dry-weight) Flexure **Not 357 g 846 g 489 g 520 g 336 g resistance measur- of the core able alone Flexure 3467 g 705 g NA 877 g NA 489 g resistance of the sanitary napkin Leakage 60 40 NA 60 NA 45 diary test ***(% changes with leakage) Flexure NA 0.507 NA 0.558 NA 0.687 resistance ratio of core to napkin
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The present invention relates to menstrual absorbent articles, such as female sanitary napkins which are designed to be worn in and attached to a thong slips or G-string undergarment. In general absorbent articles for wearing with and attached to an undergarment should be designed to follow the shape of the undergarment where they are attached. For a thong slip this results in a sanitary napkin or panty liner having a wider front end and a narrower rear end. This design can also he described as triangular shape or trapezoidal shape. According to the present invention such thong shaped menstrual absorbent articles are provided in a construction in which the kind and amount of material, in particular for the absorbent core, and construction of the article, is selected such that the flexure resistance of the article remains below a critical value. In conjunction with the intimate wearing conditions achieved by the use of a thong slip this results in fitting of the sanitary napkin of the present invention in a very close proxinity to the wearer body contour providing for ‘absorption at source’ and little, if any space for liquid to escape. Articles constructed according to the present invention will display an absorbent and leakage performance in use, which surpasses even articles with a substantially higher amount of absorbent material.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a lamp circuit and, more particularly, to a lamp circuit that supplies a voltage to a load based on a received voltage from a light-radiating module thereof.
2. Description of the Related Art
Conventional lamps generally comprise a light-radiating module which radiates light through light-radiating devices such as light-emitting diodes (LEDs), bulbs or light tubes. Since the light-radiating module generates a significant amount of heat during operations, cooling equipments such as fans or heat sinks are required for cooling the light-radiating module in order to prolong the service life of the lamp.
Apart from a load of the light-radiating module, the conventional lamps also comprise a direct current (DC) load. Generally, the DC load requires different supply voltage from the light-radiating module. Therefore, multiple supply voltages are irreversibly required in the lamps.
Referring to FIG. 1 , a conventional lamp circuit is disclosed. The lamp circuit comprises a DC power supply 91 , a driving unit 92 and a light-radiating module 93 . The DC power supply 91 is electrically connected to the driving unit 92 which, in turn, is electrically connected to the light-radiating module 93 . The DC power supply 91 generates a first voltage V 91 that is provided to the driving unit 92 . The driving unit 92 generates a constant DC current Ic that passes through the light-radiating module 93 . With the constant DC current Ic, the light luminance of the light-radiating module 93 is kept in a constant level. The light-radiating module 93 comprises a feedback end 931 electrically connected to the driving unit 92 . The light-radiating module 93 sends a feedback signal back to the driving unit 92 via the feedback end 931 such that the driving unit 92 may keep the constant DC current Ic passing through the light-radiating module 93 from varying based on the variation of the feedback signal.
A cooling fan 95 is required to be equipped in the lamp for cooling purpose as the light-radiating module 93 generates a significant amount of heat due to the constant DC current Ic passing therethrough. Since the cooling fan 95 requires different supply voltage from the light-radiating module 93 , an additional supply voltage has to be provided therefor.
Referring to FIG. 1 , the lamp circuit further comprises a voltage regulation unit 94 electrically connected to the driving unit 92 to receive a DC voltage therefrom. Alternatively, the voltage regulation unit 94 may also be electrically connected to the output ends of the DC power supply 91 to receive a first voltage V 91 . The voltage regulation unit 94 converts the first voltage V 91 into a second voltage V 92 that is provided to the cooling fan 95 .
The conventional lamp circuit has some drawbacks. For instance, the conventional lamp circuit requires the voltage regulation unit 94 for providing the second voltage V 92 to the cooling fan 95 . In this regard, circuitry complexity and costs are increased.
Therefore, it is desired to improve the conventional lamp circuit.
SUMMARY OF THE INVENTION
It is therefore the primary objective of this invention to provide a lamp circuit which simplifies the circuitry complexity and reduces the costs by avoiding extra components used.
It is another objective of this invention to provide a lamp circuit which has more functions and simplifies the circuit complexity of the feedback circuit.
It is another objective of this invention to provide a lamp circuit which requires smaller volume of a transformer by using a micro-controller unit.
The invention discloses a lamp circuit, comprising a direct current (DC) power supplier adapted to provide a supply voltage, a driving unit coupled to the DC power supplier so as to receive the supply voltage, and a light-radiating module coupled to the driving unit and having a DC output side. The driving unit generates a constant DC current that passes through the light-radiating module such that a DC voltage to be supplied to a DC load is built at the DC output side.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 shows a conventional lamp circuit.
FIG. 2 shows a lamp circuit according to a first embodiment of the invention.
FIG. 3 shows a lamp circuit according to a second embodiment of the invention.
In the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the term “first”, “second”, “third”, “fourth”, “inner”, “outer” “top”, “bottom” and similar terms are used hereinafter, it should be understood that these terms are reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 2 , a lamp circuit is disclosed according to a first embodiment of the invention. The lamp circuit comprises a DC power supply 1 , a driving unit 2 and a light-radiating module 3 . The DC power supply 1 is electrically connected to the driving unit 2 which, in turn, is electrically connected to the light-radiating module 3 . The DC power supply 1 receives an external supply voltage (not shown) and processes the received supply voltage with a series of procedures to generates a supply voltage V 1 at an output side thereof, such as voltage dropping, rectifying and voltage regulation and so on. The supply voltage V 1 is provided to the driving unit 2 . The driving unit 2 generates a constant DC current Ic that passes through the light-radiating module 3 . The constant DC current Ic is kept from varying such that the light luminance of the light-radiating module 3 is kept in a constant level.
The driving unit 2 is an independent unit which ensures the operation of the lamp circuit by separating the control loop and power loop. The driving unit 2 comprises a switching unit 21 , a transformer 22 , a rectifying and filtering element 23 and a feedback unit 24 . The switching unit 21 is connected to the DC power supply 1 . A primary side of the transformer 22 is electrically connected to the switching unit 21 and a secondary side of the transformer 22 is electrically connected to the rectifying and filtering element 23 . The rectifying and filtering element 23 has an output end electrically connected to the light-radiating module 3 .
The switching unit 21 receives the supply voltage V 1 and generates a first pulse to be received at the primary side of the transformer 22 . The transformer 22 converts the first pulse into a second pulse at the secondary side thereof. The second pulse is sent to the rectifying and filtering element 23 which, in turn, converts the second pulse into the constant DC current Ic. Note that by adjusting the turn ratio between the primary side and the secondary side, the voltage ratio and current ratio between the first pulse and the second pulse may be designed based on power consumption and power characteristic of a load (not shown).
To prevent the constant DC current Ic from varying, the light-radiating module 3 comprises a feedback end 31 electrically connected to the feedback unit 24 of the driving unit 2 . The feedback end 31 sends a feedback signal to the feedback unit 24 of the driving unit 2 . Based on the feedback signal, the driving unit 2 keeps the constant DC current Ic from varying so as to keep the light luminance of the light-radiating module 3 in a constant level.
Referring to FIG. 2 again, the light-radiating module 3 in the first embodiment of the invention comprises a plurality of light-radiating elements 32 and a DC output side 33 . The light-radiating elements 32 are connected in series, with a connection node 321 being formed between two series-connected light-radiating elements 32 . In FIG. 2 , at least one connection node 321 is formed.
The DC output side 33 of the light-radiating module 3 is electrically connected to a DC load 4 so that the DC output side 33 may provide a DC voltage V 2 to the DC load 4 . The DC load 4 may be a cooling fan or DC motor. The DC output side 33 has a first connection end 331 and a second connection end 332 . The first connection end 331 is electrically connected to ground and the second connection end 332 is electrically connected to one of the connection nodes 321 .
Specifically, since each light-radiating element 32 has an internal resistance, the DC voltage V 2 is established at a connection node 321 when the constant DC the current Ic passes through the light-radiating module 3 . Each connection node 321 has different voltage with respect to ground. The second connection end 332 of the DC output side 33 may be connected to a proper connection node 321 according to the voltage requirement of the DC load 4 . In this way, a proper voltage (i.e. DC voltage V 2 shown in FIG. 2 ) may be provided to the DC load 4 by the light-radiating module 3 through the DC output side 33 .
Referring to FIG. 3 , a lamp circuit is disclosed according to a second embodiment of the invention. In comparison with the first embodiment, a digital driving unit 5 is provided in the second embodiment. The digital driving unit 5 comprises a micro-controller unit (MCU) 51 , an electronic switch 52 , a transformer 53 and a rectifying and filtering element 54 . The MCU 51 is electrically connected to the DC power supply 1 so as to receive the supply voltage V 1 therefrom. The electronic switch 52 is electrically connected to a control end 511 of the MCU 51 such that a control signal, that is used to control the ON/OFF operation of the electronic switch 52 , may be sent to the electronic switch 52 via the control end 511 . A primary side of the transformer 53 is electrically connected to the electronic switch 52 and a secondary side of the transformer 53 is electrically connected to the rectifying and filtering element 54 . The rectifying and filtering element 54 is electrically connected to the light-radiating module 3 . A first pulse is generated at the primary side of the transformer 53 during switching operation of the electronic switch 52 . A second pulse is generated at the secondary side of the transformer 53 . The rectifying and filtering element 54 generates and outputs the constant DC current Ic to the light-radiating module 3 . The electronic switch 52 may be a transistor switch.
The MCU 51 in the second embodiment further comprises a feedback signal receiving end 512 electrically connected to the feedback end 31 of the light-radiating module 3 . Upon receipt of the feedback signal from the feedback end 31 , the MCU 51 may control the digital driving unit 5 to output the constant DC current Ic.
Specifically, the light-radiating module 3 in the second embodiment may also output the DC voltage V 2 to the DC load 4 via the DC output side 33 thereof. Since the DC load 4 and the DC output side 33 are connected in parallel, a portion of the constant DC current Ic will be shared by the DC load 4 , resulting in a variation of the feedback signal. In response thereto, the feedback signal receiving end 512 increases or reduces the magnitude of the outputted DC current thereof based on the variation of the feedback signal in order to prevent the constant DC current Ic from varying.
In comparison with the independent driving unit 2 in the first embodiment, the digital driving unit 5 has advantages such as reducing the costs as well as circuit complexity of feedback circuit. Furthermore, since the digital driving unit 5 is not operated under large currents, a small-volume transformer 53 may be used. In another embodiment, the MCU 51 in the second embodiment may comprise an additional control end electrically connected to an input end of the DC load 4 . For example, assume that the DC load 4 is a cooling fan; the MCU 51 may send a rotation speed control signal to the cooling fan via the input end of the cooling fan. In this way, the rotational speed of the cooling fan may be controlled. Based on this, by using the MCU 51 , more functions may be implemented in the lamp circuit without using complex rotation speed control circuit.
To achieve high circuit integrity, the digital driving unit 5 (or some components of the digital driving unit 5 such as the MCU 51 ) may be mounted on a circuit board in the cooling fan.
In conclusion, the invention provides the DC voltage V 2 to the DC load 4 through the light-radiating module 3 without using an extra voltage regulation unit 94 . Thus, costs are reduced and circuit complexity is simplified.
Although the invention has been described in detail with reference to its presently preferable embodiment, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.
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A lamp circuit is disclosed, comprising a direct current (DC) power supplier adapted to provide a supply voltage, a driving unit coupled to the DC power supplier so as to receive the supply voltage, and a light-radiating module coupled to the driving unit and having a DC output side. The driving unit generates a constant DC current that passes through the light-radiating module such that a DC voltage to be supplied to a DC load is built at the DC output side.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to tools for applying films to smooth surfaces, e.g. adhesive films to glass surfaces, in particular solar films for automotive windows.
2. Discussion of Relevant Art
Various types of films for covering or altering many types of surfaces have been used for many years. Wallpaper and other wallcovering materials such as self-adhesive films or films which adhere to surfaces through static electrical effects are one category. An increasing variety of films are being used to decorate or alter the light transmission properties of glass surfaces, flat and curved, residential/commercial through auto safety glazing. Some of these films are used to “darken” the glass by reducing light transmission; others affect work or living space environments by controlling heat gain and reducing solar radiation-caused fading, while other films may serve additional functions of enhancing safety and security, much as safety glass auto windshields prevent shattering. The application of any of these films can be difficult, and is a laborintensive, tedious process, which may explain why “paperhangers” are cited as ultimate examples of busy persons. Common problems include the formation of bubbles or folds in the films during application and ripping or otherwise damaging the films. The application of adhesive films poses the problem of applying them smoothly to the surface to be covered and trimming off any excess material before the adhesive sets. Application to auto glass surfaces, which can be curved convexly or concavely, even including compound curvatures, can be particularly difficult, requiring a significant amount of training for workers in this industry. When installing a film onto a concave surface, such as the inside surface of a car window, common problems reside in the fact that the technician is applying a flat film to a curved surface. The inherent tension on the film to conform to the curved surface of the glass promotes the formation of bubbles or fold-fingers in the films during application. Additionally, the technician must remain cognizant of the relative fragility of the medium and use care not to cause any ripping, creasing, scratching or other damage to the films. The application of adhesive films poses the problem of applying them smoothly to the surface to be covered and trimming off any excess material before the adhesive sets.
Squeegees, rollers and similar tools can be used in applying many of the films discussed above, but no ideal tool appears to be available. Problems persist in attaining the goal of smooth application of films to the surfaces requiring them, without involving the problems discussed above. A number of patents have been reviewed which are directed to squeegees, scrapers and the like.
Design Pat. No. 332,160 discloses a triangular squeegee with straight edges which is thicker in the middle and symmetric, the opposite sides being mirror images.
Design Pat. No. 364,719 discloses a roughly triangular cleaning tool with two rounded corners, a raised central portion and a generally flat bottom.
Other patents uncovered during the search which may also be of some interest, include the following:
Design Pat. No. 392,078 discloses an auto window scraper with a curved, narrow working edge and a symmetric profile.
Design Pat. No. 410,309 discloses a scraping tool having five edges, one of them “arcuate” (convexly curved), a raised central portion and a flat bottom.
Design Pat. No. 261,601 discloses a pan cleaner with both straight and curved edges, a raised central portion and a flat bottom.
U.S. Pat. No. 1,388,282 discloses a generally triangular cooking vessel wipe having two straight edges and one rounded edge with a thickened central portion and a symmetric cross section. The article is molded of non-porous rubber, and the thickened center is designed to provide “the degree of stiffness necessary”.
U.S. Pat. No. 2,262,316 discloses a culinary scraper with celluloid blades having curved or straight edges and a removable handle.
U.S. Pat. No. 3,821,828 discloses a putty application tool with a curved edge formed by intersecting chamfered surfaces. The material is unspecified.
U.S. Pat. No. 4,784,598 discloses a drywall tool with one curved edge and a handle on top. According to the final paragraphs of column 3, the tool is made of a resilient, flexible material selected for a particular hardness or stiffness. The operation of the tool with its tapered edge is shown in FIG. 7.
U.S. Pat. No. 4,919,604 discloses a finishing tool having an arcuate blade with a central spine and a handle. The blade has a tapered, deformable edge and is flat on the bottom. Its flex properties are described in column 3.
U.S. Pat. No. 5,475,199 discloses a heater for sealing thick plastic films, having a roughly triangular shape like a flatiron.
U.S. Pat. No. 2,261,063 discloses a conventional putty knife with a handle.
U.S. Pat. No. 2,046,599 discloses a scraper with both straight and curved edges, a symmetric cross section and an angled handle.
Although a variety of tools and devices are available for the application of films to various surfaces, in particular for the application of films to glass surfaces such as automotive windows, problems persist in successfully applying such films to curved auto windows without tearing or otherwise damaging the films or leaving bubbles, creases or other defects in the films once applied and adhered to the windows.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide tools which are effective in the smooth application of a variety of films to flat or curved surfaces without damaging the films. A particular object of the invention is tools for the application of films, especially adhesive films, to glass surfaces, particularly curved auto windows, without damaging the films or leaving any air bubbles, creases or defects in the applied films. A further object of the invention is to provide tools with arcuate edges having sufficient flexibility to apply such films while eliminating air bubbles and the like. Another object of the invention is to provide such tools which are molded of polymeric materials which are sufficiently flexible and resilient to provide a flexible edge to apply films, and soft enough to prevent tearing or abrading the films during application. A further object of the invention is to mold such tools in a bilaterally symmetric form which tapers uniformly on each surface from a thicker central portion to an edge which is sufficiently flexible to effectively apply the films discussed above. Another object of the invention is to provide molded tools having flexible arcuate edges which are blunted to avoid cutting or scratching the films during application. Still another object of the invention is to provide tools with multiple arcuate edges of different radii of curvature, suitable for a variety of uses in film application. Certain of these objects are attained by the embodiments disclosed and claimed below.
In accordance with the present invention, a tool for the application of films, especially adhesive films, is provided which has at least one arcuate edge having sufficient flexibility and resiliency and a quality of films to smooth surfaces (including those which are convexly or concavely curved) without leaving air bubbles, creases, damage to the films or other defects. The tool preferably has from two to four arcuate edges having different radii of curvature, and at least one narrow, blunted point or tip for working in close quarters. The tool can also have at least one straight edge. The desired resiliency is attained by molding the tool to taper uniformly from a central thicker portion to the arcuate edges, preferably by molding to provide two essentially identical surfaces (i.e., with bilateral symmetry), and with the arcuate edges slightly blunted to prevent cutting the films during application. The material of which the tool is molded has a degree of hardness sufficient to apply pressure smoothly and uniformly to the films, but not hard enough to tear, abrade or otherwise damage the films. Such qualities and parameters are quantified below. A preferred embodiment of the invention has three arcuate edges having at least two different radii of curvature and a generally triangular shape having a blunt end and a narrower or somewhat pointed end, tapering uniformly from a thicker central portion to the arcuate edges, which are slightly blunted.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the present invention will be further understood by perusal of the following detailed description, the appended claims, and the drawings, in which:
FIG. 1 is a plan view of an applicator of the invention having a roughly triangular form and three arcuate edges;
FIG. 2 is a side perspective view of the applicator of FIG. FIG. 3 is a side view of the applicator;
FIG. 4 is an end view of the blunt end of the applicator;
FIG. 5 is a cutaway side perspective view of the applicator showing the central profile of the item;
FIG. 5A is a detail cutaway view of the applicator edge;
FIG. 5B is a second detail drawing view of the applicator; and
FIG. 6 is a plan view of the reverse side of the applicator of FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Firstly, although the embodiment described above is bilaterally symmetric, it may be described as having upper and lower surfaces or first and second surfaces, even though these surfaces may be essentially identical. Where used, the expression “and/or” is used in the sense of A, B or A+B. The term “arcuate” is used to mean an edge or contour having a uniform radius of convex curvature.
Turning now to the drawings, FIG. 1 shows a generally triangular applicator tool 10 having a first side 12 A and a second side (not visible here) 12 B. Each side has a raised or thicker central portion 14 A (and 14 B, not visible here). Mold marks 16 A and 16 B are left on the tool by the preferred dual cavity molding process, which easily produces a tool having bilateral symmetry. Arcuate edges 18 , 20 and 22 have at least two different radii of curvature R 1 , R 2 and R 3 , respectively, as indicated in FIG. 1 . Depending upon the type of application, these radii can range from about to about inches. In some cases, convexly-curved edges of non-uniform or variable radii can be used. Optionally, the tool can be provided with at least one straight edge, shown in FIG. 6 as 22 A. From the raised central portions 14 A and 14 B, the tool tapers gradually over tapered portions 24 A, 26 A, 28 A on one side and 24 B, 26 B and 28 B on the other side (not visible here). Generally, these portions of the tool taper in a straight line as shown, but could taper in a concavely ( 26 A′, 26 B′) or convexly ( 26 A″, 26 B″) curved manner to produce desired flex properties, as illustrated in FIGS. 5A and 5B . As shown in the latter (and other) figures, the edges 18 , 20 and 22 have a finite width rather than being sharp enough to cut the film being applied. The width of the edges can be in the range of from about 0.01 to about 0.1 inch, preferably in the range of from about 0.02 about 0.1 inch, preferably in the range of from about 0.02 to about 0.08 inch, and for the application of auto window tinting films, about 0.03 inch. The edges can be relatively flat and/or rounded in contour, depending upon the intended application.
The tool is molded of a suitable polymeric material which will produce the desired flex properties of the arcuate working edges and have a degree of hardness which avoids damage to the film, as discussed above. The tool is preferably injection molded in a dual-cavity mold to provide bilateral symmetry. Since the relatively thin edges of the tool generally will not accommodate tab gates for the injection of the molten resin, the molds are gated in the center of both cavities, leaving a sprue 16 A and sprue puller 16 B on the finished tool. The arcuate edges can have a flex modulus value in the range of from about 8000 to about 220,000 psi, preferably from about 20,000 to about 180,000 psi, and most preferably from about 80,000 to about 120,000 psi, for use in applying typical darkening window films to auto windows. The different arcuate edges can have different flex values within these ranges, and values at various points within these ranges can be selected for tools to be used in applying films of differing physical properties and/or thickness, to various types or surfaces. The hardness of the molded material, based upon Shore D Hardness values, can be in the range of from about 10 to about 80, from about 30 to about 60 or from about 12 to about 20, preferably from about 14 to about 18, and most preferably from about 15 to about 17.
Tools in accordance with the invention can be designed and produced to apply a wide variety of films, including adhesive and nonadhesive types, ranging in thickness from about 0.008 to about 0.03 inches. For example, in the area of auto window films, the thickness of conventional tinting films can range from about 0.008 to about 0.03 inches, while films up to about 0.03 inches, preferably 0.024 inches, can be used to provide resistance to shattering as well as tinting.
The tools can be molded of any suitable thermoplastic or thermosetting polymer, including thermoplastic polyolefins having densities in the range of from about 0.86 to about 1.05 g/mL, such as various types of polyethylenes, polypropylenes (including copolymers comprising monomers having 2 carbons or more than three carbons) (extending to octane monomers), thermoplastic polyesters, including those based upon saturated poyester resins; polyurethanes, melt-processible rubbers and silicone polymers having similar properties. Polyolefin ketones can be included. Polybutadiene and styrene-butadiene copolymers such as the commercial Krayton(R) rubbers can be used. ABS (acrylonitrile-styrene-butadiene) polymers are also suitable, especially at low CN levels. Polyethylenes can include a variety of comonomers, comprising olefins and saturated hydrocarbons from polypropylene up to about octanes, where the use of hexane and octane comonomers added to a Ziegler catalyst in a loop reactor yield LLDPE (linear low density polyethylene) and higher density polyolefins with high elongation and ESCR (environmental stress crack resistance). Other suitable comonomers inlcude fatty acid esters such as vinyl acetate (at less than about 29 mole percent) and acrylic acid and ester derivatives such as n-butyl acrylate. Polybutene, polybutylene and butyl rubber (polyisobutylene containing small amounts of isoprene) are also suitable. Thermoplastic polymers are presently preferred due to the relative ease of injection molding with same. Plasticized thermoplastics such as polyvinyl chloride and ABS polymers can be used.
In addition to thermoplastic polymers, some thermosetting or chain extending polymers can be used. For example, polyurethanes, based upon either polyesters or polyethers, can be used. Plasticized epoxy resins and silicone rubbers can also be used. Vulcanized rubbers such as used for auto tires can be used, as well as thermoplastic vulcanates, and thermoplastic rubbers filled with pre-crosslinked rubbers. HDPE (high density polyethylene) and LDPE (low density polyethylene) can be crosslinked three-dimensionally with organic peroxides, especially if they contain butylene comonomers.
Those skilled in the molding arts and familiar with the requirements of tools for particular applications will be able to choose a variety of suitable polymeric materials for molding the tools of the invention, basing the choices upon economics as well as the required physical properties of the finished tools.
The radii of curvature of the arcuate working edges can be in the range of from about three inches to about 40 inches, preferably from about four inches to about 30 inches, and most preferably from about six inches to about 25 inches for use in the application of adhesive films to convexly-curved auto windows.
FIG. 2 shows the same features as FIG. 1 , with mold mark 16 B and the countours of raised portion 14 B on the underside shown in dotted lines. The edge 22 can be seen to have a finite width rather than a cutting edge. A narrow or almost pointed tip 30 is visible in both FIGS. 1 and 2 . This tip is useful for gaining access to narrow spaces where the film must be smoothed during application, and for holding the film in place during trimming.
FIG. 3 is a side view of tool 10 with tip 30 at the left, showing the finite widths of edges 18 and 22 as well as the relative tapering longitudinally (from edge 18 to tip 30 ) from raised central portions 12 A and 12 B to those edges. FIG. 4 is an end view from the “blunt” end (edge 18 ), again illustrating the finite width of the edges 18 , 20 and 22 and the degree of tapering in the lateral direction (between the center and longer edges 20 and 22 ).
FIG. 5 illustrates the cross section 32 of the central portion of the tool through a broken sectional view. FIGS. 5A and 5B illustrate variations on the edge shape and tapering from the central portion of the tool. In FIG. 5A , the tool tapers to edge 22 A in a concavely curved fashion ( 26 A′ and 26 B′) rather than in a linear manner, and edge 22 A is relatively flat. This type of edge tends to remove more water when used with wet films. In FIG. 5B , the tool tapers via convexly curved surfaces 26 A″ and 26 B″ to a rounded edge 22 B. While the tools presently produced employ a linear taper and slightly rounded edges, any combination of the contours discussed above can be used to provide tools having the proper flex properties and edges which will produce the desired results without damaging the films.
FIG. 6 shows the reverse side of the tool, revealing the symmetric features hidden in FIGS. 1 and 2 . Also, in FIG. 6 alone, edge 22 A is shown as straight rather than arcuate, representing the utility of having at least one straight edge in some tools. The portion of the tool labelled as mold marks 16 A and 16 B has been drilled or punched out to produce a through hole 17 , which can be used to hang the tool up for storage and/or fitted with temporary or permanent handles (not shown) to facilitate handling and use of the tool.
Various changes and modifications to the presently preferred embodiments of the invention will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. Therefore, the appended claims are intended to cover such changes and modifications, and are the sole limits on the scope of the invention.
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Film applicator tools are provided which have at least two arcuate edges which are sufficiently flexible and resilient to permit application of adhesive films to smooth surfaces without leaving air bubbles, creases or other defects. The tools are molded of polymeric materials which have hardness values effective to permit the application of smooth and uniform pressure without tearing or abrading the films.
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FIELD OF THE INVENTION
The present invention relates generally to medical electronic devices and, more particularly, to implantable devices for pacing, cardioverting or defibrillating a heart. Specifically, the present invention is directed to a lead designed to be placed into the ventricle which can pace, cardiovert or defibrillate the heart, and sense cardiac activity in the heart, in conjunction with an implanted pacemaker and/or defibrillator.
BACKGROUND OF THE INVENTION
A number of types of implantable devices are in use to monitor and control the electrical activity of the heart. For example, it is known to have an implanted pacemaker interconnected via a transvenous pacing lead to an electrode in intimate contact with the myocardial tissue of the heart. The electrode can both sense the electrical activity of the heart and deliver an electrical stimulus provided by the pacemaker when required. Other systems include pacemakers and transvenous pacing leads which have a variety of sensor electrodes proximally spaced behind the tip electrode of the pacing lead. The sensors provide information to the pacemaker. There are also systems which monitor and provide automatic defibrillation utilizing an implanted power source and an electrode system, either attached to the surface of or implanted within the heart. Still other systems combine the pacemaker function with an automatic defibrillation capability, and may include multiple leads extending to internal as well as external portions of the heart.
More specifically, it is known to have a combination pacing, cardioversion, defibrillation and sensing lead implanted into the ventricle, and a large surface area patch electrode affixed to or near the exterior surface of the heart, both of which are connected to a pacemaker and/or a defibrillator. Additional pacing systems may also include a transvenously implanted lead which provides only sensing within the atrium. With this type of system, there may be two different pacing, cardioversion, defibrillation or sensor leads extending intravenously into the interior of the heart, in addition to a patch lead and electrode affixed to or near the epicardial surface of the heart, all connected to the pacemaker and/or defibrillator.
During the implantation procedure, the attending physician may implant a combination lead having pacing and sensing electrodes, which also includes a defibrillation electrode mounted proximally of the distal tip, and then test whether the defibrillation electrode can provide sufficient energy to defibrillate the heart. In the event that defibrillation requires too much energy or cannot be accomplished by the combination lead, a second lead having a patch electrode affixed to or near the epicardial surface of the heart or nearby, such as in a subcutaneous or subcostal site may be required. If such a patch electrode is also required, following affixation of the patch electrode, the attending physician may test various bipolar combinations of the leads for defibrillating the heart, using alternatively the patch electrode and/or the electrode on the combination lead as the cathode(s) or anode(s) to determine the lowest threshold for defibrillation.
Thus, while it may be necessary to have the patch electrode affixed to or near the exterior surface of the heart (or subcutaneously or subcostally near the heart), preferably if defibrillation can occur by the use of a combination pacing and defibrillation electrode placed in the right ventricle, the necessity for opening the chest cavity and affixing the patch electrode on or near the heart may be avoided.
When utilizing a pacing lead defibrillator electrode to accomplish pacing, cardioversion or defibrillation, it is important to recognize that preserving the atrial-ventricle synchronization, by proper timing of the respective contractions, is very important to prevent the patient from adverse effects resulting from asynchronous contractions. Thus, in addition to providing the necessary pacing and defibrillation charges, it is extremely beneficial to have a system which can effectively preserve synchronization of the atrial and ventricle contractions by properly sensing the atrial depolarization and properly timing the electrical stimulus to the ventricle.
One method of obtaining the additional sensory information required to provide synchronization has been through the utilization of an atrial sensing lead, to provide sensing within the atrial cavity, which provides additional information to the pacemaker. The atrial sensing lead may simply be implanted and allowed to freely float within the atrial cavity. However, the disadvantages of having a second intravenously implanted lead include the fact that more hardware is implanted, perhaps to the detriment of cardiac function and optimal blood flow, in addition to the potential problems with its placement or implant location.
Accordingly, it would be very beneficial to provide a pacing system and cardioversion or defibrillation system which utilizes an improved pacing and defibrillation lead, having the additional capability of being able to sense atrial electrical activity, thereby assisting the preservation of the atrial/ventricular synchronization while eliminating the need for an additional atrial sensing lead.
SUMMARY OF THE INVENTION
The present invention details a pacing and defibrillation lead, for use in combination with an implanted pulse generator which may be a pacemaker or defibrillator or combination thereof. The lead can deliver a variety of electrical charges to pace, cardiovert or defibrillate the heart. In addition, the lead also includes sensor electrodes capable of sensing stimuli in the ventricular cavity, including ventricular electrical activity, fluid flow, and pressure, with the use of one or more sensing electrodes. The lead allows cardioversion and/or defibrillation stimuli to be provided by a large surface area electrode located distally of the tip electrode, so as to be positioned within the ventricle, while also sensing ventricular activity, to allow the pulse generator to provide appropriately synchronized atrial-ventricular pacing, cardioversion or defibrillation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a pacing and defibrillation lead and pulse generator according to the present invention;
FIG. 2 depicts an enlarged view of a portion of the proximal end of the lead of FIG. 1;
FIG. 3 depicts an enlarged view of a first connector at the proximal end of the lead of FIG. 1;
FIG. 4 depicts an enlarged view of a second connector at the proximal end of the led of FIG. 1;
FIG. 5 depicts the tip electrode at the distal end of the lead of FIG. 1;
FIG. 6 depicts a view of the tip electrode of FIG. 5 wherein the helical tip electrode is extended; and
FIG. 7. depicts an implanted pulse generator interconnected via plural leads, including the lead of FIG. 1, to a heart.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 depicts an implanted signal processing and pulse generator means, such as a pulse generator 10 which is preferably a pacemaker and/or defibrillator, and a pacing lead 20 according to the present invention. The pacing lead 20 includes a proximal end 22 and a distal end 24. At the proximal end 22, a connector assembly 26 accommodates interconnection with the pulse generator 10. At the distal end 24 of the pacing lead 20 is located a tip electrode 28, sensor electrode 102, and a defibrillation electrode 30. A lead body 32 interconnects the proximal end 22 and the distal end 24 of the pacing lead 20.
The detailed construction of the proximal end 22 of the pacing lead 20, including the connector assembly 26, is illustrated in the cross-sectional views of FIG. 2-4. Initially, it is to be understood that the lead 20 of the present invention is designed for use with a variety of pulse generators 10. This is important because while the design of lead 20 is unconventional, the capability to function as a pacing lead and as a defibrillation electrode allow substitution for prior designs using multiple leads.
Generally, the pulse generator 10 has a first connector port 12 for receiving a connector means of a pacing lead having a pacing electrode at its distal end and a pin-type electrical connector at the proximal end. This first connector port 12 may also include electrical contacts for receiving electrical signals from sensor electrodes on the lead 20, which are interconnected via conductors to electrical contacts on the connector means. The electrical contacts are preferably spaced distally of the pin connector for the pacing electrode.
The pulse generator 10 may also include a second connector port 16 adapted to receive a connector means for a lead extending to a defibrillation electrode. The defibrillation lead generally includes a pin type connector which plugs into a receiving sleeve in the second connector port 16.
In view of the construction of the pulse generator 10, the connector assembly 26 of the pacing lead 20 includes a divider boot 38, which allows the lead 20 to split into two segments 40 and 42, which terminate at connector means such as first connector 44 and a second connector 46, respectively. The first connector 44 plugs into the first connector port 12, and is therefore connected to the pacing electrode. The second connector 46 plugs into the second connector port 16 and is therefore connected to the defibrillation electrode.
The divider boot 38 is shown in the partial cross sectional view of FIG. 2. The divider boot 38 includes an encasement 48 of biocompatible material which is securely affixed about the lead body 32 at one end, and is affixed about both of the segments 42 and 44 at an opposite end. Within the divider boot 38, a defibrillation conductor 52 is illustrated as being wrapped about insulation material 50 which encases the remaining conductors (not shown), at the distal side of the divider boot 38. However, midway along the length of the divider boot 38, the defibrillation conductor 52 diverges, and continues proximally within an insulator 54, to form the segment 42 which terminates at the second connector 46.
The segment 40 extends from the divider boot 38 and terminates at the first connector 44, as depicted in FIG. 3. The first connector 44 includes a connector pin 56 extending into a connector boot 58. The connector pin 56 is securely interconnected to a pacing conductor 60, which terminates at the distal end of the lead 20 at the tip electrode 28 (FIG. 1). The sensor electrode 102 is preferably at least one ring electrode. The connector boot 58 is preferably formed from a biocompatible plastic or elastomeric material such as, for example, silicon, and may include a plurality of sealing rings 62 and a connector grip area 64 extending a short distance from the connector pin 56.
The conductor 60 is encased in an insulation material 66. The conductor 60 is preferably a helically wound coil of multifilar conductors which are braided about a silver core (not shown). The helically wound coil defines a hollow central portion, extending through the center of the helix, which is in open communication with an axial bore 68 in the connector pin 56, allowing for the insertion of a stylet or guidewire (not shown) useful for allowing the proper implanting of the pacing lead 20.
The second connector 46 is shown in the detailed cross sectional view of FIG. 4. The second connector 46 includes a connector pin 70 extending into a connector boot 72. The connector pin 70 is securely interconnected to the defibrillation conductor 52. The connector boot 72 is preferably formed from a biocompatible plastic or elastomeric material such as, for example, silicon, and may include a plurality of sealing rings 74 and a connector grip area 76 extending a short distance from the connector pin 70. The defibrillation conductor 52 transitions from being encased in the insulation material 54 into the connector boot 72. The defibrillation conductor 52 is preferably helically wound, and has multifilar conductors which are braided about a silver core (not shown).
FIG. 5 depicts an enlarged cross-sectional view of the distal end 24 of the pacing lead 20. In FIG. 5, the defibrillation electrode 30 is illustrated as being a coil 80 wrapped about the insulation material 50 which encases the pacing conductor 60. Preferably, the coil 80 of the defibrillation electrode 30 is formed from a platinum-iridium wire. The coil 80 is electrically connected to the defibrillation conductor 52 at the proximal end of the coil 80, via a connector element 84. The connector element 84 also securely interconnects the defibrillation electrode coil 80, to the insulation sleeve 82 encasing the conductor 52, as well as to the insulation material 50 about which the coil 80 is wrapped. The connector element 84 includes an axial bore 86 through which the remainder of the lead body components pass prior to entering the central portion of the coil 80.
At the distal end 24 of the lead 20, the tip electrode 28 is shown retracted into a sleeve 88. The sleeve 88 is preferably formed from a silicone rubber material. The tip electrode 28 is preferably an active fixation corkscrew or helix electrode which is advanceable from the end of the sleeve 88. The tip electrode 28 is affixed to a conductive element 90. The conductive element 90 is also securely affixed to the pacing conductor 60 extending axially through the defibrillation coil 80 and insulation sleeve 50 of the defibrillation electrode 30, and through the lead body 32 to the first connector 44.
FIG. 6 depicts the tip electrode 28 extended or advanced from the sleeve 88, as it would be following implantation. The tip electrode 28 may be advanced by the physicians rotation of the connector pin 56 (FIG. 3) which causes the entire pacing conductor 60 to rotate. Alternatively, a stylet (not shown) may be inserted axially through the lead 20 to rotationally advance the tip electrode 28.
Returning to FIG. 5, a third conductor such as a sensor conductor 100 may extend the length of the lead body 22, to interconnect a sensor electrode 102 and an electrical contact 104 in the first connector 44. The sensor electrode 102 is preferably located between the defibrillation electrode 30 and the sleeve 88. The first connector 44 further includes a ring connector 104 electrically connected to a sensor conductor 100, which terminates at the distal end of the lead 20 at the sensor electrode 102 (FIG. 1). The sensor electrode 102 is spaced from the defibrillation electrode 30 a distance of between 1 and 5 centimeters. Following implant of the pacing lead 20, the defibrillation electrode 30 will be positioned within the ventricle, as will the sensor electrode 102.
For any of the foregoing embodiments, the defibrillation electrode 30 may include a coating deposited on the coil 80, the material for the coating being platinum black, carbon, titanium or titanium nitride. The defibrillation electrode 30 has a total surface area in the range of between about 0.5 and 10 square centimeters, with a preferred size of between 2 and 4 square centimeters.
In addition or in the alternative, the tip electrode 28 and/or the defibrillation electrode 30 may be coated with a biocompatible, hypo-inflammatory material. Preferred biocompatible, hypo-inflammatory materials which can be used as coatings include soluble starches such as amylodextrin and amylogen, proteins such as collagen, albumin and gelatin. These protein materials may be cross-linked with a crosslinking agent such as 1-ethyl-3-(3-dimethylaminopropyl), carbodiimide, hydrochloride. Additionally, ion exchange materials such as polyethylenimine, poly-sodium styrenesulfonates, and sulfonated polytetrafluoroethylene sold under the tradename NAFION by the DuPont Corporation. These materials are preferred because of the ability of the body to resorb them without adverse effect.
Polymeric systems including polyethylene oxide or glycol, polypropylene oxide or glycol, polypropylene glycol, polysorbates, poly-vinylalcohol, and copolymers of ethylene oxide/propylene oxide can also be used as the coating material, and can deliver therapeutic agents by co-dissolution due to the inherent solubility of these materials.
The coating material is preferably a mixture of one of the above materials blended with an anti-inflammatory agent such as fluoro-trihydroxy-methyl pregna diene/dione or fluoro-methylprednisolone, sodium phosphate, the sodium salt of methoxy-methylnaphthalene-acetic-acid, sodium or the sodium salt or forms of dexamethasone sodium phosphate of isobutylphyl-propionic acid. The anti-inflammatory agents can constitute between about 1% to 95% by weight of the coating material, preferably however, the anti-inflammatory agents constitute in the range of between 5% and 50% by weight of the coating material.
FIG. 7 depicts a partially cut-away view of an implanted signal processing and pulse generating means such as the pulse generator 10 interconnected via lead 20, and a patch electrode lead 160 to a heart. The lead 20 is illustrated as being transvenously inserted and extending to the right ventricle. The pacing lead 20 includes an electrode assembly which includes the tip electrode 28 in combination with a coil type defibrillation electrode 30. The tip electrode 28 is preferably used with the pulse generator 10 to provide a pacing electrical output to the heart, and also to sense normal pacing electrical activity, in either a unipolar or bipolar arrangement. If a bipolar arrangement is used for pacing, the tip electrode 28 may act as the cathode with the defibrillation electrode 30 acting as the anode. For defibrillation, the defibrillation electrode 30 of the lead 20 may act as the cathode with the tip electrode 28 acting as the anode.
As further illustrated in FIG. 7, the patient may also have the patch electrode lead 160, which terminates at a patch electrode 162 affixed to the epicardial surface of the heart, to provide a large electrode useful for acting as either the anode or cathode in a unipolar or bipolar cardioversion or defibrillation. It may also be placed near the heart in a subcostal or subcutaneous site. The patch electrode lead 162 is also interconnected to the pulse generator. For a patient which is equipped with both of the leads depicted in FIG. 7, it may be appreciated that cardioversion or defibrillation can be accomplished by any combination of the primary electrodes, including the tip electrode 28 of lead 20, the defibrillation electrode 30 or the patch electrode 162 of patch electrode lead 160. While given a sufficient charge, any combination of the foregoing primary electrodes would operate to defibrillate a heart, a key aspect of minimizing the battery drain required for a defibrillation or cardioversion requires that the attending doctor determine which combination of electrodes will result in the lowest current threshold required for defibrillation. Thus, the doctor may sequentially test the defibrillation threshold using each of the major electrodes successively as the cathode and/or anode.
In view of the foregoing detailed description, the present invention contemplates a method of delivering an electrical stimulus to a heart. The method includes implanting a pulse generator, implanting a pacing lead extending through a vein and terminating at a tip electrode positioned within the ventricle abutting or extending into the myocardium of the heart, sensing the electrical activity of the heart, and delivering an electrical charge generated by the pulse generator through the pacing lead and the defibrillation electrode 30 to the heart. The method further contemplates delivering the electrical stimulus so as to maintain ventricular-atrial synchronization. Additionally, the method also contemplates sensing atrial activity utilizing sensor electrodes located on the pacing lead proximally spaced from the defibrillation electrode.
The foregoing methods may also require affixing a patch electrode to the epicardial surface of the heart or placing it subcostally or subcutaneously and interconnecting the patch electrode to the pulse generator, and operating the defibrillation electrode and the patch electrode in cooperation with the pulse generator as a bipolar charge delivery system to pace, defibrillate or cardiovert the heart.
It should be evident from the foregoing description that the present invention provides many advantages over leads and pacing or defibrillating systems of the prior art. Although preferred embodiments are specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teaching to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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A lead, for use in combination with an implanted pulse generator which may be a pacemaker or defibrillator or combination thereof. The lead can deliver an electrical charge to pace, cardiovert or defibrillate the heart, and can sense cardiac activity in the heart. The lead may include additional sensor electrodes capable of sensing electrical or physical activity in the atrial cavity. The lead allows cardioversion and/or defibrillation stimuli to be provided by a large surface area electrode which is passively implanted in the ventricle, to allow the pulse generator to provide appropriately synchronized atrial-ventricular pacing, cardioversion or defibrillation.
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BACKGROUND OF THE INVENTION
The invention described herein relates to a method for photochemically reducing uranyl ion in solution in tri-n-butyl phosphate, and more particularly to an improvement in the Purex process for treating irradiated nuclear fuels to recover uranium and plutonium values therein wherein the U(IV) produced by the photochemical reaction of uranyl nitrate with tri-n-butyl phosphate reduces the plutonium partitioned in the tri-n-butyl phosphate from Pu(IV) to Pu(III).
The Purex process for the treatment of irradiated, spent nuclear fuels to recover uranium and plutonium values therefrom has been in large scale use for over 20 years and is currently employed, with minor variations, by most of the nuclear fuel reprocessing plants now operating throughout the world. It is based on solvent extraction, i.e., the partitioning of a solute between two immiscible liquids. Tri-n-butyl phosphate (TBP) extracts uranium in the +6 oxidation state as the uranyl (UO 2 2+ ) ion and plutonium in the +4 oxidation state from aqueous solution, while extracting the other components of spent nuclear fuel to a much lesser degree. Plutonium in the +3 oxidation state is more soluble in the aqueous phase so that the plutonium in the TBP may be selectively partitioned into an aqueous stream by reducing the Pu(IV) to Pu(III). In practice, approximately a 30% solution of TBP in a suitable diluent, e.g., kerosene or normal dodecane, is used as the organic phase. By the addition of appropriate oxidizers, reducers, and salting-out reagents, the uranium and plutonium can be removed from the dissolved fuel elements and separated from each other.
The prior art teaches that a suitable agent for reducing the plutonium from the +4 to the +3 oxidation state is ferrous sulfamate, Fe(SO 3 NH 2 ) 2 , which is effective because Fe(II) rapidly reduces Pu(IV) to Pu(III) and because the sulfamate ion stabilizes Pu(III). But ferrous sulfamate has the disadvantage of introducing nonvolatile constituents, i.e., sulfur and iron, into the process wastes. These constituents increase the volume of radioactive wastes to be stored and may accelerate the corrosion of evaporators.
An alternative approach is the use of U(IV) as the reductant for the Pu(IV). It is known that the ferrous sulfamate can readily be replaced with uranium(IV) nitrate or uranium sulfate. See, e.g., Schlea et al., "Uranium(IV) Nitrate as a Reducing Agent for Plutonium(IV) in the Purex Process," E. I. du Pont de Nemours & Company Savannah River Laboratory report DP-808 (1963). The addition of these salts, however, also increases the volume of the waste and has the added disadvantage of altering the isotopic ratio of the uranium that is recovered.
To avoid these problems, electrolytic reduction of the Pu(IV) is used in a rather recent variation of the Purex process. This approach, however, requires the use of a special partitioning column containing the necessary electrodes. It will be readily apparent that in the event of a malfunction, repair of the column is not easily achieved because of the contamination produced by the uranium and plutonium.
A simpler approach is to use photolysis for the reduction of uranyl ion by organic reductants. See, e.g., J. C. Carroll et al., "The Photochemical Reduction of Uranium(VI) to Uranium(IV) Nitrate," Hanford Atomic Products Operation report HW-70543(1961). While such reduction is known to occur in the presence of a variety of organic reagents, the literature appears contradictory as to whether it has in fact been shown to occur with TBP used as the reductant. Thus, Kertes et al. expressly state that in nitric acid systems with either the neutral or acidic butyl esters of phosphoric acid, no photosensitized reduction of U(VI) takes place. See J. Inorg. Nucl. Chem., vol. 19, pp 359-362 (1961). But Minc et al. infer that in the presence of ultraviolet radiation, TBP reduces U(VI) in uranyl nitrate to U(V) and that this in turn undergoes a disproportionation reaction resulting in the formation of U(IV) and U(VI). See Nukleonika, vol. 5, pp. 33-45 (1960). Brzeski teaches that in the presence of strong ultraviolet radiation and the absence of oxygen, uranyl nitrate in solution in TBP is reduced to U(IV). He further indicates that such reduction does not occur with light in the visible spectrum. See Nukleonika, vol. 6, pp. 649-658 (1961).
SUMMARY OF THE INVENTION
We have now found that uranyl ion in solution in TBP is readily reduced to U(IV) by irradiating the solution with visible light in the spectral range of 350 nm to 520 nm. The U(IV) thus produced can readily be used as a reductant for Pu(IV) to Pu(III) in the Purex process for treating irradiated, spent nuclear fuel elements to separate the fission products, uranium, and plutonium contained therein. The acidity of the feed solution affects the amount of U(IV) produced, with best results obtained with feed solutions about 1.0 M in HNO 3 ; however, the reduction readily occurs at higher acid concentrations, reaching a minimum at about 4.0 M HNO 3 content and staying constant at this minimum at still higher acid concentrations.
In one embodiment of the invention as applied in the Purex process, a TBP solution of uranyl ion and Pu(IV) partitioned from the aqueous feed solution is irradiated directly with visible light in a preferred wavelength range. In another embodiment, a TBP solution of uranyl ion obtained in accordance with the Purex process is irradiated with visible light in a preferred wavelength range and the product U(IV) in solution in TBP is added to the Purex stage in which the TBP solution contains both uranyl ion and Pu(IV). A preferred wavelength of the irradiating light is one at which the photolytic production of NO 2 - from NO 3 - and its subsequent interaction with the product U(IV) is minimized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified flow chart of the Purex process as taught in the prior art.
FIG. 2 shows U(IV) yield as a function of HNO 3 concentration in the initial aqueous phase.
FIG. 3 is a compilation of the spectra of the xenon lamp output, transmission of the glass filters used, and UO 2 (NO 3 ) 2 in TBP.
FIG. 4 is a spectrum of TBP extract from 0.025 M NaNO 2 with 0.01 N HNO 3 in water.
FIG. 5 shows spectra of a TBP solution of uranyl ion before and after photolysis in accordance with the invention.
THE PUREX PROCESS
FIG. 1 is a simplified flow chart of the Purex process as taught in the prior art. The fuel elements are first chopped into small pieces and then treated with concentrated nitric acid. The metallic cladding does not dissolve and is mechanically removed. Before the extraction of uranium and plutonium (Stage I), NaNO 2 is added to the feed solution to ensure that the plutonium is in the +4 oxidation state. In Stage I most of the uranium and plutonium are separated from most of the other actinides and fission products. The uranium and plutonium are separated from each other (Stage II) by reducing the plutonium to the +3 oxidation state and extracting it into an aqueous strip. This separation is not complete, and a small amount of plutonium is carried on to Stages III and IV. In Stage III, the uranium and traces of plutonium and fission products are stripped from the TBP into water, which is then evaporated to the desired concentration and the acidity adjusted. The uranium is next separated from the remaining plutonium and fission products by reduction of the plutonium to the +3 oxidation state and extraction of the uranyl ion into TBP. The uranium is again stripped from the TBP (Stage V) and purified by ion exchange to UO 2 (NO 3 ) 2 product. The aqueous stream from Stage II contains most of the plutonium and a trace of the fission products. The plutonium is reoxidized to the +4 state and extracted into TBP (Stage VI), after which it is again reduced to Pu 3+ , stripped from the TBP, and purified by ion exchange to the Pu(NO 3 ) 3 product.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Measured portions of TBP and an aqueous solution of uranyl nitrate and nitric acid were placed in a separatory funnel and shaken. The aqueous layer was drawn off, and the organic layer was centrifuged to complete the separation of the phases. The organic layer was then exposed to light from a high-pressure xenon lamp (Oriel, 150 W), either unfiltered or filtered through a Corning glass filter (filters 0-52, 3-74, and 7-60). Uranyl and U(IV) concentrations were measured spectrophotometrically in a Beckman Acta MIV UV-Vis spectrophotometer. Spectra of the starting solution and the photolyzed solution were recorded from 850 to 300 nm. Calibration curves were determined for the concentration of UO 2 2+ in water and TBP. Uranium(IV) concentrations were also determined colorimetrically.
The photolytic yield of U(IV) as a function of HNO 3 concentration in the aqueous phase before extraction is shown in FIG. 2. The points labeled "direct measurement" were obtained by colorimetric analysis for U(IV). The points labeled "calculated from absorbance" were obtained by measuring the absorbance at the U(IV) maximum near 650 nm and calculating the concentration from a calibration curve for the appropriate HNO 3 concentration obtained by analyzing photolyzed solutions by the colorimetric method. For nitric acid concentrations of 1.0 M and higher, the U(IV) formed remains in solution. For 0.5 M nitric acid and solutions in which no acid was added, a precipitate is formed. Because of this precipitate, it was not possible to determine the total amount of U(IV) formed for those solutions, and erratic analyses were obtained for the U(IV) remaining in solution (see FIG. 2). Above 1.0 M, increasing acid concentration results in a decreasing yield of U(IV) to a minimum at 4.0 M, which remains the same for higher acid concentrations. The reduction does not take place in an aqueous solution of UO 2 (NO.sub. 3) 2 with a small amount of TBP present. Deoxygenation of the solutions by bubbling N 2 through them gives the highest yields of U(IV). However, static solutions, i.e., those which have not been deoxygenated, are also readily photolyzed, although with lesser yields of U(IV).
The light from the xenon lamp was filtered to allow photolysis at wavelengths less than 400 nm, greater than 350 nm, and greater than 400 nm. The lamp output was greatest at the higher energies. FIG. 3 summarizes the spectrum of the lamp and the transmission of the three filters, with the spectrum of UO 2 (NO 3 ) 2 in TBP for comparison. The Table gives results of typical experiments with and without the filters.
Table______________________________________HNO.sub.3 Concn. A.sub.max(N) No Filter 7-60 0-52 3-74______________________________________0.sup.a 0.428 0.129 0.340 0.410 1.0.sup.b 1.095 0.245 0.943 0.598 3.0.sup.b 0.230 0.053 0.494 0.325______________________________________ .sup.a A.sub.max measured at 635 nm .sup.b A.sub.max measured at 654 nm
Infrared spectra of the products indicate that butanol and butyraldehyde are probably present in the products. Nitrite was detected in all of the photolyzed solutions by the Griess test. The U(IV) reoxidizes upon standing in the TBP solutions, more rapidly in the more acid solutions. The solutions of lower acidity retained U(IV) for days. The solutions were stored in clear glass stoppered bottles, exposed to air and ambient light conditions in the laboratory.
The photolysis was also carried out in a 30% TBP solution in normal dodecane. Extraction from a 0.1 M UO 2 (NO 3 ) 2 , 1.0 M HNO 3 solution followed by photolysis gave increasing amounts of U(IV) for the first four hours. The U(IV) then decreased under further illumination. Nitrite was observed. Extraction from a 1.5 M UO 2 (NO 3 ) 2 , 1.0 M HNO 3 solution followed by photolysis gave a reddish-brown solution with a UV-Vis spectrum indicating the presence of U(V). Nitrite was produced in the early part of this photolysis, but after six hours irradiation, none could be detected. The product UV-Vis spectrum in both cases reverted to the UO 2 2+ spectrum after two to three days.
A solution of HNO 3 in TBP was prepared by extraction from an aqueous solution and photolyzed for 6 hours. A control solution was kept in the dark for the same amount of time. HNO 2 was formed by photolysis, but not in the dark. A UV-Vis spectrum showed a series of sharp peaks beginning at 400 nm. Tri-n-butyl phosphate extraction of a NaNO 2 solution showed a similar series of peaks. Spectra of TBP solutions prepared by extraction of an acidic aqueous NaNO 2 solution (0.025 M NaNO 2 , 0.01 N HNO 3 ) is shown in FIG. 4. Peaks are also observed at these positions in the UV-Vis spectra of the photolyzed UO 2 (NO 3 ) 2 -TBP solutions. FIG. 5 gives the spectra of a typical solution before and after photolysis.
From the foregoing, it is apparent that reduction of UO 2 (NO 3 ) 2 takes place readily under the influence of light in TBP at various HNO 3 concentrations. Nitric acid is also reduced to HNO 2 , and hydrolyzed and oxidized products of TBP are formed. Reoxidation of the U(IV) formed by the uranyl reduction also takes place. Such reoxidation presumably occurs primarily by reaction with NO 2 - . This in turn appears to account for the decreasing U(IV) yield with increasing HNO 3 concentration.
The wavelength dependence of the photolytic reduction of uranyl to U(IV) in the presence of TBP is shown by the data of the Table. Although the output of the lamp is much more intense at wavelengths below 400 nm, the photochemical yield is much less at the lower wavelengths than for irradiation above 400 nm. In fact, for solutions containing 3.0 N HNO 3 , more U(IV) is produced with filtered lamp output than with unfiltered light. Nitrite production, from examination of the UV-Vis spectra, seems to be similar with and without filters, although it varies with acid concentration.
The exact mechanism by which the U(IV) is produced is not known. However, the electronic transition (or transitions) in the uranyl ion between 520 and 350 nm seems to be responsible for the photochemical reaction. The reaction resulting from the more intense, higher-energy transitions may come about through relaxation to the lower-energy, chemically reactive state (or states). In addition, reoxidation of the U(IV) takes place with NO 2 - , which absorbs at wavelengths less than 400 nm, and perhaps NO 3 - , which absorbs at wavelengths shorter than 350 nm. Elimination or at least a lessening of this reaction accounts for the greater yields from filtered light.
The participation of NO 3 - or NO 2 - in the reduction of UO 2 2= is not entirely clear, but there is evidence for photochemical oxidation of the product U(IV) by one or both. The action of NO 2 - and NO 3 - in oxidizing U(IV) is taught in the art. Because the production of NO 2 - or its interaction with U(IV) is affected by the wavelength of the irradiating light, it is preferable that the photolysis of the UO 2 2+ takes place with light of a wavelength at which this interaction is minimized.
The overall reaction is sensitive to changes in concentration of the reagents, but no conditions have been found under which no photochemical reaction took place. At high UO 2 (NO 3 ) 2 loadings of the TBP, reduction to U(V) rather than to U(IV) takes place, albeit with little or no nitrite production.
Photolytic reduction of UO 2 2+ to U(IV) may advantageously be employed in the Purex process as a means of reducing Pu(IV) to Pu(III) and thereby facilitating the separation of plutonium from uranium in accordance with the process. As taught in the prior art, U(IV) reduces Pu(IV) to Pu(III). The U(IV) produced by the photolytic reduction of UO 2 2+ is stable for periods ranging from hours to days, depending on the nitric acid concentration. This permits considerable leeway as to the stage of the Purex process at which the irradiation is performed. Thus, for example, the irradiation may occur between Stages I and II of FIG. 1. In this instance it will be apparent that no reducing agent need be added to Stage II since the U(IV) formed as a result of the photolysis will effectively act as a reducing agent for the plutonium.
Alternatively, the irradiation may occur between Stages IV and V. The U(IV) thereby produced may be removed from Stage V and fed into Stage II as the reducing agent. The amount of the U(IV) necessary to effectively act as the reducing agent can be fed continuously from Stage V or can be temporarily stored and fed into Stage II as required. Typically, the amount of U(IV) required is three to five times the amount of Pu(IV) present in Stage II.
Regardless of at what stage the irradiation occurs, the process of the invention has the following advantages as applied to the Purex process. Visible light from commercially available lamps may be used to produce the photochemical reaction. This in turn means that readily available glass windows may be used for irradiation of the feed solution. The products of reaction are the same as those resulting from radioactive degradation of the feed solution and can be handled by normal solvent cleanup procedures for the Purex process. Finally, no reagents need be added, so that the bulk of waste in the Purex process is reduced.
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Uranyl ion in solution in tri-n-butyl phosphate is readily photochemically reduced to U(IV). The product U(IV) may effectively be used in the Purex process for treating spent nuclear fuels to reduce Pu(IV) to Pu(III). The Pu(III) is readily separated from uranium in solution in the tri-n-butyl phosphate by an aqueous strip.
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CLAIM OF PRIORITY
This divisional application claims priority from U.S. patent application Ser. No. 11/701,304, filed on Jan. 31, 2007, which is incorporated herein by reference in its entirety.
GOVERNMENT RIGHTS
Embodiments were made with Government support under Agreement No. N00019-04-C-3146 awarded by the Naval Air Systems Command. The Government has certain rights therein.
BACKGROUND
Stores, such as sonobuoys and countermeasures, can be deployed from vehicles, such as aircraft, surface ships, and submarines, in a variety of manners. As an example, to minimize loads on a sonobuoy during deployment, some aircraft launch systems are oriented such that stores are ejected at an aft swept angle to reduce incident air loads. This practice, however, can cause interference with structural members and, increase the weight of the launcher system. Therefore, launching at 90 degrees is desirable. As a further example in the case of sonobuoys, it is desirable to store a sonobuoy in its Sonobuoy Launch Container (SLC), thereby extending shelf life of the sonobuoy, and to eject the sonobuoy directly from the SLC.
The SLC is larger in diameter than the sonobuoy itself, and the sonobuoy rests on a bottom plate of the SLC. For store deployment from an SLC to occur, both the sonobuoy and the bottom plate must be ejected through a sonobuoy launch tube before departing an aircraft. The diameter of the sonobuoy launch tube must be large enough to accommodate the bottom plate (that has a diameter that is larger than the diameter of the sonobuoy). As a result, desirable load-reducing tolerances nominally close to diameter of the sonobuoy can not be maintained, and the sonobuoy can rotate within the sonobuoy launch tube during transit.
These rotations occur due to airloads that laterally push on the sonobuoy as it begins to emerge from the sonobuoy launch tube at the bottom of the aircraft. For example, an airstream force is roughly proportional to an exposed portion of the store. As the buoy rotates and clearances are taken up, contact with the launch tube will occur at the aft bottom edge of the launch tube and upper leading edge of the sonobuoy, causing local shear and moment loads. A friction force also occurs at these upper and lower bearing surfaces.
The airloads do not keep the buoy to one side, but can cause multiple impacts to occur as the sonobuoy bangs repeatedly into the sonobuoy launch tube during exit. These impacts can possibly result in shock loading outside of levels for which the sonobuoys are qualified.
Some attempts have been made to deal with problems associated with loading on sonobuoys during launch. For example, sonobuoys are launched from P-3C Orion maritime patrol aircraft at around a 55 degree angle from vertical to avoid buoy load problems. As discussed above, use of an angled launch system can cause interference with structural members and can increase weight of the launcher system. In other air vehicles, such as the Nimrod, sonobuoys are removed from their sonobuoy launch containers and are vertically launched from smaller-diameter launch tubes.
The foregoing examples of related art and limitations associated therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
SUMMARY
The following embodiments and aspects thereof are described and illustrated in conjunction with systems and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the problems described above in the Background have been reduced or eliminated, while other embodiments are directed to other improvements.
In an exemplary embodiment, a stores launch tube comprises a tube member and a flexible seal. The flexible seal is coupled to an exterior of the tub member such that the flexible seal couples the exterior of the tube member to full and the flexible seal acts as a pressure barrier against an ambient environment.
According to another aspect, a method is disclosed for ejecting a store from a vehicle. A store is received into a first end of a launch tube where the second end of the launch tube is secured by a seal to an opening in a hull of the vehicle. The store is released, causing the store to pass through the second end of the launch tube into an ambient atmosphere outside the hull. At least a portion of the launch tube moves relative to the store to reduce a load caused by relative motion of the fluids in the ambient atmosphere that apply one or more forces to the store causing the store to apply the load to the launch tube.
According to still another aspect, a method is disclosed for reducing an impact force imparted to a store upon being ejected from a moving vehicle. A store is launched from a stores launch system of a moving vehicle toward an ambient atmosphere outside a hull of the moving vehicle. The ambient atmosphere includes a fluid. In response to at least a portion of the store contacting the fluid, an impact force between the store and the stores launch system resulting from a force applied to at least the portion of the store contacting the fluid.
In addition to the exemplary embodiments and aspects described above, further embodiments and aspects will become apparent by reference to the drawings and by study of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
FIGS. 1A and 1B are cross-sectional side views of exemplary embodiments of stores launch tubes;
FIGS. 2A , 2 B, and 2 D are cross-sectional views of further exemplary embodiments of stores launch tubes;
FIG. 2C is a top view of a portion of the stores launch tube of FIG. 2B ;
FIGS. 3A , 3 B, 3 C, 3 D, 3 E, 3 F, 3 G, and 3 H are cross sectional top views of the exemplary stores launch tubes of FIGS. 1A , 1 B, 2 A, 2 B, and 2 D;
FIGS. 4A , 4 B, and 4 C illustrate operation of an exemplary stores launch tube;
FIGS. 5A , 5 B, 5 C, and 5 D illustrate exemplary load-reducing features;
FIG. 6 is a cross-sectional side view of another exemplary stores launch tube;
FIGS. 7A , 7 B, and 7 C illustrate vehicles that include an exemplary stores launch tube; and
FIG. 8 illustrates an exemplary stores launch system.
DETAILED DESCRIPTION
Given by way of overview, in an exemplary embodiment, a stores launch tube includes an outer tube and an inner tube. The inner tube is disposed interior the outer tube and is configured to reduce load as a store exits therefrom. Thus, the exemplary stores launch tube can help reduce impact forces and bearing normal loads imparted to the store due to induced rotational moments as the store emerges from the launch tube. Details of exemplary embodiments and aspects thereof will be discussed below.
Referring now to FIG. 1A , a stores launch tube 10 A includes an outer tube 12 and an inner tube 14 . The inner tube 14 is disposed interior the outer tube 12 and is configured to reduce load as a store (not shown) exits therefrom.
The stores launch tube 10 A is a lower portion of a stores launch tube assembly that also includes an upper tube portion 18 that is attached to a stores launcher (not shown) and a normally shut gate valve 20 . The gate valve 20 is disposed toward a bottom end 22 of the upper tube portion 18 . The gate valve 20 operates in conjunction with a stores launcher (not shown) and opens to permit the store (not shown) to be ejected from an opening 24 in an outer mold line 26 of a vehicle (not shown) by the stores launcher.
The outer tube 12 can serve multiple functions. For example, the outer tube 12 can serve to provide backup stiffness for hung store loads which are generally higher than normal launch loads, can provide for longitudinal deflections due to vehicle deflections, and can also provide a seal for pressure loads induced by opening and closing the gate valve 20 within the tube at various altitudes. The outer tube 12 is a pressure boundary between the interior of the stores launcher and ambient environment. As such, the outer tube 12 has a thickness and is made of a material as desired for a particular application. Material selection for the outer tube 12 may also depend in part on corrosion considerations (such that dissimilar metal galvanic corrosion is mitigated). For example, when the vehicle is an aircraft and the ambient environment is air, the outer tube 12 may be made of aluminum, steel, or the like. When the vehicle is a surface ship and the ambient environment is seawater, the outer tube 12 may be made of steel or the like. When the vehicle is a submarine and the ambient environment is seawater under high pressure, the outer tube 12 may be made of steel, high-strength steel such as HY-80, titanium, or the like.
The outer tube 12 includes a flexible pressure seal 28 . The pressure seal 28 is located toward a lower portion 30 of the outer tube 12 . The pressure seal 28 extends around the entire periphery of the exterior of the lower portion 30 of the outer tube 12 . An exemplary, non-limiting example of the pressure seal 28 is described below. An upper portion 32 of the pressure seal 28 is attached, such as by welding, at an attachment portion 33 to the exterior of the lower portion 30 of the outer tube 12 . A lower portion 34 of the pressure seal 28 is attached, such as by welding, at an attachment portion 35 to the outer mold line 26 exterior the opening 24 .
An overlapping portion 36 of the upper portion 32 of the pressure seal 28 is urged against an overlapping portion 38 of the lower portion 34 of the pressure seal in sealing engagement, thereby maintaining a pressure seal and acting as a pressure barrier. The overlapping portion 36 is urged in sealing engagement against the overlapping portion 38 by a biasing portion 40 of the upper portion 32 . The overlapping portions 36 and 38 are maintained in sealing engagement with each other but are able to slide along each other. This sliding, sealing engagement maintains a pressure barrier while accommodating relative motion between the outer tube 12 and the outer mold line 26 . Such relative motion may arise due to pressure variations as the vehicle changes altitude in air or changes depth in water, or as the vehicle performs maneuvers that exert forces on the outer tube 12 or the outer mold line 26 .
The inner tube 14 is disposed interior the outer tube 12 and is configured to reduce load as a store (not shown) exits therefrom. In an exemplary embodiment, the inner tube 14 is able to reduce load because the inner tube 14 is made of flexible material and can flex, which distributes load over more of the buoy surface, and also reduces shock to the buoy by lengthening the duration of the restoring impulse from collision with the wall of the launch tube. Given by way of non-limiting example, the flexible material used for the inner tube 14 may include such flexible materials as an acetal homopolymer like DELRIN™, available from DuPont; a polytetrafluroethylene (PTFE) like TEFLON™, available from DuPont, or HOSTAPLON™, or CUFLON™; or a fluorocarbon such as a tetrafluroethylene (TFE) fluorocarbon like any of several formulations of RULON™. Other flexible materials may be used as desired for a particular application, provided that the flexible material provides a coefficient of friction sufficiently low enough to permit a store (not shown) to travel without binding through the inner tube 14 .
In an exemplary embodiment, the inner tube 14 may be provided as part of a unit, such as a canister 42 , that can be easily replaced. For example, the inner tube may be received within the canister 42 that has an outer casing 44 that is attachable to the outer tube 12 . The canister 42 may be made of any material as desired, such as for example aluminum, steel, or the like. In an exemplary embodiment, the casing 44 may be held in place by one or more fasteners 46 that are securely received (such as threadedly received) in an opening 48 (such as a threaded opening) in the outer tube 12 . The opening 48 may be located near the outer mold line 26 in order to provide for ease of access when installing or removing the canister 42 .
The inner tube 14 is attached at an attachment portion 50 to an interior of the canister 42 at an upper portion 52 of the canister 42 . In an exemplary embodiment, the attachment portion 50 is bonded to the upper portion 52 of the canister 42 with an adhesive that is appropriate for a desired application. Suitable types of adhesives depend on the type of flexible launch tube material chosen.
Flexing of the inner tube 14 is accommodated by an interstitial chamber 54 between the inner tube 14 and the casing 44 . The interstitial chamber provides a space through which the inner tube 14 can flex unimpeded as the store (not shown) emerges from the opening 24 and rotates due to forces exerted on the store by slipstream forces.
Referring now to FIG. 1B , an exemplary stores launch tube 10 B includes all of the features of the stores launch 10 A ( FIG. 1A ), but the interstitial chamber 54 optionally is at least partially filled with a soft filler material 56 , such as foam. If provided, the filler material 56 can help provide spring-like and energy dissipative qualities and/or can help reduce voids between the inner tube 14 and the outer tube 12 , depending on the mechanical properties of the filler material 56 selected. Filling the interstitial chamber 54 with the filler material 56 can enhance the function of the inner tube 14 , or not affect it at all, as desired. For example, certain types of filler material 56 , such as foam, can provide more stiffness and/or dampening to the inner tube 14 , if desired. Alternatively, other types of filler material 56 can be selected which do not affect stiffness or dampening of the inner tube 14 , but which do fill the interstitial chamber 54 at least partially so foreign objects—which could substantially affect flexing capability of the inner tube 14 —do not enter the interstitial chamber 54 . To that end, the interstitial chamber 54 need not be completely filled with the filler material 56 , if provided. The interstitial chamber 54 may be sealed sufficiently with the filler material 54 being provided just in a lower portion 58 of the interstitial chamber 54 . Alternatively, other means such a flexible membrane may be used to afford a seal between the inner tube 14 and the outer tube 12 , or between the inner tube 14 and the outer casing 44 . Like reference numbers are used to denote features of the stores launch tube 10 B in common with the stores launch tube 10 A ( FIG. 1A ), and their details need not be repeated for an understanding of the embodiment.
Referring now to FIG. 2A , a stores launch tube 10 C includes an outer tube 12 and an inner tube 14 . The inner tube 14 is disposed interior the outer tube 12 and is configured to reduce load as a store (not shown) exits therefrom. The stores launch tube 10 C includes many features in common with the stores launch tube 10 A ( FIG. 1A ) that are indicated by like reference numbers, and their details need not be repeated for an understanding of the embodiment. Unlike the stores launch tube 10 A ( FIG. 1A ), in the stores launch tube 10 C the inner tube 14 retained within the outer tube 12 without use of a unit such as the canister 42 ( FIG. 1A ). For example, an indexed retention ring 60 may be disposed within the inner tube 14 under an upper flange 62 of the inner tube 14 . The indexed retention ring 60 is fastened against the outer tube 12 with fasteners 64 . Fastening the indexed retention ring 60 against the outer tube 12 holds the upper flange 62 of the inner tube 14 securely against an upper flange 66 of the outer tube 12 .
Referring now to FIGS. 2B and 2C , the upper flange 62 of the inner tube 14 instead may be held securely against a lower flange 68 of the lower portion 22 of the upper tube portion 18 by a bracket 70 . The bracket 70 may include two bracket members 72 that each extend around half of the periphery of the exteriors of the flanges 62 and 68 . The bracket members are held together securely by fasteners 74 .
Referring now to FIG. 2D , an exemplary stores launch tube 10 D includes all of the features of the stores launch 10 C ( FIG. 2A ), but the interstitial chamber 54 optionally is at least partially filled with the soft filler material 56 , as described above. As discussed above, the interstitial chamber 54 need not be completely filled with the filler material 56 , if provided. The interstitial chamber 54 may be sealed sufficiently with the filler material 54 being provided just in a lower portion 58 of the interstitial chamber 54 . Like reference numbers are used to denote features of the stores launch tube 10 D in common with the stores launch tube 10 C ( FIG. 2A ), and their details need not be repeated for an understanding of the embodiment.
Referring now to FIGS. 3A through 3F , various embodiments of stores launch tubes may have various cross-sections, as desired for a particular application. While the outer tube 12 has been illustrated in the drawings, by way of non-limiting examples, as having either a circular cross-section or an oval cross-section, it is not intended that the outer tube 12 be limited to circular or oval cross-sections. No limitation whatsoever is intended regarding the cross-section of the outer tube 12 . Thus, the outer tube 12 can have any cross-section shape as desired that is consistent with the outer tube 12 performing its functions, such as providing backup stiffness for hung store loads which are generally higher than normal launch loads, or providing for longitudinal deflections due to vehicle deflections, or for providing a seal for pressure loads induced by opening and closing the gate valve 20 within the tube at various altitudes. With this context in mind and referring now to FIG. 3A , the outer tube 12 and the inner tube 14 of the stores launch tube 10 A each suitably have a substantially circular cross section and each are made of one-piece construction.
Referring now to FIG. 3B , the outer tube 12 and the inner tube 14 of the stores launch tube 10 A each suitably have a substantially circular cross section. The outer tube 12 is made of one-piece construction. If desired, the inner tube may be made of more than one piece. To that end, the inner tube 14 can be made of sections 14 A. Given by way of non-limiting example, the sections 14 A may be multiple segments with differing properties, as desired, or portions of a tube or tubes sliced longitudinally. While two of the sections 14 A are illustrated by way of non-limiting example, the number of the sections 14 A is not intended to be limited whatsoever. Any number of the sections 14 A may be used as desired to make up the inner tube 14 .
Referring now to FIG. 3C , the outer tube 12 and the inner tube 14 of the stores launch tube 10 A each suitably are made of one-piece construction. The inner tube 14 has a substantially circular cross section. If desired, the outer tube 12 has a substantially oval cross section. In this case, the exterior of the inner tube 14 abuts the interior of the outer tube 12 . This arrangement creates two substantially crescent-shaped interstitial chambers 54 A. Thus, a more slender (albeit slightly elongated) cross section than that illustrated in FIG. 3A can be obtained. Use of a substantially oval cross section for the outer tube 12 may be desired in the event of interference with structural members or other nearby systems or subsystems, or to achieve stiffness and or dampening effects limited by and/or tailored to the direction of load reduction only.
Referring now to FIG. 3D , the outer tube 12 suitably is made of one-piece construction and has a substantially oval cross section (as illustrated in FIG. 3C ). The inner tube 14 has a substantially circular cross section but is made of the sections 14 A. While two of the sections 14 A are illustrated by way of non-limiting example, the number of the sections 14 A is not intended to be limited whatsoever. Any number of the sections 14 A may be used as desired to make up the inner tube 14 .
Referring now to FIGS. 3E , 3 F, 3 G, and 3 H, the cross sections of the outer tube 12 and the inner tube 14 are the same as those illustrated in FIGS. 3A , 3 B, 3 C, and 3 D, respectively. However, the interstitial chambers 54 or 54 A, as appropriate, are at least partially filled with the filler material 56 , as described above.
Referring now to FIGS. 4A , 4 B, and 4 C, embodiments operate as follows. As shown in FIG. 4A , the gate valve 20 has been opened, and a store 76 , such as a countermeasure or a sonobuoy resting on a bottom plate 78 of its sonobuoy launch container (not shown), descends through the upper tube portion 18 and the stores launch tube 10 A, as shown by an arrow 80 .
As shown in FIG. 4B , the store 76 begins to emerge from the stores launch tube 10 A through the opening 24 at the outer mold line 26 . The bottom plate 78 (in the case of a sonobuoy that is launched from its sonobuoy launch container) falls away from store 76 . Slipstream forces, indicated by arrows 82 , cause the store 76 to begin to rotate (in a fore-aft manner) within the stores launch tube 10 A. When the store 76 has rotated sufficiently, it first contacts a lower, aft portion of the inner tube 14 , thereby resulting in a bearing stress on the store 76 . Because the inner tube 14 is made of flexible material, as described above, the inner tube 14 flexes rearwardly at lower portions of the inner tube 14 responsive to the fore-aft rotation of the store 76 . In this manner, rearward flexing of the lower portions of the inner tube 14 can help reduce bearing stress on the store 76 .
As shown in FIG. 4C , the store 76 continues to rotate in a fore-aft manner and the store 76 contacts an upper, forward portion of the inner tube 14 , thereby resulting in impact shock loads on the store 76 . Because the inner tube 14 is made of flexible material, as described above, the inner tube 14 can help reduce the impact shock loads. In addition, the inner tube 14 may flex forwardly at portions of the inner tube 14 near the area of impact with the store 76 responsive to the fore-aft rotation of the store 76 . In this manner, forward flexing of portions of the inner tube 14 can help reduce impact shock loads on the store 76 .
Referring now to FIGS. 5A , 5 B, and 5 C, at least one load-reducing device 84 , such as a spring, a piston, or a jet, may be disposed between the inner tube 14 and the outer tube 12 . The inner tube 14 should not be rigidly attached, but instead should be permitted to move freely, restrained only by the load reducing device 84 . A load-reducing device 84 may be disposed between an upper, forward portion of the inner tube 14 and the outer tube 12 to reduce impact shock loads on the store (not shown), and another load-reducing device 84 may be disposed between a lower, rearward portion of the inner tube 14 and the outer tube 12 (that is, at a radial position that is around 180 degrees from the load-reducing device at the upper, forward portion of the inner tube 14 ). However, as many of the load-reducing devices 84 may be provided as desired for a particular application.
Any type of load-reducing device may be used as desired for a particular application. Given by way of non-limiting example and without any intention of limitation, the load-reducing devices 84 may be provided in the form of springs ( FIG. 5A ), a spring-like material such as foam (not shown), pistons ( FIG. 5B ), fluid jets ( FIG. 5C ), or the like. As shown in FIG. 5C , a source of fluid (not shown) provides the fluid to a manifold 86 . Jets 84 receive the fluid from the manifold 86 . The fluid may be selected as desired for a particular application. For example, a gas such as air or an inert gas may be used as the fluid when the vehicle is an aircraft or a surface ship or a submarine. A gaseous fluid as described above or a liquid such as water or seawater may be used as the fluid when the vehicle is a surface ship or a submarine. Use of water or seawater as the fluid would provide for quieter operation for a submarine than use of a gaseous fluid (because gas bubbles would eventually collapse due to sea pressure, thereby causing cavitation-like noise). As shown in FIG. 5D , in another embodiment that includes the jets 84 no inner tube is necessary. In this embodiment, the outer tube 12 provides the pressure boundary and the jets 84 perform load-reduction functions of an inner tube.
The load-reducing devices 84 can reduce bearing stress and impact shock loads in addition to load reduction provided by the inner tube 14 when the inner tube 14 is made of a flexible material. If desired, the load-reducing devices 84 can reduce bearing stress and impact shock loads in lieu of load reduction provided by the inner tube 14 when the inner tube 14 is not made of a flexible material. In such a case, the inner tube 14 can be made of any material as desired for a particular application, such as aluminum, steel, titanium, or the like.
While the load-reducing devices 84 are illustrated in use with the stores launch tube 10 A, the load-reducing devices 84 can be used with any embodiment as desired. For example, the load reducing devices can be used with the stores launch tube 10 B ( FIG. 1B ) and the stores launch tube 10 D ( FIG. 2D ) when the filler material 56 ( FIGS. 1B and 2D ) does not interfere with the load-reducing devices 84 —such as when the filler material 56 serves only to seal the bottom of the interstitial chamber 54 ( FIGS. 1B and 2D ). Alternatively, the filler material 56 can serve as an enhancement to the stores launch tube 10 A by providing tailored stiffness and/or dampening.
Referring now to FIG. 6 , a stores launch tube 10 E includes a tube member 88 that is configured to reduce load as a store (not shown) exits therefrom. The stores launch tube 10 E includes many features in common with the stores launch tube 10 A ( FIG. 1A ) that are indicated by like reference numbers, and their details need not be repeated for an understanding of the embodiment. Unlike the stores launch tube 10 A ( FIG. 1A ), in the stores launch tube 10 E only the tube member 88 is provided. That is, the stores launch tube 10 E need not have a separate outer tube and inner tube. Instead, the stores launch tube 10 E includes a tube member 88 that is configured to reduce load as a store exits therefrom. The flexible seal 28 is coupled to an exterior of the tube member 88 and is arranged to cooperate with the tube member 88 to act as a pressure barrier to an ambient environment. In such an exemplary embodiment, a separate outer tube and a separate inner tube are not needed, and their functions can instead be satisfied with the single tube member 88 which can perform the functions related to impact and stress loading, hung store loading, and pressure differential loading. To that end, the tube member 88 is configured to flex as a store (not shown) exits therefrom, as described above for the inner tube 14 ( FIG. 1A ), while also meeting any or all other functions previously assigned to the outer tube 12 ( FIG. 1A ), such as acting as a pressure barrier, permitting axial movement, and providing adequate stiffness for hung store loads. For example, the stores launch tube 10 E could provide both soft (load relieving) and hard (hung store) stiffness attributes if a material with nonlinear stiffness characteristics is used for the tube member 88 , or through geometric considerations in tube construction. For example, bilinear stiffness could be achieved with a soft material encased by a stiff material with a gap between them. It will be appreciated that any of the functions performed by an outer tube can alternatively be performed by a single tube with no loss of functionality. In such a case, manufacturing costs and/or ease of production may help determine which approach is more desirable in a given application.
Referring now to FIGS. 7A , 7 B, and 7 C, any of the stores launch tubes described herein may be used in vehicles such as an aircraft, a surface ship, or a submarine. While not being intended to be limiting, the stores launch tube suitably is oriented substantially perpendicular to a fore-aft axis of the vehicle. However, it will be appreciated that in other embodiments the stores launch tube suitably is not oriented substantially perpendicular to a fore-aft axis of the vehicle and can be oriented as desired for a particular application. As shown in FIG. 7A , an aircraft 90 includes a fuselage 92 that defines a cabin 94 therein. A stores launching system 96 , such as a sonobuoy launching system, includes a stores launcher 98 , such as a sonobuoy launcher, provided in the cabin 94 and a load-reducing stores launch tube 100 , such as a sonobuoy launch tube, operatively coupled to the stores launcher 98 to receive therefrom a store, such as a sonobuoy, and then to eject the store. The load-reducing stores launch tube 100 suitably can include any of the exemplary stores launch tubes described above.
As shown in FIG. 7B , a surface ship 102 includes a hull 104 that defines a cabin 106 therein. A stores launching system 108 , such as a sonobuoy launching system or a countermeasures launching system, includes a stores launcher 110 , such as a sonobuoy launcher or a countermeasures launcher, provided in the cabin 106 and a load-reducing stores launch tube 112 , such as a sonobuoy launch tube or a countermeasures launch tube, operatively coupled to the stores launcher 110 to receive therefrom a store, such as a sonobuoy or a countermeasure, and then to eject the store. The load-reducing stores launch tube 112 suitably can include any of the exemplary stores launch tubes described above.
As shown in FIG. 7C , a submarine 114 includes a pressure hull 105 that defines a cabin 106 therein. An outer (non-pressure) hull 105 A defines an outer mold line. A stores launching system 108 , such as a sonobuoy launching system or a countermeasures launching system, includes a stores launcher 110 , such as a sonobuoy launcher or a countermeasures launcher, provided in the cabin 106 and a load-reducing stores launch tube 112 , such as a sonobuoy launch tube or a countermeasures launch tube, operatively coupled to the stores launcher 110 to receive therefrom a store, such as a sonobuoy or a countermeasure, and then to eject the store. The load reducing stores launch tube 112 suitably can include any of the exemplary stores launch tubes described above.
Referring now to FIG. 8 , the stores launching system 108 includes the stores launcher 110 . The stores launcher 110 can be any suitable, known stores launcher. Given by way of non-limiting example, the stores launcher 110 may be a rotary sonobuoy launcher as described in U.S. Pat. No. 7,093,802 or a radial sonobuoy launcher as described in U.S. Pat. No. 6,679,454, or any well-known single-load stores launcher, such as a countermeasures launcher. The stores may include a sonobuoy, a countermeasure, a smoke canister, a sound underwater signal (SUS) canister, or other type of store as desired.
While a number of exemplary embodiments and aspects have been illustrated and discussed above, those of skill in the art will recognize certain modifications, permutations, additions, and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, and sub-combinations as are within their scope.
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Stores launch tubes and vehicles equipped with stores launch tubes are disclosed. According to a particular illustrative example, a stores launch tube includes a tube member and a flexible seal. The flexible seal couples an exterior of the tube member to a hull. The flexible seal acts as a pressure barrier against an ambient environment.
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TECHNICAL FIELD
The present invention relates to aircraft landing systems, and more particularly to a method and apparatus for directing an aircraft along a predetermined trajectory terminating at a desired landing area.
BACKGROUND OF THE INVENTION
Landing an aircraft requires intense concentration to establish proper coordination of the aircraft controls. One of the most important aspects of landing an aircraft is to ensure that the aircraft is properly aligned with the landing area. This typically involves two separate activities. One activity is to assure that the aircraft is landing over the centerline of the landing area. The other activity is to assure that the aircraft is approaching the landing area at the proper speed and vertical descent angle to prevent stalling the aircraft while still landing at a low velocity.
When the landing area is in sight, an aircraft pilot can generally use visual cues to align the aircraft along the centerline of the landing area and at the right descent angle. Although landing an aircraft visually in daylight is difficult, it is even more difficult at night, when the pilot has fewer visual cues available.
A pilot landing an aircraft at a landing field having conventional visual aids typically flies into a glideslope pattern and follows the glideslope while attempting to maneuver over the centerline extension of the landing area. When a pilot is maneuvering into the glideslope pattern from the side of the landing area, it is somewhat difficult to coordinate the turns so that the aircraft is approximately aligned with the centerline extension when the aircraft intercepts the glideslope. Accordingly, it is desirable to have a method and apparatus for landing an aircraft at a landing area which gives highly accurate cues to the position of an aircraft relative to the landing area's centerline and/or desired glideslope.
One particularly severe landing task is landing an aircraft on a carrier, especially aligning the aircraft with the carrier's landing area centerline. Smaller aircraft landing on carriers must be within twenty feet of the centerline, while the margin is ten feet for aircraft with greater wingspans. Complicating the task of landing an aircraft on a carrier is the fact that modern carriers have a landing deck angled 10 degrees from the ship's centerline. Due to the carrier's motion through the water, the ship's centerline typically moves to the right at about 10 knots.
During the day there are many visual cues that the pilot can use when landing on a carrier. However, during the night the visual cues are largely missing. Only the angled deck is lighted. Nighttime loss of depth perception further increases the pilot's difficulties.
Even on the largest carriers, the angled deck measures only 786 feet by 100 feet. The actual landing area is 120 feet long along the deck by 40 feet wide across the deck. The landing area includes four arresting wires spaced 40 feet apart. Thus, if the pilot is 20 feet above the optimum glideslope, the aircraft will miss the arresting wires and have to make a touch-and-go. If the pilot is 20 feet below the optimum glideslope, the aircraft will crash into the stern end of the carrier.
A landing aircraft approaches a carrier at speeds between 105 and 135 knots. Due to these high approach speeds, high momentum, and relatively slow control response of jet aircraft in the landing configuration, it is possible for a small initial drift of the aircraft from the centerline and glideslope to become a serious and potentially dangerous misalignment to the arresting cables and landing area.
Visual aids have been developed to assist in landing aircraft, especially at night. Other than lighting systems that highlight the outline and centerline of the landing area, these visual systems have been developed to assist in the vertical descent guidance of the aircraft. There are no presently-installed precision centerline systems. The visual aids known in the prior art all require the pilot to exercise judgement, such as attempting to fly over a row of lights designating the centerline extension of the runway or keeping lights designating the runway's outline symmetric.
At present there are two primary vertical guidance systems. These systems are Visual Approach Slope Indicator (VASI) and Precision Approach Path Lighting (PAPI). Both of these systems use sets of red and white lights, placed to the side of the runway, which give patterns indicative of the aircraft's placement relative to the desired glideslope. The VASI system includes two sets of red and white lights, one set placed behind the other relative to the approach direction of an aircraft and to the left of the runway as seen from the landing aircraft. Both sets of lights produce adjacent angularly displaced red and white beams directed toward the landing aircraft. In both sets of lights, the upper segment is colored white and the lower segment is colored red. The elevation angles of the two sets of lights are arranged so that when an aircraft is flying on the desired glideslope, the pilot will see the red segment from the farther set of lights and the white segment from the nearer set of lights. If the aircraft is above the desired glideslope, the pilot will see the upper white segments of both sets of lights. If the aircraft is below the desired glideslope, the pilot will see the red segments of both sets of lights.
In the PAPI system, four sets of lights, each having an upper white segment and a lower red segment, as in VASI, are placed side-by-side to the left of the runway as seen by the landing aircraft. The four sets of lights are pointing toward the landing aircraft, but at different elevation angles. The left-hand set of lights has the highest elevation angle and the right-hand set of lights has the lowest elevation angle. The middle two sets of lights are arranged so that a pilot in an aircraft landing along the desired glideslope will see the red light from the two left-hand sets of lights and the white lights from the two right-hand sets of lights. If the aircraft falls below the desired glideslope, the pilot will see the third set of lights from the left turn from white to red, leaving three red lights and one white light. Falling even farther below the desired glideslope will cause all four sets of lights to turn red, indicating danger. On the other hand, if the aircraft rises above the glideslope, the pilot will see one red light and three white lights at first, and then four white lights if it rises sufficiently far.
Two difficulties with such incandescent visual aids, as well as aids using fluorescent or arc lights, are a lack of spatial coherence and a lack of spectral purity. These difficulties cause the transition of an aircraft between a white segment and a red segment to be somewhat muddled, because the lack of spatial coherence causes the boundaries of the two beams to be imprecisely defined. There is a significant period in this transition where the color from such a set of lights appears pink, rather than white or red. In addition, atmospheric scattering removes the shorter wavelength, i.e., bluer, light from the white segments of these sets of lights. This causes the white light itself to appear somewhat pinkish, even before it is mixed with the light produced by the red segment of each set. Accordingly, it is desirable to have visual aids that are not subject to these faults.
Carriers are presently equipped with the Fresnel lens optical landing system (FLOLS). FLOLS is stabilized to account for the carrier's motions and has a maximum range of about 3/4 mile. A pilot using FLOLS sees an amber ball (the "meatball") which is aligned with a row of horizontal green datum lights. When the aircraft is below the desired glideslope, the amber ball appears to be below the datum lights. If the aircraft is somewhat farther below the desired glideslope, the color of the ball changes from amber to red. Below this level, the ball disappears from the bottom of the FLOLS display. While optical glideslope landing systems that are more precise and better stabilized are available, even they are only useful out to a maximum range of 11/4 miles. It is desirable to have visual landing aids with a greater useful maximum range.
One way of overcoming many of the difficulties associated with present-day landing systems (especially on carriers) is to transmit laser light. Laser light has a high spatial coherence and great spectral purity. Because of its high spatial coherence, laser light can produce crisp displays which seem to come from a single point source and are easy to detect by peripheral vision. For example, the "fuzziness" associated with the edge of a laser-based display is only about one inch in width at a range of one mile. In addition, lasers can be used to produce more accurate light corridors (to the limits of diffraction), which have been found to be usable at ranges of at least twelve miles. This overcomes the requirement for a pilot to resolve visual aids before they become useful because the pilot needs only to recognize the colors of the light corridor. Further, laser systems are easy to align and the spectral purity of their light makes them easy to distinguish. Also, lasers presently have life expectancies of from 4,000 to 10,000 hours and produce an average luminous intensity of 500 candela, which provides for very long range acquisition of the laser signals. The laser's monochromaticity gives laser beams high color contrast with the surroundings and makes them easy to identify. Their identification is further enhanced by coherent effects which make the laser seem to have a "texture."
Lasers require only low input power. This, with their collimation, increases the covertness of visual landing aids based on lasers. Since the laser light comes from a virtual point source, small exit apertures and small, lightweight optical elements can be used in laser-based visual landing aids.
SUMMARY OF THE INVENTION
According to one aspect, the invention is a signalling system to aid in directing a vehicle along a predetermined trajectory in a glideslope plane terminating at a desired landing area. The glideslope plane has two sides. A second plane is perpendicular to the glideslope plane and intersects the landing area. The signalling system comprises means for producing beams of laser light having first, second and third distinct colors having temporally constant intensities. The system further comprises three means for directing the laser beams of the distinct colors. The three means for directing the laser beams of the distinct colors are located in a third plane parallel to, but separated from, the second plane. The first means directs the beam of laser light having the first distinct color to one side of the glideslope plane. The second means directs the beam of laser light having the second distinct color along the glideslope plane. The third means directs the beam of laser light having the third distinct color to the other side of the glideslope plane. The system further comprises means for causing the intensity of the directed laser light beams having the three distinct colors to decrease with angular separation from the third plane.
In another aspect, the invention is a signalling system to aid in landing a vehicle at a predetermined landing area along a predetermined straight line trajectory. The trajectory is defined by a predetermined glideslope plane having two sides and a centerline plane having two sides and intersecting the glideslope plane. The signalling system comprises a glideslope plane indication system and a centerline indication system. The glideslope plane indication system includes means for producing beams of laser light having first, second and third distinct colors having temporally constant intensities. The glideslope plane indication system further includes first, second and third means for respectively directing the first, second and third colors to one side, along, and to the other side of, the glideslope plane. The first, second and third means are located in a third plane parallel to, but separated from, a second plane which is perpendicular to the glideslope plane. The second means is located in a third plane which is parallel to, but separated from, the second plane.
The centerline indication system includes means for producing beams of laser light having the first, second and third distinct colors having temporally constant intensities. The centerline indication system further includes first, second and third means for respectively directing the beam of laser light having the first, second and third distinct colors to one side of, along and to the other side of the centerline plane. The first, second and third means are located substantially in the centerline plane. The signalling system further comprises means for causing the intensity of the directed laser light beams to decrease with angular separation from the centerline plane. This causes the intensity of the laser light beams at the vehicle to decrease as the vehicle approaches the landing area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of one aspect of the invention.
FIG. 2 is a perspective view of a first embodiment of another aspect of the invention.
FIG. 3 is a block diagram of a further aspect of the invention.
FIG. 4 is a cutaway perspective view of a still further aspect of the invention.
FIG. 5 is a perspective view of a first embodiment of the laser light source of the present invention.
FIG. 6 is a perspective view of a second embodiment of the laser light source of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view of a first embodiment of one aspect of the invention. An aircraft carrier 10 includes a landing deck 12 which extends between the bow 14 and the stern 16 of the carrier 10. A carrier hull centerline 18 also passes between the bow 14 and the stern 16. The landing deck 12 includes an angled portion 20 having a separate angled centerline 22 which extends forward from the stern 16 and to the left of the hull centerline 18 at an angle of approximately ten degrees. The carrier 10 is typically moving forward into the local wind when aircraft are taking off and landing on the landing deck 12. Aircraft which are approaching to land on the carrier 10 attempt to land in a landing area 24 located on the landing deck 12 along the angled centerline 22. These aircraft approach the carrier 10 from its stern 16. A number of arresting wires 26 are placed transversely across the landing area 24 in order to engage the arresting gear on the aircraft. The arresting wires 26 bring the aircraft to a rapid stop. After it has been stopped, the aircraft is detached from the arresting wires 26 and moved away from the landing area 24 so that the landing area 24 will be ready for any further aircraft which are preparing to land in the landing area 24.
The carrier 10 in FIG. 1 is shown with two glideslope visual aids. One, the Fresnel lens optical landing system (FLOLS), is implemented with a Fresnel lens display 28 which is located adjacent and to the port side of the landing area 24. The Fresnel lens display 28 produces a display which shows the "meatball" configuration that carrier aircraft pilots use. In effect, FLOLS defines an angular corridor 30 which fans aftward from the Fresnel lens display 28. The corridor 30 is oriented at an elevation angle of approximately 3 to 41/2 degrees (depending on sea state) and is centered about a glideslope plane 31 with respect to the landing deck 12. A second plane 33 is perpendicular to the glideslope plane 31 and passes through the landing area 24. The Fresnel lens display 28 is placed in a third plane 35, which is parallel to, but to the left of, the second plane 33. If an aircraft flies out of the corridor 30 in an upward direction, FLOLS does not produce a significant display. If, however, the aircraft flies out of the corridor 30 in a downward direction, FLOLS provides a visual indication in the form of the "meatball" changing color from amber to red.
The second glideslope visual aid shown on the carrier 10 in FIG. 1 is one aspect of the present invention. The second glideslope visual aid includes a laser beam transmitter 32 located to the right of the landing area 24. The laser beam transmitter 32 is located in a plane 37, which is parallel to, but separated from, the second plane 33. Placing the laser beam transmitter 32 on the opposite side of the landing area 24 from the Fresnel lens display 28 reduces pilot confusion about the identities of the two glideslope visual aids. The laser beams 38 transmitted by the laser beam transmitter 32 project aftward. The laser beam transmitter 32 projects its laser beams 38 in such a way that it defines an array of laser light corridors 39 that is angularly symmetric with respect to the glideslope plane 31. The laser beams projected by the laser beam transmitter 32 extend out to a distance of at least twelve nautical miles. It is possible to provide a baffle in the proximity of the laser beam transmitter 32 to effectively block out the laser beams projected by the laser beam transmitter 32 over the landing deck 24 out to distances of 1/2 mile. However, a pilot of an aircraft landing at the landing area 24 will not be confused by the presence of the two visual aids since their display 28 and transmitter 32 are located on opposite sides of the landing area 24.
As will be discussed subsequently, the laser beams projected by the laser beam transmitter 32 contain patterns of laser light colors and blinking patterns which identify the angular location of the aircraft with respect to the glideslope plane 31.
FIG. 2 is a perspective view of a first embodiment of another aspect of the invention. This aspect of the invention is a centerline localizer system. The centerline localizer system includes a laser beam transmitter 40 located at the stern 16 of the carrier 10, along or just below the angled centerline 22, on a centerline plane 42. The centerline plane 42 is perpendicular to the landing deck 12 and passes through the angled centerline 22. As will be disclosed subsequently, the laser beam transmitter 40 produces an array of fan beams 41 which are projected aftwardly from the stern 16 symmetrically with respect to the centerline plane 42. The fan beams 41 can be seen at distances at least as great as twelve nautical miles. The location of the laser beam transmitter 40 is sufficiently different from the locations of the display 28 and the laser beam transmitter 32 so that a pilot of an aircraft approaching the landing area 24 from the stern 16 of the carrier 10 will easily be able to distinguish the three transmitters on the basis of their relative locations.
FIG. 3 is a block diagram of a further aspect of the invention. This aspect of the invention produces, directs, and shapes the laser beams that are projected by the display 28 and the laser beam transmitter 32. This aspect includes a laser light source 50 which includes three lasers respectively capable of producing steady beams of red, amber (or yellow) and green laser light. In one possible embodiment, the red and amber laser light beams are produced by helium neon lasers respectively operating at wavelengths of 633 and 594 nanometers, although other operating wavelengths could be chosen. The green light is produced by an argon laser operating at a 514 nanometer wavelength. Other lasers, such as solid state lasers, could be chosen to produce the lower light beams. The average radiant intensity projected into the beams by the red, amber and green lasers is approximately 1, 0.3 and 0.5 mW per square degree, respectively. Accordingly, the average luminous intensity of the lasers is approximately 500 candelas.
The laser light source 50 is connected to means 52 for directing the beams, through a transmitting channel, such as fiber optic cables or a path through the atmosphere. The beam directing means 52 separately transmits each of the three colored beams to beam shaping and filtering optics 54. In the case of the red and green laser beams, the beam directing means 52 transmits the beams through intermittences generators 56. In one embodiment, the intermittences generators 56 produce slow and fast intermittently interrupted beams. The beams can be transmitted between the various connected means through atmospheric channels or fiber optic channels. In addition, this aspect of the invention also includes an ambient light sensor 58 which senses the amount of ambient light in the vicinity of the beam shaping and filtering optics 54 and produces a control signal which it transmits to the beam shaping and filtering optics 54 laser light source 50 through a cable 58. The beam shaping and filtering optics 54 include apertures, telescopic optics, cylindrical lenses, collimating lenses and telescope defocus optics to produce desired fan-shaped patterns. The beam shaping and filtering optics 54 can also include filters responsive to the control signal on the cable 58. The intermittences are produced by mechanical choppers, such as the solenoid-activated shutters produced by NM Lasers. The solenoids in the shutters are driven by electronics which produce 12 volt pulses having a 35 percent duty cycle. Alternatively, the intermittences can be produced by rotating blades, scanning mirrors, or rotating mirrors.
FIG. 4 is a cutaway perspective view of a still further aspect of the invention. In this embodiment, an enclosure 60 has one side with a horizontal array of circular apertures 62. The enclosure 60 also contains an equal number of sources of laser light, such as small gas lasers 64, which are aligned with the apertures 62. Each laser 64 produces a beam 65 of laser light which is directed toward the apertures 62. The light leaving each of the lasers 62 is spatially coherent and collimated. This light passes through a series of optical elements, including a beam shaping aperture, a cylindrical lens and a collimating lens as will be explained subsequently. The beam may also pass through a mechanical chopper or a neutral density filter. The lasers 64 are typically angularly displaced from one another, so that the laser light beams 65 are slightly divergent.
FIG. 5 is a perspective view of a first embodiment of the laser light source of the present invention. The enclosure 60 shown in FIG. 4 typically contains several copies of the laser light source shown in FIG. 5. The laser light beam 65 impinges on the beam-forming aperture 66, which can also include a solenoid-activated shutter 68. The aperture 66 forms the shape of the beam of laser light passing through. The aperture is typically rectangular in shape and produces a beam of light that is longer in one direction than it is in the other. The solenoid-activated shutter 68 periodically closes, thereby preventing any light from passing through the aperture 66. The shutter 68 closes at a rate determined by its conventional driving electronics. Typical rates are between 1 and 10 Hertz. When the shutter 68 is open, the expanded laser light beam 65 passes through to the cylindrical lens 74. The cylindrical lens 74 causes the divergence of the beam 72 to be contracted in the plane perpendicular to the cylindrical axis of the cylindrical lens 74, while allowing the light in the orthogonal plane to pass through the cylindrical lens 74 largely unaffected. In the view of FIG. 5, the vertical dimension of the light beam passing through the cylindrical lens 74 is still slightly divergent, while the horizontal dimension of the light beam passing through the cylindrical lens 74 is reduced. the shaped beam of light passing through the cylindrical lens 74 then passes through the collimating lens 76, which may be placed in an aperture 62 (see FIG. 4).
In one embodiment of the aspect of the invention shown in FIG. 4, seven slightly diverging contiguous fan beams (or corridors) of laser light 80 are produced. The central laser 62 a and associated optics can produce a vertically-oriented fan beam of steady amber laser light. The fan beam of amber laser light is 5 degrees high in the vertical plane and between 0.2 and 0.4 degrees wide in the horizontal plane. The beam produced by the laser 64 a is not interrupted by a shutter, so it is steady. The laser 64 sr produces a vertically-oriented fan beam of steady red laser . The fan beam of the red laser light is 5 degrees high in the vertical plane and has a horizontal angle of 0.8 degrees. The laser 64 br also produces a vertically-oriented beam of red laser light, but this beam is interrupted by a chopper at a slow rate, approximately 50 pulses per minute. The laser 64 fr also produces a beam of red light, but this beam is interrupted by a chopper at a fast rate, between 3 and 5 Hertz. The laser 64 sg produces a beam of green light which generates a fan beam of steady green light when it exits through its corresponding aperture 62. The laser 64 bg produces a green beam which is interrupted at the same slow rate as the beam 64 br . The laser 64 fg produces a green beam which is interrupted at the same fast rate as the laser 64 fr .
The aspect of the invention shown in FIG. 4 can be placed on the centerline plane 42 of a carrier 10 (see FIG. 1) so that the center of the fan beam 80 produced by the laser 64 a is aligned with the centerline plane 42. This will produce a centerline indicator system, where the centerline plane 42 is indicated to the pilot of an aircraft by a steady amber light. If the aircraft moves slightly to the right of the amber section as it approaches the carrier, it will first enter a fan beam of steady green light. As it continues to the right, the aircraft will next enter a fan beam of a slowly-blinking green light. Even further beyond the fan beam of slowly-blinking green light is a fan beam of quickly-blinking green light. To the left of the amber fan beam, the same pattern of interrupted fan beams is produced, except that they are red. These colors comply with the standard code used in navigation, where green means starboard and red means port.
A more compact and better protected piece of visual landing aid equipment can be built using the component shown in FIG. 6. FIG. 6 is a perspective view of a second embodiment of the laser light source of the present invention. In this case, an optical fiber 80 conducts laser light from a source of a particular color of laser light to the end of the optical fiber 80. The light emitting from the optical fiber 80 impinges on the expansion lens 69, which causes it to diverge as it passes toward the cylindrical lens 86. This apertured light beam then passes to a cylindrical lens 86 (which has its cylindrical axis horizontal) to produce a horizontally oriented fan beam from the output of the expander lens 69. The light from the cylindrical lens 86 is shaped into a rectangular beam whose horizontal dimension is greater than its vertical dimension by the mask 88. The light then passes through collimating lens 89. In some cases the light beam passing through the mask 88 passes through a linear-tapered neutral density filter 90 before it reaches the expander lens 89. The apparatus shown in FIG. 6 can be stacked vertically to produce a glideslope indicator system, where the central beam is a steady amber, the fan beams adjoining the central beam above and below are steady green and steady red, and the beams adjoining the respective steady green and steady red beams are blinking green and blinking red beams. The blinking beams can be created by interrupting the laser beams produced by the laser light sources before the light is introduced to the fiber optic 80.
Those skilled in the art will recognize that various modifications of the method and apparatus of the present invention can be made without departing from the spirit and scope of the invention. The scope of the invention is to be determined only by the following claims. In particular, the method and apparatus of the present invention can be applied to situations other than landing an aircraft, for example, maneuvering a craft in space.
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A method and apparatus for aiding a landing aircraft. Three differently-colored beams of laser light are produced and transmitted, one of the beams of laser light being transmitted in a plane containing the direction from which the aircraft is approaching. Another of the beams of light is transmitted on one side of the plane, and the third of the beams of light is transmit on the other side of the plane. The pilot of the aircraft can determine whether the aircraft is on the plane or to the one side or the other by the color of the light the pilot receives. If desired, at least one of the colored laser beams that is transmitted toward one side of the plane can be broken into a plurality of adjacent fan-shaped beams, the light in at least one of the fan-shaped beams being interrupted intermittently.
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FIELD OF THE INVENTION
This invention relates to a scraping tool and particularly to a scraping tool for removing creosote from the walls of a chimney flue.
BACKGROUND OF THE INVENTION
For reasons of safety and efficiency, chimney flues should be cleaned and scraped regularly to remove creosote deposits. Creosote is a crusty black layer that builds up in the flue as hot, unburned gases and tar-like liquids go up the flue with the smoke from a stove or fireplace fire. As these substances contact cooler surfaces they condense, leaving behind a creosote deposit that builds up fire after fire; the deposits are most heavy at the cooler areas of the chimney, particularly at the top and in the throat area. This creosote build-up acts like an insulator, reducing heat transfer efficiency. Large deposits can even block the flue. Creosote is highly flammable and is a significant cause of house fires. As a general rule, heavily used fireplaces should be cleaned yearly. If a modern, airtight stove has been installed in the fireplace, cleaning should occur more frequently.
At present, creosote is removed from a chimney flue primarily by the use of wire brushes. For cleaning the chimney flue liner, the brushes are raised and lowered within the flue by means of ropes or poles. At the throat area of the flue, wire brushes may be inserted into the flue from below. Another device employs rods of fiberglass or the like which can be connected end to end for lowering a wire brush into the flue. However, it has been found that, while these wire brushes are effective in removing some of the creosote deposit, they do not readily permit sufficient force to be applied to the chimney flue walls to enable removal of heavy creosote deposits. Therefore, it is desirable that a tool be provided that will facilitate removal of heavy creosote deposits from the flue by enabling the user to apply greater force to the chimney wall from various directions in a more sustained manner than has been possible with heretofore-available devices.
OBJECTS OF THE INVENTION
Therefore, it is an object of my invention to provide a scraping tool that will facilitate removal of creosote deposits from a chimney flue.
It is a further object of my invention to provide a scraping tool that will permit use of sufficient efficiently-directed force against the chimney walls to permit removal of heavy creosote deposits.
It is a still further object of my invention to provide a scraping tool that is readily maneuverable within the chimney flue so that the scraping force may be applied to the walls from various angles as desired.
It is another object of my invention to provide a scraping tool whose scraping edges are adjustable in position relative to the handle so as to provide maximum versatility.
It is a still another object of my invention to provide a scraping tool that may be readily assembled and disassembled in different forms so as to permit the scraping tool to be used both from above the chimney into the flue, and from the fireplace through the throat area of the flue, with maximum efficiency.
SUMMARY OF THE INVENTION
The objects set forth above are satisfied by the scraping tool of my invention, which comprises scraping means adjustably and removably securable to an elongated, rigid handle, said scraping means comprising two rigid metal blades each having a scraping edge, and securing means enabling either one or both blades to be attached to the handle and further enabling the position and distance of each blade edge relative to the handle to be selectively adjusted when both blades are attached to the handle. Preferably, the handle is provided with interconnection means for connecting additional lengths of handle material so that the length of the handle may be increased as desired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustrative sectional view of a typical domestic fireplace, including a firebox, flue and chimney.
FIG. 2 is a plan view, partly in section, of a scraping tool according to the preferred embodiment of my invention.
FIG. 3 is an illustrative perspective view of the use of the scraping tool of FIG. 2, wherein said tool is introduced into the chimney flue from the top of the chimney.
FIG. 4 is an exploded view of the scraping tool of FIG. 2.
FIG. 5 is an exploded view of the scraping tool of my invention wherein the securing means have been modified to permit a further range of adjustment of the scraping edges relative to the handle.
FIG. 6 is a plan view of the scraping tool of FIG. 5.
FIG. 7 is an exploded view of the scraping tool of my invention, wherein a single blade is attached to the handle.
FIG. 8 is a plan view of the scraping tool of FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
There is depicted in FIG. 1 a typical fireplace 10, chimney 12 and flue 14. Flue 14 is typically lined with a ceramic flue liner 16. Chimney 12 extends approximately from smoke chamber 18 to concrete cap 20. Creosote builds up heavily on the flue liner 14, particularly in the region near the top of the chimney flue, and in the throat area 24, just above firebox 22.
Turning to FIGS. 2 and 4, there is depicted a scraping tool 30 according to the preferred embodiment of my invention. Two blades 50 and 60 include scraping edges 52 and 62 respectively, spaced apart from each other and located on either side of handle 34. Blades 50 and 60 are each preferably comprised of two flat pieces of one-quarter inch steel welded together in the shape of an elongated "T", but with the head 51, 61 of each "T" meeting the leg 53, 63 at an angle of approximately 60 degrees on the side of the leg farthest from the respective cutting edge. The head and the leg of each "T" are preferably welded together by a low hydrogen technique. The heads 51, 61 of blades 50, 60 are preferably of forged, hardened steel. Scraping edges 52 and 62 are formed at an angle of approximately 45° along one side of the head 51, 61 of each "T". As seen in FIG. 4, blades 50 and 60 include slots 54 and 64, respectively, formed in the leg portion 53, 63 of blades 50 and 60, which slots permit adjustment of the position of the blades as further explained below. In the particular embodiment here described, the length of the scraping edge of each blade is approximately four inches.
Blades 50 and 60 are secured to handle 34 by securing means including coupling 36, washers 37, thread rod 38, nut 39, bolts 42, lock washers 43, nuts 44 and cross-bar 40. Handle 34 preferably comprises an approximately four-foot long section of 3/8-inch iron pipe threaded at both ends. At the end to which the securing means and blades are attached, coupling 36, preferably made of iron, is screwed onto handle 34. Coupling 36 is threaded at one end to receive handle 34, and at the other end to receive a length of thread rod 38 which projects out of coupling 36. Thread rod 38 is secured in place by nut 39 and washers 37, nut 39 being tightened down on coupling 36 so that thread rod 38 extends outward from and along the axis of the handle as shown in FIGS. 2 and 4.
Cross-bar 40 is preferably fabricated of one-quarter inch steel, formed in the shape of an elongated, right-angle "U". Cross-bar 40 is provided with five holes 48 in the base of the "U", the middle hole 48 receiving thread rod 38. A lock washer 43 and nut 44 are placed on thread rod 38 projecting through middle hole 48 and are tightened down to secure cross-bar 40 to handle 34. Bolts 42 are then passed through the remaining four holes 48 of cross-bar 40 and are secured in place by lock washers 43 and nuts 44. Blades 50 and 60 may then be placed on cross-bar 40 so that the leg portions 53, 63 of the blades rest on the top of the "U" of cross-bar 40, with bolts 42 projecting through slots 54 and 64. The positions of blades 50 and 60 may be adjusted by sliding blades 50 and 60 toward or away from the axis of handle 34 (see the dotted lines in FIG. 2). After the blades have been positioned in the desired location, the blades may be secured to cross-bar 40 by securing nuts 44 and lock-washers 43 to bolts 42. In the preferred embodiment here depicted, the spacing between the blade edges may be adjusted from approximately 101/2 inches to about 145/8 inches.
Turning to FIG. 3, there is illustrated the use of the scraping tool of the instant invention to remove creosote from a chimney flue, introducing the scraping tool from the top of the chimney. Blades 50 and 60 have preferably been adjusted in position so that the distance separating scraping edges 52 and 62 is approximately equal to the distance between the flue walls being scraped. The cross-sectional dimension of a typical fireplace flue is approximately 103/8 inches×63/8 inches. The scraping tool of the instant invention is preferably adjusted first for one dimension of the flue, and then for the other. These adjustments may be made rapidly by the user simply by loosening nuts 44 that hold blades 50 and 60 in place, adjusting the position of blades 50 and 60, and then re-tightening nuts 44 on bolts 42. The scraping tool of my invention allows the user to maneuver scraping edges 52 and 62 into various angles with the flue walls, so that, by stroking up and down while moving the handle to one side or another, the maximum leverage and the most efficient scraping angle may be utilized. The scraping tool of my invention is particularly useful in connection with straight-drop chimneys that include a ceramic liner, for example of terra-cotta. It is not recommended that my scraping tool be used in irregular or offset chimneys.
In FIG. 3, chimney sweep 99 can be seen to be holding a further section of handle 34' ready to be attached at one end to handle 34 by means of connector 32 (see FIG. 4), which connector is preferably made of steel and is internally threaded at both ends. Another connector 32 at the other end of section 34' will permit connection of another section of handle, and so forth. Each section of handle is approximately four feet long, although other lengths may obviously be utilized with satisfactory results.
FIG. 5 depicts an alternative arrangement of the scraping tool of my invention, wherein blades 50 and 60 are attached directly to handle 34 by means of coupling 36, washers 37, thread rod 38, nut 39, lock-washer 43, nut 44 and washers 46. Cross-bar 40 (of FIGS. 2 and 4) is not utilized. Blades 50 and 60 may be adjusted on handle 34 as shown by the dotted lines in FIG. 6. This particular arrangement is useful when the dimensions of the chimney flue are such that the arrangement of FIG. 2 cannot be accommodated. By this arrangement, in the particular embodiment here shown, the distance between the scraping edges may be adjusted from about 6 inches to 85/8 inches.
In FIGS. 7 and 8 there is shown another arrangement of the scraping tool of this invention, wherein only one blade 50 is secured to handle 34 by means of L-shaped bracket 70. Bracket 70 is preferably fabricated of 3/16 inch steel, and includes three holes 71, 72, 73 as shown. Washer 46 is placed over thread rod 38 extending from coupling 36, and thread rod 38 is then placed through hole 71, nut 39 and washer 46 then securing bracket 70 to thread rod 38. Bolts 42 are then placed through holes 72 and 73, and slot 54 of blade 50 is placed over the bolts 42 so that the leg 53 of blade 50 rests on bracket 70. Lock-washers 43 and nuts 44 are tightened on bolts 42 to secure blade 50 to bracket 70, as shown in FIG. 8.
The one-blade arrangement of FIGS. 7 and 8 is particularly useful in removing creosote from the throat area of the flue, since it can be readily maneuvered in small spaces, and yet provides good leverage and scraping power to the user.
Thus the scraping tool of my invention provides the user with several alternative arrangements so that the maximum scraping efficiency can be achieved. The tool may be re-arranged easily and quickly, thereby facilitating the work of the user, and resulting in a faster and more thorough cleaning of the chimney flue.
It will be readily appreciated by those skilled in the art that the present invention in its broader aspects is not limited to the specific embodiments herein shown and described. Accordingly, variations may be made from the embodiments described herein which are within the scope of the accompanying claims, without departing from the principles of the invention and without sacrificing its chief advantages.
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A scraping tool comprising scraping means adjustably and removably securable to an elongated, rigid handle, the scraping means comprising two rigid metal blades each having a scraping edge, and securing means for attaching one or both blades to the handle as desired, the securing means further enabling the position and distance of each blade edge relative to the handle to be selectively adjusted when both blades are attached to the handle. Preferably, the handle is provided with interconnection means for connecting additional lengths of handle so that the total length of the handle may be increased as desired.
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STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH
This invention was made with Government support under Contract #N00014-07-C-1103, and the Government has certain rights in the invention.
FIELD OF THE INVENTION
The present invention relates to underwater projectiles.
BACKGROUND OF THE INVENTION
Underwater gun systems are being developed for naval warfare. These systems often use an energetic propellant to launch a projectile from a launch tube. A challenge to the development of effective underwater guns is that a projectile traveling through water experiences a resistance or drag that is approximately one thousand times greater than the resistance experienced by the projectile traveling through air. As a consequence of this high level of drag, conventional underwater projectiles are limited to speeds of no more than about 80 kilometers/hour (km/h).
The high resistance presented by the water medium can be addressed via a phenomenon known as “supercavitation.” This phenomenon can occur when a projectile having a blunt nose travels at sufficiently high speeds under water. The blunt nose pushes aside water as the projectile advances. When the hydrodynamic pressure of water that is pushed aside overcomes the ambient static pressure, water vaporizes. The vaporized water forms air bubbles, which coalesce to form a “cavity” in the water. If enough bubbles are formed, the cavity will be large enough to completely engulf the projectile, with the exception of the blunt tip of the nose. This characterizes the supercavitating mode of operation, which is also referred to as “cavity-running” operation).
Within the vaporous cavity, the projectile is effectively traveling through air rather than water. The projectile, therefore, experiences greatly reduced drag. As a consequence, the projectile is capable of attaining a velocity far in excess of what is possible when traveling through water proper.
Supercavitating projectiles often collide with the walls of the enveloping cavity, which increases drag. This can be addressed by equipping the projectile with fins. When a fin contacts the cavity wall, a torque develops that steers the projectile toward the center of the cavity into a region of lower drag.
The fins are usually located in the aft section of the projectile body and project radially outward therefrom. The radially-extending fins prevent the projectile from being tightly packaged within a launch tube. This drawback is addressed by coupling the projectile to a sabot, which is a carrier that centers the projectile within the launch tube and falls off after launch. Use of a sabot disadvantageously increases the amount of energetic propellant required for launch and also requires an increase in launcher size. A need therefore exists for an improved supercavitating projectile that retains the in-cavity stability of known fin designs but does not require a sabot for launch.
SUMMARY OF THE INVENTION
Some embodiments of the present invention provide an improved design for an underwater projectile that is capable of operating in a supercavitating mode.
In accordance with the illustrative embodiment, a fin is pivotally coupled to the cylindrical body of the projectile. This pivotal coupling enables the fin to either (1) stow itself within a recess at the surface of the projectile or (2) deploy to a radially-extended position.
When stowed, substantially no portion of the fin protrudes beyond the circumference of the body of the projectile. In this stowed state, the projectile can be packaged inside of a launch tube or barrel without the use of a sabot. Furthermore, the fin is disposed forward of the aft end of the projectile of the booster base of the projectile. This enables multiple such projectiles to be “stacked” nose to tail within a barrel, such as in a stacked launcher configuration disclosed in U.S. Published Patent Application 2008/0022879, which is incorporated by reference herein. In this fashion, the projectile can be launched using an energetic propellant disposed within the launch tube (as per the referenced published patent application) or within the projectile.
Upon launch, the projectile enters the water and travels through it until a vaporous cavity is formed. In some embodiments, the water drag experienced by the projectile immediately following launch causes the fins to pivot to the deployed position. In some other embodiments, deployment via water drag is supplemented by a spring-biasing element that is used to initiate pivoting of the fins.
Once deployed, the fins operate in substantially the same manner as fixed-fin designs known in the prior art. In particular, the fins function as a control surface, interacting with the wall of the cavity in which the projectile travels. Contact with the cavity wall imparts sufficient torque to urge the projectile back toward the center of the cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A depicts a perspective view of a projectile in accordance with the illustrative embodiment of the present invention, wherein deployable fins of the projectile are in a stowed state.
FIG. 1B depicts a front end view of the projectile of FIG. 1A .
FIG. 2A depicts the projectile of FIG. 1A wherein the fins are in a deployed state.
FIG. 2B depicts a front end view of the projectile as shown in FIG. 1A .
FIG. 3A depicts a front perspective view of one of the deployable fins.
FIG. 3B depicts a back perspective view of one of the deployable fins.
FIG. 4 depicts an exploded view of the aft end of the projectile of FIG. 1A .
FIG. 5A depicts a side cross-sectional view of the aft end of the projectile of FIG. 1A , wherein the fin is shown in a stowed state.
FIG. 5B depicts a side cross-sectional view of the aft end of the projectile of FIG. 2A , wherein the fin is shown in a deployed state.
FIG. 6 depicts a perspective view of the aft end of the projectile of FIG. 2A , wherein the fins are shown in a deployed state.
FIG. 7 depicts a side view of a launcher container a plurality of the projectiles disclosed herein, wherein the projectiles are disposed in a stacked launcher configuration.
DETAILED DESCRIPTION
The following terms are defined for use in the description and the appended claims as follows:
“Chord” or “Chord length” means, in the context of a fin, the distance from the front (or leading edge) of the fin to the back (or trailing edge) of the fin. The chord is parallel to the longitudinal axis of the projectile. “Longitudinal axis” means, in the context of a projectile, an axis aligned with the length (nose to tail) of the projectile. “Major surface” means, in the context of a fin, the (two) surfaces having an area that is a function of the span of the fin and the width of the fin, as the terms “span” and “width” are defined herein. “Projectile” means any artificial body, either powered, such as by a motor, or un-powered, such as a bullet, etc. “Root” means, in the context of a fin, the portion of the fin that is nearest to the body of the projectile when the fin is deployed. “Span” means, in the context of a fin, the distance between the tip and the root of the fin. “Substantially” means, in the context of an angular deviation, ±10 degrees. “Supercavitating projectile” means a projectile that, when moving under water at sufficient speed, is enveloped by a gaseous cavity that the projectile itself generates. “Tip” means, in the context of a fin, the portion of the fin that is furthest from the body of the projectile when the fin is deployed. “Width” means, in the context of a fin, the straight-line distance between opposed edges of a fin, wherein (a) the opposed edges do not include the tip or root of the fin and (b) a line connecting the opposed edges is not parallel to longitudinal axis of the projectile. If the line connecting the opposed edges of the fin were parallel to the longitudinal axis of the projectile, the opposed edges would be the leading and trailing edge of the fin and the distance defined here as “width” would be properly characterized as the “chord” or “chord length” of the fin.
Definitions of other terms and phrases may appear elsewhere in this disclosure.
FIG. 1A depicts a perspective view of supercavitating projectile 100 in accordance with the illustrative embodiment. Projectile 100 comprises nose 102 , body 108 , fin recess 110 , and fin 112 , interrelated as shown.
Blunt forward end 104 of nose 102 is used to create the vaporous cavity that encompasses projectile 100 during supercavitating operation, in known fashion. For that reason, in the context of a supercavitating projectile, the forward end of the nose is typically referred to as a “cavitator.” In the illustrative embodiment, cavitator 104 is flat; however, in other embodiments, other structural arrangements for the cavitator may suitably be used. See, for example, U.S. patent application Ser. Nos. 12/102,784 and 12/102,781, incorporated by reference herein.
In the illustrative embodiment, nose 102 has “stepped” profile 106 . The stepped profile results from configuring at least the forward portion of nose 102 as a plurality of substantially right-circular cylindrical shells or segments that increase in diameter progressively moving aft. The stepped profile of the nose can provide certain advantages as a function of the projectile's yaw angle. Other structural arrangements for the nose may suitably be used. See, for example, U.S. patent application Ser. Nos. 12/102,784 and 12/102,781.
Body 108 is substantially cylindrical in shape. In some embodiments, body 108 houses a propellant bay (not depicted). The propellant bay contains a chemical propellant, typically (e.g., ammonium perchlorate, etc.) that is ignited to generate the energy for launch. The aft end of body 108 includes plural recesses 110 for accommodating a plurality of fins 112 . In the illustrative embodiment, projectile 100 has three fins 112 .
In FIG. 1A , fins 112 lie in-plane with the exterior of body 108 , substantially parallel to longitudinal axis A-A and substantially flat against projectile 100 in recesses 110 . This orientation defines the “stowed” position or state of fins 112 . FIG. 1B is a front end view of projectile 100 . As seen from FIG. 1B , when fins 112 are in their stowed position, they do not project beyond the circumference of body 108 .
FIGS. 2A and 2B depict projectile 100 with fins 112 rotated out-of-plane from the surface of body 108 and away from the recess 110 . This defines the “deployed” position or state of fins 112 . As depicted in the front end view of FIG. 2B , fins 112 project beyond the circumference of body 108 when they are in the deployed state.
FIGS. 3A and 3B depict, via respective front and rear perspective views, further details of fin 112 . Referring now to both drawings, fin 112 comprises body portion 313 and shoulders 318 A and 318 B, interrelated as shown.
Body portion 313 of the fin 112 has two major surfaces; front surface 314 and rear surface 316 . In the embodiment depicted in FIGS. 3A and 3B , front surface 314 has a concave shape and rear surface 316 has a convex shape. Note that in FIGS. 2A , 3 A, and 6 , front surface 314 is depicted as having a concave shape. In other embodiments, front surface 314 is flat, so as to mate flush with recess 110 (see, e.g., FIG. 5A , etc.). Regardless of the shape of front surface 314 , rear surface 316 maintains its curved shape to smoothly integrate with the exterior of body 108 .
Body portion 313 is characterized by tip T, root R, span S, and width W. The distance characterized as “width W” would properly be termed the “chord” of fin 112 if the fin were oriented in the manner of a typical fin, wherein the edges E 1 and E 2 were accurately characterized as the leading edge and trailing edge of the fin. But as depicted in FIG. 2A , for example, edges E 1 and E 2 of the fin are offset by ninety degrees relative to a typical projectile fin. Normally, fin orientation is a function of aerodynamics; fins would not be oriented so as to present a major surface to “on-coming” fluid. Rather, a major surface would be oriented parallel to the direction of movement (of the fluid or projectile) to avoid what would otherwise be a large drag force. In the accordance with the illustrative embodiment, however, fin orientation is a function of the deployment mechanism; aerodynamics are not of particular concern. In fact, from the perspective of aerodynamics, the fins 112 have the worst possible orientation, in the sense that the ratio of the width of fin 112 to the chord of fin 112 is greater than 1. Note that due to the way in which fins 112 are oriented, the dimension that is referred to as the chord of fin 112 would, in a typical fin orientation, be the thickness of fin 112 . And, as previously noted, the dimension that is referred to as the width of fin 112 would, in a typical fin orientation, be the chord of fin 112 .
Portion 315 of front surface 314 near tip T is tapered wherein the thickness of body portion 313 decreases to a minimum at tip T. In some embodiments, a portion of rear surface 316 near tip T is tapered as well (see, e.g., FIGS. 5A and 5B ). Root R of body portion 313 is curved. In the illustrative embodiment, this curve precisely matches the curved shape of body 108 . As described in further detail later in this specification, the matching curved surfaces of root R and body 108 functions to support fins 112 when they are in the deployed state.
Shoulders 318 A and 318 B depend from root R of body portion 313 . The shoulders are separated by space 320 . Extending away from root R of body portion 313 , shoulders 318 A and 318 B enlarge to accommodate respective pivot-pin receiving holes 322 A and 322 B.
Edge 319 of shoulders 318 A and 318 B is a contoured surface that defines a cam, as discussed later in this specification in conjunction with FIGS. 5A and 5B . Viewed from the front of fin 112 (i.e., as in FIG. 3A ), edge 319 defines a smooth curve until region 324 , wherein edge 319 juts abruptly inward defining wall 326 . Edge 319 then continues at an angle (typically, but not necessarily, 90 degrees, ±about 20 degrees) relative to wall 326 , defining surface 328 . This surface is substantially parallel to the tangent of the “circle” defined by hole 322 A (or 322 B) at the point at which face 326 would intersect the hole, if face 326 were so projected.
FIG. 4 depicts fin-receiving region 430 disposed at the aft portion of body 108 and further depicts, via an exploded view, the fin assembly, indicated generally at 444 . The fin assembly includes fin 112 , pin 446 , and cam-follower assembly 448 .
Fin-receiving region 430 is physically adapted to receive fin assembly 444 . Specifically, fin-receiving region 430 includes recess 110 , channels 432 A and 432 B, and access hollow 442 .
Recess 110 is dimensioned and arranged to accommodate fin 112 in the stowed state. The recess is sufficiently deep so that when fin 112 is stowed, rear surface 316 of fin body 313 aligns with the surface of body 108 . In the illustrative embodiment, the curvature of rear surface 316 matches that of body 108 to provide a smooth, essentially continuous surface when fin 112 is stowed.
Channels 432 A and 432 B, which align directionally with longitudinal axis A-A of projectile 100 (see, FIG. 1A ), are disposed proximal to and aft of recess 110 . The channels are spaced apart and so define tab 436 . Pivot-pin receiving hole 434 A is disposed in wall 433 A at the forward portion of channel 432 A, which is proximal to aft edge 431 of recess 110 . Similarly, pivot-pin receiving hole 434 B is disposed in wall 433 B at the forward portion of channel 432 B. Pivot-pin receiving hole 438 is disposed in tab 436 proximal to aft edge 431 of recess 110 . Holes 434 A, 434 B, and 438 are axially aligned with one another along axis B-B.
Fin 112 is pivotally coupled to projectile 100 as follows. Shoulders 318 A and 318 B are received by respective channels 432 A and 432 B. Fin 112 and fin-receiving region 430 are dimensioned and arranged so that when the fin's shoulders are received by channels 432 A and 432 B, pivot-pin receiving holes 422 A and 422 B in the shoulders and pivot-pin receiving holes 434 A, 434 B, and 438 in fin-receiving area 430 are axially aligned with one another along axis B-B to collectively receive pivot pin 446 . In this fashion, fin 112 is pivotally coupled to projectile 100 . Access hollow 442 , which in the illustrative embodiment is proximal to hole 434 B, provides access to the pivot-pin receiving holes to insert pivot pin 446 .
With continued reference to FIG. 4 , disposed within channel 432 B is cam follower assembly 448 which, in the illustrative embodiment, comprises leaf spring 450 , locking element 454 , and fastener 458 . In the illustrative embodiment, locking element 454 is a locking wedge and fastener 458 is a set screw. Fastener 458 , which passes through hole 456 in locking element 454 and hole 452 in leaf spring 450 , is ultimately threaded into (or otherwise secured to) the base of the channel. Although cam follower assembly 448 is disposed in channel 432 B in the illustrative embodiment, it is to be understood that the cam follower assembly could alternatively be disposed in channel 432 A. Furthermore, in some embodiments, a cam follower assembly is disposed in both channels 432 A and 432 B. Cam follower assembly 448 and its operation are discussed further below with respect to FIGS. 5A and 5B .
FIGS. 5A and 5B depict a cross-sectional side view through fin-receiving region 430 along the mid-line of channel 432 B and through axis C-C of fin 112 shown in FIG. 4 , but when the fin is actually pivotally coupled to projectile 100 . More specifically, these Figures depict recess 110 and a view into channel 432 B, as well as a cross sectional view of fin body 113 , fin shoulder 318 B, and cam follower assembly 448 .
FIG. 5A depicts fin 112 in a stowed state. In this state, forward surface 314 of the fin abuts the surface of recess 110 and rear surface 316 of fin body 103 is approximately co-planar with the surface of projectile body 108 . Gap G is formed between the surface of recess 110 and tapered portion 315 of fin 112 near tip T thereof.
FIG. 5A also depicts cam follower assembly 448 in channel 432 B. Leaf spring 450 of cam follower assembly 448 is spaced above bottom 560 of channel 432 B, enabling the leaf spring to deflect downward. Fastener 458 is shown in threaded engagement with base 560 of channel 432 B.
FIG. 5B depicts fin 112 in the deployed state. To attain this state from the stowed state depicted in FIG. 5A , fin 112 partially rotates about pivot pin 446 . Rotation of fin 112 from the stowed to the deployed state occurs when projectile 100 contacts water after leaving the barrel from which it is fired or launched. Rotation occurs as a consequence of the drag forces experienced at gap G. In some embodiments, a “spring-biasing” element (not depicted in FIG. 5 b ; see FIG. 6 ) urges fin 112 away from recess 110 to begin its rotation to the deployed state as projectile 100 leaves its launch tube.
In the illustrative embodiment, fin 112 rotates about 135 degrees from the stowed state to the deployed state. At some point during rotation of fin 112 , surface 319 of shoulder 318 B engages leaf spring 450 . As the fin continues to rotate, leaf spring 450 flexes downwardly (toward base 560 ), with maximum flexure occurring as region 324 of cam surface or edge 319 (see also, FIGS. 3A and 3B ) contacts leaf spring 450 . At this point, surface 319 juts inward abruptly, releasing the flex in leaf spring 450 such that the leaf spring forcibly rebounds, engaging flat cam surface 328 .
Once cam surface 328 and leaf spring 450 engage, as depicted in FIG. 5B , fin 112 is effectively prevented from rotating back toward recess 110 . This prevents fin 112 from “chattering” when the projectile is underway.
FIG. 6 depicts a perspective view of the aft end of projectile 100 , showing two of fins 112 in the deployed state. Drag on front surface 314 of fin 112 forces the fin back until root R engages the surface of body 108 . The body of projectile 100 itself therefore supports fins 112 once they deploy.
FIG. 6 depicts optional spring-biasing element 662 , which in the illustrative embodiment is a cupped spring washer or cone washer, also known as a Belleville washer. This non-flat washer has a slight conical shape that gives the washer a spring-like characteristic. As projectile 100 is loaded into its launch tube, fin 112 is forced against spring-biasing element 662 such that the spring-biasing element is compressed. When projectile 100 is fired from its launch tube, spring-biasing element 662 returns to its pre-compressed shape, releasing its stored energy. This imparts an impulse to fin 112 . Since fin 112 is pivotally attached to projectile 100 , this impulse causes the free end of fin 112 to move away from recess 110 , wherein the fin begins to rotate about pivot pin 446 . As fins 112 begin to rotate away from recess 110 , the water drag forces the fins back until root R of the fins abuts the surface of body 108 .
In embodiments in which spring-biasing element 662 is not used, gap G, as depicted in FIG. 5A , permits water to contact tapered surface 315 of fin 112 , thereby causing sufficient drag to deploy the fin.
The following provides an example of a supercavitating projectile in accordance with the illustrative embodiment.
Diameter of body 108 : 40.0 mm (1.57 in)
Diameter of cavitator 104 : 7.62 mm (0.3 in)
Length of projectile 100 : 483 mm (19.0 in)
Center of Gravity: 279 mm (11.0 in) from cavitator
Fin span: 57.2 mm (2.25 in)
Propellant bay: 230 grams (8 ounces)
Mass of projectile 100 1.93 kg (4.25 lbs)
Material of Construction:
Nose: S7 Tool Steel
Body: S7 Tool Steel
Fins: Titanium
Leaf Spring Buckling Load: 360 Newtons (81 lbf)
Pivot Pin, design pressure: 620.6 MPa (90 Kilopounds/sq in.)
Those skilled in the art will understand that to design a supercavitating projectile, such as those described herein, requires computational fluid dynamic analysis to determine operational stability, etc. These calculations must consider nominal projectile operating depth and yaw angle. Such analysis is within the capabilities of those skilled in the art.
The positioning of fins 112 forward of the aft end of projectile 100 (see, e.g., FIG. 1A , etc.) enables projectiles 100 to be used in conjunction with a stacked projectile launcher, a stylized representation of which appears in FIG. 7 . Such a launcher is available from Metal Storm Ltd. Of Brisbane, Australia.
Launcher 770 accommodates multiple projectiles that arranged nose-to-tail within barrel 772 . In the illustrative embodiment depicted in FIG. 7 , three projectiles 100 - 1 , 100 - 2 , and 100 - 3 are stacked in respective positions 1 , 2 , and 3 .
Within barrel 772 is a plurality of propellant bays 774 - 1 , 774 - 2 , 774 - 3 (collectively or generally, “propellant bay(s) 774 ”). In the illustrative embodiment, each propellant bay is configured as a ring-shaped cavity within barrel 772 that is filled with propellant. Gas ports (not depicted) lead from the propellant bay to the bore of barrel 772 .
Projectiles 100 are separated from one another in barrel 772 by “pusher plugs” 776 . That is, pusher plug 776 - 1 is aft of projectile 100 - 1 and forward of projectile 100 - 2 . Pusher plug 776 - 2 is aft of projectile 100 - 2 and forward of projectile 100 - 3 , etc.
There is one propellant bay 774 for each projectile position, such that each propellant bay contains the propellant responsible for launching an associated projectile. For example, propellant bay 774 - 1 contains the propellant that is used to launch projectile 100 - 1 in Position 1 . Launcher 770 is designed so propellant bay that is associated with a particular projectile is located just aft of the pusher plug for that projectile.
As previously noted, it is the positioning of fins 112 forward of the aft end of projectile 100 (see, e.g., FIG. 1A , etc.) that enables projectiles 100 to be used in conjunction with stacked projectile launcher 770 . In particular, if the fins folded behind the aft end of projectile 100 , there would be no way to stack the projectiles while providing sufficient structural rigidity.
Furthermore, in some embodiments, projectile 100 contains a booster that is ignited once the projectile leaves barrel 772 . In those embodiments, fins 112 are disposed circumferential of a propellant bay disposed proximal to the aft end of the projectile. A benefit of fins 112 disclosed herein is that when deployed, the exhaust gas from the ignited booster never impinges on fins 112 since the fins are forward of the exhaust nozzle of the projectile.
It is to be understood that the disclosure teaches just one example of the illustrative embodiment and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure. For example, after reading this specification, those skilled in the art will know how to design alternative embodiments of the present invention in which projectile 100 is a torpedo or a projectile that is fired in air and then penetrates the water, in which the fins are located other than at the tail of projectile 100 , etc. As a consequence, the scope of the present invention is to be determined by the following claims.
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A supercavitating projectile is disclosed that has deployable fins. The fins are pivotally coupled to the body of the projectile. The fins have two primary states: stowed within a recess at the surface of the projectile and deployed to a radially-extended position relative to the body of the projectile. The fins deploy as the projectile leaves its launch tube. The fins function as a control surface, interacting with the wall of the vapor cavity in which the supercavitating projectile travels.
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CROSS-REFERENCE TO CO-PENDING PROVISIONAL APPLICATION
Priority benefits are claimed under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application Ser. No. 60/029,725, filed Nov. 8, 1996.
FIELD OF THE INVENTION
The present invention relates generally to methods for forming boreholes using cutting heads having low angle cutting faces and, more particularly, to using drilling fluids to alternatively clean the cutting face and create a slurry which is contained within the boundary of the cutting head.
BACKGROUND OF THE INVENTION
A cutting face of a drill bit is defined as a plane, truncated cone, or other surface positioned immediately behind the leading cutting edge of the drill bit. The cutting face structurally directs the cuttings or tailings away from the leading cutting edge of the drill bit toward a slurry point.
Two types of excavation cutting faces are classified by the angle of attack the cutting face makes with the direction of travel of the cutting head as it excavates through the formation. These two cutting face types are high angle and low angle. A high angle cutting face pushes the newly excavated cuttings ahead of the cutter, while a low angle cutting face directs the excavated material inwardly toward the return flow of drilling fluid.
Examples of high angle cutting faces can be found on currently manufactured Polycrystalline Diamond Compact (PDC) bits. Rotation of a PDC drill bit generates a spiral as the circular motion of the bit combines with the penetration of the bit along the borehole. Material which is excavated by each pass of the cutting edge accumulates ahead of the high angle cutting face where the material is compressed and pushed aside as additional material is excavated ahead of the accumulated material. Although drilling fluids injected behind the cutting face slurry the excavated material for transport away from the excavation area, a portion of the excavated material tends to become compacted in front of the high angle bit, thereby decreasing efficiency, and hence the penetration rate, of the cutter.
An example of a low angle cutting face is shown in FIG. 16 of U.S. Pat. No. 5,622,231, issued to the inventor of the present application. Further examples of low angle cutting faces are shown in FIGS. 1-3 of the present application, as described in greater detail below. As seen from these illustrations, low angle cutting faces typically terminate at an angle point where the inclined surface of the cutting face stops. In this manner, low angle cutting faces direct newly excavated material inward, toward a drilling fluid return flow, rather than pushing the excavated material ahead of the cutting face as with the above-described high angle cutting faces. An example of a drilling fluid return flow used with a low angle cutting face is shown in U.S. Pat. No. 5,622,231, which describes the use of orifices positioned behind the cutting face to direct the drilling fluid to the forward end of the borehole to slurry the soil loosened by the low angle cutting face for excavation. Typical drilling fluids may be a liquid, gas, foam, or a mixture having solids suspended in the mixture.
Low angle cutting faces are typically used in loose or unconsolidated soils, whereas high angle (rotary) drill bits are typically used in more firm or rocky soils. However, low angle cutting faces are relatively inefficient and often become clogged due to the tendency of soil to become compacted ahead of the angle point along the inclined surface of the cutting face.
Additionally, low angle cutting heads are used almost exclusively in place of high angle (rotary) cutting heads for delicate drilling operations (such as drilling a borehole immediately beneath an Aboveground Storage Tank (AST) for purposes of determining whether the AST is leaking). Low angle cutting heads are preferred for these delicate operations because they do not typically induce undesirable vibrations or impacts to the adjacent floor of the AST. However, prior low angle cutting heads (such as that shown in U.S. Pat. No. 5,622,231) direct drilling fluid ahead of the cutting face to help slurry the excavated material, and this drilling fluid tends to migrate into the surrounding formation where it can weaken the formation and present a potential hazard to the AST.
Thus, there is a need for more efficient low angle cutting heads which are less susceptible to becoming clogged due to soil compaction along the cutting face. Additionally, there is a need for improved low angle cutting heads which may be used safely for delicate drilling operations such as drilling boreholes beneath ASTs.
It is with regard to this background information that the improvements available from the present invention have evolved.
SUMMARY OF THE INVENTION
One object of the present invention is to increase the efficiency of cutting heads which utilize low angle cutting faces, thereby increasing the speed with which such a cutting head can penetrate a formation to form a borehole.
A second object of the present invention is to provide a method for forming a borehole in an unconsolidated formation without disturbing the formation around the borehole. Such a method would find particular use for investigating Aboveground Storage Tanks (ASTs) such as by drilling a borehole directly under an AST to detect leaks without disturbing the formation beneath the AST or damaging the bottom of the AST.
In one preferred embodiment, the present invention comprises a method of using a cutting head having a low angle cutting face to form either a lateral or a vertical borehole. The cutting face includes a beveled surface defined between a leading cutting edge at one end and an angle point which denotes the opposite end of the cutting face. A manifold or nozzle having at least one orifice is positioned within the cutting head and the method of the present invention includes supplying pressurized drilling fluid to the orifices to create drilling fluid streams, and directing the drilling fluid streams to impinge directly on the beveled surface of the low angle cutting face. The drilling fluid streams act to clean excavated formation material which normally accumulates on the beveled surface. Since the accumulation and compaction of the excavated material is primarily responsible for clogging the cutting head and slowing the progress of the borehole formation, the use of the drilling fluid streams to clean the cutting face increases the efficiency of the cutting head. The present invention thus distinguishes prior art cutting heads which only use drilling fluids to slurry the excavated material and not to clean the low angle cutting face.
In a first embodiment, the orifices are contained within an annular manifold which is positioned forward of the angle point along a circumference of the beveled surface. In a second embodiment, the orifices are contained within a nozzle which is positioned rearward of the angle point along a central axis of the cutting head. Thus, although positioned behind the angle point, the central location of the nozzle allows the drilling fluid streams to directly impinge the beveled surface of the cutting face.
In an alternative embodiment, the present invention comprises a method of forming a borehole in a surrounding formation without disturbing the formation immediately adjacent to the borehole. The method entails allowing the excavated material to pass over the beveled surface of the low angle cutting face before contacting the excavated material with drilling fluid to form a slurry behind the angle point which denotes the rear end of the cutting face. The slurry is then evacuated through the cutting head to the origin of the borehole to prevent the drilling fluid from migrating into the surrounding formation. In its preferred embodiment, the method uses a pair of concentric pipes positioned within the cylindrical cutting head to form three separate fluid conduits. The concentric pipes are positioned within the interior of the cutting head so that the three fluid conduits remain a distance behind the low angle cutting face. Drilling fluid and compressed air are directed through the two outer conduits to form a turbulent fluid-air mixture which mixes with the excavated material to form a slurry that is contained within the confines of the cutting head. A vacuum is then applied to the third conduit to control the pressure within the cutting head and evacuate the slurry before any drilling fluid or compressed air can escape to the surrounding formation. Additionally, provision is made for the concentric pipes to move in relation to the cutting head, thereby allowing the cutting head to be abandoned in the formation (to help prevent collapse of the borehole) while the concentric pipes are withdrawn for reuse with a new cutting head.
As noted above, the alternative embodiment may be used with ASTs or similar structures where it is desired to form a borehole under the structure without disturbing either the structure itself of the surrounding formation under the structure. In addition to checking for leaks, a borehole may be used to sample the formation material under the structure, inject sealant to close a leak in an AST, or install additional detection and monitoring devices below the AST or other structure. Thus, the present invention provides important benefits over prior art cutting heads including high angle rotary bits and pneumatic hammers which could damage an AST due to the shock and vibration which accompanies the formation of a borehole, as well as low angle cutting heads which do not provide for containing the drilling fluids used to slurry the excavated material.
A more complete appreciation of the present invention and its scope can be obtained from understanding the accompanying drawing, which is briefly summarized below, the following detailed description of presently preferred embodiments of the invention, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a low angle cutting face penetrating soil in a horizontal direction and utilizing the fluid impingement technique of the present invention.
FIG. 2 is a fragmented cross-sectional view of a beach umbrella anchor with a low angle cutting surface penetrating sand in a vertical direction and utilizing the fluid impingement technique of the present invention.
FIG. 3 is cross-sectional view of an alternative embodiment of a low angle cutting face which utilizes drilling fluid to slurry the excavated material while preventing the drilling fluid from migrating into the surrounding formation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a first embodiment of a low angle cutting head 20 which utilizes the direct fluid impingement technique of the present invention. The cutting head 20 includes a low angle cutting face 22 which is defined by an inclined or beveled surface 24 extending between a leading cutting edge 26 of the bit 20 and an angle point 28. As the cutting head 20 progresses through an earthen formation 30, the leading cutting edge 26 cuts the formation 30 so that the excavated material 32 is forced up the beveled surface 24 of the cutting face 22.
A drilling fluid manifold 34 is preferably positioned slightly forward of the angle point 28. The drilling fluid manifold 34 is similar to the manifold described in U.S. Pat. No. 5,622,231, and includes a number of orifices 36 for directing high pressure streams 38 of the drilling fluid. However, the manifold 34 differs from the manifold shown in U.S. Pat. No. 5,622,231 due to the placement of the manifold 34 ahead of the angle point 28 (i.e., between the angle point 28 and the leading cutting edge 26). This forward placement of the manifold 34 allows the drilling fluid streams 38 to be directed at the beveled surface 24 of the low angle cutting face 22 as opposed to simply directing the streams 38 forward to slurry the excavated material 32 as described in U.S. Pat. No. 5,622,231. The forward placement of the manifold 34 also decreases the distance the drilling fluid is required to travel to reach the beveled surface, thereby enhancing the precision of the fluid streams 38. By directing the fluid streams 38 toward the beveled surface 24 as shown in FIG. 1, the drilling fluid acts to force the newly excavated material 32 away from the cutting face 22.
The use of the fluid streams 38 to clean the cutting face 22 in this manner increases the efficiency and thus the penetration rate of the cutting head 20 by preventing the cutting head 20 from becoming clogged behind compacted excavated material 32 which would normally accumulate on the cutting face 22. Of course, once the drilling fluid streams 38 have cleaned the beveled surface 24 of the cutting face 22, the drilling fluid forms a slurry 40 with the excavated material 32. The slurry 40 is directed toward the hollow interior of the cutting head 20 and forms a return flow, represented by the arrow 42 in FIG. 1, for removing the excavated material 32 from the borehole formed in the formation 30.
Thus, the cutting head 20 and the manifold 34 differ from previously described cutting heads by directing the drilling fluid so that it directly impinges on the cutting face 22 as opposed to simply directing the fluid toward the excavated material 32 to form a return slurry. While the drilling fluid streams 38 ultimately deflect off the beveled surface 24 and mix with the excavated material 32 to form a return slurry 40, the fluid streams 38 are first beneficially used to clean the low angle cutting face 22.
FIG. 2 illustrates one particular application of the direct impingement method described above. A cutting head 50 having a low angle cutting face 52 is attached to a bottom end of a lower pole 56 of a beach umbrella which is designed to be inserted into beach sand 58 to a depth of 6-12 inches.
In its preferred embodiment, the lower pole 56 is approximately 1.25 inches in diameter and approximately 4 feet in length. An upper portion 60 of the lower pole 56 is enlarged in diameter to allow an upper pole (not shown) to telescopically extend from the lower pole 56.
Similar to the cutting head 20 shown in FIG. 1, the cutting head 50 in FIG. 2 utilizes a nozzle 62 having a plurality of orifices 64 which direct fluid streams 66 toward the interior surface of the cutting head 50 and at the low angle cutting face 52 to clean the cutting face 52 and to prevent the accumulation of sand 58 on the interior surface of the cutting head 50 as the pole 56 is inserted into the sand 58. However, unlike the manifold 34 which extends about the circumference of the cutting face 22 in FIG. 1, the nozzle 62 in FIG. 2 is positioned along the central axis of the cylindrical pole 56. In this manner, the nozzle 62 can be positioned behind (i.e., above) the angle point 68, which defines the rear or top end of the cutting face 52, while still allowing the orifices 64 to direct the fluid streams 66 toward the angled surface of the cutting face 52. By moving the nozzle 62 beyond the angle point 68, the orifices 64 are less likely to become clogged by sand as the cutting head 50 is inserted into the sand 58.
A supply tube 70 supplies the drilling fluid to the nozzle 62 in a manner described below. After the fluid streams 66 clean the sand 58 from the cutting face 52, the used drilling fluid mixes with the sand 58 to form a slurry 72. As the lower pole 56 is inserted into the sand 58, the slurry 72 is forced upward into the bottom end of the lower pole 56 past the supply tube 70. A plurality of vent holes 74 formed within the lower pole 56 allow a portion of the pressurized slurry 72 to be released to the atmosphere as the pole 56 is inserted, although much of the wet sand 58 will remain within the interior of the cutting head 50. A deflection collar 76 is preferably attached about the circumference of the pole 56 at a position slightly above the vent holes 74, as shown in FIG. 2, to deflect the slurry downward as the slurry vents through the holes 74. In this manner, the deflection collar 76 also preferably acts as a depth limiter ensuring that the pole 56 is not inserted to a depth greater than the position of the collar 76.
Because the beach umbrella illustrated in FIG. 2 must comprise a self-contained excavation device, it is necessary to provide within the lower pole 56 a means for storing the drilling fluid as well as a means for pressurizing the drilling fluid. In the preferred embodiment, the drilling fluid comprises water 80 stored within a sealed compartment 82 formed within the cylindrical lower tubing 56. A refill valve 84 extends through an opening formed in the top of the water compartment 82. The refill valve 84 includes an upper collar 86 which extends above the compartment 82 and a lower collar 88 which extends into the compartment 82. The upper collar 88 retains a coil spring 90 which tends to bias the refill valve 84 to a closed position as shown in FIG. 2. A seal 92 within the compartment 82 contacts the lower collar 88 and provides a water tight seal within the compartment 82 when the refill valve 84 is closed.
The compartment 82 may be filled with water 80 from the top end of the lower tubing 56 once the upper collar 86 is depressed to overcome the bias of the coil spring 90 and open the refill valve 84. Once the compartment 82 has been nearly filled with water as shown in FIG. 2, compressed air may be added to an air chamber 96 extending above the level of the water 80. An air control valve 100 preferably extends from the top of the refill valve 84 and provides access through the refill valve 84 to the air chamber 96 within the compartment 82. The air control valve is preferably accessible by standard air chucks for charging the air chamber 96 with pressurized air. Once the air chamber 96 is charged, the pressurized air cooperates with the coil spring 90 to maintain the lower collar 88 pressed against the seal 92, thereby preventing the water 80 from leaking from the compartment 82.
An upper end of the supply tube 70 extends into the bottom of a release valve 104, while a second supply tube 106 extends from the top of the release valve 104 to the bottom of the compartment 82 as shown in FIG. 2. The release valve 104 includes a button 108 extending to the exterior of the tubing 56, and a coil spring 110 tends to bias the button 108 to a position where release valve 104 is closed. Thus, once the compartment 82 has been charged with water 80 and pressurized air, a user may depress the button 108 to open the release valve 104 and allow the pressurized water (i.e., the drilling fluid) to pass through the supply tubes 106 and 70 and exit the orifices 64 of the nozzle 62, as described above. Therefore, as the user begins to push a leading cutting edge 114 of the cutting head 50 into the sand 58, the user preferably depresses the button 108 to allow the pressurized water streams 66 to be directed at the cutting face 52 of the cutting head 50. As described above, the streams 66 tend to clean the cutting face 52 as the cutting edge 114 penetrates the sand 58, thereby preventing compaction of the sand within the cutting head 50 and enhancing the ease with which the cutting head 50 is inserted into the sand 58.
FIG. 3 illustrates an alternative embodiment of the cutting head shown in FIGS. 1 and 2 for use in situations where it is desirable to prevent drilling fluid from migrating into the formation 120. While the cutting heads 20 and 50 in FIGS. 1 and 2 utilize drilling fluid streams directed at the respective cutting faces 22 and 52 to clean the cutting faces and enhance the efficiency of the cutting heads, no provision is made with these cutting heads 20 and 50 to contain the used drilling fluid. Thus, although a majority of the drilling fluid is directed back through the interior of the cutting heads 20 and 50 (as a slurry with the excavated material), a portion of the drilling fluid typically escapes to the surrounding material where it may weaken the formation surrounding the cutting head.
Thus, the cutting head 122 in FIG. 3 does not direct drilling fluid at its cutting face 124, but rather utilizes a series of three annular conduits to create a slurry within the confines of the cutting head 122 and then suction that slurry away before any drilling fluid escapes into the surrounding formation. Towards this end, the cutting head 122 includes within its cylindrical interior two concentric pipes consisting of an outer pipe 128 and an inner pipe 130. The combination of the cylindrical cutting head 122 and the two pipes 128 and 130 forms three concentric annular conduits: a first conduit 136 defined between the inner wall of the cutting head 122 and the outer wall of the outer pipe 128; a second conduit 138 defined between the inner wall of the outer pipe 128 and the outer wall of the inner pipe 130; and a third conduit 140 defined within the interior of the inner pipe 130.
As shown in FIG. 3, a leading cutting edge 144 of the cutting head 122 directs the loosely compacted formation material past the cutting face 124 and into the interior of the cutting head 122. The compacted formation material preferably extends within the cutting head 122 so that a material boundary 150 is positioned beyond the angle point 146 which denotes the rear limit of the cutting face 124.
In order to create a slurry within the interior of the cutting head 122, drilling fluid 154 is preferably pumped through the first conduit 136 where it is passes through an orifice 156 formed between a flared end 158 of the outer pipe 128 and the interior surface of the cutting head 122. The drilling fluid 154 expelled from the orifice 156 preferably mixes with vent or compressed air from the second conduit 138 to form a turbulent fluid-air mixture which is directed toward the material boundary 150. The turbulent fluid-air mixture thus mixes with the excavated formation material at the boundary 150 to form a slurry 160 which is directed to the third conduit 140 (i.e., the interior of the inner pipe 130) by the application of a partial vacuum to the third conduit 140. Additionally, the cross-sectional area of the third conduit 140 (i.e., the inside diameter of the inner pipe 130) is relatively large to help prevent clogging of the conduit 140 by permitting passage of large pieces of the excavated formation material 120.
The cutting head 122 can thus be used in a variety of situations where it is imperative to form a borehole without disturbing the surrounding formation 120. For example, the cutting head 122 may be extended beneath an Aboveground Storage Tank ("AST") without loosening the formation 120 adjacent to the cutting head 122. Furthermore, to prevent the borehole from collapsing, the cutting head 122 may be left behind in the borehole while the outer and inner pipes 128 and 130, respectively, may be withdrawn from the cutting head 122 upon completion of the borehole.
Of course, care must be taken to regulate the pressure of both the supply and the return conduits (136, 138 and 140) to prevent infiltration of the drilling fluid into the formation. Additionally, the supply and return pressures must also be properly controlled to prevent overpressures resulting in blowouts into the formation or underpressures leading to a collapse of the borehole.
Presently preferred embodiments of the present invention have been described with a degree of particularity. These descriptions have been made by way of preferred example and are based on a present understanding of knowledge available regarding the invention. It should be understood, however, that the scope of the present invention is defined by the following claims, and not necessarily by the detailed description of the preferred embodiments.
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A method of forming boreholes using a cutting head having a low angle cutting face includes positioning orifices within the cutting head to direct pressurized streams of drilling fluid to impinge directly on the cutting face. The pressurized fluid streams clear excavated material away from the cutting face to increase the efficiency of the cutting head. In one embodiment, the orifices are positioned within the cutting face, while a second embodiment positions the orifices behind the cutting face. An alternative method provides for the stealthy formation of boreholes without disturbing the surrounding formation. The method includes positioning an orifice within the cutting head behind the cutting face to direct drilling fluid toward excavated material which has accumulated within the cutting head to a point behind the cutting face. The drilling fluid mixes with the excavated material to form a slurry while an interior pipe vacuums the slurry from the cutting head before the drilling fluid migrates to the surrounding formation.
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FIELD OF INVENTION
[0001] The present invention concerns subsea umbilicals having a required weight to diameter ratio.
BACKGROUND
[0002] Subsea umbilicals often require a specific weight to diameter ratio and/or a minimum submerged weight to achieve on-bottom stability. The specific weight to diameter ratio is often a customer requirement and depends on the intended application.
[0003] Presently, to fulfil higher weight to diameter (w/d) ratio requirements, excess steel armour is commonly applied to the umbilical. The amount of steel armour required to obtain the w/d ratio thus exceeds the amount required for sufficient mechanical strength.
[0004] The excess steel armour comprises either polyethylene (PE)-sheathed steel wires incorporated in the umbilical during the lay-up process, or steel armouring wound around the element bundle of the umbilical after lay-up (traditional armouring process).
[0005] The present methods for achieving a specific w/d ratio present a number of disadvantages. To achieve a compact cross section there is often not room for circular weight elements within the umbilical (i.e. excess PE-sheathed steel wires). Moreover, the alternative method using traditional outer armouring causes the umbilical to have a larger outer diameter. Thus, in many instances there is presently no solution for obtaining a subsea umbilical having a compact cross section, and which fulfils a required w/d ratio. An umbilical having a compact cross section is desired since it means that longer delivery lengths of umbilical can be achieved for a given reel/basket length capacity compared to an umbilical having a larger cross section. In addition to an increased cross section, the use of excess steel armouring increases the cost of the umbilical. Said increase is both due to increased material costs and a more complicated manufacturing process.
[0006] The present invention aims to provide a subsea umbilical having a required w/d ratio while alleviating at least some of the disadvantages of the prior art.
SUMMARY OF THE INVENTION
[0007] The present invention provides a subsea umbilical, wherein a specific weight to diameter (w/d) ratio, minimum submerged weight per length (kg/m), or specific gravity, is obtained by use of at least one sheath made of a polymer composite comprising a high density filler, hereinafter termed a “polymer composite”. The invention is further defined by the appended claims, and in the following:
[0008] In one aspect, the present invention provides an umbilical for subsea applications having at least one longitudinal internal element and at least one sheath, the sheath is formed by extrusion, and said internal element is suitable for communicating fluids, electrical power or signals, or for carrying loads, and wherein the sheath is made of a polymer composite comprising a high density filler, the polymer composite having a density in the range of 3 to 11 g/cm 3 .
[0009] In one embodiment of the umbilical according to the invention, the amount of high density filler is in the range of 20 to 90 w/w % based on the total weight of the polymer composite.
[0010] In one embodiment of the umbilical according to the invention, the high density filler is metal based, the metal preferably selected from the group of chromium, nickel, copper, copper oxide, steel, iron, iron oxide, barium sulfate, tungsten, molybdenum and mixture thereof, and having a density of more than 4 g/cm 3 .
[0011] In one embodiment of the umbilical according to the invention, the polymer in the polymer composite comprises at least one polymer selected from the group of high density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), polyurethane (PU), polyamide (PA), and PBT (polybutylene terephthalate).
[0012] In another aspect, the present invention provides for the use of a polymer composite, comprising a high density filler, in a sheath of an umbilical to achieve a minimum submerged weight to length (kg/m), the polymer composite preferably having a density in the range of 3 to 11 g/cm 3 .
[0013] In one embodiment of the use according to the invention, the amount of high density filler is in the range of 20 to 90 w/w % based on the total weight of the polymer composite.
[0014] In one embodiment of the use according to the invention, the high density filler is metal based, the metal preferably selected from the group of chromium, nickel, copper, copper oxide, steel, iron, iron oxide, barium sulfate, tungsten molybdenum, and mixture thereof, and having a density of more than 4 g/cm 3 .
[0015] In one embodiment of the use according to the invention, the polymer in the polymer composite comprises at least one of HDPE, PE, PP, PU, PA and PBT.
[0016] In one embodiment, the use according to the invention is for subsea applications, wherein the umbilical has at least one longitudinal internal element, the sheath is formed by extrusion, and said internal element is suitable for communicating fluids, electrical power or signals, or for carrying loads, wherein the density of the polymer composite is such that the umbilical achieves a minimum submerged weight to length (kg/m).
[0017] In yet another aspect, the present invention provides a method of manufacturing an umbilical having a minimum submerged weight to length (kg/m), comprising the step of:
providing at least one longitudinal element suitable for communicating fluids, electrical power or signals, or for carrying loads; determining the density and thickness of a sheath required to obtain the minimum submerged weight to length (kg/m); and extruding a sheath around the longitudinal element, the sheath made of a polymer composite comprising a high density filler and having a density in the range of 3 to 11 g/cm 3 such that the minimum submerged weight to length (kg/m) is obtained.
[0021] In one embodiment of the method according to the invention, the amount of high density filler is in the range of 20 to 90 w/w % based on the total weight of the polymer composite.
[0022] In one embodiment of the method according to the invention, the high density filler is metal based, the metal preferably selected from the group of chromium, nickel, copper, copper oxide, steel, iron, iron oxide, barium sulfate, tungsten molybdenum, and mixture thereof, and having a density of more than 4 g/cm 3 .
[0023] In one embodiment of the method according to the invention, the polymer in the polymer composite comprises at least one of HDPE, PE, PP, PU, PA and PBT.
[0024] In one embodiment of the umbilical according to the invention, at least one sheath is a surrounding sheath external to all the longitudinal elements of the umbilical. Thus, the at least one sheath is an outer sheathing or the outermost layer of the umbilical.
[0025] The term umbilical as used in the present application is intended to cover cables such as power cables and load bearing cables, in addition to the commonly used meaning wherein an umbilical may comprise multiple elements, such as power phases, load bearing elements, optical fibers, hydraulic fluid lines and similar.
[0026] The term longitudinal element as used in the present application is intended to cover elements present in an umbilical, such as power phases, load bearing elements, optical fibers, hydraulic fluid lines and similar.
[0027] In all aspects and embodiments of the invention, the polymer composite may have a density in the range of 3 to 11 g/cm 3 , 4 to 11 g/cm 3 , 5 to 11 g/cm 3 or 6 to 11 g/cm 3 .
[0028] In all aspects and embodiments of the invention, the amount of high density filler may be in the range of 20 to 90, 30 to 90, 40 to 80, or 40 to 70 w/w % based on the total weight of the polymer composite.
[0029] In all aspects and embodiments of the invention, the density of the high density filler is more than 4, more than 5, more than 6, or preferably more than 7 g/cm 3 .
[0030] In a preferred embodiment of the invention, the polymer(s) of the polymer composite may be selected from the group of thermoplastic elastomers (TPE).
[0031] In a specific embodiment, the polymer composite comprises PA (polyamide) and/or PU (polyurethane) as the polymer(s), and tungsten as the high density filler in an amount of 10-60 wt % based on the total weight of the polymer composite.
[0032] One of the reasons for using polymer composites comprising high density fillers is to contribute to the weight of the umbilical if this is needed to make it more seabed stable or to meet the requirements of submerged weight per length that some of the applicants customers may have. The specific gravity SG of an umbilical according to the invention is typically 1.5-3.0, i.e. the umbilical is 1.5-3.0 times heavier than the displaced water.
SHORT DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a cross sectional view of a prior art umbilical.
[0034] FIG. 2 is a cross sectional view of an umbilical according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] A subsea umbilical comprising a prior art solution for obtaining a specific w/d ratio, minimum submerged weight per length (kg/m), or specific gravity, is shown in FIG. 1 . The cross sectional view is of a 127 km long umbilical which the applicant delivered to Total for the Laggan Tormore field. This specific umbilical comprises multiple hydraulic lines comprising a steel tube and a surrounding high density polyethylene (HDPE) sheath, multiple electrical quads, fibre optic elements, PP filler, profiled PE filler, PP yarn and an outer HDPE sheath 1 . To achieve a required specific gravity of 1.82 in seawater (corresponding to a submerged weight to diameter ratio of 81.8 kg/m), 4 layers of steel tape 2 were added to the umbilical. Both the specific gravity and the weight to diameter ratio are calculated based on the tubes and interstices of the umbilical being flooded with seawater. The minimum submerged weight per length (kg/m) is similarly calculated based on the tubes and interstices of the umbilical being flooded with seawater.
[0036] An umbilical according to the invention is shown in FIG. 2 . The umbilical comprises the same internal elements as described in relation to FIG. 1 . However, to obtain an umbilical having the same specific gravity as the one shown in FIG. 1 , both the outer HDPE sheath 1 and the layers of steel tape 2 are replaced by an outer sheathing of a polymer composite 3 comprising a high density filler. The density of the polymer composite is such that the umbilical obtains the required specific gravity without use of any excess layers of steel tape. The thickness of the polymer composite layer 3 depends on its density and other properties such as abrasion resistance.
[0037] The polymer used in the polymer composite may comprise any suitable synthetic polymer base suitable for continuous extrusion, such as, but not limited to, HDPE (high density polyethylene), PE (polyethylene), PP (polypropylene) PU (polyurethane), PA (polyamide) and PBT (polybutylene terephthalate).
[0038] The polymer(s) of the polymer composite may preferably be selected from the group of thermoplastic elastomers (TPE).
[0039] Further, the polymer composite may be applied to the umbilical using a conventional extrusion process, for instance as used when applying a standard HDPE sheathing.
[0040] The filler used in the polymer composite is a high density filler having a density of more than 4 gi cm 3 , more than 5 g/cm 3 , or more than 6 g/cm 3 . The high density filler is advantageously a metal-based filler such as chromium, nickel, copper, copper oxide, steel, iron, iron oxide, barium sulfate, tungsten and molybdenum, or similar. The high density filler may be in any form suitable for an extrudable polymer composite, e.g. particles and fibres.
[0041] A number of high density fillers and polymer composites comprising such fillers are commercially available, for instance those used in the Gravi-Tech™ compounds available from PolyOne Corporation. Further, various polymer composites suitable for extrusion, comprising high density fillers such as tungsten, are disclosed in U.S. Pat. No. 6,916,354 B2.
[0042] The polymer composite may advantageously have a density in the range of 3 to 11 g/cm 3 , 4 to 11 g/cm 3 , 5 to 11 g/cm 3 or 6 to 11 g/cm 3 .
[0043] A preferred polymer composite comprises PA (polyamide) and/or PU (polyurethane) as the polymer(s), and tungsten as the high density filler in an amount of 10-60 wt % based on the total weight of the polymer composite.
[0044] Another suitable polymer composite can comprise PA as the polymer, and 10-30 wt % of chromium, and/or 10-30 wt % of nickel, and/or 1-5 wt % of molybdenum as the high density filler(s).
[0045] Polymer composites in the lower density range may comprise PA (polyamide) and/or PP (polypropylene) as the polymer(s), and barium sulfate as the high density filler in an amount of 60 wt % or more, based on the total weight of the polymer composite.
[0046] The present invention provides a number of advantages such as a more cost effective production since less outer steel armouring is required. This both saves raw material cost and reduced manufacturing time in the armouring machine. It also reduces the need for intermittent storage of semi-finished product on turn tables. Further, for certain design requirements the outer steel armouring can be completely omitted.
[0047] In one embodiment, the umbilical of the invention further has armour elements such as armour wires layer (traditional armouring process) or outer steel armouring, specifically for additional mechanical protection and for tensile strength. Thus, the armour elements are used in combination with the high density composite sheath of the invention.
[0048] In another embodiment, the umbilical of the invention does not comprise any armour elements such as armour wires layer (traditional armouring process), outer steel armouring, excess steel armour comprising polyethylene (PE)-sheathed steel wires incorporated in the umbilical during the lay-up process, or steel armouring wound around the element bundle of the umbilical after lay-up (traditional armouring process) or other composite armour elements or several layers of metallic (e.g. steel) tape.
[0049] Another possible advantage is that the electrical properties of the sheath can be affected by the type of high density filler, in the form of a metal, which is added to the polymer composite. In a possible embodiment such a sheath can be made semi conductive for applications where this is needed, e.g. an inner sheath of power umbilicals.
[0050] A further advantage is that a polymer composite comprising for instance a metal based high density filler is harder than a HDPE sheath and will in many instances provide a better mechanical protection than the HDPE sheath used in current designs.
[0051] In a prior art umbilical the required diameter necessary to obtain a required minimum submerged weight per length (kg/m) will be larger than the one necessary with the proposed polymer metal composite sheath. This means that longer delivery lengths can be achieved for a given reel/basket length capacity since the outer diameter is smaller than a traditionally armoured umbilical.
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An umbilical for subsea applications has at least one longitudinal internal element and a sheath, the sheath is formed by extrusion. The internal element is suitable for communicating fluids, electrical power or signals, or for carrying loads. The sheath is made of a polymer composite having a high density filler, the polymer composite having a density in the range 3 to 11 g/cm3.
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BACKGROUND OF THE INVENTION
A. Field of the Invention
The present invention relates to a multi-stage pump, particularly adapted to operate in bore holes of relatively small width and able to operate effectively against a varying magnitude of pressure head.
B. Brief Description of the Prior Art
A typical reciprocating pump utilizes a reciprocating piston which on an intake stroke causes a flow of water through a check valve into a pumping chamber, and on a discharge stroke moves the fluid from the pumping chamber along the desired flow path. Pumps of this general type have been arranged in multi-stage assemblies, such as that shown in U.S. Pat. No. 1,844,261, Penrod. In that patent, the several pumping units are arranged in end to end relationship, and the several pistons of the pumping units are rigidly interconnected with one another to operate in unison. Thus, the lower or downstream side pumping units experience lesser back pressure, while the uppermost pumping unit experiences the full back pressure against which the pumping assembly operates.
Also, there are known in the prior art various devices which utilize electric power to activate a solenoid to cause a pumping action. Such a device is shown in the Kato et al patent, U.S. Pat. No. 2,788,170, this particular device being adapted for use as an aquarium pump. Representative of yet another pumping configuration is the Hasquenoph et al patent, U.S. Pat. No. 3,514,221.
While there are a wide variety of prior art pumps especially adapted for specialized applications, there is a continuing need for improvement in such pump designs. Accordingly, it is an object of the present invention to provide a multi-stage pump which is quite simple in its basic operating components and its overall configuration, is able to fit in a relatively small diameter hole, is able to operate on a fluid which contains abrasive particles (such as well water having small particles of sand therein) and is able to operate either at a high volumetric flow rate against lower pressure head or at lower volumetric flow rates at higher pressure heads.
SUMMARY OF THE INVENTION
In the multi-stage pump assembly of the present invention, there is a housing means having an intake pumping chamber and a plurality of additional pumping chambers arranged in series for liquid flow into the intake chamber and sequentially through the additional pumping chambers. There are a plurality of pumping elements, each having a downstream face exposed to pressurized fluid from an immediately adjacent downstream pumping chamber and an upstream face exposed to liquid pressure from an immediately adjacent upstream pumping chamber.
For each of said pumping elements, there is a separately operable actuating means to move its related pumping element on a pumping cycle in a first direction on an intake stroke and to urge its related pumping element in a second direction on a discharge stroke. Also, there is a check valve for each pumping chamber to its related upstream pumping chamber, but preventing reverse flow from an upstream pumping chamber to a downstream chamber. Activating means operatively connected to the actuating means causes each of the actuating means to operate in sequence so as to move said pumping elements sequentially through their pumping cycles.
In the preferred form, each actuating means comprises a first retracting means to move its pumping element on its intake stroke, this retracting means desirably being a solenoid. Also, the actuating means comprises a resilient sleeve having a first end secured to the housing and a second end secured to its related pumping element. Each sleeve defines at least a portion of the pumping chamber upstream of its related pumping element.
In the preferred configuration of the check valve of the present invention, there is at least one circumferential ring member surrounding a related chamber, each ring member being provided with radial grooved passageways for flow of fluid therethrough. There is at least one annular flap member having a closed position against the ring member to close the grooved passageways, and an open position wherein a radially inward portion of the flap member is deflected away from the grooved passageways. In the particular configuration shown herein, there is a plurality of such ring members, with grooved passageways being formed on both sides of each ring member. Likewise, there are flap members on each side of each ring member, and compression ring members positioned against the radially outward portions of the flap members.
The several pumping units can be quite conveniently assembled by providing the housing in the form of an elongate tubular member and providing one or more mounting rods lengthwise in the housing. The several solenoids and sleeve members are each mounted to said rod means and located in their proper positions by suitable locating means along the length of the one or more rods. These locating means can be provided quite conveniently in the form of seal ring members which are compressed axially to bear against the tubular housing to locate the solenoids and sleeve members while providing partitions between adjacent pumping chambers.
Other features of the present invention will become apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a semi-schematic longitudinal sectional view showing the main operating components of the pumping assembly of the present invention;
FIG. 2 is a longitudinal sectional view of a first-stage unit of the pumping assembly of the present invention;
FIG. 3 is a transverse sectional view taken through line 3--3 of FIG. 2;
FIG. 4 is a longitudinal sectional view of the outlet end of the pumping assembly;
FIG. 5 is a transverse sectional view taken through line 5--5 of FIG. 4, illustrating the construction of the check valve of the present invention;
FIG. 6 is a sectional view taken along line 6--6 of FIG. 5 and showing in an enlarged scale one of the valve elements of the check valve shown in FIG. 5; and
FIG. 7 through 10 are schematic drawings showing different operating conditions of the valve assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
It is believed that a clearer understanding of the present invention will be achieved by first describing the main operating components, and then describing in further detail the physical details and precise mode of operation of the present invention.
In FIG. 1, there is shown a semi-schematic drawing of the pump assembly, generally designated 10, and comprising a cylindrical housing 12 having an intake end 14 and a discharge end 16. In describing the components of the present invention, the terms "lower" or "rearward" will denote proximity to the intake end 14 while the terms "upper" or "forward" denote proximity to the discharge end 16. The term "inner" denotes proximity to the longitudinal center line of the housing 12, and the term "outer" denotes a location radially outward from the longitudinal center line.
Mounted within the housing 10 are a plurality of pumping units which in the present embodiment are shown as four units, designated 18a, 18b, 18c and 18d, with 18a being the lowermost unit on the "upstream" or intake end of the pump and pumping unit 18d being at the "downstream" or discharge end 16. Each pumping unit 18 comprises a solenoid 20 and a pumping piston 22 made of an electromagnetic material and positioned a short distance upwardly from the solenoid 20. The unit 18 further comprises a sleeve member 24 having at its lower end a check valve assembly 26 and at its upper end an elastic or resilient actuating member 28. The sleeve member 24 is mounted at its forward end to a transverse seal member 30, which provides an upward opening 32 leading from the chamber 34 defined by the sleeve member 24, but which forms a fluid seal in the annular area between the forward end of the sleeve member 24 and the housing 12.
At the intake end 14 there is a screen 36 to prevent entry of large particles into the pump housing 12. At the outlet end 16 there is an uppermost check valve 37, similar in construction to the check valve assemblies 26 of the several units 18a-d and a discharge pipe 38. To indicate at this time the mode of operation of the present invention somewhat briefly, when the lowermost solenoid 20 is activated, its related piston 22 is attracted to the solenoid 20 and thus moves downwardly to stretch its resilient element 28. This causes an enlargement of the volume of the chamber 34 defined by the sleeve element 24, so that fluid from the intake chamber 40 flows through the check valve assembly 26 and into the first pumping chamber 34. Upon deactivation of the same solenoid 20, the urging of the elastic member 28 moves the pumping piston 22 upwardly on its discharge stroke to decrease the volume in the chamber 34 and move the fluid in the chamber 34 through the opening 32 into the annular chamber 42 which surrounds the components of the second stage pumping unit 16b. As the fluid flows into the annular chamber 42 it passes through the second stage discharge chamber 34, and so on upwardly through the pump assembly and out the conduit 38 at the discharge end 16 of the assembly 10.
Each of the pumping units 16a through 16d is operated in a sequential pattern. That is to say, one solenoid 20 is energized for a sufficient length of time to retract its related piston 22 to its full down position against the solenoid 20, and the deactivated to permit its related elastic actuating member 28 to move its related piston 22 upwardly on a discharge stroke. Then a second solenoid 20 of one of the other pumping units 18a through 18d is likewise activated for a short time to move its related piston 22 downwardly and then permit it to move upwardly on its pumping cycle, and so on with regard to the remaining two solenoids 20 of the third and fourth pumping units 16.
An apparatus to act as a power source for the units 18a through 18d is indicated schematically at 39 in FIG. 1. Such an apparatus suitable for providing sequential electrical pulses to power the solenoids 20 is disclosed in U.S. Pat. No. 3,924,165, with the inventor in that apparatus also being Carl L. Otto, Jr. This apparatus is particularly adapted to work off a 60 cycle electrical input to energize the four units sequentially. Electrical connection to the solenoids can be accomplished quite easily by means of wires placed within the housing 12. While the apparatus 39 is shown schematically as being located exteriorly of the housing, it could be formed in an annular configuration and placed within the housing.
As will be disclosed more fully hereinafter, the particular configuration of the pumping assembly 10 operates at a higher volumetric flow rate when working against a lower pressure head, and has the capability of also pumping against a much higher pressure head, but at a lower volumetric flow rate.
The physical components of the present invention will now be described in more detail. The cylindrical housing 12 can be provided quite simply in the form of a piece of cylindrical plastic tubing open at both ends and having a nominal diameter of, for example, two inches. To mount the components of the four pumping units 18a through 18d, there are provided four rods 44 positioned just inwardly of the wall of the housing 12 and extending substantially the entire length of the housing 12.
At the inlet end 14 of the housing 12, the intake screen 36 is mounted by a peripheral flange portion to a metal ring 46, held in place by four nuts 48, threaded onto the bottom end of the rod 44. Positioned upwardly of the ring 46 is a seal ring 50 positioned between the lower retaining ring 46 and an upper retaining ring 52. When the entire pumping assembly 10 is assembled and the lower nuts 48 are tightened, the two rings 46 and 52 squeeze the yielding seal ring 50 to form a tight seal at the annular area surrounding the opening at the location of the intake screen 36.
Upwardly from the spacing ring 52 are four spacing sleeves 54, each one of which surrounds a related one of the mounting rods 44. The solenoid 20 is located inside of the four spacing elements 54 and is mounted to the rods 44 by means of ears 56 which are shown more clearly in FIG. 3. The solenoid 20 is or may be of conventional design and is shown herein comprised as a spool member 58 around which copper wire 60 is wound, and containing a ferro magnetic core 62. The conducting wire 60 is surrounded by a fluid tight envelope 64; desirably made of a ferro magnet material.
The piston 22 has a disc-like configuration, and it fits just inside the four mounting rods 44 at a location a short distance upwardly of the solenoid 20. As indicated previously herein, connected to and extending upwardly from the piston 22 is the sleeve member 24 made up of a lower check valve assembly 26 and an upper elastic actuating member 28.
The check valve assembly 26 comprises a rigid cylindrical member 66 having a plurality of circumferential holes 68. Within the cylindrical member 66 there are two check valve ring assemblies 70, each of which is positioned at the location of a related set of circumferential holes 68. One such ring assembly 70 can be seen more clearly with reference to FIGS. 5 and 6. As shown in FIG. 6, there is a middle, more rigid ring 72 having a plurality of circumferential cutouts 74. On opposite sides of the ring 72 are two more flexible rings 76 having a relatively small thickness dimension. On opposite sides of the ring assembly 70, there are a pair of compression rings 78 which press against the radially outward portion of the center ring 72, but permit the radially inward portions 82 of the rings 72 to deform outwardly or away from the center ring 72.
In effect the ring 72 defines a plurality of flow passages 74, each of which begins at an outward location of the ring 72 and terminates at a laterally inward location of the ring 72. At the location of the cutouts or flow passages 74, the ring 72 has a cross-sectional configuration resembling a conventional golf tee having an expanded inward head portion 84 and a relatively narrow outer portion 86. When there is greater pressure outside of the cylindrical member 66, fluid passing into the passageways or cutouts 74 deflects the inward portions 82 of the flap rings 76 outwardly to permit flow of the fluid inwardly through the cylinder 66 (this occurring on the downward or intake stroke of the associated piston 22), and when there is a higher pressure within the cylindrical member 66, the inner edges of the two flap rings 76 are held tightly against the inner portion 84 of the ring member 72, to form a tight seal therewith (this occurring on the discharge stroke of the associated piston 22).
Connected to the forward end of the member 66 is a ring 88, to which is threadedly connected a second ring 90 having an outwardly extending annular flange 92. In an annular recess defined by these two rings 88 and 90, there is retained an annular protrusion 94 at the lower end of the aforementioned elastic actuating member 28. This member 28 is able to stretch in a lengthwise direction, but should be substantially non-elastic with regard to any possible lateral expansion. This could be accomplished by providing the member 28 with reinforcing strands located circumferentially around the member 28. This member 28 has at its forward end a second protruding portion 96 which is in turn retained by two rings 98 and 100, which are similar in construction to the aforementioned rings 88 and 90. Forwardly of the ring 100, there is a seal member 102, similar to the seal 50 at the intake end of the housing 12 and an upper retaining ring 104. Forwardly of the retaining ring 104 there is a second solenoid 20 of the second upper pumping unit 18b. The components of the other pumping units 18b, c and d are substantially the same as those described with respect to the lower unit 18, so no detailed description of these other pumping units 18b through d is believed to be needed herein. Located above the final pumping unit 18d, there is the aforementioned check valve 37, which can be seen more clearly in FIG. 4. Since the components of this check valve 37 are substantially the same as those of the previously described check valve assemblies 26, these will not be described in detail herein, but will be given numerical designations corresponding to those of the components of the assemblies 26, with a prime (') designation distinguishing those of the valve 37.
The operation of the single pumping unit 18a is readily understandable, it is believed, from the foregoing description with reference to FIG. 1. However, to review this briefly at this point, it can be seen that as the piston 22 moves downwardly by activation of the solenoid 20, the elastic cylindrical member 28 elongates, to increase the volume of the chamber 34 defined by the elastic member 28 and the other cylindrical member 66. This in turn causes an inflow from the annular area 40 through the cutouts or passageways 74 in the two check valve ring assemblies 70, with this inflow causing the flap rings 82 to deflect away from the center ring member 72 to permit fluid flow to the inside pumping chamber 34. Upon deactivation of the solenoid 20, the piston 22 is urged upwardly to travel on its discharge stroke by the force exerted by the elastic member 28. This causes an increase of pressure in the pumping chamber 34 to close the flap rings 82 against the middle ring 72, and discharge the fluid upwardly from the chamber 34.
With regard to assembling the components of the present invention, it can be seen that each pumping unit 18a through 18d comprises essentially a solenoid 20 and a piston and sleeve member 22-24, each having its associated mounting and retaining rings. These units can quite easily be slipped onto the four mounting rods 44 in the proper sequence. With all the components in place, the four nuts 48 at the bottom of the assembly are tightened along with the four nuts 106 at the upper end of the assembly (as seen in FIG. 4) to hold the components firmly in place and press the seal members 50 and 102 in proper sealing relationship. As shown in FIG. 4, an adapting connector 108 can be attached to the discharge end of the housing 12 to provide a seal connection of the discharge pipe 38.
As was disclosed previously herein, one of the advantages of the present inventioon is that it is capable of operating at higher volumetric flow rates against a lower pressure head, and yet capable of operating effectively under conditions of a much higher pressure head, but at a lower volumetric flow rate. This particular operating feature can be understood more readily with reference to FIGS. 7 through 10. For ease of illustration, the solenoids 20 are not shown.
In the operating condition in FIG. 7, let it be assumed that the pumping assembly 10 is adequately primed (i.e., the chambers in the pumping units 18a through 18d are filled with water), and that the pressure at the outlet conduit 38 is at a relatively lower level. With each of the pistons 22 in its full up position, its related actuating sleeve is substantially unstressed and this exerts very little, if any, upward force. In this condition, let it be assumed that one of the pumping units, for example 18c, is activated. The related piston 22 is moved on the intake stroke to its lower position so that there is flow of fluid in the lower pumping chamber 34 of the unit 18b into the pumping chamber of the pumping unit 18c. As soon as the solenoid 20 of the unit 18c is deactivated, the force of the elastic actuating member 28 is sufficient to move the piston 22 upwardly to force liquid in the chamber 34 through the valve assembly of the next upper unit 18d and upwardly through the conduit 38. At the same time, liquid is drawn in through the intake screen 36 upwardly into the two pumping chambers of the lower two units 18a and 18b. Thus, through an entire pumping cycle, where each of the four units 18a through 18d are activated in sequence, each of the pistons 22 goes through its pumping cycle in sequence, and the total volumetric flow is equal to four times the pumping capacity of each of the four pumping chambers 34 when the associated pistons 22 moves through its stroke.
Now let it be assumed that the pumping assembly 10 has not been operated for a period of time, and because of directing the outlet of the conduit 38 into a higher pressure area, there is a much higher back pressure against the assembly 10. As shown in FIG. 8, let it be assumed that, as in the previous example, pumping unit 18c is activated. The solenoid 20 moves the associated piston downwardly on its intake stroke, but on deactivation of the solenoid 20, the elastic actuating member 28 does not have adequate force to work against the pressure in the system to cause the piston 22 of the unit 18c to move upwardly on its discharge stroke. Subsequently, as shown in FIG. 9, two other pumping units are activated, namely 18d and 18a. As each of the pistons 22 of these units moves downwardly, fluid flows into the related pumping chamber 34, and each of the elastic actuating members 28 of the three pumping units 18a, 18c and 18d are urging the fluid in the system upwardly. It is important to note that the force exerted by the three elastic actuating members 28 which have been elongated is cumulative. Thus, the pressure in the lowermost chamber 34 of pumping unit 18a creates a pressure which is substantially uniform and is exerted against the lower side of the piston 22 of the third pumping unit 18c. This pressure on the bottom side of the third uppermost piston 22, along with the force exerted by the elastic actuating member 28 of the third unit 18c is cumulative to cause a yet higher pressure in the chamber 34 of the third unit 18c. This in turn is exerted against the uppermost piston 22 of the fourth pumping unit 18d, and this is added to the further pressure increment contributed by the elastic actuating member 28 of the uppermost unit 18d.
However, let it be assumed that even under the condition of FIG. 9, the back pressure existing in the discharge tube 38 is still high enough to overcome the total pressure provided by the cumulative effect of the pumping units 18a, 18c and 18d. At this point, as shown in FIG. 10, the fourth pumping unit 18b is activated, to add a fourth pressure increment to the total system, and in the particular example shown herein, this is sufficient to cause an increment of flow upwardly through the discharge conduit 38. As the pumping assembly 10 continues to operate under this high back pressure condition, it can be expected that the assembly 10 will reach a stabilized operating condition, where activation of each of the pumping units 18a through 18d causes a movement of its related piston 22 through a shorter increment of travel, and that there is a certain small flow increment with activation of each of the units 18a through 18d, with a correspondingly shorter travel of each of the pistons 22.
In view of the foregoing description, it can be readily appreciated that the operating components of the present invention are relatively simple in structure, and are also quite easy to assemble in operating condition. Also, additonal pumping units can be added to the assembly quite easily for increased capacity. These individual pumping units are so arranged so that the pump can be positioned within a hole of very small diameter. The particular arrangement of the pumping components is such that the presence of abrasive particles such as sand in water, would be less harmful to the pumping assembly of the present invention in comparison to many prior art pump configurations.
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A multi-stage pumping assembly comprising a plurality of pumping units arranged end to end in an elongate cylindrical housing. Each pumping unit comprises a solenoid which when energized causes a pumping piston to retract downwardly on its intake stroke, and when de-energized permits a tension loaded rubber sleeve element to pull the piston upwardly on its discharge stroke. Each of the solenoids is energized in sequence so that the pumping pistons move through their pumping cycles in a sequential pattern. In pumping against lower pressures, each piston is able to move through a longer path of travel on its discharge stroke to effect a higher volumetric flow of liquid. When working against higher head pressures, the pressure exerted by the several pumping pistons, working cumulatively effects a lower volumetric flow of fluid at a higher pressure.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. §119(a) of French Patent Application FR1158898, filed Oct. 3, 2011, and entitled “Process for Fabricating a Silicon-On-Insulator Structure,” the disclosure of which is hereby incorporated herein by this reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a silicon-on-insulator structure comprising a silicon layer, a buried oxide layer the thickness of which is 25 nm or less, and a support substrate, and to a process for fabricating such a structure.
BACKGROUND
[0003] Silicon-on-Insulator (SOI) structures are frequently used in Complementary Metal-Oxide-Semiconductor (CMOS) applications.
[0004] Such structures comprise, from their useful surface to their bottom side: a thin silicon layer; a buried layer made of a dielectric material that is typically an oxide, such as SiO 2 ; and a support substrate. The buried layer made of a dielectric material is often denoted by the acronym BOX for the term “Buried OXide.”
[0005] The thicknesses of the thin silicon layer and the oxide layer may vary depending on the intended applications.
[0006] In particular, the thickness of the thin silicon layer is reduced to a thickness of 50 nanometers (nm) or less, even 20 nm or less, and especially to about 12 nm in order to allow what are called FDSOI (Fully Depleted SOI) structures to be obtained. Such FDSOI structures have the advantage of significantly reducing operational instability and considerably improved performance relative to what are called PDSOI (Partially Depleted SOI) structures in which the thickness of the thin silicon layer is about 70 to 90 nm. The improved performance may include low dynamic power, low leakage current, and/or high transistor density.
[0007] Among these structures, UTBOX (UTBOX standing for “Ultra-Thin Buried OXide”) structures, having a ultrathin buried oxide layer, show great promise because the extreme thinness of this electrically insulating layer makes it possible to apply a voltage to the back side of the structure (i.e., to the side opposite the thin silicon layer) and therefore to precisely control the operation of the device.
[0008] The term “ultrathin” is understood to mean having a thickness of 50 nm or less.
[0009] The fabrication processes of structures having a buried oxide layer with a thickness of between 25 and 50 nm are, at the present time, quite well characterized and it is possible to produce such structures with a defectivity level that is compatible with subsequent component fabrication.
[0010] However, UTBOX structures with a buried oxide layer having a thickness of 25 nm or less, and particularly of 15 nm or less, can currently only be fabricated with a defectivity level that is not easily compatible with the requirements of component manufacturers.
[0011] More precisely, this defectivity is due to a bubbling or blistering effect that is observed at the bonding interface located between the thin silicon layer and the mechanical support, in the case of an SOI substrate fabricated using the SMARTCUT® process.
[0012] FIG. 1 shows the variation in the defectivity as a function of the thickness of the BOX layer expressed in nanometers (nm).
[0013] The defectivity shown in this graph is the number of bubbles counted on the surface of an SOI structure immediately after the thin silicon layer has been transferred.
[0014] In the case of structures in which the BOX layer has a thickness below 15 nm (the hatched zone of the line in FIG. 1 ), the bubbling is so widespread that it may be impossible or impractical to count the bubbles.
[0015] FIGS. 2A to 2D illustrate the main steps of a first known process for fabricating such a structure employing the SMARTCUT® process.
[0016] With reference to FIG. 2A , an oxide layer 2 is formed on the surface of a donor substrate 31 from which the thin silicon layer will be transferred.
[0017] A weak zone 32 is formed in the donor substrate 31 , at a depth corresponding to the thickness of the thin layer 3 to be transferred, through the oxide layer 2 , for example by implantation of atomic species (represented by the arrows in FIG. 2B ).
[0018] With reference to FIG. 2C , the donor substrate 31 (by way of the oxide layer 2 ) and the receiver substrate 1 are hydrophilically bonded by molecular adhesion.
[0019] This bonding step is followed by a bond-strengthening anneal intended to increase the bond strength.
[0020] Next, a supply of energy, for example thermal energy, causes the donor substrate 31 to cleave in the weak zone 32 .
[0021] In general, the bond-strengthening anneal is carried out at a low temperature (i.e., at a temperature between 200° C. and 550° C.) and the anneal allows the bonding interface to be strengthened and the cleaving of the donor substrate to be initiated in the same step.
[0022] After the non-transferred part of the donor substrate has been detached, a silicon-on-insulator structure ( FIG. 2D ) is obtained to which conventional finishing treatments (rapid thermal annealing (RTA), sacrificial oxidation, etc.) are applied, these treatments being intended to, inter alia, smooth the surface of the thin semiconductor layer 3 and repair implantation-related defects.
[0023] The one or more RTA treatments are typically carried out at a temperature above 900° C.
[0024] In the step of bonding the two substrates, water molecules present at the interface contribute to the bonding of the surfaces.
[0025] However, during the bond-strengthening anneal, water molecules diffuse through the oxide layer 2 , and through a thin native-oxide layer on the surface of the receiver substrate 1 , and react with the silicon of the semiconductor layer 3 and with the silicon of the receiver substrate 1 . The reaction between the water molecules and the silicon may proceed as shown in the following oxidation reaction:
[0000] 2H 2 O+Si→SiO 2 +2 H 2
[0026] This reaction produces molecules of hydrogen gas, which are trapped in the buried oxide layer, the buried oxide layer thus acting as a hydrogen-gas reservoir.
[0027] However, in the case of an ultrathin oxide layer, the layer is not thick enough to store all of the hydrogen gas molecules.
[0028] The buried oxide layer therefore becomes saturated and can no longer absorb the molecules of hydrogen gas. The excess hydrogen accumulates at the bonding interface where it generates defects.
[0029] This is because, as soon as the temperature of the bonded structure exceeds about 300° C., the hydrogen gas subjects defects present at the bonding interface to pressure, forming bubbles.
[0030] This effect is described in the following articles: “A model of interface defect formation in silicon wafer bonding”, S. Vincent et al., Applied Physics Letters, 94, 101914, (2009); and “Study of the formation, evolution, and dissolution of interfacial defects in silicon wafer bonding”, S. Vincent et al., Journal of Applied Physics, 107, 093513, (2010).
[0031] By carrying out an anneal at a temperature of between 300° C. and 400° C., the generation of hydrogen gas is limited and thus the bubbling effect is prevented.
[0032] Thus, after the cleaving, a structure with a very low defectivity is obtained.
[0033] However, the bonding interface still needs to be adequately strengthened and the SOI substrate still needs to be finished without allowing bubbles to appear in the finishing steps.
[0034] At temperatures of 900° C. and above, hydrogen gas is soluble in silicon.
[0035] After the cleaving, the objective is therefore to increase the temperature to 900° C. (a temperature above which hydrogen outgases from the silicon) rapidly enough to set the structure and thus to prevent generation of defects at the bonding interface.
[0036] However, after a conventional RTA treatment micro-bubbles are observed to form in the structure and, although these bubbles are much smaller than those observed after the known process described with reference to FIGS. 2A to 2D , they make it impossible to use the structures for the intended applications.
[0037] This is a result of the fact that during the RTA the temperature was not increased rapidly enough to set the structure and prevent the bubbling effect.
[0038] It is therefore still necessary to develop a process that prevents bubbles from forming in the case of structures in which the BOX layers are 15 nm or less in thickness, and, in particular, 10 nm or less in thickness.
[0039] To prevent H 2 from forming, document WO 2010/049496 describes a second process, the steps of which are represented in FIGS. 3A to 3E .
[0040] With reference to FIG. 3A , an oxide layer 21 is formed on the surface of the donor substrate 31 .
[0041] A weak zone 32 is formed within the donor substrate 31 at a depth corresponding to the thickness of the thin layer 3 to be transferred, through the oxide layer 21 , for example by implantation of atomic species (represented by the arrows in FIG. 3B ).
[0042] With reference to FIG. 3C , an oxide layer 22 is formed on the surface of the receiver substrate 1 .
[0043] Next, molecular adhesion (oxide/oxide) bonding is used to bond the donor substrate 31 to the receiver substrate 1 , the oxide layers 21 , 22 being located at the interface and together forming the buried oxide layer 2 of the SOI substrate.
[0044] After this bonding step, the donor substrate is cleaved at the weak zone 32 .
[0045] This process achieves good results in terms of defectivity in so far as the H 2 -generating reaction is limited by the presence of the two facing buried oxide layers that form a barrier to water-molecule diffusion.
[0046] Specifically, these molecules cannot reach the oxide/silicon interface, the silicon oxidation reaction cannot take place, and the generation of H 2 molecules is thereby prevented.
[0047] However, bonding substrates by way of their respective oxide layers 21 , 22 has the drawback that the bonding interface is not completely closed. In other words, when the structure is observed with a transmission electron microscope after the finishing anneals (RTA at 1200° C. for 30 seconds), the interface between the two layers (represented by the dot-dash line 23 in FIG. 3E ) may still be seen.
[0048] This incompletely closed interface may create electrical problems that could interfere with the operation of the electronic devices formed in or on the structure.
BRIEF SUMMARY
[0049] To produce a bond having a closed interface, the Applicants have developed an oxide-to-silicon bonding process. In other words, a process in which the oxide layer intended to form the BOX layer is formed only on one of the two substrates, while leaving silicon on the free surface of the other substrate.
[0050] To produce such a bond, and with a view to closing the bonding interface, it is known to plasma activate the surface of the oxide. The plasma activation is intended to increase the bond strength.
[0051] However, such an activation increases the amount of water present at the interface and therefore risks further amplifying the bubbling effect that it is desired to prevent.
[0052] One aim of the invention is therefore to define a process for fabricating a silicon-on-insulator structure having a buried oxide layer, the thickness of which is 25 nm or less, and in particular 10 nm or less, allowing the formation of bubbles or blisters due to hydrogen to be prevented or at the very least reduced (e.g., minimized).
[0053] More precisely, the process may comprise an oxide-to-silicon bond having a completely closed bonding interface obtained without excessive heating of the structure.
[0054] Moreover, the process must be industrializable on existing SOI-structure production lines.
[0055] Another aim of the invention is to provide a silicon-on-insulator structure comprising a buried oxide layer having a thickness of 25 nm or less, and in particular 10 nm or less, and having a very low “bubble” defectivity.
[0056] In accordance with the invention, a process is provided for fabricating a silicon-on-insulator structure comprising a silicon layer, a buried oxide layer having a thickness of 25 nm or less, and a support substrate, the process being characterized in that it comprises the following steps:
[0057] (a) providing a donor substrate comprising the silicon layer and the support substrate, only one of the substrates being covered with the oxide layer;
[0058] (b) forming, in the donor substrate, a weak zone bounding the silicon layer;
[0059] (c) plasma activating the oxide layer;
[0060] (d) bonding the donor substrate to the support substrate, the oxide layer being located at the bonding interface, the bonding being carried out in a partial vacuum;
[0061] (e) implementing a bond-strengthening anneal at a temperature of 350° C. or less, the anneal causing the donor substrate to cleave along the weak zone; and
[0062] (f) applying, to the silicon-on-insulator structure, a heat treatment for repairing defects at a temperature above 900° C.—the transition from the cleaving temperature of step (e) to the defect-repairing temperature of step (f) being achieved at a ramp rate above 10° C./s.
[0063] The term “oxide” is understood in the present text to mean silicon dioxide (SiO 2 ).
[0064] The expression “partial vacuum” is understood to mean that the bonding step is carried out in a chamber in which the pressure is below atmospheric pressure, and in a moisture-free atmosphere (i.e., an atmosphere containing less than 100 ppm of water).
[0065] According to the invention, the bonding step employs a partial vacuum of between 0.1 mbar and 100 mbar, particularly of between 0.5 mbar and 10 mbar, and even more particularly of 1 mbar.
[0066] It is particularly advantageous for the anneal of the bond-strengthening step to be an anneal at a constant temperature lying between 300° C. and 350° C. of between 5 hours and 15 hours in length.
[0067] Optionally, additional mechanical energy may be applied to cleave the donor substrate during or after the bonding anneal.
[0068] An oxygen plasma may be employed in step (c) of activating the oxide layer.
[0069] Moreover, the thickness of the silicon layer, immediately after transfer of the thin layer by the SMARTCUT® process, is advantageously 600 nm or less and may be between 270 nm and 510 nm, and may be equal to 330 nm.
[0070] In some embodiments of the invention, the thickness of the oxide layer may be 15 nm or less.
[0071] The formation of the weak zone may comprise implanting atomic species into the donor substrate.
[0072] Additional embodiments of the invention include a silicon-on-insulator structure comprising a silicon layer, a buried oxide layer having a thickness of 25 nm or less, and a support substrate, the structure being characterized in that the defectivity of the structure in terms of defect clusters is 60 or less.
[0073] According to some embodiments of the invention, the structure is a wafer having a diameter of 300 millimeters (mm).
[0074] The thickness of the silicon layer, after the SOI substrate has been finished, may be 50 nm or less, and particularly 20 nm or less, and even more particularly 12 nm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] Other features and advantages of the invention will become clear from the following detailed description given with reference to the appended drawings in which:
[0076] FIG. 1 is a graph illustrating the variation in the defectivity as a function of the thickness of the BOX layer in a silicon-on-insulator structure;
[0077] FIGS. 2A to 2D illustrate the various steps in a first known process for fabricating an SOI structure;
[0078] FIGS. 3A to 3E illustrate the various steps in a second known process for fabricating an SOI structure;
[0079] FIGS. 4A to 4E illustrate the various steps in the process for fabricating an SOI structure according to the invention;
[0080] FIG. 5A is a histogram showing the bond strength as a function of the pressure during the bonding of the substrates; and
[0081] FIG. 5B is a graph illustrating the optimization of the pressure of the bonding in a partial vacuum with respect to the post-cleaving defectivity.
[0082] In order to make the figures easier to understand, certain very thin layers have been enlarged and the various layers in the figures are therefore not drawn to scale.
DETAILED DESCRIPTION
[0083] The fabrication of a silicon-on-insulator structure having a buried oxide layer that is 25 nm or less in thickness will now be described.
[0084] To form such a structure, a donor substrate is provided from which a silicon layer, intended to form the ultrathin layer of the SOI wafer, may be transferred.
[0085] In so far as the final ultrathin layer results from thinning the transferred layer after the cleaving process, the thickness of the silicon layer transferred from the donor substrate is substantially larger than the thickness of the final silicon layer of the SOI substrate.
[0086] Thus, to form the ultrathin layer of silicon of an SOI substrate (i.e., having a thickness of 50 nm or less), a silicon layer having a thickness of 600 nm or less may be transferred from the donor substrate.
[0087] The donor substrate may be a single-crystal bulk silicon substrate.
[0088] Alternatively, the donor substrate may be a composite substrate. In other words, the donor substrate may comprise a multilayer structure including various materials, the surface layer of which comprises the single-crystal silicon layer to be transferred.
[0089] With reference to FIG. 4A , an oxide layer 2 is formed on the surface of the donor substrate 31 .
[0090] The oxide layer 2 is intended to form the buried oxide layer of the SOI structure.
[0091] The oxide layer therefore has a thickness of 25 nm or less, and may have a thickness of 15 nm or less.
[0092] Specifically, the surface of the donor substrate 31 may be thermally oxidized.
[0093] Alternatively, the oxide may be deposited, for example, by chemical vapour deposition (CVD).
[0094] Alternatively, the oxide layer 2 may be formed on the receiver substrate by exposing the silicon to the surface of the donor substrate.
[0095] However, it may be desirable to form the oxide layer 2 on the surface of the donor substrate 31 , especially when the weak zone is formed by implantation of atomic species. This is because the implantation is then achieved through the oxide layer 2 .
[0096] A weak zone is formed in the donor substrate, and the weak zone defines the silicon layer to be transferred.
[0097] FIG. 4B shows the weak zone 32 being formed in the donor substrate 31 by implantation of atomic species, such as hydrogen and/or helium.
[0098] The implantation energy is chosen so that the weak zone 32 is formed at a depth substantially corresponding to the thickness desired for the layer 3 to be transferred (e.g., a thickness of 600 nm or less, particularly a thickness of between 210 and 570 nm, and even more particularly a thickness of about 330 nm).
[0099] However, the formation of the weak zone is not restricted to an implantation process.
[0100] The weak zone may also be formed by any technique that can introduce atomic species into the donor substrate at the desired depth. For example a diffusion technique may be used.
[0101] With reference to FIG. 4C , the donor substrate 31 is bonded by molecular adhesion to a receiver substrate 1 such that the oxide layer 2 is located at the interface.
[0102] The receiver substrate 1 is typically a silicon substrate, and optionally may be covered with a native oxide.
[0103] Thus, oxide-to-silicon (donor substrate-receiver substrate) bonding is obtained.
[0104] Alternatively, as indicated above, if the donor substrate is not covered with the oxide layer 2 but has its silicon surface exposed, the oxide layer would be formed on the receiver substrate 1 and an oxide-to-silicon (receiver substrate-donor substrate) would also be obtained.
[0105] By employing such a bonding step, there is no risk of an interface that is not completely closed being obtained, in contrast to the case of oxide-to-oxide bonding as mentioned in the introduction.
[0106] Before the substrates are brought into contact, the oxide layer 2 located on the surface of the donor substrate 31 may be subjected to a plasma treatment.
[0107] In some embodiments, the plasma may be an O 2 plasma, but a plasma based on oxygen, argon, nitrogen and/or helium may also be employed.
[0108] The plasma treatment activates the surface of the oxide layer and increases the bond strength.
[0109] The step in which the substrates are brought into contact with a view to bonding them is carried out in a partial vacuum, generally at room temperature.
[0110] Specifically, the substrates to be bonded are placed in a chamber 100 , the interior of which may be depressurized.
[0111] Indeed, the Applicants have observed that carrying out the bonding step in a partial vacuum, and not at atmospheric pressure, allows the formation of bubbles to be substantially reduced.
[0112] In some embodiments, the absolute pressure of the partial vacuum lies between 0.1 mbar and 100 mbar, and, more particularly between 0.5 mbar and 10 mbar.
[0113] Even more advantageously, the Applicants have demonstrated that a partial vacuum with an absolute pressure of 1 mbar allows the presence of water at the bonding interface to be reduced (e.g., minimized) without adversely affecting the bonding quality. Sufficient bond strength is preserved to allow complete transfer of the layer and thus to avoid non-transferred zones being generated in the SOI structure.
[0114] In an SOI substrate, non-transferred zones (NTZs) are holes in the thin silicon layer where the silicon has not transferred to the receiver substrate. These defects are generally due to the bond between the transferred layer and the receiver substrate not being sufficiently strong.
[0115] Therefore, when reducing the amount of water at the interface, care should be taken to ensure that the bond between the substrates is sufficiently strong.
[0116] Furthermore, the atmosphere of the chamber 100 is moisture-free (i.e., an atmosphere containing less than 100 ppm of water).
[0117] This very low moisture content and the partial vacuum compensate for the additional water molecules contributed by the plasma treatment.
[0118] Thus, the amount of water at the bonding interface can be minimized (without, however, reducing the number of water molecules to zero since the bonding will not take place in the absence of water) while, by virtue of the plasma treatment, a bond that is sufficiently strong to prevent non-transferred zones is obtained.
[0119] FIG. 5A illustrates the bond strength E (expressed in mJ/m 2 ) for various pressure values P applied in the chamber 100 during the bonding.
[0120] This histogram shows the results of trials in which a donor substrate including a 10 nm-thick oxide layer that was or was not subjected to an O 2 plasma activation was bonded to a silicon receiver substrate at various pressures.
[0121] For each data pair, the left-hand column corresponds to the case where the bonding was carried out without prior plasma treatment of the substrate, whereas the right-hand column corresponds to the case where the bonding was preceded by an O 2 plasma treatment of the oxide layer covering the donor substrate.
[0122] It may be seen that, when the bonding is carried out in a partial vacuum, the bond strength is lower than when the bonding is carried out at atmospheric pressure (1013 mbar).
[0123] However, the bond strength varies little between 1 and 100 mbar, and a satisfactory value is obtained when a plasma treatment is applied to the donor substrate. Under these conditions, bonding in a partial vacuum does not lead to NTZs.
[0124] However, in the absence of the plasma treatment, the bond strength is too low and the number of non-transferred zones significantly increases.
[0125] FIG. 5B illustrates the variation in the post-cleaving defectivity D (in terms of the number of bubbles and non-transferred zones) as a function of the pressure P applied in the chamber 100 during the bonding of the substrates.
[0126] This graph shows the results of trials in which a donor substrate with a 10 nm-thick oxide layer that was subjected to an O 2 plasma activation was bonded to a silicon receiver substrate at various pressures.
[0127] After the cleaving of the donor substrate, bubbles and non-transferred zones were counted using a visual inspection method.
[0128] It may be seen in this graph that the most advantageous pressure range (in terms of post-cleaving defectivity) lies between 0.1 mbar and 100 mbar.
[0129] A pressure of about one (1) mbar is the optimal pressure for minimizing the presence of water while also minimizing the defectivity. Furthermore, FIG. 5A confirms that a pressure as low as one (1) mbar is not disadvantageous in terms of bond strength and, therefore, in terms of NTZ defects.
[0130] It may therefore be concluded from the above that, to obtain a satisfactory compromise between bubble defects on the one hand and NTZ defects on the other hand, it is desirable both to carry out the bonding in a partial vacuum of between 0.1 and 100 mbar (e.g., about one (1) mbar) and to activate the surface of the donor substrate beforehand by means of a plasma treatment.
[0131] After the substrates 1 and 31 have been brought into contact, a bond-strengthening heat treatment is carried out that also has the effect of initiating the cleaving of the donor substrate 31 in the weak zone 32 .
[0132] For this purpose, a tool (oven) other than the bonding tool is used.
[0133] This heat treatment may comprise an anneal carried out at a temperature of 350° C. or less at atmospheric pressure.
[0134] It may be particularly advantageous for the cleaving to initiate at a constant temperature lying between 300° C. and 350° C.
[0135] If the temperature of the anneal is too low (for example lower than 250° C.) it may not sufficiently strengthen the bond and might therefore lead to non-transferred zones being formed.
[0136] The anneal may last a number of hours, such as from 5 hours to 15 hours.
[0137] During this anneal, the cleaving of the donor substrate 31 in the weak zone 32 is initiated.
[0138] The cleaving may be assisted or triggered by applying another energy source, such as an additional source of mechanical energy.
[0139] Thus, for example, a blade may be inserted into the weak zone 32 .
[0140] As will be seen in more detail below, applying such a low-temperature bond-strengthening anneal, combined with bonding in a partial vacuum, unexpectedly allows the bubbling effect observed in the final SOI structure to be reduced.
[0141] With reference to FIG. 4D , after the cleaving process, a structure comprising the receiver substrate 1 , the oxide layer 2 , and the transferred layer 3 is obtained.
[0142] To form the final SOI structure (illustrated in FIG. 4E ), various finishing treatments are carried out on the thin silicon layer.
[0143] After these treatments have been carried out, the final layer 3 ′ is substantially thinner than the layer 3 that was transferred.
[0144] Moreover, an RTA treatment may be carried out to repair defects in the layer 3 ′.
[0145] The treatment may be carried out at a temperature above 900° C. (e.g., at about 1200° C.).
[0146] To prevent bubbles forming in the final SOI substrate, it may be desirable to reach the temperature of the RTA treatment rapidly.
[0147] Thus, it may be desirable to pass from the temperature of the bond-strengthening and cleaving anneal to the temperature of the RTA treatment at a ramp rate of at least 10° C. per second.
[0148] This is because a temperature rise that is this rapid allows the structure to be set and prevents the formation of bubbles.
[0149] This treatment may be carried out in a chamber equipped with an infrared lamp, allowing the treatment temperature plateau to be reached in a short time. It may be carried out in, for example, an oven or an epitaxial reactor.
[0150] Once a temperature of about 900° C. is reached, there is little or no risk of bubbling occurring because, above this temperature, outgassing of the hydrogen gas occurs.
[0151] The RTA treatment may last for about a number of seconds to a number of minutes (e.g., between 30 seconds and 15 minutes).
[0152] After this treatment, it is unimportant what ramp rate is used to return to room temperature since the hydrogen has diffused beyond the bonding interface and is, therefore, not capable of generating bubbles.
[0153] The influence of the transferred layer 3 has also been demonstrated by the Applicants.
[0154] Comparative trials were carried out with weak zones of 32 nm to 275 nm, 330 nm, and 510 nm.
[0155] The greater the depth of the weak zone, the smaller the number of bubbles observed after the cleaving process.
[0156] However, the closer the depth of the weak zone is to these limits, the greater the number of micro-bubbles observed after the RTA treatment.
[0157] The optimal thickness of the weak zone seems to be located at about 330 nm.
[0158] Moreover, it is important to note that the combination of bonding in a partial vacuum and a low-temperature bond-strengthening anneal results in an unexpected improvement in terms of bubbling.
[0159] Specifically, the Applicants have observed that implementing, in the known SMARTCUT® process, either bonding in a partial vacuum or a low-temperature bond-strengthening anneal does not sufficiently reduce the bubbling.
[0160] The table below demonstrates the synergistic effect of these two treatments, relative to a known SMARTCUT® process and a SMARTCUT® process in which only one of these treatments is carried out.
[0161] The table shows, at various points in the process for fabricating an SOI substrate, the number of bubbles counted using a visual inspection method and/or using a KLA-Tencor SP2 inspection tool available from KLA Tencor of Milpitas, Calif.
[0162] In any case, the SOI structure is produced from a silicon donor substrate covered with a 25 nm-thick oxide layer and implanted with ions so as to form a weak zone at a depth of 330 nm, and from a silicon receiver substrate.
[0000]
SMARTCUT ®
SMARTCUT ®
SMARTCUT ®
process with
process with
process with bonding
Known
bonding in a
low-
at 1 mbar and 300° C.
SMARTCUT ®
partial vacuum
temperature
anneal (embodiment
Process Step
process
(1 mbar)
(300° C.) anneal
of the invention)
Post-cleaving
Several hundred
A few tens of
No or very few
No or very few
(visual
visible defects
visible defects
visible defects
visible defects (no
inspection)
(essentially
(bubbles and
(no bubbles)
bubbles)
bubbles)
NTZs)
Post-RTA (SP2
—
—
Extensive
No bubbling observed
and visual
micro-bubbling
either by visual or
inspection)
observed by
SP2 inspection
visual
inspection
After sacrificial
—
—
—
No bubbling observed
oxidation (SP2
inspection)
Final SOI
—
—
—
AC < 60 interface
substrate (SP2
closed
inspection)
[0163] These data show that, for the known SMARTCUT® process, bubbling may be widespread after the cleaving process. The bubbling was, therefore, not measured in subsequent steps of the process for fabricating this SOI substrate.
[0164] For the process in which the bonding was carried out at a pressure of one (1) mbar, a significant decrease in the bubbling was observed after the cleaving process.
[0165] However, the level of bubbling was still relatively high and, therefore, the bubbling was not measured in subsequent steps of the process for fabricating this SOI substrate.
[0166] For the process in which the bonding was carried out, in a known way, at atmospheric pressure, but in which a bond-strengthening and cleaving anneal was carried out at 300° C. (or less), bubbling was not observed.
[0167] However, after the RTA treatment, micro-bubbling was observed, visible to the naked eye, over substantially the entire surface of the SOI substrate. The term “micro-bubbling” is understood to mean small bubbles present in a high density.
[0168] Although small, these bubbles are not acceptable for SOI substrates that are so thin and therefore the bubbling was not measured in subsequent steps of the process for fabricating this SOI substrate.
[0169] Therefore, applied independently of one another, bonding in a partial vacuum and the bond-strengthening and cleaving anneal alleviate the bubbling effect after the cleaving process, but defects appear in subsequent steps, especially during the RTA treatment used to repair defects.
[0170] In other words, applied independently of one another, the bonding in a partial vacuum and the bond-strengthening and cleaving anneal simply seem to modify the bubbling effect, but do not allow it to be suppressed.
[0171] In contrast, combining these two treatments allows, at the end of the entire process for fabricating the SOI structure, a satisfactory level of bubbling to be obtained.
[0172] The sacrificial oxidation step carried out after the RTA treatment allows the useful layer of the SOI wafer to be thinned.
[0173] In the final SOI structure, the defectivity is measured in terms of defect clusters. The result of this measurement is called area count (AC).
[0174] A KLA Tencor SP2 inspection tool was used to make this measurement.
[0175] In this respect, the reader may refer to French Patent Number FR 2 911 429, published Jul. 18, 2008 (application number FR20070000192 filed Jan. 11, 2007) which describes a method and a system for detecting defect clusters.
[0176] Implementation of the process according to the invention allows an SOI structure having a defectivity, expressed in terms of defect clusters, of 60 or less, to be obtained.
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Embodiments of to invention relate to a process for fabricating a silicon-on-insulator structure comprising the following steps: providing a donor substrate and a support substrate, only one of the substrates being covered with an oxide layer; forming, in the donor substrate, a weak zone; plasma activating the oxide layer; bonding the donor substrate to the support substrate in a partial vacuum; implementing a bond-strengthening anneal at a temperature of 350° C. or less causing the donor substrate to cleave along the weak zone; and carrying out a heat treatment at a temperature above 900° C. A transition from the temperature of the bond-strengthening anneal to the temperature of the heat treatment may be achieved at a ramp rate above 10° C./s.
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[0001] This application claims priority from U.S. Provisional Application Ser. No. 60/818,435 filed on 3 Jul. 2006.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to the drilling industry and in particular to an apparatus, system and method of communicating with a downhole tool assembly.
BACKGROUND OF THE INVENTION
[0003] In the field of drilling it is frequently desirable to communicate with devices which are located at the downhole end of the drilling assembly. There are few variable parameters which are readily transferable from the surface to the downhole location or assembly and all of these suffer from shortcomings. Largely, the measurable variables in the drilling operation are; the flow of fluids through the drillstring, the amount of weight which is placed on the bit and the revolutions of the drillpipe.
[0004] This disclosure acknowledges that weight on bit and fluid cycling are limited in their range of data transmission as, inevitably, they are confined to being binary input parameters. These surface variable parameters can have a negative impact upon the drilling operation when used as means of communicating with downhole devices, as; either the transmission time is lengthened which serves to interrupt the process of drilling the well or the data to be transmitted is, of necessity, reduced in content.
[0005] Previous attempts to communicate via drillstring RPM were successful but compromised the efficiency of the drilling operation in that the frequencies of operation were recurrently related to a baseline of zero RPM. In rotary drilling zero RPM equates to a non-drilling state, in other words, in order to be able to communicate using RPM the drilling operation had to be arrested, resulting in poorer drilling productivity and less rewarding economics. The essence of the instant invention is that it allows the baseline incremental drillstring RPM to be established and then increases or decreases RPM transmission in order to create a carrier for the desired data to be transmitted, without arresting the drilling operation. Expressed differently the instant invention uses the nominal drillstring RPM to establish itself as a carrier and then deviates from this established norm by marginal amounts. Assuming that the nominal RPM has been established in order to optimize drilling efficiency, the instant method and apparatus thus represents the best opportunity for adaptive downlink telemetry with the least interference to optimized drilling parameters. Yet a further benefit of the invention is the amount of data which may be transmitted in a timely manner from the surface of the earth to a downhole device or devices located at the distal end of the drilling assembly.
[0006] It is an axiom of rotary drilling that if a single revolution of the drillstring is input at the surface then it must be transmitted to the bit. Failure of the revolution to “transit” to the bit means either a “back-off” (the drillstring unscrewed) or a “twist-off” (the drillstring broke in two).
[0007] In the past, the reason for the use of zero RPM as a marker is that it has a definitive null value, either of vibration, rotation or rate of rotation and is therefore an easily measurable state.
[0008] Prior art [ENGELDER, U.S. Pat. No. 4,763,258] METHOD AND APPARATUS FOR TELEMETRY WHILE DRILLING BY CHANGING DRILLSTRING ROTATION ANGLE OR SPEED contemplated the use of solid state sensors which monitored “angularly dependent geophysical parameters while rotating the drillstring” in order to communicate from the surface to the downhole device. Magnetometers and inclinometers were sampled and signals therefrom were conditioned, multiplexed, converted to digital signals and then processed. By alternating the RPM with zero RPM bands and by altering the RPM ranges, information could be communicated to the downhole device. The device was limited in that the processing power and sensor sample frequency which was available at that time was much slower than that which is available at the present time. The device required slow rotation of the drillstring in order to communicate from the surface of the wellbore to the downhole device. Although this methodology is feasible, the length of the drillstring, directional characteristics of the wellbore and physical attributes of the drillstring are all variables which will all affect the ability to accurately transfer information to the distal end of the drilling assembly, or, more specifically, to determine with any degree of accuracy, the ‘arrival-time’ of the information at the distal end of the drilling assembly. A further difficulty with this particular arrangement, as previously explored, is the requirement to stop the drilling process, which, in practice, necessitates lifting the bit from the bottom-of the wellbore resulting in additional lost productive time. This is particularly required when drilling using aggressive, high torque, PDC bits, due to the resultant amount of on-bottom torsional friction which is created.
[0009] More recent prior art [MOUGEL AND HUTIN G.B. 2,352,743, U.S. Pat. No. 6,267,185] APPARATUS AND METHOD FOR COMMUNICATION WITH DOWNHOLE EQUIPMENT USING DRILLSTRING ROTATION AND GYROSCOPIC SENSORS removed the requirement for the measurement of geophysical parameters, substituting the measurement of non-geophysical parameters in the form of inertial rate gyroscopes. This, later art, taking advantage of faster downhole processor times, also claimed the possibility of both binary and decimal communication modes. The removal of dependent geophysical parameters would be of particular use when communications with downhole devices are planned in a zone of magnetic interference or in operational usage where there are unpredictable results from conventional geomagnetic sensors such as in surface conductor drilling beneath offshore platforms.
[0010] Additional prior art [van STEENWYCK et al. U.S. Pat. No. 6,608,565] DOWNWARD COMMUNICATION IN A BOREHOLE THROUGH DRILLSTRING ROTARY MODULATION concluded that additional transmitted data density could be achieved by modulating RPM either between a base level of zero RPM and a certain pre-determined value of RPM or, alternately, by eliminating the zero RPM baseline indicator, between two pre-determined values of RPM, which would potentially allow drilling to continue during drillstring rotary modulation.
[0011] U.S. Pat. No. 6,608,565[van STEENWYCK et al.] proposes that two levels of modulation input are utilized to create “talkdown” waveforms. Talkdown is essentially a phrase describing information passed down to the distal end of the drillstring—“talkdown.” Relative pre-determined discrete rotation rates, (R 1 , R 2 ) (“RPM”) are measured downhole against time and the default device for talkdown is described as an MWD device. This invention, applies a well understood measurement-while drilling (“MWD”) form of binary encoding technique and methodology to the transmission of data from surface to downhole.
[0012] The specification provides illustration and constraint on the method in FIG. 1 and FIG. 10 , while the methodology of signal conditioning, processing and threshold identification and message capture of the downhole device is illustrated in FIGS. 5 through 7 .
[0013] The data is preceded by a “sync” word consisting of a pulse width with a rising edge, corresponding to an increase in RPM, a pulse of equal width which corresponds to a decrease in RPM with a message word which consists of two periods of increased RPM, with a single band of lower RPM between. This format is considered to constitute optimal transmission methodology with minimal disruption to the drillstring.
[0014] In the field of drilling and in particular directional drilling, there is found a phenomenon known as “stick-slip” which is caused by a variety of friction factors of the drillstring rotating within the borehole. “Stick-slip causes the tubulars which comprise the drilling assembly (drillstring) to react like a coiled spring—winding up and unwinding: the degree and severity of the acceleration and deceleration of the drillstring, when compared with a nominal baseline RPM determines the classification of the qualitative condition which can be largely described as being anything from “mild” to “severe.” “Stick-slip” of whatever nature is not a desirable by-product, either from the perspective of drilling dynamics and efficiency, nor from the negative affect which it has on drilling tools which are located in the lower component of the BHA.
[0015] Historically, it is evident that stick-slip is an element which is difficult to quantify. It is almost impossible to avoid or eradicate during normal rotary drilling. It is the intention of this disclosure to introduce a system which is capable of surface power input management which may serve to reduce some of the peak accelerations which are observed at the distal end of the drillstring. The effectiveness of this invention may be improved particularly if the drillstring surface power management control system is augmented by selected data indicating the real-time status of downhole rotary conditions and which is transmitted in a recognizable format from the downhole to the surface location. It is a goal of this invention to enable a reduction of and, dependent upon the severity of the borehole condition, potentially to eliminate stick-slip.
[0016] Stick-slip constituted a further constraint in the entire prior art examples. The complexity of stick-slip is such that any of the following may have an effect on the magnitude of stick-slip: borehole inclination, hole-diameter, drillpipe diameter, BHA length and component configuration, bit type, bit gauge, bit cutter types, formation type, formation bedding planes and drilling fluids. Stick-slip is most noticeable during drilling, i.e. has a comparatively low magnitude when rotating off bottom and it is the interaction of bit with the formation which apparently contributes heavily to the largest element of stick-slip.
[0017] Van Steenwyck, in 2003 [U.S. Pat. No. 6,651,496], “INERTIALLY STABILIZED MAGNETOMETER MEASURING APPARATUS FOR USE IN A BOREHOLE ROTARY ENVIRONMENT”, proposes a device for reducing the effect of stick-slip on instruments which are rotationally co-located within a drillstring. (Ibid. FIGS. 1( a ) through 1 ( d ) and provide diagrammatic examples of the influence of stick-slip on sensor output for sensors which are co-located within a collar mechanism which is being subjected to stick-slip forces.
[0018] [McLOUGHLIN, U.S. Pat. No. 6,847,304] “APPARATUS AND METHOD FOR TRANSMITTING INFORMATION TO AND COMMUNICATING WITH A DOWNHOLE DEVICE, proposed the superimposition of magnetic field(s) over the prevailing geomagnetic field, and constructed a means of transferring signal from surface, via the rotating drillstring, to a downhole electromechanical sub-assembly which incorporated a non-rotating portion as a component of a three-dimensional rotary steerable drilling device.
[0019] Acknowledging and utilizing the increases in downhole electronic sampling and processing power which had occurred since the ENGELDER Patent, McLoughlin proposed a frequency modulated approach to data transmission. During the prototyping phase of the downhole device explained in U.S. Pat. No. 5,979,570 to McLoughlin et al, SURFACE CONTROLLED WELLBORE DIRECTIONAL STEERING TOOL, industry professionals expressed concern that the communications methodology which is described in U.S. Pat. No. 6,847,304 to MCLOUGHLIN would be ineffective when communicating with a device located at the distal end of the drilling assembly.
[0020] Apocryphal reasons for this belief centered around drillstring properties; PAVONE, U.S. Pat. No. 5,507,353 METHOD AND SYSTEM FOR CONTROLLING THE ROTARY SPEED STABILITY OF A DRILL BIT notes “because the drill collar assembly is very stiff against torsional strain there is practically no speed difference between (the drill collars) and the drill-bit.”
[0021] The same cannot, however, be said for the drill pipe string, which typically comprises the greater part of the total length of a drilling assembly and which stretches between the surface of the Earth and the drill collar sub assembly. Drill-pipe is highly flexible and exhibits torsional harmonic vibration, or oscillatory behavior.
[0022] Drill pipe behavior under torsion is unarguably complex; DOMINICK, U.S. Pat. No. 6,065,332, METHOD AND APPARATUS FOR SENSING AND DISPLAYING TORSIONAL VIBRATION, offers a concise explanation of drillpipe behavior and the forces acting thereon:
“During drilling operations, a drillstring is subjected to axial, lateral, and torsional loads stemming from a variety of sources. In the context of a rotating drillstring, torsional loads are imparted to the drillstring by the rotary table, which rotates the drillstring, and by the interference between the drillstring and the wellbore. Axial loads act on the drillstring as a result of the successive impacts of the drill bit on the cutting face, and as a result of the irregular feed rate of the drillstring by the driller. The result of this multitude of forces applied to the drillstring is a plurality of vibrations introduced into the drillstring. The particular mode of vibration will depend on the type of load applied. For example, variations in the torque applied to the drillstring will result in a torsional vibration of the drillstring. At the surface, torsional vibration in the drillstring appears as regular, periodic cycling of the rotary table torque. The torsional oscillations usually occur at a frequency that is close to a fundamental torsional mode of the drillstring, which depends primarily on the drill pipe length and size, and the mass of the bottom hole assembly. (BHA)”
[0025] When it is considered that any drilling assembly has multiple vibration inducing variables acting thereon it is unsurprising that reservations were expressed as to the ability of the McLOUGHLIN communications method to adapt to a wide variety of drilling scenarios. However the simple observation behind this patent concept was that if, at the surface of the earth, a million revolutions are input into the drillstring and subsequently a million revolutions are not delivered to the distal end of the drilling assembly, then communications will not be the issue—there will be more pressing problems with the drilling assembly. Largely then, the effectiveness of this method of communications protocol is determined by ‘when’ the revolutions which are input at the surface of the earth are delivered to devices located at the distal end of the drilling assembly, i.e. timing.
[0026] In view of the novelty of the communications format, the lack of field experience and the criticality of the application, it was determined that optimal chances of success would occur if data sets were separated, one from the other by “null” data sets, otherwise referred to as “data-gaps”. Gaps were defined by reducing the drilling RPM substantially, either to zero, i.e. non-drilling or below a rotational threshold speed at which drilling would be severely compromised. In practical applications of this patent, all communications protocols were designed with ‘null’ interpolation as illustrated in FIGS. 3A and 3B of U.S. Pat. No. 6,847,304. This format is still in use today.
[0027] Despite successes with the McLOUGHLIN method of rotary communications, this approach, as with earlier devices, leaves the drilling process compromised as rotation has to stop on at least one occasion per data (point) transmission sequence or “data set” in order to provide a baseline or relational marker for the data transmission to occur.
[0028] With all the examples of prior art cited herein, it is evident that a more sophisticated or detailed data downlink will result in a longer transmission time with a corresponding increase in the potential for data corruption or transmission failure between the surface and the distal components located in the bottom hole assembly. The instant method and system proposes an improved methodology for increasing the range of data transmitted from the surface of the earth to sensors located at the distal component of the drilling assembly without increasing the risk of transmitting corrupted data.
[0029] The McLoughlin prior art considered that microprocessor speeds were sufficient to overcome the limitations in earlier devices and that the actual drillstring RPM could be monitored by sensors which had higher data acquisition rates than had been available in the past, such that the actual instantaneous RPM could be monitored and used as an integer in the transmission of data to the downhole location.
[0030] Field experience of this mechanism and methodology proved that the microprocessor speed was sufficient to keep up with drillstring RPM in excess of 300 RPM. Field experience also proved that, even with severe stick-slip, the device was capable of transmitting RPM to a very small window of accuracy, such that the required toolface accuracy could be transmitted within less than 3° tolerance, corresponding to an ability to read within ±2 RPM. In field trials and in commercial deployment, this format, incorporating null data blocks was always used, typically with a reported 2σ or 95% first time success ratio.
[0031] The mechanism was also able to compensate for stick-slip by monitoring real-time revolutions such that the revolutions were measured against a time baseline and averaged over a given, pre-determined period. Given the requirement for absolute certainty in the application of three-dimensional direction trajectory control, a preamble was added to the transmission sequence to ensure that no command sequences were inadvertently transmitted to the downhole device.
[0032] The invention was limited in scope as the preferred downhole target device was a non-rotating stabilizer specified in McLOUGHLIN et al U.S. Pat. No. 5,979,570 SURFACE CONTROLLED WELLBORE STEERING TOOL and further in U.S. Pat. No. 6,808,027, WELLBORE DIRECTIONAL STEERING TOOL. This constrained the practical application of U.S. Pat. No 6,847,304, as its application was limited to devices which had non-rotating sleeve characteristics. The device was, additionally, constrained in that it was unidirectional in nature and did not contemplate confirmation of the transmission receipt from the downhole device. The lack of a confirmation response meant that the talkdown protocol had to be infallible in order to gain commercial acceptance. The critical requirement for absolute certainty of data transfer from the surface location to downhole meant that sample times were extended which provided constraints to the economic viability of the method and device in terms of the amount of data or data density which could effectively be transmitted from the surface of the earth to the downhole device.
[0033] Prior art, individually and collectively, thus envisaged simple, single phase, transmissions, incorporating periods of ‘zero’ rotation, even when frequency modulation was contemplated.
[0034] Thus, there remains a need to provide an adaptive system to communicate with devices located at the distal end of the drilling assembly that is devoid of “zero” rotation time periods and effective when stick-slip and other complications in the drilling process are present.
SUMMARY OF THE INVENTION
[0035] The instant invention seeks to mitigate and avoid the problems described above through the use of an adaptive protocol which is an object of the instant method. At a minimum the instant method proposes an adaptive system of communicating information from the surface of the earth to a device located downhole. A further object of the invention is the optimization of the drilling process as the talkdown protocol will adaptively fit around the existing drillstring RPM. A further economic benefit is that with this adaptive system the ΔRPM Offset between the optimized drilling condition and the RPM required for data transmission can be monitored and adjusted in real-time, resulting in less disruption to the drilling process. This, effectively, constitutes real-time downhole calibration.
[0036] Prior art did not allow for adaptive program sequences to be transmitted from a surface to a downhole location, whereas the instant device considers that the ability to work from a variable baseline which is related to optimal drilling RPM and which is established and quantified in real-time is a fundamental improvement to the “talkdown” process. For example, a bit may drill a certain formation more effectively at a particular RPM range; thus alterations in the formation being drilled may result in a requirement to alter the RPM many times in the course of a single bit trip in order to (re)optimize the drilling process, indeed, it may be altered within the time or distance drilled within a single joint of drillpipe. The instant method and device is therefore adaptable to work from a baseline which is variable and which is configured in real-time either from information gained from instrumentation which is rotationally co-located within the bottom-hole-assembly (“BHA”) and which is transmitted back to surface, or from observation of surface RPM input without additional data transmission from downhole devices and without the need to arrest the drilling process to create a new baseline. Thus, the instant method can be integrated with existing downhole technologies or may act as a stand-alone method of communicating with any downhole device.
[0037] Additionally, the instant invention considers that surface to downhole transmissions which are adaptive is a desirable and important feature of the instant art form. That is to say that in addition to being able to utilize a baseline or datum RPM which is variable in furtherance of optimized drilling parameters, the duration (timing) and offset (ΔRPM) are themselves adaptively variable. Knowing that drilling parameters and in particular RPM, may be altered for a variety of reasons and at many times during the well drilling process and considering that drilling parameters are optimized for economic reasons, it is desirable to minimize the “delta offset” (ΔRPM) which is used in transferring information from the surface to the bottom of the borehole as any delta RPM offset (ΔRPM) corresponds to adoption of sub-optimal drilling parameters. It is also desirable to minimizing the time taken to transmit data sequences to a downhole device, as this results in the potential for greater surface to downhole transmission data density.
[0038] The instant device and method contemplates an adaptive way of arranging rotary command sequences to obtain optimal encoding with minimal disruption to the drilling process. Within the scope of this method it is possible to incorporate single-phase, bi-phase, or, for preference, multi-phase data transmission, subject to the requirements of the particular well profile, surface and downhole tool configurations and required data transmission density.
[0039] An important element of the invention is a significant increase in the data density which can be transmitted to the downhole device using this equipment and methodology when compared to prior devices. The result is superior communications between surface the surface of the earth and downhole device(s), with the potential for a more integrated and adaptive approach between the surface and downhole sub-systems. Indeed, it is envisioned that the versatility of this adaptive protocol would enable multiple downhole devices, co-located within a single drillstring to receive information, data or commands, in a timely manner, without compromising the efficiency of the drilling process.
[0040] Additionally, the instant method provides a viable possibility of surface to downhole transmission of real-time depth which is of incalculable value in drilling complex well profiles as it allows trajectories to be preprogrammed into downhole tools which can then be acted upon once the required depth is achieved. This allows sophisticated adjustments to be made to the wellbore trajectory without additional intervention from surface.
[0041] Other data to be transmitted may include instructions to a downhole device on alterations to its internal configuration or geological or other marker bed information or any other piece of information which is of practical use to downhole devices. Thus, the instant method and device may be used to adapt any downhole device or devices to changing requirements of the drilling environment and instruct about events which pertain to its/their internal mechanisms, or to convey information pertaining to the external environment which are outside the measurement ability of downhole sensors and thus enhance the capabilities and economic effectiveness of existing devices. Data may be quantitative, or qualitative in nature.
[0042] Therefore, this method will allow almost continuous transmission of information between the surface of the earth and the downhole drilling device, with very few additional mechanical or electromechanical components being required and with minimal alteration to the selected ideal drilling parameters. As a further economic benefit, it is possible to configure existing downhole systems which are equipped with the appropriate sensors to receive information by adding software protocols which can decode the information which is being transmitted, for example downhole instrumentation telemetry packages.
[0043] A further benefit which accrues if existing downhole telemetry package sensors are utilized is the ability to obtain confirmation of receipt of transmission from existing MWD/LWD downhole components in the form of pulse telemetered messages. In this way the adaptive protocol may be optimized during the drilling process without loss of drilling time. If the MWD/LWD components also telemeter quality of transmission the time taken for subsequent data transmission frames will be optimized in terms of duration and offset as the particular well environment is assimilated and acted upon
[0044] Although, as practical field application of the McLoughlin Patent (U.S. Pat. No. 6,847,304) proved, it is possible to pass rotary command sequences from surface by manually altering the rotary speed of the drillstring, for ease of use and practical applicability, the instant patent proposes the use of a software controlled hardware interface between the operator and the surface rotational motive means of the drillstring, although any suitable interface may be used without departing from the spirit of the invention
[0045] Thus, a more sophisticated adaptation of the proposed method and apparatus would integrate a surface control system with the rotary drillstring motive means. By this method, human error is removed from the physical downlink protocol. The apparatus would, ideally, comprise an electromechanical interface between operator and the drillstring, which would have the ability to control the rotational speed, ΔRPM offset of the drillstring rotational speed and duration of maintaining the offset. It is within the objects of this patent to substitute different surface RPM control means while remaining within the scope of this patent.
[0046] The interface can be used whether the rotary motive means is a topdrive or a more conventional rotary table.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] FIG. 1 shows a schematic of a downhole sensor showing idealized rotary speed output at the distal end of a drilling assembly.
[0048] FIG. 2 shows a more typical downhole sensor output, depicting uneven rotary speed typical seen drilling
[0049] FIG. 3 shows downhole sensor outputs when more severe stick-slip is present
[0050] FIG. 4 shows a focused view of a stick-slip outputs and points of interest for transmission back to the surface of the earth.
[0051] FIG. 5 shows a simple encoding sequence for transmission of large amounts of data from the surface of the earth to a downhole device illustratively using three contiguous hexadecimal data frames.
[0052] FIG. 5A shows the simple encoding sequence illustrated in FIG. 5 , using three hexadecimal data sets, for simplicity, broken out into its constituent components
[0053] FIG. 6 shows a simple encoding sequence using three hexadecimal data frames indicating a less than optimal data transmission frame.
[0054] FIG. 7 shows a method of rearranging data transmission frames to optimize data transmission by continually causing the baseline of the transmission to migrate in order to mitigate large variations in ΔRPM over a short time interval,
[0055] FIG. 8 shows a schema whereby block transit times are modified by extending the data frame to optimize data transmission by extending the ΔRPM offset time in order to enhance downhole sample quality.
[0056] FIG. 9 shows a preferred schema for encoding information where the position of the numerical values of data to be transmitted are varied within their data frames in accordance with pre-determined, yet adaptive, protocols.
[0057] FIG. 10 shows a schematic illustrating a potential surface control system for insertion into a conventional drilling rig assembly including optional pulse telemetry feedback loop.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0058] In one embodiment the device constitutes a surface computer equipped with an interface to the drilling rig rotary drive which contains information for encryption and transmission to the downhole instrumentation package. Any downhole device which is to receive information is equipped with a similar decryption program protocol to facilitate effective transfer of information between the surface location and the downhole device or devices. The surface computer monitors the existing baseline drillstring rotational speed in order to establish a datum from which to modulate the rotational frequency in order to encode the information to be transmitted. The program variables' sophistication, including timing and ΔRPM offsets are variable and adaptive, depending on the application, information to be transmitted and specific well environment and requirements. The surface computer is equipped with a real time clock interface which during program sequencing causes the mechanical interface to temporarily override the existing baseline rotational speed being input into the drillstring within pre-determined yet adaptable time limits. The over-ride, or ΔRPM offset, may be positive, representing an increase in drillstring rotary speed, or negative, representing a decrease in drillstring rotary speed.
[0059] The surface control of the drillstring rotation incorporates not only RPM control, but “ramp” profiles, i.e. the speed with which RPM is gained and lost from the drillstring, alternatively expressed as drillstring rotational acceleration and deceleration.
[0060] The management of the “ramp-profiles” forms an additional means of transmitting information, whereby the slope of gain, meaning the increase in RPM per n time period and conversely the slope of RPM loss, meaning the decrease in RPM per n time period may in and of themselves constitute a segment of the information to be transferred, or, alternatively may comprise a differentiator between different types of data to be transmitted to components located at the distal end of the drillstring.
[0061] Such computer controlled surface assemblies are functionally desirable as they constrain drillstring acceleration and deceleration within acceptable limits. Drillstring wear is exacerbated when rapid acceleration and deceleration are present.
[0062] In addition, the simplicity of the surface system hardware and versatility of the surface system software allows for more accurate timing of events and for error free adjustment of the protocol timing as required.
[0063] It is another object of the present invention to provide an adaptive system which can compare the observed surface drilling condition with the reported downhole drilling condition.
[0064] In one embodiment of the present invention, synchronization of the surface and downhole devices is accomplished by simple comparison such that when a pre-determined and absolute number of drillstring RPM have been input at surface and received downhole, both surface and downhole instrumentation are taken to be zeroed. For example, following a connection in the drilling process, the pumps are turned on and the rotary speed is increased from stationary to a desired number of RPM. In a preferred embodiment of the device and in compliance with standard drilling practices the addition of a length of drillpipe provides an evident starting point for a bi-directional communications protocol, although the communications protocol may be started at any other appropriate point in time. In order to add a length of drillpipe, the drilling pumps have to be switched off, flow is reduced to zero, internal drillpipe pressure is reduced to hydrostatic pressure and, typically the rotary table has to remain stationary for a period of time. This sequence of events is easily tracked by downhole devices and used as a convenient marker for subsequent events. Following the addition of an additional length of drillpipe, it is usual to take a directional survey in order to ascertain the latest position and directional tendencies of the wellbore. Recently, this has also become common practice on vertical wells and is therefore an appropriate starting point for synchronizing surface and downhole systems on the majority of wells.
[0065] Directional surveying is typically accomplished by MWD survey techniques. Prior to the MWD transmission the pumps are switched on. Immediately following the MWD directional transmission, the bit is placed back on bottom and drilling re-commences. At surface, when, for example, 100 revolutions of the drillstring have been made or any number which is easily detected using one of a variety of well understood methods, the surface system clock and the downhole instrumentation clock(s) are zeroed. All timing inputs until the next period when the drillstring rotation stops are now referenced to this point in time. In a similar manner, the downhole tool detects 100 revolutions of the drillstring in a manner which is easily understood, using one or more of a variety of commercially available sensors and its internal clock mechanism is likewise zeroed. It can be easily understood that, although there are slight timing variations between surface input of RPM and downhole output of RPM that these differences are minimal when considered in a contextual timeframe.
[0066] To facilitate the mud-pulse telemetry transmission of downhole rotational characteristics, the downhole angular acceleration or vibration is monitored by sensors which are located within and comprise a standard component of the downhole MWD device as previously described.
[0067] That is to say, in order to proceed with the instant method with minimal disruption to the drilling process, an ideal method for any communication cycle may proceed as follows:
(a) Establish normal MWD directional communications in accordance with standard industry protocol (b) Re-establish normal drilling operations, incorporating flow, RPM and weight on bit. (c) Optionally transmit via MWD, measurements pertaining to the distal rotational characteristics of the drillstring, as previously indicated, (preferably post transmission of the full survey directional data) in a time frame which will allow the cyclic pattern of drillstring harmonic vibration under existing drilling conditions to become established, (d) Optionally, receive the information transmitted in (c) above at surface and adapt the surface to downhole telemetry as required. (e) Transmit information from the surface of the earth to a downhole location in an optimized format which is compatible with the observed conditions downhole, pre-programmed data, information and protocols to components co-located at the distal end of the drilling assembly (f) Optionally transmit modified information from the surface of the earth to a downhole location in an optimized format, as specified in (e), above, and which takes into account information derived from the optional downhole feedback mechanism examined in (c) and (d), above.
The above mentioned schema comprises a preferred method of operating the downhole adaptive section of the device and method which largely complies with standard operational procedures, but is not intended as a constraint on the scope of the invention.
[0074] Any appropriate sensor can be utilized in order to measure revolutions of the drillstring in the downhole environment. However, as no direct azimuthal or vector rotational measurements are required and the entire sensor requirement is to be able to detect rotation, a simple, inexpensive sensor type should suffice. (This could include MEMS type sensors.) Thus at the distal end of the drilling assembly, the nominal surface input RPM may be directly measured by counting discrete RPM events over a given time period, may be calculated from vibration data or, alternatively, may be a contained within a message sent from surface using the instant protocol.
[0075] In the case of direct measurement, measurements are taken as required in order to derive a point of peak amplitude which corresponds to a defined point in a single rotation. It is evident that the high side of the hole, or, is preferable as circumferential a markers, however any appropriate point or points may be utilized. In near vertical wells where it is difficult to define “high-side” it is common, to magnetometer as a measurement device, using magnetic north as an identifiable indexing point. Unlike traditional survey applications where quantitative sensor data output is required, in this instance only qualitative data is required, referenced to a downhole clock timing circuit. For preference, peak samples are obtained. Raw sample data may be averaged and filtered to provide an output curve. Even with vibrational interference rotation monitoring and RPM “centering” will be possible. There follows an illustration of sample timing as measured against potential peak RPM:
[0076] Where RPM=300
[0077] Drillstring RPM=5 Revolutions per second.
[0078] Sampling at 256 samples/sec=51.2 Samples/Revolution
[0079] Detecting an arc of 30°, i.e. 15° either side of a known peak point.
[0080] This is easily within the scope of sample range provided by existing downhole technologies.
[0081] The downhole device is equipped with memory in which to store the peak measurements of each sensor which are of interest [See FIG. 4 .] This part of the memory may be translated into encoded data for transmission to surface via conventional mud pulse telemetry, or wireline, or any other means such as via a specially modified drillstring.
[0082] The sensor outputs are then logged against time to indicate relevant features of the downhole baseline rotational speed, thereby creating a profile against which to measure ΔRPM offsets. In an idealized transmission, stick-slip would play a minimal or non-existent part in the communication protocol. In a preferred mode of operation, once the existing downhole environment is reported back by MWD telemetry, the surface system may adaptively transmit data by a protocol which gives the best possibility of successful data transmission. The optimal transmission timing is one which provides the highest degree of certainty of a successful transmission combined with the shortest transmission time.
[0083] FIGS. 1 through to 4 illustrate some of the rotational characteristics which are likely to be observed by sensors located at the distal end of the drilling assembly. FIG. 1 illustrates a diagrammatic embodiment of downhole records for one minute of idealized drilling conditions at 120 RPM, where there would be 120 revolutions registered in memory at precisely 0.5 second intervals. The reader is referred to FIG. 1 . This represents a schematic of the downhole sensor measurement of RPM. Peak amplitude of a sensor output is represented by the horizontal line marked ( 11 ). Each individual vertical line represents a single rotation of the drillstring ( 12 ). Traditionally “high” side of the borehole will be selected as an identifiable indexing point from which to reference sensor orientation, but any other index point, relating to either the wellbore or the orientation of the instrumentation itself, may be used with equal utility. It should be noted that the RPM timing in this idealized sequence shows the index point of each revolution occurring at exactly equal time intervals. In this example the frequency of the measured index points are 2.0 Hz.
[0084] FIG. 2 illustrates a similar, but suboptimal example where the 120 RPM will “arrive” at the downhole location at unequal times: in an extreme example the drillstring acceleration may result in the total RPM count momentarily exceeding 120 RPM. Drillstring peak amplitude ( 21 ) is labeled as is the lower marker ( 22 ). The sum total of revolutions per period is identical between surface and downhole, thus, for every increase above baseline RPM, there is an equal and corresponding decrease in RPM. The instant device is capable of differentiating the rotational transit features using any statistical means in order to derive meaningful quality of baseline RPM data.
[0085] FIG. 3 illustrates an even more extreme example of unwanted stick-slip measurements made at the distal end of the drilling assembly, where there are periods where the drillstring actually stops rotating for a period of time ( 35 ). This is followed by corresponding and proportional peak amplitude rotation increases ( 33 ) which take place over another measurable time increment ( 32 ). Surface input RPM is noted ( 34 ) and is equal to RPM Average ( 30 ).
[0086] A timeline ( 31 ) is established in seconds, against which RPM is measured. It will be observed that the peak amplitude RPM ( 32 ), defined as RPM events ( 33 ) which exceed the average RPM ( 30 ) have rotational measurements which are more closely grouped than the lower amplitude RPM ( 34 ). One component which is visible as a result of the measurements which are made is the ability to identify periods of no-rotation at the bit ( 35 ). The benefit of having this real-time information is to allow modulation of the input power from surface in order to diminish the unwanted effect of extreme stick-slip. Taking advantage of the benefit of bi-directional communications, this condition would be visible to the operator at surface. Thus the degree of severity of stick-slip will be understood and adjustments to surface RPM can be made in order to provide a less erratic baseline RPM from which to offset communications transmissions.
[0087] If the data which is received at surface indicates that the RPM Interrupt interval ( 35 ) or the RPM-Peak value [ FIG. 3 , ( 32 ) and ( 33 )] are excessive and would potentially cause poor data transmission, then the surface system will modify the RPM in order to bring these values within acceptable ranges prior to commencing data transmission. Adjustments to the surface RPM may take the form of rhythmic or arrhythmic acceleration or deceleration of the drillstring in such a way that the RPM interrupt shown at FIG. 3 ( 35 ) is diminished. A further advantage of this method, known by practitioners of the art, is that reduction of the condition of stick-slip typically results in increases in drilling penetration rate and improved drilling economics.
[0088] FIG. 4 shows some of the variables which could be transmitted via MWD telemetry to surface in order to optimize the baseline RPM at the distal end of the drilling assembly. All measurements from the distal end of the drillstring are measured in relation to an average established surface baseline RPM ( 40 ) (“RPM-Avg”) expressed in RPM.
[0089] Indicators of distal variations from the surface input RPM may be transmitted as indicated in FIG. 4 : time between baseline to baseline peak amplitude, ( 41 ), time between baseline to baseline trough amplitude, ( 42 ), ΔRPM offset below the baseline RPM, ( 43 ), ΔRPM offset above the known baseline RPM, ( 44 ) and the slope of the ΔRPM offsets from baseline RPM ( 45 ), ( 46 ). It is within the scope of the invention to transmit the nominal surface RPM to the downhole device thus reducing the requirement to telemeter large numbers and allowing for delta offsets to be transmitted using pulse telemetry methods. It is also within the scope of this invention to make any other appropriate sensor measurements pertaining to rotation, whether of a geophysical or non-geophysical nature, however quantified, for the purposes of reducing the effect of drillstring harmonics of the distal end of the drilling assembly. These measurements may be recorded downhole, constitute raw or processed data and be encoded for transmission to surface via pulse telemetry or any other means.
[0090] Information being transmitted to surface enables real-time manual or automated decisions to be made which allows for variation of the drillstring surface input torque in order to optimize the BHA response with respect to stick-slip. Prior art, MACDONALD, U.S. Pat. No. 6,732,052, METHOD & APPARATUS FOR PREDICTION CONTROL IN DRILLING DYNAMICS USING NEURAL NETWORKS and DOMINICK, U.S. Pat. No. 6,065,332, METHOD & APPARATUS FOR SENSING AND DISPLAYING TORSIONAL VIBRATION focus on the MWD transmission of qualitative data, and surface display, typically in the form of warning flags when dangerous levels of shock, vibration, acceleration and deceleration are measured. The instant device and methodology represents an improvement over prior art as it transmits quantitative information with which to make decisions enabling effective alterations to be made to the surface drillstring torque input characteristics, with the goal of reducing unwanted drillstring harmonic vibrations.
[0091] The data transmitted from the surface is measured by sensors located within the distal component of the drillstring and is assessed for quality. The quality acceptability criteria are then transmitted to surface, where the adaptive surface system takes the appropriate measures to determine improvements to the frequency, i.e., timing and ΔRPM offset of the data set to be transmitted in order to enable the optimal data downlink quality format to be selected.
[0092] FIG. 5 illustrates a surface to data transmission format incorporating hexadecimal coding. A hexadecimal coding base constitutes a preferred transmission format as it has the advantages of creating data frames which comprise a 4×4 matrix: that is to say, each data frame is 4 time periods in length, with four potential RPM variations from the established drilling baseline within each time frame. It should be understood that any base format of encoding is within the scope of this invention. The coding base itself may be a field variable and an adaptive component of this invention. [0081] The data transmission examples shown in FIGS. 5 , 6 and FIG. 9 , which constitute a preferred embodiment of encoding, illustrate positive RPM communications shifts of +1 nRPM and +2 nRPM and negative RPM communications shifts of −1 nRPM and −2 nRPM RPM. It is envisaged that 10 RPM represents an optimum for each shift from the established baseline; thus the shifts illustrated in FIGS. 5 , 6 and 9 represent deviations of +10, +20, −10 and −20 RPM from an established drilling RPM baseline. It is within the scope of this invention to utilize any delta RPM offset variation or use asymmetrical delta offsets within a single transmission frame. These figures assume that the drilling RPM—and thus drilling economics—has been optimized and that any communications variations are minimized in order to retain optimized drilling penetration rates.
[0093] The coded information may be preceded by a preamble or synchronization word which is used selectively as a data discriminator, data format identifier, identifier for a target device or initiating trigger for the data sequence. An alternate use for a preamble may be to incorporate multiple information sets within a single transmission sequence. Thus, for example, in a preamble which is to be followed by data to be transmitted to a 3D-rotary steerable system the preamble may indicate that the first data frame contains information on the degree of dogleg severity to be selected, and the second data frame contains concerning required toolface direction to be communicated. Of course, in many LWD systems there is a common system bus which obviates the need for identification of a target device, the instruction is then sent to a central “receiving” sensor located within a downhole instrument package and “forwarded” to the individual device which then takes the appropriate action.
[0094] A further method of discriminating the contents of data frames might be to increase or decrease the baseline over a specific period of time, resulting in a trapezoidal RPM variation shape, rather than the idealized square wave variation shape which is illustrated in FIG. 5 through to FIG. 9 . For example, increasing the RPM over n period by ×RPM might be an indicator that the data set following the particular “ramp” profile contains a specific type of information which may then, for example, be directed to a particular downhole device or used to set in motion logical processes within devices located at the distal end of the drilling assembly.
[0095] In FIG. 5 , a rotary speed baseline has been established for drilling a certain formation at 120 RPM. A timeline is included to illustrate the nature and timing of the data transmission from surface. Data in this example is to be transmitted in three (3) discrete data sets, [ FIG. 5A , ( 52 ), ( 54 ), ( 56 )] Data frame ( 52 ) contains integers 0 to 15 “n1” which occur in time intervals t 1 and t 2 ; subsequent data frame ( 54 ) contains integers from 16 to 256, incremented in ‘16's’, “n16”, which occur in time intervals t 3 and t 4 and the third and final data frame of this example ( 56 ) contains integers from 272to 4,112 incremented in 256's, “n256” which occur in time intervals t 5 and t 6 . In this way a maximum decimal data value of 4,383 may be achieved using three complete data frame. It is feasible to add an additional half-data frame t 7 , (not illustrated), which would increase the transmitted number maximum to 37,423, which is ample for transmission of real-time depth to a downhole location. Addition of a further data frame t 8 , (also not illustrated) would increase this to 70,191. It is envisaged that the optimized transmission of data blocks t 1 through to t 6 will take three minutes, although in an environment which is substantially free from stick-slip this may be reduced. Thus, the instant invention constitutes an improvement over prior art in that the amount of data which may be transmitted over a specified time period is exponentially greater than the existing art and has the added benefit of not interrupting or compromising the drilling process. The data frames shown here may be arranged in any order, the ones in this example being purely for illustrative purposes. That is to say that within each data frame the numbers may be arranged differently, and the order in which they are received (n 1 , n 16 , n 256 ) may be reversed or arranged differently from the frames shown in this figure.
[0096] The versatility of the system and method also allows for each data frame to have a different format and for multiple, semi-continuous data frames to be sequentially added, thus “preamble, n1, n16 n1, n16, n256, n1, n16 n1, n16, n256 . . . ”.
[0097] The data which is to be transmitted, using the instant method may be numerical, encoded or encrypted and it may be transmitted to a single or multiple tool types within an individual drillstring.
[0098] It is within the scope of the invention to include safety, parity and error-checking blocks such that errors in data transmission are minimized. These are not explored in any detail here but are well known to those versed in the art of downhole drilling and communications.
[0099] The downlink illustrated in FIG. 5 , uses hexadecimal format. The number which is being transmitted from surface is decimal ‘1713 and is an encoded representation of any data which it is advantageous to transmit from the surface of the earth to a downhole device’. In the preferred hexadecimal encoding format shown in this and subsequent illustrations, this equates cumulatively to 1+160+1552. Data is extracted from downhole measurements made at the points labeled ( 51 ), ( 53 ) and ( 55 ). FIG. 5A shows the idealized data transmission sequence with ( 52 ), ( 54 ), ( 56 ), representing the formulae for the data set. In this example and starting with Data set 1 : a “1” is transmitted. In this illustrative example, the transmission is made by increasing the rotary speed of the drillstring by 20 RPM over the established baseline rotary speed for a pre-determined period and then returning to the baseline. The second data set transmits a “160”. This is accomplished by reducing the rotary speed of the drillstring below the established baseline rotary speed by 10 RPM ( 53 ). The final data set is “1552”. This is transmitted by increasing the rotary speed of the drillstring above the baseline rotary speed by a value of 10 RPM ( 55 ), ( 56 ), or, expressed differently, by increasing the RPM by 20 RPM over the baseline established at ( 53 ). It will be evident that the selected characteristics of increasing/decreasing RPM to transmit information, once established, should remain unaltered until completion of a specific data set or until a new baseline RPM is established. As previously discussed, events such as making a connection, or the transmission of a new “synchronization” word may usefully serve as data transmission boundaries. There is thus no need to trip the drillstring to surface in order to alter the downhole protocol format. Points labeled ( 57 ) indicate maximal values for specific data sets using this particular, hexadecimal, schematic.
[0100] A further variation to this schema is that within each discrete data set, once the data has been transmitted, the RPM does not return to its original baseline, but continues along the data point ( 51 ), until the end of that data set, i.e. the end of t 2 , t 4 or t 6 , respectively. The advantage to this method is that the downhole processor has a longer sample time from which to sample and extract the data. At the end of t 2 , ( 58 ), for example, the RPM returns to the baseline. In this example, given that each data block is 1 minute in length, this would mean that the numerical value ‘1’ is decoded from information received over a 45 second time period. This is illustrated by the heavy dashed line in FIGS. 5 and 5A ( 59 ) The ‘return to zero’ method is effective and self-checking, enabling continuous timing re-calibration.
[0101] FIG. 6 shows a further example where, due to the positioning of the data blocks within the matrix, there is a Δ4n offset between contiguous data sets. The decimal number which is being transmitted in this example is 3,418. The A 4 n offset occurs between the transmission of the value “64” in the second data frame and the transmission of the value “3,344” in the third data frame. Although the first Data Set has sufficient ‘recovery’ time to return to its baseline rotary speed, the large ΔRPM differential between the second and third Data Sets is, potentially, problematic. In the schema which is shown in FIG. 6 , the proximity of the data sets within consecutive data frames, t 4 and t 5 in conjunction with a Δ4n offset, presents a time constraint for the length of each data frame as the RPM has to return to a baseline within a time which does not compromise sensor sample frequency or decoding of information at the distal end of the drilling assembly data. It is clear that the rotary speed acceleration and deceleration depicted in FIG. 6 are idealized. Practical field applications show acceleration and deceleration of the rotary speed taking a trapezoidal (rather than square wave) format, ( 61 ), ( 62 ) due to surface equipment and drillstring limitations. Rapid acceleration and deceleration of the rotary speed of the drillstring, particularly over large RPM offsets, is undesirable. Large delta offsets in RPM between contiguous data blocks have the effect of reducing the data sample frequency within a time frame as shown at ( 63 ). However, another advantage of the invention over prior art is that acceleration and deceleration is restricted to a narrow ΔRPM offset bandwidth, rather than the entire available range of drillpipe rotational speeds. This in turn increases the sample frequency and improves the effectiveness of a data transmission. An alternative is to extend the time frames, t 1 , t 2 , etc., however, this is undesirable as the time taken to complete data transmission is extended, resulting in diminished data transmission efficiency.
[0102] FIG. 7 and FIG. 8 detail two potential methods for mitigation of potentially problematic rotary speed acceleration and deceleration ramps caused by large ΔRPM offsets. FIG. 7 illustrates the transmission of the same number, in FIG. 6 , i.e. “3,418” as There are two key differences between FIGS. 6 and 7 : firstly, in FIG. 7 , the number to be transmitted is defined by the upper, ( 71 ) and left, ( 72 ), edges of the data frame in the case of a positive ΔRPM offset and by the lower, ( 73 ) and left ( 74 ), edges of the data frame in the case of a negative ΔRPM offset and secondly, the sample time is extended to the end of each data set, ( 75 ). Additionally the Δ4n offset between contiguous data sets, t 4 and t 5 , has been removed. The Δ4n offset is mitigated by re-apportioning the Δ offset to +3n and −1n and then raising the baseline of each adjoining data set incrementally. Although this does not increase the sample timeframe used for transmission of the number “64”, in the second data set, the delta RPM offset between time frames t 4 and t 5 is reduced from Δ4n to Δ1n, which reduces the criticality of drillstring acceleration and deceleration and also increases the effective RPM sample window which has a positive affects on data transmission.
[0103] It is evident that incrementing the baseline in the manner illustrated in FIG. 7 , data set 2 and data set 3 should occur within the constraints of the drilling rig rotary drive. These constraints include operational maxima and minima. Thus, although the problem of large ΔRPM offsets is overcome, there is potential for this protocol format to extend beyond the effective upper range of the drilling rig rotary drive and caution should be exercised.
[0104] FIG. 8 shows the relevant portion of an alternate schema where the upper ( 81 ) and right edges ( 82 ) of the data frame are used as data defining borders. This mitigation schema occurs because, the target number ‘64’, is at the right hand border of data set t 4 which is followed by the target number ‘3,344’a data point occurring in the first column of the data set t 5 . It is clear that the number ‘3,344’ cannot be delineated in any other fashion than to use the leading (left-hand) ( 84 ) and lower ( 83 ) edges. Wherever the ΔRPM offset is large de-coding may be difficult, so a double length data set may be contrived to assist in providing quality improvements to the communications process.
[0105] Thus, according to FIG. 8 , the defining ‘edge’ of each target number within its data set is the upper edge ( 81 ) and the right edge ( 82 ) in the case of an increasing RPM (+ΔRPM) transmission and the lower edge ( 83 ) and the left edge ( 84 ) in the case of a decreasing (−ΔRPM) RPM transmission. It is within the scope of this invention to apply any other variation of RPM boundary definition to the data transmission with the object of increasing the probability of successful data transmission. In case of transmissions which occur in an extreme, “noisy”, environment, the timing windows can be increased. This would be accomplished adaptively and without the need to trip the BHA for reprogramming of downhole elements of the drillstring.
[0106] FIG. 9 shows a further variation and preferred method for adapting the data sets to optimize transmission success. This Figure takes, as an example, the standard data format depicted in FIG. 5 through to FIG. 8 , although the number of data sets may greater or lesser, dependent upon the data to be downlinked. FIG. 9 illustrates the transmission number “3,542”.
[0107] In FIG. 9A , the number 3,542 corresponds to the highlighted blocks: data set 1 =“6”; data set 2 =“192” and data set 3 =“3,344”.
[0108] From FIGS. 6 and 7 , it was observed that the greatest potential problem area for successful data transmission occurs when there are contiguous data sets of single time period duration which are followed immediately by a ΔRPM alteration in the first time frame of the next data set. Effectively, at the distal end of the drilling assembly, this does not allow sufficient stabilized RPM data acquisition time while also guaranteeing effective transmission. FIG. 9A illustrates one such potentially sub-optimal data transmission: in this example, the problem area occurs at the boundary condition between data set 2 and data set 3 , ( 91 ) where there are ΔRPM alterations of short duration in quick succession.
[0109] A means of altering the data set format, without increasing its duration is required and in FIG. 9B , the numbers in the center data set (“n2”) have been rotated 90° clockwise (“CW”), with all the numbers retaining the same position in their grid, relative to each other, but, having moved clockwise relative to the baseline RPM. This schema is also unsatisfactory because it leaves the second data point with only a small sample time, i.e. the first half of a single time frame (t 3 ) to adjust from the baseline to −2 nRPM. As noted previously, this may result in ineffective data transmission.
[0110] FIG. 9C , however, shows the number n 2 data set rotated 90° anti-clockwise (“ACW”) with the result that data in all three data sets now comprises two time periods within each data set. This provides for a longer period of ΔRPM offset, greater downhole sensor sample time and a higher degree of certainty of successful transmission than in the previous examples.
[0111] Irrespective of the number which is to be selected from within any data set, utilizing this method of rotating the numbers within the data sets always yields frame formats where the ΔRPM offset and downhole sample time are at least a half-data set or two time periods in length. Indicators of numerical rotation, e.g. Data Set 1 :ACW, Data Set 2 : CW, Data Set 3 : Normal (not illustrated) may be contained in preamble messages or in acceleration or deceleration ramp profiles as previously discussed.
[0112] The transmission format illustrated in FIG. 9 and prior figures is indicative of the versatility of the invention, but it should be appreciated that these Figures represent a preferred embodiment of the invention and are not intended to limit either its scope or application.
[0113] FIG. 10 is a diagrammatic representation of a preferred embodiment of the surface control apparatus and system of the invention incorporating a feedback mechanism from the distal end of the drilling assembly. A drilling mast ( 1000 ) or derrick which is equipped with a surface rotary motive drive for conveying torque from the surface of the earth ( 1001 ) to a drillstring which penetrates the surface of the earth [Not shown]. The drilling rig is equipped with pumping equipment and means for measuring, at surface, the pressure in the internal diameter of the drilling assembly ( 1002 ). Data is transmitted using pressure pulse telemetry from device(s) located at the distal end of the drilling assembly and pressure fluctuations which are expressly created thereby ( 1003 ) are translated into information at the surface location. The preferred embodiment of the instant apparatus and system contains at a minimum an over-ride mechanism for controlling the rotational velocity of the drillstring, ( 1004 ), in compliance with a pre-determined, but adaptive timing sequence. This comprises an electromechanical or mechanical or electronic or pneumatic linkage to over-ride the traditional rotary motive means controller of the drilling assembly ( 1004 ). The type of linkage is determined by the ease of interface between it and the existing drilling rotary motive means. ( 1001 ). ( 1000 ). For preference and in order to achieve the degree of sophistication of which this invention is capable, the rotary control motive means override mechanism is controlled by a computer. In this way the magnitude and duration of the rotary control communications may be precisely timed and human error removed from any communications sequence. Although, in order to accommodate the effective transfer of relatively large or complex amounts of data it is preferable to have automatic adjustment of the input surface RPM values it is not outside the scope of this invention to accomplish this manually, should this be required. In order to attain the maximum success rate of surface to downhole communications successes a link ( 1006 ) from the pulse telemetered data ( 1003 ) to the surface computer ( 1005 ) may be created. This link allows for processing of information which is transmitted by real-time pulse telemetry and creates an effective real-time feedback loop whereby communications with downhole device(s) may be optimized through having a complete understanding of the downhole environment.
[0114] Yet a further advantage of the system and method is the ability to interchange “master-slave” status between surface and downhole computers. This allows for intelligent development of downhole devices through the use of interactive logic systems. Prior art in this field typically assumes that system over-rides are limited to simple switches which are surface derived and that the downhole device only acts in relation to operator instructions received from the surface of the earth. The instant method allows for adaptive protocols where the downhole device can react to an observed downhole condition and, where a telemetry device is in place, communicate its intentions back to the surface of the wellbore.
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A system, apparatus and method for adaptive communication with a downhole device is disclosed. The instant invention proposes an adaptive system of communicating information from the surface of the earth to a device located downhole; thereby optimizing the drilling process by adaptively fitting the talkdown protocol around the existing drillstring RPM. A further economic benefit is that with this adaptive system the ΔRPM Offset between the optimized drilling condition and the RPM required for data transmission can be monitored and adjusted in real-time, resulting in less disruption to the drilling process. Several embodiments are given.
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(1) TECHNICAL FIELD
This disclosure is related to Magnetic Devices, and more particularly, to methods of integrating Magnetic Devices with semiconductor devices.
(2) BACKGROUND
Magnetoresistive random access memory (MRAM) is one of several new types of random access memory in development that would likely serve as alternatives to the mainstream flash memory design. It maintains a nonvolatile status while retaining the attributes of high speed of reading and writing, high density of capacity, and low consumption of power. The core technology difference between MRAM and other types of nonvolatile random access memory is the method in which it defines and stores digital bits as different magnetic states. Thin magnetic films are stacked in a structure called a magnetic tunnel junction (MTJ) in which the resistance of the MTJ is defined by the relative directions of the magnetic films: parallel or anti-parallel. The variation in electrical current that passes through the two alternating magnetic states of this MTJ structure defines the digital bits (“0” and “1”) for MRAM. The memory bit element can be programmed by a magnetic field created from pulse-current-carrying conductors above and below the junction structure. In a newer design of MRAM, a spin transfer switching technique can be used to manipulate the memory element as well. This new design will allow better packing and shrinkage of individual MTJ devices on the wafer, effectively increasing the overall density of the MRAM memory elements.
MRAM devices are often combined with complementary metal-oxide-semiconductor (CMOS) devices. Process integration involves connection between MRAM and CMOS elements without causing any defect related issues.
U.S. Pat. No. 7,884,433 to Zhong et al and U.S. Patent Application 2011/0089507 to Mao, assigned to the same assignee as the present disclosure, and herein incorporated by reference in their entirety, teach methods of MRAM and CMOS integration. U.S. Pat. No. 7,705,340 to Lin discloses MRAM and CMOS devices. U.S. Pat. Nos. 6,809,951 to Yamaguchi and 6,246,082 to Mitarai et al disclose aluminum bit lines.
SUMMARY
It is the primary objective of the present disclosure to provide an improved method for process integration of MRAM and CMOS devices.
It is another objective of the present disclosure to provide an improved method for fabricating MRAM and CMOS devices that maintains or enhances electrical connectivity and test yield.
It is a further objective to provide an improved method for fabricating MRAM and CMOS devices that maintains or enhances electrical connectivity and test yield without potential shorts during fabrication.
In accordance with the objectives of the present disclosure, a method of fabricating a spin-torque-transfer magnetic random access memory device is achieved. CMOS devices are provided in a substrate having a topmost metal layer wherein the topmost metal layer comprises metal landing pads and metal connecting pads. A plurality of magnetic tunnel junction (MTJ) structures are provided over the CMOS devices and connected to the metal landing pads. The MTJ structures are covered with a dielectric layer that is polished until the MTJ structures are exposed. Openings are etched in the dielectric layer to the metal connecting pads. A seed layer is deposited over the first dielectric layer and on inside walls and bottom of the openings. A copper layer is plated on the seed layer until the copper layer fills the openings. The copper layer is etched back and the seed layer is removed where it is not covered by the copper layer. Thereafter, an aluminum layer is deposited over the dielectric layer, contacting both the copper layer and the MTJ structures and patterned to form a bit line.
Also in accordance with the objectives of the present disclosure, a spin-torque-transfer magnetic random access memory device having excellent electrical connectivity and high test yield is achieved. The device comprises CMOS devices in a substrate having a topmost metal layer wherein the topmost metal layer comprises metal landing pads and metal connecting pads. A plurality of magnetic tunnel junction (MTJ) structures overlie the CMOS devices and are connected to the metal landing pads. An aluminum bit line contacts the MTJ structures and contacts copper connections extending downward through a dielectric layer to the metal connecting pads.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings forming a material part of this description, there is shown:
FIGS. 1-9 are cross-sectional representations of steps in a preferred embodiment of the present disclosure.
DETAILED DESCRIPTION
The present disclosure is a process integration method of fabricating MRAM devices and especially, high-density spin-transfer torque MRAM (STT MRAM) devices. The process integration method of the present disclosure is designed to make the process flow more cost effective and to maintain or even enhance electrical connectivity and test yields without potential shorts due to etching. In this new scheme, one mask layer and the accompanying lithography and etch step and one chemical mechanical polishing (CMP) step can be avoided, thus achieving better manufacturing throughput and cost.
Referring now more particularly to FIGS. 1-9 , the method of the present disclosure will be described in detail. FIG. 1 illustrates a substrate 10 . CMOS devices (not shown) are formed within the substrate. The topmost metal level 12 / 13 of the CMOS device structures is shown, surrounded by dielectric layer 11 . The metal layer 12 may be copper, for example. The metal layer will serve as metal landing pads 12 for MTJ junctions or as connecting pads 13 to the CMOS layers.
Now, the magnetic RAM layers will be formed over the CMOS layers. As shown in FIG. 2 , a dielectric layer 14 is coated over the CMOS metal pads 12 . For example, the dielectric material 14 may include a SiCN cap layer. Intermediate via contacts (VAC) 16 are created to the landing pads 12 , for example, by a single Cu damascene method. Next, a metal separation layer (VAM) 18 is deposited over the second dielectric layer 14 and VAC's 16 by a physical vapor deposition (PVD) or the like. VAM layer 18 may be a single layer or a composite comprised of one or more of Ta, TaN, or other conductive materials.
Referring now to FIG. 3 , the VAM 18 is patterned to form a plurality of VAM pads in the MRAM device region. From a top view (not shown), the VAM pads may be circular, oval, rectangular, or other shapes and preferably have an area size greater than that of the underlying VAC 16 to ensure that the VAC is completely covered by the VAM pad. Thus, from a side view perspective in FIG. 3 , the width of a VAM pad 18 is sufficiently large to cover the underlying VAC 16 . A dielectric layer 19 is coated over the VAM pads and planarized, as shown in FIG. 3 .
Referring to FIG. 4 , an MTJ stack of layers is now formed on the VAM dielectric layer 19 and on VAM pads 18 . Individual layers within the MTJ stack are not shown since the present disclosure encompasses a variety of configurations including bottom spin valve, top spin valve, and dual spin valve structures, and so on. Preferably, the MTJ stack has an uppermost capping layer comprised of a hard mask. In one embodiment, the MTJ stack has a bottom spin valve configuration in which a seed layer, AFM layer, synthetic anti-ferromagnetic (SyAF) pinned layer, tunnel barrier layer, free layer, and a composite capping layer made of a hard mask spacer layer and an uppermost hard mask layer are sequentially formed on the VAM dielectric layer 19 and VAM pads 18 . The hard mask spacer layer may be NiCr or MnPt and the hard mask layer may be Ta, for example, over the free layer. The metal hard mask may be Ta, Ti, TaN, and the like.
The MTJ stack is patterned by a process that includes at least one photolithography step and one etching step to form a plurality of MTJ elements 20 . In an alternative embodiment when two lithography processes are employed to define the MTJ element, a top portion of the MTJ may have a narrower width and smaller area size from a top view than a bottom portion of the MTJ.
A MTJ 20 is formed on each VAM pad 18 and is electrically connected to a CMOS landing pad 12 through a VAM pad 18 and a VAC 16 . Although the exemplary embodiment depicts the MTJ 20 as having a width v less than the width w of the VAM pad 18 , the present disclosure also encompasses an embodiment where v is greater than or equal to w. The shape of MTJ 20 from a top view perspective may be circular, oval, or other shapes used by those skilled in the art.
Now, a MTJ interlayer dielectric (ILD) layer 21 comprised of a dielectric material such as aluminum oxide, silicon oxide, or a low k material known in the art is deposited on the MTJ 20 array and on the VAM dielectric layer 19 by a PVD method or the like. A CMP process is performed to make the MTJ ILD layer 21 coplanar with MTJ's 20 .
In a key feature of the present disclosure, referring to FIG. 5 , a lithographic pattern is formed to provide openings to the CMOS connecting pads 13 . The dielectric layers 21 , 19 , and 14 are etched through to provide openings 25 to the CMOS connecting pads 13 . Now, a barrier layer 26 is deposited over the top planarized MTJ layer and conformally within the openings 25 , as shown in FIG. 6 . The barrier layer 26 is also a seed layer for the subsequent copper deposition. For example, the barrier layer is tantalum, having a thickness of between about 100 and 300 Angstroms, and preferably about 200 Angstroms.
Next, as shown in FIG. 7 , copper plating is performed on the seed layer 26 . Copper 28 is plated to a thickness of between about 0.28 and 0.5 microns, and preferably about 0.3 microns, just enough to ensure that the via for the bit line (MTV) is filled.
An etch back is performed to remove the copper overlying the barrier layer 26 , using layer 26 as an etch stop, and typically using wet chemistry. For example, an etch time of about 132 seconds will remove approximately 1450 Angstroms of copper. Finally, the seed layer 26 is removed where it is not covered by the copper, resulting in FIG. 8 . The seed layer may be removed, for example, by a reactive ion etching (RIE) process.
After Cu etch back and seed removal, the bit line will be formed. In the present disclosure, the bit line is formed of aluminum instead of copper. The aluminum thickness should be about three times the thickness of a copper bit line in order to have the same resistivity performance. For example, the aluminum layer is deposited to a thickness of between about 4000 and 8000 Angstroms. The aluminum layer is etched to form bit line 30 , contacting the MTJ 20 array and the MTV connections 30 , as illustrated in FIG. 9 .
A key feature of the present disclosure is to first use a lithography and etching process to provide an opening to the CMOS devices, next deposit a seed layer, plate copper into the opening, and etch back to form the connection between the CMOS metal layer and the bit line, and finally, to form the bit line by deposition and etching. The bit line contacts the MTJ elements and the connections to the CMOS metal. Etching to form the opening to the CMOS metal layer cannot be guaranteed to proceed completely to the metal layer due to the limited end point signal allowed from a low pattern density of openings. Usually, an over etch is performed to ensure that the opening proceeds all the way to the CMOS metal pads. If a dual damascene process were used to form the CMOS connections and the bit line together, there would be a concern that there might be shorts to the MTJ elements due to the over etching.
However, with the process of the present disclosure, the over etch would not result in shorts because the bit line is not formed yet and etching is performed only over the CMOS metal connecting pads and not in the area of the MTJ elements, which are protected by the lithography mask. Thus, as long as the etch opens to the CMOS metal layer, connectivity is always ensured without a concern for shorts. As a result, test yield can be improved.
Another advantage of the aluminum bit line is that there is no corrosion concern with aluminum as there would be with copper. Also, since there is no copper CMP step, uniformity control should be better.
The present disclosure provides a new conceptual idea of process integration flow for spin torque MRAM products. No dual damascene process is needed to form CMOS connection to the bit line. The advantages of the present disclosure include improved bit line connectivity to CMOS layers through MTV vias and better test yield. The process saves a mask layer step and a CMP process step since the connection and bit line do not have to be planarized.
FIG. 9 illustrates the spin-torque-transfer magnetic random access memory device of the present disclosure, having excellent electrical connectivity and high test yield. The device comprises CMOS devices in a substrate 10 having a topmost metal layer wherein the topmost metal layer comprises metal landing pads 12 and metal connecting pads 13 . A plurality of magnetic tunnel junction (MTJ) structures 20 overlie the CMOS devices and are connected to the metal landing pads 12 , through metal separation pads 18 and intermediate via contacts 16 . An aluminum bit line 30 contacts the MTJ structures 20 and contacts copper connections 28 extending downward through a dielectric layer 21 / 19 / 14 to the metal connecting pads 13 .
Although the preferred embodiment of the present disclosure has been illustrated, and that form has been described in detail, it will be readily understood by those skilled in the art that various modifications may be made therein without departing from the spirit of the disclosure or from the scope of the appended claims.
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CMOS devices are provided in a substrate having a topmost metal layer comprising metal landing pads and metal connecting pads. A plurality of magnetic tunnel junction (MTJ) structures are provided over the CMOS devices and connected to the metal landing pads. The MTJ structures are covered with a dielectric layer that is polished until the MTJ structures are exposed. Openings are etched in the dielectric layer to the metal connecting pads. A seed layer is deposited over the dielectric layer and on inside walls and bottom of the openings. A copper layer is plated on the seed layer until the copper layer fills the openings. The copper layer is etched back and the seed layer is removed. Thereafter, an aluminum layer is deposited over the dielectric layer, contacting both the copper layer and the MTJ structures, and patterned to form a bit line.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus for forming hardcopy images based on print data transmitted from external devices (hereinafter referred to as host device), such as, for example, a personal computer, word processor or like data processing device, or an image reading device.
2. Description of the Related Arts
Conventionally, page printers discharge recording sheets (hereinafter referred to as "sheets") bearing formed images based on printer data transmitted from a host device so as to stack the discharged sheets on a receiving table. Page printers are usually Provided a device for accomplishing a sorting operation wherebY the discharged sheets stacked on the receiving table are removed therefrom and sorted (hereinafter referred to as "sorting operation").
That is, conventional page printers are provided with a sorter device for accommodating distributed sheets in a plurality of bins, a reversing device for inverting the top and bottom sides of the sheet and stacking the inverted sheets on a receiving table, and a slide mechanism for moving the receiving table to shift the position of the accommodated sheets.
When, for example, a five-page document and a ten-page document are continuously printed so that a total of 15 sheets are stacked on the receiving table, the operator can readily sort the sheets of the five-page document and the sheets of the ten-page document.
Methods of controlling the aforesaid devices include a method of control accomplished via command data included with the print data transmitted from a host device, a method of control accomplished via discriminating on the page printer side an interrupt in the input of the print data and like methods. In the previously described conventional image forming apparatus, a mechanical device is attached to perform the sorting operation, thereby increasing both the size and the cost of the apparatus.
SUMMARY OF THE INVENTION
A main object of the present invention is to provide an image forming apparatus compact in size and low in cost.
Another object of the present invention is to provide an image forming apparatus capable of performing a sorting operation without mechanical action.
A further object of the present invention is to provide an image forming apparatus capable of sorting recording sheets by changing the orientation of the image formed on the recording sheet.
A still further object of the present invention is to provide an image forming apparatus connectable to a plurality of external devices and capable of changing the orientation of the images for each external device when the image forming apparatus continually receives image data sequentially from said respective external devices.
These and other objects of the invention are achieved by providing an image forming apparatus for forming images corresponding to image data transmitted from at least one external device onto a recording sheet, said image forming apparatus comprising a data receiving means for receiving image data from an external device, a memory means for converting image data received by the data receiving means into bit configuration and storing said bit data therein, and a control means for controlling to switch image orientation relative to the discharge direction of the recording sheet when the image data is written to the memory means or image data is read from the memory means.
Furthermore, these and other objects of the present invention are achieved by providing an image forming apparatus for forming images corresponding to image data transmitted from external devices onto a recording sheet and connected to a plurality of such external devices, said image forming apparatus comprising a data receiving means for receiving image data from an external device, a memory means for converting image data received by the data receiving means into bit configuration and storing said bit data therein, and a control means for controlling to switch image orientation relative to the discharge direction of the recording sheet when the image data is written to the memory means or the image data is read from the memory means.
These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings which illustrate specific embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following description, like parts are designated by like reference numbers throughout the several drawings.
FIGS. 1a and 1b are a main flow chart showing all operations of a first embodiment of the present invention;
FIG. 2 is a flow chart showing a data process A of the embodiment shown in FIG. 1a;
FIG. 3 is a flow chart showing a buffer check process A shown in FIG. 2;
FIG. 4 is a flow chart showing a data process B of FIG. 1b;
FIG. 5 is a flow chart showing the buffer check B of FIG. 4;
FIG. 6 is a flow chart showing the printing process of FIGS. 2 and 4;
FIGS. 7a and 7b are a flow chart showing the receiving process of the first embodiment of the invention;
FIG. 8 is a block diagram showing the construction of the essential portion of the laser printer related to the present invention;
FIG. 9 is an illustration showing the assignment of the RAM memory area;
FIG. 10 is an exterior view of the printing system of the present invention;
FIG. 11 is an illustration showing the condition of the discharged sheets;
FIG. 12 is a flow chart briefly showing the host operations;
FIG. 13 is a flow chart showing the writing process of another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the invention is described below.
The printing system PS shown in FIG. 10 comprises a laser printer 1 and two personal computers (hosts) 2A and 2B. The laser printer 1 is connected to each host 2A and 2B by means of the cables 3A and 3B, respectively. The hosts 2A and 2B transmit print data DA and DB comprising image data expressing character and graphic information, and control data, respectively.
The laser printer 1 forms images by means of a well known bit map method for writing image data as dot patterns. The papers P bearing the formed image thereon are discharged and stacked one by one on a tray 1a in the main unit.
FIG. 8 is a block diagram showing the essential construction of the laser printer 1.
The laser printer 1 comprises a central processing unit (CPU) 11 for controlling all operations, a read only memory (ROM) 12 for storing process programs and the like, a random access memory (RAM) 13 for storing data (described later) and used as bit map memory, interfaces 14A and 14B used for input from external devices, an interrupt controller 16, a print engine 20 for forming images via an electrophotographic process using a laser light source, a print engine interface 18, and a dip switch interface 17.
The print data DA from the host 2A are input to the interface 14A through a connector 15A and a cable 3A. The print data DB from the host 2B are input to the interface 14B through a connector 15B and a cable 3B.
The interrupt controller 16 inputs the print data DA and DB to the interfaces 14A and 14B, and transmits the interrupt to the CPU 11. In the CPU 11, a receiving process (FIG. 7), described later, is executed as the interrupt process via the aforesaid pause request.
The laser printer 1 of the present embodiment is capable of assigning priority to either one of the interfaces 14A or 14B relative to the other via dip switches not shown in the drawing. That is, one of the interfaces 14A or 14B given precedence receives the print data and when printing is requested, the printing process is temporarily halted even if a printing process is currently being executed for print data of the other interface 14B or 14A, and the printing process of the interface 14A or 14B given priority is executed as a pause process.
Although the interface 14A connected to the host 2A is given priority in the following description, the interface 14B connected to the host 2B may alternatively be given priority.
FIG. 9 is an illustration showing the memory area assignments of the RAM 13.
The RAM 13 is provided a work area E1 for temporary storage of various set values and parameters every time a printing process is executed, backup areas E2A and E2B for storing the print conditions (fonts, margins and the like) assigned by the print data DA and DB, respectively, receiving buffer areas E3A and E3B corresponding to the interfaces 14A and 14B, and a bit map area E4 for writing one-page image data.
FIGS. 1a and 1b are a flow chart showing the operation of the CPU 11.
When the power unit is turned on, each portion is initialized based on the switch state read through the ROM 12 data and the dip switch interface 17 (step 11). At this time, the flags FLAGA, FLAGB, WORKA and WORKB are all set at [0].
The flags FLAGA, and FLAGB respectively indicate the existence of data in the receiving buffer areas E3A and E3B. In the receiving process described later the aforesaid flags FLAGA and FLAGB are set at [1] when data have been stored in the receiving buffer area E3A and E3B. The flags WORKA and WORKB indicate whether or not image writing is currently executing (on-going dot data development) in the bit map area 4. The flag WORKA corresponds to the interface 14A, and the flag WORKB corresponds to the interface 14B.
Next, in step #12, the flag FLAGA is checked to determine the existence of data in receiving buffer area E3A. If the flag FLAGA is set at [0], the flag FLAGB is checked in step #18 to determine the existence of data in the receiving buffer area E3B. If the flag FLAGB is also found to be set at [0], the routine returns to step #12 and the process of steps #12 and #18 are repeated. That is, the entry of the print data DA and DB transmitted from the host 2A or 2B and the storage of said data in the receiving buffer areas E3A or E3B is awaited.
If the flag FLAGA is found to be set at [1] in step #12, the flag WORKB is checked in step #13. When the flag WORKB is found to be set at [1] in step #13, one-page image information corresponding to the print request transmitted from the host 2B is currently being written to the bit map area E4, so that the routine moves to step #18 and the aforesaid writing continues.
If the flag WORKB is found to be set at [0] in step #13, then the routine continues to step #14 where the flag WORKA is checked. If the flag WORKA is set at [1] in step #14, then the data process A corresponding to the priority interface 14A is executed in step #17.
If the flag WORKA is found to be set at [0] in step #14, said flag WORKA is set at [1] in step #15 because data development in bit map area E4 is renewed, or data development of the next page information is started, and the data of the backup area E2A is transferred to the work area E1 in step #16. Next, the data process A is executed in step #17, and the routine returns to step #12 thereafter.
On the other hand, when the flag FLAGB is found to be set at [1] in step #18, the flag WORKA is checked in step #19 to determine whether or not it is set at [0]. If the flag WORKA is found to be set at [0] in step #19, the flag WORKB is checked in step #20 to determine whether or not it is set at [0]. Then, if the flag WORKB is found to be set at [1] in step #20, the data process B corresponding to the interface 14B is executed in step #23.
When the flag WORKB is found to be set at [0] in step #20, it is reset at [1] in step #21, and the data of the backup area E3B is transferred to the work area E1 in step #22. Then, the data process B is executed in step #23, and the routine thereafter returns to step #12.
FIG. 2 is a flow chart for the data process A of step #17 shown in FIG. 1a.
In FIG. 2, first, data of a specified length (for example, 1 byte) are fetched from the receiving buffer area E3A (step #31).
Since an empty area is created in the receiving buffer area E3A when the aforesaid data are fetched, the routine of this process continues and a buffer checking process A is executed in step #32. More specifically, as shown in FIG. 3, input of print data DA to the interface 14A is enabled (step #51), and a ready signal (command data) is output to designate the ready state whereby the laser printer 1 can receive data from the host 2A (step #52). The process in step #51 cancels the input inhibited state occurring when no empty areas remain in the receiving backup area E3A (FULL state). When the interface 14A is a centronics model, the status of the laser printer 1 as being capable of reception in the ready state can be discriminated by the host 2A state without specifically requiring the output of a ready signal.
Referring again to FIG. 2, a check is made in step #33 to determine whether or not the data fetched from the receiving buffer area E3A is command data.
If, in step #33, the fetched data are not found to be command data, i.e., the fetched data are image data, then the image data are written to the bit map area E4 in step #41. At this time, when the image data to be written are character codes, the fonts stored in the work area E1 are selected, and the characters corresponding to these character codes are developed as bit data in the bit map area E4 in accordance with the aforesaid selected fonts.
Then, in step #39, a check is made to determine the existence of data in the receiving buffer area E3A, and if data are present the routine returns to step #31. If data are not present, the flag FLAGA is reset at [0] in step #40.
On the other hand, when the data fetched in step #33 are determined to be command data and said command data are found in step #34 to be page change codes expressing the page break of each page, the printing process is executed in step #35 wherein data are read from the bit map area E4, data are transmitted to the print engine 20 and the like.
If no subsequent data are found in the receiving buffer area E3A in step #36, the flag WORKA is reset at [0] in step #37 to end the printing process, and the data are transferred from the work area E1 to the backup area E2A. When subsequent data are found in the receiving buffer area E3A in step #36, the routine returns to step #31 and the next page printing process is executed.
When the data fetched from the receiving buffer area E3A in step #34 are found to be command data other than the aforesaid page feed codes, the command processes are executed in step #38 in accordance with said command data.
FIG. 4 is a flow chart of the data process B of FIG. 1b.
In the data process B, virtually the same Process as the previously described data process A is executed for the data of the receiving buffer area E3B.
In other words, after the data are fetched from the receiving buffer area E3B, the backup Process B shown in FIG. 5 is executed (steps #61 and #62). Then, a printing process, command process, and writing of the data of bit map area E4 are executed (steps #63, 64, 65, 68 and 71) in accordance with the various data types.
In the data process B, after the printing process has been executed in step #65, the flag WORKB is reset at [0] as the print completion process in step #66 without regard to the existence or absence of data in the receiving buffer area E3B, and finally the data transfer from the work area E1 to the backup area E2B is executed. In other words, the process is temporarily halted every time a onepage segment printing process is completed even when other page segment data remain in the receiving buffer area E3B, then the program returns to the main routine.
Thus, in the laser printer 1, when the print data DA are input from the host 2A during the execution of the printing process for the host 2B, i.e., the writing of the bit map area E4 based on the print data DB, and data output to the print engine 20, the printing process for the executing host 2B is Paused after each page break, or alternatively, the printing process for the host 2A is given priority in execution. Thereafter, when the printing process for the host 2A is completed, and the pause printing process for the host 2B is restarted.
FIG. 6 is a flow chart of the printing processes of FIGS. 2 and 4.
In FIG. 6, the initial check of the flag WORKA is made to determine whether or not the flag is set at [1].
When the flag WORKA is set at [1], printing is executed for the host 2A. In this case, the top address of the bit map area E4 is set by a pointer indicating the address in RAM 13 (step #86).
Then, the pointer address data are read from the bit map area E4 and transmitted to the Print engine 20, whereupon the pointer is incremented. The aforesaid process is repeated until the bottom address of the bit map area E4 is reached (steps #87, 88 and 89). The bit map area E4 is cleared when the reading of the data from all parts of the bit map area E4 has been completed (step #94). The reading of the bit map area E4 is accomplished according to the synchronization signals transmitted from the print engine 20 and in correspondence with the margin values stored in the work area E1. In parallel with the aforesaid process, the photosensitive member in the print engine 20 is exposed to flashing light from a laser light source.
On the other hand, when the flag WORKA is set at [0] and printing is executed for the host 2B, the bottom address of the bit map area E4 is set by the pointer indicating the address in RAM 13 (step #90).
Then, the pointer address data are read from the bit map area E4 and transmitted to the print engine 20, whereupon the pointer is decremented. The aforesaid process is repeated until the top address of the bit map area E4 is reached (steps #91, 92 and 93). The bit map area E4 is cleared when the reading of the data from all parts of the bit map area E4 has been completed (step #94).
That is, when printing for the host 2A, the data are read in the same sequence as the writing sequence from the top address to the bottom address of the bit map area E4. In contrast, the data of the bit map area E4 is read in the reverse to the writing sequence when printing for the host 2B.
Accordingly, as shown in FIG. 11, in the laser printer 1 the orientation of the image G1 comprising the letters "A, B, C, D, E" from the host 2A, and the orientation of the image G2 comprising the numbers "1, 2, 3, 4, 5" from the host 2B are mutually rotated 180° relative to the paper discharge direction (indicated by arrows in the drawing). That is, because the images G1 and G2 are inverted in one orientation and an opposite orientation such that sheets P can be sorted by those corresponding to the host 2A and those corresponding to the host 2B by means of the directional orientations of the images G1 and G2 even when the discharged sheets P are stacked. FIG. 11a shows an example wherein the orientations of the images G1 and G2 coincide with the discharge direction of the sheets P, whereas FIG. 11b shows an example wherein the orientations of the images G1 and G2 are perpendicular to the discharge direction of the sheets P.
FIGS. 7a and 7b are a flow chart of the receiving process.
The main routine of the receiving process is executed whenever required as the pause routine of the main routine of FIG. 1 in correspondence with the input of print data DA and DB to the interfaces 14A and 14B.
When print data is received and a pause process is requested by the interrupt controller 16 in step #101, the CPU 11 checks to determine whether the reception is from the interface 14A or 14B in step #102. If the reception is found to be from the interface 14A in step #102, then the print data DA are stored in the receiving buffer area E3A in step #103, and the flag FLAGA is set to [1] in step #104.
Next, the receiving buffer area E3A is checked in step #105 to determine whether or not it is full. If the buffer area is not full, a ready signal is output to the host 2A in step #108, whereas if the buffer area E3A is full in step #105, input is inhibited to the interface 14A in step #106. A wait signal is output in step #107 to alert the host 2A to the full buffer condition.
On the other hand, if the reception is determined to be from the host 2B in step #102, the print data DB are stored in the receiving buffer area E3B in step #109, and the flag FLAGB is set at [1] in step #110.
When the receiving buffer area E3B is not found to be full in step #111, a ready signal is output to the host 2B, whereas when the buffer area E3B is full in step #111, output to the interface 14B is inhibited in step #112, and a wait signal is output to the host 2B in step #113.
FIG. 12 is a flow chart showing the operations of the hosts 2A and 2B.
After the print data DA and DB are created in step #201, said print data DA and DB having a specified length are output to the laser printer 1 in step #202, i.e., a print request is issued.
Subsequently, the status of the laser printer 1 is read in step #203, and if an error state exists wherein the status indicates a reception abnormality in step #204, then an error process corresponding to the type of error is executed in step #209. If the status does not indicate an error state in step #204, then a wait state obtains in step #205, and the status of the laser printer 1 is read again in step #206, and the ready state is awaited in step #207.
When the status of the laser printer 1 indicates a ready state, the existence of print data DA and DB for transmission is checked in step #208. If data exists, the routine returns to step #202 and the next data are transmitted.
In the previously described embodiment, the directional orientations of the images G1 and G2 on the sheets P discharged in a uniform direction are made mutually dissimilar by switching the sequence of reading the data from the bit map area E4, as illustration in FIG. 6. Alternatively, the directional orientations of the images G1 and G2 may be made mutually dissimilar by switching the sequence of writing data to the bit map area E4.
FIG. 13 is a flow chart of the writing process relating to a second embodiment of the invention. This routine executes a process instead of the step #14 of FIG. 2 or the step #71 of FIG. 4.
First, the WRITE flag setting the writing sequence is checked in step #301. The WRITE flag is set, for example, at [1] at initialization when power is turned on.
When the WRITE flag is set at [1], dot data are developed sequentially from the top address to the bottom address of the bit map area E4, and the image is written (step #302). When the WRITE flag is set at [0], dot data are developed sequentially from the bottom address to the top address of the bit map area E4 (step #305). When one page segment has been completed in the writing via the aforesaid processes, the bit map area E4 is cleared after the data has been transmitted to the print engine 20 in the printing process previously described for FIG. 6. The subsequent page segment is written using an identical sequence.
Thereafter, in step #303, a check is made to determine whether or not the writing of all page segments corresponding to a single print request has been completed. This determination is accomplished, for example, by existence of data in receiving buffer areas E3A or E3B corresponding to the written image. That is, if no data exists, the writing of the print data DA and DB received from the hosts 2A and 2B is completed.
When the writing of all page segments is completed, the set/reset state of the WRITE flag is reversed (step #304). Thus, a second cycle writing sequence is the reverse sequence to the previous cycle writing sequence.
As previously described, when the printing process for the host 2B is pause at each page break so as to give priority to the printing process for the host 2A, the WRITE flag is reversed at the pause time and the printing restart time.
In the aforesaid embodiment, a check is automatically made to determine whether or not the input of print data DA and DB from the host 2A or 2B have paused via the existence of data in the receiving buffer areas E3A or E3B. The image orientation can be switched by the aforesaid process, such that command data generation is not required for a special sorting operation on the host 2a or 2B side.
Although the orientation of the images G1 and G2 corresponding selection of the two hosts 2A and 2B have been switched in the first embodiment described above, said switching may alternatively be accomplished according to the print state set by the command data included in the print data DA and DB. For example, when printing three copies of a five-page document wherein each page of the document is printed on three sheets, the orientation of the images can be switched each time the document page is changed, or the orientation of the images can be changed for each copy when a single of each page is printed.
Furthermore, although the present embodiment has been described in terms of a laser printer 1 connected to two hosts 2A and 2B, the present invention may also be adapted for use with an image forming apparatus connected to a single external device such as, for example, an image reader (external device), and the printing portion of a digital copying machine or facsimile machine.
Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.
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An image forming apparatus for forming images corresponding to image data transmitted from external device by storing the image data in a bit map memory in a bit form and read it out of the bit map memory for printing. When the image data is written to said bit map memory or when the image data is read out of said bit map memory, the image forming apparatus is controlled to switch image orientation recorded on the recording paper with respect to the discharge direction thereof so as to sort recording paper in response to selection of said external device or every series of image data.
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The foregoing abstract is not to be taken as limiting the invention of this application, and in order to understand the full nature and extent of the technical disclosure of this application, reference must be made to the accompanying drawings and the following detailed description.
BACKGROUND OF THE INVENTION
This invention relates to presses for extracting water from a continuous traveling web and particularly to such a press section for extracting water from a newly formed web of paper in a papermaking machine. More particularly it relates to an extended nip press structure and an endless belt utilized in such press structure.
While the present invention relates to dewatering of a continuously running web of any material, it will be described herein with respect to the specific process of dewatering a web of paper. In the papermaking process, the web is formed by depositing the slurry of pulp fibers on a traveling wire. A large portion of the water is normally extracted from the web in the forming area by gravity or suction. The web then passes through what is known as a press section which normally would involve a series of nips of pairs of roll couples in which a substantial amount of the remaining water is squeezed out. The web will then pass on to a drying section which normally is composed of a series of heated drums to drive water off by vaporization. The web then finally passes to such finishing operations as calendering, coating, slitting, winding, et cetera.
The present invention relates specifically to a particular type of press section wherein the pressing operation in each unit is extended in time and thereby results in the extraction of significantly more water than in the heretofore nip of a roll couple. This extended nip pressing is accomplished by wrapping an endless belt about an arc of a rotating drum. The web is sandwiched between the endless belt and the drum and may have a traveling felt on one or both sides thereof for absorbing the water from the web. Additional pressure is provided to the arc of contact area by means of a pressure shoe located on the side of the belt opposite the drum.
The principles and advantages of extended nip pressing have been discussed in U.S. Pat. Nos. 3,798,121 and 3,853,698, both of which are assigned to the assignee of this invention. These principles and advantages, therefore, need not be discussed herein. The present invention, however, is related to an extended nip press of the type disclosed in U.S. Pat. No. 3,853,698 wherein a pressure shoe located on the side of the belt opposite the drum to generate high pressing forces against the web. This is to be distinguished from the type disclosed in aforesaid U.S. Pat. No. 3,798,121 in which the pressure is provided by tension in one or more belts as they pass about the drum.
In the operation of such extended nip press sections having a pressure shoe, a problem has evolved wherein a bulge or bow forms ahead of the nip. The exact phenomenon which causes this bow or bulge is not fully understood. It is clear, however, that center portion of the endless belt in the area of the shoe is compressed, heated by the oil and friction and is otherwise worked differently than the rather wide edges of the belt. The bulge will sometimes be centered on the belt and at other times will be off to one lateral side of the belt. It will sometimes appear on the downstream side of the shoe on the laterally opposite side of the belt relative to a bulge on the upstream side of the belt. Experience thus far shows that the bulge is always confined in lateral directions to the shoe area.
Needless to say, this bulge in the belt is undesirable for many reasons, among which is the fact that it can cause wrinkling or creasing of the web. While the bulge can be eliminated by increasing the tension on the belt, this is not fully satisfactory since it causes increased loading on belts, shafts, bearings and drives. This in turn results in a decrease in the service life of such components and an increase in power consumption and down time.
The complexity of the operating conditions renders a solution to the problem evasive. Presently, pressure shoes having a 10 inch arc of contact and pressures of 600 pounds per square inch are utilized in experimental machines. This means that the belt is subjected to 6,000 pounds of normal force for every inch of width of the belt in the shoe area. Further, it is contemplated that pressures may be increased to 900 pounds per square inch or above and arcs of contact might be increased to as much as 20 inches or more. A 20 inch arc of contact and shoe pressures of 900 psi would result in 18,000 pounds of normal force for each inch of width of the belt in the shoe area.
Further, since the belt is in sliding contact with the shoe and under extremely high pressure, significant heat can be generated due to the sliding friction. The hydraulic fluid in the shoe is maintained at 140 degrees Fahrenheit (46 degrees Centigrade) to maintain the proper viscosity. With the heat caused by the sliding friction and hysteresis losses in the belt added to the heat from the oil, it is believed that belt temperatures may approach 200 degrees Fahrenheit (79 degrees Centigrade).
According to the present invention, an extended nip press section is provided in which circumferentially extending cords are located in the belt only throughout the shoe area. This has permitted elimination of the bulge with substantially less tension in the belt.
Other objects, advantages and features will become more apparent with the disclosure of the principles of the invention and it will be apparent that equivalent structures and methods may be employed within the principles and scope of the invention in connection with the description of the preferred embodiment and the teaching of the principles in the specification, claims and drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of a press section of a papermaking machine;
FIG. 2 is a partial cross-sectional view of the apparatus of FIG. 1 taken substantially along line 2--2 and illustrating the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawing, and in particular FIG. 1, there is illustrated a schematic side elevational view of an extended nip press section 10 of a papermaking machine. The press section 10 includes a press roll 12 rotatable about an axis 14 which extends transversely of the press section. For purposes of this invention, lateral or transverse directions shall be directions which extend parallel to the rotational axis 14 of the press roll 12. Also, longitudical or circumferential directions shall be directions which extend parallel to the direction of motion of the belt or web of paper.
A flexible endless belt 16 is trained about a plurality of pulleys 18 through 22 which are arranged in such a fashion with respect to the press roll 12 that the belt 16 wraps about a portion of the roll 12 to form an arcuate press area 24. One or more of the pulleys 18 through 22 are mounted in a known manner for movement in directions perpendicular to their respective rotational axis to permit installation of the belt 16 and adjustment of the tension in the belt 16.
An arcuate pressure shoe 26 is disposed adjacent the belt 16 on the side thereof opposite the roll 12 and press area 24. A force F is exerted on the pressure shoe by any suitable means to exert a pressure on the belt 18 in the press area. To insure even pressure P across the belt in this area, and minimize sliding friction, hydraulic pressure is supplied through a pipe 28 to a cavity 31. The pressure is regulated by means of a valve 30. The specific mechanical and hydraulic operation of the pressure shoe forms no part of the present invention and, therefore, will not be discussed herein in further detail. Further, although a pressure shoe 26 with a fluid cavity 31 is illustrated, it will be appreciated that a solid pressure shoe with an arcuate surface to mate with the roll 12 could be utilized. For a specific example of a pressure shoe, reference may be had to U.S. Pat. No. 3,853,698.
A felt 32 is trained about the press roll 12 and passes between the press roll 12 and the belt 16. A web of material 34 to be dewatered, is applied to the felt 32 and carried through the press area 24 in the direction of the arrows 36. While only one felt 32 is illustrated, it will be appreciated that a double felt system could be utilized wherein the web of paper or other similar material 34 is sandwiched therebetween.
As best seen in FIG. 2, the pressure shoe 26 is disposed in the transverse center area of the roll 12 and belt 16. The width PW of the pressure shoe is substantially less than the width BW of the belt and, therefore, exerts a pressure only over the center portion of the moving belt. This leaves the laterally outer portions 40,41 free of any normal force or pressure caused by the pressure shoe 26.
As discussed above, during the operation of such an extended nip press, a problem has arisen wherein a bulge or bow appears in the belt 16 on the ingoing side of the nip at various positions across the width PW of the pressure shoe. The bulge or bow can occur in a central location with respect to the shoe or at either lateral side of the shoe. Further, the bulge will sometimes appear at one lateral side of the shoe on the upstream side and at the opposite lateral side of the shoe on the downstream side. Attempts heretofore at eliminating this bulge have generally been directed to increasing the tension in the belt 16. While these attempts have successfully removed the bulge, they also result in undesirably increasing the forces and loads on the belt, bearings and drive.
It has been discovered quite surprisingly that by limiting all reinforcing members which are capable of resisting longitudinal tension to the area of the shoe, the tension required to eliminate the bow or bulge can be reduced quite significantly. Therefore, in accordance with the present invention, a reinforcing structure 38 capable of resisting longitudinal tension is provided in the belt and restricted to the central area BW. This reinforcing structure 38 should include a flexible reinforcing material which is capable of being flexed around the pulleys 18 to 22 and drum 12 without loss of strength. The reinforcing structure also should have enough strength and modulus to absorb the necessary tension in the belt without an unacceptable amount of elongation.
The elastomers used in making the belt should be carefully chosen to provide low hysteresis loss to minimize heat build up. It must be resistant to high temperatures and compatible with whatever hot oil is used in the pressure shoe as well as water and common chemicals used in paper machines. Further, it should have good abrasion resistance and a low coefficient of friction since it will be subjected to sliding friction as it passes over the shoe. Suggested elastomers include acrylonitrile butadienes, ethylene acrylic copolymers, polyurethanes, fluorinated hydrocarbons and epichlorohydrin rubbers.
In the specific embodiment illustrated, the reinforcing structure 38 is comprised of a single strand of rayon cord which was helically wrapped about the mandril at a rate of 15 turns per inch and under a tension of 5 pounds. The rayon had a strength of about 90 pounds per cord resulting in a tensile strength for the belt structure of approximately 1,350 pounds per lineal inch. In some applications it may be desirable to provide a layer of cords of lesser strength extending transversely of the belt for added stability.
The uncured belt structure was then wrapped with a nylon tape and cured in open steam. Subsequent to cool down the outer surface of the belt is ground down to provide the desired thickness in the belt. In prior art, extended nip press sections in which the circumferentially extending reinforcing members extended completely across the belt a tension of 75 to 100 pounds per lineal inch was required to assure that no bulges appeared in the belt. In a structure in accordance with the present invention and in specific in accordance with the embodiment illustrated herein, a tension of only 30 to 50 pounds per lineal inch was required to assure that no bulge or bow developed in the belt.
While a certain representative embodiment and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.
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A press section for extracting water from a continuous traveling web in which the web is sandwiched between a traveling belt and a drum. The belt is wrapped partially about the drum and a pressure shoe exerts pressure on the belt in the wrap area to press the web. The belt includes a reinforcing structure extending circumferentially thereof and disposed locally within the shoe area of the press section.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims all benefits of Japanese Patent Application No. 2004-118856, filed on Apr. 14, 2004, in the Japanese Intellectual Property Office, and Korean Patent Application No. 2004-79209, filed on Oct. 5, 2004, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a memory medium, and, more particularly, to a method of recording and/or reproducing information with respect to a hologram memory medium, in which the information is recorded as interference fringes by using an object beam and a reference beam.
[0004] 2. Related Art
[0005] Recently, a rewritable optical disk of a phase shift type or an optical magnetic type is widely used as an information recording medium. In order to increase the recording density of such an optical disk, reducing the diameter of a beam spot and the distance between adjacent tracks or adjacent bits is required.
[0006] Although the recording density of an optical disk has been increased, the recording density of such an optical disk is physically limited by a diffraction limit of a beam, because data is recorded on a surface. Accordingly, a three-dimensional multi-recording including a depth direction is required to increase the recording density of an optical disk.
[0007] Therefore, a hologram memory medium having a large capacity due to a three-dimensional multi-recording region and a high speed due to a two-dimensional recording/reproducing method has attracted public attention as a next generation of computer file memory. Such a hologram memory medium may be formed by inserting a recording layer, which is formed of a photopolymer, between two sheets of glass. In order to record data on such a hologram memory medium, an object beam corresponding to data to be recorded and a reference beam are irradiated to the hologram memory medium to form interference fringes or interference patterns of the object beam and the reference beam. In order to reproduce data from the hologram memory medium, the reference beam is irradiated to the interference fringes to extract optical data corresponding to the recorded data.
[0008] In addition, hologram memory media having a cube shape and a card shape are provided. For example, Japanese Laid-open Patent No. 2000-67204 discloses a card shaped hologram memory including multiple recording layers on which waveguides are recorded to increase a recording capacity.
[0009] However, when recording/reproducing data on/from such a hologram memory medium, data is recorded on or reproduced from a data recording/reproducing area (or data area) on the hologram memory medium in a horizontal direction along a reference line, also known as a recording route, as shown in FIG. 1 . At the end of the reference line, the recording or the reproducing is stopped to move to an adjacent reference line, and then the recording or the reproducing of data is repeated in the horizontal direction along the adjacent reference line. However, such a method stops the recording or the reproducing of data at the ends of the reference lines. As a result, the operation continuity cannot be secured. Furthermore, the control of a data recording/reproducing optical system becomes complicated.
SUMMARY OF THE INVENTION
[0010] Accordingly, the present invention advantageously provides methods of recording/reproducing information on/from a hologram memory medium in which a recording/reproducing optical system can be conveniently controlled to increase a recording capacity of the hologram memory medium.
[0011] According to an aspect of the present invention, a method of recording information on a card or rectangular shaped hologram memory medium, comprises sequentially recording information on a data recording/reproducing area of the card shaped hologram memory medium along a predetermined route, while maintaining a predetermined distance between stripes of information.
[0012] Accordingly, the information can be continuously recorded on the card shaped hologram memory medium. In addition, the information can be continuously reproduced without operating an optical system, such as an optical pickup, unnecessarily.
[0013] The predetermined route may be formed in a spiral shape that spans the entire data recording/reproducing area of the card shaped hologram memory medium. Since the predetermined route is formed in the spiral shape, the data recording/reproducing area of the card shaped hologram memory medium can be effectively used, and the information may be continuously recorded in the data recording/reproducing area of the card shaped hologram memory medium.
[0014] The information recorded in the data recording/reproducing area of the card shaped hologram memory medium may be sequentially recorded from a central portion to a circumference or periphery of the card shaped hologram memory medium or from the circumference or periphery to the central portion of the card shaped hologram memory medium.
[0015] Accordingly, the data recording/reproducing area of the card shaped hologram memory medium can be effectively used, while continuously recording the information without operating an optical system unnecessarily.
[0016] Alternatively, the predetermined route may be formed in a continuous zig-zag shape that spans the entire data recording/reproducing area of the card shaped hologram memory medium, by having a plurality of reference lines that are parallel to one another and connecting the ends of each reference lines with the start portions of the following reference lines.
[0017] The information recorded on the data recording/reproducing area of the card shaped hologram memory medium may be sequentially recorded from an opened end of a reference line to an opened end of another reference line.
[0018] Accordingly, the data recording/reproducing area of the card shaped hologram memory medium can be effectively used, while continuously recording the information without operating an optical system unnecessarily.
[0019] A recording shape adjacent to a portion of converting a recording direction is a curve. Accordingly, a servo following property of an optical system, such as an optical pickup, may be sufficiently secured even in a portion of converting the recording direction.
[0020] According to an aspect of the present invention, the information may be recorded utilizing a two-dimensional shift multi-recording method. Accordingly, a recording capacity of the card-shaped hologram memory medium may be increased. When the information is recorded utilizing a two-dimensional shift multi-recording method, the distance between the parallel reference lines, which are formed in a spiral shape, is the same as a shift amount of the two-dimensional shift multi-recording. Accordingly, the information may be continuously recorded on the card shaped hologram memory medium, while increasing a recording capacity of the card shaped hologram memory medium, and without operating an optical system unnecessarily.
[0021] The present invention is more specifically described in the following paragraphs by reference to the drawings attached only by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] A better understanding of the present invention will become apparent from the following detailed description of example embodiments and the claims when read in connection with the accompanying drawings, all forming a part of the disclosure of this invention. While the following written and illustrated disclosure focuses on disclosing example embodiments of the invention, it should be clearly understood that the same is by way of illustration and example only and that the invention is not limited thereto. The spirit and scope of the invention are limited only by the terms of the appended claims. The following represents brief descriptions of the drawings, wherein:
[0023] FIG. 1 illustrates a conventional method of recording information on a hologram memory medium useful in gaining a more thorough appreciation of the present invention;
[0024] FIG. 2 illustrates a method of recording/reproducing information on/from a data area of a card shaped hologram memory medium along a recording (reproducing) route in a spiral pattern according to a first embodiment of the present invention;
[0025] FIG. 3 illustrates an adjacent distance according to the first embodiment of the present invention;
[0026] FIG. 4 illustrates example interference fringes recorded in a spiral pattern according to the first embodiment of the present invention;
[0027] FIG. 5 illustrates a method of recording/reproducing information on/from a data area of a card shaped hologram memory medium along a recording (reproducing) route in a continuous zig-zag pattern according to a second embodiment of the present invention;
[0028] FIG. 6 illustrates an adjacent distance according to the second embodiment of the present invention;
[0029] FIG. 7 illustrates example interference fringes according to the second embodiment of the present invention;
[0030] FIG. 8 illustrates an example hologram memory medium according to an embodiment of the present invention;
[0031] FIG. 9 is a block diagram of an example information recording/reproducing apparatus according to an embodiment of the present invention;
[0032] FIG. 10 illustrates an example optical system according to an embodiment of the present invention; and
[0033] FIG. 11 is a flowchart illustrating a method of recording/reproducing information on/from a hologram memory medium according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0034] The present invention is applicable for use with all types of memory or computer-readable media, hologram memory media, data recording/reproducing apparatuses and computer systems implemented methods described according to various embodiments of the present invention. However, for the sake of simplicity, discussions will concentrate mainly on exemplary use of a hologram memory media having a card shape or a rectangular shape, although the scope of the present invention is not limited thereto.
[0035] Attention now is directed to the drawings and particularly to FIGS. 2 through 7 , in which hologram memory media having information recorded by methods of recording information such as video data, audio data, audio/visual (AV) data, computer files or meta information according to various embodiments of the present invention. Specifically, FIG. 2 illustrates a method of recording/reproducing information on/from a data area of a card shaped hologram memory medium along a recording (reproducing) route in a spiral or concentric pattern according to a first embodiment of the present invention. FIGS. 3-4 illustrate an example distance Ws between parallel reference lines established by an interference pattern which is a series of interference fringes that span the entire data area of the hologram memory medium, as shown in FIG. 2 . FIG. 5 illustrates another method of recording/reproducing information on/from a data area of a card shaped hologram memory medium along a recording (reproducing) route in a continuous zig-zag pattern according to a second embodiment of the present invention. FIGS. 6-7 illustrate an example distance Ws between parallel reference lines established by an interference pattern which is a series of interference fringes that span the entire data area of the hologram memory medium, as shown in FIG. 5 . FIG. 8 illustrates a sectional view of a hologram memory medium having servo information i.e., location determination information, recorded thereon which is arranged on a surface facing a surface having a data area.
[0036] In one example embodiment of the present invention, an interference pattern which is a series of interference fringes recorded on the hologram memory medium is formed in a spiral shape, as shown in FIGS. 2 through 4 . Such interference fringes are recorded on the hologram memory medium due to an interference between an object beam and a reference beam during a recording operation. As a result, information can be continuously recorded on or reproduced from the hologram memory medium, starting from a central portion extending to a circumference or periphery of the hologram memory medium, or vice versa, without interruption, i.e., stopping recording or reproducing at an end of a reference line, and restarting at a next, adjacent reference line. In another example embodiment of the present invention, an interference pattern of interference fringes is formed in a continuous zig-zag shape by connecting end portions of reference lines to start portions of following references lines, while arranging the reference lines in parallel to one another, as shown in FIGS. 5 through 7 .
[0037] Referring to FIG. 8 , a hologram memory medium 1 includes a substrate 2 , a hologram recording layer 3 , a total reflection layer 4 , a protective layer 5 , a coat layer (not shown), an adherence layer (not shown), and a substrate 6 having pits 7 in a concave shape or a convex shape. As shown in FIG. 8 , the substrates 2 and 6 serve as bases of the hologram memory medium 1 . The hologram recording layer 3 is formed of a photosensitive material, for example, a photo polymer, a photorefractive crystal or any other material having a high recording/reproducing efficiency and resolution. Such a material should allow for repeated recording and erasing of data without causing a deterioration of the high recording/reproducing efficiency and resolution characteristics. Information of an object beam is recorded as interference fringes on the hologram recording layer 3 by irradiating the object beam and a reference beam to the same location on the hologram memory medium 1 .
[0038] The total reflection layer 4 reflects the object beam and the reference beam that are irradiated to the hologram recording layer 3 to prevent the transmission of the object beam and the reference beam to a surface facing a surface having a data recording/reproducing area. The protective layer 5 physically protects servo information, in other words, the pits 7 , in a concave shape or a convex shape formed on the substrate 6 from the outside.
[0039] The pits 7 include servo information of an optical system, such as an optical pickup, which records or reproduces information. Accordingly, the servo information can be optically read from the substrate 6 of the hologram memory medium 1 so as to properly control the location of the optical system, i.e., the irradiation location of the object beam and the reference beam from the optical system.
[0040] The pit row shape is symmetrical with the recording shape of the interference fringes (interference stripes), which are recorded on the hologram memory medium. For example, when the interference fringes are formed in a spiral shape, the pit row is formed in a spiral shape symmetrical with the spiral shape of the interference stripes.
[0041] Referring to FIGS. 3 and 6 , the distance W S between the parallel reference lines is applied to a two-dimensional multi-recording method. Therefore, the distance W s may be the same as a shift amount of the two-dimensional multi-recording method. Accordingly, the distance between the pit rows is the same of the distance WS between the reference lines. The examples of the interference stripes, which are recorded by the two-dimensional shift multi-recording method, are shown in FIGS. 4 and 7 .
[0042] In addition, recording information corresponding to table of content (TOC) data of a compact disk (CD) or a DVD is recorded in a predetermined location of the data recording/reproducing area. Such recording information recorded in the data recording/reproducing area includes location information, in other words, address data, recorded in each data row as well as actual recording information. Accordingly, an access to a predetermined data row can be performed by using the information corresponding to the TOC data and the address data of each data row.
[0043] Turning now to FIG. 9 , an information recording/reproducing apparatus for recording/reproducing information on/from a hologram memory medium according to an embodiment of the present invention is illustrated. As shown in FIG. 9 , the information recording/reproducing apparatus includes a hologram memory medium transferring motor 10 , an optical pickup 11 , a feed motor 12 , a signal process integrated circuit (IC) 13 , a central processing unit (CPU) 14 , and a driver integrated circuit (IC) 15 .
[0044] The hologram memory medium transferring motor 10 transfers a hologram memory medium 1 in a different direction from a reference line to the same distance as the shift amount of a shift multi-recording, at the end portion of the reference line. In addition, the transfer of the hologram memory medium transferring motor 10 is controlled by the output of the driver IC 15 .
[0045] The optical pickup 11 includes optical elements such as a laser light source, for example, a semiconductor laser, a collimator lens, an object lens, which is driven by a focus actuator or a tracking actuator, and a polarizing beam splitter, and a light receiving device.
[0046] The feed motor 12 moves the optical pickup 11 to a predetermined location along the hologram memory medium 1 . More specifically, in a search operation, the feed motor 12 controls the location of the optical pickup 11 by using a driving voltage supplied from the driver IC 15 . The driving voltage may be obtained, for example, based on the address data recorded on the hologram memory medium 1 .
[0047] The signal process IC 13 generates a reproducing signal based on a return light quantity from the hologram memory medium 1 that is received by the light receiving device (not shown) in the optical pickup 11 , while generating a focus error (FE) signal obtained by detecting a focus error of a radiation laser from the optical pickup 11 by an astigmatism method based on the return light quantity obtained by the light receiving device (not shown) in the optical pickup 11 . Furthermore, the signal process IC 13 generates a track error (TE) signal obtained by detecting an error in the radiation laser from the optical pickup 11 in a reference line direction by a push-pull method. In addition, the signal process IC 13 generates a focus driving (FODRV) signal and a tracking driving (TRDRV) signal based on the FE and TE signals.
[0048] The CPU 14 controls the information recording/reproducing apparatus based on a control program stored in an internal memory such as a read only memory (ROM). According to an embodiment of the present invention, the CPU 14 controls various servo operations when recording information on the hologram memory medium 1 . More specifically, the CPU 14 calculates a driving voltage of the feed motor 12 that is required to move the optical pickup 11 based on the present address data and the address data of a target location in a search operation, and supplies the driving voltage of the feed motor 12 to the driver IC 15 through the signal process IC 13 .
[0049] The driver IC 15 inputs the focus driving (FODRV) signal or the tracking driving (TRDRV) signal that are generated in the signal process IC 13 , and amplifies the input focus driving (FODRV) signal or tracking driving (TRDRV) signal to a predetermined size. Thereafter, the driver IC 15 supplies the amplified signal to a focus actuator or a tracking actuator.
[0050] Referring to FIG. 10 , an example optical system, such as an optical pickup 11 , shown in FIG. 9 , for use in an information recording/reproducing apparatus according to an embodiment of the present invention is illustrated. As shown in FIG. 10 , such an optical system includes a data recording/reproducing optical system 20 and a location determination controlling optical system 30 . The data recording/reproducing optical system 20 records information in the data recording/reproducing area of the hologram memory medium 1 and reproduces information from the data recording/reproducing area of the hologram memory medium 1 . The location determination controlling optical system 30 performs the location determination control of the object beam and the reference beam irradiated from the data recording/reproducing system 20 based on the servo information, when recording/reproducing information on/from the hologram memory medium 1 . In addition, the data recording/reproducing optical system 20 and the location determination controlling optical system 30 are integrally formed. In such a situation, the location determination controlling optical system 30 transfers inconnection with the transfer of the data recording/reproducing optical system 20 . However, the data recording/reproducing optical system 20 and the location determination controlling optical system 30 can also be physically separated. In such a situation, a control signal may be fed back from the location determination controlling optical system 30 to the data recording/reproducing optical system 20 so as to determine the location of the optical system.
[0051] Turning now to FIG. 11 , a method of recording information on a hologram memory medium utilizing an information recording/reproducing apparatus according to an embodiment of the present invention will now be described as follows.
[0052] When a hologram memory medium 1 is mounted in an information recording/reproducing apparatus in S 101 , a CPU 14 calculates a driving voltage of a feed motor 12 for transferring an optical pickup 11 based on address data from a location determination controlling optical system 30 in order to transfer the optical pickup 11 to a home position having recording information in the hologram memory medium 1 by supplying the driving voltage of the feed motor 12 to a driver IC 15 through a signal process IC 13 , in S 102 .
[0053] Thereafter, the CPU 14 reads information corresponding to table of content (TOC) data, which is recorded around the home position, from a reproducing signal from the location determination controlling optical system 30 in order to determine whether the information is preliminarily recorded on the hologram memory medium 1 , in S 103 . In the case where the information is not recorded on the hologram memory medium 1 , the data recording/reproducing optical system 20 is transferred to a predetermined recording start location, in S 104 .
[0054] In the case where the information is recorded on the hologram memory medium 1 , the data recording/reproducing optical system 20 is transferred to an address, which is obtained by shifting from the address of the last information by the amount corresponding to the shift amount of a shift multi-recording, in S 105 . When the recording/reproducing optical system 20 is transferred to a predetermined location, the data recording/reproducing optical system 20 radiates an object beam and a reference beam to the data recording/reproducing area of the hologram memory medium 1 to record predetermined information as interference stripes, in S 106 . Thereafter, the data recording/reproducing optical system 20 records information, while shifting by a predetermined amount based on location determination information, which is obtained from the location determination controlling optical system 30 .
[0055] As described from the foregoing, the present invention advantageously provides methods of recording/reproducing information on/from a card type hologram memory medium, in which a data recording/reproducing area of the hologram memory medium can be effectively used, and information can be continuously recorded and reproduced. As a result, the operation continuity can be secured, and the control of a data recording/reproducing optical system can be simplified. In addition, such recording/reproducing methods can advantageously utilize two-dimensional shift multi-recording and reproducing techniques.
[0056] While there have been illustrated and described what are considered to be example embodiments of the present invention, it will be understood by those skilled in the art and as technology develops that various changes and modification may be made, and equivalents may be substituted for elements thereof without departing from the spirit and scope of the present invention. Many modifications may be made to adapt the teachings of the present invention to a particular situation without departing from the scope thereof. For example, the hologram memory medium can be formed in different sizes and shapes, such as square, cube, spherical and elliptical shape, as long as information can be continuously recorded on or reproduced from the hologram memory medium without interruption. In addition, the hologram memory medium can be a recordable medium formed of a photo-polymer, a multi-waveguide type medium or a rewritable medium formed of photorefractive crystals, such as LiNbO 3 (lithium niobate). Similarly, the CPU can be implemented as a chipset having firmware, or alternatively, a general or special purposed computer programmed to perform the methods as described with reference to FIGS. 2-7 . Moreover, such a hologram memory medium can also have a wide range of applications, including multimedia computing, video-on demand, high-definition televisions, portable computing and consumer video. Accordingly, it is intended, therefore, that the present invention not be limited to the various example embodiments disclosed, but that the present invention includes all embodiments falling within the scope of the appended claims.
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A method of recording/reproducing information on/from a card-shaped hologram memory medium is provided in which an information recording/reproducing optical system can be conveniently controlled to increase a recording capacity of the card-shaped hologram memory medium. In the method, pieces of information are sequentially recorded in a data recording/reproducing area of the card shaped hologram memory medium along a predetermined route, while maintaining a predetermined distance between pieces of information.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a shared vehicle port and a method and an apparatus for controlling the shared vehicle port in a shared vehicle operating system.
This application is based on Japanese Patent Application Nos. Hei 10-255782 and Hei 10-255781, the contents of which are incorporated herein by reference.
2. Background Art
To alleviate traffic jams and to utilize energy effectively, the present applicant proposes a shared vehicle operating system (in Japanese Patent Applications, First Publication Nos. Hei 8-110997, Hei 8-111908, and Hei 8-147555).
FIG. 6 is a diagram for explaining the introduction of the shared vehicle operating system.
As shown in this figure, the shared vehicle operating system includes shared vehicle ports 100 distributed over the area. Users can park the shared vehicles 101 in the shared vehicle ports 100 .
The user rents the shared vehicle 101 from the nearest shared vehicle port 100 , goes to his destination by the shared vehicle 101 , and returns the shared vehicle 101 to the shared vehicle port 100 nearest the destination. The returned shared vehicle 101 is parked in the shared vehicle port 100 , and will be used by another user who goes to another destination.
This shared vehicle operating system provides shared vehicles 101 to a number of users, thereby eliminating traffic jams and utilizing energy effectively.
Next, the shared vehicle port will be explained below.
FIG. 7 is a diagram for explaining an example of a conventional shared vehicle port.
In this figure, reference numeral 102 denotes a gateway, and reference numeral 103 denotes a parking area for the shared vehicles. The shared vehicles goes in and out of the shared vehicle ports 100 through the gateway 102 .
The above shared vehicle port, however, cannot simultaneously allow the entrance and the exit of the shared vehicles to and from the shared vehicle port 100 . Therefore, the shared vehicles cannot move in and out smoothly.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a shared vehicle port and a method for controlling the same, which allow the shared vehicles to move in and out smoothly.
The shared vehicle port of the present invention for automatically parking and delivering a shared vehicle used by a plurality of users, comprises: an automatic driving area having a passenger loading area and a passenger unloading area separated from each other and being connected to a vehicle passage via the passenger loading area and the passenger unloading area; and a user waiting area adjacent to the vehicle passage, the passenger loading area, and the passenger unloading area.
According to the invention, shared vehicles arrive at the passenger unloading area while they separately start from the passenger loading area. Thus, the entrance and exit of the shared vehicles can be accomplished smoothly.
In another aspect of the invention, the user waiting area includes a port terminal for performing operations to rent and return the shared vehicle.
To rent the shared vehicle, the user performs the rental operation to rent the vehicle through the port terminal in the user waiting area adjacent the passenger loading area, and immediately gets into the vehicle in the passenger loading area. To return the shared vehicle, the user exits the vehicle in the passenger unloading area, and immediately performs the returning operation to return the vehicle through the port terminal in the user waiting area. Thus, the rental operation is performed just before the user gets into the vehicle, the returning operation is performed just after the user exits the vehicle. This simplifies the management of the users who rent and return the vehicles.
In another aspect of the invention, an automatic entrance door, which is locked when no shared vehicle is parked in the passenger loading area, is provided between the passenger loading area and the user waiting area, and an automatic exit door, which is locked when no shared vehicle is parked in the passenger unloading area, is provided between the passenger unloading area and the user waiting area.
The automatic entrance door is opened only when a shared vehicle stops in the passenger loading area, while the automatic exit door is opened only when a shared vehicle stops in the passenger unloading area. This invention completely separates the users and the automatically driven shared vehicles.
In another aspect of the invention, the method for controlling a shared vehicle port for automatically parking and delivering a shared vehicle used by a plurality of users, comprises the steps of: performing a rental procedure for renting the shared vehicle according to an operation from a user waiting area adjacent to a vehicle passage, a passenger loading area, and a passenger unloading area; sending an instruction to automatically deliver the shared vehicle after completion of the rental procedure; moving the shared vehicle to the passenger loading area adjacent to the vehicle passage according to the instruction to deliver the shared vehicle; performing a returning procedure for returning the shared vehicle according to an operation from the user waiting area; sending an instruction to automatically park the shared vehicle after the return of said shared vehicle has been completed; and moving the shared vehicle, which is parked in the passenger unloading area adjacent to the vehicle passage, to a shared vehicle parking area.
When the rental procedure is performed, the shared vehicle is moved to the passenger loading area according to the instruction to automatically deliver the vehicle. When the returning procedure is performed, the shared vehicle is moved to the shared car parking area according to the instruction to automatically park the vehicle. These processes are performed separately in the passenger loading area and the passenger unloading area. Therefore, the entrance and exit of the shared vehicles are performed smoothly.
In another aspect of the invention, the method further comprises the steps of: unlocking an automatic entrance door between the passenger loading area and the user waiting area when the shared vehicle stops in the passenger loading area; and unlocking an automatic exit door between the passenger unloading area and the user waiting area when the shared vehicle stops in the passenger unloading area.
The automatic entrance door is opened only when a shared vehicle stops in the passenger loading area, while the automatic exit door is opened only when a shared vehicle stops in the passenger unloading area. This invention completely separates the users and the automatically driven shared vehicles.
In another aspect of the invention, the method further comprises the steps of: opening a passenger loading area gate between the passenger loading area and the vehicle passage when a user gets into the shared vehicle in the passenger loading area; closing the passenger loading area gate when the shared vehicle exits to the vehicle passage; opening a passenger unloading area gate between the passenger unloading area and the vehicle passage when the shared vehicle reaches the shared vehicle port; and closing the passenger unloading area gate when the shared vehicle stops at the passenger unloading area.
The passenger loading area gate is opened only when the shared vehicle goes out, while the passenger unloading area gate is opened only when the shared vehicle goes in. Therefore, a vehicle other than a shared vehicle cannot enter the passenger loading area and the passenger unloading area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram for explaining the structure of the shared vehicle port of the present invention.
FIG. 2 is a diagram for explaining the modification of the shared vehicle port of the present invention.
FIG. 3 is a block diagram showing the electrical connections between the parts of the shared vehicle port of the present invention.
FIG. 4 is a flow chart showing the process to allow a user to get into the vehicle in the shared vehicle port of the present invention.
FIG. 5 is a flow chart showing the process to allow a user to exit the vehicle in the shared vehicle port of the present invention.
FIG. 6 is a diagram showing an example of the introduction of the shared vehicle operating system.
FIG. 7 is a diagram showing an example of the conventional shared vehicle operating system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be explained with reference to the figures.
FIG. 1 is a diagram for explaining the structure of the shared vehicle port in the embodiment according to the present invention.
The shared vehicles 1 are, for example, electric vehicles. Each shared vehicle 1 has a computer, which includes a CPU (central processing unit) and peripheral devices, a navigation system, and a radio transceiver 24 (which includes an antenna). The shared vehicles are automatically driven according to instructions.
The computer automatically drives the shared vehicle (controls the drive motor, brakes, and steering) along guide lines 11 according to instructions from a port terminal 19 , and, when automatic driving is not performed (i.e., when manual driving is performed), also controls the running shared vehicle (controls driving the drive motor, etc.) according to a user operation. The navigation system detects the position of the vehicle, displays a map, and performs route guidance.
The shared vehicle port 2 is adjacent to a vehicle passage 3 . The vehicle passage 3 is a road (for example, an ordinary road) through which the vehicles (the shared vehicles or ordinary vehicles) are driven by the users.
The shared vehicle port 2 is comprised by an automatic driving area 4 and a user waiting area 5 . In the automatic driving area 4 , the shared vehicle 1 is parked and delivered by an automatic operation. In the user waiting area 5 , a user performs operations to rent and return the shared vehicle. The user waiting area 5 also serves as a waiting room.
The automatic driving area 4 has a U-shape surrounding the user waiting area 5 . At the opening of the U-shape of the automatic driving area 4 , the user waiting area 5 is adjacent to the vehicle passage 3 .
The automatic driving area 4 is comprised by a fully automatic area 6 , a passenger loading area 7 , and a passenger unloading area 8 . The automatic driving area 4 is connected via the passenger loading area 7 and the passenger unloading area 8 to the vehicle passage 3 . The user gets in the shared vehicle 1 in the passenger loading area 7 , while the user leaves the shared vehicle 1 in the passenger unloading area 8 .
In the fully automatic area 6 , a shared vehicle parking area 9 is provided opposite to the vehicle passage 3 . In the shared vehicle parking area 9 , a number of the shared vehicles 1 (five vehicles in FIG. 1) can be parked. The shared vehicle parking area 9 also serves as a charging port, and an automatic charger 10 is provided therein.
Between the passenger loading area 7 and the passenger unloading area 8 , the guide line 11 for guiding the shared vehicle 1 is laid. Between the passenger loading area 7 and the parking spaces in the shared vehicle parking area 9 , the guide lines 11 are branched from the main guide line 11 connecting the passenger loading area 7 and passenger unloading area 8 .
The guide lines 11 are guide cables embedded in the automatic driving area 4 , and generate magnetic signals from an applied alternating current. A magnetic sensor loaded on the shared vehicle 1 detects the alternating current. Based on this detection, it is determined whether the shared vehicle 1 is positioned on the guide lines 11 , and the shared vehicle 1 is automatically driven along the guide lines 11 . The method for guiding the shared vehicle 1 is not limited to this, and may use an optical sensor for detecting white lines drawn on the ground or other known processes.
According to the layout of the shared vehicle port in the embodiment, to park a large number of cars, parking spaces for the shared vehicles 1 can be added as shown in FIG. 2 . Thus, even when a large number of cars are parked, the number of the guide lines 11 can be reduced, and the length of the guide lines 11 remains short. As the number of the parked cars increases, the entire added area can be assigned for the shared vehicle parking area 9 , thus effectively utilizing the area.
In FIG. 1, magnetic nails 12 are permanent magnets embedded in the automatic driving area 4 in the shared vehicle port 2 . A magnetic nail sensor (not shown) loaded on the shared vehicle 1 detects that the shared vehicle 1 is passing over the magnetic nail 12 . The guide lines 11 enable the detection of disalignment of the shared vehicle 1 in the right-left directions, while the magnetic nails 12 enable the detection of disalignment of the shared vehicle 1 in the front-rear direction. The magnetic nails 12 are embedded at the stop points (in the passenger loading area 7 and the passenger unloading area 8 ) to confirm the arrival of the shared vehicle 1 at the stop point, and on the curves and at the junctions of the guide lines 11 to detect these curves and junctions. In addition to these points, the magnetic nails 12 may be embedded on the guide lines 11 at intervals of, for example, 30 cm.
In the passenger loading area 7 near the vehicle passage 3 , a passenger loading area chain (gate) 13 is provided. Also, in the passenger unloading area 8 near the vehicle passage 3 , a passenger unloading area chain (gate) 14 is provided. The passenger loading area chain 13 and the passenger unloading area chain 14 can be moved vertically to forbid or permit the shared vehicle 1 to pass between the vehicle passage 3 and the automatic driving area 4 .
At four corners of the passenger loading area 7 and at four corners of the passenger unloading area 8 , phototubes 15 are provided to detect objects (such as people, obstacles, shared vehicles, or ordinary cars).
In the user waiting area 5 , an auto matic entrance door 16 , an automatic exit door 17 , and a manual door 18 are provided. Through the automatic entrance door 16 , the user exits from the user waiting area 5 and gets into the shared vehicle 1 stopped in the passenger loading area 7 . Through the automatic exit door 17 , the user exits the shared vehicle 1 stopped in the passenger unloading area 8 and enters the user waiting area 5 . The manual door 18 allows the user to go in and out of the user waiting area 5 from and to the outside area (the vehicle passage 3 ).
The user waiting area 5 includes a port terminal 19 for performing the operations to rent and return the shared vehicle 1 . The port terminal 19 is a computer which includes a CPU and peripheral devices, and has a read/write unit 20 (hereinafter referred to as “RWU”, see FIG. 3) and a communication interface (I/F) 21 (see FIG. 3 ).
The RWU 20 writes and reads data to and from an IC card for administration of the user. In this embodiment, the user has only to hold the IC card over the RWU 20 , which then performs the read/write operation to and from the IC card.
The communication I/F 21 is connected to, for example, a cable communication network (such as the Ethernet). The cable communication network is connected to radio communication antennas 22 . The radio communication antennas 22 are positioned along the vehicle passage 3 at predetermined intervals (for example, at intervals of 100 meters). The radio communication antennas 22 are provided also in the user waiting area 5 . The port terminal 19 sends and receives signals to and from the shared vehicles 1 via the communication I/F 21 , the radio communication antennas 22 , and the cable communication network.
FIG. 3 is a block diagram showing an example of the electrical connections between the parts in FIG. 1 .
In FIG. 3, the same reference numbers are employed to designate like parts in FIG. 1 and a detailed description is omitted.
A CPU 23 is included in the port terminal 19 , and controls the parts of the shared vehicle port 2 according to a flow chart described later.
The CPU 23 can lock the automatic entrance door 16 and the automatic exit door 17 . When the doors are locked, the user cannot open the automatic entrance door 16 and the automatic exit door 17 .
Further, the CPU 23 controls the vertical movement of the passenger loading are a chain 13 and the passenger unloading area chain 14 .
Furthermore, the CPU 23 monitors the passenger loading area 7 and the passenger unloading area 8 through the phototubes 15 . When an object other than the shared vehicle 1 (for example, people, obstacles, or an ordinary car) is found, the process for automatically parking and delivering the shared vehicle 1 in the automatic driving area 4 is stopped.
The process to allow the user to get into the shared vehicle using the above described structure will be explained.
FIG. 4 is a flow chart showing an example of the process to allow the user to get into the shared vehicle in the shared vehicle port.
The CPU 23 in the port terminal 19 locks the automatic entrance door 16 (step SI).
When the user holds the IC card over the RWU 20 of the port terminal 19 , the CPU 23 in the port terminal 19 detects the IC card in step S 2 . On detecting the IC card, the CPU 23 in the port terminal 19 performs a rental procedure for renting the shared vehicle 1 . For example, verification of the ID number of the IC card, selection of the available shared vehicle 1 (based on battery check or the like), etc., are performed.
When the rental procedure is completed, the CPU 23 in the port terminal 19 instructs the delivery of the shared vehicle 1 using the radio communication in step S 3 .
On receiving the instruction, the CPU of one of the shared vehicles 1 parked in the shared vehicle parking area 9 sets a shift lever to a drive range to start the shared vehicle 1 in step S 4 . The CPU of the shared vehicle 1 drives the shared vehicle 1 along the guide line 11 to the passenger loading area 7 , and stops the shared vehicle 1 when detecting the magnetic nail 12 in the passenger loading area 7 . Then, the CPU of the shared vehicle 1 sets the shift lever to a parking range, and transmits a signal indicating the stopping of the shared vehicle 1 using the radio communication.
On receiving the stopping signal of the shared vehicle, the CPU 23 in the port terminal 19 unlocks the automatic entrance door 16 in step S 5 .
When the user approaches the shared vehicle 1 through the automatic entrance door 16 and holds the IC over the door of the shared vehicle 1 , the CPU of the shared vehicle 1 opens the door of the shared vehicle 1 in step S 6 . When the user gets into the shared vehicle 1 and inserts the IC card into a driver's panel, the CPU of the shared vehicle 1 transmits the completion of getting into the car.
On receiving the completion of getting on the car, the CPU 23 in the port terminal lowers (opens) the passenger loading area chain 13 in step S 7 . Then, the user drives the shared vehicle 1 to exit to the vehicle passage 3 .
When the shared vehicle 1 goes out to the vehicle passage 3 , the CPU 23 in the port terminal 19 detects the exit of the shared vehicle 1 by the phototubes 15 in step S 8 .
When the exit of the shared vehicle 1 is detected, the CPU 23 in the port terminal 19 raises (closes) the passenger loading area chain 13 in step S 9 .
Thus, the process to allow the user to get into the car in the shared vehicle port is completed.
The process to allow the user to exit the shared vehicle in the shared vehicle port will be explained.
FIG. 5 is a flow chart showing one example of the process to allow the user to exit the car in the shared vehicle port.
The CPU 23 in the port terminal 19 normally locks the automatic exit door 17 (step S 10 ).
In step S 11 , the CPU of the shared vehicle 1 transmits its car position as detected by the navigation system by the radio transceiver 24 . The transmitted car position is received by the radio communication antenna 22 , and sent via the communication I/F 21 to the CPU 23 in the port terminal 19 . The CPU 23 in the port terminal 19 compares a predetermined position in the shared vehicle port 2 with the received position of the shared vehicle 1 , and then determines whether the shared vehicle 1 has reached the position.
In another example, because the communication range between the radio communication antenna 22 and the radio transceiver 24 (on the shared vehicle 1 ) is comparatively short, the arrival of the shared vehicle 1 may be determined by detecting that the shared vehicle 1 enters the communication range around the radio communication antenna near the port terminal 19 .
When the shared vehicle 1 reaches the connection point between the vehicle passage 3 and the passenger unloading area 8 , the CPU 23 in the port terminal 19 detects the arrival of the shared vehicle 1 by the phototubes 15 in step S 12 .
When the arrival of the shared vehicle 1 is detected, the CPU 23 in the port terminal 19 lowers (opens) the passenger unloading area chain 14 in step S 13 . Then, the user drives the shared vehicle 1 into the passenger unloading area 8 .
When the shared vehicle 1 enters and stops in the passenger unloading area 8 , the CPU of the shared vehicle 1 transmits a signal indicating the stopping of the shared vehicle 1 using the radio communication in step S 14 . Then, the CPU of the shared vehicle 1 plays the necessary messages such as “Do not leave things behind” from speakers of the navigation system.
On receiving the signal indicating the stopping of the shared vehicle 1 , the CPU 23 in the port terminal raises the passenger unloading area chain 14 in step S 15 .
Further, on receiving the stopping of the shared vehicle 1 , the CPU 23 in the port terminal 19 unlocks the automatic exit door 17 in step S 16 .
The user in the shared vehicle 1 sets the shift lever to the parking range, pulls out the IC card from the driver's panel, exits the shared vehicle 1 , and closes the door of the shared vehicle 1 . Then, the user enters the user waiting area 5 through the automatic exit door 17 , and holds the IC card over the RWU 20 of the port terminal 19 .
When the user holds the IC card over the RWU 20 of the port terminal, the CPU 23 of the port terminal 19 detects the IC card in step S 17 . When the IC card is detected, the CPU 23 of the port terminal 19 performs a returning procedure for returning the shared vehicle 1 . In this returning procedure, verification of the ID number of the IC card, calculation of the charge by time (for use of the shared vehicle 1 ), etc., are performed.
When the returning procedure is completed, the CPU 23 in the port terminal 19 instructs the automatic parking of the shared vehicle 1 by the radio communication in step S 18 .
On receiving the instruction, the CPU of the shared vehicle 1 stopped in the passenger unloading area 8 sets the shift lever to the drive range, and starts the shared vehicle 1 in step S 19 . The CPU of the shared vehicle 1 drives the shared vehicle 1 along the guide lines 11 to the shared vehicle parking area 9 , and stops the shared vehicle 1 when detecting the magnetic nail 12 in the shared vehicle parking area 9 . Then, the CPU of the shared vehicle 1 sets the shift lever to the parking range.
When the amount of electric energy stored in the battery is not enough, the CPU of the shared vehicle 1 moves the shared vehicle 1 to the charging port (which is at the end of the shared vehicle parking area 9 ).
Thus, the process to allow the user to exit the shared vehicle 1 is completed.
This invention may be embodied in other forms or carried out in other ways without departing from the spirit thereof. The present embodiments are therefore to be considered in all respects illustrative and not limiting, the scope of the invention being indicated by the appended claims, and all modifications falling within the meaning and range of equivalency are intended to be embraced therein.
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The present invention relates to the shared vehicle port for automatically parking and delivering a shared vehicle used by a plurality of users, comprising: an automatic driving area having a passenger loading area and a passenger unloading area separated from each other and being connected to a vehicle passage via the passenger loading area and the passenger unloading area; and a user waiting area adjacent to the vehicle passage, the passenger loading area, and the passenger unloading area.
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This continuation application claims priority to U.S. patent application Ser. No. 09/785,571 filed Feb. 16, 2001, which is now a U.S. Pat. No. 6,522,806.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to a novel optical fiber having a diffuser portion and continuous unitarily-constructed outer sleeve, which is adapted for the transmission of light to a treatment locale. More particularly, the invention relates to a medical instrument with an optical fiber including a diffuser portion at a distal end wherein an alignment sleeve for the optical fiber extends uninterruptedly in a single piece from a connector for a laser light source to at least the distal end of the core of the optical fiber.
Currently, surgeons frequently employ medical instruments which incorporate laser technology in the treatment of benign prostatic hyperplasia, or as commonly referred to as BPH. BPH is a condition of an enlarged prostate gland, in which the gland having BPH typically increases in size to between about two to four times from normal. The lasers which are employed by the surgeons to treat this condition must have durable optical fibers that distribute light radially in a predictable and controlled manner, and must also be capable of bending without breaking, whereby small-sized or slender optical fibers offer an additional advantage to the surgeon.
An optical fiber which is adapted to be employed for this purpose typically contains a glass core surrounded by cladding, a buffer layer, and an outer alignment sleeve. The cladding protects the inherently weaker glass core by imparting a mechanical support to the core. The cladding also ordinarily possesses an index of refraction which is lower than that of the core in order to block light transmitted through the optical fiber from emerging radially from the core. Although optical fibers which are utilizable for such surgical procedures and treatments are widely known and successfully employed, the present invention is designed to provide further significant improvements and advantages over the state-of-the art.
2. Discussion of the Prior Art
An optical fiber with a diffuser portion for diffusing light emitted at an end thereof is disclosed in Esch U.S. Pat. No. 5,754,717 as shown in FIG. 1 of this application, which patent is commonly assigned to the present assignee, and the disclosure of which is incorporated herein by reference. There is illustrated an optical fiber leading end 10 having a diffuser portion 12 comprised of the stripped core of a typical optical laser, an optical coupling layer, and an outer or alignment sleeve 14 . The optical coupling layer, replacing a part of the cladding and the buffer layer of the optical fiber, has an index of refraction exceeding that of the core so as to draw the light out of the core using well-known physical principles. The alignment sleeve is abraded, or roughened, in order to conduct light from the optical coupling layer to the exterior, while heat staking or ultrasonic welding is used to apply or attach the portion of 14 a of the outer sleeve 14 covering the diffuser tip to a further separate portion 14 b of the sleeve located towards the end of the optical fiber.
In essence, the method of forming the diffusion portion of the optical fiber illustrated in FIG. 1 representing the Esch patent, necessitates the presence of a weld joint 16 near the distal end of the remaining cladding. Producers of optical fibers with diffuser portions intended for this or similar surgical purposes are required to ensure an adequate mechanical strength of the fiber for the intended application, and in which the weld joint can result in a stress concentration reducing the strength of the optical fiber. It is also possible that silicone or adhesive from the optical coupling layer may contaminate the area of the sleeve junction during assembly, thereby weakening the weld joint. While the weld joint is deemed to be of adequate strength for most surgical applications, designers would like to use smaller-sized optical fibers. As the diameter of optical fibers become smaller, the degradation in strength of the optical fiber caused by the presence of the weld joint becomes more pronounced and resultingly important. The smaller diffusers can readily break or become detached at the weld joint; whereas the weld scam at the weld joint can catch on instruments and interfere with the medical procedure, thereby creating a nuisance, if not an operating danger for the surgeon.
Other publications which disclose various constructions and types of optical fiber arguments which may be applicable to surgical procedures and treatments employing laser illumination are widely known in the technology.
Anderson et al. U.S. Pat. No. 5,814,041 pertains to an optical radiator and laser fiber in which the distal or leading end sleeve portion of the optical fiber is attached to a second sleeve portion so as to form a weld or contact seam therebetween.
Evans et al. U.S. Pat. No. 5,802,229 discloses a fiber optic radiation system which, similar to Esch, does not provide for a continuous, unitarily constructed outer sleeve for the optic fiber.
Bruce U.S. Pat. No. 5,534,000 discloses a laser fiber apparatus wherein the leading or ablation end of an optic fiber is provided with a relatively short outer tube element so as form an essentially non-continuous sleeve surface providing a seam-like joint or step.
Similarly, Doiron et al. U.S. Pat. Nos. 5,269,777 and 5,196,005; and McCaughan, Jr. U.S. Pat. Nos. 4,693,556 and 4,660,925, disclose various types of optical fibers with light diffusers or similar structures; however, none of which evidence the continuous single-piece outer sleeve of seamless length as provided for by the present invention, nor the method of forming thereof.
SUMMARY OF THE INVENTION
Accordingly, the design of an optical fiber with a diffuser portion including an outer sleeve wherein the weld joint is eliminated is highly advantageous in constructing the sleeve of the optical fiber extending as one continuous, uninterrupted or unitary piece from the connector for a light source to the distal end of the core.
Pursuant to the invention, a medical instrument comprises a source for a laser light wherein an optical fiber with a diffuser portion at its distal end has the outer sleeve of the optical fiber constituted of a continuous unitarily-constructed tube extending from the connector for the laser-light source to at least the distal end of the core in the optical fiber. The sleeve of the optical fiber also contacts and supports the optical fiber at the leading or light emitting distal end thereof.
Accordingly, it is an object of the present invention to provide a method of producing an optical laser fiber arrangement in which the outer tubular sleeve encompassing the fiber core is of a continuous, unitarily constructed and seamless tubular structure.
Another object of the present invention is to provide a medical instrument incorporating an optical laser fiber produced in accordance with the inventive method for forming the optical fiber portion of the instrument.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference may now be made to the following detailed description of preferred embodiment of the invention, taken in conjunction with the accompanying drawings; in which:
FIG. 1 illustrates a longitudinal sectional view of an optical fiber utilizing the diffuser portion as shown in the Esch U.S. Pat. No. 5,754,717, representative of the prior art;
FIG. 2 illustrates a schematic representation of a laser device utilizing the optical fiber pursuant to the present invention;
FIG. 3 illustrates a diagrammatic perspective view of an optical fiber assembly incorporating an embodiment of the present invention;
FIG. 4 illustrates a longitudinal sectional view of the inventive optical fiber utilizing a diffuser portion, showing as represented from the interior to the exterior thereof, a core, an optical coupling layer, and an outer sleeve contacting the core distal to the diffuser portion;
FIG. 5 illustrates a fragmentary sectional view showing the annulus material containing a light-scattering component;
FIG. 6 illustrates a longitudinal sectional view showing the annulus assembled to the core prior to implementing the tipping step in an optical fiber utilizing the inventive diffuser portion, and
FIG. 7 illustrates a longitudinal sectional view of an embodiment of an optical fiber utilizing the inventive diffuser portion showing, as represented from the interior to the exterior, a core, an optical coupling layer, and an outer sleeve contacting the core distal to the diffuser portion.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring in detail to the drawings, for purposes of this description, “proximal” refers to a section on the inventive optical fiber 28 closer to a source of light energy 22 , and “distal” refers to a section on the optical fiber which is further away from the source of light energy 22 .
Illustrated schematically in FIG. 2 is a medical instrument 20 for diffusing light from an optical fiber 28 . The medical instrument 20 includes a source of light energy 22 , preferably a laser; and wherein the optical fiber 28 connects into the source of light energy 22 through the intermediary of a connector 18 which is attached to a connection port 24 leading to a diffuser portion 19 of the optical fiber. A typical connector and connection port of this kind which can be utilized for the medical instrument 20 is described in Evans et al. U.S. Pat. No. 5,802,229, while a typical laser employable for the medical instrument 20 is the Optima laser which will be sold by Ethicon Endo-Surgery in Cincinnati, Ohio. The optical fiber 28 with the attached connector 18 can be provided and sold separately from the source of light 22 , as an optical fiber assembly 29 , as represented in FIG. 3 of the drawings.
A typical optical fiber 28 according to one embodiment of the present invention, including diffuser portion 19 and a proximal light-transmitting portion 34 is shown in FIG. 4 . In a light-transmitting portion 23 of the optical fiber 28 , a cladding 32 and the proximal portion 34 of a sleeve 38 radially surround the proximal portion 30 of a core 31 . The optical fiber 28 may also have a buffer layer 42 arranged to extend circumferentially between the cladding 32 and the sleeve 38 . The material used to form the cladding 32 has an index of refraction lower than the index of refraction of the material-used to create the core 31 so as to contain the light within the core 31 . The core 31 , in addition to its proximal portion 30 , extends through a distal portion 36 to the distal end 52 thereof. The distal portion 36 of the core 31 which is employed to diffuse light, is surrounded by an optical coupling layer 40 and the distal portion 44 of the sleeve 38 . There is no interruption, discontinuity, or weld joint on the sleeve 38 inasmuch as the proximal portion 34 of the sleeve 38 and the distal portion 44 of the sleeve 38 are two segments of one continuous unitarily constructed sleeve 38 . The sleeve 38 can extend distally past the distal end 52 of the core 31 and may be configured to penetrating tip 50 . The sleeve 38 , as mentioned, is constituted of one continuous piece, preferably consisting of perfluoroalkoxy impregnated with barium sulfate.
A material having an index of refraction higher than the index of refraction of the core 31 forms the optical coupling layer 40 , wherein UV50 Adhesive, available from Chemence, Incorporated, in Alpharetta, Ga., can be used to produce the optical coupling layer 40 .
A light-scattering component 48 which is filled with a light-scattering material and located on the distal face 52 of the core 31 can reflect light back into the core 31 so as to provide a more even or uniform light distribution, whereby alexandrite can be employed as the light-scattering material for component 48 . In addition to its light-scattering properties, the material fluoresces in a temperature-dependent manner upon being stimulated by light, with this property adapted to be used to measure temperature in tissue in proximity to the diffuser portion 19 . The same adhesive which is employed for the optical coupling layer 40 can suspend the alexandrite particles therein and can serve as the base material for the light-scattering component 48 .
As illustrated in, respectively, FIGS. 4 and 7, utilizing the light-scattering component 48 , the sleeve 38 is shaped to extend distally past the light-scattering component 48 and resultingly forms a pointed penetrating tip 50 .
During operation of the medical instrument 20 , light generated by the source of light energy 22 travels through the core 31 to the diffuser portion 19 . There, in the embodiment of the invention illustrated in FIG. 4, light energy emerges from the core 31 to the optical coupling layer 40 because of the optical coupling layer having a higher index of refraction. The distal portion 44 of the sleeve 38 which surrounds the optical coupling layer 40 , collects the light from the optical layer 40 , employing the abrasions formed on the inner surface of the distal portion 44 of the sleeve 38 . The sleeve 38 preferably uses barium sulfate particles scattered within the sleeve 38 to direct light energy evenly outwards towards the tissue. Light energy reaching the light-scattering component 48 is reflected back towards the core 31 by the alexandrite particles in the light-scattering component 48 . Moreover, the fluorescent properties of the alexandrite particles, when stimulated by light energy of the proper wavelength, can determine the temperature of surrounding tissues employing methods which are known in the art. The penetrating tip 50 is capable of piercing tough tissue in order to assist medical procedures.
The inventive sleeve 38 has no weld joints or discontinuities in the outer diameter extending from the proximal end of the penetrating tip 50 to the connector 18 which conceivably tend to weaken the optical fiber 28 , or which may detrimentally catch or drag the optical fiber 28 so as to displace the latter while in use. When using the optical fiber 28 , surgeons or medical practitioners often need to bend it to successfully locate the fiber in the body of a patient. The optical fiber 28 and the associated sleeve 38 can withstand more bending than optical fibers with sleeves which have weld lines or discontinuities formed in the outer diameter thereof proximal to the penetrating tip 50 .
Method of Forming the Optical Fiber
In order to produce an optical fiber according to the invention as shown in FIG. 4, there can be modified an optical fiber 28 with its associated sleeve 38 . First, a sleeve 38 is provided which is approximately as long as the optical fiber to be used, and preferably long enough to extend from the connector 18 (shown in FIG. 3) past the distal face 52 of the core 31 . Thereafter, the inner surface of the distal portion 34 of the sleeve 38 is abraded. Different methods can be used to abrade, texture, or roughen the inner surface, such as brushing with a small brush, roughening with a small tool, or pressing against a mandrel to mold in rough areas, can all be employed in order to create a rough inner surface. The roughening process can be implemented while the sleeve 38 is a separate piece before its assembly with the other components of the optical fiber 28 , or it can be effected subsequent to assembly. In case the roughening process is performed after assembling the sleeve to the fiber, the sleeve 38 is slid over the buffer layer 42 so as to extend the sleeve 38 distally beyond the distal end of the buffer layer 42 and core 31 . Moving the sleeve 38 distally beyond the distal end of the buffer layer 42 and core 31 will expose the interior of the sleeve 38 so that it can be easily abraded.
After abrading, in order to prepare the optical fiber 28 for assembly, the distal portion 36 of the core 31 is exposed by stripping away the buffer layer 42 and the surrounding cladding 32 . Leaving the cladding 32 so as to extend distally beyond the end of the buffer layer 42 in a stepped manner, as shown in FIG. 4, reduces the formation of any stress concentration points.
In order to make the light-scattering component 48 , a mix of alexandrite particles and uncured adhesive, preferably in a ratio of 2.5 to 1 of alexandrite to adhesive by weight, is conveyed into a tube material used for annulus 46 , and having an inner diameter which is equal to the outer diameter of the core 19 . The annulus material should be long enough to extend well beyond the end of the sleeve 38 upon assembly. The mix of uncured light-scattering component material is an axial length of annulus material 46 containing the light-scattering component 48 , as shown in FIG. 5 .
The sleeve 38 is then slid over the prepared core 31 and buffer layer 42 until the sleeve 38 extends beyond the distal face 52 of the core 31 . Uncured adhesive 53 is then applied to the empty volume or space left by the buffer layer 42 and cladding 32 having been previously removed. The sleeve 38 is moved so as to extend the core 31 slightly beyond the end of the sleeve 38 , and the length of annulus material containing the uncured light-scattering component material is then fitted over the end of the exposed core 19 . The light-scattering component material should abut the distal face 52 of the core 19 and a small length of annulus material should surround the core 19 near its distal face 52 . The core 31 , the light-scattering component material, and a length of annulus material are then recessed or withdrawn into the sleeve 38 , leaving a length of annulus material extending beyond the distal face 52 of the core 31 , and substantially the same distance beyond face 52 as sleeve 38 , illustrated in FIG. 6 . In case no light-scattering component 48 is needed, the length of annulus material without the light-scattering component 48 is positioned around the core 31 near its distal face 52 .
In an optional step, there may be removed any air bubbles which may be present in the optical coupling layer 40 . The distal end of the optical fiber 28 with the distal face 52 of the core 31 is held down while being heated to allow the adhesive that will form the optical coupling layer 40 to flow towards the distal end under the effect of gravity. This step will assist in eliminating air from the optical coupling layer 40 in order to allow it to transmit light from the core 31 more efficiently, whereby, for instance, heat can be applied with a heat gun.
With the annulus material in place, the adhesive and the light-scattering component material are cured to form the optical coupling layer and light-scattering component 48 whereby pursuant to one embodiment of the invention, the adhesive can be cured by means of ultraviolet light.
The penetrating tip 50 is formed by placing the distal end of the optical fiber into a mold and heating it to melt and fuse the sleeve 38 and the annulus 46 into one piece, producing the embodiment shown in FIG. 4, leaving a small air pocket 51 in conjunction with the light-scattering component 48 .
In one embodiment of the invention, both the annulus 46 and the sleeve 38 are made of the same material and formed into one piece so that the annulus 46 becomes a part of the sleeve 38 once the parts are melted and fused. The annulus 46 , as a portion of the sleeve 38 , contacts the core 31 at the distal portion 36 of the core. It also contacts and aligns the light-scattering component 48 upon use of the light scattering component 48 . The penetrating tip 50 being formed on the optical fiber 28 , referred to as tipping, completes the diffuser portion 19 on the optical fiber 28 .
Another method of forming an embodiment of the optical fiber pursuant to the invention produces the configuration shown in FIG. 7 . In order to produce this embodiment, the cladding 32 and the buffer layer 42 are first stripped from the core 31 , as described in the previous method. The distal portion 44 of the sleeve 38 is abraded as before. The sleeve 38 is then displaced so as to extend past at least the distal face 52 of the core 31 . Using an adhesive which is curable into an optical coupling layer 40 , the void left by the removed buffer layer 42 and cladding 32 is then filled. If the light-scattering component 48 is used, the light-scattering component 48 is pushed through the uncured adhesive to the distal face 52 of the core 31 . In order to close the end of sleeve 38 , the sleeve end is heated in a mold which forces the sleeve 38 radially towards the core 31 to thereby form the embodiment shown in FIG. 7, with the sleeve 38 connecting the core 31 and the light-scattering component 48 , and air pocket 51 formed within tip 50 . The adhesive is cured into the optical coupling layer 40 , whereby in one embodiment of the intention, ultraviolet light can be used to cure the adhesive.
It is readily apparent that equivalent structures may be substituted for the structures illustrated and described herein and that the described embodiments of the invention are not limited to those elucidated. As one example of an equivalent structure which may be used, the optical coupling layer 28 can comprise a substance filled with light-scattering particles, which if employed eliminates need to abrade the inner surface of the sleeve 38 .
While the invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing form the spirit and scope of the invention.
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A novel optical fiber, and a method for its production, having a diffuser portion and continuous unitarily-constructed outer sleeve, which is adapted for the transmission of light to a treatment locale. More particularly, a medical instrument has an optical fiber including a diffuser portion at a distal end wherein an alignment sleeve for the optical fiber extends uninterruptedly in a single piece from a connector for a laser light source to at least the distal end of the core of the optical fiber.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a method and apparatus for transmitting data packets in a packet stream over an unreliable channel, and, in particular, to transmitting data packets having compressed headers.
2. Description of the Related Art
Several communication technologies exist for transmitting data from one terminal to another terminal. The most commonly used techniques are cellular telephony and the Internet. Further developments are media-on-demand and conversational services such as Internet telephony. Most of these services require the transport of real-time data including audio and video contents.
The Real-time Transport Protocol (RTP) provides means for such purposes. RTP is an Internet protocol for transmitting data in real-time or nearly real-time. RTP itself does not guarantee real-time delivery of data, but does provide mechanisms for the sending and receiving of applications to support streaming data. Typically, RTP runs on top of the UDP protocol. UDP (User Datagram Protocol) is a connectionless protocol that, like TCP, runs on top of IP networks. Unlike TCP/IP, UDP/IP provides no error recovery services, but instead offers a direct way to send and receive datagrams over an IP network.
While RTP has been developed for fixed networks, RTP may nevertheless be used in mobile networks. However, one problem in using RTP over mobile networks is the limited bandwidth in the mobile channel. This is because each of the protocols RTP, UDP and IP has its own header. A packet will then, in addition to link layer framing, have an IP header of 20 bytes, a UDP header of 8 bytes, and an RTP header of 12 bytes, thus summing up to at least 40 bytes.
This header is highly redundant, and to decrease the amount of overhead, header compression mechanisms have been developed. Header compression protocols remove the redundancy of the header and encode the information in an efficient way. This may lead to a compression of the original header down to one byte in the best case.
A system using a header compression protocol is illustrated in FIG. 1 . The transmitter comprises a compressor 100 which is used for compressing the original header. The compressed header is then transmitted to the receiver and is there decompressed by the decompressor 110 .
The context 120 is the state which the compressor 100 uses to compress the header. The context is a set of variables and consists basically of an uncompressed version of the header fields of the last header. Besides the actual header fields, the context comprises additional variables, such as first order differences of header fields that have been detected to be constant for a series of successive packets. The context can also contain additional information describing the packet stream, for example, the typical inter-packet increase in sequence numbers or timestamps.
In operation, the compressor 100 and the decompressor 110 are required to maintain a common context. When the context 130 of the decompressor 110 is not consistent with the context 120 of the compressor 100 , header decompression will fail. This situation can occur when data packets are transmitted over unreliable, e.g. wireless, channels because packets may then be lost or damaged between the compressor 100 and the decompressor 110 .
It is therefore necessary to initiate a resynchronization procedure once the context 130 of the decompressor 110 has become invalid. For this purpose, update (UP) packets are provided for transmitting information contained in the context 120 of the compressor 100 to the decompressor 110 . Thus, by using UP packets, the context 130 is updated.
The performance of a header compression scheme can be described with two parameters, compression efficiency and robustness. A robust scheme tolerates errors on the link over which header compression takes place without losing additional packets, introducing additional errors or using more bandwidth. Using UP packets increases on the one hand the robustness, but decreases compression efficiency, since UP packets are large in size. Therefore, in addition to UP packet, non-update (NUP) packets are used which are very small and which only depend on the previous UP packet. Thus, NUP packets do not update the context so that, if a NUP packet gets lost, the context 130 of the decompressor 110 continues to be valid, so that the receiver is still able to decompress the following packets.
The packet stream to be compressed usually behaves very regularly. Most of the header fields are constant and do not change during the life-time of the stream. Some fields do change with each packet (e.g. sequence number and timestamp). If the values of these fields are synchronized to the sequence number and thus can be calculated from this number, the stream is regular. Irregularities in these fields disturb this synchronization, e.g. because of a non-linear jump in the RTP-timestamp field. With an irregularity, it is not possible to calculate the values of the changed fields from the sequence number. These irregularities might occur quite frequently, e.g. on the average of every second for a conversational audio stream.
In case an irregular change has occurred, information about the irregular change has to be transmitted to the decompressor. Therefore, either UP or NUP packets have to be extended by this information. This can, for instance, be done by setting an extension bit in the header and by placing the irregularity information into a predefined extension field of the header. However, using extended UP (extUP) packets decreases the robustness, while using extended NUP (extNUP) packets decreases the compression efficiency.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the above situation. Accordingly, a primary object of the present invention is to provide a method and apparatus for transmitting data packets in a packet stream, where the method and apparatus are capable of improving both the compression efficiency and packet stream robustness.
It is another object of the present invention to allow for determining the optimum conditions for both compression efficiency and packet stream robustness.
It is still another object of the present invention to allow for dynamically adapting the transmission scheme to the channel and packet stream properties.
A further object of the present invention is to reduce the mean header size even when irregular changes of the packet stream occur.
Another object of the present invention is to allow for sending extNUP packets in case the irregular change is only valid for a short number of packets. This is because if extUP packets were used in the case of a short irregularity, the decompressor's context would be easily invalidated and the decompressor would not be able to decompress all subsequent packets until a new UP packet is received correctly. That is, it is an object of the present invention to increase the packet stream robustness as compared with a transmission scheme in which irregularities are transmitted in extUP packets only.
Yet another object of the present invention is to increase the compression efficiency by avoiding using extNUP packets. As the number of NUP packets is usually greater than the number of UP packets, it is the object of the present invention to send extUP packets wherever possible.
These and other objects of the present invention will become more apparent hereinafter.
To achieve these objects, according to a first aspect of the present invention, there is provided a method of transmitting data packets in a packet stream, where the data packet have compressed headers. The method comprises the steps of compressing a header using a context, transmitting at least one update packet containing data indicating the context, and transmitting at least one non-update packet. The method further comprises the steps of detecting an irregular change of the packet stream, obtaining at least one packet stream parameter, and transmitting either an extended update packet or an extended non-update packet depending on the determined (obtained) packet stream parameter, where the extended packet includes information about the irregular change.
According to a second aspect, the invention provides an apparatus for transmitting data packets in a packet stream, where the data packets have compressed headers. The apparatus comprises a compressor for compressing a header using a context, transmission means for transmitting a least one update packet containing data indicating the context and at least one non-update packet, detection means for detecting an irregular change of the packet stream, and control means for obtaining at least one packet stream parameter and controlling the transmission means to transmit either an extended update packet or an extend non-update packet depending on the determined (obtained) packet steam parameter, where the extended packet includes information about the irregular change.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are incorporated into and form a part of the specification to illustrate several embodiments of the present invention. These drawings together with the description serve to explain the principles of the present invention. The drawings are only for the purpose of illustrating preferred and alternative examples of how the present invention can be made and used and are not to be construed as limiting the present invention to only the illustrated and described embodiments. Further features and advantages will become apparent from the following and more particular description of the various embodiments of the invention, as illustrated in the accompanying drawings, wherein:
FIG. 1 illustrates a compressor/decompressor system, in which UP and NUP packets are used;
FIG. 2 is a flowchart illustrating the process of deciding when to transmit extUP or extNUP packets according to the present invention;
FIG. 3 is a flowchart illustrating the process of estimating the maximum number of consecutive packet loss according to a preferred embodiment of the present invention; and
FIGS. 4 a and 4 b are flowcharts illustrating preferred embodiments of the process of estimating the number of packets for which the irregular change is valid.
DETAILED DESCRIPTION OF THE INVENTION
The illustrative embodiments of the present invention will be described with reference to the drawings wherein like elements and structures are indicated by like reference numbers. Preferred embodiments of the present invention will be described in more detail hereinafter.
As will be apparent from the discussion below, the present invention makes use of at least one packet stream parameter. Packet stream parameter means any channel, packet stream and compressor-state property which can at least indirectly provide some information that might be suitable for deciding when and how to send information about an irregular change to the decompressor. In the preferred embodiments, the following parameters are used:
N 1 : the number of packets that have been sent since the last update sequence;
N 2 : the maximum number of consecutive packet loss over the channel, i.e. the maximum number of consecutively lost packets in the packet stream; and
N 3 : the number of subsequent packets of the stream for which an irregular change is valid, i.e. the time length of an irregularity in units of data packets.
Referring now to FIG. 2 , in deciding when to use extUP packets and when to use extNUP packets, the compressor 100 first determines in step 200 whether an irregular change of a packet stream has occurred. If no irregular change has occurred, there is no need to transmit extended packets at all, and the process returns. However, if it is determined in step 200 that an irregular change of a packet stream has occurred, the compressor 100 checks two separate conditions for deciding which packets to extend.
In checking the first condition, the compressor 100 obtains the parameter N 1 in step 210 . Then, the parameter N 2 is retrieved in step 220 . The parameter N 2 may, for instance, have previously been estimated by using the process which is described below in the context of FIG. 3 . The compressor 100 then can simply retrieve the parameter from a storage unit or any other kind of data buffer.
Once the parameters N 1 and N 2 have been obtained, the compressor 100 performs a comparison between these values in step 230 . If the parameter N 1 is not greater than the parameter N 2 , it is decided in step 270 to transmit extNUP packets. Otherwise, the process continues with step 240 .
In checking the second condition, the compressor 100 retrieves the parameter N 3 in step 240 , again by accessing previously estimated values. It is then determined in step 250 whether N 2 exceeds N 3 . If it is determined that N 2 exceeds N 3 , it is again decided to transmit extNUP packets to the decompressor 110 . Otherwise, the decompressor 110 will, in step 260 , receive information about the irregular change via extUP packets.
Thus, extended UP (extUP) packets are transmitted only if both conditions 230 , 250 are fulfilled. If at least one of conditions 230 , 250 is not met, it is decided to transmit extNUP packets.
By this process, compression efficiency is increased because the irregular change is not transmitted in all packets, i.e. no larger extNUP packets have to be transmitted after the new context is established. Further, by sending extUP packets whenever necessary, robustness is increased.
While it has been described that condition 230 is checked before condition 250 in discussing FIG. 2 , it will be appreciated by those of ordinary skill in the art that condition 250 may be alternatively checked first.
Preferably, the number of extUP packets in one sequence is adapted in step 260 to the parameter N 2 , for reliably establishing the irregularities in the decompressor's 110 context 130 . In a preferred embodiment, the number of extUP packets is set to be equal to N 2 .
As mentioned above, the parameters N 2 and N 3 are preferably retrieved in steps 220 and 240 from any kind of storage unit, and these parameters have to be previously estimated. While FIG. 3 illustrates a preferred embodiment of estimating the parameter N 2 , the generation of N 3 estimates will be described in the context of FIGS. 4 a and 4 b.
Referring now to FIG. 3 , the estimation of the maximum number of consecutive packet loss is based on non-acknowledgement (NACK) packets that are sent from the decompressor 110 to the compressor 100 . NACK packets are sent if an invalid context has been detected by the decompressor 110 due to a UP packet loss. The invalid context is detected upon reception of the first NUP packet which contains a sequence indication bit that is unequal to the one stored in the decompressor's 110 context 130 .
In step 300 , the compressor 100 receives a NACK packet or message from the decompressor 110 and extracts the sequence number of the last correctly decompressed packet, i.e. where the context was still valid, from this NACK message (step 310 ). Then, the compressor 100 obtains the current sequence number in step 320 . From the extracted and the current sequence numbers, the compressor 100 is able to calculate the amount of packets which were sent to the decompressor 110 between the transmission time of the last correctly received packet and the reception time of the NACK message. In step 330 , the compressor 100 obtains the Round Trip Time (RTT) which is, in this case, the time that is required to trigger and receive the NACK message. Then, the compressor 100 subtracts the obtained RTT value from the calculated amount of packets, thereby calculating the number of packets which were lost consecutively (step 340 ). This number is then made accessible to the compressor 100 as the parameter N 2 .
The estimation of N 3 is preferably done as depicted in FIGS. 4 a and 4 b . While knowledge about the used codec and its properties is used in the process of FIG. 4 a , the process of FIG. 4 b includes observing the packet stream and gaining estimations for the future from the experiences of the past. It will be appreciated by those of ordinary skill in the art that the processes of FIGS. 4 a and 4 b may be used alternatively as well as in combination.
In FIG. 4 a , the compressor 100 knows the properties of different streams coming from different codecs. This information can be stored in a look-up table of the compressor 100 . In step 400 , the compressor checks the RTP Payload Type field of the header to know which is the codec being used. Then, the compressor 100 retrieves the necessary information about the codec from the look-up table in step 410 and calculates the parameter N 3 by using the retrieved information (step 420 ).
In the process of FIG. 4 b , the compressor 100 retrieves in step 440 observed packet stream properties such as the maximum, minimum, average, variance of the average, etc, of the number of packets for which an irregular change is valid. These properties are preferably stored in a memory of the compressor 100 . From this information, the compressor 100 calculates in step 450 an estimation of the parameter N 3 which depends on the degree of robustness one would like to have. Wishing a higher robustness implies that the chosen value is to be near the minimum number of packets.
As apparent from FIGS. 3 , 4 a and 4 b , the estimation processes further include a step 350 , 430 of applying a safety factor. This is to take into account that the calculated values of parameters N 2 and N 3 are only estimates. Thus, in order to ensure the robustness of the scheme, the estimated parameter N 3 is preferably divided by the safety factor which is greater than one, while the estimated parameter N 2 is preferably multiplied with this factor.
As will be appreciated by those of ordinary skill in the art, according to the present invention, a decision is made whether to send extUP or extNUP packets, based on at least one packet stream parameter. Thus, the present invention allows for determining the optimum conditions for both compression efficiency and packet stream robustness by dynamically adapting the transmission scheme to the channel and packet stream properties. This reduces the mean header size even when irregular changes of the packet stream occur.
While the present invention has been described with respect to the preferred physical embodiments constructed in accordance therewith, it will be apparent to those skilled in the art that various modifications, variations and improvements of the present invention may be made in the light of the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the present invention. In addition, those areas in which it is believed are familiar to those of ordinary skill in the art have not been described herein in order to not unnecessarily obscure the description of the present invention. Accordingly, it is to be understood that the present invention is not to be limited by the specific illustrative embodiments, but only by the scope of the appended claims.
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A method and apparatus for transmitting data packets in a packet stream wherein the data packets have compressed headers. Update packets containing data indicating a context used in compressing the headers, and non-update packets are transmitted. An irregular change of the packet stream is detected and at least one packet stream parameter is obtained. Dependent on the determined packet stream parameter, either an extended update packet or an extended non-update packet is transmitted, wherein the extended packets include information about the irregular change. In addition, the packet stream parameter is estimated and a safety factor is applied.
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FIELD OF THE INVENTION
The present invention relates to sheets of fibrous material, especially comprising cellulosic fibers, which are absorbent for aqueous liquids.
DESCRIPTION OF THE PRIOR ART
There is great demand for materials which are capable of absorbing quantities of liquid, while remaining substantially solid, and which, before use, are compact. Examples of uses for such materials include kitchen rolls, sanitary pads, nappies, plasters and wound dressings in general.
Suitable materials are generally available, but which do not necessarily fulfil all of the requirements. For example, sanitary pads may be too bulky or too solid, and surgical dressings do not absorb a sufficient quantity of exudate from the wounds. An added complication is that, for applications involving contact with the human or animal body, especially a wound, it is highly desirable that there be no toxic compounds present in the dressing which may affect the body in any way. This is a particular disadvantage of many plastics.
Various materials are known which can be used for the above applications. Such materials include foamed plastics, absorbent paper and, more recently, sheets of cross-linked cellulosic fibers.
One advantage of the cross-linked cellulosic fibers is their non-toxicity, provided that the cross-linker is a suitable non-toxic compound, such as carboxymethyl cellulose. These materials also have the advantage of being able to absorb up to about one hundred times their own weight in water.
A primary disadvantage of the cross-linked cellulosic materials arises through the various methods of production available for them. This is essentially because of the difficulties involved in evenly distributing the cross-linker precursor throughout the fibers before effecting cross-linking. Two basic methods are known, the first of which is a dry process, and the second is a wet slurry process.
In the dry process, a layer of suitable cellulosic fibers is generated, such as by the air-felt process, followed by dredging a suitable powdered cross-linker onto the sheet and then compressing the whole, optionally after agitation, together with heating. It is generally necessary to use great pressure in order to effect any kind of satisfactory permeation of the cross-linker through the sheet, and the result is a very densely compressed sheet with variable concentrations of cross-linker throughout. These sheets tend to be least absorbent.
The alternative, wet process involves making a slurry of the cellulosic fibers and the cross-linker. This slurry is dried out and formed into a sheet, and then compressed and heated as before. This results in a more even distribution of the cross-linker throughout the material, but still does not form an optimal material with a particularly even density of cross-linker throughout, and also suffers from the drawback of being time consuming. The main problem is clumping with materials prepared from slurries, even where relatively low quantities of cross-linker are used.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved process for the production of cross-linked cellulosic fibrous materials, which process will ensure that the materials have an even and consistent density of cross-linker throughout, and which process will also not necessarily be limited to bibulous fibers, whether they be cellulosic or other.
It is also an object of the invention to provide absorbent materials of cross-linked fibers, preferably cellulosic fibers, which display superior absorption properties to the known materials.
It has now been discovered that the objects of the invention are readily achievable by mixing of an aerated suspension of statically charged fibers with the cross-linker before heating and compressing, the resulting materials having a capacity for fluid absorption considerably greater than has been heretofore known for such materials.
Thus, the present invention provides, in a first aspect, a process for the production of absorbent materials, comprising preparing a layer of fibers and a cross-linker therefor, and heating and compressing, in either order or together, the layer thereby prepared so as to effect cross-linking of the fibers, characterized in that, before preparation of the layer, the fibers and the cross-linker, both of which are essentially dry, and the cross-linker being in the form of a fine powder, are blended after either or both of the cross-linker and fibers has been electrically charged.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying Figure shows apparatus suitable for the production of an absorbent layer of the invention.
DETAILED DESCRIPTION OF THE INVENTION
This process gives rise to an extremely even coating of cross-linker on the fibers, and the composite layer of fibers and cross-linker can then easily be compressed and heated to yield a superior end product. Furthermore, the process is extremely easy to use and effect, and is also cheap and quick, not requiring heavy compression rollers, or time consuming drying of a slurry.
A further advantage lies in the hygienic method of preparation of the product, as the constituents and process are essentially dry, thereby limiting the possibility of contamination.
In the process of the invention, it is generally preferred that the preparations are brought into admixture in a gaseous medium, preferably air.
Before compression, it is desirable to allow the mixture to settle into a layer after first bringing the preparations into admixture in a drum with agitation.
It is generally preferred that the fibers be suspended in air in a suitable container, such as a polyethylene or polypropylene drum, and charged. It is sufficient, for example, to merely provide a quantity of fibers in a polyethylene bag, to inflate the bag, and then to shake or agitate the bag so as to charge the fibers. Once this has occurred, the powdered cross-linker can be introduced to the bag and shaken again, after which the bag can be emptied onto a suitable surface, and-the resulting layer heated and compressed.
On a larger scale, the fibers could be provided in a drum which, in turn, could be rotated until such time as the fibers therein were sufficiently charged. The cross-linker could then be introduced, with the drum rotated further, and then the mixture allowed to settle into the composite layer.
In a further aspect, the present invention provides apparatus for the production of absorbent materials from an essentially dry preparation of fibers and an essentially dry preparation of a powdered, heat activatable cross-linker for the fibers, the apparatus comprising a drum having a top, a bottom and walls defining a cavity of the drum;
the top of the drum having a first at least one opening through which the fibers can be introduced;
the top of the drum having a second at least one opening through which the cross-linker can be introduced;
dividing means being located between the first and the second openings, the dividing means extending toward the bottom of the drum, and preferably forming a funnel;
electrical charging means being provided on the wall of the drum at a position below the first at least one opening and above the lowest extent of the dividing means;
means for introducing gas under pressure being provided on the wall of the drum at a position below the first at least one opening and above the lowest extent of the dividing means;
means, such as a propellor or fan blade, to disperse the cross-linker and the fibers to form a dispersion when the cross-linker falls below the lowest extent of the dividing means;
the bottom of the drum defining an opening through which the dispersion can pass;
a fine mesh conveyor being located beneath the bottom of the drum to collect the dispersion;
collecting means being disposed beneath the conveyor to collect any excess cross-linker falling through the conveyor;
means to heat the dispersion after collection on the conveyor; and
means to compress the dispersion after collection on the conveyor, the heating and compressing means optionally being provided together in one or more rollers, for example.
The fibers may also be charged by other suitable means, such as providing charging plates directly linked to an electrical source, or by using ionizing radiation. It is also not necessary to suspend the fibers in air, especially if either of these latter two methods is used, and the powdered cross-linker can be introduced to the layer of fibers which then need only be agitated sufficiently to allow an even distribution of the cross-linker throughout the fibers, the electrical charge on the fibers serving to attract the cross-linker.
It is also not necessary for the fibers to be charged. It is possible for the powdered cross-linker to be charged instead, and then introduced to a suitable preparation of the fibers. Again, this may be a suspension in air, or may be a layer of fibers which are then agitated after the introduction of the cross-linker.
It is also possible to charge both the cross-linker and the fibers, but this is not required, and may possibly result in clumping of the cross-linker on the fibers if too much cross-linker is introduced.
It is also preferred to allow excess cross-linker to be separated from the composite layer before heating and compression. This may be effected by depositing the layer on a fine mesh, thereby allowing excess powder to fall through, and be collected for further processing if desired. The mesh itself may be agitated to assist loose powder to fall through, if desired. Owing to the charged nature of the layer and the powder, it may also be desirable to earth any container into which the powder falls. It is not so desirable for the mesh, as it may serve to prematurely discharge the composite layer, and allow the cross-linker to fall away from the fibers. In such an instance, an inferior product may be formed. However, it is generally the case that the charged condition of the composite layer exists for several minutes, allowing unhurried preparation of the layer for heating and compression before the charge wears off.
In some cases, it may be desirable to align the fibers in the material, and this may be achieved by any suitable means. One such means is by combing the material, such that the fibers must pass through a suitable array of slots, for example.
Other treatments of the composite layer may comprise spraying or immersion of the layer with water or any other, suitably aqueous, liquid, followed by drying which may be effected at the same time as the heating and compression. Such a treatment affects the end product, but is not usually desirable, unless, for example, the spray includes a dye, antiseptic or antibiotic. Even so, such substances may be added after cross-linking.
Before cross-linking, it may also be desirable to run the layer through a series of rollers, such as wet and dry heated rollers. Again, this affects the end product in a known manner.
Returning to the blending process, it is preferred to keep both cross-linker and the fibers as dry as possible, in order to maximize the effect of the electrical charge. To this extent, it may also be preferable to introduce a stream of warm dry air to displace humid air, or to dry the fibers and/or cross-linker. Further, it is not necessary that air is used, although if any other medium, such as an inert gas, or nitrogen, is used, then this will tend to raise the cost of production, and involve more expensive containment facilities. Nevertheless, use of such alternative media is envisaged by the present invention.
The present invention is particularly applicable to cellulosic fibers, but is not limited thereto. Any fibers may be used, provided that they are capable of being electrically charged. In particular, it is preferred that the fibers comprise polyhydric polymers, useful examples of which are naturally occurring structural polymers, particularly polysaccharides. Suitable examples include lignin, and especially cellulose.
It is not necessary that the fibers be bibulous, as it is generally envisaged that the majority of the absorption of the end product will be effected by the cross-linker matrix. However, it is preferred that the fibers be as fine as possible. This is for two reasons, the first being in order to avoid irritation where the material might come into contact with the human or animal body, and the second being to enhance the ability of the fibers to hold an electric charge. Nevertheless, it is envisaged that, provided that the fibers can hold an electric charge, then any gauge fibers may be used.
It is envisaged that, during the blending process, the powder of the cross-linker will evenly coat each individual fiber, subject to the amount of cross-linker present. Accordingly, it is preferred to prepare the cross-linker in such a manner that it forms a very fine dry powder. It is generally preferred that the mesh size of the powder be such that the powder will appear to float if a pinch of the powder is sprinkled in the air. In general, the cross-linking compounds available tend to be somewhat coarse, and it is preferred that they should be milled further before use.
There is no particular restriction on the nature of the cross-linker, provided that it can form a suitably fine powder for use in accordance with the process of the invention. Suitable cross-linkers may be those that form a gel with water, and examples include such compounds as gum arabic, starch, cellulose, hydroxypropyl cellulose, but especially carboxymethyl cellulose. This last is especially preferred where the end product is to comprise cellulose fibers.
It will be appreciated that the nature of the cross-linker will affect the properties of the end product. Such properties include the quantity of liquid which can be absorbed, as well as the rate at which the liquid is absorbed.
The materials produced in accordance with the present invention tend to have considerably superior absorptive qualities and, for example, a material which comprises essentially cellulose fibers and carboxymethyl cellulose (CMC) as cross-linker can absorb up to about 2,000 times its dry weight.
In the example given above, the rate of absorption tends to be extremely rapid (as little as a few seconds), and this may not always be desirable. If the material is to be used for a burn, for example, where the exudate only emerges slowly, then it may be desirable to tailor the material such that, while the overall capacity for absorbing liquid is substantially unchanged, the rate at which it will absorb the liquid is considerably reduced. Again, in the above example, this is suitably achieved with the addition of hydroxypropyl cellulose to the CMC. A proportion of about 10% hydroxypropyl cellulose to 90% CMC is generally suitable to slow the rate of absorption down such that capacity is only reached after about 24 to 48 hours.
It may also be desirable to provide a blend of substances to form the cross-linker for other reasons. In particular, while CMC is a particularly good absorptive agent, its cross-linking strength is not necessarily particularly high. A material comprising solely CMC and cellulose will hold together, even at full water capacity, but can fairly readily be broken up.
Thus, if required, a further substance can be introduced into the cross-linker powder, or pulve, to enhance the strength of the material. Again, the substance should be finely milled, and does not need to be able to provide an absorbent matrix in its own right. Suitable substances include low density thermoplastics, such as polyethylenes. These may be used in any suitable quantity, but the higher the proportion of the strengthening cross-linker, the lower the final absorptive capacity of the end product will be. A suitable range of strengthening cross-linker in the powder is between about 10% and 30%, with about 20% being preferred. When the layer is heated and compressed, the cross-linking will occur.
After the absorbent material has been prepared, it may be packaged in any suitable manner, or prepared as a dressing or nappy etc. It may be useful, for example, to provide back and front layers on the resulting sheet material, where the back layer is essentially a barrier to the passage of any liquid absorbed by the material, while the front layer is porous to allow liquid to be taken up. This is a particularly preferred embodiment, and is broadly applicable to most applications in which the materials of the invention can be used.
If the materials of the invention are to be applied as a dressing for a wound, for example, then adhesive may be applied to one face of the material, or to the porous layer which would separate the wound from the absorbent material.
It will also usually be preferable to seal the edges of the material to prevent any leakage of liquid out of the side of the product, and this may be achieved in any known manner, such as by the use of a binder or sealant. One method may involve stitching along the edge followed by sealing the stitching, if required, by a suitable sealant.
Suitable non-limiting examples of uses to which the materials of the invention may be put include: surgical sponges; incontinence pads; pledgers; eye pads; plasters; adhesive surgical dressings; impregnated wound dressings; ischaemic ulcer dressings; decubitus ulcer dressings; burn dressings; emergency accident packs; haemostatic dressings and, generally, human or animal applications.
It will also be appreciated that the absorbent materials of the invention may be employed in industrial situations, and may also useful provide insulation.
The materials of the invention may be defined as follows: an absorbent material comprising fibers cross-linked by a suitable cross-linker, characterized in that the cross-linker is associated with substantially the entire surface of each fiber.
More preferably, the materials of the invention comprise fibers cross-linked by a polyhydric cellulose derivative, and preferred cross-linkers comprise at least 50% carboxymethyl cellulose. It is most preferred that the fibers comprise natural structural polymers, the most preferred being cellulose.
The accompanying example is intended for illustration only.
EXAMPLE
ABSORBENT MATRIX
The components of the absorbent matrix are:
1. Cellulose fibers (OF), staple length 0.3 to 0.5 m;
2. Carboxymethyl cellulose (CMC) milled to pulve; and
3. LDPE Granules milled to pulve.
The constituents are:
100 g CF;
250 g Blanose CMC (BL); and
150 g LDPE granules milled to pulve.
Ten grammes of fine cellulosic fibers, staple length 0.3 mm, are placed in a hexagonal chamber, preferably made from polypropylene, polyethylene or nylon. The chamber is rotated on a long axis mechanically at speeds between 25 and 45 revolutions per minute, depending on the size of the chamber. In this example the chamber is 20 inches high, 10 inches in diameter and bottle shaped (Bench technique). The rotation agitates the fibers and creates an electrostatic charge to the fibers. The charged fibers are tested at intervals by stopping the rotation and placing a 20 inch plastic rod in the container, to see if the fibers are attracted to it. If they are attracted en masse, a few more minutes of agitation is required before the second phase is employed. The procedure usually takes between 10 and 15 minutes, but is very dependent on the surrounding environment and it may be necessary to introduce warm dry air into the chamber to speed the process.
When the fibers are judged to be correct in terms of the charge they are holding, 25-30 g of very finely ground carboxymethylcellulose (pulve) is introduced into the chamber, preferably through a very fine sieve, so as to form clouds of pulve in the chamber. The rotation is then started again between 5 and 10 revolutions per minute. The CMC pulve is attracted to the charged fibers after approx. 5 minutes, depending on thickness of coating required (different thicknesses of coating are used for different product requirements).
When the fibers are sufficiently coated for the product required, the agitation is stopped and the coated fibers are allowed to settle on a Teflon (Trade Mark) coated fine wire mesh positioned 0.5 inch (13 mm) above a metal alloy tray inserted through an aperture at the bottom of the chamber. The coated fibers are collected on the wire mesh and the unused pulve is allowed to pass through and is collected on the tray beneath. The chamber may need to be earthed to prevent the fibers from clinging to the interior.
The wire mesh is then removed with the fibers from the chamber and gently agitated so that the fibers lie flat on the mesh. A duplicate fine wire mesh is then gently laid on the exposed fibers, to sandwich them. The sandwich is then passed through a pair of preheated Teflon (Trade Mark) coated rollers, to effect cross-linking. The fine wire mesh is then removed from the fibers to leave a pad of material.
Thickness may be gauged by the weight of the fibers and CMC pulve introduced into the chamber. The rollers may be heated electronically to produce variable heat for different thicknesses. The temperatures required are usually between 300° F. and 400° F. (149° and 204° C.). Roller pressures are between 10 and 201b per square inch, speed of rollers is between 45 seconds and 60 seconds per square yard.
If necessary, the cellulose fibers may be positively charged and CMC negatively charged, thereby speeding the process and producing a better base material.
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The present invention relates to absorbent materials comprising fibers cross-linked by a suitable cross-linker therefor, and wherein said cross-linker is associated with substantially the entire surface of each fiber, said materials being preparable by mixing of an aerated suspension of the charged fibers with the cross-linker before heating and compressing, such fibers having a capacity for fluid absorption considerably greater than has been heretofore known for such materials.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 62/093,372, filed Dec. 17, 2014. The content of the aforementioned application is incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the present disclosure generally relate to data analytics. More specifically, embodiments presented herein relate to generating a learning model of user interests based on image or video metadata.
[0004] 2. Description of the Related Art
[0005] Individuals take images to capture personal experiences and events. The images can represent mementos of various times and places experienced in an individual's life.
[0006] In addition, mobile devices (e.g., smart phones, tablets, etc.) allow individuals to easily capture both digital images as well as record video. For instance, cameras in mobile devices have steadily improved in quality and are can capture high-resolution images. Further, mobile devices now commonly have a storage capacity that can store thousands of images. And because individuals carry smart phones around with them, they can capture images and videos virtually anywhere.
[0007] This has resulted in an explosion of multimedia content, as virtually anyone can capture and share digital images and videos via text message, image services, social media, video services, and the like. This volume of digital multimedia, now readily available, provides a variety of information.
SUMMARY
[0008] One embodiment presented herein describes a method for inferring user interests based on metadata of a plurality of multimedia objects captured by a plurality of users. The method generally includes receiving, for each of the users, metadata describing each multimedia object in the plurality of objects associated with that user. Each multimedia object includes one or more attributes imputed to that object based on the metadata. The method also includes identifying one or more concepts from the one or more attributes. Each concept includes at least a first attribute that co-occurs with a second attribute imputed to a first multimedia object. The method also includes associating a first one of the plurality of users with at least one of the concepts based on the attributes imputed to multimedia objects associated with the first one of the plurality of users.
[0009] Other embodiments include, without limitation, a computer-readable medium that includes instructions that enable a processing unit to implement one or more aspects of the disclosed methods as well as a system having a processor, memory, and application programs configured to implement one or more aspects of the disclosed methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments.
[0011] FIG. 1 illustrates an example computing environment, according to one embodiment.
[0012] FIG. 2 further illustrates the mobile application described relative to FIG. 1 , according to one embodiment.
[0013] FIG. 3 further illustrates the analysis tool described relative to FIG. 1 , according to one embodiment.
[0014] FIG. 4 illustrates an example user interest taxonomy, according to one embodiment.
[0015] FIG. 5 illustrates a method for generating a user interest taxonomy, according to one embodiment.
[0016] FIG. 6 illustrates a method for building a predictive model for inferring user interests, according to one embodiment.
[0017] FIG. 7 illustrates a method for inferring user interests based on a predictive model, according to one embodiment.
[0018] FIG. 8 illustrates an application server computing system, according to one embodiment.
[0019] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
DETAILED DESCRIPTION
[0020] Embodiments presented herein describe techniques for inferring user interests from metadata associated with digital multimedia (e.g., images and video). Digital multimedia provides a wealth of information which can be evaluated to determine a variety of valuable insights about individuals taking images. For example, assume an individual takes pictures at a golf course using a mobile device (e.g., a smart phone, tablet, etc.). Further, assume that the pictures are the only indication the individual was at the golf course (e.g., because the individual made only cash purchases and signed no registers). Metadata associated with this image can place the individual at the golf course at a specific time. Further, event data could be used to correlate whether there was going on at that time (e.g., a specific tournament). Such information may be useful to third parties, e.g., for targeted advertising and recommendations.
[0021] However, an advertiser might not be able to identify an effective audience for targeting a given product or service based on such information alone. Even if image metadata places an individual at a golf course at a particular point of time, the advertiser might draw inaccurate inferences about the individual. For example, the advertiser might assume that because the metadata places the individual at a high-end golf course, the individual is interested in high-end golf equipment. The advertiser might then recommend other high-end equipment or other golf courses to that individual. If the individual rarely plays golf or does not usually spend money at high-end locations. Such recommendations may lead to low conversion rates for the advertiser. Historically, advertisers have been generally forced to accept low conversation rates, as techniques for identifying individuals likely to be receptive to or interested in a given product or service are often ineffective.
[0022] Embodiments presented herein describe techniques for inferring user interests based on metadata of images (e.g., digital photos). Specifically, embodiments describe building a predictive model used to infer interests for a user. In one embodiment, a multimedia service platform provides a software development kit (SDK) that third parties (e.g., retailers, marketers, etc.) may use to build mobile applications that extracts metadata from digital multimedia captured and stored on a mobile device. The metadata may describe where and when a given image was taken. The mobile application can use APIs included in the SDK to upload images and videos and metadata thereof to the platform from a mobile device. Further, the multimedia service platform may identify patterns from metadata extracted from images and videos. Further, embodiments presented herein can identify latent relationships between different categories, topics, or subjects (referred to generally as interests or user interests) from multimedia collections of multiple users. For example, if many users take pictures at golf courses also take pictures at an unrelated event (e.g., at a traveling museum exhibit) then the system can discover a relationship between these otherwise unrelated interests. Thereafter, advertising related to golfing products and services could be targeted to individuals who publish pictures of the travelling museum exhibit, regardless of any other known interest in golf.
[0023] In one embodiment, the multimedia service platform evaluates metadata corresponding to each image or video submitted to the platform against a knowledge graph. The knowledge graph provides a variety of information about events, places, dates, times, etc. that may be compared with the metadata of a given image. For example, the knowledge graph may include weather data, location data, event data, and online encyclopedia data. For instance, attributes associated with an event may include a name, location, start time, end time, price range, etc. The multimedia service platform correlates spatiotemporal metadata from a digital image with a specific event in the knowledge graph. That is, the knowledge graph is used to impute attributes related to events, places, dates, times, etc., to a given digital multimedia file based on the metadata provided with that file.
[0024] In one embodiment, the analysis tool represents attributes imputed to digital multimedia in a user-attribute matrix, where each row of the matrix represents a distinct user and each column represents an attribute from the knowledge graph that can be imputed to a digital multimedia file. The analysis tool may add columns to the user-attribute matrix as additional attributes are identified. The cells of a given row indicate how many times a given attribute has been imputed to a digital multimedia file published by a user corresponding to that row. Accordingly, when the analysis tool imputes an attribute to a digital multimedia file (based on the file metadata), a value for that attribute is incremented in the user-attribute matrix. Doing so allows the multimedia service platform to identify useful information about that user. For instance, the analysis tool may identify that a user often attends sporting events, movies, participates in a particular recreational event (e.g., skiing or golf), etc. In addition, the analysis tool may identify information about events that the user attends, such as whether the events are related to a given sports team, whether the events are related to flights from an airport, a range specifying how much the event may cost, etc.
[0025] In one embodiment, the multimedia service platform learns concepts based on co-occurring attributes identified in the user-attribute matrix. A concept is a collection of one or more identified attributes. The multimedia service platform may use machine learning techniques to learn concepts from the attributes of the user-attribute matrix. For example, machine learning techniques cluster or otherwise group group attributes based on co-occurrences. For instance, “travel,” “winter,” “Park City,” and “skiing” may frequently co-occur. As a result, the machine learning techniques may group these co-occurring attributes into a concept (e.g., a “skiing” concept). Further, the multimedia service platform may score an attribute to each respective concept. The multimedia service platform may associate attributes that satisfy specified criteria (e.g., the top five scores per concept, attributes exceeding a specified threshold, etc.) to a given concept.
[0026] Further, the analysis tool may generate an interest taxonomy based on the learned concepts. In one embodiment, an interest taxonomy is a hierarchical representation of user interests. For example, the interest taxonomy can identify general groups (e.g., sports, music, and travel) and sub-groups (e.g., basketball, rock music, and discount airlines) of interest identified from the concepts. The multimedia service platform may use the interest taxonomy to discover latent relationships between concepts. For example, the multimedia service platform may build a predictive learning model using the interest taxonomy.
[0027] In one embodiment, the multimedia service platform may use the interest taxonomy to infer interests of a given user. To do so, the multimedia service platform builds a learning model that determines membership scores of a user for a given concept. By training the learning model, the multimedia service platform can identify latent interests of the user based on the interest taxonomy of the user as a result. Further, the multimedia service platform may map product feeds of third parties to user interest taxonomies to identify products to recommend to a given user. Doing so allows third parties to target more meaningful recommendations to a given user.
[0028] Note, the following description relies on digital images captured by a user and metadata as a reference example of learning latent interests based on the metadata. However, one of skill in the art will recognize that the embodiments presented herein may be adapted to other digital multimedia that include time and location metadata, such as digital videos captured on a mobile device. Further, an analysis tool may extract metadata particular to a type of the multimedia, e.g., the length of a video, which can be used relative to the techniques described herein.
[0029] FIG. 1 illustrates an example computing environment 100 , according to one embodiment. As shown, the computing environment 100 includes mobile devices 105 , an extract, transform, and load (ETL) server 110 , an application server 115 , and a third party system 120 , connected to a network 125 (e.g., the Internet).
[0030] In one embodiment, the mobile devices 105 include a mobile application 106 which allows users to interact with a multimedia service platform (represented by the ETL server 110 and the application server 115 ). In one embodiment, the mobile application 106 is developed by a third-party enterprise (e.g., a retailer, social network provider, fitness tracker developer, etc.). The mobile application 106 may send images 108 and associated metadata to the multimedia service platform. In one embodiment, the mobile application 106 may access APIs exposed by a software development kit (SDK) distinct to the platform.
[0031] In another embodiment, the mobile application 106 may access a social media service (application service 116 ) provided by the service platform. The social media service allows users to capture, share, and comment on images 108 as a part of existing social networks (or in conjunction) with those social networks. For example, a user may publish images 108 captured using a camera on mobile device 105 to a specified social network. In turn, the application 106 retrieves metadata and images 108 and metadata to the multimedia service platform. The multimedia service platform uses the metadata to infer latent interests of the userbase as well as latent relationships between the interests.
[0032] The mobile application 106 extracts Exchangeable Image Format (EXIF) metadata from each image 108 . The mobile application 106 can also extract other metadata (e.g., PHAsset metadata in Apple iOS devices) describing additional information, such as GPS data. In addition, the mobile application 106 may perform extract, transform, and load (ETL) operations on the metadata to format the metadata for use by components of the multimedia service platform. For example, the mobile application 106 may determine additional information based on the metadata, such as whether a given image was taken during daytime or nighttime, whether the image was taken indoors or outdoors, whether the image is a “selfie,” etc. Further, the mobile application 106 also retrieves metadata describing application use. Such metadata includes activity by the user on the mobile application 106 , such as image views, tagging, etc. Further, as described below, the mobile application 106 provides functionality that allows a user to search through a collection of images by the additional metadata, e.g., searching a collection of images that are “selfies” and taken in the morning.
[0033] In one embodiment, the ETL server 110 includes an ETL application 112 . The ETL application 112 receives streams of image metadata 114 (e.g., the EXIF metadata, PHAsset metadata, and additional metadata) from mobile devices 105 . Further, the ETL application 112 cleans, stores, and indexes the image metadata 114 for use by the application server 115 . Once processed, the ETL application 112 may store the image metadata 114 in a data store, e.g., such as in a database or a Hadoop-based storage architecture (e.g., Hive), for access by the application server 115 .
[0034] In one embodiment, the application service 116 communicates with the mobile application 106 . The application server 115 may be a physical computing system or a virtual machine instance in a computing cloud. Although depicted as a single server, the application server 115 may comprise multiple servers configured as a cluster (e.g., via the Apache Spark framework, a Hadoop-based storage architecture). A clustered architecture allows the application servers 115 to process large amounts of images and image metadata sent from mobile applications 106 .
[0035] As shown, the application server 115 includes an analysis tool 117 , a knowledge graph 118 , and a user interest taxonomy 119 . As described below, the user interest taxonomy 119 represents interests inferred from image attributes identified from the knowledge graph 118 based on the image metadata 114 from image collections of multiple users.
[0036] In one embodiment, the knowledge graph 118 includes a collection of attributes which may be imputed to an image. Example attributes include time and location information, event information, genres, price ranges, weather, subject matter, and the like. The analysis tool 117 builds the knowledge graph 118 using weather data, location data, events data, encyclopedia data, and the like from a variety of data sources.
[0037] In one embodiment, the analysis tool 117 imputes attributes from the knowledge graph 118 to an image 108 based on the metadata 114 . That is, the analysis tool 117 may correlate time and location information in image metadata 114 to attributes in the knowledge graph 118 . For example, assume that a user captures an image 108 of a baseball game. Metadata 114 for that image 108 may include a GPS, a date, and a time when the image 108 was captured. The analysis tool 117 can correlate this information to attributes such as weather conditions at that time and location (e.g., “sunny”), an event name (e.g., “Dodgers Game”), teams playing at that game (e.g., “Dodgers” and “Cardinals”), etc. The analysis tool 117 associates the imputed attributes with the user who took the image. As noted, e.g., a row in a user attribute matrix may be updated to reflect the imputed attributes of each new image taken by that user. Further, the analysis tool 117 may perform machine learning techniques, such as latent Dirichlet analysis (LDA), to decompose the user-attribute matrix into sub-matrices. Doing so allows the analysis tool 117 to identify concepts, i.e., clusters of attributes. The analysis tool 117 may use the user interest taxonomy 119 to generate product recommendations. The analysis tool 117 may also use the interest taxonomy 119 identify one or more users that may be interested in a product or service. For example, the analysis tool 117 may extract information from a product feed 121 of a third party system 120 . In one embodiment, the product feed 121 is a listing of products or services of a third party, such as a retailer. The analysis tool 117 may identify, from the product feed 121 , one or more attributes describing each product. For example, a product of a shoe retailer may have attributes such as “shoe,” “running,” “menswear,” and so on. The analysis tool 117 can map the attributes of the product feed 121 with the interest taxonomy 119 . Doing so allows the analysis tool 117 to identify products and services from the feed 121 that align with interests in the interest taxonomy. In turn, third parties can target users who may be interested in the identified products and services.
[0038] FIG. 2 illustrates mobile application 106 , according to one embodiment. As shown, mobile application 106 includes a SDK component 200 with APIs configured to send image and metadata information to the multimedia service platform. The SDK component 200 further includes an extraction component 205 , a search and similarity component 210 , and a log component 215 . In one embodiment, the extraction component 205 extracts metadata (e.g., EXIF metadata, PHAsset metadata, and the like) from images captured using a mobile device 105 . The metadata may describe various aspects specific the image, such as whether the image is in color or black and white, whether the image is a “selfie,” and the like. Further, the extraction component 205 may perform ETL preprocessing operations on the metadata. For example, the extraction component 205 may format the metadata for the search and similarity component 210 and the log component 215 .
[0039] In one embodiment, the search and similarity component 210 infers additional metadata from an image based on the metadata (e.g., spatiotemporal metadata) retrieved by the extraction component 205 . Examples of additional metadata include whether a given image was captured at daytime or nighttime, whether the image was captured indoors or outdoors, whether the image was edited, weather conditions when the image was captured, etc. Further, the search and similarity component 210 generates a two-dimensional image feature map from a collection of images captured on a given mobile device 105 , where each row represents an image and columns represent metadata attributes. Cells of the map indicate whether an image has a particular attribute. The image feature map allows the search and similarity component 210 to provide search features to a user. For example, the mobile application 106 may search for images on a mobile device which have a given attribute, such as images taken during daytime or taken from a particular location. In turn, the search and similarity component 210 may evaluate the image map to identify images (or other multimedia) having the particular attribute.
[0040] In one embodiment, the log component 215 evaluates the image metadata. For example, the log component 215 records metadata sent to the ETL server 110 . Once received, the application 112 performs ETL operations, e.g., loading the metadata into a data store (such as a database). The metadata is accessible by the analysis tool 117 .
[0041] FIG. 3 further illustrates the analysis tool 117 , according to one embodiment. As shown, the analysis tool 117 includes an aggregation component 305 , a knowledge graph component 310 , a user interest taxonomy generation component 320 , and a user interest inference component 325 .
[0042] In one embodiment, the aggregation component 305 receives streams of image metadata corresponding to images captured by users of application 106 by users from the ETL server 110 . Once received, the aggregation component 305 organizes images and metadata by user. The metadata may include both raw image metadata (e.g., time and GPS information) and inferred metadata (e.g., daytime or nighttime image, indoor or outdoor image, “selfie” image, etc.). To organize metadata by user, the aggregation component 305 evaluates log data from the ETL server 110 to identify image metadata from different devices (and presumably different users) and metadata type (e.g., whether the metadata corresponds to image metadata or application usage data).
[0043] In one embodiment, the knowledge graph component 310 builds (and later maintains) the knowledge graph 118 using any suitable data source, such as local news and media websites, online event schedules for performance venues, calendars published by schools, government, or private enterprises, online schedules and ticket sales. The knowledge graph component 310 determines attributes related to each event to store in the knowledge graph 118 .
[0044] In one embodiment, to impute attributes from the knowledge graph 118 to a given image, the knowledge graph component 310 evaluates time and location metadata of the image against the knowledge graph 118 . The knowledge graph component 310 determines whether the image metadata matches a location and/or event in the knowledge graph. The information may be matched using a specified spatiotemporal range, e.g., within a time period of the event, within a set of GPS coordinate range, etc. In one embodiment, the component 310 may further match the information based on a similarity of metadata of other user photos that have been matched to that event.
[0045] In one embodiment, the taxonomy component 320 evaluates the user-attribute matrix to determine concepts associated with a given user. As stated, a concept is a cluster of related attributes. The interest taxonomy generation component 320 may perform machine learning techniques, such as Latent Dirichlet Analysis (LDA), Non-Negative Matrix Factorization (NNMF), Deep Learning algorithms, and the like, to decompose the user-attribute matrix into sub-matrices. The taxonomy component 320 evaluates the sub-matrices to identify latent concepts from co-occurring attributes.
[0046] Further, the taxonomy component 320 may determine a membership score distribution for each attribute over each concept. A membership score indicates a measure of strength that a given attribute correlates with a concept. The interest taxonomy generation component 320 may populate a concept-attribute matrix, where the rows represent concepts and columns represent attributes. Each cell value is the membership score of the respective attribute to the respective concept. The generation component 320 may perform further machine learning techniques (e.g., LDA, NNMF, Deep Learning, etc.) to identify relationships and hierarchies between each concepts.
[0047] In one embodiment, the interest inference component 325 builds a learning model of user interests based on the identified concepts. To do so, the interest inference component 325 may train multi-class classifiers for predicting an interest score. For example, the inference component 325 may use Logistic Regression, Boosting, or Support Vector Machine (SVM) classifiers for each concept to determine user association with one or more concepts. Doing so results in each user in the platform being assigned an interest score per concept. Further, doing so provides positive and negative membership examples used to train the learning model.
[0048] Once trained, the interest inference component 325 may predict user interests using the learning model. As the multimedia service platform receives image metadata from new users, the interest inference component 325 can assign the new users with membership scores for each concept based on the metadata and the learning model. A user having a high membership score in a given concept may indicate a high degree of interest for that concept.
[0049] FIG. 4 illustrates an example user interest taxonomy 400 , according to one embodiment. As shown, the taxonomy 400 is a hierarchical representation of user interests identified from image metadata, such as metadata describing time and location information of a given image. Each node in the taxonomy 400 represents a concept identified from one or more attributes. As stated, the interest taxonomy generation component 320 may perform machine learning (e.g., LDA) to identify hierarchies and relationships between concepts. The hierarchies and relationships may further be determined manually (e.g., by a subject matter expert).
[0050] The taxonomy 400 includes groups 410 and sub-groups 415 . Illustratively, the concepts depicted in groups 410 include generally broader concepts, such as sports, music, and travel. The sub-groups 415 include more specific concepts related to the groups 410 , such as basketball, rock, and airlines. Further, each sub-group 415 may have its own subgroup. For example, the baseball node may include sub-group nodes depicting team names. Note, FIG. 4 depicts a relatively small amount of concept nodes in the taxonomy 400 . In practice, the taxonomy 400 may include a greater amount of nodes (e.g., 1,000 concept nodes).
[0051] Each user in the multimedia service platform may be associated with one or more concepts in the interest taxonomy 400 . For a given user, the interest inference component 325 may determine a distribution of membership scores to each identified concept. The membership score may indicate a strength of correlation to a degree of interest that the user has for a given concept. For example, a high membership score in the football concept may indicate that a user has a high interest in football. Further, the interest inference component 325 may build a predictive learning model based on the membership score distribution. The interest inference component 325 can train the model using membership and non-membership of users to a given concept as positive and negative examples of concept membership. Thus, when the multimedia service platform receives new image data and metadata from a user, the interest inference component 325 may predict the user membership scores to each concept based on the image metadata. As a result, the interest inference component 325 can infer additional concepts to which new user belongs, even with a limited amount of image metadata. Such information may be useful to third party advertisers for targeted recommendations.
[0052] FIG. 5 illustrates a method 500 for determining a set of concepts based on image metadata, according to one embodiment. Method 500 begins at step 505 , where the aggregation component 305 segments images by users. Doing so allows the analysis tool 107 to evaluate collections of image metadata for each user individually.
[0053] At step 510 , the knowledge graph component 310 imputes attributes from the knowledge graph 118 onto the images based on the image metadata. To do so, the graph component 310 correlates time and location metadata of a given image to information provided in the knowledge graph, such as events, that coincide with the time and location metadata (with a degree of allowance). As a result, each image is associated with a set of attributes.
[0054] At step 515 , the knowledge graph component 310 builds a user-attribute matrix based on the imputed attributes to the images. The knowledge graph component 310 further imputes attributes associated with each image to the respective user. Each cell in the user-attribute matrix is an incremental value that represents a count of images in which the corresponding attribute is present.
[0055] At step 520 , the interest taxonomy generation component 320 decomposes the user-attribute matrix to identify concepts from the attributes. As stated, a concept may include one or more attributes. The interest taxonomy generation component 320 may evaluate the attributes using machine learning techniques to identify the concepts. Further, the interest taxonomy generation component 320 may generate an attribute-concept matrix, where the cell values represent membership scores of each attribute to a given concept. Attributes having a qualifying score may be associated with the concept.
[0056] FIG. 6 illustrates a method 600 for building a predictive model for inferring user interests, according to one embodiment. Method 600 begins at step 605 , where the interest inference component 325 determines, for each user, a membership score for each concept relative to other concepts. To do so, the interest inference component 325 may generate a user-attribute-concept matrix which is a dot product of the user-attribute matrix and the attribute concept matrix. Cell values of the user-attribute-concept matrix represent membership scores of a given user to each concept.
[0057] At step 610 , the interest inference component 325 assigns each user to one or more concepts based on the score. The interest inference component 325 may assign the user to a concept based on the concept in which the user has the highest membership score. Alternatively, the interest inference component 325 may assign the user to a concept based on threshold scores. In particular, if the membership score for a concept exceeds a threshold, the interest inference component 325 assigns the user to the concept.
[0058] At step 615 , the interest inference component 325 trains multiple one-versus-all predictive models for inferring user interests. The interest inference component 325 may build Support Vector Machine (SVM) classifiers for each concept. The SVM classifiers evaluate a given concept relative to other identified concepts. To train one-versus-all predictive models, the interest inference component 325 may use user membership to concepts as positive and negative examples of membership.
[0059] FIG. 7 illustrates a method 700 for inferring user interests based on a predictive model, according to one embodiment. Method 700 may occur any time a new user sends images to the multimedia service platform through the mobile application 106 . As stated, the ETL server 110 formats the image and metadata for processing by the analysis tool 117 . Method 700 begins at step 705 , where the user aggregation component 305 receives one or more images captured by the new user. The user aggregation component 305 segments the images by user ID.
[0060] At step 710 , the knowledge graph component 310 imputes attributes from the knowledge graph 118 to each image based on image metadata. To do so, the knowledge graph component 310 correlates time and location metadata of a given image to information provided in the knowledge graph, such as events, that coincide with the time and location metadata (with a degree of allowance). As a result, each image is associated with a set of attributes.
[0061] At step 715 , the interest inference component 325 predicts a concept score distribution for the user based on the predictive models. The interest inference component 710 may evaluate the attributes identified in the knowledge graph imputation to determine concept scores for each attribute based on the predictive models. The interest inference component 325 may perform a dot product of the user row in the user-attribute matrix to the concept-attribute matrix to determine user membership scores to each concept. The interest inference component may then assign the new user to one or more concepts based on the scores.
[0062] FIG. 8 illustrates an application server computing system 800 configured to impute knowledge graph attributes onto image metadata, according to one embodiment. As shown, the computing system 800 includes, without limitation, a central processing unit (CPU) 805 , a network interface 815 , a memory 820 , and storage 830 , each connected to a bus 817 . The computing system 800 may also include an I/O device interface 810 connecting I/O devices 812 (e.g., keyboard, mouse, and display devices) to the computing system 800 . Further, in context of this disclosure, the computing elements shown in computing system 800 may correspond to a physical computing system (e.g., a system in a data center) or may be a virtual computing instance executing within a computing cloud.
[0063] The CPU 805 retrieves and executes programming instructions stored in the memory 820 as well as stores and retrieves application data residing in the memory 820 . The interconnect 817 is used to transmit programming instructions and application data between the CPU 805 , I/O devices interface 810 , storage 78 representative of a single CPU, multiple CPUs, a single CPU having multiple processing cores, and the like. And the memory 820 is generally included to be representative of a random access memory. The storage 830 may be a disk drive storage device. Although shown as a single unit, the storage 830 may be a combination of fixed and/or removable storage devices, such as fixed disc drives, removable memory cards, or optical storage, network attached storage (NAS), or a storage area-network (SAN).
[0064] Illustratively, the memory 820 includes an application service 822 and an analysis tool 824 . The storage 830 includes a knowledge graph 834 , and an interest taxonomy 836 . The application service 822 provides access to various services of the multimedia service platform to mobile devices. The analysis tool 824 generates a user interest taxonomy 836 based on metadata of images taken by users.
[0065] In one embodiment, the analysis tool 824 builds the knowledge graph 834 from external data sources. To do so, the analysis tool 824 performs NLP techniques on the raw text obtained from the data sources to identify relevant terms related to events, moments, weather, etc.
[0066] In one embodiment, the analysis tool 824 may impute information from the knowledge graph 834 images submitted to the multimedia service platform. In addition, the analysis tool 824 generates a user interest taxonomy 836 of concepts inferred from the attributes. To do so, the analysis tool 824 may perform machine learning techniques (e.g., LDA, pLSA, NNMF, etc.) to learn concepts based on co-occurring attributes. In addition, the analysis tool 824 may determine a membership score for each attribute to each identified concept. The analysis tool 824 may associate attributes to a given concept based on the membership score. Further, the analysis tool 824 may identify hierarchical relationships between the concepts through machine learning.
[0067] In one embodiment, the analysis tool 824 performs further machine learning techniques to assign users to each identified concept. In particular, the analysis tool 824 may determine membership scores for each concept for a given user. The user may be associated with a concept in which the membership score is the highest. Alternatively, the user may be associated with multiple concepts based on the top membership scores (e.g., top five scores, top ten scores, etc.). The analysis tool 824 may train SVM classifiers for each concept to build a predictive model that can be used to predict membership scores for new users.
[0068] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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Techniques disclosed herein describe inferring user interests based on metadata of a plurality of multimedia objects captured by a plurality of users. An analysis tool receives, for each of the users, metadata describing each multimedia object in the plurality of objects associated with that user. Each multimedia object includes one or more attributes imputed to that object based on the metadata. The analysis tool identifies one or more concepts from the one or more attributes. Each concept includes at least a first attribute that co-occurs with a second attribute imputed to a first multimedia object. The analysis tool associates a first one of the plurality of users with at least one of the concepts based on the attributes imputed to multimedia objects associated with the first one of the plurality of users
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This application is based on provisional application No. 60/087,642 filed Jun. 2, 1998.
BACKGROUND OF THE INVENTION
Immunophilins are cytosolic proteins endowed with peptidylprolyl-cis-trans isomerase (PPIase or rotamase) activity. This family of proteins behave as chaperone molecules causing cis-trans isomerization of specific prolyl amide bonds that could be a rate limiting step in the correct folding of certain proteins. They are also involved in many cellular signal transduction pathways as partners in multiprotein complexes for which binding in the rotamase active site, but not rotamase activity per se, appears to be important (Ruhlmann, et al., Immunobiol., 198, pp. 192-206 (1998)). Immunosuppressive drugs such as FK506, rapamycin and cyclosporin A bind to specific groups of immunophilins. FK506 and rapamycin bind to the so-called FK506-binding proteins (e.g. FKBP-12, -25, -52), whereas the cyclophilins bind to cyclosporin A. It has been shown that binding to the 12kD immunophilin FKBP12 is necessary for FK506 to elicit its immunosuppressive activity. Subsequently, it was also found that FK506 has two binding domains: one that binds to FKBP12 and the other (the effector domain) for the complex of FK506 and FKBP12 that binds to the serine/threonine phosphatase, calcineurin. This complexation inhibits calcineurin and prevents the proliferation of T-lymphocytes, causing immunosuppression. Rapamycin has an effector domain of a different structure, and its complex with FKBP12 binds to a different target protein that, however, has the same effect of inhibiting T-lymphocyte proliferation. For a review, see S. L. Schreiber, et al., Tetrahedron, 48, pp. 2545-2558 (1992).
While FK506 exhibits immunosuppressive effects, analogs lacking the calcineurin binding effector domain are devoid of immunosuppressive activity. Many small molecules that contain the essential elements of the FKBP12 binding domain of FK506 but lack the calcineurin binding domain were found to retain high affinity binding to FKBP12, and behave as rotamase inhibitors (D. S. Yamshita, et al., Bioorg. Med. Chem. Lett., 4, pp. 325-328 (1994); D. M. Armistead, et al., Acta Cryst. D, 51, pp. 522-528 (1995)).
FK506 has been shown to possess neurotrophic properties in vitro and in vivo (W. E. Lyons, et al., Proc. Natl. Acad. Sci USA, 91, pp. 3191-3195 (1994); B. G. Gold, et al., J. Neurosci., 15, pp. 7509-7516 (1995)). However, its immunosuppressive properties as well as other serious side effects are drawbacks to its use as a neuroregenerative agent. Recently, in vitro studies in PC12 cells, SY5Y cells, and chick sensory dorsal root ganglion explant cultures have shown that small molecule, nonimmunosuppressive FKBP12 rotamase inhibitors also promote neurite outgrowth, and a number of these compounds have shown utility in reversal of CNS lesioning and nerve crush in animal models (G. S. Hamilton, et al., Curr. Pharm. Design, 3, pp. 405-428 (1997); B. G. Gold, et al., Exp. Neurol., 147, pp. 269-278 (1997)). Thus, while the calceineurin binding domain of FK506 is necessary for immunosuppressive activity, it is not required for neurotrophic activity.
A 10-50 fold elevated expression of immunophilins in the central nervous system in comparison with the immune system is well documented (S. H. Snyder, et al., Nature Med., 1, pp. 32-37 (1995)). Recently, augmented expression of FKBP12 m-RNA following facial nerve crush and sciatic nerve lesions was established in facial and lumbar motor neurons. The observed augmentation paralleled the enhanced expression of growth associated protein GAP43 mRNA (B. G. Gold, et al., Neurosci. Lett., 241, pp. 25-28 (1998)). These observations make FKBP12 an attractive target for developing nonimmunosuppressive rotamase inhibitors which promote neurite outgrowth. Such compounds are potential therapeutics to reverse neuronal damage caused by neurodegenerative disease or physical trauma.
There have been disclosures of related compounds for overcoming multidrug resistance (MDR) or as immunosuppressants such as:
WO 94/07858 published Apr. 14, 1994
WO 92/19593 published Nov. 12, 1992
U.S. Pat. No. 5,622,970 granted Apr. 22, 1997
U.S. Pat. No. 5,330,993 granted Jul. 19, 1994
U.S. Pat. No. 5,192,773 granted Mar. 9, 1993
U.S. Pat. No. 5,516,797 granted May 14, 1996
WO 92/21313 published Dec. 10, 1992
European Application 564924 published Oct. 13, 1993
European Application 405994 published Jan. 2, 1991
Other prior art disclosing related compounds having neurotrophic activity are:
WO 96/40140 published Dec. 19, 1996
WO 96/40633 published Dec. 19, 1996
WO 97/16190 published May 9, 1997
WO 96/41609 published Dec. 27, 1997
U.S. Pat. No. 5,696,135 granted Dec. 9, 1997
WO 97/36869 published Oct. 9, 1997
U.S. Pat. No. 5,721,256 granted Feb. 24, 1998
U.S. Pat. No. 5,654,332 granted Aug. 5, 1997
WO 98/13343 published Apr. 2, 1998
WO 98/13355 published Apr. 2, 1998
Since there are relatively few FKBP12-binding compounds that are known to stimulate neurite growth, there remains a great need for additional neurotrophic, FKBP12-binding compounds.
SUMMARY AND OF THE INVENTION
Surprisingly, applicant has solved the aforementioned problem. The present invention relates to novel α,α-difluoro substituted acetamide compounds and pharmaceutical compositions thereof that possess neurotrophic properties.
DETAILED DESCRIPTION OF THE INVENTION
According to one embodiment, the present invention provides:
A compound with affinity for an FK506 binding protein having the formula (I): ##STR1## and pharmaceutically acceptable salts thereof: wherein W is CH 2 , O, NH, or N--(C 1 -C 4 )-alkyl;
wherein J is hydrogen, (C 1 -C 4 )-alkyl or benzyl;
wherein K is (C 1 -C 4 )-straight or branched alkyl, benzyl or cyclohexylmethyl, or wherein J and K may be taken together to form a 5-7 membered heterocyclic ring which may contain a heteroatom selected from the group consisting of O, S, SO, and SO 2 ;
wherein the stereochemistry at carbon position 1 is R or S;
wherein Z is Q or --(CH 2 ) m --C(H)Q'A;
wherein m is 0-3;
wherein Q is hydrogen, CHL-Ar, (C 1 -C 6 )-straight or branched alkyl, (C 2 -C 6 )-straight or branched alkenyl, (C 5 -C 7 )-cycloalkyl, (C 5 -C 7 )-cycloalkenyl, Ar substituted (C 1 -C 6 )-alkyl, (C 2 -C 6 )-alkenyl or ##STR2## wherein L and G are independently hydrogen, (C 1 -C 6 )-straight or branched alkyl, (C 2 -C 6 )-straight or branched alkenyl;
wherein T is Ar or substituted cyclohexyl with substituents at positions 3 and 4 which are independently selected from the group consisting of hydrogen, hydroxyl, O--(C 1 -C 4 )-alkyl or O--(C 2 -C 4 )-alkenyl and carbonyl;
wherein D is (C 1 -C 6 )-straight or branched alkyl, (C 2 -C 6 )-straight or branched alkenyl, (C 5 -C 7 )-cycloalkyl or (C 5 -C 7 )-cycloalkenyl substituted with (C 1 -C 4 )-straight or branched alkyl or (C 2 -C 4 )-straight or branched alkenyl, O--(C 1 -C 4 )-straight or branched alkyl, O--(C 2 -C 4 )-straight or branched alkenyl, 2-indolyl, 3-indolyl, [(C 1 -C 4 )-alkyl or (C 2 -C 4 )-alkenyl]-Ar or Ar;
wherein Ar is a carbocyclic aromatic group selected from the group consisiting of phenyl, 1-naphthyl, 2-naphthyl, indenyl, azulenyl, fluorenyl, and anthracenyl; or a heterocyclic aromatic group selected from the group consisting of 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, 1,2,3-oxadiazolyl, 1,2,3-triazolyl, 1,3,4-thiadiazolyl, pyridazinyl, pyrimidinyl, pyrazinyl, 1,3,5-triazinyl, 1,3,5-trithianyl, indolizinyl, indolyl, isoindolyl, 3H-indolyl, indolinyl, benzo[b]furanyl, benzo[b]thiophenyl, 1H-indazolyl, benzimidazolyl, benzthiazolyl, purinyl, 4H-quinolizinyl, quinolinyl, isoquinolinyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 1,8-naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, and phenoxazinyl;
wherein Ar may contain one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, hydroxymethyl, nitro, trifluoromethyl, trifluoromethoxy, (C 1 -C 6 )-straight or branched alkyl, (C 2 -C 6 )-straight or branched alkenyl, O--[(C 1 -C 4 )-straight or branched alkyl], O-benzyl, O-phenyl, 1,2-methylenedioxy, amino, carboxyl, N-[(C 1 -C 5 )-straight or branched alkyl or (C 2 -C 5 )-straight or branched alkenyl] carboxamides, N,N-di-[(C 1 -C 5 )-straight or branched alkyl or (C 2 -C 5 )-straight or branched alkenyl] carboxamides, N-morpholinecarboxamide, N-benzylcarboxamide, N-thiomorpholinocarboxamide, N-picolinoylcarboxamide, O--X, CH 2 -(CH 2 ) p --X, O--(CH 2 ) p --X, (CH 2 ) p --O--X, and CH═CH--X;
wherein X is 4-methoxyphenyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, pyrazyl, quinolyl, 3,5-dimethylisoxazoyl, isoxazoyl, 2-methylthiazoyl, thiazoyl, 2-thienyl, 3-thienyl, or pyrimidyl; wherein p is 0-2;
wherein Q' and A are independently hydrogen, Ar, (C 1 -C 10 )-straight or branched alkyl, (C 2 -C 10 )-straight or branched alkenyl or alkynyl, (C 5 -C 7 )cycloalkyl substituted-straight (C 1 -C 6 )-straight or branched alkyl, (C 2 -C 6 )-straight or branched alkenyl or alkynyl, (C 5 -C 7 )-cycloalkenyl substituted (C 1 -C 6 )-straight or branched alkyl, (C 2 -C 6 )-straight or branched alkenyl or alkynyl, or Ar substituted (C 1 -C 6 )-straight or branched alkyl, (C 2 -C 6 )-straight or branched alkenyl or alkynyl wherein, in each case, any one of the CH 2 groups of said alkyl, alkenyl or alkynyl chains may be optionally replaced by a heteroatom selected from the group consisting of O, S, SO, SO 2 and NR, wherein R is selected from the group consisting of hydrogen, (C 1 -C 4 )-straight or branched alkyl, (C 2 -C 4 )-straight or branched alkenyl or alkynyl, and (C 1 -C 4 )-bridging alkyl wherein a bridge is formed between the nitrogen and a carbon atom of said heteroatom-containing chain to form a ring, and wherein said ring is optionally fused to an Ar group; or ##STR3## wherein G' is hydrogen, (C 1 -C 6 )-straight or branched alkyl or (C 2 -C 6 )-straight or branched alkenyl or alkynyl.
Another embodiment of this invention are compounds of formula I wherein Z is --(CH 2 ) m --C(H)Q'A.
A preferred embodiment are compounds of formula I wherein J and K are taken together to form a piperidine ring; the stereochemistry at carbon 1 is S; W is oxygen; m is 0; D is 3,4,5-trimethoxyphenyl; Q' is 3-phenylpropyl; and A is 3-(3-pyridyl)propyl.
Another preferred embodiment are compounds of formula I wherein J and K are taken together to form a pyrrolidine ring; the stereochemistry at carbon 1 is S; W is oxygen; m is 0; D is 3,4,5-trimethoxyphenyl; Q' is 3-phenylpropyl; and A is 3-(3-pyridyl)propyl.
Another preferred embodiment are compounds of formula I wherein J and K are taken together to form a piperidine ring; the stereochemistry at carbon 1 is S; W is oxygen; m is 0; D is 3,4,5-trimethoxyphenyl; Q' is phenyl; and A is 2-phenylethyl.
Another preferred embodiment are compounds of formula I wherein J and K are taken together to form a pyrrolidine ring; the stereochemistry at carbon 1 is S; W is oxygen; m is 0; D is 3,4,5-trimethoxyphenyl; Q' is phenyl; and A is 2-phenylethyl.
Another preferred embodiment are compounds of formula I wherein J and K are taken together to form a piperidine ring; the stereochemistry at carbon 1 is S; W is oxygen; m is 0; D is 3,4,5-trimethoxyphenyl; and Q' and A are both (C 1 -C 4 )-straight chain alkyls substituted at the terminal end with a (C 5 -C 7 )-cycloalkyl, (C 5 -C 7 )-cycloalkenyl or Ar.
Another preferred embodiment are compounds of formula I wherein J and K are taken together to form a pyrrolidine ring; the stereochemistry at carbon 1 is S; W is oxygen; m is 0; D is 3,4,5-trimethoxyphenyl; and Q' and A are both (C 1 -C 4 )-straight chain alkyls substituted at the terminal end with a (C 5 -C 7 )-cycloalkyl, (C 5 -C 7 )-cycloalkenyl or Ar.
Another preferred embodiment are compounds of formula I wherein J and K are taken together to form a piperidine ring; the stereochemistry at carbon 1 is S; W is oxygen; m is 0; D is 3,4,5-trimethoxyphenyl; Q' is a (C 5 -C 7 )-cycloalkyl, (C 5 -C 7 )-cycloalkenyl or Ar; and A is a (C 1 -C 4 )-straight chain alkyl substituted at the terminal end with a (C 5 -C 7 )-cycloalkyl, (C 5 -C 7 )-cycloalkenyl or Ar.
Another preferred embodiment are compounds of formula I wherein J and K are taken together to form a pyrrolidine ring; the stereochemistry at carbon 1 is S; W is oxygen; m is 0; D is 3,4,5-trimethoxyphenyl; Q' is a (C 5 -C 7 )-cycloalkyl, (C 5 -C 7 )-cycloalkenyl or Ar; and A is a (C 1 -C 4 )-straight chain alkyl substituted at the terminal end with a (C 5 -C 7 )-cycloalkyl, (C 5 -C 7 )-cycloalkenyl or Ar.
Another aspect of the present invention provides for a pharmaceutical composition which comprises as an active ingredient an amount of a compound of formula I, or a pharmaceutically acceptable salt thereof, effective for stimulating neurite growth in nerve cells, and one or more pharmaceutically acceptable carriers, excipients or diluents thereof.
Another aspect of the present invention provides for a method for stimulating neurite growth in nerve cells comprising the step of contacting said nerve cells with a composition comprising a neurotrophic amount of a compound of formula I with affinity for an FK-506 binding protein.
Another aspect of the present invention provides for a method for stimulating neurite growth in nerve cells comprising the step of contacting said nerve cells with a composition comprising a neurotrophic amount of a compound of formula I with affinity for FKBP12.
GENERAL SUMMARY OF COMPOUND PREPARATION
The syntheses of the examples described in Table 1 was carried out using one of the methods described below that are commonly employed in peptide chemistry (see M. Bodanszky and A. Bodanszky, "The Practice of Peptide Synthesis," Springer-Verlag, Berlin (1984)):
A) An acylation reaction involving p-methylthiophenolic ester of α,α-difluoro-3,4,5-trimethoxyphenylacetic acid with appropriate prolyl or pipecolate ester in dimethylformamide (DMF) in the presence of diisopropylethylamine. ##STR4## B) Acylation of proline or pipecolic acid with the p-methylthiophenolic ester of α,α-difluoro-3,4,5-trimethoxyphenylacetic acid, followed by esterification of the resulting acid with the appropriate alcohol using a water soluble carbodiimide coupling reagent in acetonitrile. ##STR5## C) Schotten-Baumann reaction of in situ generated α,α-difluoro-3,4,5-trimethoxyphenylacetyl chloride with the appropriate prolyl or pipecolate ester. ##STR6## D) Peptide coupling using carbodiimide or a mixed anhydride approach were also used in some cases. ##STR7##
The α,α-difluoro-3,4,5-trimethoxyphenylacetic acid or its p-methylthiophenolic ester required for the above three approaches were synthesized by fluorination of the parent keto compound with diethylaminosulfurtrifluoride. In the case of the fluorination of 3,4,5-trimethoxyphenyl-α-oxoacetic acid, the corresponding N,N-diethylamide was also obtained. This N,N-diethylamide could be easily converted to the desired acid by alkaline hydrolysis. ##STR8##
The α,α-difluoro-3,4,5-trimethoxyphenylacetic acid was converted to the corresponding acid chloride using oxalyl chloride and catalytic dimethylformamide in methylene chloride. ##STR9##
PREPARATION OF REAGENTS
General
1 H NMR spectra in deuterated chloroform were run on a Bruker AC-300 or a Varian Gemini 300 spectrometer and chemical shifts were reported in ppm (δ) with reference to tetramethylsilane. All evaporations were carried out on a rotary evaporator under reduced pressure. Magnesium sulfate was used for drying the organic layer after extractive work up. LC-MS analysis were carried out on a Shimadzu instrument using either of the following two systems: System 1 consists of a PHX-LUNA C18 column (4.6×30 mm) employing a 4 min linear gradient of 20% to 100% solvent B:A (solvent A: 10% methanol, 90% water, 0.1% trifluoroacetic acid; solvent B: 90% methanol, 10% water, 0.1% trifluoroacetic acid) with the UV detector set at 220 nm. System 2 consists of a YMC C18 column (4.6×50 mm) employing a 4 or 8 min linear gradient of 0% to 100% solvent B:A with other conditions as described above for system 1. The water soluble carbodiimides used were either the hydrochloride salt or the methiodide of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC). Abbreviations used were in accordance with the guidelines provided by the American Chemical Society for their publications.
p-(Methylthio)phenolic ester of 3,4,5-trimethoxyphenyl-α-oxoacetic acid
To a stirred solution of 3,4,5-trimethoxyphenyl-α-oxoacetic acid (12.0 g, 49.9 mmol) in anhydrous acetonitrile (150 mL) at ambient temperature was added 4-(methylthio)-phenol (8.40 g, 59.9 mmol), dicyclohexylcarbodiimide (DCC) (15.4 g, 74.9 mmol) and 4-dimethylaminopyridine (0.428 g, 3.50 mmol) under nitrogen. The reaction mixture was stirred for 8 h, then cooled to 0° C. in an ice bath and 1M solution of oxalic acid in acetonitrile was added. The precipitated dicyclohexylurea was removed by filtration. The filtrate was diluted with ethyl acetate (400 mL) and the organic layer was washed with water (3×200 mL), brine (200 mL) and dried. The solvent was evaporated to give a pale yellow solid which was recrystallized from 2-propanol to give the pure ester (11.0 g, 61% yield). MS: M+H =363. 1 H-NMR: 7.41 (s, 2H), 7.35 (d, J =8.7 Hz, H 2 & H 6 , 2H), 7.21 (d, J=8.7 Hz, H 3 & H 5 , 2H), 3.99 (s, 3H), 3.94 (s, 6H), 2.52 (s, 3H).
p-(Methylthio)phenolic ester of α,α-difluoro-3,4,5-trimethoxyphenylacetic acid
To a stirred solution of the p-(methylthio)phenolic ester of 3,4,5-trimethoxyphenyl-α-oxoacetic acid (1.00 g, 2.76 mmol) in anhydrous methylene chloride (10 mL) at room temperature was added diethylaminosulfurtrifluoride (DAST) (4.44 g, 27.6 mmol) under nitrogen. The reaction mixture was stirred overnight. It was then cooled in an ice bath and excess DAST was quenched by dropwise addition of water. Ethyl acetate (150 mL) was then added and the organic layer was washed repeatedly with water until the pH of the aqueous layer was neutral. The organic layer was then washed with brine (50 mL), dried, and the solvent evaporated to afford the title compound (0.961 g, 2.50 mmol, 91%) as a brown solid. 1 H-NMR: 7.27 (d, J=8.7 Hz, H 2 & H 6 , 2H), 7.04 (d, J=8.8 Hz, H 3 & H 5 , 2H), 6.92 (s, 2H), 3.92 (s, 6H), 3.91 (s, 3H), 2.48 (s, 3H).
α,α-Difluoro-3,4,5-trimethoxyphenylacetic acid
To a stirred solution of 3,4,5-trimethoxyphenyl-α-oxoacetic acid (3.81 g, 15.8 mmol) in anhydrous methylene chloride (30 mL) at room temperature was added DAST (20.4 g, 127 mmol) under nitrogen and the mixture was stirred overnight. The mixture was then cooled in an ice bath and excess DAST was quenched by dropwise addition of water. Ethyl acetate (300 mL) was added and the organic layer was washed with saturated aqueous sodium bicarbonate (2×100 mL) followed by water (100 mL). The residue obtained after drying and evaporation was purified by silica gel chromatography, eluting with hexane/ethyl acetate (9:1 to 7:3), to give the N,N-diethylamide derivative (2.10 g, 6.62 mmol, 42%) as a pale yellow solid. 1 H-NMR: 6.77 (s, 2H), 3.88 (s, 9H), 3.45 (q, J=7.0 Hz, 2H), 3.25 (q, J=7.0 Hz, 2H), 1.20 (t, J=7.0 Hz, 3H), 1.10 (t, J=6.9 Hz, 3H). Bicarbonate washing after acidification and extractive work up with ethylacetate gave the crude title compound. Purification by reversed phase column (C18) chromatograhy eluting with water/methanol/trifluoroacetic acid (69.9:30:0.1) gave the pure difluoro acid (0.616 g, 2.34 mmol, 15%) as a white solid. 1 H-NMR: 6.85 (s, 2H), 3.90 (s, 6H), 3.89 (s, 3H). Anal. C: 50.59, H: 4.72, F: 14.24 (found), C: 50.39, H: 4.61, F: 14.49 (calcd). The N,N-diethylamide (2.00 g, 6.30 mmol) obtained above was hydrolyzed to the title acid by heating a solution in ethanol (5 mL) with 10% sodium hydroxide (13 mL) at reflux for 4 h. Acidification followed by extractive work up with ethyl acetate gave the crude acid which was purified as described above to give 1.51 g of the title compound as a white solid.
α,α-Difluoro-3,4,5-trimethoxyphenylacetylchloride
A stirred solution of α,α-difluoro-3,4,5-trimethoxyphenylacetic acid (1.50 g, 6.63 mmol) in anhydrous methylene chloride (20 mL) was treated with oxalyl chloride (2.52 g, 19.8 mmol) and 1 drop of dimethylformamide. After vigorous effervescence ceased, the reaction mixture was stirred for 3 h. The solvents were evaporated and traces of oxalyl chloride were removed by repeated evaporation with anhydrous methylene chloride to give the acid chloride (1.61 g, 99% yield) as a dark yellow solid.
EXAMPLE 1 ##STR10##
A suspension of N-Boc-L-proline (6.04 g, 28.0 mmol), 3-phenylpropanol (4.58 g, 33.6 mmol), DCC (8.68 g, 42.0 mmol), and 4-dimethylaminopyridine (0.210 g, 1.72 mmol) in anhydrous ether (60 mL) was stirred under nitrogen for 8 h. Water (200 mL) was added and the mixture was extracted with ethyl acetate (3×200 mL). The organic layer was separated and washed with water (2×100 mL), brine (2×100 mL), dried and evaporated. Purification of the residue by silica gel chromatography eluting with hexane/ethyl acetate (7:3 to 7:3) gave the pure phenylpropyl ester (7.62 g, 81%) as a colorless oil. MS: M+H=334. 1 H NMR: 7.26 (m, 2H), 7.17 (m, 3H), 4.31 & 4.21 (dd, J=8.1, 3.2 Hz, 1H), 4.09 (m, 2H), 3.59-3.32 (m, 2H), 2.64 (t, J=8.9 Hz, 2H), 2.19 (m, 1H), 1.91 (m, 5H), 1.42 (s, 4H), 1.39 (s, 6H). A portion of this material (0.393 g, 1.18 mmol), in methylene chloride (8 mL) was treated with trifluoroacetic acid (0.13 mL). After 1 h volatiles were evaporated and a solution of the resulting trifluoroacetate salt in dimethylformamide (12 mL) was combined with p-methylthiophenolate ester of 3,4,5-trimethoxy-α,α-difluorophenyl acetic acid (0.428 g, 1.18 mmol) and diisopropylethylamine (0.152 g, 1.18 mmol). The solution was stirred for 18 h, and then diluted with ethyl acetate (100 mL), washed with water (50 mL), and dried. The solvent was removed by evaporation. The residue was purified by silica gel chromatography, eluting with hexane/ethyl acetate (9:1 to 4:1) to give the product (0.360 g, 0.755 mmol, 64%) as a brown oil. (M+H)=478. 1 H NMR: 7.25 (m, 2H), 7.17 (m, 3H), 6.87 (s, 2H), 4.57 (m, 1H), 4.10 (m, 2H), 3.87 (s, 6H), 3.85 (s, 3H), 3.57 (m, 2H), 2.68 (t, J=7.5 Hz, 2H), 2.16 (m, 1H), 1.96 (m, 5H).
EXAMPLE 2 ##STR11##
Esterification of N-Boc-L-proline (1.01 g, 4.60 mmol) with 3-(3'-pyridyl)propan-1-ol (0.772 g, 5.60 mmol) was carried out using DCC (1.45 g, 7.00 mmol) and 4-dimethylaminopyridine (0.102 g, 0.834 mmol) in anhydrous ether (25 mL). Work up was carried out as described above for example 1. Purification by silica gel chromatography, eluting with hexane/ethyl acetate (7:3 to 3:7) gave the N-Boc-prolylester of 3-(3'-pyridyl)propan-1-ol (1.34 g, 4.00 mmol, 87%) as a colorless oil. MS: M+H=335. 1 H-NMR: 8.42 (m, 2H), 7.50 (m, 1H), 7.20 (m, 1H), 4.36 & 4.22 (dd, J=8.0, 3.0 Hz, 1H, rotamers), 4.17 (m, 2H), 3.49 (m, 2H), 2.70 (t, J=10.0 Hz, 2H), 2.20 (m, 1H), 1.91 (m, 5H), 1.43 (s, 4.5H), 1.39 (s, 4.5H). The N-Boc-prolylester of 3-(3'-pyridyl)propan-1-ol (0.271 g, 0.811 mmol), was deprotected and coupled with the p-methylthiophenolate ester of 3,4,5-trimethoxy-α,α-difluorophenyl acetic acid (0.312 g, 0.811 mmol), diisopropylethylamine (0.104 g, 0.811 mmol) in dimethylformamide (20 mL) as described in example 1. The crude product was partitioned between ethyl acetate (200 mL) and 1M hydrochloric acid (2×25 mL). The aqueous layer was basified with sodium bicarbonate and extracted with ethyl acetate (3×100 mL). The solution was evaporated after washing with water and drying. Purification of the residue by silica gel chromatography, eluting with chloroform/methanol (99.3:0.7) provided the title compound (0.331 g, 0.692 mmol, 85%) as pale brown oil. M+H=479. 1 H-NMR: 8.38 (m, 2H), 7.45 (m, 1H), 7.18 (m, 1H), 6.83 (s, 2H), 4.57 & 4.53 (dd, J=8.5, 3.2 Hz, 1H, rotamers), 4.17 (m, 1H), 4.06 (m, 1H), 3.83 (s, 6H), 3.81 (s, 3H), 3.53 (m, 2H), 2.66 (t, J=7.6 Hz, 2H), 2.12 (m, 1H), 1.88 (m, 5H).
EXAMPLE 3 ##STR12##
The coupling of L-proline with the p-(methylthio)phenolic ester of (α,α-difluoro-3,4,5-trimethoxyphenylacetic acid was carried out as described above for example 2. The trimethoxydifluorophenylacetamidoproline derivative was obtained in 89% yield after purification by silica gel chromatography, eluting with methylene chloride/ethyl acetate/acetic acid (70:27.5:2.5). M+H=360. 1 H-NMR: 8.51 (br, OH), 6.88 (s, 2H), 4.65 (m, 1H), 3.89 (s, 9H), 3.55 (m, 2H), 2.20 (m, 2H), 1.98 (m, 2H). LC-MS: System 1, t R =5.2 min. Water soluble carbodiimide (EDC hydrochloride, 0.318 g, 1.66 mmol) mediated esterification of the intermediate acid (0.400 g, 1.11 mmol) with 1-phenyl-7-(3'-pyridyl)-heptan-4-ol (0.358 g, 1.33 mmol), in the presence of a catalytic amount of dimethylaminopyridine (0.101 g, 0.830 mmol) in acetonitrile (25 mL) gave, after extractive work up with ethyl acetate and water, the crude product. Purification by silica gel chromatography gave the title compound (0.425 g, 0.695 mmol, 63%) as a yellow oil. MS: M+H=611. 1 H-NMR: 8.36 (m, 2H), 7.58-7.39 (m, 1H), 7.22-7.07 (m, 6H), 6.80 (d, J=3.1 Hz, 2H), 4.88 (m, 1H), 4.48 (m, 1H), 3.79 (m, 9H), 3.44 (m, 2H), 2.54 (m, 4H), 2.08 (m, 1H), 1.83 (m, 2H), 1.52 (m, 9H). LC-MS: System 2 (8 min gradient), t R for the diastereomers was 6.9 and 7.2 min.
EXAMPLE 4 ##STR13##
N-Boc-L-pipecolic acid (0.280 g, 1.22 mmol) was esterified with 1-phenyl-7-(3'-pyridyl)-heptan-4-ol (0.394 g, 1.46 mmol) employing EDC hydrochloride (0.350 g, 1.83 mmol) and 4-dimethylaminopyridine (0.081 g, 0.663 mmol) in acetonitrile (25 mL). Purification by silica gel chromatography, eluting with chloroform/methanol (100:0 to 99:1), gave the pure 1-phenyl-7-(3'-pyridyl)-heptan-4-ol ester of N-Boc-pipecolic acid in 85% yield (0.498 g) as a colorless oil. MS: M+H=481. LC-MS: System 2 (4 min gradient), t R =3.8 min. A portion of this N-Boc ester (0.369 g, 0.768 mmol) was deprotected as described in example 1 with trifluoroacetic acid. The crude product was then coupled with α,α-difluoro-3,4,5-trimethoxyphenylacetic acid (0.241 g, 0.921 mmol), using EDC hydrochloride (0.220 g, 1.15 mmol) and 4-dimethylaminopyridine (0.101 g, 0.826 mmol) in acetonitrile (25 mL). After extractive work up as described in example 1, the product was purified by silica gel chromatography, eluting with hexane/ethyl acetate (4:1 to 1:1), to give the title compound (0.624 g, 1.05 mmol, 78%) as a pale yellow oil. MS: M+H=625. 1 H-NMR: 8.38-8.34 (m, 2H), 7.75-7.00 (m, 7H), 6.76-6.63 (m & s, 2H), 5.25-4.10 (4×m, 2H), 3.80-3.50 (m, 1OH), 3.00-2.85 (m, 1H), 2.52 (m, 2H), 2.25-1.00 (4×m, 16H). LC-MS: System 2 (4 min gradient), t R , for the diastereomers=3.6 and 3.8 min. Anal. C 35 H 42 N 2 O 6 F 2 , C=67.40, H=6.85, N=4.23, F=5.86 (found) C=67.29, H=6.78, N=4.48, F=6.08 (calcd.).
EXAMPLE 5 ##STR14##
N-Boc-L-proline (2.01 g, 9.29 mmol) was esterified with 1,1-dimethyl-3-phenyl propanol (1.83 g, 11.1 mmol) using EDC methiodide (4.14 g, 13.9 mmol) and 4-dimethylaminopyridine (0.100 g, 0.815 mmol) in anhydrous acetonitrile (30 mL) as described in example 4. Following aqueous/organic extractive work up, purification by silica gel chromatography, eluting with hexane:ethyl acetate (95:5 to 80:20), gave pure 1,1-dimethyl-3-phenylpropyl ester (1.13 g, 3.13 mmol, 34%) as a colorless oil. MS: M+H=362. 1 H-NMR: 7.29 (m, 2H), 7.18 (m, 3H), 4.23 & 4.17 (dd, J=8.9 & 3.4 Hz, 1H), 3.60-3.35 (m, 2H), 2.65 (m, 2H), 2.27-1.83 (br m, 6H), 1.46 (s, 4H), 1.44 (s, 6H). A portion of this Boc-protected ester (0.689g, 1.90 mmol) was deprotected with trifluoroacetic acid as described in example 1 and acylated with the p-(methylthio)phenolic ester of α,α-difluoro-3,4,5-trimethoxyphenylacetic acid (0.533 g, 1.39 mmol) in the presence of diisopropylethylamine (0.246 g, 1.90 mmol) in dimethylformamide (10 mL). After extractive work up using ethyl acetate, the crude product was purified by silica gel chromatography, eluting with hexane/ethyl acetate (9:1 to 7:3), to give the title compound (0.350 g, 0.693 mmol, 36%) as a pale brown oil. MS: M+H=506. 1 H-NMR: 7.27 (m, 2H), 7.16 (m, 3H), 6.90 (s, 2H), 4.52 (m, 1H), 3.86 (s, 9H), 3.57 (m, 2H), 2.75-2.50 (m, 2H), 2.20-1.87 (m, 6H), 1.49 (d, J=2.7 Hz, 6H).
EXAMPLE 6 ##STR15##
The coupling of L-proline with the p-(methylthio)phenolic ester of α,α-difluoro-3,4,5-trimethoxyphenylacetic acid was carried out as described in example 5. The intermediate trimethoxydifluorophenylacetamidoproline derivative (0.455 g, 1.26 mmol) was esterified with 1,3-diphenylpropanol (0.325 g, 1.51 mmol) using EDC hydrochloride (0.362 g, 1.90 mmol) and 4-dimethylaminopyridine (0.081g, 0.656 mmol) in anhydrous acetonitrile (20 mL). Following extractive work up, purification by silica gel chromatography, eluting with hexane/ethyl acetate (9:1 to 7:3), gave the desired compound (0.182 g, 0.328 mmol, 26%) as a colorless oil. MS: M+H=554. 1 H-NMR: 7.31 (m, 7H), 7.20 (m, 3H), 6.81 (s, 2H), 5.74 (m, 1H), 4.71 (m, 1H), 3.88 (d, J=7.1 Hz, 3H), 3.78 (d, J=5.5 Hz, 6H), 3.59 (m, 2H), 2.63 (m, 2H), 2.33-1.85 (m, 6H). LC-MS: System 2 (8 min gradient), t R =8.2 min.
EXAMPLE 7 ##STR16##
N-Boc pipecolic acid (0.345 mg, 1.5 mmol) was esterified as described in example 5 with 1,3-diphenyl-1-propanol to obtain the diphenylpropyl ester in 45% yield. MS: M+H=424. LC-MS: System 2 (4 min gradient), t R =4.8 min. A portion of this N-Boc-protected ester (270 mg, 0.64 mmol) was deprotected with trifluoroacetic acid as described in example 1. The resulting trifluoroacetate salt in dichloromethane (4 mL) was acylated with freshly prepared α,α-difluoro-3,4,5-trimethoxyphenylacetyl chloride (201 mg, 1.2 equiv). After 15 h, the solvent was evaporated and the residue was purified by chromatography on reversed phase (C18) silica gel, eluting first with methanol/0.1% trifluoroacetic acid in water (7:3). This was followed by silica gel chromatography of the combined fractions, eluting with ethyl acetate/hexane (3:7), to give a colorless oil (183 mg, 50% yield). MS: M+H=568. 1 H-NMR: 7.38-7.15 (m, 10H), 6.85-6.70 (set of 4 s, 2H), 5.78-5.73 (m, 1H), 5.42-4.60 (2 sets of m, 1H), 4.07-3.67 (m, 10H), 2.97-2.85 (m, 1H), 2.72-2.53 (m, 2H), 2.42-2.08 (m, 3H), 1.85-1.00 (m, 5H). LC-MS: System 2 (4 min gradient), t R =4.6 min. Anal. C 32 H 35 NO 6 F 2 .0.25 CH 3 COOC 2 H 5 , C=67.10, H=6.56, N=2.13, F=6.85 (found), C=67.22, H=6.32, N=2.38, F=6.44 (calcd.).
EXAMPLE 8 ##STR17##
The coupling of L-proline with the p-(methylthio)phenolic ester of α,α-difluoro-3,4,5-trimethoxyphenylacetic acid was carried out as described for example 5. The intermediate timethoxyphenyldifluoroacetamidoproline derivative (0.455 g, 1.26 mmol) was esterified with 3-(3,4,5-trimethoxyphenyl)propan-1-ol as described in example 6 to give the trimethoxyphenylpropyl ester in 42% as a colorless oil. MS: M+H=568. 1 H-NMR: 6.89 (s, 2H), 6.43 (s, 2H), 4.61 (m, 1H), 4.22 (m, 1H), 4.10 (m, 1H), 3.88 (m, 9H), 3.84 (m, 9H), 3.57 (m, 2H), 2.67 (m, 2H), 2.20 (m, 1H), 1.96 (m, 5H). LC-MS: System 2 (8 min gradient), t R =7.0 min.
EXAMPLE 9 ##STR18##
The synthesis of this compound was carried out as as described for example 7. N-Boc pipecolic acid (345 mg, 1.5 mmol) was esterified with 3-(3,4,5-trimethoxyphenyl)propan-1-ol to obtain the trimethoxyphenylpropyl ester in 52% yield. MS: M+H=438. LC-MS: System 2 (4 min gradient), t R =4.2 min. A portion of this Boc-protected ester (325 mg, 0.744 mmol) was deprotected and acylated as described in example 7 with α,α-difluoro-3,4,5-trimethoxyphenylacetyl chloride to obtain 183 mg (42%) of the desired compound. MS: M+H=582. 1 H-NMR: 6.84-6.38 (set of 4 s, 4H), 5.42-4.55 (2×m, 1H), 4.24-3.75 (m, 21H), 3.04-2.96 (m, 1H), 2.67-2.54 (m, 2H), 2.36-2.10 (m, 1H), 2.03-1.15 (m, 7H). LC-MS: System 2 (4 min gradient), t R =4.0 min. Anal. C 29 H 37 F 2 NO 9 .0.25 CH 3 COOC 2 H 5 , C=59.66, H=6.63, N=2.24, F=6.70 (found), C=59.69, H=6.51, N=2.32, F=6.29 (calcd.).
EXAMPLE 10
FKBP12 Rotamase Inhibition Assay
The rotamase activity of FKBP-12 was measured by an adaptation of the assay described by Kofron et al. (Biochemistry, 30, pp. 6127-6134 (1991)). The assay was carried out at 4° C. with 1 mg chymotrypsin/mL of assay solution with succinyl-Ala-Leu-Pro-Phe-p-nitroanilide as the substrate. Chymotrypsin rapidly hydrolyzes the peptide bond on the C-terminal side of the Phe of the trans form of the peptide and releases the chromogenic p-nitroaniline. The rate of the reaction is controlled by the rate of conversion of the cis form of the peptide to the transform, the reaction catalyzed by FKBP12. The apparent K i values of compounds of formula I for inhibition of the rotamase activity were determined by measuring decreases in the first order rate constant of the reaction catalyzed by FKBP12 as a function of the concentrations of the compounds described herein. K i is the concentration of the compound that causes 50% inhibition of rotamase activity which is indicative of neurite outgrowth activity. The results are presented in Table I.
EXAMPLE 11
Assay of Neurite Outgrowth in PC12 Cell Cultures
PC-12A rat pheochromocytoma cells are maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal calf serum and 5% calf serum at 37° C. and 5% CO 2 . Cells to be assayed are plated at 10 4 per well of a 24 well plate an allowed to attach for 4-18 h.
The medium is then replaced with DMEM plus 0.1% BSA (bovine serum albumin), submaximal concentrations of NGF (nerve growth factor) (as determined by neurite outgrowth assay), and varying concentrations of the FKBP12 binding compound (0.1 nM-10 μM) in a final concentration of 0.25% DMSO (dimethylsulfoxide). Control cultures are treated with NGF in the absence of the FKBP12 binding compound. After 72 hours, cultures are fixed with 4% formalin in PBS (phosphate buffered saline), stained with Commassie Blue, and approximately 200 cells are counted in random fields of each well. Cells with neurites longer than one cell diameter are counted as a percentage of total number of cells.
The FKBP12 binding compounds of formula I utilized in this invention cause a significant increase in neurite outgrowth over control cultures.
Additionally, compounds of this invention may also show benefit as reversers of multidrug resistance (MDR) in cancer chemotherapy and as agents for the treatment of HIV infection. Nonimmunosuppressive compounds possessing the structural elements of the FKBP12 binding portion of FK506 have shown utility in reversing P-glycoprotein mediated MDR (U. A. Germann, et al., Anti-Cancer Drugs, 8, pp. 125-140 (1997)). In addition, there has been no direct correlation shown between rotamase inhibitory activity and MDR reversing activity (J. R. Hauske, et al., Bioorg. Med. Chem. Lett., 4, pp. 2097-2102 (1994)). In the area of HIV infection, it is known that immunophilins, including the FK506 binding proteins (FKBPs), are involved in facilitating binding of the HIV envelope protein gp120 to host CD4 receptors (M. M. Endrich, et al., Eur. J. Biochem., 252, pp. 441-446(1998)), and that FK506 inhibits the growth of HIV-infected cells (A. Kapas, et al., Proc. Natl. Acad. Sci USA, 89, pp. 8351-8355 (1992)).
TABLE 1______________________________________Rotamase inhibition data with selected examples ##STR19## Percent K.sub.i InhibitionExample n R (nM) at 10 μM______________________________________1 1 3-phenylpropyl 1300 972 1 3-(3-pyridyl)propyl 877 973 1 4-[7-(3-pyridyl)-1-phenylheptyl] 104 974 2 4-[7-(3-pyridyl)-1-phenylheptyl] 19 985 1 3-(1-phenyl-3-methylbutyl) 706 1 1-(1,3-diphenylpropyl) 83 1007 2 1-(1,3-diphenylpropyl) 948 1 3-(3',4',5'-trimethoxyphenyl)propyl 389 2 3-(3',4',5'-trimethoxyphenyl)propyl 109 99______________________________________
If pharmaceutically acceptable salts of the compounds of formula I are used, those salts are preferably derived from inorganic or organic acids and bases. Included among such acid salts are the following: acetate, aspartate, bisulfate, butyrate, citrate, fumarate, hydrochloride, hydrobromide, hydroiodide, lactate, maleate, oxalate, persulfate, propionate, succinate, tartrate. Base salts include ammonium salts, alkali metal salts, such as sodium and potassium salts, alkaline earth metal salts, such as calcium and magnesium salts, salts with organic bases, such as dicyclohexylamine salts, N-methyl-D-glucamine, and salts with amino acids such as arginine, lysine, and so forth.
Pharmaceutically acceptable carriers that may be used in these pharmaceutical compositions include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat.
The compositions of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir.
It should also be understood that a specific dosage and treatment regimen for any particular patient will depend upon a variety of factors, including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, rate of excretion, and the judgment of the treating physician and the severity of the particular disease being treated. The amount of compound of formula I will also depend upon the particular FKBP12 binding compound in the composition.
The amount of compound of formula I utilized in these methods is between about 0.01 and 100 mg/kg body weight/day.
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The present invention relates to the design, synthesis, and the peptidyl-prolyl isomerase (PPIase or rotamase) inhibitory activity of novel α,α-difluoroacetamido compounds that are neurotrophic agents (i.e. compounds capable of stimulating growth or proliferation of nervous tissue) and that bind to immunophilins such as FKBP12 and inhibit their rotamase activity. This invention also relates to pharmaceutical compositions comprising these compounds.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/465,509, filed Apr. 25, 2003, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a covering and deflector for existing rain gutters and roof-lines and, more particularly, to an improved deflector assembly for channeling rain water into a rain gutter.
[0004] 2. Background of the Related Art
[0005] U.S. Pat. Nos. 4,404,775 and 4,796,390 (which are hereby incorporated by reference), issued to Demartini, describe a deflector assembly which consists of a flat main portion and a curved or arcuate portion located between the main portion and a lower edge. The assembly is positioned above a rain gutter such that the lower edge is located between a front edge and a rear wall of the gutter, and the curved portion is of sufficiently large radius as to extend beyond a trough portion of the gutter and cause water traversing the main portion to be caused, by surface tension, to follow around the curved portion and leave the curved portion at the lower edge. The main portion is held in place with a clip having a substantially straight upper section and a reverse-curved, downwardly oriented lower section, including upward facing tabs in the upper section and downward facing tabs in the lower section to receive the upper edge of an associated rain gutter.
[0006] In principle, water coming from the roof flows onto the main portion of the deflector assembly following its path to the arcuate surface where, through principles of surface adhesion, water will adhere to the surface and be delivered into the gutter as the debris carried by the water is jettisoned off of the arcuate surface. However, difficulties ensue because of how the arcuate portion of the deflector device is attached to the gutter and held in place. Typically, clips such as those described in the prior art, e.g., in the U.S. Pat. No. '390 Demartini patent, are used to hold the deflector assembly in position above the gutter. The clip consists of a lower portion which is curved in a reversed direction to the curve of an upper portion. The lower portion is designed to rest on an upper edge of the outside wall of the gutter and is affixed via tabs to an inside lip of the gutter. The clips are often secured to the gutter by bending the clip down the outside wall of the gutter thus pulling the tab tight to the inside lip of the gutter. The difficulty with clips of this type is that they are not fully stationary at the gutter-clip juncture. Consequently, to facilitate a stable deflector assembly, the top edge of the flat portion of the deflector assembly must be made stationary to the roof via a combination of adhesive strips and by placing nails through the main portion into the roof. Such attachment to the roof prevents horizontal and/or vertical movement from wind and storms which could cause the deflector assembly to be blown off the gutter. The drawbacks of this arrangement are that the adhesive strip increases the cost and time required for installation. Additionally, the nail that is required to make the panel stationary simply introduces one more location on each panel, typically in 3- to 5-foot lengths, wherein water can enter through the shingles into the roof and potentially cause in-wall leaks and destruction of the roof itself. The other limitations of these types of assemblies are that the tabs used to affix the flat portion of the deflector to the clip are made of aluminum and easily break off. Thus, whenever the flat main portion of the assembly must be removed for maintenance purposes, the clips must be replaced. Another limitation is that these deflector assemblies have to be installed by trained technicians and often require two installers to align and attach the assembly to the roof.
[0007] Additionally, whenever the deflector assembly has to be removed from the gutter and roof for maintenance or replacement because of fallen tree limbs and the like, any fasteners or nails having been used to affix the flat portion of the covering to the roof must be removed, and replacing them during reinstallation further increases chances of causing a water pathway through the shingles and into the structure itself. Additionally, seal strips often used in the installation of this type of deflector often remove the grit from the shingles when the deflectors are removed. If deflectors are not replaced, an unsightly tell-tale blemish is left on the roofing where the seal strip was removed.
[0008] [0008]FIG. 1 is a perspective view of a conventional clip coupling a rain gutter and a deflector and FIG. 2 is a cross-sectional view taken along line 2 -- 2 in FIG. 1. In FIG. 1, an existing rain gutter 6 of the usual type is attached to a building adjacent to a roof ( 50 ). This gutter 6 usually has an open top as shown in the left-hand portion of FIG. 1.
[0009] A covering and deflector (e.g., a deflector assembly) for the open rain gutter is shown generally at numeral 8 . This deflector has a closed top portion 1 and an arcuate front portion 26 . The arcuate front portion 26 interfits and affixes to an arcuate portion 7 of either a gutter lip mounting clip 10 or the rear mount clip 30 .
[0010] The gutter lip mounting clip 10 connects to a bottom of a front lip 3 of the rain gutter 6 . FIG. 5 shows a perspective view of the gutter lip mounting clip 10 consisting of a lower portion 4 in which there is a slot 5 used to receive a fastener, e.g., a screw, rivet and the like. To attach the clip 10 to the rain gutter, the fastener is installed through the front lip 3 of the rain gutter 6 and into slot 5 of deflector gutter lip clip 10 , which is hidden from view within the gutter. The deflector is attached to and supported by an upper portion 21 which contains a slot 22 that accepts fasteners. The upper portion 21 and lower portion 4 are connected to one another by an intermediate portion 34 having a generally arcuate form. When installed, the arcuate intermediate portion 34 interfits the inner diameter of the arcuate portion of the deflector. Importantly, to ease installation, the slot 5 of the deflector gutter lip clip 10 is positioned in a extension member 51 that offsets the slot 5 from a centerline of the clip, i.e., slot 22 is laterally offset from slot 5 . As such, an installer has sufficient access to the slot 5 even though the intermediate portion 34 of the clip may extend over the lower portion 4 . Thus, the complex assembly is relatively difficult to install.
[0011] [0011]FIG. 6 depicts a perspective view of the conventional rear mount clip 30 . Rear mount clip 30 is used to mount against rear wall of gutter 6 . The clip is generally triangular in shape and contains a mounting plate 28 , a bracing member 31 and a deflector support member 27 . The clip is typically constructed from a single piece of aluminum or steel. To facilitate mounting the clip to the rear wall of the gutter, upper stops or ears 36 extend from the mounting plate 28 and behind the top edge of the rear wall of gutter 6 . Alternatively, using screws or other fasteners, the mounting plate can be fastened directly to the fascia boards of the building structure. Also, for added stability, both the ears and direct fastening can be used.
[0012] Receiving slots 29 in mounting plate 28 allow for adjustments in height of the arcuate portion 7 of the clip and are fastened with tab 32 at one end of the bracing member 31 . The bracing member contains stops 33 that make the bracing member stationary with respect to the mounting plate 28 Tab 32 of bracing member 31 extends through and beyond receiving slots 29 of mounting plate 28 by ¼ or more. The excess portion of the tab is bent down or twisted at time of installation to keep tab 32 from slipping or being knocked out of receiving slot 29 . The deflector is attached to the deflector support member using fasteners through the deflector and into the slot 22 . When attached, the arcuate portion 7 generally interfits the inner diameter of the arcuate portion of the deflector.
[0013] [0013]FIG. 4 shows a top view of the deflector assembly containing two deflectors 19 and 20 . A top portion 16 of deflector 20 contains attachment apertures 27 , 9 , and 11 and top portion 17 of the deflector 19 contains attachment apertures 13 , 14 , and 15 . To form a continuous covering over rain gutter, the top portion 16 of deflector 20 is joined with the top portion 17 of deflector 19 such that the top portions overlap as generally shown at 18 in FIG. 4.
[0014] As shown in the cross-sectional view of FIG. 3, the right deflector 19 is initially fastened with fastener 23 through attachment aperture 13 and through slot 22 of top portion 21 of gutter lip mounting clip 10 . At the overlap juncture, left deflector 20 is laid over right deflector 19 and fastener 24 is installed through aperture 9 of deflector 20 , aperture 14 of right deflector and through slot 22 of top portion 21 of gutter lip mounting clip 10 . Lastly, fastener 25 is positioned through apertures 16 and 18 of right deflector 20 and left deflector 19 respectively. Alternatively, a rear mount clip could be used in lieu of the gutter lip mounting clip.
[0015] Once the foregoing process is complete, the right 19 and left 20 deflectors are securely fastened to the gutter lip mounting clip 10 by tightening the fasteners. If a rear mount clip is used, slot 22 and arcuate portion 7 of rear mount clip 30 (FIG. 6) are respectively analogous to slot 22 and arcuate portion 7 of gutter lip mounting clip (FIG. 5). As such, once the clips are installed, i.e., to the gutter lip for the gutter lip mounting clip or the rear gutter wall for the rear mount clip, the process for attaching the deflectors to either clip is identical.
[0016] The clips referenced above have several drawbacks when it comes to installation. The clip shown in FIG. 6 is often difficult to install in situations where roof shingles hang down into the gutter and the clip shown in FIG. 5, although ideal in principal, is difficult to install since member 51 of FIG. 5 slides under gutter lip 3 shown in FIG. 2 making it difficult for the installer who desires to self install to run a self tapping screw through lip of FIG. 2 into slot 5 of FIG. 5. Without perfect alignment of the screw with the slot 5 , the screw pushes the clip away from the gutter, preventing the screw from securing the clip to the gutter. Holding the clip to the gutter with a clamp or hand tool, makes installation more difficult as the screw and driving device may additionally clear the clip holding device during installation. Holding the clip to the gutter by hand is dangerous as the screw may easily pierce the hand during installation.
[0017] Therefore, there is a substantial need in the art for an improved clip within a deflector assembly that does not require nailing or gluing the deflector assembly to the roof.
SUMMARY OF THE INVENTION
[0018] A gutter lip mount clip for coupling a gutter deflector to a rain gutter is provided. In one embodiment, the gutter lip mount clip includes an upper portion and a lower portion having a first end connected to the upper portion and a second end. The upper portion is adapted for coupling the clip to an underside of a deflector and includes a plurality of apertures. The apertures are adapted for accepting a fastener for coupling the clip to the deflector. The lower portion is adapted to couple the clip to a gutter lip. In another embodiment, the lower portion includes a hook shaped member that engages the clip to the gutter lip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] So that the manner in which the above recited features of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
[0020] [0020]FIG. 1 is a perspective view of one embodiment of a conventional clip securing a deflector to a rain gutter;
[0021] [0021]FIG. 2 is a sectional view of one embodiment of the deflector and rain gutter, coupled by a conventional clip taken along the line 2 -- 2 of FIG. 1;
[0022] [0022]FIG. 3 is a partial sectional view of the rain gutter, deflector and clip taken along the line 3 -- 3 of FIG. 1;
[0023] [0023]FIG. 4 is a top view of the deflector assembly of FIG. 1;
[0024] [0024]FIG. 5 is a perspective view of one embodiment of a conventional gutter lip mounting clip shown in FIG. 1;
[0025] [0025]FIG. 6 is a perspective view of one embodiment of a conventional rear mount clip shown in FIG. 1;
[0026] [0026]FIGS. 7A-7C are various views of one embodiment of a clip of the present invention;
[0027] [0027]FIG. 7D is a partial sectional view of a clip coupling a deflector to a gutter end cap;
[0028] [0028]FIGS. 8A-8B are side and plan views of another embodiment of a clip of the present invention;
[0029] [0029]FIGS. 9A-9B are top views of alternative embodiments of a clip of the present invention;
[0030] [0030]FIG. 9C is a side view of another embodiment of a clip coupling a deflector to a rain gutter; and
[0031] [0031]FIGS. 10-11 respectively illustrate the clips of FIG. 7A and FIG. 8A coupling a deflector to a gutter.
[0032] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
[0033] As noted in the aforementioned patents, the problems and annoyances involved in keeping rain gutters clean and free-flowing are common knowledge. However, the prior art solutions of screens, mesh, and deflectors for covering a gutter present other problems which in some ways are more burdensome and costly to install than simply periodically cleaning the gutters by hand. Not only do the screens and mesh materials themselves become clogged and blocked, but debris still collects within the gutter, necessitating removal of the screen or mesh before being able to reach the interior of the gutter for cleaning.
[0034] The present invention provides a deflector assembly having a deflector and gutter mount clip. The deflector assembly covers the gutter and prevents it from becoming clogged with leaves and other debris as well as to protect the roof-line from ice and snow damage. The deflector assembly of this invention is designed as two integral units so that leaves, for example, and other debris which may clog the gutter, can neither enter the gutter nor the opening in the deflector that permits rain water to pass into the gutter. The deflector assembly can be easily installed by the average unskilled person without using fasteners or glue strips to attach the assembly to the roof. The gutter mount clips of the deflector assembly to improve the ease with which deflector clips are fastened to the gutter.
[0035] One embodiment of the present invention is an improved clip 710 that can be mounted and affixed to the top of gutter lip 3 as shown in FIGS. 7 A-C and FIG. 10 of the accompanying drawings to attach one or more deflectors to the gutter 6 . The clip 710 has an upper portion 718 , an intermediate portion 720 , and a lower portion 712 . The upper portion 718 is designed to connect with the two deflectors 19 and 20 of the deflector assembly and is coupled to one end of the intermediate portion 720 . The lower portion 712 has a first end 722 , which is coupled to the other end of the intermediate portion 720 , and a second end 724 that terminates at the lower portion's distal end 708 . The lower portion 712 of the clip 710 shown in FIG. 7A is configured to extend above a substantially horizontal top of gutter lip 3 and then horizontally across the top of gutter lip as seen in FIG. 10. An extending member 714 of the lower portion 712 may be angled away from the upper portion 718 to a trough 716 with the intermediate portion 720 (as shown in the clip 910 of FIG. 9C). The trough 716 extends into the gutter below the lip 3 to prevent water entering the gutter from collecting on the lower portion 4 of the clip 10 and subsequently flow back out of the gutter over the gutter lip 3 . An orifice 700 , as shown in FIG. 7B, is formed through the lower portion 712 of the clip 710 through which a fastener 770 can be used to affix the clip 710 to the top of the gutter lip 3 , thereby facilitating assembly of the clip 710 to the gutter 6 by an installer of minimal skill.
[0036] Specifically, FIG. 7B shows the clip 710 prior to forming. The clip 710 is approximately 5 inches long and 1½ inches wide. The orifice 700 has a diameter of approximately ⅛ inch and in one embodiment is located within about ½ of the lower portion's distal end 708 . The orifice 700 may alternatively be a longitudinally oriented slot 780 as seen in FIG. 7C. This clip 710 may be made from aluminum or other malleable material with a thickness ranging from 0.027 inches and 0.032 inches. It is contemplated that the clip may be fabricated to other dimensions.
[0037] In addition, at least two laterally spaced apertures, shown as three laterally spaced sets of apertures 702 , 704 , 706 in FIG. 7B can be positioned on the upper portion 718 to join together the gutter deflector assembly as shown in FIG. 7C identified as 19 and 20 . These apertures typically have a diameter of about {fraction (1/16)} inch.
[0038] The three sets of apertures 702 , 704 , 706 may each comprise one or more holes (two are shown for each set) generally align with the length of the clip 710 and are provided to accomplish the joining depending on whether the apertures are used to join two deflectors 19 and 20 together (as depicted in FIG. 7C) or whether the apertures 702 , 704 , 706 are used for installation of the first deflector in a gutter run either from the right or left side. If starting the installation of a deflector from the right, the apertures 706 on the right most edge of the clip 710 are used so that the leftmost edge of the deflector 19 abuts the edge of the end cap 790 leaving no space over the gutter uncovered and completely covers the clip 710 . The gutter's end cap 790 has a small horizontal flange 794 which overlaps the deflector 19 so that the apertures on the leftmost edge of the deflector 19 , the apertures 706 on the rightmost edge of the clip 710 , and the apertures on the end cap's flange align to accommodate a fastener (as depicted in FIG. 7D). If beginning installation of the gutter deflector from the left end of the gutter, the apertures 702 on the leftmost edge of the clip 710 are used so that the right edge of the deflector 19 abuts the edge of the end cap leaving no space uncovered and completely covers the clip 710 .
[0039] Alternatively, instead of apertures, the upper portion 718 may include one or more slots 902 (shown in FIG. 9A), approximately {fraction (1/16)} inch by 1 inch, positioned on the central axis of the clip 710 . This slot 902 would be positioned behind the arcuate portion 7 of the clip 710 . In another embodiment, a slot 904 may be laterally orientated along the upper portion 718 . Moreover, it is contemplated that a plurality of slots, spaced apart in an orientation substantially perpendicular to the lateral direction, may be positioned on the upper portion 718 of the clip 710 as shown in FIG. 9B.
[0040] In another embodiment, the upper portion 821 may include a plurality of grooves 863 , as shown in FIGS. 8 A-B. These grooves 863 extend across the width of the clip 810 to facilitate breaking off excess portions of the upper portion 821 . In one embodiment, the grooves 863 are spaced approximately every ½ from each other with the first groove being placed approximately 2 inches from the arcuate portion 87 of the clip 810 .
[0041] Referring to the clip 810 shown in FIG. 8A of the accompanying drawings, a lower portion 84 of the clip 810 is modified such that no fasteners such as screws, rivets, and so on need to be used to affix the clip 810 to the gutter 6 (as shown in FIG. 11). To the lower portion 84 , a first leg 862 and a second leg 861 , as shown in FIG. 8A of attached drawings, are added resulting in a U-shaped (from the horizontal) hook member 864 . The open end of the hook member 864 faces the intermediate portion 834 of the clip 810 . This hook member 864 interleaves with the horizontal pre-formed U-shaped edge of the gutter lip 3 , with an open end facing back toward the intermediate portion 834 , as shown in FIG. 11. The hook member 864 may be slid laterally to engage with the U-shaped edge of the gutter lip 3 , or alternatively the hook member 864 and the U-shaped edge of the gutter lip 3 may be dimensioned to allow the engagement of the clip 810 with the lip 3 at the middle of the gutter 6 . This clip 810 may have a slot 22 formed through the upper portion 821 to facilitate coupling to the deflector, or may include two or more apertures, such as the apertures 702 , 704 , 706 in the upper portion 821 as described above. In addition, the clip 810 may include grooves 863 to allow unused portions of the upper portion 821 of the clip 810 to be broken away, thereby allowing one size clip to be used with deflectors of different sizes as shown in FIG. 8A-B.
[0042] In the embodiment depicted in FIG. 8A, the second leg 861 is coupled with about a ⅛ inch radius bend to the first leg 862 . Similarly, the first leg 862 is coupled with about a ⅛ inch radius bend to the lower portion 84 , which in turn is coupled with about a ⅛ inch radius bend to the intermediate portion 834 . The upper portion 821 has a thickness of approximately 0.063 inches and is coupled to the intermediate portion 834 with about a ¼ inch radius bend. The intermediate portion 834 makes approximately a 57 degree angle with the lower portion 84 and approximately a 96 degree angle with the upper portion 821 .
[0043] [0043]FIG. 8B illustrates the clip 810 prior to forming. As shown, about ¼ inch would be allotted for the second leg 861 , about ¾ inch for the first leg 862 , about 1 inch for the lower portion 84 , about 1½ inches for the intermediate portion 834 , about ¼ inch for the arcuate portion 87 , and at least 2½ inches for the upper portion 821 before the first groove is placed. Thereafter, the upper portion 821 consists of grooves 863 separated by approximately ½ inch increments.
[0044] Although various embodiments which incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings.
[0045] While the foregoing is directed to several alternative embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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A gutter lip mount clip for coupling a gutter deflector to a rain gutter is provided. In one embodiment, the gutter lip mount clip includes an upper portion and a lower portion having a first end connected to the upper portion and a second end. The upper portion is adapted for coupling the clip to an underside of a deflector and includes a plurality of apertures. The apertures are adapted for accepting a fastener for coupling the clip to the deflector. The lower portion is adapted to couple the clip to a gutter lip. In another embodiment, the lower portion includes a hook shaped member that engages the clip to the gutter lip.
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This is a continuation of prior application Ser. No. 09/718,592 filed 22 Nov. 2000, now U.S. Pat. No. 6,556,939.
FIELD OF THE INVENTION
The present invention relates to the monitoring of physical processes for early detection of impending equipment failure or process disturbance and on-line, continuous validation of sensor operation. More particularly, the invention relates to systems and methods for the generation of replacement signals for failed sensors or for inferred signals for physical parameters that are not directly instrumented.
BACKGROUND OF THE INVENTION
Monitoring the performance of almost any process (such as in refining, chemicals, steel, energy production) requires the use of sensors to assure that operation is maintained within prescribed constraints and that equipment is performing within specifications to assure acceptable product quality and yield. Performance monitoring and optimization of equipment and machines (automobile systems, jet engines, discrete manufacturing, etc.) similarly relies on sensors to ensure safe operation and peak performance. A plethora of sensors have been developed to measure electrical, thermal, chemical and physical parameters of processes and equipment. Types of sensors include thermocouples, accelerometers, mass flow meters, acoustic sensors, stress and strain indicators, vibration sensors, and so on.
For most important process and equipment monitoring and control applications, sensors are nowadays electrically powered, and provide an electrical indication (either analog or digital) of the parameter that is sought to be measured. Furthermore, in many circumstances, sensors are connected via a bus or network, and may contain sufficient processing power on-board to packetize sensor data and transmit it across a network. In some cases, sensors are connected with or contain wireless transmitters or transceivers for transmission of sensor data to a remote location.
Sensor data can be used in processes or in equipment operation in a variety of ways. Sensors provide validation that control settings have taken effect, and a typical practice is to indicate an alarm when a sensor reading exceeds or drops below a safety or tolerance threshold. Sensor data can also be streamed to a data repository for off-line analysis and trending which is used to schedule maintenance or refine a process. A further use of sensor data is to provide feedback for continuous control of the operation of a process of piece of equipment. In an automobile engine, for example, a number of subsystems use sensor data to compute downstream settings for optimal engine performance, or to meet certain minimum clean air requirements.
There are a variety of circumstances in which it is difficult or impossible to employ a sensor to measure a desired parameter. The environment in which the sensor is placed may be hostile to the longevity or even proper functioning of a sensor, as for example in measuring the flow of a gas containing a problematically high concentration of corrosive acid. Alternatively, the environment may require a sensor that is prohibitively expensive or hard to come by. In another alternative circumstance, the measurement sought may be impossible to reasonably measure directly, as in attempting to determine the remaining empty volume of an unusually shaped chamber partially filled with a liquid. In yet other circumstances, the deployment of a sensor may adversely weaken or otherwise impact the process or system being monitored. For example, in a closed fluid system such as a hydraulic system, placement of a sensor through the wall of the system to directly measure a property of the fluid presents a point of weakness and potential failure in the closed system. What is needed is a way of indirectly measuring the parameter in question.
Under such circumstances, one may attempt to measure one or more other parameters in order to infer the desired parameter. This may require outfitting the process or equipment with additional sensors, and using computing resources to compute the inferred parameter. However, it is generally difficult to successfully do this. Furthermore, it usually requires a great deal of study and knowledge of the process or equipment, or an understanding of the “first-principles” dynamics of the system, which may not be readily obtained without an unreasonable amount of research time and cost. What is needed is an effective way of inferring a hard-to-measure parameter from other measured parameters of a system that correlate in some way, without requiring a complete knowledge of the dynamics of the system and the parameters involved.
Such a need also exists for the circumstance of manufacturing an instrumented product, such as an engine or other machine, which uses sensors for feedback control, safety, or performance optimization. It is highly desirable to reduce the cost of producing the product by not outfitting the product with a sensor for every parameter, but instead inferring some parameters based on readings from other sensors. Such an inference may be possible using a subset of sensors for the machine or engine, coupled with extensive knowledge of the behavior of all the parameters in tandem. However, the requisite knowledge can be difficult and costly to develop. Furthermore, the cost of additional computing power that may be required on-board the product to calculate the inferred sensor values may outweigh the cost savings of removing sensors in the first place. What is needed is a computationally efficient way of inferring values for sensors “removed” from the production units from values of sensors that are in fact built into the production units of the product.
An additional difficulty is presented with the failure of sensors. As an example, sensors may be used to monitor a process or equipment to detect when it deviates from “normal” or correct operation. Normal can mean an acceptable functioning state, or it can be the most preferred of a set of various acceptable states. However, in practice the deviation can be due to a change in the underlying parameter measured by the sensor, or to a faulty sensor. Hence, it is essential that the health of these sensors is also known, and disturbances initiated by sensor faults should be identified and differentiated from process deviations. Often, even though a sensor has failed, it is desirable to continue process operation and the failed sensor must be replaced with a replacement or “virtual” sensor providing the same information. What is needed is a way of providing an output or estimate for a failed sensor within a system to enable continued operation.
“First principles” techniques are known in the art for generating “virtual” sensor data based on other real sensor data. Maloney et al. describe in “Pneumatic And Thermal State Estimators For Production Engine Control And Diagnostics”, Electronic Engine Controls 1998, estimator algorithms implemented in a production grade speed-density Engine Management Systems (EMS). A critical and basic need in the design of EMS control and diagnostic algorithms is the availability of information describing the state of the engine. The estimator algorithms provide engine mass flow, pressure, and temperature estimates for general use by control, diagnostic, and other estimator algorithms. Maloney et al. describe the development of such first principles models with fully instrumented engines in the laboratory, to compute virtual signals off of real sensor signals. The development is involved and highly specific to the application presented. It would thus be desirable to provide a general method for the generation of missing values or virtual signals without have to resort to developing first principles models.
In a related trend, processes or machines are monitored by software-based systems that monitor correlated sensor values in aggregate. Such a system is described in U.S. Pat. No. 5,764,509 to Gross et al., the teachings of which are hereby incorporated by reference. Such a system for monitoring or providing control over a process or machine is superior to traditional threshold-type sensor-based monitoring and control because it can generally differentiate the normal or acceptable behavior of the process or machine from unacceptable or alarm states long before the threshold system. Gross et al. teach an empirical modeling technique that accepts as inputs a set of current sensor readings for linearly and non-linearly correlated parameters of the monitored process or machine, and generates estimates as outputs of what those current sensor readings ought to be. This is then compared using a statistical hypothesis test for each sensor to determine whether any sensor is showing a statistically significant deviation from what is expected. The empirical model of Gross et al. is created from a history of collected data representing the expected ranges of operation for the monitored process or machine.
An important issue for such a system is the robustness of the system when presented with a failure of a sensor, as opposed to a process or functional deviation. A bad sensor signal input to such a system potentially can impact the estimates made by the model for all the sensors in the process or machine. Furthermore, other control modules outside the monitoring system may be relying on the bad sensor signal. It would be beneficial in such systems to reduce the impact of a failed sensor on the ability of the system to generate accurate estimates and therefore accurately portray the operational state of the process or machine. It would be additionally advantageous to be able to generate a replacement signal for the failed sensor and make it available to any other control systems that normally rely on raw real-time sensor signals. There is a need for a way to handle a bad sensor under these circumstances in an empirical modeling system like that by Gross et al.
SUMMARY OF THE INVENTION
The present invention provides an improved system and method for producing replacement sensor signals for failed sensors, and inferred sensor signals for non-instrumented physical parameters, in processes and equipment having one or more sensors in place for monitoring physical parameters. The system can provide expected parameter values, as well as the differences between expected and input signals; or the system can provide raw measures of similarity between the collection of input signals and the collection of acceptable modeled states.
In a process or machine that is fully instrumented with sensors for all parameters of interest, sensor data is collected for all regimes of expected later operation of the same or similar processes or machines. This collected data forms a history from which the inventive system can “learn” the desired or normal operation of the process or machine, using training routines that distill it to a representative set of sensor data. Using this representative training set of sensor data, the described embodiments monitor the process or machine in real-time operation (or in batch mode, if preferred), and generate estimates for certain of the sensors for which historic data was collected, but which have failed or which were removed from the process or machine. The invention can be employed as a safeguard that is triggered to produce a replacement sensor signal when an actual sensor fails (an autoassociative or replacement mode). It can also be used to produce an inferred sensor signal to reduce the production cost of a machine by reducing the number of sensors that are needed to monitor and control the machine (an inferential mode).
The apparatus of the present invention can be deployed as an electrically powered device with memory and a processor, physically located on or near the process or machine for which the “virtual” signal is generated. Alternatively, it can be located remotely from the process or machine, as a module in a computer receiving sensor data from live sensors on the process or machine via a network or wireless transmission facility. The replacement or inferred sensor signals generated accordingly may be returned to a control system or display system local to the process or machine, or located at the remote location or yet a different remote location.
A memory for storing the representative training set, or a transformation thereof, is coupled to a processor. The processor receives from an input data signals embodying real values from sensors actually on the process or machine, and may receive these in real-time. The processor is disposed to take a set of readings of the actual sensors from the input, and generate an estimate of one or more desired inferred sensors, using a linear combination of the representative training set sensor data, as weighted by the result of a measure of similarity of the input sensor data to the representative training set sensor data.
Accordingly, it would be advantageous to provide a method of generating an estimate of a physical parameter of a process or machine based on sensor values for other physical parameters of the process or machine, and based on a set of sensor data for the process or machine representative of past operation. The improved monitoring system may accept an input set of sensor data for a process or machine, and provide as output at least one estimate of a parameter of the process or machine that is not among the sensor inputs. A computationally efficient method and apparatus for generating a replacement signal for a parameter in a sensor-monitored process or machine is also desirable when it is determined that a sensor has failed. To this end, it would be advantageous to provide a computer-executable module for generating a replacement sensor signal for a failed sensor, or an inferred sensor signal for a non-instrumented parameter, based on an input of other parameters or a process or machine, and for outputting the estimate to a display or control system. A microprocessor-based component may be added to a machine to interface with sensor data in the machine to provide inferred estimates of at least one additional physical parameter of the machine not measured by sensors.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as 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, wherein:
FIG. 1 illustrates steps for setting up inventive virtual signal generation for a process or machine;
FIG. 2 illustrates a method for creating a representative “training” data set from collected sensor data for use in the invention;
FIG. 3 illustrates a flowchart for creating a representative “training” data set from collected sensor data for use in the invention;
FIG. 4 is a diagram of an arrangement for obtaining a data set history for a machine, for use in the present invention;
FIG. 5 illustrates an on-board processor embodiment of the present invention for generating virtual signals for a monitored or controlled machine or process;
FIG. 6 illustrates a remote monitoring embodiment of the present invention for generating virtual signals for a monitored or controlled machine or process;
FIG. 7 illustrates a flowchart for generating a set of one or more virtual sensor signals according to the present invention;
FIG. 8 illustrates the computation of one of the similarity operators of the present invention;
FIG. 9 illustrates a flowchart of decision logic for generating a replacement virtual signal in a monitored process or machine according to the invention;
FIG. 10 illustrates a hydraulic system capable of being monitored by with the present invention using a complex signal; and
FIG. 11 shows a chart of a virtual signal generated as compared to the corresponding actual sensor signal in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1 , a flowchart generally shows the steps for setting up and using a process, machine, system or other piece of equipment, whether mechanical, electrical or biological in accordance with the invention. In step 110 , a described embodiment of the process or machine from which inferred or replacement signals may be generated in operation, is fully instrumented with sufficient sensors to measure all parameters of interest, including the parameters for which virtual signals will be generated. In step 120 , sensor data is collected as the prototype is operated through all ranges of operation that are expected later. In step 130 , one of several “training” methods is used to distill the sensor data collected in step 120 into a subset sufficient to representative the operational ranges and correlations between the sensors over those ranges. These methods will be discussed below. In step 140 , the distilled representative sensor data or a transformation of that data, including data elements corresponding to each of the (all) sensors with which the prototype was instrumented, is loaded into a processor memory that will provide for generation of virtual sensor signals for the process or machine in normal operation. In step 150 , the application for generating virtual sensor signals is as replacement sensor signals for sensors that fail in operation. In step 160 , the application for generating virtual sensor signals is as inferred signals for sensors that are removed or not built into production runs of like machines or equipment, thus saving the cost of the absent sensors while nonetheless providing signals for downstream processing.
The described embodiments substantially provide the process or machine for which virtual signals will be generated in operation. For example, in the case of an engine, a prototype engine can be fully instrumented in a laboratory bench setting with sensors for all parameters. The prototype engine is then operated through a variety of operational ranges, and sensor data for all the sensors is recorded, usually as digitized and time-stamped values by means of digital computers attached to and in communication with the sensor outputs. Using the computer processor and software of the described embodiments, the collected sensor data is then distilled down to a subset of sensor data that represents the operational ranges for which data was collected. Where the goal is to mass produce this engine with a reduced cost of production by building in fewer sensors, but still have all the sensor signals available for engine monitoring and control, the distilled representative data is provided in an inventive computer software module and processor hardware for executing it, that can be built into the engine monitoring or control system, and that generates virtual signals for the missing sensors as detailed below. The system described in the preferred embodiments provides for monitoring of the instrumented equipment with a plurality of sensors capable of being monitored with an information processor. A data acquisition input front end is provided for use with the information processor for receiving operational values descriptive of physical parameters of the system. Time-correlated sensor data representative of expected operational states and signals observed from the instrumented equipment during operation are used by the information processor for generating outputs that are descriptive of a parameter that may include or be provided in addition to signals observed from the instrumented equipment. The information processor is operable in response to the plurality of sensors of the instrumented equipment for establishing relationships between the component signals and one or more process parameters of the equipment to generate one or more parametric signals corresponding to process parameters of the system.
As another example, for a process in which it is desirable to measure a parameter that would require placing a sensor in a corrosive or destructive environment, a mock-up of the process can be constructed in a laboratory setting, fully instrumented. The mock-up can be operated through the expected ranges of later operation, and data collected over these ranges. While one or more sensors may eventually be destroyed this way until enough data is collected, the subsequent inventive inferential model will enable full-scale operation of the process in question without any subsequent need to replace further destroyed sensors. The parameter can be generated in operation by the computer module of the described embodiments, referencing the representative data distilled from data collected in the laboratory.
The amount of historic data that must be collected to provide for the representative training set is of course contingent on the specific application and the variety of operational modes and ranges that will be encountered in normal monitored operation, but in any case usually represents much less time and effort than is required to study the system through all its ranges to derive a first-principles model of the system. Importantly, the data collected should include both sides of any hysteresis present in the operational modes.
The described embodiments thus provide an extremely beneficial empirical approach to providing replacement sensor signals or inferred sensor signals for process or machine monitoring or control. It avoids the lengthy or perhaps insurmountable task of developing a first-principles model and understanding of the relationships between all the instrumented parameters.
Turning to FIG. 2 , a method for step 130 is graphically depicted for distilling the collected sensor data from step 120 to create a representative training data set. Five sensor signals 202 , 204 , 206 , 208 and 210 are shown for a process or machine in which later one or more of the five will be inferentially generated. The abscissa axis 215 is the sample number or time stamp of the collected sensor data, where the data is digitally sampled and the sensor data is temporally correlated. The ordinate axis 220 represents the relative magnitude of each sensor reading over the samples or “snapshots”. Each snapshot represents a vector of five elements, one reading for each sensor in that snapshot. Of all the sensor data collected in step 120 (all the snapshots), according to this training method, only those five-element snapshots are included in the representative training set that contain either a global minimum or a global maximum value for any given sensor. Therefore, for sensor 202 , the global maximum 225 justifies the inclusion of the five sensor values at the intersections of line 230 with each sensor signal, including global maximum 225 , in the representative training set, as a vector of five elements. Similarly, for sensor 202 , the global minimum 235 justifies the inclusion of the five sensor values at the intersections of line 240 with each sensor signal.
Selection of representative data is further depicted in FIG. 3 . Data collected in step 130 has N sensors and L observations or snapshots or temporally related sets of sensor data that comprise an array X of N rows and L columns. In step 304 , a counter i for element number is initialized to zero, and an observation or snapshot counter t is initialized to one. Two arrays “max” and “min” for containing maximum and minimum values respectively across the collected data for each sensor, are initialized to be vectors each of N elements which are set equal to the first column of X. Two additional arrays Tmax and Tmin for holding the observation number of the maximum and minimum value seen in the collected data for each sensor, are initialized to be vectors each of N elements, all zero.
In step 307 , if the sensor value of sensor i at snapshot t in X is greater than the maximum yet seen for that sensor in the collected data, max(i) is update to equal the sensor value and Tmax(i) stores the number t of the observation in step 310 . If not, a similar test is done for the minimum for that sensor in steps 314 and 317 . The observation counter t is incremented in step 320 . In step 322 , if all the observations have been reviewed for a given sensor (t=L), then t is reset and i is incremented (to find the maximum and minimum for the next sensor) in step 325 . If the last sensor has been finished (i=N), step 328 , then redundancies are removed and an array D is created from a subset of vectors from X.
First, in step 330 , counters i and j are initialized to one. In step 333 , the arrays Tmax and Tmin are concatenated to form a single vector Ttmp having 2N elements. These elements are sorted into ascending (or descending) order in step 336 to form array T. In step 339 , holder tmp is set to the first value in T (an observation number that contains a sensor minimum or maximum). The first column of D is set equal to the column of X corresponding to the observation number that is the first element of T. In the loop starting with decision step 341 , the ith element of T is compared to the value of tmp that contains the previous element of T. If they are equal (the corresponding observation vector is a minimum or maximum for more than one sensor), it has already been included in D and need not be included again. Counter i is incremented in step 350 . If they are not equal, D is updated to include the column from X that corresponds to the observation number of T(i) in step 344 , and tmp is updated with the value at T(i). The counter j is then incremented in step 347 . In step 352 , if all the elements of T have been checked, then the distillation into training set D has finished, step 355 .
Turning to FIG. 4 , a schematic diagram of a laboratory workbench arrangement is shown for gathering process or machine behavior data for distillation. A machine prototype 410 is depicted, which may be any kind of machine for which virtual sensors are required or desirable. For example, machine 410 may be a combustion engine, an electric motor, a pump, a compressor, a refrigerator, and so on. The machine 410 is called a prototype, but importantly, it should generate sensor data that is substantially the same as the actual parameter values expected in a production model of the machine, as would be measured by the same sensors. Of course, the prototype may also be an instance of the production model itself, and ideally need not differ in any way from other production models. The machine 410 may be connected to and controlled by a control system 420 , generally comprising a microcontroller-or microprocessor-based digital system with appropriate analog/digital and digital/analog inputs and outputs as necessary. Machine 410 is instrumented with sensors that provide sensor values along outputs 430 . While all parameters of interest are instrumented in this laboratory workbench arrangement, it is understood that only a subset 440 of the sensors will be employed in a production model of; the machine 410 , while a second subset 450 of sensors will not be employed or cannot be reliably employed in the production model of the machine 410 . This may be done to avoid costs for sensors 450 , or may be due to the difficulty or impossibility of employing sensors 450 for as long as needed in the production model. The machine 410 is operated through the expected range of operations, and data acquisition system 460 may be used to then record the values of all sensors 430 with which machine 410 is instrumented. Additionally, control signals from control system 420 may also be recorded by data acquisition system 460 , and may be used as “sensor signals” that correlate with the other sensor signals.
Data acquired by data acquisition system 460 can accordingly be processed using a computer module 480 for producing a distilled training set of data representing the operational ranges of machine 410 , using the training method described above, or other methods as may be known in the art.
In the presently described embodiment an on-board processor is shown in FIG. 5 , wherein a machine (or process) 508 is controlled by a control system 517 that is located on the machine. Machine 508 is instrumented with sensors for some of the physical or logical parameters of interest in controlling the machine, and the outputs for these sensors are shown as output conductors 523 , which feed into the control system 517 . These are also feed to a processor 545 located within or on the machine, disposed to execute a computing program for generating a set 530 of at least one virtual signal from the signals on the output conductors 523 . The processor is connected to a memory 551 , also on or in the machine, which stores data comprising the training set distilled to represent the expected operational states of the machine 508 . Memory 551 can also advantageously store programs for execution by the processor 545 . The virtual signals 530 generated by the processor 545 are provided to the control system 517 , in lieu of genuine sensor values for physical or logical parameters of the machine. In this way, using a processor and memory located on or within the machine, the control system for the machine can advantageously be provided with sufficient physical parameter values of the machine to effectively control it, even if some of the physical parameters have not been instrumented, due to cost savings considerations, or due to the impracticability of instrumenting one or more physical parameters.
Processor 545 can also be a part of the control system 517 , and in fact can be the processor on which the control system routines are executed, in the event the control system is a digital computed control system. Ideally, the processor 545 and memory 551 are powered by the same power source as the control system. However, under certain circumstances, it may also be preferable to provide for a processor and memory independent from the processor and/or memory of the control system, in order to provide virtual signals 530 in a timely fashion, as though they were truly instrumented parameters. For example, it may be necessary that processor 545 must operate at a higher clock speed than any processor available within the control system, in order to provide virtual signals in a way that appears to the control system indistinguishable from a genuinely instrumented parameter. Also, processor 545 and memory 551 can comprise a separate unit from the control system with its own power supply that can be retrofitted to an existing machine and control system.
According to another embodiment, a process 603 is shown in FIG. 6 to be instrumented with sensors having output leads 606 . These provide sensor signals to a control system 610 that controls the process. These signals are also provided to a remote communications link 613 , which is disposed to communicate digital values of the sensor signals to a second remote communications link 615 , located at a physically remote place. A processor 618 is provided, which may comprise a computing system and software, that uses the sensor signals received by link 615 to generate at least one virtual sensor signal indicative of an inferred physical parameter of process 603 . A memory 620 is provided to store training set data representative of the expected operational behavior of the process 603 , according to the distillation method described above. Furthermore, a display 623 may be provided at the remote location for displaying data descriptive of the process 603 , comprising sensor signals 606 or the virtual signals derived therefrom or both. The virtual signals generated by processor 618 can also be transmitted from link 615 back to link 613 and input over leads 627 to control system 610 for advantageous control of the process. Data comprising original sensor signals and/or virtual sensor signals can also be transmitted to a third remote communications link 630 , located at yet a third distant place, for display on display 633 , thereby providing valuable information concerning the process to interested parties located at neither the physical plant of the process nor at the site of computing the virtual signals.
The remote communications links can be selected from a variety of techniques known in the art, including internet protocol based packet communication over the public telecommunications infrastructure, direct point-to-point leased-line communications, wireless or satellite. More specifically, remote links 613 , 615 and 630 may be internet-enabled servers with application software for accumulating, queuing and transmitting data as messages, and queues for receiving and reconstituting data arriving as messages. Alternatively, communications can be synchronous (meaning in contrast to asynchronous, message-based communications) over a wireless link.
The embodiment of the invention shown in FIG. 6 provides computation of the virtual signals using computing resources that are located geographically distant from the process (or machine) being monitored and/or controlled with the virtual signals. One benefit of this is that the computing resources for generating the virtual signals may be shared for a multitude of processes or machines, where the memory 620 may hold multiple sets of training sets of data characterizing the various monitored processes and machines. Another benefit is that the virtual signal results may be displayed and also potentially used in further analysis by interested parties located distant from the process being monitored.
The calculations to be carried out by the information processor are described in detail below. Using as an example a machine that will be mass produced that has fifteen total physical parameters of interest, we assume ten of these will be instrumented with real sensors providing real signals during machine operation, and five signals will be inferred from the first ten, thereby reducing the cost to produce the machine by the cost of the sensors for these five parameters. In what follows, the subscript “in” generally corresponds to the ten real sensors whose values are input to the calculations, and the subscript “out” generally corresponds to the five inferred sensor values that are output by the calculation.
The step of providing a representative training set according to the description above results in a matrix D of values, having fifteen rows (corresponding to all fifteen parameters measured in the test or lab setting) and a sufficient number n of columns (sets of simultaneous or temporally related sensor readings) to properly represent the full expected dynamic operating range of the machine. The matrix D comprises two adjoined matrices, D in and D out , each having n columns: D in has ten rows (corresponding to the ten real sensors) and D out has five rows, corresponding to the five inferred sensors. While the order of the columns does not matter in D, the ith column in both D in and D out must correspond.
Then, using y in to designate a vector having ten elements corresponding to the values of the ten real sensors (preferably in real-time), a vector y out is generated having five elements corresponding to the five inferred sensor values, according to:
{right arrow over (y)} out ={overscore (D)} out ·{right arrow over (W)}
where W is a weight vector having as many elements N as there are columns in D, generated by:
W → = W ^ → ( ∑ j = 1 N W ^ ( j ) )
W ^ → = ( D _ i n T ⊗ D _ i n ) - 1 · ( D _ i n T ⊗ y → i n )
where {circle around (x)} represents a similarity operation between the two operands described in greater detail below that yields an array. The superscript “T” here represents the transpose of the matrix, and the superscript “− 1 ” represents the inverse of the matrix or resulting array. Importantly, there must be row correspondence to same sensors for the rows in D in and y in , and for D out and y out . That is, if the first row of the representative training set matrix D in corresponds to values for a first sensor on the machine, the first element of y in must also be the current value (if operating in real-time) of that same first sensor.
Turning to FIG. 7 , the generation of one or more replacement or inferred signals is shown in a flowchart. The flowchart shows the generation of one replacement or inferred signal in the described embodiments, provide input of one snapshot of actual sensors values in real-time operation. Matrix D in is provided in step 705 , along with the input snapshot vector y in and an array A for computations. A counter i is initialized to one in step 708 , and is used to count the number of observations in the training matrix D in . In step 712 , another counter k is initialized to one (used to count through the number of sensors in a snapshot and observation), and array A is initialized to contain zeroes for elements.
In step 715 , the element-to-element similarity operation is performed between the kth element of y in and the (ith, kth) element in D in . These elements are corresponding sensor values, one from actual input, and one from an observation in the training history D in . The similarity operation returns a measure of similarity of the two values, usually a value between zero (no-similarity) and one (identical) which is assigned to the temporary variable r. In step 720 , r divided by the number of sensors M is added to the ith value in the one-dimensional array A. Thus, the ith element in A holds the average similarity for the elemental similarities of y in to the ith observation in D in . In step 724 , counter k is incremented.
In step 729 , if all the sensors in a particular observation in D in have been compared to corresponding elements of y in , then k will now be greater than M, and i can be incremented in step 731 . If not, then the next element in y in is compared for similarity to its corresponding element in D in .
When all the elements of the current actual snapshot y in have been compared to all elements of an observation in D i , a test is made in step 735 whether this is the last of the observations in D in . If so, then counter i is now more than the number of observations N in D in , and processing moves to step 738 . Otherwise, it moves back to step 712 , where the array A is reset to zeroes, and the element (sensor) counter k is reset to one. In step 738 , a weight vector W-carrot is computed from the equation shown therein, where {circle around (x)} represents a similarity operation, typically the same similarity operator as is used in step 715 . In step 743 W-carrot is normalized using a sum of all the weight elements in W-carrot, which ameliorates the effects in subsequent steps of any particularly large elements in W-carrot, producing normalized weight vector W. In step 746 , this is used to produce the replacement or inferential output y out using D out . The output vector may have just one element, in the case that only one replacement or inferential signal is being generated, or it may have multiple elements, corresponding to each “virtual” sensor being generated. The matrix D out has been described above as containing counterpart training data for the sensor(s) being generated.
The similarity operation can be selected from a variety of known operators that produce a measure of the similarity or numerical closeness of rows of the first operand to columns of the second operand. The result of the operation is a matrix wherein the element of the ith row and jth column is determined from the ith row of the first operand and the jth column of the second operand. The resulting element (i,j) is a measure of the sameness of these two vectors. In the described embodiment, the ith row of the first operand generally has elements corresponding to sensor values for a given temporally related state of the machine, and the same is true for the jth column of the second operand. Effectively, the resulting array of similarity measurements represents the similarity of each state vector in one operand to each state vector in the other operand.
By way of example, one similarity operator that can be used compares the two vectors (the ith row and jth column) on an element-by-element basis. Only corresponding elements are compared, e.g., element (i,m) with element (j,m) but not element (i,m) with element (j,n). For each such comparison, the similarity is equal to the absolute value of the smaller of the two values divided by the larger of the two values. Hence, if the values are identical, the similarity is equal to one, and if the values are grossly unequal, the similarity approaches zero. When all the elemental similarities are computed, the overall similarity of the two vectors is equal to the average of the elemental similarities. A different statistical combination of the elemental similarities can also be used in place of averaging, e.g., median.
Another example of a similarity operator that can be used can be understood with reference to FIG. 8 . With respect to this similarity operator, the teachings of U.S. Pat. No. 5,987,399 to Wegerich et al. are relevant, and are incorporated in their entirety by reference. For each sensor or physical parameter, a triangle 804 is formed to determine the similarity between two values for that sensor or parameter. The base 807 of the triangle is set to a length equal to the difference between the minimum value 812 observed for that sensor in the entire training set, and the maximum value 815 observed for that sensor across the entire training set. An angle Ω is formed above that base 807 to create the triangle 804 . The similarity between any two elements in a vector-to-vector operation is then found by plotting the locations of the values of the two elements, depicted as X 0 and X 1 in the figure, along the base 807 , using at one end the value of the minimum 812 and at the other end the value of the maximum 815 to scale the base 807 . Line segments 821 and 825 drawn to the locations of X 0 and X 1 on the base 807 form an angle θ. The ratio of angle θ to angle Ω gives a measure of the difference between X 0 and X 1 over the range of values in the training set for the sensor in question. Subtracting this ratio, or some algorithmically modified version of it, from the value of one yields a number between zero and one that is the measure of the similarity of X 0 and X 1 .
Any angle size less than 180 degrees and any location for the angle above the base 807 can be selected for purposes of creating a similarity, but whatever is chosen must be used for all similarity measurements corresponding to particular sensor and physical parameter of the process or machine. Thus, differently shaped triangles 804 can be used for different sensors. One method of selecting the overall shape of the triangle is to empirically test what shape results in consistently most accurate virtual signal results.
For computational efficiency, angle Ω can be made a right angle (not depicted in the figure). Designating line segment 831 as a height h of the angle Ω above the base 807 , then angle (θ) for a given element-to-element similarity for element i is given by:
θ i = tan - 1 ( h X 1 ( i ) ) - tan - 1 ( h X 0 ( i ) )
Then, the elemental similarity is:
s i = 1 - θ i π / 2
As indicated above, the elemental similarities can be statistically averaged or otherwise statistically treated to generate an overall similarity of a snapshot to another snapshot, as if called for by the system.
Yet another class of similarity operator that can be used in the described embodiments involves describing the proximity of one state vector to another state vector in n-space, where n is the dimensionality of the state vector of the current snapshot of the monitored process or machine. If the proximity is comparatively close, the similarity of the two state vectors is high, whereas if the proximity is distant or large, the similarity diminishes, ultimately vanishingly. By way of example, Euclidean distance between two state vectors can be used to determine similarity. In a process instrumented with 20 sensors, for example, wherein a 21 st uninstrumented parameter is beneficially inferred, the Euclidean distance between the currently monitored snapshot, comprising a 20 element state vector, and each state vector in the training set (comprising a 20 element vector where the 21 st element corresponding to the virtual sensor has been left out) provides a measure of similarity, as shown:
S = 1 [ 1 + x → - d → λ c ]
wherein X is the current snapshot, and d is a state vector from the training set, and λ and c are user-selectable constants.
Turning to FIG. 9 , decision logic is depicted for a method of checking for failed sensors and generating replacement signals in response thereto according to the invention. Such a method can be embodied in a processor and memory as would be known in those skilled in the art, to provide a system for monitoring a machine or process in real-time and generating one or more replacement virtual signals as necessary in response to a detected failure of a sensor on the machine or process. In step 903 , a FLAG variable is initialized to zero, and a snapshot counter t is also initialized to zero. On the first loop through the method, if t is zero in step 906 , then initial training is carried out in step 908 . A training set 912 distilled in the described embodiment provides a training matrix of snapshots 917 . In step 908 , the matrix D in and D out are set equal to matrix D of 917 , the FLAG is set to zero, t is set to 1 and an intermediate matrix G 0 is found by:
G 0 −1 =( D in 0 T {circle around (x)}D in 0 ) −1
using the similarity operation.
Real-time or on-line monitoring of the machine or process by acquisition of real sensor data 920 then proceeds in step 922 , wherein a snapshot X t of time-correlated or coincident data is acquired from sensors on the machine or process.
The acquired data is used to compute estimated values for all the sensors according to:
{circumflex over (X)} t =D out ·G t −1 ·( D in t T {circle around (x)}X t )
Such an estimate of all the sensors has utility as is known in the prior art, such as Gross et al. mentioned above, for comparing to the real sensor values and detecting when a process change is occurring. As can easily be discerned from this figure, if no sensors on the monitored machine or process have failed, then the matrices D out and D in (0) are equivalent.
A decision engine in step 926 examines whether any sensors have failed. Any of a variety of techniques known in the prior art for detecting sensor failure can be used, and can work by examining just the original monitored data or by comparing the monitored data to the estimated data. By way of example, one technique for determining whether a sensor has failed is to monitor whether the reading from the sensor has frozen at a single value over a sequence of readings over which it should have changed. As another example, sensor failure can be determined when a sensor reading suffers a sharp discontinuity or drops to zero, especially when the physical parameter being measured by the sensor cannot possibly be zero. In addition, certain “smart” sensors are available commercially that provide an indication that they have failed. In step 930 , if one or more sensors have failed, they are flagged in step 933 , and the FLAG variable is set to one. If no sensors have been determined as failed, then processing continues at step 906 .
Returning to step 906 , t is now not equal to zero, having been set to one in step 908 . The counter t is incremented in step 937 , corresponding to a reading of the next snapshot of data from genuine sensors. Upon checking the state of FLAG in step 940 , if FLAG is still zero (no sensor has failed since the last loop through the process), then D in and G remain the same in step 945 , and the next snapshot is acquired and processed continuing with step 922 again. If, on the other hand, FLAG has been set to one in step 933 as checked in step 940 , then the arrays D in and G must be recalculated in step 950 . Rows are removed from D in , corresponding to the failed sensors (these are not removed from D out ). Array G is recalculated based on the new D in . The FLAG is reset to zero. Then, in step 922 , as the snapshot of the monitored process or machine is acquired, elements of the input vector X corresponding to the same failed sensors are removed. However, since D out has not had any rows removed, the estimate of X generated in step 922 includes estimates for the missing rows, that is, failed sensors. These estimates are thus the virtual sensor values computed as replacement values for the failed sensors.
Thus the embodiment advantageously provides the ability to generate replacement signals on-the-fly for failed sensors in monitoring systems employing a similarity operation for computing estimates for comparison to actual data. Such a replacement signal can be provided to downstream processing that requires a sensor signal from the failed sensor(s). Accordingly, a complex sensor signal can be decomposed into multiple correlated inputs to provide an inferential measure of an uninstrumented physical parameter of a system.
Turning to FIG. 10 , a hydraulic pump embodiment 100 is shown in which a diesel engine 102 drives a shaft 104 of the hydraulic system 100 , which actuates a piston 106 in a cylinder 108 for controlling the hydraulic supply being provided by four-way directional valve 110 . In the described embodiment, an eight-step cycle is provided for the hydraulic system to facilitate variable flow rates. The system 100 is outfitted with an accelerometer 112 , preferably located so as to observe vibrations longitudinal with the variable displacements of the pump cylinders associated with the pistons 106 reciprocating therein. The introduction of contaminants in the hydraulic loop, such as particles and metallic grains or the like, wear on the valve and piston of the system, causing changes in the hydraulic pressure. This results in changes in vibrations from the pump, as it may compensate for the loss of pressure.
The parameter desirably estimated with a virtual signal in connection with the hydraulic system 100 can be the pressure or flow provided by the system. An invasive pressure transducer in the hydraulic line, however, can be obstructive and susceptible to failure. Accordingly, the accelerometer 112 is desirably used instead to facilitate virtual pressure readings correlated with the accelerometer 112 . This is accomplished by outputting the complex signal from accelerometer 112 to a power spectrum analyzer 114 , which can be embodied in a computer running a software module, with a data acquisition device attached to the accelerometer 112 . The power spectral density (PSD) output by the analyzer 114 provides the power of the accelerometer-measured vibration as a function of the frequency of that vibration, using a 1024 sample fast Fourier transform (FFT) sliding window providing for frequency bins which may be user selectable, e.g., 30 frequency bins over the power spectrum being provided as an input observation vector for the similarity calculations as discussed above. Accordingly, the frequency components associated with the user selectable bins provide multiple input observations. The PSD can be used as a multi-variable input to the inferential signal generator. The uninstrumented physical parameter of hydraulic pressure, or flow as desired, is the inferred signal. The inputs from the PSD are the actual signals. These inputs can be selected from the following several alternatives.
In the first alternative, selected frequencies only can be used as inputs. For example, with some knowledge of the vibration frequencies likely to be of interest in the hydraulic system 100 , several frequencies can be selected, and the value of the power at each of these frequencies can be used as a “sensor” input.
In another alternative, the frequencies can be “binned” or tallied across several bands of frequencies. In this case, the value (or “sensor” signal) for a given band or bin of frequencies can be one of the highest power value in the bin, the lowest power value in the bin, the average power value across the bin, or the median power value in the bin. Other variations clearly would also work, and are within the scope and spirit of the invention.
Thus, the described embodiments provide the benefit of working with decomposed complex signals as input to inferring an uninstrumented physical parameter. In an exemplary embodiment, data was collected from a standard window-mounted room air conditioner operating over a variety of expected conditions, in a large room serving as a thermal sink. The outputs from a total of 23 sensors were used and represented measurements of the temperature gradients across the evaporator and condenser. The data were acquired from k-type thermocouples that were digitized using a data acquisition board (DAQ) with a sampling rate setting of 100 samples/sec. The data were collected while the air conditioner maintained the room environment at a relatively constant temperature. The data was distilled to a training set according to the methods described herein. A large number of training snapshots (92, four times the number of sensor variables) relative to the number of sensors were employed to develop the empirical model of the air conditioner in operation.
To measure the fidelity of the empirical model, a total of 600 randomly chosen operating observations were estimated using the model developed from the training. For each such observation, a snapshot of the full 23 sensors was input to the model, which then generated an output of 23 estimates for those same sensors. A reference modeling estimation error was defined as the ratio of the average root-mean-square (RMS) of the residual (difference between the estimated and actual sensor value) to the standard deviation of the noise on the actual sensor value. When all 23 sensors were available as model input, the average estimation error was 0.271. This is a fraction of the average noise on the sensors.
The efficacy of accurately rendering virtual sensor signals is accessed by one after another sensor being randomly selected with valuea set to zero, simulating sensor failures. A maximum of 12 sensors was failed, corresponding to a loss of 52% of the originally available sensors. Estimation error as described above is shown in the following table for an increasing number of failed sensors as an average across all sensors. As would be expected, the estimation error increased as the number of failed sensors increased. However, it is notable that the estimation error across all the sensors remains comparatively low, indicating that the sensor estimates both for sensors that were not “failed” and even for sensors that were “failed” were usefully accurate.
Number of
Average RMS of
Failed Sensors
Estimation Error
0
0.2706
1
0.2763
2
0.2915
3
0.3096
4
0.3141
5
0.3237
6
0.3402
7
0.3523
8
0.3791
9
0.4014
10
0.4095
11
0.4348
12
0.4649
Turning to FIG. 11 , a chart is shown of a virtual sensor signal generated for the air conditioner after failing the original sensor and two others, and excluding them as inputs to the empirical model. Also shown is the actual value of the original sensor. The abscissa of the chart is time in minutes. The ordinate is the value of the sensor, a temperature. As can be seen, when the sensor is treated as failed (as well as two others in the set of 23), and not provided to the empirical model, the model nonetheless generates a viable and useable estimate of the sensor value, based on the other values provided as input.
It will be appreciated by those skilled in the art that modifications to the foregoing preferred embodiments may be made in various aspects. The present invention is set forth with particularity in the appended claims. It is deemed that the spirit and scope of that invention encompasses such modifications and alterations to the preferred embodiment as would be apparent to one of ordinary skill in the art and familiar with the teachings of the present application.
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An improved system and method for producing replacement sensor signals for failed sensors, and inferred sensor signals for non-instrumented physical parameters, in processes and equipment having one or more sensors in place for monitoring physical parameters. A data history from a fully-instrumented prototype provides a representative data set of anticipated operating parameters for forming an empirical model in a computer module for generating “virtual” signals for a process or machine in real-time. Replacement or inferential sensor signals can be advantageously used in downstream control processing or analysis. A memory for storing the representative training set, or a transformation thereof, is coupled to a processor. The processor receives from an input data signals embodying real values from sensors actually on the process or machine, and may receive these in real-time. The processor is disposed to take a set of readings of the actual sensors from the input, mid generate an estimate of one or more desired inferred sensors, using a linear combination of the representative training set sensor data, as weighted by the result of a measure of similarity of the input sensor data to the representative training set sensor data.
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This is a division of application Ser. No. 201,010, filed June 1, 1988, now U.S. Pat. No. 4,822,781.
BACKGROUND OF THE INVENTION
a. Field of Invention
This invention relates to novel indole derivatives, and to the processes for their preparation and use.
Notwithstanding the advances made during the last four decades in the development of agents for the treatment of inflammatory conditions and/or for analgesic purposes in conditions which require relief from pain in a mammal, there still remains a need for effective agents without the side effects associated with the therapeutic agents presently used for these purposes.
More specifically, this invention relates to tricyclic acetic acid derivatives in which the tricyclic portion thereof is characterized by having an indole portion fused to a pyrano ring. Still more specifically, the compounds of this invention are characterized as derivatives of the following tricyclic acetic acid system: ##STR1## 1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid in which the carbons at the 1-, 5-, 6-, 7-, and 8-positions are further substituted.
The indole derivatives of this invention have been found to exhibit useful pharmacodynamic properties without eliciting undesirable side effects. Notable attributes of this effect are anti-inflammatory and/or analgesic activities.
b. Prior Art
The closest prior art to the present invention is:
Demerson et al, U.S. Pat. No. 3,939,178. Demerson et al disclosed 1,3,4,9-tetrahydropyrano[3,4-b]indoles and 1,3,4,9-tetrahydrothio-pyrano[3,4-b]indoles having analgesic and anti-inflammatory activity but not with the substituents of the present invention. McKittrick et al, Canadian Patent Application No. 530,253, filed Feb. 20, 1987 corresponding to U.S. Pat. No. 4,785,015. Hughes et al, U.S. Ser. No. 876,522, filed June 19, 1986, now abandoned. Related United States Patents are U.S. Pat. Nos. 3,974,179; 3,843,681 and U.S. Ser. No. 838,510, filed Mar. 11, 1986, now U.S. Pat. No. 4,670,462.
SUMMARY OF THE INVENTION
The compounds of this invention are represented by formula (I) ##STR2## wherein R 1 is hydrogen, lower alkyl containing 1 to 4 carbon atoms or halogen; R 2 is lower alkyl containing 1 to 4 carbon atoms and the pharmaceutically acceptable salts thereof.
A preferred aspect of the present invention is the compounds represented by formula (I) wherein R 1 is hydrogen or fluorine; R 2 is methyl and the pharmaceutically acceptable salts thereof.
The most preferred compounds of the present invention are designated (Z)-1-ethyl-7-fluoro-1,3,4,9-tetrahydro-8-(1-propenyl)-pyrano[3,4-b]indole-1-acetic acid; and (Z)-1-ethyl-1,3,4,9-tetrahydro-8-(1-propenyl)-pyrano[3,4-b]indole-1-acetic acid.
The indole derivatives of this invention of formula (I) are prepared by the following process. ##STR3##
DETAILED DESCRIPTION OF THE INVENTION
The term "lower alkyl" as used herein represents straight chain alkyl radicals containing 1 to 4 carbon atoms and branched chain alkyl radicals containing three to four carbon atoms and includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl and the like.
The term "halogen" as used herein includes fluorine, chlorine, bromine and iodine.
The compounds of formula (I) form salts with suitable pharmaceutically acceptable inorganic and organic bases. These derived salts possess the same activities as the parent acid and are included within the scope of this invention. The acid of formula (I) is transformed in excellent yield into the corresponding pharmaceutically acceptable salts by neutralization of said acid with the appropriate inorganic or organic base. The salts are administered in the same manner as the parent acid compounds. Suitable inorganic bases to form these salts include, for example, the hydroxides, carbonates, bicarbonates or alkoxides of the alkali metals or alkaline earth metals, for example, sodium, potassium, magnesium, calcium and the like. The preferred salt is the sodium salt. Suitable organic bases include the following amines; lower mono-, di- and tri-alkylamines, the alkyl radicals of which contain up to three carbon atoms, such as methylamine, dimethylamine, trimethylamine, ethylamine, di- and triethylamine, methylethylamine, and the like; mono, di- and trialkanolamines, the alkanol radicals of which contain up to three carbon atoms, such as mono-, di- and triethanolamine; alkylenediamines which contain up to six carbon atoms, such as hexamethylenediamine; amino sugars, such as glucosamine; cyclic saturated or unsaturated bases containing up to six carbon atoms, such as pyrrolidine, piperidine, morpholine, piperazine and their N-alkyl and N-hydroxyalkyl derivatives, such as N-methylmorpholine and N-(2-hydroxyethyl)piperidine, as well as pyridine. The preferred salt is the 1,2-ethanediamine salt. Furthermore, there may be mentioned the corresponding quaternary salts, such as the tetraalkyl (for example tetramethyl), alkyl-alkanol (for example methyltrimethanol and trimethyl-monoethanol) and cyclic ammonium salts, for example the N-methyl-pyridinium, N-methyl-N-(2-hydroxyethyl)-morpholinium, N,N-dimethyl-morpholinium, N-methyl-N-(2-hydroxyethyl)-morpholinium, N,N-dimethyl-piperidinium salts, which are characterized by good water-solubility. In principle, however, there can be used all the ammonium salts which are physiologically compatible.
The transformations to the salts can be carried out by a variety of methods known in the art. For example, in the case of salts of inorganic bases, it is preferred to dissolve the acid of formula (I) in water containing at least one equivalent amount of a hydroxide, carbonate, or bicarbonate. Advantageously, the reaction is performed in a water-miscible organic solvent inert to the reaction conditions, for example, methanol, ethanol, dioxane, and the like in the presence of water. For example, such use of sodium hydroxide, sodium carbonate or sodium bicarbonate gives a solution of the sodium salt. Evaporation of the solution or addition of a water-miscible solvent of a more moderate polarity, for example, a lower alkanol, for instance, butanol, or a lower alkanone, for instance, ethyl methyl ketone, gives the solid salt if that form is desired.
To produce an amine salt, the acid of formula (I) is dissolved in a suitable solvent of either moderate or low polarity, for example, ethanol, acetone, ethyl acetate, diethyl ether and benzene. At least an equivalent amount of the amine corresponding to the desired cation is then added to that solution. If the resulting salt does not precipitate, it can usually be obtained in solid form by addition of a miscible diluent of low polarity, for example, benzene or petroleum ether, or by evaporation. If the amine is relatively volatile, any excess can easily be removed by evaporation. It is preferred to use substantially equivalent amounts of the less volatile amines.
Salts wherein the cation is quaternary ammonium are produced by mixing the acid of formula (I) with an equivalent amount of the corresponding quaternary ammonium hydroxide in water solution, followed by evaporation of the water.
Also included in this invention are the optical isomers of the compounds of formula (I) which result from asymmetric centers, contained therein e.g. 1-carbon. Such isomers can be obtained in substantially pure form by classical separation techniques and by stereochemically controlled syntheses.
ANTI-INFLAMMATORY ACTIVITY
The useful anti-inflammatory activities of the pyranoindole acetic acid derivatives of formula (I) are demonstrated in standard pharmacologic tests, for example, the test designated: Preventative Adjuvant Edema
The objective of this test is to determine the ability of test drugs to exhibit an acute anti-inflammatory effect in rats. This test is a primary screen for anti-inflammatory drugs.
Species:
Male Sprague Dawley rats (180-200 g) are used. The animals have free access to water but food is withdrawn 18 hours before testing.
Drug Preparations and Adminstration:
Freund's complete adjuvant is prepared by suspending 5 mg of killed and dried Mycobacterium butyricum (Difco) in 1 mL mineral oil. The test compounds are dissolved, or suspended in 0.5% Tween 80 in distilled water according to their solubility. For primary screening all drugs are administered by gastric lavage at the arbitrary dosage of 25 mg/kg, p.o. in a volume of 0.5 mL/100 g body weight to groups of 10 animals.
Methodological Details:
The method is essentially that described by Wax et al, J. Pharmacol. Exp. Ther., 192, 166-171 (1975). Groups of rats are injected intradermally in the left hind paw with 0.1 mL of Freund's complete adjuvant. The test compound or vehicle is administered immediately before the adjuvant, 24 hours and 48 hours after the adjuvant (days 0, 1 and 2). The injected hind paw volume is measured before the injection of adjuvant and 24 hrs. after the last drug administration (day 3) by means of a plethysmometer (Buxco Electronics Inc.). The difference between the hind paw volume on day 0 and day 3 represents the edema volume. Etodolac (25 mg/kg, p.o.) is included as a positive control.
Presentation of Results:
The mean edema volume (expressed as mL±SEM) is calculated for each group and the percentage protection conferred by the drug is calculated: ##EQU1## where c is the mean edema volume for the vehicle-treated (0.5% Tween 80 in distilled water) controls and t is the mean edema volume for the drug treated group.
ANALGESIC ACTIVITY
A further test used to determine the utility of the compounds of the present invention is designated: Drug Effects on Phenylbenzoquinone-induced Writhing in Mice
The objective of this test is to determine the ability of test drugs to inhibit the nociceptive (pain) response of mice injected with a chemical irritant. This test is a primary screen for both peripheral and centrally acting analgesic drugs.
Species:
Male Swiss albino mice (15-25 g). The animals are fasted for 18 hours prior to use but have free access to water.
Drug Preparation and Administration:
Drugs are dissolved or suspended according to their solubility in 0.5% Tween 80 in distilled water. They are administered by gastric gavage in a volume of 5 mL/kg. For primary screening all drugs are administered at the arbitary dosage of 25 mg/kg, p.o. to a group of 10 mice.
Methodological Details:
A modification of the method of Siegmund et al, Proc. Soc. Exp. Biol. Med., 95, 729-731 (1957) is used. Groups of 5 mice are dosed with the test compound or vehicle control. Sixty minutes later the animals are injected i.p. with 0.3 mL/20 g body weight of a 0.02% solution of phenylbenzoquinone (PBQ; 2-phenyl-1,4-benzoquinone) and placed in individual observation boxes. The number of writhing or abdominal squirming movements made by each mouse during the following 15 min. period is counted. The experiment is repeated with another group of 5 mice and the mean numbr of writhes per mouse for a group of 10 mice is calculated.
Presentation of Results:
Drug treated and vehicle-treated control groups are compared and the percentage protection conferred by the drug is calculated: ##EQU2## where c=mean number of writhes in the control group where t=mean number of writhes in the test drug group
Typical results obtained for the compounds of the present invention in the aforementioned tests are as follows:
TABLE I______________________________________Substituted 1,3,4,9-Tetrahydropyrano[3,4-b]indole-1-acetic Acids ##STR4## Preventative PhenylquinoneExample Adjuvant Edema* Writhing in Mice*______________________________________1 69(10) 32(10)2 73(25) 11(200)______________________________________ *The numbers quoted are percent inhibition at the dose in mg/kg given in parentheses. See Table II for definition of R.sup.1.
The lack of side effects associated with the compounds of this invention are demonstrated by standard acute toxicity tests as described by R. A. Turner in "Screening Methods in Pharmacology," Academic Press, New York and London, 1965, pp. 152-163, and by prolonged administration of the compound to warm-blooded animals.
When the compounds of this invention are employed as anti-inflammatory and analgesic agents in warm-blooded animals, they are administered orally, alone or in dosage forms, i.e., capsules or tablets, combined with pharmacologically acceptable excipients, such as starch, milk sugar and so forth, or they are adminstered orally in the form of solutions in suitable vehicles such as vegetable oils or water. The compounds of this invention may be administered orally in sustained release dosage form or transdermally in ointments or patches.
The compounds of this invention may also be administered in the form of suppositories.
The dosage of the compounds of formula (I) of this invention will vary with the particular compound chosen and form of administration. Furthermore, it will vary with the particular host under treatment. Generally, the compounds of this invention are administered at a concentration level that affords efficacy without any deleterious side effects. These effective anti-inflammatory and analgesic concentration levels are usually obtained within a therapeutic range of 1.0 μg to 500 mg/kg per day, with a preferred range of 1.0 μg to 100 mg/kg per day. The preferred anti-inflammatory and analgesic dose range is 20 μg to 20 mg/kg/day.
The compounds of this invention may be administered in conjunction with nonsteroidal anti-inflammatory drugs such as acetaminophen, ibuprofen and aspirin and/or with opiate analgesics such as codeine, oxycodone and morphine together with the usual doses of caffeine. When used in combination with other drugs, the dosage of the compounds of the present invention is adjusted accordingly.
The compounds of the present invention also possess antipyretic activity.
The following examples further illustrate this invention.
EXAMPLE 1
(Z)-1-Ethyl-7-fluoro-1,3,4,9-tetrahydro-8-(1-propenyl)pyrano[3,4-b]indole-1-acetic Acid, 1,2-Ethanediamine Salt
(I, R 1 =7-fluoro)
Step (1) Preparation of 2-Fluoro-6-nitrophenyl Trifluoromethanesulfonate
A mixture consisting of 2-fluoro-6-nitrophenol (20 g, 0.14 mol) and potassium carbonate (20 g, 0.14 mol) in acetone (350 mL) was stirred at room temperature for 20 minutes. A solution of trifluoromethanesulfonyl chloride (23.7 g, 0.14 mol) in acetone (100 mL) was added dropwise at room temperature. Stirring was continued for 3 hours. The reaction was filtered, and the filtrate was concentrated. The residue was dissolved in diethyl ether (300 mL), washed with 0.1N NaOH, water, dried (MgSO 4 ), filtered and evaporated to give 21.5 g of the title compound.
1 H NMR (CDCl 3 : δ 8.0 (m, 1H), 7.6 (m, 2H).
Step (2) Preparation of 2-Iodo-3-fluoronitrobenzene
A mixture consisting of 2-fluoro-6-nitrophenyl trifluoromethanesulfonate (62.0 g, 0.215 mol), lithium iodide (60 g, 0.451 mol) and 1-methyl-2-pyrrolidinone (400 mL) was heated with stirring at 130°-132° C. (oil bath temperature) for 18 hours. Upon cooling it was poured into water (1200 mL) and extracted with diethyl ether. The combined extracts were washed with 1N NaOH, water and with brine. The solution was dried (MgSO 4 ), filtered, and concentrated in vacuo to give 27.0 g of the title compound as a brown-colored solid title compound (m.p. 54°-57° C.).
1 H NMR (CDCl 3 ): δ 7.63 (d, J=8.1, 1H), 7.50 (m, 1H), 7.35 (m, 1H).
Step (3) Preparation of 2-Iodo-3-fluoroaniline Hydrochloride
A solution of 2-iodo-3-fluoronitrobenzene (27.0 g, 0.101 mol) in tetrahydrofuran (200 mL) was added dropwise over a 10 minute period to a stirring solution of stannous chloride dihydrate (68.0 g, 0.302 mol) in concentrated hydrochloric acid (200 mL). After 3 hours at room temperature the reaction was poured onto ice, made alkaline (pH 11) with 50% NaOH, and extracted with diethyl ether. The combined organic phases were washed with water, brine, dried (MgSO 4 ), filtered, and concentrated to almost dryness. Ethereal HCl was added pH 1-2), and the resulting precipitate filtered and dried to afford 25.0 g of the title compound, m.p. 197°-198° C. (dec.).
1 H NMR (DMSO-d 6 ): δ 7.09 (m, 1H), 6.6 (d, J=8.2, 1H), 6.4 (m, 1H).
Step (4) Preparation of 3-Fluoro-2-iodophenylhydrazine Hydrochloride
2-Iodo-3-fluoroaniline hydrochloride (5.7 g, 0.021 mol) was stirred in 7.4 mL of concentrated HCl and cooled to -10° C. An aqueous solution of sodium nitrite (1.63 g, 0.024 mL) in 5 mL water was added dropwise over a 20 minute period, stannous chloride (9.95 g, 0.044 mol) in 12 mL of 6N HCl added at -5° C., warmed to room temperature and stirring continued for 4 hours. The reaction mixture was cooled to 0° C., and made basic with 50% NaOH (pH 10-11), extracted with ether, washed with water, brine, dried (MgSO 4 ), filtered and concentrated to give the hydrazine. Addition of ethereal HCl (pH 1-2) gave 4.6 g of the title compound, m.p. 165°-167° C.
1 H NMR (DMSO-d 6 ): δ 10.35 (bs), 7.9 (bs), 7.4 (m, 1H), 6.88 (m, 1H), 6.78 (m, 1H).
Step (5) Preparation of 7-Iodo-6-fluorotryptophol
3-Fluoro-2-iodophenylhydrazine hydrochloride (18 g, 0.62 mol) was dissolved in 10% aqueous THF (165 mL) and a solution of dihydrofuran (5.3 g, 0.075 mol) was added at 0° C. This mixture was stirred at -10° C. to room temperature for 2 hours. Ether was added to the reaction mixture and the organic phase washed with brine. Concentration of the ether layer afforded the hydrazone (18.0 g as an amber oil). Without further purification the hydrazone was suspended in ethylene glycol and zinc chloride (15.0 g, 0.11 mol) was added. The mixture was heated to 165°-170° C. for 2.5 hours, then cooled to room temperature and extracted with ether. The ether layers were washed (brine), dried (MgSO 4 ) and concentrated to yield an oil. This was purified via flash chromatography using 1:2 EtOAc:hexane to give the tryptophol as a yellow oil (5.6 g).
1 H NMR (CDCl 3 ): δ 8.60 (bs), 7.48 (dd, J 1 =8.5, J 2 =5.0, 1H), 7.13 (d, J=2.2, 1H), 6.90 (t, J=8.7, 1H), 3.90 (t, J=6.3, 2H), 2.99 (t, J=6.3, 2H).
Step (6) Preparation of 1-Ethyl-7-fluoro-8-iodo-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid, Methyl Ester
7-Iodo-6-fluorotryptophol (5.6 g, 0.018 mol) was dissolved in CH 2 Cl 2 (400 mL). To this was added methyl 3-methoxy-2-pentenoate (3.2 g, 0.022 mol) and bromotrifluoride etherate (1.0 mL). After stirring at room temperature for 40 minutes the mixture was diluted with 10% NaHCO 3 . The CH 2 Cl 2 layer was separated and dried (MgSO 4 ) to yield 5.5 g of the pyrano[3,4-b]indole product as an oil, which solidified on standing, m.p. 109°-111° C.
1 H NMR (CDCl 3 ): δ 9.3 (bs, 1H), 7.34 (dd, J 1 =8.5, J 2 =5.0, 1H), 6.86 (t, J=8.6, 1H), 4.0-3.92 (m, 2H), 3.76 (s, 3H), 2.99 (d, J=16.6, 1H), 2.92 (d, J=16.6, 1H), 2.79-2.69 (m, 2H), 2.17-1.98 (m, 2H), 0.82 (t, J=7.3, 3H).
Step (7) Preparation of 1-Ethyl-7-fluoro-8-(1-propynyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid, Methyl Ester
A mixture of 1-ethyl-7-fluoro-8-iodo-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, methyl ester (5.2 g, 0.012 mol), copper (I) methyl acetylide (3.05 g, 29.72 mmol), and 75 mL of dry pyridine was refluxed, under a flow of nitrogen, for 6 hours. The mixture was then poured into 100 mL of 1N HCl and the aqueous solution was extracted with ether (3×100 mL). The combined extracts were washed with 1N HCl (2×100 mL) and saturated NaCl (2×100 mL), dried over magnesium sulfate, filtered and concentrated to give the crude product. This material was purified by flash chromatography (20% ethyl acetate/hexane, silica gel) to give the pure acetylenic ester (2.5 g).
1 H NMR (CDCl 3 ): δ 9.14 (bs, 1H), 7.32 (dd, J 1 =8.6, J 2 =5.0, 1H), 6.8 (dd, J 1 =8.7, J 2 =10.3, 1H), 4.04-3.91 (m, 2H), 3.73 (s, 3H), 2.99 (d, J=16.3, 1H), 2.90 (d, J=16.3, 1H), 2.78-2.68 (m, 2H), 2.23 (s, 3H), 2.2-1.98 (m, 2H), 0.82 (t, J=7.3, 3H).
Step (8) Preparation of (Z)-1-Ethyl-7-fluoro-8-(1-propenyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid, 1,2-Ethanediamine Salt
A mixture consisting of 1-ethyl-7-fluoro-8-(1-propynyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, methyl ester (2.8 g, 0.085 mol), methanol (250 mL) and Lindlar catalyst (0.5 g) was hydrogenated at atmospheric pressure. The reaction was monitored by TLC until only a trace of starting material remained. After 42 minutes the reaction was filtered, and concentrated to give 2.6 g of a thick oil. This oil was dissolved in methanol (150 mL) and 1N potassium hydroxide was added (15 mL). The mixture was refluxed for 4 hours, then cooled and acidified with concentrated 1N HCl, and the aqueous solution extracted with ether. The ether layers were washed (brine), dried (MgSO 4 ) and concentrated to give 2.2 g of a thick oil. A solution of ethylenediamine (0.416 g in 30 mL ether) was added to the oil in 30 mL of ether. Concentration gave a solid. Recrystallization of the solid from toluene afforded 1.9 g of the title compound, m.p. 156°-158° C.
EXAMPLE 2
(Z)-1-Ethyl-8-(1-propenyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid
Step (1) Preparation of 7-Iodotryptophol
To a suspension of 2-iodophenylhydrazine hydrochloride in dioxane (220 mL) and water (14 mL) was added a solution of 2,3-dihydrofuran (18.22 g, 0.26 mmol) in dioxane (20 mL). The addition took 15 minutes. The resulting yellow solution was heated at 95° C. for 3 hour at which time the solution had turned red and no starting material was detected by TLC analysis. The reaction mixture was added to ether (1.5 L) and a dark brown oil separated. The ether solution was decanted from the residue, dried (MgSO 4 ), filtered and evaporated to produce a red-brown oil (71.8 g). This material was chromatographed through silica gel (40% EtOAc/hexane) to produce a yellow oil which solidified upon standing (16.19 g), m.p. 69°-71° C.
NMR (CDCl 3 ): δ 8.25 (m, 1H), 7.60 (m, 2H), 7.00 (m, 2H), 3.90 (t, 2H), 2.95 (t, 2H), 1.85 (s, 1H).
Step (2) Preparation of 1-Ethyl-8-iodo-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid, Methyl Ester
7-Iodotryptophol (17.57 g 61.2 mmol), methyl propionylacetate (9.55 g, 73.4 mmol) and p-toluenesulfonic acid (3.3 g) were dissolved in benzene (500 mL) and refluxed in a Dean-Stark apparatus for 3 hours. The mixture was concentrated in vacuo and the resulting oil was dissolved in ether, washed with saturated NaHCO 3 (2×100 mL), dried (MgSO 4 ), filtered and evaporated to produce a brown oil (19.89 g).
Step (3) Preparation of 1-Ethyl-8-(1-propynyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid, Methyl Ester
A mixture of 1-ethyl-8-iodo-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, methyl ester (5.93 g, 14.86 mmol), copper (I) methyl acetylide (3.05 g, 29.72 mmol), and 75 mL of dry pyridine was refluxed, under a flow of nitrogen, for 6 hours. The mixture was then poured into 100 mL of 1N HCl and the aqueous solution was extracted with ether. The combined extracts were washed with 1N HCl and saturated NaCl, dried over magnesium sulfate, filtered and concentrated to give the crude product. The material was purified by flash chromatography (15% ethyl acetate/hexane, silica gel) to give the pure title compound (2.16 g).
Step (4) Preparation of (Z)-1-Ethyl-8-(1-propenyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic Acid, Methyl Ester
A mixture of 1-ethyl-8-(1-propynyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, methyl ester (155 mg, 0.5 mmol), Lindlar catalyst (15 mg), and methanol (10 mL) was charged with 1 atmosphere of hydrogen and allowed to stir at room temperature overnight. The catalyst was then removed by filtration through a celite plug, and the filtrate concentrated to give 170 mg of the crude product. This material was purified by flash chromatography (10% ethyl acetate/hexane, silica gel) to give the pure title compound as yellow oil (70 mg).
Step (5) Preparation of (Z)-1-Ethyl-8-(1-propenyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole -1-acetic Acid
(Z)-1-Ethyl-8-(1-propenyl)-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid, methyl ester (1.01 g, 3.2 mmol) was dissolved in a mixture of 11.2 mL of ethanol and 11.2 mL of 10% aqueous sodium hydroxide, and the solution was heated under reflux for 3 hours. The reaction mixture was then concentrated to dryness, and a mixture of 13.4 mL of ether and 13.4 mL of 10% aqueous sodium hydroxide was added to the residue. The layers were separated, and the aqueous layer was acidified with concentrated hydrochloric acid and extracted with ether (2×25 mL). The combined ether extracts were dried over anhydrous magnesium sulfate, filtered and concentrated to give 897 mg of the crude product. This material was purified by flash chromatography (20% ethyl acetate/hexane, H 3 PO 4 treated silica gel) to give the desired product as a colorless oil which partially solidified upon standing. Trituration with petroleum ether provided 440 mg of an off-white solid, m.p. 89.5°-93.5° C.
TABLE II______________________________________Substituted 1,3,4,9-tetrahydropyrano[3,4-b]indole-acetic Acids ##STR5##Example R.sup.1 Melting Point °C.______________________________________1 (1,2-ethanediamine salt) F 156-1582 H 89.5-93.5______________________________________
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Indole derivatives characterized by having a 1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid nucleus bearing substituents in position 1-,5-,6-, 7- and 8- are disclosed. The derivatives are useful anti-inflammatory and/or analgesic agents. Methods for their preparation and use are also disclosed.
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BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to oil and liquid separator apparatus as used at a well head for separating hydrocarbon streams from the well and composed of a mixture of gas, liquid hydrocarbons and/or free water.
2. Description of the Prior Art
Prior separators of this type may be seen in U.S. Pat. Nos. 2,610,697, 2,614,648, 2,656,896, 2,706,531, 2,910,136, 3,212,232 and 2,349,944. In each of the separators in this group of prior art patents, hydrocarbon streams composed of a mixture of gas, liquid hydrocarbons and/or free water are directed through horizontally disposed tanks with various structural arrangements therein for effecting the desired separation. Some of these patents incorporate centrifugal separators as the same are effective when the gas stream flows at a relatively high velocity.
Others incorporate various baffles and collection devices in relatively small separation areas. Such baffles and separation devices are supposed to collect droplets of distilate and/or water impinged thereagainst by the gas stream passing thereover or therethrough. In most of the prior art devices these baffles and collection devices occupy a large area which is considerably more useful if it it left open so that the turbulence of the gas stream leaving the inlet subsides and permits the heavier liquid particles therein to fall to the bottom of the tank.
The present invention introduces the gas stream and its entrained liquid into a horizontally disposed tank by way of a centrifugal separator for the primary separation of the gas liquid stream and provides an unusually large settling section downstream of the centrifugal separator of sufficient capacity to allow the turbulence of the gas stream to subside whereby the heavier liquid particles will fall therefrom. Transverse baffles positioned low in the separation area do not interfere with the gas stream, but inhibit fluid surges in the separated liquid as may otherwise occur. Finally, downstream of the settling section, novel ceramic chip and stainless steel extractors separate distilate and mist from the gas stream.
SUMMARY OF THE INVENTION
A horizontally disposed gas and liquid separator comprises an elongated horizontally disposed tank having a large intermediate section defining a settling section for a gas stream passing therethrough. The gas stream is introduced into an inlet end of the tank upstream of the settling section by way of a centrifugal separator which accomplishes the primary separation of the gas liquid stream and the settling section communicates with an outlet port through two mist extractors utilizing ceramic chips and/or stainless steel mesh. Several transverse baffles positioned low in the settling section of the separator inhibit surges as might otherwise occur in the liquid therein as a result of unusual pressure and flow rates in the gas stream being processed.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a horizontal section of the horizontal gas and liquid separator;
FIG. 2 is an enlarged vertical section on line 2--2 of FIG. 1; and
FIG. 3 is an enlarged vertical section on line 3--3 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
By referring to the drawings and FIG. 1 in particular, it will be seen that the horizontal gas and liquid separator consists of an elongated cross sectionally circular tank 10 having end closures 11 and 12 and inlet and outlet ports 13 and 14 respectively adjacent the end closures 11 and 12 respectively.
A dump valve 15 communicates with the bottom of the tank 10 midway between its ends and a drip section drain 16 communicates with the tank 10 adjacent the end closure 12 and below the outlet port 14. The inlet port 13 is connected by an L-shaped tube 17 with a centrifugal extractor having an outer cylindrical body 18 open at its upper and lower ends and an inner spaced cylindrical body 19, gas having entrained liquids is introduced under pressure through the inlet port 13 and flows through the tubular element 17 and tangentially into the outer cylindrical body 18 of the cylindrical body by way of an inlet opening 20. The gas and its entrained liquid flowing at a high velocity from a well head or the like, centrifugally separates much of the liquid which may be oil, distilate and water from the gas stream, the liquid filling approximately a third of the interior of the tank 10 as indicated by the liquid level L. The lower end of the outer cylindrical body 18 of the centrifugal separator is positioned below the liquid level L so that the gas after passing through the cylindrical separator flows upwardly and outwardly thereof as indicated by the arrows and over a tall baffle 21 positioned transversely of the tank 10 and providing spaces above and below the upper and lower edges of the baffle respectively. The gas then flows through a settling section 22 which is substantially larger than settling sections in the prior art and is relatively free of objects which would interfere with the gas stream or create turbulence therein.
A series of low transverse baffles 23 are positioned in spaced longitudinal relation transversely of the tank 10 in the settling section 22. A secondary tall baffle 24 is positioned downstream of the settling section 22 transversely of the tank 10 with its lower edge below the liquid level L and its upper edge spaced with respect to the upper portion of the tank 10 to form a gas passageway. A third baffle 25 is positioned downstream with respect to the tall baffle 24 transversely of the tank 10 and in sealing relation with the upper portion thereof, a screen 26 forms a transverse support for a plurality of ceramic chips 27 or the like positioned on the screen and forming a mist extractor. An angular baffle 28 is positioned above the liquid level L and below the screen 26.
A transverse partition 29 is positioned transversely of the tank 10 downstream from the secondary tall baffle 24 and the baffle 25 and spaced with respect to a secondary transverse baffle 30 closed with respect to the upper portion of the tank 10. A screen 31 is positioned between the baffle 29 and the baffle 30 and a layer of steel mesh 32 is carried on the screen, the device forming a secondary extractor particularly adapted to separate condensate remaining in the gas stream therefrom. An angular baffle 33 is disposed below the screen 31 and it will be observed that the condensate separated from the gas stream will fall into the lower portion of the tank 10 between the tall baffle 29 and the end closure 12 where it may be removed by the drip drain 16 heretofore referred to.
In FIG. 1 of the drawings arrows show the gas flow through the device and outwardly of the outlet port 14.
The tank 10 is shown supported on standards 34 which in turn may be mounted on skids 35 and the skids 35 may also support a tank 36 which may be used as a heater for the horizontal gas and liquid separator.
By referring now to FIG. 2 of the drawings an enlarged vertical section on line 2--2 of FIG. 1 may be seen with the inlet port 13 communicating with the L-shaped tubular connection 17 by which the inlet gas is tangentially directed through the opening 20 into the centrifugal separator and specifically the outer cylinder body 18 thereof.
In FIG. 2 of the drawings, a spider 37 will be seen to be positioned with its arms engaged on the outer cylindrical body 18 and the inner cylindrical body 19 and supporting the same in spaced relation.
In FIG. 3 of the drawings, the baffle 25 will be seen to form a transverse closure with respect to the downstream end of the settling section 22 of the horizontal gas and liquid separator with the screen 26 and its structural support extending transversely of the tank 10 between the side walls thereof. This structure restricts the gas flow.
By again referring to FIG. 1 of the drawings, it will be seen that the screen 26 and its structural support are also supported by the secondary tall baffle 24 and the third baffle 25. The arrangement is such that a restricted open transverse area in the upper portion of the tank 10 permits the gas stream flowing through the horizontal gas and liquid separator to engage a substantially large area of the primary ceramic mist extractor including the chips 27. The mist extracted by the primary mist extractor is usually largely water and oil and it is collected along with the other liquid in the main portion of the tank 10 and indicated by the letter L as heretofore described.
Still referring to FIG. 1 of the drawings, it will be observed that the lighter liquid mists which are usually condensate are thus not separated from the heavier mists and are in turn subjected to the secondary extractor including stainless steel mesh or the like as indicated at 32 in FIG. 1 of the drawings. It will be understood that the configuration of the secondary extractor is the same as the primary extractor with the exception that stainless steel mesh is substituted for the ceramic chips. The condensate is thus separated from the gas just before it reaches the outlet port 14 and the condensate forms a pool in the bottom of the tank 10 downstream of the tall baffle 39 which closes the middle and lower portion of the interior of the tank 10 with respect to the settling section 10. The gas stream is therefore forced to flow through the settling section where turbulence ends, the heavier liquids drop out and then over the secondary tall baffle 29 down through the primary ceramic mist extractor and the ceramic chips or bodies 27 therein and then upwardly over the tall baffle 29 which forms a partition across all of the interior of the tank 10 except the uppermost portion thereof and flows downwardly through the secondary extractor and the stainless steel mesh 32 therein.
The arrangement is such that the gas stream is very effectively separated from the water, oil and distilate or condensate normally found in gas streams at the well head or the like. The restricted gas flow through the mist extractors results in a pressure drop across the extractor material 27 and 32 causes them to operate at a lower temperature than that of the gas stream thus enhancing the coalescent and extraction properties of the device.
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A device for separating mixtures of gas, liquid hydrocarbons and/or free water provides an elongated horizontally disposed tank with a centrifugal separation device at its inlet end and a substantially large open separating section downstream thereof followed by a mist extractor and a condensate extractor which pass the gas stream through ceramic chips and/or stainless steel mesh as a final separation of liquid droplets from the gas stream.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of non-provisional U.S. application Ser. No. 10/709,133, filed Apr. 15, 2004, now U.S. Pat. No. 6,913,965 now allowed.
BACKGROUND OF INVENTION
1. Field of the Invention
The invention relates generally to semiconductors and, more particularly, to metal-insulator-metal (MIM) capacitors for integrated circuits.
2. Background of the Invention
The integration of MIM capacitors and field effect transistors (FETs) on an integrated circuit are important because analog circuits usually require precision capacitors as well as transistors. The on-chip integration of MIM capacitors, FETs, and other devices reduces the cost associated with fabricating integrated circuits.
Semiconductor capacitors are prone to dielectric damage during fabrication that lead to reliability fails due to dielectric breakdown. For example, a MIM capacitor can have a reliability sensitivity to the etch of the inter-level dielectric (ILD) for the vias used to contact the top plate of the MIM capacitor. The integration of high performance inductors with MIM capacitors on a semiconductor chip is done in part with relatively large, tall vias in the inter-level dielectric above the MIM capacitor, which results in prolonged exposure of the MIM capacitor to the via etch.
To reduce the exposure of the top plate to the prolonged via etch, an insulator layer such as, for example, silicon nitride, is formed covering the entire substrate including the top plate of the capacitor and the inter-level dielectric. Referring to FIG. 1 , a substrate 10 is provided upon which front-end-of-line (FEOL) levels 20 including semiconductor structures such as, for example, FETs (not shown) and inter-level dielectric layer 25 are formed. Back-end-of-line levels 30 are subsequently formed upon the FEOL levels 20 , and include semiconductor structures such as, for example, interconnect 35 and MIM capacitor 40 . Conventionally, MIM capacitor 40 is formed on inter-level dielectric layer 25 by depositing a bottom metal layer 45 , a portion of which forms a bottom metal plate of the MIM capacitor and another portion of which forms an electrical contact area, depositing a dielectric layer 50 on the bottom metal layer 45 , and depositing on the dielectric layer 50 a top metal layer 55 , a portion of which forms a top metal plate of the MIM capacitor and another portion of which forms an electrical contact area. Over the MIM capacitor, an insulator layer 60 is deposited to cover inter-level dielectric 25 , interconnect 35 and MIM capacitor 40 . Processing continues with a deposition to form inter-level dielectric 65 and a reactive ion etch to form via 70 . The insulator layer 60 acts as an etch stop for the MIM capacitor top plate 55 to prevent exposure to the via etch, thus preventing breakdown of the MIM capacitor dielectric.
Although reliability of the capacitor dielectric is improved in conventional MIM capacitor fabrication, it has been observed that the performance of FETs formed on FEOL levels 20 below the insulator layer 60 are degraded. The formation of a MIM capacitor with reduced sensitivity to dielectric damage without degrading the performance of FETs is desired.
SUMMARY OF INVENTION
It is thus an object of the present invention to provide MIM capacitors with reduced sensitivity to dielectric damage without degrading the performance of FETs in an integrated circuit.
The foregoing and other objects of the invention are realized, in a first aspect, by a semiconductor structure comprising:
a substrate comprising a plurality of levels formed thereupon;
a metal-insulator-metal (MIM) capacitor formed on an inter-level dielectric layerin a first of the plurality of levels; and
an insulator layer selectively formed on said MIM capacitor, wherein portions of the inter-level dielectric layer are insulator layer-free.
Another aspect of the invention is a method of forming a semiconductor structure comprising the steps of:
providing a substrate comprising a plurality of levels formed thereupon;
forming a metal-insulator-metal (MIM) capacitor on an inter-level dielectric layer in a first of the plurality of levels; and
selectively forming an insulator layer on said MIM capacitor, wherein portions of the inter-level dielectric layer are insulator layer-free.
A further aspect of the invention is an integrated circuit comprising:
a substrate comprising a lower level including a plurality of field effect transistors and an upper level;
a metal-insulator-metal (MIM) capacitor formed on an inter-level dielectric layer in the upper level; and
a silicon nitride layer selectively encapsulating a portion of the MIM capacitor, wherein portions of the inter-level dielectric layer are silicon nitride layer-free, said silicon nitride layer-free portions allow hydrogen and/or deuterium to diffuse to the FETs.
BRIEF DESCRIPTION OF DRAWINGS
The foregoing and other features of the invention will become more apparent upon review of the detailed description of the invention as rendered below. In the description to follow, reference will be made to the several figures of the accompanying Drawing, in which:
FIG. 1 illustrates a conventional MIM capacitor.
FIGS. 2A-E show a MIM capacitor formed according to an embodiment of the invention.
DETAILED DESCRIPTION
With the integration of MIM capacitors and FETs on integrated circuit chips, MIM capacitor processing is typically performed in BEOL levels subsequent to FET processing in FEOL levels and, as such, the effect of MIM capacitor processing is not expected to have an effect on FET performance. The inventors have observed that when MIM capacitors and FETs are formed by conventional means such as was described with reference to FIG. 1 , the performance of the FETs degraded. For example, it was observed that an increase in threshold voltage shift over time occurred in FETs which were integrated with MIM capacitors in an integrated circuit.
It was determined that the shift in threshold voltage was related to the out-diffusion of hydrogen or deuterium from the channel regions of the FETs when MIM capacitors and FETs are formed in an integrated circuit chip. Without the integration of MIM capacitors, FETs formed in FEOL levels are exposed to subsequent processing steps such as, for example, a high temperature anneal in a BEOL level which results in hydrogen or deuterium diffusing through inter-level dielectrics to the FETs. Hydrogen or deuterium which diffuses out of the channel regions of the FETs is replaced by hydrogen or deuterium supplied from the ambient atmosphere (i.e. high temperature anneal). Thus, threshold voltage shifts are avoided since the channel regions of the FETs are not depleted of hydrogen or deuterium.
For MIM capacitors formed according to conventional techniques as described with reference to FIG. 1 , it has been determined that the etch stop layer (i.e. insulator layer 60 ) has an effect on the diffusion of hydrogen or deuterium from the ambient atmosphere to the FETs. For example, it has been determined that silicon nitride etch stop layer 60 formed over the entire substrate is a barrier to ambient hydrogen or deuterium diffusion during subsequent anneals. Hydrogen or deuterium is not able to diffuse from the ambient atmosphere to the channel regions of the FETs to replace hydrogen or deuterium which diffuses out of the FET channel regions. The out-diffusion of hydrogen or deuterium causes a loss of passivation in the channel regions, leading to an increase in threshold voltage shift over time due to hot-electron effects.
The invention relates to forming MIM capacitors on BEOL levels without degrading the performance of FETs formed on FEOL levels by providing a path for diffusion of hydrogen and/or deuterium from the BEOL levels to the FETs. This is accomplished by selective formation of an insulator layer on the MIM capacitors. A portion of the insulator layer is selectively removed from an inter-level dielectric layer such that ambient hydrogen and/or deuterium may diffuse to the FETs while another portion of the insulator layer remains on the MIM capacitors to prevent damage to the capacitor dielectric caused by etch processes.
Referring to FIG. 2A , a substrate 100 is provided upon which FEOL levels 105 are formed by methods known to those skilled in the art. Substrate 100 can be selected from materials such as, for example, silicon or silicon-on-insulator (SOI). FEOL levels 105 comprise semiconductor structures such as, for example, FETs, interconnects and isolation regions (not shown). BEOL levels 110 are subsequently formed upon the FEOL levels 105 , and include semiconductor structures such as, for example, inter-level dielectric (ILD) layer 115 , and interconnects and MIM capacitors (described hereinafter with reference to FIG. 2B ). ILD layer 115 can be formed of known a dielectric material such as, for example, silicon oxide or a low-k dielectric such as SILK (available from Dow Chemical Co., Midland, Mich.).
FIGS. 2B-E show the formation of a MIM capacitor according to the invention. FIG. 2B shows a lower metal layer 120 such as, for example, a layer of aluminum is formed on ILD layer 115 by methods known in the art such as, for example, chemical vapor deposition or physical vapor deposition. Aluminum layer 120 is subsequently patterned and etched as described hereinafter to provide the bottom plate of a MIM capacitor and interconnects. A capacitor dielectric 125 such as, for example, silicon oxide or silicon nitride is formed on aluminum layer 120 . A top metal plate 130 such as, for example, titanium nitride (TiN) is formed on the capacitor dielectric 125 . The capacitor dielectric 125 and the top metal plate 130 are defined using, for example, known photolithographic and etch processes.
An insulator layer 135 is then formed as shown in FIG. 2C using a known process such as, for example, chemical vapor deposition, sputter deposition or physical vapor deposition. Insulator layer 135 comprises a material which has a lower etch rate than ILD layer 115 during a subsequent via etch process. For example, when an oxide ILD layer 115 is utilized, a preferred material for use as insulator layer 135 is silicon nitride.
Referring to FIG. 2D , a photoresist layer 140 is patterned using known photolithographic processes. Exposed portions of aluminum layer 120 and silicon nitride layer 135 are removed by known etch processes such as, for example, a reactive ion etching to form the bottom plate 145 of MIM capacitor 150 and interconnects 155 as shown in FIG. 2E . Silicon nitride layer 135 encapsulates a portion of MIM capacitor 150 including capacitor dielectric 125 and top metal plate 130 , and also remains on the upper surface of the interconnects 155 , which is of no consequence. However, the silicon nitride layer 135 is removed from all other regions of the substrate resulting in openings 160 which are permeable to hydrogen and/or deuterium diffusion. Processing continues with a subsequent inter-level dielectric deposition and formation of via studs in the ILD level (not shown). The silicon nitride layer 135 acts as an etch stop for the top metal plate 130 to prevent exposure of the top metal plate 130 to the via etch.
By selectively forming openings 160 during MIM capacitor 150 processing in the BEOL levels 110 according to the invention, ambient hydrogen and/or deuterium can diffuse through diffusion paths 165 to FETs formed on FEOL levels 105 , and the silicon nitride layer 135 remains on the top plate 130 of the MIM capacitors 150 to prevent damage to capacitor dielectric 125 due to etch processes which are exposed to MIM capacitors 150 .
For integrated circuit design rules that limit the maximum metal density to, for example, about 70%, at least about 30% of the substrate would include openings 160 which would be permeable to hydrogen and/or deuterium diffusion. The inventors have observed that the performance of FETs improved by incorporating openings 160 in integrated circuits including MIM capacitors and FETs. The invention provides reliable MIM capacitors without degrading the performance of FETs.
While the invention has been described above with reference to the preferred embodiments thereof, it is to be understood that the spirit and scope of the invention is not limited thereby. Rather, various modifications may be made to the invention as described above without departing from the overall scope of the invention as described above and as set forth in the several claims appended hereto.
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The present invention relates to metal-insulator-metal (MIM) capacitors and field effect transistors (FETs) formed on a semiconductor substrate. The FETs are formed in Front End of Line (FEOL) levels below the MIM capacitors which are formed in upper Back End of Line (BEOL) levels. An insulator layer is selectively formed to encapsulate at least a top plate of the MIM capacitor to protect the MIM capacitor from damage due to process steps such as, for example, reactive ion etching. By selective formation of the insulator layer on the MIM capacitor, openings in the inter-level dielectric layers are provided so that hydrogen and/or deuterium diffusion to the FETs can occur.
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FIELD OF USE
The invention relates to a lightweight, portable handwork stitching aid, to be used for crafts wherein it is desirable to stitch in rows or sections onto an elevated canvas.
BACKGROUND
Rug making is an older art form that has recently been the subject of renewed interest even though the work involved is tedious and time consuming. However, the rugs produced are appealing to the observer, when various colored strands are used to form attractive designs or pictures. In recent years improved needles and hooks, the availability of a wide variety of pre-marked canvases, and the availability of pre-cut and pre-packaged yarns have helped to rekindle interest.
A number of frames and stands have been patented and marketed. Some of these devices have met with marginal commercial acceptance because of several design problems. These devices are generally heavy and bulky, do not fit onto the operator's lap, require the operator to sit upright either at a table or in a position surrounded by the device, and the devices are not readily adjustable.
It is the principal object of the subject invention to overcome the drawbacks of the prior art and to provide a canvas support apparatus that will hold securely the canvas at a height and angle that the operator can readily adjust.
Another object of the invention is to mount and elevate the canvas for use on the operator's lap at an inclined angle so that the hook or needle can easily pass through the canvas holes.
Another object of the invention is to allow for easy stitching of the first row and last row on either edge of the canvas within the frame.
Another object of the invention is to design a relatively simple and easy to use device that will securely hold the canvas during stitching, the device being light-weight and portable.
Other objects of the invention will become obvious to those persons familiar with these stitching crafts upon reading the following descriptions and specifications.
SUMMARY OF THE INVENTION
The invention as herein disclosed is a unique canvas support apparatus that is lightweight and portable and can be used on the operator's lap or on a table. The lap-sized apparatus holds the canvas in place for handwork stitching crafts, such as latch hooking and needlepoint and the like, where it is desirable to stitch in rows or sections onto an elevated canvas. The apparatus is easily adjusted so that the height and angle of the canvas can be positioned for operator comfort. The apparatus elevates the work area of the canvas for the convenience of the operator with clearance behind the work area, requiring minimum use of one of the operator's hands. This feature is important for older people with limited finger dexterity and handicapped people who have little use of one hand.
The rack is often small relative to the canvas requiring the canvas to be subdivided into sections. As each section of the canvas is completed, the canvas is relocated relative to the rack, so that a new section can be stitched. Also, several operators can work simultaneously on the same large canvas, one rack per each operator.
A number of means may be used to mount the canvas over the rack unit so that the strand is stitched into the canvas over a substantially open area in the rack unit. One method involves a plurality of upward projecting points that are a part of the rack unit along the perimeter of the inclined rack assembly. The canvas rests on the rack assembly and the points are individually fitted carefully through the holes in the canvas so as not to damage the canvas while the canvas is flat on the rack. Another mounting means involves an anchor member having a plurality of downward projecting points that pass through the canvas material and attach to the rack assembly. The anchor member rests on the canvas which rests on the rack assembly and the downward projecting points of the anchor member are individually fitted through the holes in the canvas. The points may be pins or prongs. Other mounting means may include clamps, scroll type rollers, or the like located around the edges of the rack assembly, where the canvas is securely held in place relative to the rack assembly.
The rack unit also has a base which is preferably a solid material, so that strands, needles, hooks, and the like can be kept therein. The base is substantially flat so that it can rest in a stable manner on the operator's lap or on a table. The underside of the base can be rough or coated with a tacky material so that it will not slip and slide when resting on the operator's lap.
The base and the rack assembly can be of single piece construction or the pieces can be separately made so that they fit together. The base is preferably made of a plastic material similar to dish drainer bases, but can also be made of wood, metal, plexiglass or similar materials. The rack assembly is preferably made from rubber coated metal, or molded plastic but can also be made from wood, metal or the like.
When not in use the rack unit is collapsible, conveniently fitting into the base tray with the anchor members, strands, hooks, needles, canvas for easy storage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an operator demonstrating the apparatus for latch hooking and similar stitches, and includes Detail "A" which depicts the canvas fitting onto the apparatus.
FIG. 2 is an assembly of the apparatus as used in latch hooking (same position as FIG. 1), including isometric views of the base, the frame portion, and the pronged anchor. The drawing also includes Detail "B" of the hinge, the Detail "C" of the base groove.
FIG. 3 is a perspective view of an operator demonstrating the apparatus for needlepoint, and similar stitches and includes Detail "D" which depicts the canvas fitting onto the apparatus.
FIG. 4 is an assembly of the apparatus as used in needlepoint (same position as FIG. 3), including isometric views of the base, the frame portion, and the frame anchor.
DETAILED DESCRIPTION
All four drawings depict the same preferred embodiment; that is, a combination rack unit that has two separate work areas and two separated mounting means.
FIG. 1 and FIG. 2 show the apparatus as it is used for latch hooking whereas FIG. 3 and FIG. 4 show the apparatus as it is used for needlepoint. The combination rack unit is considered to be the preferred embodiment since the apparatus can be used for both needlepoint and latch hooking, two types of stitching that are completely different from each other.
The position shown in FIG. 3 and FIG. 4 can be used for latch hooking but does not work as well for latch hooking as the FIG. 1 and FIG. 2 position. The position shown in FIG. 3 and FIG. 4 can also be used with a burlap canvas to make hooked rugs with hand hooks or punch needles, but to avoid confusion in this specification, the FIG. 3 and FIG. 4 position of the subject invention will be referred to as the needlepoint position.
The latch hook drawings (FIG. 1 and FIG. 2) differ from the needlepoint drawings (FIG. 3 and FIG. 4) in two ways: first, a completely different anchor is used, and second, the frame portion 30 must be inverted.
For latch hooking (FIG. 1 and FIG. 2) a canvas 11 is mounted securely over the apparatus, the apparatus having an inverted "V" section 36 which is substantially open and is the work area for latch hooking. The work area is elevated relative to a base 14. An operator 10 inserts a latch hook 13 holding the strand through the canvas 11 over the open area and then pulls the strand ends to tighten a knot about the canvas. The same reference numbers show the same parts in all drawings.
For needlepoint (FIG. 3 and FIG. 4) the canvas 11 is mounted securely and stretched over the apparatus, the apparatus having an open area inside an octagon frame 34 which is the work area for needlepoint. The work area is also elevated relative to the base 14.
It is not necessary for the subject invention to be a combination rack unit as shown in these drawings. It would be relatively easy to design a frame portion for either latch hooking or needlepoint using the principles of this disclosure that will fit securely into the base 14 and be adjustable.
FIG. 1 illustrates a preferred embodiment of the subject invention as it is used for latch hook type stitching onto a canvas.
The operator 10 is seated in an upright position with a rack unit 12 (the subject invention) resting comfortably on her lap. The rack unit 12 consists of a flat, rectangular base 14; an elevated inclined rack support 16, a rack leg 18 and a pronged anchor 20. These four components operate together to securely mount the canvas 11 (as shown in Detail "A" of FIG. 1) and hold it in place relative to the rack unit 12. The canvas 11 rests on the rack unit 12, the canvas 11 being held in place by the pronged anchor 20, which fits through the holes in the canvas 11 and attaches to the rack support 16.
The frame portion 30 is bent downward at the latch hooking work area, where it supports the canvas 11. The operator 10 uses a latch hook 13 containing one piece of strand (not shown). The operator 10 places a looped strand on the latch hook 13, and inserts the hook 13 into the aligned two holes in the canvas 11 from above the canvas 11, and by means of the hook 13 she pulls the strand ends through the holes and pulls down the sufficient pressure to knot the strand into the canvas 11.
FIG. 2 is an assembly drawing of the rack unit 12 in the latch hook mode, as shown in FIG. 1. The drawing depicts individual isometric views of the base 14, the frame portion 30, and the pronged anchor 20, with dashed lines indicating how these components fit together.
The base 14 is lap-sized, having a rectangular shape and a recessed, flat bottom 22. The underside (not shown) of the base 14 has either a rough surface, or is coated with a tacky substance to prevent slipping and sliding. The base 14 has a raised frame 24 that surrounds the bottom 22, together forming a convenient place for storing racks, anchors, hooks, needles, strands, and canvas when not in use. Two opposed sides of the raised frame 24 are grooved frame sections 26, having a plurality of inverted "T" shaped grooves 28 therein that do not extend to the recessed bottom 22 (see Detail "B" in FIG. 2). These grooves 28 allow the frame portion 30 to be adjustable, being able to be mounted in any one of several positions so that the height and angle of the work area easily adjusts for operator convenience.
The frame portion 30 consists of a rack support 16 and a rack leg 18 which are connected together by two rounded leg hinges 32 (see Detail "C" in FIG. 2) each being located at the end of each rack leg 18. The rack leg 18 consists of two identical, and parallel hinge bars 17, each having one rounded end that serves as the leg hinge 32. The leg hinges 32 are connected together at the ends opposite the hinges 32, by a leg bar 19 that protrudes beyond the two hinge bars 17, the protrusions fitting into the grooves 28 of the base 14.
The rack support 16 is an irregularly shaped, flat piece, the end section of which is bent at a right angle. One end of the rack support 16 is an inverted "V" section 36 that is used for latch hooking. The other end of the rack support 16 is an octagon frame 34 used for needlepoint. The section 36 and the frame 34 are joined by two parallel connecting rods 38 that each form part of the outline of the rack support 16.
There are three identical, parallel rods that run across the width of the rack support 16, which are perpendicular to the connecting rods 38, and are mounted onto the rack support 16 so as to protrude equally at both ends. The protrusions of these rods connect to the base grooves 28 and to the leg hinges 32 so that the rack unit 12 can be easily disassembled and reassembled by the operator 10. The octagon rod 40 is located at one extreme of the rack support 16, forming one end of the octagon frame 34. The middle rod 42 is located within the body of the rack support 16, forming one end of the latch hook work area. The end rod 44 is located at the other extreme of the rack support 16, forming the other end of the latch hook work area.
When the frame portion 30 is used for latch hooking, the octagon rod 40 of the rack support 16 fits into two opposed grooves 28 of the base 14, whereas the middle rod 42 is mounted inside the leg hinges 32 of the hinge bar 17. The leg hinges 32 can be mounted onto the end rod 44 to allow more adjustability of the height and angle of the work area. The inverted "V" section 36 is elevated relative to the base 14 and is the most remote part of the rack unit 12 from the base 14. A plurality of parallel inverted "V" rods 50 fit between and are perpendicular to the middle rod 42 and the end rod 44, and together form the inverted "V" section 36, which is the work area for latch hooking the canvas 11. The pronged anchor 20 is used in the latch hooking mode to secure the canvas 11 to the rack unit 12, although a plurality of upward projecting pins mounted along the perimeter of the rack support 16 could also be used. The pronged anchor 20 has a curved anchor body 52, which can serve as a convenient place to rest the latch hook 13 while the operator 10 is resting. The pronged anchor 20 has a plurality of identical curved prongs 54 which are used to fit through the holes in the canvas as the anchor 20 rests on the canvas 11 which rests on the rack unit 12. The prongs 54 fit under and around the middle rod 42 to hold the sandwiched canvas 11 securely in place. For latch hooking, it is not necessary to hold the canvas 11 taut or stretched, but rather it is only necessary to hold the canvas secure in place relative to the rack unit 12, as the operator tightens strand knots.
FIG. 3 illustrates the preferred embodiment of the subject invention as it is to be used for needlepoint.
The operator 10 is seated in an upright position with the inverted rack unit 12 on her lap. The rack unit 12, as used in this position, consists of the base 14, the inverted rack support 16, a rack leg 18, and a frame anchor 56. To convert the rack unit 12 into this position from the position shown in FIG. 1 and FIG. 2, the pronged anchor 20 and the canvas 11 are removed, frame portion 30 is removed from the base 14, and the rack leg 18 is removed from the rack support 16. The rack leg 18 is reattached to the rack support 16, along both ends of the octagon rod 40. The end rod 44 and the leg bar 19 are each inserted into two grooves 28 of the base. To allow for more adjustability of the height and angle of the work area for needlepoint, the leg bar 19 can be doubled back and form an obtuse angle with the plane of the base as it fits into two grooves 28 or it can form an acute angle with the plane of the base.
FIG. 4 is an assembly drawing of the rack unit 12 in the needlepoint mode, as shown in FIG. 3. The drawing depicts individual isometric views of the base 14, the frame portion 30 and the frame anchor 56 with dashed lines indicating how these components fit together. The work area for needlepoint is the opening inside the octagon frame 34, which is elevated relative to the base 14 and may be inclined relative to the base 14 (See Detail "D" in FIG. 3). The octagon frame 34 is used to hold the canvas 11 secure relative to the rack unit 12. It is important in needlepoint work that the canvas 11 be held taut and stretched during stitching, which is the reason for having two separate work areas on the rack unit. The operator 10 attaches the strand to a needle 15 used in needlepoint, the needle 15 and strand are then placed through the top of a hole in the stretched canvas 11 and reinserted through the bottom of an adjacent hole (see Detail "D") as mounting means to hold the canvas 11 onto the rack unit 12 a plurality of upward projecting pins mounted around the perimeter of the frame portion 30 could again be used. However, the drawings show a frame anchor 56 which rests on the canvas 11 that rests on the rack unit 12, the anchor 56 having four downward projecting pins 58 that fit through holes in the stretched canvas 11, into four pin holes 46 in the octagon frame 34, being held in place by pin tacks 48, one for each frame pin 58. The frame anchor 56 fastens at an angle across each corner to hold the canvas 11 without distorting the canvas corners.
For storage, the rack unit 12 is disassembled into its individual components which are folded up and stored in the base 14 along with the canvas 11, strands, needles 15, latch hooks 13 and other related materials.
Although the present invention has been specifically disclosed with preferred embodiments, many other forms of the invention are possible. It is not intended herein to mention all possible forms of the invention and the terms used are descriptive rather than limiting. Accordingly, the scope of this invention is intended to be limited only by the scope of the appended claims.
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A canvas support frame for handiwork stitching crafts such as latch hooking, or needlepoint. The frame can fit either onto the operator's lap or onto a table. A canvas is mounted onto the frame whereby the height and the angle of the material can be adjusted by the operator for comfort and easy use. The frame is lightweight and portable, and when not in use, can be closed for easy storage.
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[0001] This application claims priority from U.S. provisional application No. 60/379,305 filed on 9 May 2002 and from U.S. provisional application No. 60/379,556, filed on 9 May 2002, the contents of which are hereby incorporated by reference.
[0002] This invention relates to analogues of the amino acid L-arginine, and their use in therapy in the treatment of human disease, in particular their use for treatment of cardiovascular disease. The compounds of the invention have the ability to modulate, and preferably to enhance, the transport of the amino acid L-arginine into cells.
BACKGROUND OF THE INVENTION
[0003] All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or in any other country.
[0004] Cardiovascular diseases are well-recognised as the leading cause of death in the western world. These conditions include atherosclerosis, diabetes, hypertension, peripheral vascular disease, coronary artery disease, myocardial infarction, congestive heart failure, and cerebrovascular disease. Some of these conditions, in particular atherosclerosis and Type II diabetes, have been associated with lifestyle factors such as diet and lack of physical exercise. Cardiovascular conditions are one of the most common sequelae of both Type I and Type II diabetes. However, while lifestyle changes can significantly reduce the risk of cardiovascular diseases or can slow their development, not all patients are able to comply with strict dietary and/or exercise regimens. Moreover, some patients have a genetic predisposition to development of cardiovascular conditions. Consequently there is a great need in the art for pharmaceutical agents which can influence the underlying pathological mechanisms of development of these conditions, and/or relieve their symptoms.
[0005] For example, a wide variety of drugs is available for treatment of hypertension, and many of these are also used in the treatment of congestive heart disease and heart failure. However, few agents have been specifically developed for the treatment of heart failure alone.
[0006] It is estimated that chronic or congestive heart failure affects approximately 5,000,000 people in the United States alone, ie. approximately 2% of the population, with approximately 400,000 new cases being diagnosed each year. Hospital and out-patient management costs are responsible for approximately 2.5% of the total health care costs, and congestive heart failure is one of the single most common causes of death in industrialised societies. Current treatments for congestive heart failure are very poor, and no satisfactory agents are available. Thus currently the primary aim of treatment is to prevent progression of the condition. However, in most cases patients have to utilise multiple pharmaceutical agents, and if the condition is not controlled the only treatments available are heart transplant or external cardiac assists. Although heart transplantation can be very successful, only very few patients can be treated because of the acute shortage of donors and the requirement for histocompatibility. External cardiac assists are suitable only for short-term use.
[0007] One of the major processes associated with the development of cardiovascular diseases is a disturbance of the functional properties of the endothelium, ie. the lining layer of blood vessels. The vascular endothelium plays a pivotal role in regulating blood flow by releasing, at the appropriate time, a chemical called nitric oxide. This process is illustrated schematically in FIG. 1 . Nitric oxide (NO) is a small molecule which diffuses readily and plays a major role in vascular relaxation.
[0008] NO is generated by a family of cellular enzymes, nitric oxide synthases (NOS), which make use of the amino acid L-arginine. All isoforms of NOS catalyze a five-electron oxidation of one of two guanidino nitrogen atoms in L-arginine to yield nitric oxide and L-citrulline, as shown in FIG. 1 .
[0009] The reaction involves two monooxygenation reactions, with N-γ-hydroxy-L-arginine as an intermediate product. The reaction requires several redox cofactors, including reduced nicotinamide adenine dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin adenine mononucleotide (FMN) and tetrahydrobiopterin (THB4). It is known that the rate of production of NO is largely dependent upon the supply of L-arginine, and that supplementation with larger doses of L-arginine, per se, can improve endothelial function.
[0010] The clinical features of congestive heart failure (CHF) result from a complex interaction between reduced ventricular function, neurohormonal activation, and impaired endothelial function. While endothelial dysfunction has been well documented, the mechanisms which contribute to this dysfunction remained unclear until very recently. Possible such mechanisms included reduced expression of muscarinic cholinergic receptors on endothelial cells, altered intracellular signalling, reduced NO production, increased NO degradation, or an attenuated response by the intracellular targets of NO or cyclic GMP. Supplementation with oral or intravenous L-arginine has been shown to improve endothelial function in some conditions which are characterised by endothelial dysfunction, most notably atherosclerosis (Lerman et al 1998; Creager et al., 1992; Girerd et al., 1990). Such supplements have been shown to improve endothelial function in patients with heart failure (Hirooka et al., 1994; Rector et al, 1996), and we have shown that transport of L-arginine is impaired in patients with congestive heart failure; this could lead to a relative deficiency of intracellular arginine, thereby reducing NO synthesis (Kaye et al., 2000).
[0011] While in principle supplementation with L-arginine will have a beneficial effect, this approach suffers from the serious disadvantage that the doses required are extremely high, leading to toxic side effects as a result of the concomitant increase in urea levels. Thus there is a need in the art for alternative agents which are able to modulate L-arginine transport, without adversely affecting circulating urea levels. While supplementation with L-arginine does improve vasodilation, the doses of L-arginine which are required are very large, and result in potentially dangerous increases in blood urea levels. Thus an alternative method is needed.
[0012] Lowering intracellular L-arginine levels by inhibiting L-arginine transport has potential in the treatment of conditions in which the L-arginine-nitric oxide pathway is excessively active. These include sepsis resulting from infection, in which the NO pathway, particularly the pathway involving the inducible form of NOS (iNOS), or possibly L-arginine transport, is overactive; inflammation caused by non-infective disease states, including but not limited to arthritis, and chronic liver disease with its attendant toxaemia.
SUMMARY OF THE INVENTION
[0013] In the present specification we describe a new class of compounds, designed to modulate the ability of blood vessels to synthesize NO from L-arginine.
[0014] Without wishing to be bound by any proposed mechanism, we believe that the compounds of the invention modulate the synthesis of NO, presumably by up or down-regulating the transport of L-arginine, which is a substrate for NOS. In particular we have identified novel compounds which enhance the entry of L-arginine into cells. These compounds improve endothelial function, and thereby have the potential to retard the progression of vascular disease in conditions such as hypertension, heart failure and diabetes. This new class of drugs may also have other potentially, relevant pharmacological actions, including anti-hypertensive and anti-anginal actions.
[0015] In a first aspect, the invention provides a compound which is able to modulate L-arginine transport into cells, in which the compound is of formula I
where
[0016] A is a methylene group or is absent;
[0017] G is O or is absent;
[0018] R 1 is selected from the group consisting of hydrogen, thio, amino, and optionally substituted lower alkyl, lower alkylamino, arylamino, aralkylamino, heteroarylamino, heteroaralkylamino, lower alkyloxy, aryloxy, heteroaryloxy, cycloalkyloxy, cycloheteroalkyloxy, aralkyloxy, heteroaralkyloxy, (cycloalkyl)alkyloxy, (cycloheteroalkyl)alkyloxy, lower alkylthio, arylthio, heteroarylthio, cycloalkylthio, cycloheteroalkylthio, aralkylthio, heteroaralkylthio, (cycloalkyl)alkylthio, (cycloheteroalkyl)alkylthio, imino lower alkyl, iminocycloalkyl, iminocycloheteroalkyl, iminoaralkyl, iminoheteroaralkyl, (cycloalkyl)iminoalkyl, (cycloheteroalkyl)iminoalkyl, (cycloiminoalkyl)alkyl, (cycloiminoheteroalkyl)alkyl, oximinoloweralkyl, oximinocycloalkyl, oximinocycloheteroalkyl, oximinoaralkyl, oximinoheteroaralkyl, (cycloalkyl)oximinoalkyl, (cyclooximinoalkyl)alkyl, (cyclooximinoheteroalkyl)alkyl, and (cycloheteroalkyl)oximinoalkyl; and
[0019] R 2 , R 3 and R 4 are selected from the group consisting of hydrogen, optionally substituted lower alkyl, aryl, aralkyl, heteroaryl, heteroaralkyl, cycloalkyl, and cycloheteroalkyl.
[0020] Preferably A is absent, R 1 is amino or hydroxyl, and G is O;
[0021] R 2 is alkyl or cycloalkyl when G is O.
[0022] In a preferred embodiment, the compound is of formula II
in which
[0023] R 1 is cycloalkyl of 4-6 carbons;
[0024] R 2 is trihaloalkyl of 1-3 carbon atoms, or is absent;
[0025] R 3 is a halogen or is absent; and
[0026] R 4 is a halogen, or is trihaloalkyl of 1 to 3 carbon atoms.
[0027] Preferably R 1 is cyclobutyl or cyclohexyl;
[0028] R 2 is chlorine or absent; and
[0029] R 4 is chlorine or trifluoromethyl.
[0030] More preferably both R 2 and R 4 are, trifluoromethyl and R 3 is absent, or both R 3 and R 4 are chlorine and R 2 is absent.
[0031] In a particularly preferred embodiment, the compound is one of the following compounds shown in Table 1:
TABLE 1 Structure Structure Name 3-Cyclobutylmethoxy-4-[N′-(3,5- trifluoromethyl-benzyl)-guanidino]- benzamide 3-Cyclobutylmethoxy-4-[N′-(3,4-di- chloro-benzyl)-guanidino]-benzamide 3-Cyclobutylmethoxy-4-[N′-(2-fluoro- benzyl)-guanidino]-benzamide 3-Cyclobutylmethoxy-4-[N′-(4-methyl- benzyl)-guanidino]-benzamide 3-Cyclobutylmethoxy-4-[N′-(2-methoxy- benzyl)-guanidino]-benzamide 3-Cyclobutylmethoxy-4-(N′-cyclohexyl- guanidino)-benzamide 3-Cyclopropylmethoxy-4-[N′-(2-phenyl- propyl)-guanidino]-benzamide 4-[N′-(2-Phenyl-propyl)-guanidino]- 3-(tetrahydro-pyran-2-ylmethoxy)- benzamide 4-(N′-Benzyl-guanidino)-3-(tetrahydro- pyran-2-ylmethoxy)-benzamide 4-(N′-Benzo[1,3]dioxol-5-ylmethyl- guanidino)-3-(tetrahydro-pyran-2- ylmethoxy)-benzamide 4-(N′-Isobutyl-guanidino)-3-(tetrahydro- pyran-2-ylmethoxy)-benzamide 3-Cyclohexylmethoxy-4-[N′-(3,5- trifluoromethyl- benzyl)-guanidino]-benzamide 3-Cyclohexylmethoxy-4-[N′-(3,4-di- chloro-benzyl)-guanidino]-benzamide 3-Cyclohexylmethoxy-4-[N′-(2-methoxy- benzyl)-guanidino]-benzamide 4-(N′-Benzyl-guanidino)-3-cyclohexyl- methoxy-benzamide 3-Cyclohexylmethoxy-4-(N′-cyclohexyl- methyl-guanidino)-benzamide 3-Benzyloxy-4-{N-[(5-nitro-pyridin- 2-ylamino)-methyl]-guanidino}- benzamide 4-(N′-Benzyl-guanidino)-3-benzyloxy- benzamide 3-Benzyloxy-4-(N′-furan-2-ylmethyl- guanidino)-benzamide 4-(N′-Furan-2-ylmethyl-guanidino)-3- (3-methyl-benzyloxy)-benzamide
[0032] In a second aspect, the invention provides a library of compounds of formula I as defined above, or a sub-library thereof.
[0033] It will be clearly understood that the invention encompasses compounds which are able either to up-regulate or to down-regulate transport of L-arginine cross-cell membranes. Preferably the compounds are able to up-regulate such transport. More preferably the compounds of the invention enhance transport of L-arginine into cells, thereby stimulating NO production. Even more preferably the compounds up-regulate the activity of constitutive endothelial NOS (eNOS).
[0034] We have found that some compounds according to the invention, eg plate 1, G10 have a biphasic effect; they enhance L-arginine transport at low concentration, and inhibit such transport at high concentration. Thus a single compound may have both up-regulatory and down-regulatory activity.
[0035] The invention also encompasses methods of synthesis of the compounds.
[0036] According to a third aspect, the invention provides a composition comprising a compound of formula I, together with a pharmaceutically-acceptable carrier.
[0037] According to a fourth aspect, the invention provides a method of treatment of a condition associated with underactivity or hyperactivity of the NO synthetic pathway, comprising the step of administering an effective amount of a compound according to the invention to a subject in need of such treatment.
[0038] It is contemplated that in one preferred embodiment, the NO synthetic pathway is underactive; more preferably the condition is one in which vasodilatation is beneficial, for example, congestive heart failure, coronary artery disease, atherosclerosis, hypertension, diabetes-associated vascular disease, coronary vascular disease, or peripheral vascular disease.
[0039] In an alternative embodiment, the NO synthetic pathway is hyperactive; for example, the condition is sepsis, inflammation, including arthritis, or chronic liver disease. Preferably the condition is one associated with abnormal transport of L-arginine.
[0040] The subject may be a human, or may be a domestic or companion animal. While it is particularly contemplated that the compounds of the invention are suitable for use in medical treatment of humans, they are also applicable to veterinary treatment, including treatment of companion animals such as dogs and cats, and domestic animals such as horses, cattle and sheep, or zoo animals such as primates, felids, canids, bovids, and ungulates.
[0041] Methods and pharmaceutical carriers for preparation of pharmaceutical compositions are well known in the art, as set out in textbooks such as Remington's Pharmaceutical Sciences, 20th Edition, Williams & Wilkins, USA.
[0042] The compounds and compositions of the invention may be administered by any suitable route, and the person skilled in the art will readily be able to determine the most suitable route and dose for the condition to be treated. Dosage will be at the discretion of the attendant physician or veterinarian, and will depend on the nature and state of the condition to be treated, the age and general state of health of the subject to be treated, the route of administration, and any previous treatment which may have been administered.
[0043] The carrier or diluent, and other excipients, will depend on the route of administration, and again the person skilled in the art will readily be able to determine the most suitable formulation for each particular case.
[0044] In addition to treatment of cardiovascular conditions, it is contemplated that the compounds of the invention will be useful for modulation of the thrombin pathway, and consequently for treatment of abnormalities of blood clotting, and for treatment of sepsis.
[0045] While oral treatment is preferred, other routes may also be used, for example intravenous or intra-arterial injection or infusion, buccal, sub-lingual, or intranasal administration.
[0046] It will be clearly understood that the compounds of the invention may also be used in conjunction with one or more other agents which are useful in the treatment of heart failure. Ten agents in this class are in current clinical use; these include acetyl cholinesterase inhibitors such as captopril and enalapril; angiotensin receptor blockers (AT 1 antagonists); atrial natriuretic peptides; vasopeptidase inhibitors (ACE/neutral endopeptidase inhibitors); α- and β-blockers, including selective α- and β-adrenergic receptor antagonists, many of which are available; mineralocorticoid receptor antagonists; endothelin receptor antagonists; and endothelium converting enzyme antagonists. The person skilled in the art will be aware of a wide variety of suitable agents, and the topic has recently been reviewed (Macor & Kowala, 2000).
[0047] Preferably the compound of the invention is used in conjunction with an ACE inhibitor, a neutral endopeptidase inhibitor, or a β-blocker.
BRIEF DESCRIPTION OF THE FIGURES
[0048] FIG. 1 is a schematic representation summarising the role of NO in vascular relaxation.
[0049] FIG. 2 shows the results of experiments on the effect of four different compounds according to the invention on the uptake of radioactive-labelled L-arginine into HeLa cells. C: Control performed in the absence of test compound. The vertical axis shows average disintegrations per minute/mg test compound, and the horizontal axis shows the concentration of test compound, expressed as log 10 (drug concentration). Panel A: Compound A4; Panel B: Compound A7; Panel C: G10; Panel D: Compound H4.
[0050] FIG. 3 shows the results of experiments to test the stimulatory effects of compounds of the invention on arginine uptake by the endothelial cell line EA.hy.926.
[0051] FIG. 4 illustrates the augmentation of vascular relaxation produced by increasing concentrations of acetyl choline in the absence of and presence of test compounds. C indicates control.
DETAILED DESCRIPTION OF THE INVENTION
[0052] The invention will now be described in detail by way of reference only to the following non-limiting examples and drawings.
[0053] Abbreviations used herein are as follows:
[0000] amu atomic mass unit
[0000] CH 2 Cl 2 dichloromethane
[0000] Cs 2 CO 3 caesium carbonate (anhydrous)
[0000] DIC diisopropyl carbodiimide
[0000] DMAP dimethylaminopyridine
[0000] DMF N,N′-dimethylformamide
[0000] DMSO dimethyl sulfoxide
[0000] ESMS electrospray mass spectroscopy
[0000] H 2 O water
[0000] HPLC high performance liquid chromatography
[0000] LC/MS liquid chromatography/mass spectroscopy
[0000] MeCN acetonitrile
[0000] MS mass spectroscopy
[0000] MW molecular weight
[0000] {M+H} + molecular ion
[0000] rt room temperature
[0000] THF tetrahydrofuran
[0000] TFA trifluoroacetic acid
[0000] t R retention time
[0000] Definitions
[0054] Terms used in this specification have the following meanings:
[0000] Combinatorial Library
[0055] A “combinatorial library” or “array” is an intentionally created collection of differing molecules which can be prepared synthetically and screened for biological activity in a variety of different formats, such as libraries of soluble molecules, libraries of molecules bound to a solid support. Typically, combinatorial libraries contain between about 6 and two million compounds. In one embodiment, combinatorial libraries contain between about 48 and 1 million compounds. For example, combinatorial libraries may contain between about 96 and 250,000 compounds. In another embodiment, combinatorial libraries may contain about 40 to 100 compounds.
[0056] Most of the compounds synthesised and described in this application are synthesised using the techniques of combinatorial chemistry to produce combinatorial libraries. In contrast to traditional chemical synthesis, in which a unique compound is synthesised, combinatorial chemistry permits the reaction of a family of reagents A 1 to A n (the building-blocks) with a second family of reagents B 1 to B m , generating nXm possible combinations (the combinatorial library).
[0057] A key feature of combinatorial techniques is that thousands of molecules can be screened in a small number of assays. To detect an active sequence generated via a combinatorial technique, the concentration of the active molecule is selected to be sufficiently great that the molecule can be detected within the sensitivity of the chosen assay. It will be appreciated that the number of unique molecules within a subset produced via a combinatorial technique depends on the number of positions of substitution and the number of different substituents employed.
[0000] Optionally Substituted
[0058] “Optionally substituted” refers to the replacement of hydrogen with a monovalent or divalent radical. Suitable substituent groups include hydroxyl, nitro, amino, imino, cyano, halo, thio, thioamido, amidino, oxo, oxamidino, methoxamidino, imidino, guanidino, sulfonamido, carboxyl, formyl, lower alkyl, halolower alkyl, lower alkoxy, halolower alkoxy, lower alkoxyalkyl, alkylcarbonyl, arylcarbonyl, aralkylcarbonyl, heteroarylcarbonyl, heteroaralkylcarbonyl, alkylthio, aminoalkyl, cyanoalkyl, and the like. The substituent group can itself be substituted.
[0059] The group substituted on to the substituent group can be, for example, carboxyl, halo, nitro, amino, cyano, hydroxyl, lower alkyl, lower alkoxy, aminocarbonyl, —SR, thioamido, —SO 3 H, —SO 2 R or cycloalkyl, where R is typically hydrogen, hydroxyl or lower alkyl. When the substituted substituent includes a straight chain group, the substitution can occur either within the chain (e.g., 2-hydroxypropyl, 2-aminobutyl, and the like) or at the chain terminus (e.g., 2-25 hydroxyethyl, 3-cyanopropyl, and the like). Substituted substituents can be straight chain, branched or cyclic arrangements of covalently bonded carbon or heteroatoms.
[0000] Lower Alkyl and Related Terms
[0060] “Lower alkyl” refers to branched or straight chain alkyl groups comprising 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms which independently are unsubstituted or substituted, e.g., with one or more halogen, hydroxyl or other groups. Examples of lower alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, n-hexyl, neopentyl, trifluoromethyl, pentafluoroethyl, and the like.
[0061] “Alkylenyl” refers to a divalent straight chain or branched chain saturated aliphatic radical having from 1 to 10 carbon atoms. Typical alkylenyl groups employed in compounds of the present invention are lower alkylenyl groups that have from 1 to about 6 carbon atoms in their backbone. “Alkenyl” refers to straight chain, branched, or cyclic radicals having one or more double bonds and from 2 to 20 carbon atoms, preferably 2 to 6 carbon atoms. “Alkynyl” refers to straight chain, branched, or cyclic radicals having one or more triple bonds and from 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms.
[0062] The term “halolower alkyl” refers to a lower alkyl radical substituted with one or more halogen atoms. “Lower alkoxy” as used herein refers to RO—, where R is lower alkyl. Representative examples of lower alkoxy groups include methoxy, ethoxy, t-butoxy, trifluoromethoxy and the like.
[0063] “Lower alkythio” refers to RS—, where R is lower alkyl.
[0064] “Cycloalkyl” refers to a mono- or polycyclic lower alkyl substituent. Typical cycloalkyl substituents have from 3 to 8 backbone (i.e., ring) atoms, in which each backbone atom is optionally substituted carbon. When used in context with cycloalkyl substituents, the term “polycyclic” refers to fused, non-fused cyclic carbon structures and spirocycles. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, bornyl, norbornyl, and the like.
[0065] The term “cycloheteroalkyl” refers to cycloalkyl substituents that have from 1 to 5, and more typically from 1 to 4 heteroatoms (i.e., non-carbon atoms such as nitrogen, sulfur, and oxygen) in the ring structure, with the remaining atoms in the ring being optionally substituted carbon. Representative heterocycloalkyl moieties include morpholino, piperazinyl, piperidinyl, pyrrolidinyl, methylpryolidinyl, pyrrolidinone-yl, and the like.
[0066] The terms “(cycloalkyl)alkyl” and “(cycloheteroalkyl)alkyl” refer to alkyl chains substituted with cycloalkyl and cycloheteroalkyl groups respectively.
[0000] Halo
[0067] “Halo” refers to a halogen radical, such as fluorine, chlorine, bromine, or iodine.
[0000] Aryl and Related Terms
[0068] “Aryl” refers to monocyclic and polycyclic aromatic groups, or fused ring systems having at least one aromatic ring, having from 3 to 14 backbone carbon atoms. Examples of aryl groups include phenyl, naphthyl, dihydronaphthyl, tetrahydronaphthyl, and the like.
[0069] “Aralkyl” refers to an alkyl group substituted with an aryl group. Typically, aralkyl groups employed in compounds of the present invention have from 1 to 6 carbon atoms incorporated within the alkyl portion of the aralkyl group.
[0070] Suitable aralkyl groups employed in compounds of the present invention include benzyl, picolyl, and the like.
[0000] Heteroaryl and Related Terms
[0071] The term “heteroaryl” refers to aryl groups having from one to four heteroatoms as ring atoms in an aromatic ring, with the remainder of the ring atoms being aromatic or non-aromatic carbon atoms. When used in connection with aryl substituents, the term “polycyclic” refers to fused and non-fused cyclic structures in which at least one cyclic structure is aromatic, such as benzodioxozolo, naphthyl, and the like. Exemplary heteroaryl moieties employed as substituents in compounds of the present invention include pyridyl, pyrimidinyl, thiazolyl, indolyl, imidazolyl, oxadiazolyl, tetrazolyl, pyrazinyl, triazolyl, thiophenyl, furanyl, quinolinyl, purinyl, benzothiazolyl, benzopyridyl, and benzimidazolyl, and the like.
[0000] Amino and Related Terms
[0072] “Amino” refers to the group —NH 2 . The term “lower alkylamino” refers to the group —NRR′, where R and R′ are each independently selected from hydrogen or loweralkyl. The term “arylamino” refers to the group —NRR′ where R is aryl and R′ is hydrogen, lower alkyl, aryl, or aralkyl. The term “aralkylamino” refers to the group —NRR′ where R is aralkyl and R′ is hydrogen, loweralkyl, aryl, or aralkyl. The terms “heteroarylamino” and heteroaralkylamino” are defined by analogy to arylamino and aralkylamino.
[0000] Thio and Related Terms
[0073] The term “thio” refers to —SH. The terms “lower alkylthio”, “arylthio”, “heteroarylthio”, “cycloalkylthio”, “cycloheteroalkylthio”, “aralkylthio”, “heteroaralkylthio”, “(cycloalkyl)alkylthio”, and “(cycloheteroalkyl)alkylthio” refer to —SR, where R is optionally substituted lower alkyl, aryl, heteroaryl; cycloalkyl, cycloheteroalkyl, aralkyl, heteroaralkyl, (cycloalkyl)alkyl, and (cycloheteroalkyl)alkyl respectively.
[0074] “Carboxyl” refers to —C(O)OH.
[0000] Imino and Oximino
[0075] The term “imino” refers to the group —C(═NR)—, where R can be hydrogen or optionally substituted lower alkyl, aryl, heteroaryl, or heteroaralkyl respectively. The terms “iminoloweralkyl”, “iminocycloalkyl”, “ininocycloheteroalkyl”, “iminoaralkyl”, “iminoheteroaralkyl”, “(cycloalkyl)iminoalkyl”, “(cycloiminoalkyl)alkyl”, “(cycloiminoheteroalkyl)alkyl”, and “(cycloheteroalkyl)iminoalkyl” refer to optionally substituted lower alkyl, cycloalkyl, cycloheteroalkyl, aralkyl, heteroaralkyl, (cycloalkyl)alkyl, and (cycloheteroalkyl)alkyl groups that include an imino group, respectively.
[0076] The term “oximino” refers to the group —C(═NOR)—, where R can be hydrogen (“hydroximino”) or optionally substituted lower alkyl, aryl, heteroaryl, or heteroaralkyl respectively. The terms “oximinoloweralkyl”, “oximinocycloalkyl”, “oximinocycloheteroalkyl”, “oximinoaralkyl”, “oximinoheteroaralkyl”, “(cycloalkyl)oximinoalkyl”, “(cyclooximinoalkyl)alkyl”, “(cyclooximinoheteroalkyl)alkyl”, and (cycloheteroalkyl)oximinoalkyl” refer to optionally substituted lower alkyl, cycloalkyl, cycloheteroalkyl, aralkyl, heteroaralkyl, (cycloalkyl)alkyl, and (cycloheteroalkyl)alkyl groups that include an oximino group, respectively.
[0000] Methylene and Methine
[0077] The term “methylene” refers to an unsubstituted, monosubstituted, or disubstituted carbon atom having a formal SP 3 hybridization (i.e., —CRR′—, where R and R′ are hydrogen or independent substituents).
[0078] The term “methine” as used herein refers to an unsubstituted or carbon atom having a formal sp 2 hybridization (i.e., 10 —CR═ or ═CR—, where R is hydrogen a substituent).
[0079] It will be appreciated by those skilled in the art that the compounds of formula (I) may be modified to provide pharmaceutically acceptable derivatives thereof at any of the functional groups in the compounds of formula (I). Of particular interest as such derivatives are compounds modified at the carboxyl function, hydroxyl functions or at the guanidino or amino groups. Thus compounds of interest include C 1-6 alkyl esters, such as methyl, ethyl, propyl or isopropyl esters, aryl esters, such as phenyl, benzoyl esters, and C 1-6 acetyl esters of the compounds of formula (I).
[0080] The term “pharmaceutically acceptable derivative” means any pharmaceutically acceptable salt, ester or salt of such ester of a compound of formula (I) or any other compound which, upon administration to the recipient, is capable of providing a compound of formula (I) or a biologically active metabolite or residue thereof.
[0081] Pharmaceutically acceptable salts of the compounds of formula (I) include those derived from pharmaceutically acceptable inorganic and organic acids and bases. Examples of suitable acids include hydrochloric, hydrobromic, sulphuric, nitric, perchloric, fumaric, maleic, phosphoric, glycolic, lactic, salicylic, succinic, toluene-p-sulphonic, tartaric, acetic, citric, methanesulphonic, formic, benzoic, malonic, naphthalene-2-sulphbnic and benzenesulphonic acids. Other acids such as oxalic acid, while not in themselves pharmaceutically acceptable, may be useful in the preparation of salts useful as intermediates in obtaining compounds of the invention and their pharmaceutically acceptable acid addition salts.
[0082] Salts derived from appropriate bases include alkali metal (eg. sodium), alkaline earth metal (eg. magnesium), ammonium, and NR 4 + (where R is C 1-4 alkyl) salts.
[0083] For the purposes of this specification it will be clearly understood that the word “comprising” means “including but not limited to”, and that the word “comprises” has a corresponding meaning.
[0084] As used herein, the singular forms “a”, “an”, and “the” include the corresponding plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “an enzyme” includes a plurality of such enzymes, and a reference to “an amino acid” is a reference to one or more amino acids. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any materials and methods similar or equivalent to those described herein can be used to practice or test the present invention, the preferred materials and methods are now described.
[0085] Generally, the terms “treating”, “treatment” and the like are used herein to mean affecting a subject, tissue or cell to obtain a desired pharmacological and/or physiological effect. The effect may be prophylactic in terms of completely or partially preventing a disease or sign or symptom thereof, and/or may be therapeutic in terms of a partial or complete cure of a disease. “Treating” as used herein covers any treatment of, or prevention of disease in a vertebrate, a mammal, particularly a human, and includes preventing the disease from occurring in a subject who may be predisposed to the disease, but has not yet been diagnosed as having it; inhibiting the disease, ie., arresting its development; or relieving or ameliorating the effects of the disease, ie., cause regression of the effects of the disease.
[0086] The invention includes various pharmaceutical compositions useful for ameliorating disease. The pharmaceutical compositions according to one embodiment of the invention are prepared by bringing a compound of formula I, or an analogue, derivative or salt thereof, and one or more pharmaceutically-active agents or combinations of a compound of formula I and one or more other pharmaceutically-active agents, into a form suitable for administration to a subject, using carriers, excipients and additives or auxiliaries.
[0087] Frequently used carriers or auxiliaries include magnesium carbonate, titanium dioxide, lactose, mannitol and other sugars, talc, milk protein, gelatin, starch, vitamins, cellulose and its derivatives, animal and vegetable oils, polyethylene glycols and solvents, such as sterile water, alcohols, glycerol and polyhydric alcohols. Intravenous vehicles include fluid and nutrient replenishers. Preservatives include antimicrobials, anti-oxidants, chelating agents and inert gases. Other pharmaceutically acceptable carriers include aqueous solutions, non-toxic excipients, including salts, preservatives, buffers and the like, as described, for instance, in Remington's Pharmaceutical Sciences, 20th ed. Williams & Wilkins (2000) and The British National Formulary 43rd ed. (British Medical Association and Royal Pharmaceutical Society of Great Britain, 2002; http://bnf.rhn.net), the contents of which are hereby incorporated by reference. The pH and exact concentration of the various components of the pharmaceutical composition are adjusted according to routine skills in the art. See Goodman and Gilman's The Pharmacological Basis for Therapeutics (7th ed., 1985).
[0088] The pharmaceutical compositions are preferably prepared and administered in dosage units. Solid dosage units include tablets, capsules and suppositories. For treatment of a subject, depending on activity of the compound, manner of administration, nature and severity of the disorder, age and body weight of the subject, different daily doses can be used. Under certain circumstances, however, higher or lower daily doses may be appropriate. The administration of the daily dose can be carried out both by single administration in the form of an individual dose unit or else several smaller dose units and also by multiple administration of subdivided doses at specific intervals.
[0089] The pharmaceutical compositions according to the invention may be administered locally or systemically in a therapeutically effective dose. Amounts effective for this use will, of course, depend on the severity of the disease and the weight and general state of the subject. Typically, dosages used in vitro may provide useful guidance in the amounts useful for in situ administration of the pharmaceutical composition, and animal models may be used to determine effective dosages for treatment of the cytotoxic side effects. Various considerations are described, eg., in Langer, Science, 249: 1527, (1990). Formulations for oral use may be in the form of hard gelatin capsules, in which the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin. They may also be in the form of soft gelatin capsules, in which the active ingredient is mixed with water or an oil medium, such as peanut oil, liquid paraffin or olive oil.
[0090] Aqueous suspensions normally contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients may be suspending agents such as sodium carboxymethyl cellulose, methyl cellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents, which may be (a) a naturally occurring phosphatide such as lecithin; (b) a condensation product of an alkylene oxide with a fatty acid, for example, polyoxyethylene stearate; (c) a condensation product of ethylene oxide with a long chain aliphatic alcohol, for example, heptadecaethylenoxycetanol; (d) a condensation product of ethylene oxide with a partial ester derived from a fatty acid and hexitol such as polyoxyethylene sorbitol monooleate, or (e) a condensation product of ethylene oxide with a partial ester derived from fatty acids and hexitol anhydrides, for example polyoxyethylene sorbitan monooleate.
[0091] The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to known methods using suitable dispersing or wetting agents and suspending agents such as those mentioned above. The sterile injectable preparation may also a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents which may be employed are water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed, including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid may be used in the preparation of injectables.
[0092] Compounds of formula I may 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.
[0093] Dosage levels of the compound of formula I of the present invention will usually be of the order of about 0.5 mg to about 20 mg per kilogram body weight, with a preferred dosage range between about 0.5 mg to about 10 mg per kilogram body weight per day (from about 0.5 g to about 3 g per patient per day). The amount of active ingredient which may be combined with the carrier materials to produce a single dosage will vary, depending upon the host to be treated and the particular mode of administration. For example, a formulation intended for oral administration to humans may contain about 5 mg to 1 g of an active compound with an appropriate and convenient amount of carrier material, which may vary from about 5 to 95 percent of the total composition. Dosage unit forms will generally contain between from about 5 mg to 500 mg of active ingredient.
[0094] It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination and the severity of the particular disease undergoing therapy.
[0095] In addition, some of the compounds of the invention may form solvates with water or common organic solvents. Such solvates are encompassed within the scope of the invention.
[0096] The compounds of the invention may additionally be combined with other compounds to provide an operative combination. It is intended to include any chemically compatible combination of pharmaceutically-active agents, as long as the combination does not eliminate the activity of the compound of formula I of this invention.
[0000] Synthesis of the Compounds of the Invention
[0097] The compounds of the present invention can be synthesized using techniques and materials known to those of skill in the art (Carey and Sundberg 1983; Carey and Sundberg 1983; Greene and Wuts 1991; March 1992). Starting materials for the compounds of the invention may be obtained using standard techniques and commercially available precursor materials, such as those available from Aldrich Chemical Co. (Milwaukee, Wis.), Sigma
[0098] Chemical Co. (St. Louis, Mo.), Lancaster Synthesis (Windham, N.H.), Apin Chemicals, Ltd. (New Brunswick, N.J.), Ryan Scientific (Columbia, S.C.), Maybridge (Cornwall, England), Arcos (Pittsburgh, Pa.), and Trans World Chemicals (Rockville, Md.). The procedures described herein for synthesizing the compounds of the invention may include one or more steps of protection and deprotection, e.g., the formation and removal of acetal groups (Greene and Wuts 1991). In addition, the synthetic procedures disclosed below can include various purifications, such as column chromatography, flash chromatography, thin-layer chromatography (“TLC”), recrystallization, distillation, high-pressure liquid chromatography (“HPLC”) and the like. Various techniques well known in the chemical arts for the identification and quantification of chemical reaction products, such as proton and carbon-13 nuclear magnetic resonance ( 1 H and 13 C NMR), infrared and ultraviolet spectroscopy (“IR” and “UV”), X-ray crystallography, elemental analysis (“EA”).
[0099] HPLC and mass spectroscopy (“MS”) can be used for identification, quantitation and purification as well.
[0100] Most of the compounds were synthesised using the technique of Solid Phase Chemistry (Ellman 1996). For many years we have used a multipin array system for solid-phase combinatorial peptide synthesis. This system is marketed by Mimotopes Pty Ltd, Clayton, Australia, and is used for synthesising libraries of organic compounds such as amino acid analogues, and for synthesising peptides and peptide libraries. The proprietary pin, Crown™ and SynPhase™ Lantern support systems utilise polyethylene or polypropylene copolymers grafted with 2-hydroxyethyl methacrylate polymer(HEMA), methacrylic acid/dimethylacrylamide polymer(MA/DMA) or polystyrene (PS) (Maeji et al. 1994).
[0101] In particular, suitable solid supports include resins, graft polymers such as Crown™ and SynPhase™ Lantern supports, and other derivatised surfaces suitable for solid phase synthesis. The solid support may be a resin of the type used for example in solid-phase peptide synthesis. Many suitable resins are known in the art, for example methylbenzhydrylamine (MBHA) resin, amino or carboxy tentagel resins, or 4-sulphamylbenzyl AM resin. One particularly preferred class of supports is aminomethylated polystyrene-grafted polyethylene or polypropylene, such as the Rink linker-derivatised aminomethylated polystyrene-grafted SynPhase™ lantern manufactured by Mimotopes Pty Ltd. (product code SPPSDRAM). Typical loadings are in the range of 34-36 micromole per unit. Another preferred support is the grafted resin described in our International patent application No. PCT/AU01/00850.
[0102] Most of the compounds synthesised and described in the application are synthesised using the techniques of combinatorial chemistry to produce combinatorial libraries. As opposed to traditional chemical synthesis where a unique compound is synthesised, combinatorial chemistry permits the reaction of a family of reagents A 1 to A n (the building-blocks) with a second family of reagents B 1 to B m generating nXm possible combinations (the combinatorial library).
EXAMPLE 1
Synthesis of a Library of 180 Aryl Ether Guanidine Compounds (Library 0006)
[0103] Library M0006 is a single compound library of 180 aryl ether guanidines in which there are two points of diversity. The scaffold for this library is a compound of formula II, in which R 2 is derived from an alkyl halide and R 4 is derived from a primary amine.
[0104] Thus the compounds present a subset of formula I in which A is absent, R 1 is amino, R 2 is derived from an alkyl halide, G is O, R 3 is H and R 4 is derived from a primary amine.
[0105] The library was synthesised using 9 alkyl-halides for the R 2 substituents and 20 different amines for the R 4 substituents. This combination results in the generation of 180 compounds. The purity, as estimated by RP-HPLC at 214 nm, of compounds from Library M0006 averages 73.6%, and ranges from 56% to 88% (s.d.=7%) determined from an analytical set of 41 compounds (23% of the total number of compounds synthesised).
[0000] Synthesis
[0106] 3-hydroxy-4-nitrobenzoic acid was coupled on to PS Rink Lanterns (Mimotopes Pty Ltd, Clayton, Victoria, Australia) loading capacity 35 μmol) using DIC/DMAP. The Lanterns were then treated with a solution of 10% ethanolamine in DMF to remove any concomitantly-formed esters. Deprotonation of the phenol with a potassium hydride/DMF solution followed by reaction with 9 alkyl halides generated 9 different aryl ethers. Using a solution of tin(II) chloride dihydrate in DMF, the nitro group in a 4-position was reduced to the corresponding aniline. The 180 Lanterns, derivatised with 9 different anilines were then treated with Fmoc-NCS. The in situ thioureas formed were then S-methylated with iodomethane. Subsequent reaction with 20 different amines resulted in the formation of the 20 different guanidines in the 4-position. Cleavage with 20% TFA/DCM afforded 180 aryl ether guanidines, which constitute Library M0006. This is summarised in Reaction Scheme 1.
(i) Coupling of 3-Hydroxy-4-nitrobenzoic Acid
[0107] Nine sets of 20 PS-D-RAM Lanterns (batch 1517, loading capacity 35 μmol) were reacted with a solution of 3-hydroxy-4-nitrobenzoic acid (0.2M), DIC (0.1M) and DMAP (0.05M) in DCM overnight at room temperature. The reaction solution was then drained and the Lanterns washed with DCM (4×20 min) and DMF (8×20 min). Concomitantly-formed esters were then cleaved using a solution of 10% ethanolamine/DMF: Lanterns were treated with 10% ethanolamine/DMF (1×15 min) followed by DMF (1 or 2×15 min); the Lanterns were given a sufficient number of treatments as to afford an entirely colourless eluent. When no further colour was observed, the Lanterns were washed with a solution of 50% AcOH (AR grade)/DCM (2×20 min) followed by DCM (4×15 min). A stain test of 0.2% bromophenol blue/DMF performed on a portion of one Lantern gave a negative result. The Lanterns were air-dried.
[0000] (ii) Alkylation
[0108] The Lanterns from step (i) were treated with a slurry of excess potassium hydride freshly extracted from mineral oil in anhydrous DMF for 30 min; then the Lanterns were rinsed twice with anhydrous DMF (1st cycle for 5 min; second cycle for about 30 min, or until the R1-X/Cs 2 CO 3 solutions were prepared). Nine solutions containing the appropriate alkylating reagent and Cs 2 CO 3 in distilled DMF were prepared. The order of addition was cesium carbonate, then DMF, then alkylating reagent. The different substituents used for R 2 and R 4 , and the alkylating conditions used to generate R 2 , are summarised in Tables 2 to 4 respectively.
TABLE 2 Summary of R 2 -group structures and details for library M0006 Frag- ment Reagent Tag R 2 -Group Structure Reagent Name Tag R1m1 (bromomethyl)cyclobutane CCA004 R1m2 (bromomethyl)cyclopropane CCA001 R1m3 2-(bromomethyl)tetrahydro- 2H-pyran CCB001 R1m4 (bromomethyl)cyclohexane CCA002 R1m8 2-phenoxyethyl bromide CCB004 R1m9 benzyl bromide CCC001 R1m10 3-(trifluoromethyl)benzyl bromide a-bromo-a,a,a-m- trifluoroxylene CCD018 R1m11 3-bromobenzyl bromide CCD019 R1m12 4-fluorobenzyl bromide CCD020
[0109]
TABLE 3
Summary of R 4 -group structures and details for library M0006
Fragment
Reagent
Tag
R 4 -Group Structure
Reagent Name
Tag
r2m4
3,5-bis(trifluoromethyl)benzylamine
DAD005
r2m5
2-(2-aminoethylamino)-5-nitropyridine
DAG001
r2m7
4-fluorophenethylamine
DAD023
r2m8
3,4-dichlorobenzylamine
DAD024
r2m9
2-methylbenzylamine
DAC009
r2m12
4-(triftuoromethyl)benzylamine
DAD006
r2m13
1-amino-2-phenylpropane β-phenethylamine
DAC008
r2m16
2-fluorobenzylamine
DAD004
r2m17
4-methylbenzylamine
DAC007
r2m18
2-methoxybenzylamine
DAD009
r2m20
benzylamine
DAC003
r2m22
piperonylamine
DAD002
r2m24
hexylamine
DAA002
r2m25
isobutylamine
DAA010
r2m40
2-(4-chlorophenyl)ethylamine
DAD008
r2m46
2-(trifluoromethyl)benzylamine
DAD029
r2m53
4-chlorobenzylamine
DAD034
r2m58
cyclohexylamine
DAA001
r2m60
cyclohexanemethylamine
DAA003
r2m62
furfurylamine
DAG005
[0110]
TABLE 4
Conditions Employed for Alkylating Reagents
Alkyl Halide
Cesium(I)
Reaction
Reaction
Alkylating Reagent
Concentration
Concentration
Time
Temperature
(Bromomethyl)cyclobutane
1.0 M
0.3 M
24 h
100° C.
(Bromomethyl)cyclopropane
1.0 M
0.3 M
24 h
100° C.
2-(Bromomethyl)-
1.0 M
0.3 M
24 h
100° C.
tetrahydro-2H-pyran
(Bromomethyl)cyclohexane
1.0 M
0.3 M
24 h
100° C.
2-Phenoxyethyl bromide
1.0 M
0.06 M
24 h
100° C.
Benzyl bromide
1.0 M
0.06 M
24 h
40° C.
3-(Trifluoromethyl)
1.0 M
0.6 M
48 h
100° C.
benzyl bromide
3-Bromobenzyl bromide
1.0 M
0.06 M
24 h
40° C.
4-Fluorobenzyl bromide
1.0 M
0.06 M
24 h
40° C.
[0111] The reaction solution from each flask was then drained, and the Lantern sets transferred to clean 100 mL vessels to facilitate Cs 2 CO 3 removal. The Lanterns were then washed with DMF (distilled) (3×10 min), 50% DMF (distilled)/H 2 O (1×30 min, 1×10 min), DMF (distilled) (2×10 min) and DCM (1×30 min, 2×10 min, 1×2 min). The Lantern sets were then vacuum dried at 40° C.
[0112] The analysis by RP-HPLC of these 9 intermediates showed that full alkylation was not achieved in all cases. Only 3 of the ethers returned raw HPLC purities of >80%. These were (bromomethyl)cyclobutane (r1m1); 2-(bromomethyl)tetrahydro-2H-pyran (r1m3) and (bromomethyl)cyclohexane (r1m4). The remaining sets of Lanterns were therefore re-treated with KH/DMF followed by alkylating reagent at reduced concentration (0.5M). Cs 2 CO 3 was omitted from all second pass reaction solutions. The sets of Lanterns derivatised with benzyl bromide, 3-bromobenzyl bromide and 4-fluorobenzyl bromide were heated to 40° C. for 44 h. Lanterns derivatised with 2-phenoxyethyl bromide and (bromomethyl)cyclopropane were heated to 80° C. for 44 h. The Lantern set derivatised with 3-(trifluoromethyl)benzyl bromide was heated initially to 80° C. for 1 h, then at 40° C. for the remaining 43 h. For reactions involving (bromomethyl)cyclopropane and 2-phenoxyethyl bromide, 2 different solutions of the alkylating reagent were used. After 18.5 h, the first alkyl halide solution was removed, the Lanterns were washed briefly with anhydrous DMF then re-treated with a second solution of the alkylating reagent (0.5M) for the remaining 25.5 h. The Lanterns were then washed with DMF (3×10 min) and DCM (2×10 min) and then vacuum dried at 40° C. overnight.
[0000] (iii) Aniline Formation Using Tin(II) Chloride
[0113] Nine solutions of tin(II) chloride dihydrate (1.0M) in distilled DMF were prepared. These were then added to the nine sets of Lanterns derivatised with the 9 different aryl ethers and allowed to stand overnight at 40° C. The reaction solutions were then drained and the Lanterns washed with DMF (2×30 min), 50% DMF/H 2 O (1×30 min), DMF (1×20 min), DCM (3×10 min). The Lanterns were then vacuum dried for 3 h.
[0000] (iv) Guanidine Formation
[0114] Transponders were inserted into the Lanterns and a TranSort program was created for the directed sort for the R2 group. The Lanterns were treated with Fmoc-NCS (0.2M) in DCM at room temperature for 14 h then at 40° C. for 1 h. The reaction solution was drained and the Lanterns washed with DCM (3×10 min), DMF (3×10 min) and DCM (3×10 min). The Lanterns were then vacuum dried at 40° C. for 1 h.
[0115] The Lanterns were Fmoc-deprotected with 20% piperidine/DMF for 1 h. The piperidine solution was drained and the Lanterns subjected to a second treatment with fresh 20% piperidine/DMF for 45 minutes. The Lanterns were drained and washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0116] A solution of iodomethane (0.2M) in DMF (distilled) was prepared. To this solution was added the Fmoc-deprotected Lanterns. The Lanterns were then stood at room temperature for 1 h. The iodomethane solution was removed and the Lanterns re-treated with a second solution of iodomethane (0.2M) in DMF for 45 min. The Lanterns were drained then washed with DMF (3×10 min) and DCM (3×10 min) and vacuum dried overnight at 40° C.
[0117] Twenty solutions of the corresponding amine (2M) [refer Table 3] in DMSO (AR grade) were prepared. The sets of Lanterns, as sorted using TranSort, were then added to these amine solutions and allowed to stand at 85° C. for 6 h. At the completion of the reaction, the amine solutions were drained and the Lanterns washed with warm DMSO (2×10 min), DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min). The Lanterns were then vacuum dried overnight at 40° C.
[0000] (v) Cleavage from the Solid Phase
[0118] The Lanterns were prepared for cleavage using TranSort. The Lanterns were then cleaved using 1 mL per Lantern of 20% TFA (distilled)/DCM for 1 h using the 2 mL square deep-well format. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator (GeneVac). The resulting material was reconstituted in neat acetonitrile (0.9 mL) and re-evaporated. The samples were dissolved in 90% MeCN/H 2 O for plating purposes and re-evaporated to dryness.
[0000] Analysis
[0119] A selection of 43 compounds was analyzed by reverse phase HPLC and electrospray mass spectrometry, under the following conditions:
[0120] Reverse phase HPLC analysis was carried out using a Rainin Microsorb-MV C18 column, (5 μm 100 Å; 50×4.6 mm), under the following conditions: Eluent A: 0.1% H 3 PO 4 (aq); Eluent B: 0.1% H 3 PO 4 in 90% MeCN (aq); Gradient: 0-100% Buffer B over llmin; Flow rate: 1.5 mL/min; Wavelength detection: 214 nm.
[0121] ESMS was performed on an API III LC/MS/MS instrument (Perkin Elmer/Sciex) using an electrospray inlet, and the following conditions: Solvent: 0.1% ACOH in 60% MeCN (aq); Flow rate: 25 μL/min; Ionspray: 5000V; Orifice plate: 55V; Acquisition time: 2.30 min; Scan range: 100-1000 amu/z; Scan step size: 0.2 amu/z.
[0122] The results are summarised in Table 5. All compounds sampled displayed the target molecular weight. The LC/MS results indicate that at least two ions are detected under each major peak. These are MH + and (MH+122) + . Additionally, there are ions corresponding to (MH+(n×122)) + where n is an integer. An ion of m/z 222 was also detected in the buffer solution of the instrument.
TABLE 5 Summary of Analytical Results Compound Identification HPLC and LC-MS data (214 nm) Compound Monoisotopic Retention Peak Area Target (MH) + ID R Groups FW Time (min) (%) Found Observed M000601A04 r1m1-r2m4 488 8.33 67.7 ✓ 489.1 M000601A05 r1m1-r2m5 427 6.13 70.8 ✓ 428.3 M12812044BP R1m1-r2m8 420 7.41 95.6 ✓ 421.1 M000601B04 r1m1-r2m18 382 6.82 72.4 ✓ 383.3 M000601B05 r1m1-r2m20 352 6.42 75.6 ✓ 353.5 M000601C04 r1m1-r2m60 358 7.46 70.8 ✓ 359.3 M000601C05 r1m1-r2m62 342 5.78 62.2 ✓ 343.3 M000601D04 r1m2-r2m16 356 5.80 76.3 ✓ 357.0 M000601D05 r1m2-r2m17 352 6.34 76.7 ✓ 353.2 M000601E04 r1m2-r2m53 407 6.49 74.3 ✓ 372.9 M000601E05 r1m2-r2m58 330 6.15 60.1 ✓ 331.3 M000601F04 r1m3-r2m12 450 7.00 79.4 ✓ 451.1 M000601F05 r1m3-r2m13 410 6.68 80.1 ✓ 411.4 M000601G04 r1m3-r2m40 430 7.02 78.2 ✓ 431.4 M000601G05 r1m3-r2m46 450 6.75 72.6 ✓ 451.1 M12812044CP R1m4-r2m4 516 8.71 99.3 ✓ 517.1 M000601H04 r1m4-r2m8 448 8.47 73.7 ✓ 449.0 M000601H05 r1m4-r2m9 394 7.86 77.3 ✓ 395.1 M000602A04 r1m4-r2m24 374 8.52 69.9 ✓ 375.3 M000602A05 r1m4-r2m25 346 7.22 69.6 ✓ 347.2 M000602D05 r1m8-r2m4 540 8.51 73.2 ✓ 541.1 M000602E04 r1m8-r2m17 418 7.29 78.0 ✓ 419.1 M000602E05 r1m8-r2m18 434 7.10 79.6 ✓ 435.1 M000602F04 r1m8-r2m58 396 7.14 56.2 ✓ 397.1 M000602F05 r1m8-r2m60 410 7.71 74.3 ✓ 411.4 M000602G04 r1m9-r2m13 402 7.17 76.2 ✓ 403.2 M000602G05 r1m9-r2m16 392 6.48 73.8 ✓ 392.9 M000602H04 r1m9-r2m46 442 7.26 68.8 ✓ 443.0 M000602H05 r1m9-r2m53 408 7.15 77.1 ✓ 409.1 M000603A04 r1m10-r2m9 456 7.84 88.1 ✓ 457.1 M000603A05 r1m10-r2m12 510 8.25 85.8 ✓ 511.2 M000603B04 r1m10-r2m25 408 7.29 78.3 ✓ 409.3 M000603B05 r1m10-r2m40 490 8.33 86.2 ✓ 491.0 M000603C04 r1m11-r2m7 484 7.70 75.5 ✓ 485.3 M000603C05 r1m11-r2m8 520 8.17 77.0 ✓ 523.1 M000603D04 r1m11-r2m22 496 7.09 76.2 ✓ 497.1 M000603D05 r1m11-r2m24 446 8.32 69.3 ✓ 447.0 M000603E04 r1m12-r2m4 528 8.43 62.7 ✓ 529.1 M000603E05 r1m12-r2m5 467 6.32 70.1 ✓ 468.0 M000603F04 r1m12-r2m18 422 6.99 75.1 ✓ 423.3 M000603F05 r1m12-r2m20 392 6.64 76.6 ✓ 392.8 M000603G04 r1m12-r2m60 398 7.56 74.3 ✓ 399.3 M000603G05 r1m12-r2m62 382 6.10 58.3 ✓ 383.2
EXAMPLE 2
Detailed Synthesis of Lead Compound A4
[0123] This compound was also designated M12836152 (compound 7). The synthesis is summarised in Reaction Scheme 2.
[0124] In Reaction Scheme 2: (i) DIC, DMAP, CH 2 Cl 2 , rt, 16 h; (ii) KHt DMF, 100° C., 24 h; (iii) SnCl 2 .2H 2 O, DMF, rt, 24 h; (iv) FmocNCS, CH 2 Cl 2 , rt, 7 h; (v) 20% piperidine/DMF, rt, 40 min, 1 h 20 min, then CH 3 I, DMF, 40 min x2; (vi) DMSO, 75-85° C., 9 h; (vii) 20% TFA/CH 2 Cl 2 , rt, 1 h.
[0000] Synthesis of (1)
[0125] 100 PS-D-RAM SynPhase™ Lanterns (batch 1703-13A, loading capacity 35 μmol) with Rink amide linker attached were Fmoc-deprotected using a solution of premixed 20% piperidine/DMF (v/v) (2×40 min). The piperidine solution was filtered off and the Lanterns washed with DMF (5×20 min) and CH 2 Cl 2 (2×10 min).
[0126] 80 mL of a solution of 3-hydroxy-4-nitrobenzoic acid (0.2M), DIC (0.1M) and DMAP (0.05M) in CH 2 Cl 2 was prepared. The solution was allowed to stand at rt for 3 min then was added to the Fmoc-deprotected Lanterns. The Lanterns were stood at rt for 16 h. The reaction solution was then drained and the Lanterns washed with CH 2 Cl 2 (4×20 min), DMF (8×20 min). Concomitantly-formed ester were then cleaved using alternate solutions of 10% ethanolamine/DMF (v/v) (15 min) and DMF (10 min) until clear spent washing solutions were obtained—approximately 6 cycles. The Lanterns were then washed with 50% CH 3 COOH/CH 2 Cl 2 (v/v) (2×10 min) then CH 2 Cl 2 (3×10 min) and vacuum dried at 40° C. for 1 hour.
[0000] Synthesis of (2)
[0127] The Lanterns from step (i) were subjected to treatments with a slurry of excess potassium hydride (freshly extracted with petroleum ether from mineral oil) in anhydrous DMF for 30 min and 5 min respectively.
[0128] 40 mL of a solution of (bromomethyl)cyclobutane (1.0M) and Cs 2 CO 3 (0.3M) in anhydrous DMF was prepared. The KH-treated Lanterns were then added to this reaction solution and left to stand at 100° C. for 24 h. The reaction solution was drained and the Lanterns transferred to a clean vessel. The Lanterns were washed with DMF (3×10 min), 50% DMF/H 2 O (v/v) (2×30 min), DMF (2×10 min) and CH 2 Cl 2 (4×10 min) then vacuum dried at 40° C. for 1 hour.
[0000] Synthesis of (3)
[0129] 40 mL of a solution of tin(II)chloride dihydrate (1M) in DMF (distilled grade) was prepared. This solution was then added to the Lanterns from step (ii) and stood at rt for 24 h. The reaction solution was drained and the Lanterns washed with DMF (2×5 min), 20% H 2 O/THF (2×30 min, 1×15 min), THF (1×15 min) and CH 2 Cl 2 (4×15 min) then air dried overnight. HPLC (214 nm) t R 4.86 (89.9%) min; LC/MS t R 4.92 (220.9, [M+H] + ; 441.3, [2M+H] + ).
[0000] Synthesis of (4)
[0130] 30 mL of a solution of FmocNCS (0.2M) in CH 2 Cl 2 was prepared. The reaction solution was added to 50 Lanterns from step (iii) and the Lanterns stood at rt for 6.5 h, then heated to 40° C. for the final 0.5 h (total of 7 h reaction time). At the conclusion of the reaction, the FmocNCS solution was drained and the Lanterns washed with CH 2 Cl 2 ; (4×10 min), DMF (2×10 min). These Lanterns were taken immediately to step (v).
[0000] Synthesis of (5)
[0131] The Lanterns were firstly treated with 20% piperidine/DMF (v/v) at rt (2 treatments of 40 min and 1 h 20 min respectively—there were no washes in between treatments). The second piperidine solution was drained and the Lanterns washed with DMF (4×10 min). The lanterns were further reacted immediately.
[0132] A solution of iodomethane (0.2M) in DMF was prepared and added to the Fmoc-deprotected Lanterns. The Lanterns were allowed to stand at rt for 40 min. The iodomethane solution was then removed and the Lanterns subjected to a second solution of iodomethane (0.2M) in DMF for 40 min˜there were no washes in between treatments. After the 40 min was complete, the reaction solution was drained and the Lanterns washed with DMF (5×10 min) and DMSO (1×10 min). The Lanterns were taken immediately to step (vi).
[0000] Synthesis of (6)
[0133] The Lanterns from step (v) were added to a solution of 3,5-bis(trifluoromethyl) benzylamine (2.0M) in DMSO then placed in an oven set to 75° C. for 8.5 h. The temperature of the oven was then increased to 85° C. and the Lanterns reacted for a further 0.5 h. At the completion of the reaction, the amine solution was drained and the Lanterns washed with hot (85° C.) DMSO (2×10 min, 2×30 min), DMF (3×10 min) and CH 2 Cl 2 (3×20 min). The Lanterns were then vacuum dried overnight.
[0000] Synthesis of (7)
[0134] The Lanterns were cleaved using a solution of 20% TFA/CH 2 Cl 2 (v/v). The Lanterns were stood at rt for 1 h, then the cleavage solution was transferred to a 250 mL round bottom flask. The solution was evaporated under reduced pressure to give an orange oil. The oil was dissolved in 90% MeCN/H 2 O and evaporated a second time under reduced pressure, then dissolved again in neat acetonitrile and evaporated under reduced pressure to give an orange oil. The orange oil was then dissolved in neat acetonitrile and purified using preparative LC/MS techniques.
[0135] Reverse phase HPLC analysis was carried out using a Rainin Microsorb-MV C18 column (5 μm 100 Ø; 50×4.6 mm), under the following conditions: Buffer A: 0.1% TFA in H 2 O; Buffer B: 0.1% TFA in 90% MeCN/H 2 O; Gradient: 0-100% Buffer B over 11 min; Flow rate: 1.5 mL/min; Wavelength detection: 214 and 254 nm. The target compound and potential by-products may have varying chromophores, so the HPLC results should not be taken as absolute, but they still give an indication of purity. Sample A4 was analyzed by HPLC using the manual integration method. The results are summarized in Table 6.
TABLE 6 Summary of HPLC results for compound A4 Internal Major peaks; t R Mass ID#: Structure MW* at 214 nm (%) (mg) A4 488.4 7.69, 96.6% 10 MG
[0136] *Molecular weight based on relative atomic mass Mass spectral analysis of A4 was carried out LC/MS on a Perkin-Elmer Sciex API-100 instrument, using the following conditions.
[0000] LC: Reverse Phase HPLC analysis
[0137] Column: Monitor 5 μm C18 50×4.6 mm
[0138] Solvent A: 0.1% TFA in water
[0139] Solvent B: 0.1% TFA in 90% aqueous acetonitrile
[0140] Gradient: 0-100% B over 11.0 min
[0141] Flow rate: 1.5 mL/min
[0142] Wavelength: 214 nm and 254 nm
[0000] MS: Ion Source: Ionspray
[0143] Detection: Ion counting
[0144] Flow rate to the mass spectrometer: 300 μL/min after split from column
[0000] (1.5 mL/min).
[0145] The results are summarised in Table 7.
TABLE 7 Summary of MS data from LC/MS analysis of compound A4 Molecular Exact Internal ID Formula Mass (*EM) Observed Ions A4 C 22 H 22 F 6 N 4 O 2 488.16 489.2 [M + H] + *Based on most abundant isotope
[0146] The local maxima were indicated on the main peaks. (M+H), the protonated molecular ion, was observed, together with other ions, some of which were considered to be artifacts of the MS.
[0147] Sample A4 was purified by preparative LC/MS on a Nebula instrument with a Waters XTerraMS column (19×50 mm, 5 μm, C18), using the following gradient: 5% B to 95% B over 4 min at 20 ml/min:
[0000] 0 min 0% B
[0000] 1 min 5% B
[0000] 5 min 95% B
[0000] 6 min 95% B
[0000] System Equilibration
EXAMPLE 3
Synthesis of a Library of Guanidine Amide Compounds (Library M0003)
[0148] Library M0003 is a single compound library of 50 guanidine amides, in which there is one point of diversity. The scaffold for this library is illustrated in formula III
in which R 4 is derived from a primary amine. This represents a subset of formula I in which A is methylene, R 1 is amino, R 2 is absent, G is absent, R 3 is H and R 4 is derived from a primary amine. The library has been synthesised using 50 primary amines for the R 4 substituents. The purity, as estimated by RP-HPLC at 214 nm, of compounds from Library M0003 averages 78.3% and ranges from 0% to 91% (s.d.=12%), determined from analysis of all 50 compounds in the library.
Synthesis
[0149] The synthesis was based on a literature method, (Kearney et al., 1998) and is summarised in Reaction Scheme 3.
[0150] Fmoc-protected 4-aminophenylacetic acid was coupled on to PS Rink Lanterns (loading: 36 μmol) using DIC and HOBt. The Fmoc protecting group was then removed with piperidine/DMF. The resultant aniline was then treated with Fmoc-NCS, then Fmoc deprotected. The thiourea-functionalised Lanterns thus formed were then S-methylated with iodomethane. Subsequent reaction with 50 different primary amines followed by cleavage from the solid phase using 20% TFA/DCM afforded the 50 secondary guanidines comprising Library M0003.
[0000] (i) Preparation of the Fmoc-Protected 4-Aminophenylacetic Acid
[0151] A solution of 4-aminophenylacetic acid (5.0 g, 33.1 mmol) in warm DMF (35 mL) was prepared under nitrogen. The solution was then heated to 75° C., then FmocCl (4.24 g, 16.4 mmol) was added in 4 portions over 5 minutes. The resultant mixture was then stirred at 75° C. for 45 minutes. The solution was cooled to room temperature, then a solution of 1M HCl (100 mL) was added. The precipitate which formed was collected via vacuum filtration and washed with 3 portions of deionised water (2×50 mL, 1×100 mL). The solid collected was then vacuum dried overnight at 30° C., then for 2 h at 50° C. to yield Fmoc-4-aminophenylacetic acid (5.39 g; 44%) as a beige solid.
[0000] (ii) Coupling of the Fmoc-Protected 4-Aminophenylacetic Acid to Fmoc-Protected Rink PS Lanterns
[0152] 75 PS Rink D-series Lanterns (batch 1531, loading: 36 μmol) were Fmoc deprotected by double treatment with 20% piperidine/DMF for 40 min and 30 min respectively. The second piperidine solution was removed and the Lanterns washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0153] A solution of Fmoc-4-aminophenylacetic acid (0.098M), HOBt.H 2 O (0.12M) and DIC (0.2M) in 20% DMF/DCM was prepared. To this solution was added the Fmoc-deprotected Lanterns. The mixture was then gently agitated at room temperature for 21 h. At the completion of the reaction, the coupling solution was removed and the Lanterns washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min). The Lanterns were air-dried overnight.
[0154] The Fmoc group was then removed by treating the Lanterns with a solution of 20% piperidine/DMF at room temperature for 5 hours. Two Lanterns were subjected to a loading determination, the result for which was determined to be 33.9 μmol. The piperidine solution was removed and the Lanterns were washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0000] (iii) Reaction with Fmoc-NCS and Iodomethane
[0155] A solution of Fmoc-NCS (0.2M) in DCM was prepared (50 mL). The 75 Lanterns from step (ii) were added and allowed to stand at room temperature for 5 h. The reaction solution was then drained and the Lanterns were washed with DCM (3×10 min), DMF (3×10 min) and DCM (3×10 min). The Lanterns were vacuum dried overnight at 40° C.
[0156] The Lanterns were again Fmoc-deprotected with 20% piperidine/DMF for 2.5 h. The piperidine solution was drained and the Lanterns washed with DMF (3×10 min) and DCM (3×10 min). The Lanterns were vacuum dried overnight at 45° C.
[0157] A solution of iodomethane (0.2M) in DMF (distilled) was prepared (50 mL). The Fmoc-deprotected Lanterns were added and then the contents were gently agitated at room temperature for 1 hour. A second solution of iodomethane (0.2M) in DMF was prepared. The first iodomethane solution was drained and the second iodomethane solution added immediately to the Lanterns. The Lanterns were then gently agitated at room temperature for a further 45 min. The iodomethane solution was drained and the Lanterns washed with DMF (3×10 min) and DCM (3×10 min). The Lanterns were then vacuum dried overnight at 35° C.
[0000] (iv) Guanidine Formation
[0158] Fifty solutions of the corresponding primary amines in DMSO (AR Grade) were prepared (50×1.25 mL). The primary amines used are summarized in Table 8. All amines were made up to 2M except amine #61, 3,5-dichlorobenzylamine (1M). Amine #45 (2-bromobenzylamine.HCl) was used with 1 equivalent of NaOH (for neutralisation). One Lantern from step (iii) was then added to each amine solution. The reaction solutions containing amines 31, 32, 33, 34 and 64 were heated to 85° C. for 16 h, whilst the remaining 45 solutions were heated to 85° C. for 6 h. At the completion of the reactions, the amine solutions were removed and the Lanterns washed with DMSO (2×10 min), DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min). The Lanterns were air-dried overnight at room temperature.
[0000] (v) Cleavage from the Solid Phase
[0159] Stems were attached to each Lantern and each Stem/Lantern assembly mounted onto a backing plate for cleavage. The Lanterns were then cleaved using 0.75 mL per Lantern of 10% TFA (distilled)/DCM for 1 h using a 96 well Bio-Rad® tray format. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator (GeneVac). The samples were then dissolved in 90% MeCN/H 2 O (0.9 mL) for analysis.
[0160] Owing to the low yield of material obtained, the Lanterns were then re-cleaved using 0.75 mL of 20% TFA/DCM for 1 hour. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator. The dried samples were then dissolved in 90% MeCN/H 2 O for analysis. After it was determined that the sets of compounds cleaved from the Lanterns in the two cleavages were identical, the stocks were combined into a single plate. The solutions were then evaporated in vacuo. The samples were then re-dissolved in 90% MeCN/H 2 O and dispensed into a microtitre plate.
[0000] Analysis
[0161] All 50 compounds were analysed by reverse phase HPLC and electrospray mass spectrometry as described in Example 1. The results are summarised in Table 9. Compound M41698-32Y (r1m42) did not display the target molecular weight. However, this compound when subjected to amide hydrolysis conditions, as described in Example 4 below for Library M0004, afforded the corresponding acid in good purity.
TABLE 8 Summary of R 4 -group structures and details for library M0003 Fragment Reagent Tag R 4 Group Structure Reagent Name Tag r1m01 2,2-diphenylethylamine DAC005 r1m04 3,5- bis(trifluoromethyl)benzylamine DAD005 r1m05 2-(2-aminoethylamino)-5- nitropyridine DAG001 r1m07 4-fluorophenethylamine DAD023 r1m08 3,4-dichlorobenzylamine DAD024 r1m09 2-methylbenzylamine DAC009 r1m10 1-naphthalenemethylamine DAC004 r1m11 2-phenethylamine DAC006 r1m12 4- (trifluoromethyl)benzylamine DAD006 r1m13 1-amino-2-phenylpropane b-phenethylamine DAC008 r1m14 4-methoxybenzylamine DAD003 r1m16 2-fluorobenzylamine DAD004 r1m17 4-methylbenzylamine DAC007 r1m18 2-methoxybenzylamine DAD009 r1m20 benzylamine DAC003 r1m22 piperonylamine DAD002 r1m24 hexylamine DAA002 r1m25 isobutylamine DAA010 r1m26 (+/−)-tetrahydrofurfurylamine DAB010 r1m27 allylamine DAA005 r1m30 4-methoxyaniline DAF002 r1m31 5-amino-2-methoxypyridine DAG009 r1m32 5-aminoindan DAE003 r1m33 1,4-benzodioxan-6-amine DAE001 r1m34 aniline DAE004 r1m35 3-methoxyphenethylamine DAD001 r1m36 2-(2-chlorophenyl)ethylamine DAD013 r1m37 3,4-dimethoxyaniline DAF007 r1m38 2-methoxyethylamine DAB001 r1m39 2-methoxyphenethylamine DAD017 r1m40 2-(4-chlorophenyl)ethylamine DAD008 r1m42 1-(3-aminopropyl)imidazole DAG006 r1m43 ethylamine DAA012 r1m44 2,5-difluorobenzylamine DAD027 r1m45 2-bromobenzylamine DAD028 r1m46 2- (trifluoromethyl)benzylamine DAD029 r1m48 3,3-diphenylpropylamine DAC011 r1m51 3-ethoxypropylamine DAB021 r1m52 3-fluorophenethylamine DAD033 r1m53 4-chlorobenzylamine DAD034 r1m56 1-aminopentane DAA005 r1m57 3-aminopentane DAA019 r1m58 cyclohexylamine DAA001 r1m59 cyclopentylamine DAA006 r1m60 cyclohexanemethylamine r1m61 3,5-dichlorobenzylamine DAD036 r1m62 furfurylamine DAG005 r1m63 2-(aminoethyl)pyridine DAG002 r1m64 3,5-dimethoxyaniline DAF009 r1m65 3-(dimethylamino)propylamine DAA016
[0162]
TABLE 9
Summary of Analytical Results
Compound Identification
HPLC and LC-MS Data (214 nm)
Compound
Monoisotopic
Retention
Peak
Target
(MH) +
ID
R Group
FW
Time (min)
Area (%)
Found
Observed
M41698-1Y
r1m01
372
6.43
83.8
✓
373.4
M41698-2Y
r1m04
418
6.94
84.5
✓
419.1
M41698-3Y
r1m05
357
4.92
84.3
✓
357.9
M41698-4Y
r1m07
314
5.27
84.3
✓
315.1
M41698-5Y
r1m08
350
6.18
87.9
✓
350.9
M41698-6Y
r1m09
296
5.10
86.8
✓
297.3
M41698-7Y
r1m10
332
5.94
87.0
✓
333.1
M41698-8Y
r1m11
296
5.08
43.4
✓
297.0
M41698-9Y
r1m12
350
5.92
87.7
✓
351.2
M41698-10Y
r1m13
310
5.48
86.3
✓
311.0
M41698-11Y
r1m14
312
4.79
80.6
✓
313.1
M41698-12Y
r1m16
300
4.61
88.1
✓
301.2
M41698-13Y
r1m17
296
5.21
85.3
✓
297.1
M41698-14Y
r1m18
312
5.08
86.0
✓
313.1
M41698-15Y
r1m20
282
4.53
86.6
✓
282.9
M41698-16Y
r1m22
326
4.64
86.0
✓
327.1
M41698-17Y
r1m24
276
5.76
86.2
✓
277.0
M41698-18Y
r1m25
248
4.12
83.5
✓
249.1
M41698-19Y
r1m26
276
3.89
80.5
✓
277.0
M41698-20Y
r1m27
232
3.36
69.2
✓
233.2
M41698-21Y
r1m30
298
4.41
77.7
✓
299.1
M41698-22Y
r1m31
299
3.80
78.7
✓
300.2
M41698-23Y
r1m32
308
5.60
80.3
✓
309.1
M41698-24Y
r1m33
326
4.44
81.5
✓
327.0
M41698-25Y
r1m34
268
4.08
61.9
✓
269.0
M41698-26Y
r1m35
326
5.20
69.1
✓
327.0
M41698-27Y
r1m36
330
5.64
55.1
✓
331.0
M41698-28Y
r1m37
328
4.22
58.9
✓
328.9
M41698-29Y
r1m38
250
3.38
78.5
✓
251.0
M41698-30Y
r1m39
326
5.48
77.3
✓
327.0
M41698-31Y
r1m40
330
5.93
84.1
✓
330.9
M41698-32Y
r1m42
300
—
A —
M41698-33Y
r1m43
220
3.25
72.5
✓
221.2
M41698-34Y
r1m44
318
4.74
91.0
✓
319.0
M41698-35Y
r1m45
360
5.31
89.7
✓
350.9
M41698-36Y
r1m46
350
5.46
88.0
✓
351.1
M41698-37Y
r1m48
386
7.12
90.0
✓
387.2
M41698-38Y
r1m51
278
4.04
82.8
✓
279.1
M41698-39Y
r1m52
314
5.33
83.8
✓
315.1
M41698-40Y
r1m53
316
5.47
89.2
✓
317.0
M41698-41Y
r1m56
262
4.96
84.2
✓
263.1
M41698-42Y
r1m57
262
4.37
78.6
✓
263.1
M41698-43Y
r1m58
274
4.83
87.6
✓
275.1
M41698-44Y
r1m59
260
4.25
86.2
✓
261.1
M41698-45Y
r1m60
288
5.65
87.6
✓
289.2
M41698-46Y
r1m61
350
6.14
83.3
✓
350.9
M41698-47Y
r1m62
272
3.93
85.1
✓
273.0
M41698-48Y
r1m63
297
2.89
B 79.8
✓
298.2
M41698-49Y
r1m64
328
4.88
30.6
✓
329.0
M41698-50Y
r1m65
277
2.63
B 72.9
✓
278.0
A No target ion found, m/z 223 observed.
B Co-elution of m/z 223 with target.
EXAMPLE 4
Synthesis of a Library of Guanidine Acid Compounds (Library M0004)
[0163] Library M0004 is a single compound library of 50 guanidine acids, in which there is one point of diversity. The scaffold for this library is shown in formula IV
in which R 4 is derived from a primary amine. Thus this library represents a subset of compounds of formula I in which A is methylene, R 1 is hydroxyl, R 2 is absent, G is absent, R 3 is H and R 4 is derived from a primary amine. The library was synthesised using 50 different primary amines for the R 4 substituents. This library was derived from library M0003 by splitting the amide products derived from that library, then hydrolysing one set to the corresponding acids. The purity, as estimated by RP-HPLC at 214 nm, of compounds from Library M0004 averages 74.8%, and ranges from 13% to 90% (s.d.=18%) determined from analysis of all 50 compounds in the library.
Synthesis
[0164] The synthesis was based on a literature method (Kearney et al., 1980), and is summarised in Reaction Scheme 4.
[0165] Fmoc-protected 4-aminophenylacetic acid was coupled onto PS Rink Lanterns (loading: 36 μmol) using DIC and HOBt. The Fmoc protecting group was then removed with piperidine/DMF. The resultant aniline was then treated with Fmoc-NCS, then Fmoc deprotected. The thiourea-functionalised Lanterns formed were then S-methylated with iodomethane. Subsequent reaction with 50 different primary amines followed by cleavage from the solid phase using 20% TFA/DCM afforded the 50 primary amide secondary guanidines, which were hydrolysed by treatment with TFA/H 2 O to the corresponding acids comprising Library M0004.
(i) Preparation of the Fmoc-Protected 4-Aminophenylacetic Acid
[0166] A solution of 4-aminophenylacetic acid (5.0 g, 33.1 mmol) in warm DMF (35 mL) was prepared under nitrogen. The solution was heated to 75° C., then FmocCl (4.24 g, 16.4 mmol) was added in 4 portions over a 5 min period. The mixture was then stirred at 75° C. for 45 minutes, cooled to room temperature, and a solution of 1M HCl (100 mL) added. The precipitate which formed was collected via vacuum filtration and washed with 3 portions of deionised water (2×50 mL, 1×100 mL). The solid collected was then vacuum dried overnight at 30° C., then for 2 h at 50° C. to yield the title compound 5.39 g (44%) as a beige solid.
[0000] (ii) Coupling of the Fmoc-Protected 4-Aminophenylacetic Acid to Fmoc-Protected Rink PS Lanterns
[0167] 75 PS Rink D-series Lanterns (batch 1531, loading: 36 μmol) were Fmoc deprotected by double treatment with 20% piperidine/DMF for 40 min and 30 min respectively. The second piperidine solution was removed and the Lanterns washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0168] A solution of Fmoc-4-aminophenylacetic acid (0.098M), HOBt.H 2 O (0.12M) and DIC (0.2M) in 20% DMF/DCM was prepared. To this solution was added the Fmoc-deprotected Lanterns. The mixture was then gently agitated at room temperature for 21 h. At the completion of the reaction, the Lanterns were drained and washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min), then air-dried overnight.
[0169] The Fmoc group was removed by treating the Lanterns with a solution of 20% piperidine/DMF at room temperature for 5 hours. Two Lanterns were subjected to a loading evaluation test, the result for which was determined to be 33.9 mmol. The piperidine solution was removed and the Lanterns were washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0000] (iii) Reaction with Fmoc-NCS and Iodomethane
[0170] A solution of Fmoc-NCS (0.2M) in DCM was prepared (50 mL). The 75 Lanterns from step (ii) were added and allowed to stand at room temperature for 5 h. The reaction solution was then drained and the Lanterns were washed with DCM (3×10 min), DMF (3×10 min) and DCM (3×10 min). The Lanterns were vacuum dried overnight at 40° C.
[0171] The Lanterns were Fmoc-deprotected with 20% piperidine/DMF for 2.5 h. The piperidine solution was drained and the Lanterns washed with DMF (3×10 min) and DCM (3×10 min). The Lanterns were vacuum dried overnight at 45° C.
[0172] A solution of iodomethane (0.2M) in DMF (distilled) was prepared (50 mL). The Fmoc-deprotected Lanterns were added and then the contents were gently agitated at room temperature for 1 hour. A second solution of iodomethane (0.2M) in DMF was prepared. The first iodomethane solution was drained and the second iodomethane solution added immediately to the Lanterns. The Lanterns were then gently agitated at room temperature for a further 45 min. The iodomethane solution was drained and the Lanterns washed with DMF (3×10 min) and DCM (3×10 min). The Lanterns were then vacuum dried overnight at 35° C.
[0000] (iv) Guanidine Formation
[0173] Fifty solutions of the corresponding primary amines in DMSO (AR Grade) were prepared (50×1.25 mL). The primary amines used are summarised in Table 10.
TABLE 10 Summary of R4-group structures and details for library M0004 Fragment Reagent Tag R 4 Group Structure Reagent Name Tag R1m01 2,2-diphenylethylamine DAC005 R1m04 3,5-bis(trifluoromethyl)benzylamine DAD005 R1m05 2-(2-aminoethylamino)-5-nitropyridine DAG001 R1m07 4-fluorophenethylamine DAD023 R1m08 3,4-dichlorobenzylamine DAD024 R1m09 2-methylbenzylamine DAC009 R1m10 1-naphthalenemethylamine DAC004 R1m11 2-phenethylamine DAC006 R1m12 4-(trifluoromethyl)benzylamine DAD006 R1m13 1-amino-2-phenylpropane b-phenethylamine DAC008 R1m14 4-methoxybenzylamine DAD003 R1m16 2-fluorobenzylamine DAD004 R1m17 4-methylbenzylamine DAC007 R1m18 2-methoxybenzylamine DAD009 R1m20 benzylamine DAC003 R1m22 piperonylamine DAD002 R1m24 hexylamine DAA002 R1m25 isobutylamine DAA010 R1m26 (+/−)-tetrahydrofurfurylamine DAB010 R1m27 allylamine DAA005 R1m30 4-methoxyaniline DAF002 R1m31 5-amino-2-methoxypyridine DAG009 R1m32 5-aminoindan DAE003 R1m33 1,4-benzodioxan-6-amine DAE001 R1m34 aniline DAE004 R1m35 3-methoxyphenethylamine DAD001 R1m36 2-(2-chlorophenyl)ethylamine DAD013 R1m37 3,4-dimethoxyaniline DAF007 R1m38 2-methoxyethylamine DAB001 R1m39 2-methoxyphenethylamine DAD017 R1m40 2-(4-chlorophenyl)ethylamine DAD008 R1m42 1-(3-aminopropyl)imidazole DAG006 R1m43 ethylamine DAA012 R1m44 2,5-difluorobenzylamine DAD027 R1m45 2-bromobenzylamine DAD028 R1m46 2-(trifluoromethyl)benzylamine DAD029 R1m48 3,3-diphenylpropylamine DAC011 R1m51 3-ethoxypropylamine DAB021 R1m52 3-fluorophenethylamine DAD033 R1m53 4-chlorobenzylamine DAD034 R1m56 1-aminopentane DAA005 R1m57 3-aminopentane DAA019 R1m58 cyclohexylamine DAA001 R1m59 cyclopentylamine DAA006 R1m60 cyclohexanemethylamine DAA003 R1m61 3,5-dichlorobenzylamine DAD036 R1m62 furfurylamine DAG005 R1m63 2-(aminoethyl)pyridine DAG002 R1m64 3,5-dimethoxyaniline DAF009 R1m65 3-(dimethylamino)propylamine DAA016
[0174] All amines were made up to 2M except amine #61, 3,5-dichlorobenzylamine (1M). Amine #45 (2-bromobenzylamine.HCl) was used with an equivalent of NaOH (to neutralise the hydrochloride salt). A Lantern from step (iii) was then added to each of the 50 amine solutions. The reaction solutions containing amines 31, 32, 33, 34 and 64 were heated to 85° C. for 16 h, whilst the remaining 45 solutions were heated to 85° C. for 6 h. At the completion of the reactions, the Lanterns were drained and washed with DMSO (2×10 min), DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min). The Lanterns were then air-dried overnight at room temperature.
[0000] (v) Cleavage from the Solid Phase
[0175] Stems were attached to each Lantern and each Stem/Lantern assembly mounted onto a backing plate for cleavage. The Lanterns were then cleaved using 0.75 mL per Lantern of 10% TFA (distilled)/DCM for 1 h using a 96 well Bio-Rad® tray format. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator (GeneVac). The samples were then dissolved in 90% MeCN/H 2 O (0.9 mL) for analysis.
[0176] Owing to the low yield of material obtained, the Lanterns were then re-cleaved using 0.75 mL of 20% TFA/DCM for 1 h. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator. The dried samples were then dissolved in 90% MeCN/H 2 O for analysis. After it was determined that the sets of compounds cleaved from the Lanterns in the two cleavages were identical, the stocks were combined into a single plate. The solutions were then evaporated in vacuo.
[0000] (vi) Amide Hydrolysis
[0177] The amide products above were dissolved in 90% MeCN/H 2 O and half of the material in each well was dispensed into 50 new BioRad tubes and evaporated in vacuo. A solution of TFA/H 2 O 1:1 (900 μL) was dispensed into each well, the tubes were capped and heated to 42° C. for 115 h. The samples were then concentrated, redissolved in 90% MeCN/H 2 O and again concentrated then redissolved in 90% MeCN/H 2 O and dispensed into a VMG plate.
[0000] Analysis
[0178] All 50 compounds were analyzed by reverse phase HPLC and electrospray mass spectrometry, as described in Example 1. The results are summarised in Table 11.
TABLE 11 Summary of Analytical Results Compound Identification HPLC and LC/MS Data (214 nm) Compound Monoisotopic Retention Peak Target (MH) + ID R Group FW Time (min) Area (%) Found Observed M0040101 r1m01 373 7.01 87.2 ✓ 374.4 M0040102 r1m04 419 7.25 82.8 ✓ 420.2 M0040103 r1m05 358 5.21 86.0 ✓ 359.0 M0040104 r1m07 315 5.63 84.3 ✓ 315.9 M0040105 r1m08 351 6.41 88.0 ✓ 352.0 M0040106 r1m09 297 5.46 87.6 ✓ 298.2 M0040107 r1m10 333 6.25 82.6 ✓ 334.2 M0040108 r1m11 297 5.52 46.6 ✓ 298.5 M0040109 r1m12 351 6.24 87.3 ✓ 352.1 M0040110 r1m13 311 5.86 86.0 ✓ 312.1 M0040111 r1m14 313 5.31 12.9 ✓ 314.3 M0040112 r1m16 301 5.07 87.4 ✓ 302.2 M0040113 r1m17 297 5.59 85.8 ✓ 298.3 M0040114 r1m18 313 5.45 79.4 ✓ 313.9 M0040115 r1m20 283 4.98 86.1 ✓ 284.3 M0040116 r1m22 327 5.12 42.3 ✓ 328.1 M0040117 r1m24 277 6.14 82.8 ✓ 278.0 M0040118 r1m25 249 4.57 83.5 ✓ 249.9 M0040119 r1m26 277 4.25 78.1 ✓ 277.9 M0040120 r1m27 233 3.75 72.5 ✓ 233.9 M0040121 r1m30 299 4.78 72.7 ✓ 300.2 M0040122 r1m31 300 4.24 62.8 ✓ 301.2 M0040123 r1m32 309 6.03 85.0 ✓ 309.9 M0040124 r1m33 327 4.85 86.9 ✓ 328.0 M0040125 r1m34 269 4.48 53.1 ✓ 270.3 M0040126 r1m35 327 5.65 62.4 ✓ 328.3 M0040127 r1m36 331 6.06 51.3 ✓ 331.8 M0040128 r1m37 329 4.60 55.5 ✓ 330.0 M0040129 r1m38 251 3.79 80.8 ✓ 252.0 M0040130 r1m39 327 5.87 73.3 ✓ 328.2 M0040131 r1m40 331 6.26 82.8 ✓ 332.3 M0040132 r1m42 301 2.98 89.8 ✓ 302.0 M0040133 r1m43 221 3.63 73.7 ✓ 222.4 M0040134 r1m44 319 5.15 86.2 ✓ 320.1 M0040135 r1m45 361 5.68 89.1 ✓ 361.9 M0040136 r1m46 351 5.94 86.8 ✓ 352.0 M0040137 r1m48 387 7.52 88.4 ✓ 388.2 M0040138 r1m51 279 4.49 81.7 ✓ 280.3 M0040139 r1m52 315 5.66 79.2 ✓ 316.0 M0040140 r1m53 317 5.80 87.0 ✓ 318.1 M0040141 r1m56 263 5.41 82.5 ✓ 264.1 M0040142 r1m57 263 4.82 67.9 ✓ 264.4 M0040143 r1m58 275 5.20 79.1 ✓ 276.3 M0040144 r1m59 261 4.69 81.8 ✓ 262.0 M0040145 r1m60 289 6.03 85.1 ✓ 290.1 M0040146 r1m61 351 6.42 75.4 ✓ 352.1 M0040147 r1m62 273 4.41 14.5 ✓ 273.9 M0040148 r1m63 298 3.05 A 85.1 ✓ 299.4 M0040149 r1m64 329 5.30 32.1 ✓ 330.2 M0040150 r1m65 278 2.71 B 79.3 ✓ 278.9 A Co-elution of m/z 404.2 with target ion. B Co-elution of m/z 364.3 with target ion.
[0179] All compounds displayed the target molecular weight. The LC/MS results indicated that at least two ions were detected under each major peak. These are and (MH+122) + . Additionally, there were ions corresponding to [MH+(n×222)] + , where n is an integer. An ion of m/z 222 was also detected in the buffer solution of the instrument.
EXAMPLE 5
Synthesis of a Library of Tertiary Guanidine Amide Compounds (Library M0007)
[0180] Library M0007 is a single compound library of 21 tertiary guanidine amides. The scaffold for this library is illustrated in formula V, in which both R 3 and R 4 are derived from primary amines, which may be the same or different.
[0181] Thus this represents a subset of formula I in which A is methylene, R 1 is amino, R 2 is absent, G is absent, R 3 and R 4 are derived from a primary amine.
[0182] The library was synthesised using 21 different primary amines for the R 3 and R 4 substituents. The purity, as estimated by RP-HPLC at 214 nm, of compounds from Library M0007 averages 85.6%, and ranges from 73% to 92% (s.d.=5.5%), determined from analysis of all 21 compounds in the library.
[0183] The compounds were plated on the basis of 3.8 mg relative to the average mass obtained for the complete set of 21 compounds. The amount of compound per well was 8.8 μmol, based on an average molecular weight of 431 amu.
[0000] Synthesis
[0184] The synthesis is summarised in Reaction Scheme 5. Fmoc-protected 4-aminophenylacetic acid was coupled onto PS Rink Lanterns (loading: 36 μmol) using DIC and HOBt. The Fmoc protecting group was then removed with piperidine/DMF. The resultant aniline was then treated with Fmoc-NCS, then Fmoc deprotected. The thiourea functionalised Lanterns formed were then S-methylated with iodomethane. Subsequent reaction with 21 different primary amines followed by cleavage from the solid phase using 20% TFA/DCM afforded the 21 tertiary guanidines comprising Library M0007.
(i) Preparation of the Fmoc-Protected 4-Aminophenylacetic Acid
[0185] A solution of 4-aminophenylacetic acid (5.0 g, 33.1 mmol) in warm DMF (35 mL) was prepared under N 2 . The solution was then heated to 75° C., and FmocCl (4.24 g, 16.4 mmol) was added in 4 portions over 5 minutes. The resultant mixture was then stirred at 75° C. for 45 minutes. The solution was cooled to room temperature, then a solution of 1M HCl (100 mL) was added. The precipitate which formed was collected via vacuum filtration and washed with 3 portions of deionised water (2×50 mL, 1×100 mL). The solid collected was then vacuum dried overnight at 30° C., then for 2 h at 50° C. to yield Fmoc-4-aminophenylacetic acid (5.39 g; 44%) as a beige solid.
[0000] (ii) Coupling of the Fmoc-Protected 4-Aminophenylacetic Acid to Fmoc-Protected Rink PS Lanterns
[0186] 50 PS Rink D-series Lanterns (batch 1531, loading: 36 μmol) were Fmoc deprotected by double treatment with 20% piperidine/DMF for 40 min and 30 min. The second piperidine solution was removed and the Lanterns were washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0187] A solution of Fmoc-4-aminophenylacetic acid (0.098M), HOBt.H 2 O (0.12M) and DIC (0.2M) in 20% DMF/DCM was prepared. To this solution was added the Fmoc-deprotected Lanterns. The mixture was then gently agitated at room temperature for 21 h. At the completion of the reaction, the coupling solution was removed and the Lanterns washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min). The Lanterns were air-dried overnight.
[0188] The Fmoc group was then removed by treating the Lanterns with a solution of 20% piperidine/DMF at room temperature for 5 hours. Two Lanterns were subjected to a loading determination, result: 33.9 μmmol (average). The piperidine solution was removed and the Lanterns were washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0000] (iii) Reaction with Fmoc-NCS and Iodomethane
[0189] A solution of Fmoc-NCS (0.2M) in DCM was prepared. The Lanterns from step (ii) were added to this solution and allowed to stand at room temperature for 5 h. The reaction solution was then drained and the Lanterns were washed with DCM (3×10 min), DMF (3×10 min) and DCM (3×10 min). The Lanterns were vacuum dried overnight at 40° C.
[0190] The Lanterns were again Fmoc-deprotected, with 20% piperidine/DMF for 2.5 h. The piperidine solution was drained and the Lanterns washed with DMF (3×10 min) and DCM (3×10 min). The Lanterns were vacuum dried overnight at 45° C.
[0191] A solution of iodomethane (0.2M) in DMF (distilled) was prepared. The Fmoc-deprotected Lanterns were added and then the contents were gently agitated at room temperature for 1 hour. A second solution of iodomethane (0.2M) in DMF was prepared. The first iodomethane solution was drained and the second iodomethane solution added immediately to the Lanterns. The Lanterns were then gently agitated at room temperature for a further 45 min. The iodomethane solution was drained and the Lanterns washed with DMF (3×10 min) and DCM (3×10 min). The Lanterns were then vacuum dried overnight at 35° C.
[0000] (iv) Tertiary Guanidine Formation
[0192] Solutions (4M) of the primary amines in DMSO (AR Grade) were prepared (1.25 mL). The amines used are summarized in Table 12. One Lantern from step (iii) was then added to each amine solution. The reaction solutions were heated to 100° C. for 111 h. At the completion of the reactions, the amine solutions were removed and the Lanterns washed with DMSO (2×10 min), DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min). The Lanterns were air-dried overnight at room temperature.
[0000] (v) Cleavage from the Solid Phase
[0193] Cleavage Stems were manually attached to each Lantern and each Stem/Lantern assembly mounted onto a backing plate for cleavage. The Lanterns were then cleaved using 0.75 mL per Lantern of 10% TFA (distilled)/DCM for 1 h using a 96 well Bio-Rad® tray format. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator (GeneVac). The samples were then dissolved in 90% MeCN/H 2 O (0.9 mL) for analysis.
[0194] Since the Lanterns had been inadvertedly cleaved with 10% TFA/DCM instead of 20% TFA/DCM, the Lanterns were then re-cleaved using 0.75 mL of 20% TFA/DCM for 1 hour. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator. The dried samples were then dissolved in 90% MeCN/H 2 O for analysis. After it was determined that the sets of compounds cleaved from the Lanterns in the two cleavages were essentially identical, the stocks were combined into a single plate. The solutions were then evaporated in vacuo. The samples were then re-dissolved in 90% MeCN/H 2 O, re-analysed and dispensed into a microtitre plate.
[0000] Analysis
[0195] All 21 compounds were analysed by reverse phase HPLC and electrospray mass spectrometry as described in Example 1. All compounds displayed the target molecular weight. The results are summarised in Table 13.
TABLE 12 Summary of R 3 and R 4 group structures and details for library M0007 Fragment Reagent Tag R 3 and R 4 Group Structure Reagent Name Tag r1m01 2,2-diphenylethylamine DAC005 r1m04 3,5- bis(trifluoromethyl)benzylamine DAD008 r1m07 4-fluorophenethylamine DAD023 r1m08 3,4-dichlorobenzylamine DAD024 r1m09 2-methylbenzylamine DAC009 r1m10 1-naphthalenemethylamine DAC004 r1m11 2-phenethylamine DAC006 r1m12 4-(trifluoromethyl)benzylamine DAD006 r1m13 1-amino-2-phenylpropane (beta-phenethylamine) DAC008 r1m14 4-methoxybenzylamine DAD003 r1m16 2-fluorobenzylamine DAD004 r1m17 4-methylbenzylamine DAC007 r1m18 2-methoxybenzylamine DAD009 r1m20 benzylamine DAC003 r1m22 piperonylamine DAD002 r1m24 hexylamine DAA002 r1m25 isobutylamine DAA010 r1m26 (+/−)-tetrahydrofurfurylamine DAB010 r1m27 allylamine DAA005 r1m40 2-(4-chlorophenyl)ethylamine DAD008 r1m44 2,5-difluorobenzylamine DAD027
[0196]
TABLE 13
Summary of Analytical Results: Library M0007
Compound Identification
HPLC and LC-MS Data (214 nm)
Compound
Monoisotopic
Retention
Peak
Target
(MH)+
ID
R Group
FW
Time (min)
Area (%)
Found
Observed
M41697-1Z
r1m01-r2m01
552
9.69
A 92.0
✓
553.2
M41697-2Z
r1m04-r2m04
644
9.90
83.5
✓
645.3
M41697-4Z
r1m07-r2m07
436
7.53
91.9
✓
437.1
M41697-5Z
r1m08-r2m08
508
8.94
83.7
✓
B 509.3
M41697-6Z
r1m09-r2m09
400
7.62
89.6
✓
401.2
M41697-7Z
r1m10-r2m10
472
8.73
86.2
✓
473.1
M41697-8Z
r1m11-r2m11
400
7.41
73.1
✓
401.3
M41697-9Z
r1m12-r2m12
508
8.59
83.8
✓
509.3
M41697-10Z
r1m13-r2m13
428
8.04
90.3
✓
429.2
M41697-11Z
r1m14-r2m14
432
6.68
86.8
✓
433.3
M41697-12Z
r1m16-r2m16
408
6.75
83.6
✓
409.0
M41697-13Z
r1m17-r2m17
400
7.82
89.8
✓
401.4
M41697-14Z
r1m18-r2m18
432
7.52
89.0
✓
433.1
M41697-15Z
r1m20-r2m20
372
6.67
89.6
✓
373.1
M41697-16Z
r1m22-r2m22
460
6.50
A 86.2
✓
461.1
M41697-17Z
r1m24-r2m24
360
9.00
89.2
✓
361.2
M41697-18Z
r1m25-r2m25
304
5.95
90.8
✓
305.2
M41697-19Z
r1m26-r2m26
360
5.16
85.4
✓
361.1
M41697-20Z
r1m27-r2m27
272
4.14
72.8
✓
273.1
M41697-31Z
r1m40-r2m40
468
8.56
86.1
✓
B 469.1
M41697-34Z
r1m44-r2m44
444
6.92
78.1
✓
445.0
A Analysis of unpooled second cleavage product; compounds M41697-1X and M41697-16X respectively.
B Correct isotope pattern observed.
EXAMPLE 6
Synthesis of a Second Library of Tertiary Guanidine Acid Compounds (Library M0008)
[0197] Library M0008 is a single compound library of 21 tertiary guanidine amides. The scaffold for this library is shown in formula VI
in which R 3 is the same as R 4 , and is derived from a primary amine. Thus these compounds represent a subset of formula I in which A is methylene, R 1 is hydroxyl, R 2 is absent, G is absent, R 3 and R 4 are derived from a primary amine.
[0198] The library was synthesised using 21 primary amines for the R 3 and R 4 substituents. This library was derived from library M0007 by splitting the amide products derived from that library, then hydrolysing one set to the corresponding acids. The purity (as estimated by RP-HPLC at 214 nm) of compounds in Library M0008 averages 85.0%, and ranges from 68% to 92% (s.d.=6.2%), determined from analysis of all 21 compounds in the library.
[0199] The compounds were plated on the basis of 4.8 mg relative to the average mass obtained for the complete set of 21 compounds. The amount of compound per well was 11 μmol, based on an average molecular weight of 432 amu.
[0000] Synthesis
[0200] The synthesis is summarized in Reaction Scheme 6. Fmoc-protected 4-aminophenylacetic acid was coupled on to PS Rink Lanterns (loading: 36 μmol) using DIC and HOBt. The Fmoc protecting group was then removed with piperidine/DMF. The resultant aniline was then treated with Fmoc-NCS, then Fmoc deprotected. The thiourea functionalised Lanterns formed were then S-methylated with iodomethane. Subsequent reaction with 21 different primary amines followed by cleavage from the solid phase using 20% TFA/DCM afforded the 21 tertiary guanidines comprising Library M0008.
(i) Preparation of the Fmoc-Protected 4-Aminophenylacetic Acid
[0201] A solution of 4-aminophenylacetic acid (5.0 g, 33.1 mmol) in warm DMF (35 mL) was prepared under N 2 . The solution was then heated to 75° C., and FmocCl (4.24 g, 16.4 mmol) was added in 4 portions over 5 minutes. The resultant mixture was then stirred at 75° C. for 45 minutes. The solution was cooled to room temperature, then a solution of 1M HCl (100 mL) was added. The precipitate which formed was collected via vacuum filtration and washed with 3 portions of deionised water (2×50 mL, 1×100 mL). The solid collected was then vacuum dried overnight at 30° C., then for 2 h at 50° C. to yield Fmoc-4-aminophenylacetic acid (5.39 g; 44%) as a beige solid.
[0000] (ii) Coupling of the Fmoc-Protected 4-Aminophenylacetic Acid to Fmoc-Protected Rink PS Lanterns
[0202] 50 PS Rink D-series Lanterns (batch 1531, loading: 36 μmol) were Fmoc deprotected by double treatment with 20% piperidine/DMF for 40 min and 30 min respectively. The second piperidine solution was removed and the Lanterns washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0203] A solution of Fmoc-4-aminophenylacetic acid (0.098M), HOBt.H 2 O (0.12M) and DIC (0.2M) in 20% DMF/DCM was prepared. To this solution was added the Fmoc-deprotected Lanterns. The mixture was then gently agitated at room temperature for 21 h. At the completion of the reaction, the coupling solution was removed and the Lanterns washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min). The Lanterns were air-dried overnight.
[0204] The Fmoc group was then removed by treating the Lanterns with a solution of 20% piperidine/DMF at room temperature for 5 hours. Two Lanterns were subjected to a loading determination, result: 33.9 μmol (average). The piperidine solution was removed and the Lanterns were washed with DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min).
[0000] (iii) Reaction with Fmoc-NCS and Iodomethane
[0205] A solution of Fmoc-NCS (0.2M) in DCM was prepared. The Lanterns from step (ii) were added to this solution and allowed to stand at room temperature for 5 h. The reaction solution was then drained and the Lanterns were washed with DCM (3×10 min), DMF (3×10 min) and DCM (3×10 min). The Lanterns were vacuum dried overnight at 40° C.
[0206] The Lanterns were again Fmoc-deprotected, with 20% piperidine/DMF for 2.5 h. The piperidine solution was drained and the Lanterns washed with DMF (3×10 min) and DCM (3×10 min). The Lanterns were vacuum dried overnight at 45° C.
[0207] A solution of iodomethane (0.2M) in DMF (distilled) was prepared. The Fmoc-deprotected Lanterns were added and then the contents were gently agitated at room temperature for 1 hour. A second solution of iodomethane (0.2M) in DMF was prepared. The first iodomethane solution was drained and the second iodomethane solution added immediately to the Lanterns. The Lanterns were then gently agitated at room temperature for a further 45 min. The iodomethane solution was drained and the Lanterns washed with DMF (3×10 min) and DCM (3×10 min). The Lanterns were then vacuum dried overnight at 35° C.
[0000] (iv) Tertiary Guanidine Formation
[0208] Solutions (4M) of the primary amines in DMSO (AR Grade) were prepared (1.25 mL). The primary amines used are summarized in Table 14. One Lantern from step (iii) was then added to each amine solution. The reaction solutions were heated to 100° C. for 111 h. At the completion of the reactions, the amine solutions were removed and the Lanterns washed with DMSO (2×10 min), DMF (3×10 min), 50% DMF/DCM (3×10 min) and DCM (3×10 min). The Lanterns were air-dried overnight at room temperature.
[0000] (v) Cleavage from the Solid Phase
[0209] Cleavage Stems were manually attached to each Lantern and each Stem/Lantern assembly mounted onto a backing plate for cleavage. The Lanterns were then cleaved using 0.75 mL per Lantern of 10% TFA (distilled)/DCM for 1 h using a 96 well Bio-Rad® tray format. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator (GeneVac). The samples were then dissolved in 90% MeCN/H 2 O (0.9 mL) for analysis.
[0210] Since the Lanterns had been inadvertedly cleaved with 10% TFA/DCM instead of 20% TFA/DCM, the Lanterns were then re-cleaved using 0.75 mL of 20% TFA/DCM for 1 hour. The resulting cleavage solutions were evaporated in vacuo using a centrifugal evaporator. The dried samples were then dissolved in 90% MeCN/H 2 O for analysis. After it was determined that the sets of compounds cleaved from the Lanterns in the two cleavages were essentially identical, the stocks were combined into a single plate. The solutions were then evaporated in vacuo. The samples were then re-dissolved in 90% MeCN/H 2 O and re-analysed, then concentrated.
[0000] (vi) Amide Hydrolysis
[0211] The amide products above were dissolved in 90% MeCN/H 2 O an half of each solution was dispensed into new BioRad® tubes and evaporated in vacuo. A solution of TFA/H 2 O 1:1 (900 μL) was dispensed into each well, the tubes were capped, a heavy metal plate was placed on top of the capped tubes to keep the caps in place, and the tubes were heated to 40° C. for 120 h. The samples were then concentrated, redissolved in 90% MeCN/H 2 O and analysed, then concentrated and redissolved in 90% MeCN/H 2 O, then dispensed into a microtitre plate.
[0000] Analysis
[0212] All 21 compounds were analysed by reverse phase HPLC and electrospray mass spectrometry as described in Example 1. All compounds displayed the target molecular weight. A minor peak (ca. 3-5%), due to the presence of the corresponding starting amide was observed in most cases, indicating incomplete hydrolysis. The results are summarized in Table 15.
TABLE 14 Summary of R 3 and R 4 group structures and details for library M0008 Fragment Reagent Tag R 3 and R 4 Group Structure Reagent Name Tag R1m01 2,2-diphenylethylamine DAC005 R1m04 3,5- bis(trifluoromethyl)benzylamine DAD008 R1m07 4-fluorophenethylamine DAD023 R1m08 3,4-dichlorobenzylamine DAD024 R1m09 2-methylbenzylamine DAC009 R1m10 1-naphthalenemethylamine DAC004 R1m11 2-phenethylamine DAC006 R1m12 4-(trif1uoromethyl)benzylamine DAD006 R1m13 1-amino-2-phenylpropane (beta-phenethylamine) DAC008 R1m14 4-methoxybenzylamine DAD003 R1m16 2-fluorobenzylamine DAD004 R1m17 4-methylbenzylamine DAC007 R1m18 2-methoxybenzylamine DAD009 R1m20 benzylamine DAC003 R1m22 piperonylamine DAD002 R1m24 hexylamine DAA002 R1m25 isobutylamine DAA010 R1m26 (+/−)-tetrahydrofurfurylamine DAB010 R1m27 allylamine DAA005 R1m40 2-(4-chlorophenyl)ethylamine DAD008 R1m44 2,5-difluorobenzylamine DAD027
[0213]
TABLE 15
Summary of Analytical Results: Library M0008
Compound
HPLC and LC-
Identification
MS Data (214 nm)
Compound
Monoisotopic
Retention
Peak
Target
(MH) +
ID
R Group
FW
Time (min)
Area (%)
Found
Observed
M4170016-1
r1m01-r2m01
553
10.41
91.1
✓
554.4
M4170016-2
r1m04-r2m04
645
10.43
85.5
✓
646.4
M4170016-4
r1m07-r2m07
437
8.12
91.3
✓
438.1
M4170016-5
r1m08-r2m08
509
9.48
85.0
✓
A 510.0
M4170016-6
r1m09-r2m09
401
8.24
89.6
✓
402.4
M4170016-7
r1m10-r2m10
473
9.28
88.1
✓
474.3
M4170016-8
r1m11-r2m11
401
8.00
67.6
✓
402.5
M4170016-9
r1m12-r2m12
509
9.11
85.6
✓
510.1
M4170016-10
r1m13-r2m13
429
8.67
86.8
✓
430.4
M4170016-11
r1m14-r2m14
433
7.34
73.6
✓
434.4
M4170016-12
r1m16-r2m16
409
7.37
82.7
✓
410.2
M4170016-13
r1m17-r2m17
401
8.40
87.8
✓
402.3
M4170016-14
r1m18-r2m18
433
8.12
87.0
✓
434.3
M4170016-15
r1m20-r2m20
373
7.30
86.4
✓
374.4
M4170016-16
r1m22-r2m22
461
7.02
82.6
✓
462.1
M4170016-17
r1m24-r2m24
361
9.60
92.3
✓
362.2
M4170016-18
r1m25-r2m25
305
6.62
88.4
✓
306.0
M4170016-19
r1m26-r2m26
361
5.74
90.8
✓
362.3
M4170016-20
r1m27-r2m27
273
4.74
76.1
✓
274.1
M4170016-31
r1m40-r2m40
469
9.05
86.4
✓
A 470.1
M4170016-34
r1m44-r2m44
445
7.52
80.7
✓
446.0
A Correct isotope pattern observed.
EXAMPLE 7
Synthesis of Tertiary Guanidine Amide Compound: 4-[N′-Cyclohexylmethyl-N″-(2-methyl-benzyl)-guanidino]-3-(2-phenoxy-ethoxy)-benzamide
[0214] The synthesis is summarised in Reaction Scheme 1.
[0215] In Reaction Scheme 7: (i) DIC, DMAP, CH 2 Cl 2 , room temperature, 16 h; (ii) KH, DMF, 100° C., 24 h; (iii) SnCl 2 .2H 2 O, DMF, room temperature, 24 h; (iv) FmocNCS, CH 2 Cl 2 , room temperature, 7 h; (v) 20% piperidine/DMF, room temperature, 40 min, 1 h 20 min, then CH 3 I, DMF, 40 min ×2; (vi) 2-methylbenzylamine, DMSO, 75-85° C., 9 h; (vii) cyclohexylmethylamine, DMSO, 100° C., 4 days; (viii) 20%. TFA/CH 2 Cl 2 , room temperature, 1 h.
[0000] Synthetic Step (I)
[0216] 100 PS-D-RAM SynPhase™ Lanterns (batch 1703-13A, loading capacity 35 μmol) with Rink amide linker attached were Fmoc-deprotected using a solution of premixed 20% piperidine/DMF (v/v) (2×40 min). The piperidine solution was filtered off and the Lanterns washed with DMF (5×20 min) and CH 2 Cl 2 (2×10 min)
[0217] 80 mL of a solution of 3-hydroxy-4-nitrobenzoic acid (0.2M), DIC (0.1M) and DMAP (0.05M) in CH 2 Cl 2 was prepared. The solution was allowed to stand at room temperature for 3 min then was added to the Fmoc-deprotected Lanterns. The Lanterns were stood at room temperature for 16 h. The reaction solution was then drained and the Lanterns washed with CH 2 Cl 2 (4×20 min), DMF (8×20 min). Concomitantly-formed esters were then cleaved using alternate solutions of 10% ethanolamine/DMF (v/v) (15 min) and DMF (10 min) until clear spent washing solutions were obtained—approximately 6 cycles. The Lanterns were then washed with 50% CH 3 COOH/CH 2 Cl 2 (v/v) (2×10 min) then CH 2 Cl 2 (3×10 min) and vacuum dried at 40° C. for 1 hour.
[0000] Synthetic Step (ii)
[0218] The Lanterns from step (i), 56 in total were subjected to treatments with a slurry of excess potassium hydride (freshly extracted with petroleum ether from mineral oil) in anhydrous DMF for 30 min and 5 min respectively.
[0219] 40 mL of a solution of 2-phenoxyethyl bromide (1.0M) and Cs 2 CO 3 (0.3M) in anhydrous DMF was prepared. The KH-treated Lanterns were then added to this reaction solution and left to stand at 100° C. for 24 h. The reaction solution was drained and the Lanterns transferred to a clean vessel. The Lanterns were washed with DMF (3×10 min), 50% DMF/H 2 O (v/v) (2×30 min), DMF (2×10 min) and CH 2 Cl 2 (4×10 min) then vacuum dried at 40° C. for 1 hour.
[0000] Synthetic Step (iii)
[0220] 34 mL of a solution of tin(II)chloride dihydrate (1M) in DMF (distilled grade) was prepared. This solution was then added to the Lanterns from step (ii) and stood at room temperature for 24 h. The reaction solution was drained and the Lanterns washed with DMF (2×5 min), 20% H 2 O/THF (2×30 min, 1×15 min), THF (1×15 min) and CH 2 Cl 2 (4×15 min) then air dried overnight.
[0000] Synthetic Step (iv)
[0221] 34 mL of a solution of FmocNCS (0.2M) in CH 2 Cl 2 was prepared. The reaction solution was added to 50 Lanterns from step (iii) and the Lanterns stood at room temperature for 6.5 h, then heated to 40° C. for the final 0.5 h (total of 7 h reaction time). At the conclusion of the reaction, the FmocNCS solution was drained and the Lanterns washed with CH 2 Cl 2 (4×10 min), DMF (2×10 min). These Lanterns were taken immediately to step (v).
[0000] Synthetic Step (v)
[0222] The Lanterns were firstly treated with 20% piperidine/DMF (v/v) at room temperature (2 treatments of 40 min and 1 h 20 min respectively; there were no washes in between treatments). The second piperidine solution was drained and the Lanterns washed with DMF (4×10 min). The lanterns were further reacted immediately.
[0223] A solution of iodomethane (0.2M) in DMF was prepared and added to the Fmoc-deprotected Lanterns. The Lanterns were allowed to stand at room temperature for 40 min. The iodomethane solution was then removed and the Lanterns subjected to a second solution of iodomethane (0.2M) in DMF for 40 min; there were no washes in between treatments. After the 40 min was complete, the reaction solution was drained and the Lanterns washed with DMF (5×10 min) and DMSO (1×10 min). The Lanterns were taken immediately to step (vi).
[0000] Synthetic Step (vi)
[0224] Four Lanterns from step (v) were added to a solution of 2-methylbenzylamine (2.0M) in DMSO then placed in an oven set to 85° C. for 6 h. At the completion of the reaction, the amine solution was drained and the Lanterns washed with hot (85° C.) DMSO (2×10 min, 2×30 min), DMF (3×10 min) and CH 2 Cl 2 (3×20 min). The Lanterns were then air dried overnight.
[0000] Synthetic Step (vii)
[0225] Two Lanterns were then added to a solution of cyclohexylmethylamine (1.0M) in DMSO then placed in an oven set to 100° C. for 4 days. At the completion of the reaction, the amine solution was drained and the Lanterns washed with hot (85° C.) DMSO (2×10 min, 2×30 min), DMF (3×10 min) and CH 2 Cl 2 (3×20 min). The Lanterns were then air dried overnight.
[0000] Synthetic Step (viii)
[0226] The Lanterns were cleaved using a solution of 20% TFA/CH 2 Cl 2 (v/v). The Lanterns were stood at room temperature for 1 h. The solution was evaporated under reduced pressure to give an oil. The oil was dissolved in 90% MeCN/H 2 O. The required tertiary guanidine was identified by analytical LCMS (purity=14%).
EXAMPLE 8
Synthesis of Tertiary Guanidine Amide Compound: 3-Benzyloxy-4-[N′-cyclohexylmethyl-N″-(2-methyl-benzyl)-guanidino]-benzamide
[0227] The synthesis is summarised in Reaction Scheme 8.
[0228] In Reaction Scheme 1: (i) DIC, DMAP, CH 2 Cl 2 , room temperature, 16 h; (ii) benzylbromide, KH, DMF, 40° C., 24 h; (iii) SnCl 2 .2H 2 O, DMF, room temperature, 24 h; (iv) FmocNCS, CH 2 Cl 2 , room temperature, 7 h; (v) 20% piperidine/DMF, room temperature, 40 min, 1 h 20 min, then CH 3 I, DMF, 40 min ×2; (vi) 2-methylbenzylamine, DMSO, 75-85° C., 9 h; (vii) cyclohexylmethylamine, DMSO, 100° C., 4 days; (viii) 20% TFA/CH 2 Cl 2 , room temperature, 1 h.
[0000] Synthetic Step (I)
[0229] 100 PS-D-RAM SynPhase™ Lanterns (batch 1703-13A, loading capacity 35 μmol) with Rink amide linker attached were Fmoc-deprotected using a solution of premixed 20% piperidine/DMF (v/v) (2×40 min). The piperidine solution was filtered off and the Lanterns washed with DMF (5×20 min) and CH 2 Cl 2 (2×10 min).
[0230] 80 mL of a solution of 3-hydroxy-4-nitrobenzoic acid (0.2M), DIC (0.1M) and DMAP (0.05M) in CH 2 Cl 2 was prepared. The solution was allowed to stand at room temperature for 3 min then was added to the Fmoc-deprotected Lanterns. The Lanterns were stood at room temperature for 16 h. The reaction solution was then drained and the Lanterns washed with CH 2 Cl 2 (4×20 min), DMF (8×20 min). Concomitantly-formed esters were then cleaved using alternate solutions of 10% ethanolamine/DMF (v/v) (15 min) and DMF (10 min) until clear spent washing solutions were obtained—approximately 6 cycles. The Lanterns were then washed with 50% CH 3 COOH/CH 2 Cl 2 (v/v) (2×10 min) then CH 2 Cl 2 (3×10 min) and vacuum dried at 40° C. for 1 hour.
[0000] Synthetic Step (ii)
[0231] The Lanterns from step (i), 56 in total were subjected to treatments with a slurry of excess potassium hydride (freshly extracted with petroleum ether from mineral oil) in anhydrous DMF for 30 min and 5 min respectively.
[0232] 40 mL of a solution of benzyl bromide (1.0M) and Cs 2 CO 3 (0.3M) in anhydrous DMF was prepared. The KH-treated Lanterns were then added to this reaction solution and left to stand at 40° C. for 24 h. The reaction solution was drained and the Lanterns transferred to a clean vessel. The Lanterns were washed with DMF (3×10 min), 50% DMF/H 2 O (v/v) (2×30 min), DMF (2×10 min) and CH 2 Cl 2 (4×10 min) then vacuum dried at 40° C. for 1 hour.
[0000] Synthetic Step (iii)
[0233] 34 mL of a solution of tin(II)chloride dihydrate (1M) in DMF (distilled grade) was prepared. This solution was then added to the Lanterns from step (ii) and stood at room temperature for 24 h. The reaction solution was drained and the Lanterns washed with DMF (2×5 min), 20% H 2 O/THF (2×30 min, 1×15 min), THF (1×15 min) and CH 2 Cl 2 (4×15 min) then air dried overnight.
[0000] Synthetic Step (iv)
[0234] 34 mL of a solution of FmocNCS (0.2M) in CH 2 Cl 2 was prepared. The reaction solution was added to 50 Lanterns from step (iii) and the Lanterns stood at room temperature for 6.5 h, then heated to 40° C. for the final 0.5 h (total of 7 h reaction time). At the conclusion of the reaction, the FmocNCS solution was drained and the Lanterns washed with CH 2 Cl 2 (4×10 min), DMF (2×10 min). These Lanterns were taken immediately to step (v).
[0000] Synthetic Step (v)
[0235] The Lanterns were firstly treated with 20% piperidine/DMF (v/v) at room temperature (2 treatments of 40 min and 1 h 20 min respectively; there were no washes in between treatments). The second piperidine solution was drained and the Lanterns washed with DMF (4×10 min). The lanterns were further reacted immediately.
[0236] A solution of iodomethane (0.2M) in DMF was prepared and added to the Fmoc-deprotected Lanterns. The Lanterns were allowed to stand at room temperature for 40 min. The iodomethane solution was then removed and the Lanterns subjected to a second solution of iodomethane (0.2M) in DMF for 40 min; there were no washes in between treatments. After the 40 min was complete, the reaction solution was drained and the Lanterns washed with DMF (5×10 min) and DMSO (1×10 min). The Lanterns were taken immediately to step (vi).
[0000] Synthetic Step (vi)
[0237] Four Lanterns from step (v) were added to a solution of 2-methylbenzylamine (2.0M) in DMSO then placed in an oven set to 85° C. for 6 h. At the completion of the reaction, the amine solution was drained and the Lanterns washed with hot (85° C.) DMSO (2×10 min, 2×30 min), DMF (3×10 min) and CH 2 Cl 2 (3×20 min). The Lanterns were then air dried overnight.
[0000] Synthetic Step (vii)
[0238] Two Lanterns were then added to a solution of cyclohexylmethylamine (1.0M) in DMSO then placed in an oven set to 100° C. for 4 days. At the completion of the reaction, the amine solution was drained and the Lanterns washed with hot (85° C.) DMSO (2×10 min, 2×30 min), DMF (3×10 min) and CH 2 Cl 2 (3×20 min). The Lanterns were then air dried overnight.
[0000] Synthetic Step (viii)
[0239] The Lanterns were cleaved using a solution of 20% TFA/CH 2 Cl 2 (v/v). The Lanterns were stood at room temperature for 1 h. The solution was evaporated under reduced pressure to give an oil. The oil was dissolved in 90% MeCN/H 2 O. The required tertiary guanidine was identified by analytical LCMS (purity=32%).
EXAMPLE 9
Effect of Arginine Analogues on Arginine Transport Across the Cell Membrane
[0240] A consolidated chemical library of all the compounds synthesised in Examples 1 to 6 was evaluated for their effect on NOS activity and L-arginine transport at high concentration. A total of 280 compounds was assayed.
[0241] The activity of the inducible isoform of NOS was tested by evaluating the ability of the compounds to interfere with NO production in J774 cells which had been exposed to an inflammatory cytokine cocktail. In brief, J774 cells were exposed to an inflammatory cytokine cocktail containing bacterial lipopolysaccharide (1 μg/ml) and interferon gamma (10 U/ml) for 24 hours, in the presence or absence of the test compound at 100 μM. The concentration of nitrite in the culture media was determined as an index of the amount of nitric oxide generated during the incubation period (Simmons et al, 1996.) A large number of inhibitory compounds was identified in this assay.
[0242] In parallel with this assay, the capacity for these compounds to alter arginine entry into cells was assessed. Initial studies were conducted in HeLa cells. Arginine entry was determined by the rate of entry of radiolabelled L-arginine into the cells, using the method of Kaye et al., (2000). Of the total library, four compounds were identified which had inhibitory activity at a Ki of 100 μM. These compounds were as follows:
[0243] However, when full concentration-response curves were prepared, it was found that, in contrast to the initial finding, four molecules exerted a stimulatory effect on L-arginine transport at low concentration (10 −7 and 10 −8 M), as shown in FIG. 2 . To our knowledge these are the first data to demonstrate that a synthetic compound is able to stimulate arginine transport. In the light of the foregoing discussion, we propose that this effect may be associated with therapeutic benefit.
[0244] Further studies have been performed to characterize the effects of compounds from library M0006 on arginine transport in endothelial cells. Studies performed in the endothelial cell line EA.hy.926 (Harrison-Shostak et al, 1997) have identified a number of compounds which exert a stimulatory effect on L-arginine transport. This cell line is considered to be more physiologically relevant than HeLa cells to the target conditions, and in fact was more sensitive. The results are summarised in FIG. 4 . Table 16 summarises results for the compounds so far identified which have the highest activity in the arginine transport assay.
TABLE 16 Summary of active structures (arginine uptake, at two concentrations 10 −8 M (top) and 10 −7 M (bottom)) Arg Plate uptake position Structure Structure Name (% control) Plate 1 A4 3-Cyclobutylmethoxy-4-[N′-(3,5- trifluoromethyl-benzyl)- guanidino]-benzamide 103% 108% Plate 1 A7 3-Cyclobutylmethoxy-4-[N′-(3,4- dichloro-benzyl)-guanidino]- benzamide 87% 66% Plate 1 A11 3-Cyclobutylmethoxy-4-[N′-(2- fluoro- benzyl)-guanidino]-benzamide 159% 128% Plate 1 A12 3-Cyclobutylmethoxy-4-[N′-(4- methyl- benzyl)-guanidino]-benzamide 179% 160% Plate 1 B4 3-Cyclobutylmethoxy-4-[N′-(2- methoxy- benzyl)-guanidino]-benzamide 130% 122% Plate 1 B12 3-Cyclobutylmethoxy-4-(N′- cyclohexyl-guanidino)-benzamide 161% 134% Plate 1 C12 3-Cyclopropylmethoxy-4-[N′-(2- phenyl-propyl)-guanidino]-benzamide 116% 133% Plate 1 F5 4-[N′-(2-Phenyl-propyl)- guanidino)- 3-(tetrahydro-pyran-2- ylmethoxy)-benzamide 135% 130% Plate 1 F9 4-(N′-Benzyl-guanidino)-3- (tetrahydro- pyran-2-ylmethoxy)-benzamide 140% 110% Plate 1 F10 4-(N′-Benzo[1,3]dioxol-5- ylmethyl- guanidino)-3-(tetrahydro-pyran- 2-ylmethoxy)-benzamide 119% 131% Plate 1 F12 4-(N′-Isobutyl-guanidino)-3- (tetrahydro- pyran-2-ylmethoxy)- benzamide 103% 146% Plate 1 G10 3-Cyclohexylmethoxy-4-[N′-(3,5- trifluoromethyl- benzyl)-guanidino]- benzamide 125% 188% Plate 1 H4 3-Cyclohexylmethoxy-4-[N′-(3,4- dichloro-benzyl)-guanidino]- benzamide 99% 92% Plate 1 H10 3-Cyclohexylmethoxy-4-[N′-(2- methoxy- benzyl)-guanidino]-benzamide 153% 146% Plate 1 H11 4-(N′-Benzyl-guanidino)-3- cyclohexylmethoxy-benzamide 131% 190% Plate 2 A10 3-Cyclohexylmethoxy-4-(N′- cyclohexylmethyl-guanidino)-benzamide 123% 127% Plate 2 D6 3-Benzyloxy-4-{N′-[(5-nitro- pyridin- 2-ylamino)-methyl]-guanidino}- benzamide 176% 138% Plate 2 E6 4-(N′-Benzyl-guanidino)-3- benzyloxy- benzamide 167% 160% Plate 2 F6 3-Benzyloxy-4-(N′-furan-2- ylmethyl- guanidino)-benzamide 158% 126% Plate 2 H8 4-(N′-Furan-2-ylmethyl- guanidino)-3- (3-methyl-benzyloxy)-benzamide 108% 182%
EXAMPLE 10
Effect of L-arginine Analogues on Vascular Tone
[0245] Initially four compounds were tested for their effect on vascular tone, using an isolated aortic ring assay. In this assay, sections of rat aorta are mounted in an organ bath, and tension is determined continuously using a strain gauge, as described by Furchgott & Zawadski (1980). The effect of test compounds on the vasorelaxant effect of the endothelial-dependent vasodilator acetyl choline was examined. Compounds A4 and H4, each at a concentration of 10 −8 M, were found to induce a significant augmentation of acetyl choline-induced vascular relaxation. These results are summarised in FIG. 4 . It will be appreciated that similar experiments may be performed using sections of human aorta, coronary artery or peripheral artery obtained at surgery.
EXAMPLE 11
Additional Characterization of L-arginine Analogues
[0246] Additional characterization of the compounds is also performed in primary cultures of isolated bovine aortic endothelial cells using the methods described in Example 9. Aortic endothelial cells are isolated from bovine aorta using standard cell culture methods (see for example Cocks et al, 1985). Similar methods may also be used to isolate human aortic, coronary artery or peripheral artery endothelial cells from surgical material so that the compounds can be tested in a human system.
EXAMPLE 12
Effect of L-arginine Analogues on Arginase Activity
[0247] The observed facilitatory action of the arginine analogues may possibly be explained by an inhibitory action upon the enzyme arginase. Such an effect would be expected to augment L-arginine transport and thereby to increase nitric oxide synthesis, in the absence of any inhibitory action upon nitric oxide synthase itself. The effect of the compounds on arginase enzymatic activity is determined by measuring the rate of production of urea by arginase in the presence of its substrate, L-arginine, and the compound of interest. These assays are performed in EA.hy.926 cells or in primary cultures of endothelial cells, obtained as described in Example 9. Alternatively they may be performed using aortic or other arterial rings, obtained as described in Example 10.
EXAMPLE 13
In Vivo Effects of L-arginine Analogues
[0248] Compounds found to be active in the in vitro studies are tested for their effects in vivo in experimental animals, and ultimately in humans.
[0249] In animal studies, the effect of the compound on blood pressure is tested following intravenous infusion into rats and rabbits. The effect of the compounds on regional vascular tone is tested by intra-arterial hindlimb infusions in rabbits, according to the method of Kaye et al., (1994). The effect of the compounds on coronary vascular resistance is tested by direct intracoronary infusion into sheep, using the method of Quyyumi et al., (1997).
[0250] Other suitable methods for in vivo assessment of efficacy, bioavailability and safety of the compounds of the invention will be known to those skilled in the art.
[0251] Once the pharmacological action of the compounds of the invention is established in animal studies, and their safety is assessed, further investigations are carried out on humans in vivo. For example, the effect of the compounds on forearm vascular tone is assessed by direct intra-arterial infusion, using the method of Kaye et al., (2000), and the effect of the compounds on blood pressure is evaluated.
[0252] It will be apparent to the person skilled in the art that while the invention has been described in some detail for the purposes of clarity and understanding, various modifications and alterations to the embodiments and methods described herein may be made without departing from the scope of the inventive concept disclosed in this specification.
[0253] References cited herein are listed on the following pages, and are incorporated herein by this reference.
REFERENCES
[0000]
Carey, F. A. and R. J. Sundberg. 1983. Advanced Organic Chemistry Part A: Structure and Mechanisms. New York, Plenum.
Carey, F. A. and R. J. Sundberg. 1983. Advanced Organic Chemistry Part B: Reactions and Synthesis. New York, Plenum.
Cocks T M, Angus J A, Campbell J H, and Campbell G R. Release and properties of endothelium-derived relaxing factor (EDRF) from endothelial cells in culture J Cell Physiol 1985;123:310-320.
Creager M A, Gallagher S J, Girerd X J, Coleman S M, Dzau V J, Cooke J P. L-arginine improves endothelium-dependent vasodilation in hypercholesterolemic humans. J Clin Invest. 1992;90:1248-1253.
Ellman, J. A., Thompson, L. A., Chem. Rev., 1996, 96, 555-600.
Furchgott R F, Zawadski J V. The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature. 1980;288:373-376.
Girerd X J, Hirsch A T, Cooke J P, Dzau V J, Creager M A. L-arginine augments endothelium-dependent vasodilation in cholesterol-fed rabbits. Circ Res. 1990;67:1301-1308.
Greene, T. W. and P. G. M. Wuts. 1991. Protective Groups in Organic Synthesis . New York, John Wiley & Sons, Inc.
Harrison-Shostak D. C. Lemasters, J. J. Edgell C. J. and Herman B. Role of ICE-like proteases in endotheleial cell hypoxic and reperfusion injury. Biochem. Biophys. Res. Comm. 1997:24:844-847
Hirooka Y, Imaizumi T, Tagawa T, Shiramoto M, Endo T, Ando S-I, Takeshita A. Effects of L-arginine on impaired acetylcholine-induced and ishemic vasodilation of the forearm in patients with heart failure. Circulation. 1994;90:658-668.
Kaye D M, Jennings G, Angus J A. Evidence for impaired endothelium dependent vasodilation in experimental left ventricular dysfunction. Clin Exp Pharmacol and Physiol. 1994;21:709-719.
Kaye D M, Ahlers B A, Autelitano D J et al. In vivo and in vitro evidence for impaired arginine transport in human heart failure. Circulation 2000, 102:2707-12.
Kearney, P. C., Fernandez, M., and Flygare, J. A., Tetrahedron Lett., 1998 39, 2663.
Lerman A, Burnett J C, Jr., Higano S T, McKinley L J, Holmes D R, Jr. Long-term L-arginine supplementation improves small-vessel coronary endothelial function in humans. Circulation. 1998;97:2123-2128.
Maeji, N. J., Valerio, R. M., Bray, A. M., Campbell, R. A. and Geysen, H. M. Grafted supports used with the multipin method of peptide synthesis. Reactive Polymers 1994, 22; 203.
March, J. 1992. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. New York, Wiley Interscience.
Macor J E and Kowala M C, Discovery Chemistry and Metabolic and Cardiovascular Drug Discovery Pharmaceutical Research Institute, Annual Reports in Medicinal Chemistry, 2000 35:63-70.
Maeji, N. J., Valerio, R. M., Bray, A. M., Campbell, R. A., Geysen, H. M., Reactive Polymers 1994, 22, 203-212.
Quyyumi A A, Dakak N, Diodati J G, et al. Effect of L-arginine on human coronary endothelium-dependent and physiologic vasodilation. J Am Coll Cardiol. 1997;30:1220-7.
Rector T S, Bank A J, Mullen K A, Tschumperlin L K, Sih R, Pillai K, Kubo S H. Randomized, double-blind, placebo-controlled study of supplemental oral L-arginine in patients with heart failure. Circulation. 1996;93:2135-2141.
Sirmnons W W, Closs E I, Cunningham J M et al J. Biol. Chem. 1996;271:11694-11702
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In the present specification we describe a new class of compounds, designed to modulate the ability of blood vessels to synthesize NO from L-arginine. In particular we have identified novel compounds which enhance the entry of L-arginine into cells. These compounds improve endothelial function, and thereby have the potential to retard the progression of vascular disease in conditions such as hypertension, heart failure and diabetes. This new class of drugs may also have other potentially, relevant pharmacological actions, including anti-hypertensive and anti-anginal actions.
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BACKGROUND OF THE INVENTION
This invention relates to graft polymerization of water-soluble monomers and starch. More specifically, it relates to graft polymerization under conditions such that the reaction mixture appears dry.
Water-soluble polymers, such as those containing polyacrylamide, are useful as flocculants for removal of suspended solids from water and as additives in the manufacture of paper. If we consider polyacrylamide as a representative example, prior art methods of preparation utilize the following techniques [N. M. Bikales, Polymer Sci. Technol. 2: 213 (1973)]:
1. The polymerization is carried out in water solution using any of the common initiators known in the prior art, e.g., sodium bromate-sodium sulfite.
2. The polymerization is run in an aqueous solution which is dispersed in the form of small droplets in an organic medium such as toluene.
3. The polymerization is carried out in a reaction medium in which acrylamide monomer is soluble but the polymer is not. An example of such a medium is a 40-55 percent solution of t-butyl alcohol in water, preferably in the presence of a salt.
All of these methods require an isolation and drying step. This step is often the most difficult and expensive step in the preparation of polyacrylamide and other water-soluble polymers. Polymers prepared in water solution are particularly difficult to isolate due to the high viscosities which develop as the reaction progresses.
The grafting of polyacrylamide and other water-soluble polymers onto starch is well known in the prior art, and the resulting graft copolymers find use in the same applications as the respective starch-free homopolymers. Similar to homopolymers, starch graft copolymers prepared by prior art methods all require an isolation and drying step.
Irradiation with cobalt-60 is also a commonly used method of initiating graft polymerization onto starch. Two general methods are used for cobalt-60 initiated graft polymerization: the simultaneous irradiation technique and the preirradiation technique. In the simultaneous technique, starch, in either a water solution, water dispersion, or water slurry, is mixed with a water solution of monomer and the resulting slurry, dispersion, or solution is then irradiated. In the preirradiation technique, starch is irradiated in the dry state but in the complete absence of monomer. The irradiated starch, which contains long-lived free radicals, is then added to a water solution of monomer to initiate polymerization. In both techniques, the final reaction product is a slurry, dispersion, or solution in water which is often viscous and difficult to handle. These solutions must then be dewatered and the graft copolymer isolated and dried using procedures which are time consuming and expensive.
The preparation of conventional starch derivatives using techniques where the amount of water in the reaction mixture is minimized to give an outwardly dry blend is well known in the prior art. However, in these conventional starch derivatives, the substituents which are reacted with and added to the starch backbone are of low molecular weight, e.g., acetyl, benzoyl, carboxymethyl, or aminoalkyl. Consequently, the product of the reaction is a highly substituted starch containing many substituents of low molecular weight (often one or more substituents per AGU).
Starch graft copolymers are vastly different in chemical structure from conventional starch derivatives. In a starch graft copolymer, a water solution of monomer is polymerized to give substituents which are of high molecular weight (usually more than 100,000) and which are very infrequently spaced long the starch backbone (usually more than 500 AGU separating each polymeric substituent). A technique using an outwardly dry blend of starch, monomer, and water, which is similar to that used to prepare a conventional starch derivative would not be expected to give useful products if it were used to prepare a starch graft copolymer. Since the amount of water in the system would necessarily be minimized, to give the required outwardly dry blend, the concentration of polymerizable monomer in the water solution which is blended with starch would be high. Concentrated solutions of monomer in water are known to polymerize extremely rapidly with the evolution of much heat. Such polymerizations are commonly known as "runaway" polymerizations and generally give polymers which would be crosslinked and therefore show a reduced solubility in water and would thus be of limited utility.
For a thorough discussion on starch graft polymerizations see "Block and Graft Copolymerization," Vol. 1, ed. R. J. Ceresa, John Wiley and Sons, New York, 1973, Chapters 1 and 2.
DETAILED DESCRIPTION OF THE INVENTION
We have discovered a novel method of polymerizing acrylamide and other water-soluble monomers such as N,N,N-trimethylaminoethyl methacrylate methyl sulfate, methacrylamide, acrylic acid, 2-hydroxy-3-methacryloyloxypropyltrimethyl ammonium chloride, and other water-soluble monomers known in the prior art.
In this method, polymerization is carried out onto and within an outwardly dry starch matrix using the following sequence of steps:
a. Preparing a concentrated aqueous solution containing from about 20 to 50 percent of a water-soluble monomer.
b. Adding starch to the solution resulting from step (a) in sufficient quantity to absorb all of the monomer solution and to give a reaction mass having an outwardly dry or slightly damp appearance. The added starch was present in quantities such that the ratio of starch to monomer on a dry weight basis was from 1:1 to 20:1 which resulted in a monomer add-on of 6 to 17 percent.
c. Purging the starch-monomer mixture resulting from step (b) with nitrogen. And
d. Irradiating the purged mixture resulting from step (c) with gamma rays from cobalt-60 to a total dose of about 0.1 Mrad.
Since the reaction mass is in an outwardly dry, free-flowing form from start to finish and conversions are near quantitative, no further treatment is needed; and the product is ready for use immediately. The low radiation doses needed for quantitative conversion of monomer to polymer (ca. 0.1 Mrad) make this method ideally suited for a continuous process. The reaction product is mainly starch graft copolymer, although about 5-15 percent of the monomer is converted to ungrafted homopolymer.
Any polysaccharide may be used as the matrix for the polymerization. Starch is the matrix of choice for the following reasons:
1. It is low in cost.
2. It is water dispersible and thus will give a final product which is also dispersible in water. High dispersibility and solubility are of key importance if the product is to function as a flocculant or a retention aid.
3. It may be readily depolymerized (for example, by treatment with enzymes) without altering synthetic polymer segments which might be grafted to it. Polymers containing low amounts of starch may therefore be easily prepared by simple procedures.
4. Commercially available starches come in grades which vary greatly in water solubility. Final products having a degree of water solubility varying from cold-water-soluble to hot-water-dispersible are thus easily prepared by choosing the proper grade of starch for the polymerization matrix.
Although our polymerization method uses high concentrations of monomer in water, we were surprised to find that the molecular weight of synthetic polymer was relatively low. Thus, in addition to serving as the matrix for the outwardly dry polymerization reaction and as a site for grafting, granular starch also moderates the polymerization. This was less true for pasted starch, since much higher molecular weights were obtained. High molecular weight polymer is the expected reaction product at the concentrations used in our polymerizations, and the literature even reports the formation of polyacrylamide having a molecular weight so high as to render it water insoluble, when high-monomer concentrations were used with cobalt-60 initiation (A. Chapiro, "Radiation Chemistry of Polymeric Systems," Interscience Publishers, 1962, page 328).
Since it is known in the prior art that high molecular weight water-soluble polymers are better flocculating agents than those of lower molecular weight, the lower molecular weight synthetic polymers produced by our method might seem to constitute a disadvantage. This, however, is not the case. Starch is a high molecular weight polysaccharide and therefore yields a graft copolymer whose overall molecular size is sufficiently large to permit it to function as a flocculant.
The following examples are intended only to further illustrate the invention and are not to be construed as limiting the scope of the invention which is defined by the claims. All percentages and ratios disclosed herein are by weight unless otherwise specified.
EXAMPLE 1
A solution of 1.42 g. (0.005 mole) of N,N,N-trimethylaminoethyl methacrylate methyl sulfate and 6.75 g. (0.095 mole) of acrylamide in 10 ml. of water was prepared to give a total monomer concentration in water of 45% by weight. This solution was then added to 47.0 g. of unmodified wheat starch containing 14% water (40.6 g. of starch, dry basis), and the mixture was thoroughly blended with a spatula. Although the starch now contained 28.8% water, by weight, it was still a free-flowing powder. The mixture was evacuated to 50 mm. and repressured with nitrogen (this procedure was repeated four times). The mixture was then irradiated with gamma rays from cobalt-60 (dose rate of 1.15 Mrad/hour) to a total dose of 0.1 Mrad and was then allowed to stand at ambient temperature for 2 hours. The reaction mass was an outwardly dry powder which could be used immediately without any further treatment.
Ungrafted homopolymer was removed from the product by cold water extraction and the extracted product dried to yield 48.2 g. of graft copolymer containing 16 percent grafted synthetic polymer conversion of monomers to grafted polymer was 93 percent. Conversion to homopolymer was 7 percent. The graft copolymer was treated with enzyme to remove starch and the remaining synthetic polymer analyzed. The intrinsic viscosity in 1N sodium nitrate at 30° C. was 1.4 dl./g.; and M n was 157,000 as determined by membrane osmometry.
EXAMPLE 2
A solution of 2.83 g. (0.01 mole) of N,N,N-trimethylaminoethyl methacrylate methyl sulfate and 13.5 g. (0.19 mole) of acrylamide in 20 ml. of water was prepared to give a total monomer concentration in water of 45 percent, by weight. To this solution was added 18.8 g. of unmodified wheat starch containing 13.7 percent water (16.2 g. of starch, dry basis). The mixture was stirred and heated to 64° C. to swell the starch granules and the resulting thick paste was allowed to stand at room temperature for 30 minutes. The mixture was then irradiated as in Example 1 to a total dose of 0.1 Mrad and allowed to stand at ambient temperature for 2 hours to yield a tough rubbery solid.
Ungrafted homopolymer was removed from the product by cold water extraction and the extracted product dried to yield 28.5 g. of graft copolymer containing 43 percent grafted synthetic polymer. Conversion of monomers to grafted polymer was 75 percent. Conversion to homopolymer was 15 percent. The graft copolymer was treated with enzyme to remove starch and the remaining synthetic polymer analyzed. The intrinsic viscosity in 1N sodium nitrate at 30° C. was 4.3 dl./g.
EXAMPLE 3
Example 1 was repeated with a commercially available starch which had been reduced in molecular weight to improve solubility (Stadex 60 dextrin). There was a minor difference in procedure from Example 1 in that N,N,N-trimethylaminoethyl methacrylate methyl sulfate was allowed to react for 1 hour in a 40 percent water solution with 0.052 ml. of dimethyl sulfate, to ensure that the monomer would be comletely in the quaternary ammonium form before polymerization. The conversion of monomers to polymer was quantitative, and the reaction mass was an outwardly dry powder which could be used immediately without any further treatment. The synthetic polymer content of the product was 17 percent.
EXAMPLE 4
A solution of 1.42 g. (0.005 mole) of N,N,N-trimethylaminoethyl methacrylate methyl sulfate and 6.75 g. (0.095 mole) of acrylamide in 18 ml. of water was prepared to give a total monomer concentration in water of 31.2 percent. N,N,N-Trimethylaminoethyl methacrylate methyl sulfate was allowed to react for 1 hour in a 40 percent water solution with 0.052 ml. of dimethyl sulfate, to ensure that the monomer would be completely in the quaternary ammonium form before polymerization. The solution of monomers in water was then added to 82.8 g. of a commercial modified corn starch of approximately 90 fluidity (Clinton 290B). The water content of the starch was 11.65 percent; the dry weight of starch was thus 73.2 g. The outwardly dry sample was irradiated under a nitrogen atmosphere as in Example 1 and allowed to stand at ambient temperature for 2 hours. The conversion of monomers to polymer was quantitative, and the reaction mass was an outwardly dry powder which could be used immediately without any further treatment. The synthetic polymer content of the product was 10 percent.
EXAMPLE 5
A solution of 7.1 g. of acrylamide (0.1 mole) in 10 ml. of water was prepared to give a monomer concentration in water of 41.5 percent. This solution was then added to 45.5 g. of Stadex 60 dextrin containing 10.8 percent water (40.6 g. of starch, dry basis), and the mixture thoroughly blended with a spatula. The free-flowing powder was irradiated with cobalt-60 under a nitrogen atmosphere, as in Example 1 to a total dose of 1 Mrad using a dose rate of 0.84 Mrad/hour. The conversion of monomer to polymer was quantitative, and the reaction mass was an outwardly dry powder which could be used without any further treatment. The graft copolymer was treated with enzyme to remove starch and the remaining synthetic polymer analyzed. The intrinsic viscosity in 1N sodium nitrate at 30° C. was 2.69 dl./g., corresponding to a calculated weight average molecular weight of 700,000.
EXAMPLE 6
A solution of 7.1 g. (0.1 mole) of acrylamide in 40 ml. of water was prepared to give a monomer concentration in water of 15.1 percent. This solution was then mixed with 8.9 g. of Stadex 60 containing 9.24 percent water (8.1 g. of starch, dry basis) and the mixture stirred and heated to 68° C. The resulting paste was cooled in ice for 30 minutes, irradiated with cobalt-60 (dose rate of 1.06 Mrad/hour) to a total dose of 0.1 Mrad, and allowed to stand at ambient temperature for 2 hours. The reaction mass was a thick paste. Conversion of monomer to polymer was 86 percent. The intrinsic viscosity of the polyacrylamide, after removal of starch with enzyme, was 3.8 dl./g. at 30° C. in 1N sodium nitrate. The calculated molecular weight was 1.18 × 10 6 .
EXAMPLE 7
A solution of 14.2 g. (0.2 mole) of acrylamide in 20 ml. of water was prepared to give a monomer concentration of 41.5 percent, by weight. This solution was then mixed with 17.8 g. of Stadex 60 containing 9.24 percent water (16.2 g. of starch, dry basis). The mixture was heated to 68° C. on a steam bath, cooled in an ice bath for 30 minutes, irradiated as in Example 6, and allowed to stand at ambient temperature for 2 hours. The reaction mass was a tough, rubbery solid. Conversion of monomer to polymer was 97 percent. The intrinsic viscosity of the polyacrylamide, after removal of starch with enzyme was 5.7 dl./g. at 30° C. in 1N sodium nitrate. The calculated molecular weight was 2.18 × 10 6 .
EXAMPLE 8
A solution of 14.2 g. (0.2 mole) of acrylamide in 20 ml. of water was prepared to give a monomer concentration in water of 41.5 percent, by weight. This solution was then treated in a manner identical to Example 7, but in the absence of starch. That is, the solution was heated to 68° C., cooled in an ice bath for 30 minutes, irradiated as in Example 6, and allowed to stand at ambient temperature for 2 hours. The reaction mass was a tough, rubbery solid; and the conversion of monomer to polymer was quantitative. The polymer was dewatered by treating the reaction mass with acetone and air drying to a water content of 15 percent. Polyacrylamide prepared by this technique in the absence of starch was only 18 percent soluble, as determined by stirring 0.5 g. of polymer in 375 ml. of water for 30 minutes in a boiling water bath, and would thus be totally useless as a flocculant or as a retention aid.
EXAMPLE 9
A partially neutralized acrylic acid solution of pH 4.8 was prepared by adding 9.5 ml. of 5M sodium hydroxide to 7.2 g. of glacial acrylic acid to give a monomer solution containing 46.6 percent solids by weight. This solution was then thoroughly blended with 46.4 g. (40.5 g., dry basis) of a commercially available acid-modified corn starch of approximately 40 fluidity (Clinton 240B). The water content of the starch was 12.8 percent. The resulting free-flowing powder was irradiated under nitrogen with cobalt-60 (dose rate of 0.88 Mrad/hour) to a total dose of 0.1 Mrad and was then allowed to stand at ambient temperature for 2 hours. The reaction product was an outwardly dry powder which could be used immediately without any further treatment. The conversion of monomer to polymer was quantitative, and the synthetic polymer content of the product was 17 percent.
EXAMPLE 9A
A partially neutralized acrylic acid solution of pH 4.8 was prepared by adding 3.5 ml. of 5M sodium hydroxide to 2.1 g. of glacial acrylic acid and then adding 6.5 ml. of water. The resulting monomer solution contained 19.3 percent solids, by weight. This solution was thoroughly blended with 44.8 g. (40.5 g., dry basis) of Stadex 60 having a water content of 9.6 percent. The resulting free-flowing powder was irradiated under nitrogen with cobalt-60 (dose rate of 0.92 Mrad/hour) to a total dose of 0.1 Mrad and was then allowed to stand at ambient temperature for 2 hours. The reaction product was an outwardly dry powder which could be used immediately without any further treatment. Conversion to polymer was quantitative, and the synthetic polymer content of the product was 6 percent.
EXAMPLE 10
A solution of 0.361 g. (0.005 mole) of glacial acrylic acid and 6.754 g. (0.095 mole) of acrylamide in 10 ml. of water was prepared to give a total monomer concentration in water of 41.5 percent. This solution was thoroughly blended with 45.7 g. (40.5 g., dry basis) of unmodified corn starch containing 11.5 percent water. The resulting free-flowing powder was irradiated under nitrogen (as in Example 1) with cobalt-60 (dose rate of 0.89 Mrad/hour) to a total dose of 0.1 Mrad and was then allowed to stand at ambient temperature for 2 hours. The reaction product was an outwardly dry powder which could be used immediately without any further treatment.
Ungrafted homopolymer was removed from the product by cold water extraction and the extracted product dried to yield 46.4 g. of graft copolymer. Conversion of monomers to grafted polymer was 83 percent. Conversion to homopolymer was 13 percent. The molecular weight of grafted synthetic polymer, after removal of starch by enzyme treatment, was 168,000, as determined by membrane osmometry.
EXAMPLE 11
A solution of 4.324 g. (0.06 mole) of glacial acrylic acid and 2.843 g. (0.04 mole) of acrylamide in 10 ml. of water was prepared to give a total monomer concentration in water of 41.7 percent. This solution was blended with unmodified corn starch and polymerized with cobalt-60 in the same manner as Example 10 to give a product similar in appearance.
Ungrafted homopolymer was removed by cold water extraction and the extracted product dried to yield 47.2 g. of graft copolymer. Conversion of monomers to grafted polymer was 92 percent.
Conversion to homopolymer was 8 percent. The molecular weight of grafted synthetic polymer, after removal of starch by enzyme treatment, ws 157,000, as determined by membrane osmometry.
EXAMPLE 12
A solution of 3.60 g. (0.05 mole) of glacial acrylic acid and 3.55 g. (0.05 mole) of acrylamide in 10 ml. of water was prepared. This solution was thoroughly blended with 43.6 g. (40.5 g., dry basis) of Stadex 60 dextrin. The resulting freeflowing powder was irradiated under nitrogen (as in Example 1) with cobalt-60 (dose rate of 1.13 Mrad/hour) to a total dose of 0.1 Mrad and was then allowed to stand at ambient temperature for 2 hours. Conversion of monomers to polymer was 92.3 percent, and the reaction product was an outwardly dry powder. The product contained 14 percent synthetic polymer.
EXAMPLE 13
In order to test the reaction product of Example 12 as a retention aid in the preparation of mineral-filled paper, a water solution was prepared by dispersing 0.486 g., dry basis, of the graft polymer in 375 ml. of water and then warming the dispersion to 60° C. The resulting clear solution was then diluted to a concentration of 200 mg. per liter.
Pulp furnish was a 50/50 blend of bleached softwood and bleached hardwood kraft containing 0.4 percent rosin, 2 percent alum, and 20 percent Huber HiWhite clay, based on the dry weight of pulp. Pulp furnish was prepared at a consistency of 2.5 percent and a pH of 5.6 and was diluted to 0.5 percent before use.
For laboratory retention tests, 600 ml. of pulp furnish (0.5 percent consistency) was placed in a 1-liter graduated cylinder and 25 ml. of polymer solution (200 mg./liter) added. The cylinder was inverted four times to assure good mixing and the contents filtered through a section of Fourdrinier wire. A 400-ml. portion of the filtrate was treated with 1 ml. of a 0.1 percent solution of Genfloc 155 to flocculate suspended solids, and the resulting mixture was filtered through tared Whatman 42 paper. The paper was dried and the weight of suspended solids determined. From the average of triplicate tests, suspended solids in the filtrate from the polymer-treated pulp furnish weighed 0.999 g., as compared with 0.235 g. for a control in which no polymer was added. This corresonds to a reduction in suspended solids of 58 percent from the control.
EXAMPLE 14
The reaction product of Example 12 was tested as a flocculant for silica (Celite) using a standard laboratory jar test apparatus. The graft polymer was dissolved by dispersing 0.5 g. of polymer in 375 ml. of water and heating the resulting dispersion to 90° C. in a boiling water bath. The resulting clear solution was diluted to a final concentration of 200 mg. per liter.
Polymer solution was added to a 3 percent suspension of Celite in tap water to give a final concentration of polymer of six parts per million and the resulting suspension stirred for 3 minutes at 100 r.p.m., 5 minutes at 50 r.p.m., and 1 hour at 20 r.p.m. After the mixture had settled for 15 minutes, the weight of suspended solids in 50 ml. of supernatant was 0.030 g., as compared with 1.25 for a control test in which no polymeric flocculant was added. Addition of polymer to a final concentration of 12 parts per million further reduced the suspended solids in 50 ml. of supernatant to 0.009 g.
EXAMPLE 14A
A solution of 3.55 g. of acrylamide and 3.60 g. of acrylic acid in 40 ml. of water was prepared and 8.7 g. (8.1 g., dry basis) of Stadex 60 was added. The mixture was stirred and heated on a steam bath to 68° C. and then cooled in ice water for 30 minutes. The mixture was irradiated with cobalt-60 (dose rate of 1.11 Mrad/hour) to a total dose of 0.1 Mrad and allowed to stand at ambient temperature for 2 hours. The thick, viscous paste was dewatered by blending with acetone and removing the solid by fitration. The solid polymer was then air dried to a water content of 10 percent. Conversion of monomers to polymer was 88 percent and the product contained 43.8 percent synthetic polymer, by weight.
EXAMPLE 14B
The product of Example 14A was tested as a retention aid using the method of Example 13, except that 15 ml. of the polymer solution (200 mg. per liter) was used in the test instead of 25 ml., due to the much larger amount of synthetic polymer in the product, as compared with the product of Example 12. Suspended solids in the filtrate from the polymer-treated pulp furnish weighed 0.098 g., as compared with 0.248 g. for a control in which no polymer was added. This corresponds to a reduction in suspended solids of 61 percent from the control.
EXAMPLE 15
The reaction product of Example 12 was tested as a flocculant for bentonite clay. A water solution of polymer, prepared as in Example 14, was added to 1 liter of a 0.5 percent suspension of bentonite clay in tap water in a graduated cylinder to give a final polymer concentration of 12 parts per million. The cylinder was inverted five times to assure thorough mixing and the suspension allowed to settle for 5 minutes. The percent transmission of the supernatant at 600 μ was 94 percent, as compared with 12 percent for a control in which no polymeric flocculant was added.
EXAMPLE 15A
The reaction product of Example 14A was tested as a flocculant for bentonite clay in the same manner as Example 15, except that the suspension was allowed to settle for 10 minutes instead of 5 minutes. The percent transmission of the supernatant was 93 percent at 600 mμ.
EXAMPLE 16
The product of Example 3 was dissolved in water and tested as a retention aid in the same manner as Example 13, except that 7.5 ml. of the polymer solution (200 mg. per liter) was used instead of 25 ml. Suspended solids in the filtrate from the polymer-treated pulp furnish weighed 0.100 g., as compared with 0.268 g. for a control in which no polymer was added. This corresponds to a reduction in suspended solids of 63 percent from the control.
EXAMPLE 17
The product of Example 3 was dispersed in water along with six times its weight of unmodified corn starch and was then used as a retention aid in the preparation of mineral-filled paper. A 32-inch Fourdrinier machine operating at 200 ft./minute was used, and the pulp furnish contained the same components as Example 13. Suspended solids in the white water were determined by filtering a known weight of white water through ashless Whatman 42 paper and then drying and weighing the paper. For determining filler retention, paper prepared on the Fourdrinier machine was ashed at 1098° K. for 1 hour.
The product of Example 3 functioned well as a retention aid, as shown by the following results.
______________________________________ Suspended Filler content ofAddition solids in manufacturedlevel, %.sup.a white water, % paper, %______________________________________0 (control) 0.090 6.70.075 0.071 12.60.15 0.052 13.00.225 0.041 12.80.3 0.034 12.9______________________________________ .sup.a Based on dry pulp furnish.
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A method was discovered of graft polymerizing water-soluble monomers with starch under conditions which are outwardly dry appearing. Conversion of monomer to polymer is nearly quantitative; and, since excess water is not present, there is no need for separate isolation and drying steps.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application 62/135,986, filed Mar. 20, 2015 by Gary Williams, et al., which is incorporated by reference as if set forth herein in its entirety.
BACKGROUND
[0002] 1. Field of the invention.
[0003] The invention relates generally to downhole tools for use in wells, and more particularly to means for controlling a downhole linear motor from the surface of a well in a manner that minimizes the connections that are necessary to communicate between the surface equipment and the downhole linear motor.
[0004] 2. Related art.
[0005] In the production of oil from wells, it is often necessary to use an artificial lift system to maintain the flow of oil. The artificial lift system commonly includes an electric submersible pump (ESP) that is positioned downhole in a producing region of the well. The ESP has a motor that receives electrical signals from equipment at the surface of the well. The received signals run the motor, which in turn drives a pump to lift the oil out of the well.
[0006] ESP motors commonly use rotary designs in which a rotor is coaxially positioned within a stator and rotates within the stator. The shaft of the rotor is coupled to a pump, and drives a shaft of the pump to turn impellers within the body of the pump. The impellers force the oil through the pump and out of the well. While rotary motors are typically used, it is also possible to use a linear motor. Instead of a rotor, the linear motor has a mover that moves in a linear, reciprocating motion. The mover drives a plunger-type pump to force oil out of the well.
[0007] In order to efficiently drive a linear motor, the position of the mover within the stator must be known. Linear motors typically use three Hall-effect sensors to determine the position of the mover. These three signals are provided to a control system, which then produces a drive signal based upon the position of the mover and provides this drive signal to the motor to run the motor.
[0008] If the linear motor is to be used in a well, however, there may be a number of problems with this arrangement. For example, because the motor is positioned in a well, it is necessary to communicate the mover position signals over a substantial length (thousands, or even tens of thousands of feet) of cabling to equipment at the surface of the well. It is therefore impractical simply to provide the wires for separate electrical lines to communicate the mover position signals from the linear motor to the surface equipment. Even if the mover position signals were serially combined and communicated over a single electrical line, the higher bandwidth signal, which must be transmitted adjacent to the power cable, which carries high motor switching currents and will therefore degrade the signal-to-noise ratio of the mover position signals.
[0009] It would therefore be desirable to provide improved means for communicating necessary information about the position of the mover in a downhole linear motor to equipment at the surface of a well, and for utilizing this position information to generate signals to drive the linear motor.
SUMMARY OF THE INVENTION
[0010] This disclosure is directed to systems and methods for controlling downhole linear motors in a manner that minimizes the connections necessary to communicate between surface equipment and the downhole linear motors. In one particular embodiment, a system includes an ESP system that is coupled by a power cable to equipment positioned at the surface of a well. The ESP system includes a linear motor and a reciprocating pump that is coupled to be driven by the motor. The motor has a set of position sensors that are configured to sense that a mover of the motor is in a corresponding position within the motor. The ESP system also includes circuitry (an XOR gate, for example) that combines the outputs of each of the position sensors into a single composite signal. The signal components corresponding to each of the position sensors, such as rising or falling edges, are indistinguishable. In other words, the position sensors are not identifiable from the components of the composite signal. A single channel is coupled between the ESP system and the surface equipment to carry the composite signal from the ESP system to the surface equipment. This channel may be implemented on a dedicated signal line, or as a virtual channel on the power cable.
[0011] In one embodiment, the surface equipment includes a control system such as a VSD that receives the composite signal and produces output power for the ESP system based at least in part on the composite signal. The VSD may include a speed controller that is configured to determine a current speed of the motor and to control the VSD to produce output power which drives the ESP system at a desired speed. The control system may be configured to perform an initialization procedure at startup and thereby identify a starting position of the mover in the linear motor (e.g., at the bottom of the motor, which may be the top of the power stroke). After initialization, the control system may produce an initial power stroke voltage and monitor the composite signal to determine whether the mover has moved. If the mover has moved in response to the initial power stroke voltage, the control system continues to provide the initial power stroke voltage to the ESP system. If the mover has not moved in response to the initial power stroke voltage, the control system increases the output voltage and continues monitoring the composite signal to determine whether the mover has moved in response to the increased voltage.
[0012] One alternative embodiment comprises a controller of the type that may be used in a VSD for an electric submersible pump (ESP) system. This controller is configured to receive a composite signal from an ESP system, where the composite signal includes signal components corresponding to a plurality of position sensors in the ESP system. The controller performs an initialization procedure in order to identify a starting position of a mover in the linear motor (which may involve moving mover to that position). The controller then produces output power based on the identified starting position of the mover in the linear motor and provides the output power to the linear motor of the ESP system. The control functions may be implemented, for example, in a variable speed drive (VSD) that includes a speed controller, where the speed controller is configured to receive the composite signal and to control the VSD to produce the output power at a frequency and a voltage that are determined based on the composite signal.
[0013] Another alternative embodiment comprises a method for controlling an ESP positioned downhole in a well, where the ESP has a linear motor and reciprocating pump, and where position sensors in the motor provide outputs that are combined into a composite signal that is conveyed to a control system at the surface of the well. The method includes receiving the composite signal in a drive controller, performing an initialization procedure to identify a starting position of a mover in the linear motor, and producing output power that drives the linear motor based on the identified starting position of the mover. In one embodiment, the initialization procedure involves producing an output voltage that is adapted to move the mover in a return stroke direction, monitoring the composite signal, and determining from the composite signal when the mover has moved to the end of the return stroke (the top of the power stroke). After determining that the mover has moved to the end of the return stroke, an output voltage is produced that is adapted to move the mover in a power stroke direction. This may include producing an initial power stroke voltage, monitoring the composite signal, and determining from the composite signal whether the mover has moved in response to the initial voltage. If the mover has moved in response to the initial voltage, the control system continues to produce this voltage. If the mover has not moved in response to the initial voltage, the voltage is increased and the composite signal continues to be monitored to determine whether the mover has moved in response to the increased voltage. As the mover moves through the power stroke, events in the composite signal corresponding to movement of the mover (e.g., signal transitions—rising or falling edges) are counted, and the count is compared to a predetermined maximum number. If the count has reached the predetermined maximum number, the power stroke is complete, and a return stroke voltage is produced. If the count has not reached the predetermined maximum number, the control system continues to produce the power stroke voltage. As the mover moves through the power stroke, the control system may compare a frequency of the linear motor to a power stroke profile and adjust the power stroke voltage based on the comparison.
[0014] Numerous other embodiments are also possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Other objects and advantages of the invention may become apparent upon reading the following detailed description and upon reference to the accompanying drawings.
[0016] FIG. 1 is a diagram illustrating an exemplary pump system in accordance with one embodiment.
[0017] FIG. 2 is a diagram illustrating an exemplary linear motor in accordance with one embodiment which would be suitable for use in the pump system of FIG. 1 .
[0018] FIG. 3 is a functional block diagram illustrating the structure of a control system for a linear motor in accordance with one embodiment.
[0019] FIG. 4 is a flow diagram illustrating a scheme through which the motor speed controller controls the inverter to generate the output waveform that drives the motor in accordance with one embodiment.
[0020] FIGS. 5A-5C are diagrams illustrating the control scheme of FIG. 4 in more detail.
[0021] While the invention is subject to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and the accompanying detailed description. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular embodiment which is described. This disclosure is instead intended to cover all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims. Further, the drawings may not be to scale, and may exaggerate one or more components in order to facilitate an understanding of the various features described herein.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0022] One or more embodiments of the invention are described below. It should be noted that these and any other embodiments described below are exemplary and are intended to be illustrative of the invention rather than limiting.
[0023] As described herein, various embodiments of the invention comprise systems and methods for communicating information between a downhole linear motor and controls for the motor which are located at the surface of a well, and operating the motor using the communicated information. The embodiments of the invention reduce the bandwidth and/or conductor count of the feedback signal from position sensors on the downhole motor to the drive at the surface of the well. Channels that are conventionally provided for this information have a very high cost, so reducing the channels reduces this cost. Additionally, the cost of downhole electronics is very high, so reducing the circuitry required in the motor results in additional cost savings, as well as extending the run life of the motor.
[0024] Referring to FIG. 1 , a diagram illustrating an exemplary pump system in accordance with one embodiment of the present invention is shown. A wellbore 130 is drilled into an oil-bearing geological structure and is cased. The casing within wellbore 130 is perforated in a producing region of the well to allow oil to flow from the formation into the well. Pump system 120 is positioned in the producing region of the well. Pump system 120 is coupled to production tubing 150 , through which the system pumps oil out of the well. A control system 110 is positioned at the surface of the well. Control system 110 is coupled to pump 120 by power cable 112 and a set of electrical data lines 113 that may carry various types of sensed data and control information between the downhole pump system and the surface control equipment. Power cable 112 and electrical lines 113 run down the wellbore along tubing string 150 .
[0025] Pump 120 includes an electric motor section 121 and a pump section 122 . In this embodiment, an expansion chamber 123 and a gauge package 124 are included in the system. (Pump system 120 may include various other components which will not be described in detail here because they are well known in the art and are not important to a discussion of the invention.) Motor section 121 receives power from control system 110 and drives pump section 122 , which pumps the oil through the production tubing and out of the well.
[0026] In this embodiment, motor section 121 is a linear electric motor. Control system 110 receives AC (alternating current) input power from an external source such as a generator (not shown in the figure), rectifies the AC input power and then converts the DC (direct current) power to produce three-phase AC output power which is suitable to drive the linear motor. The output power generated by control system 110 is dependent in part upon the position of the mover within the stator of the linear motor. Position sensors in the motor sense the position of the mover and communicate this information via electrical lines 113 to control system 110 so that the mover will be driven in the proper direction (as will be discussed in more detail below). The output power generated by control system 110 is provided to pump system 120 via power cable 112 .
[0027] Referring to FIG. 2 , a diagram illustrating an exemplary linear motor which would be suitable for use in the pump system of FIG. 1 is shown. The linear motor has a cylindrical stator 210 which has a bore in its center. A base 211 is connected to the lower end of stator 210 to enclose the lower end of the bore, and a head 212 is connected to the upper end of the stator. Motor head 212 has an aperture therethrough to allow the shaft of the mover to extend to the pump.
[0028] Stator 210 has a set of windings 213 of magnet wire. The ends of the windings are coupled (e.g., via a pothead connector 214 ) to the conductors of the power cable 218 . The windings are alternately energized to generate magnetic fields within the stator that interact with permanent magnets 221 on the shaft 222 of mover 220 . The waveform of the signal on the power cable (in this case a three-phase signal) is controlled to drive mover 220 in a reciprocating motion within the bore of stator 210 . Stator 210 incorporates a set of three Hall-effect sensors 215 to monitor the position of mover 220 within stator 210 . The outputs of Hall-effect sensors 215 are each coupled to corresponding inputs of an XOR gate 216 . The output of XOR gate 216 is connected to a single electrical line 230 . In an alternative embodiment, the output of XOR gate 216 could be processed by additional circuitry that impresses this signal onto power cable 218 and thereby communicates the signal to the equipment at the surface of the well.
[0029] Conventionally, each of the three signals output by the Hall-effect sensors would be transmitted to the controller. In other words, each of the three distinct outputs of the Hall-effect sensors would be maintained. Additionally, the mover would be coupled to an absolute position encoder of some type and this data would also be transmitted to the controller. The transmission of all of this information would require either a high bandwidth signal or a wide signal bus consisting of separate wires. Because of the constraints of communicating between the downhole motor and the surface equipment, neither of these options is available. The present systems and methods therefore encode the Hall-effect sensor information into a single, real-time composite signal which is communicated from the linear motor to the drive system at the surface of the well. The absolute position encoder signal is removed altogether. The drive system is configured to track the motor position based on this single signal.
[0030] A nominal 24 volts DC is supplied from the drive at the surface to the linear motor. This voltage is converted to a local power voltage with a linear voltage regulator. The local voltage powers the circuitry in the motor, which includes the Hall-effect sensors and a quad XOR gate. The three Hall-effect sensors sense the passage of the magnets of the mover within the stator and pass this information to the XOR gate. The XOR gate encodes this information into a single differential signal which is a composite of the separate signals output by the Hall-effect sensors. The resulting waveform is a square wave with each edge (rising and falling) denoting a change in the location of the mover. These edges correspond to transitions between the six motor voltage steps that are generated by the drive system. The differential signal generated by the XOR gate is transmitted from the linear motor back to the drive at the surface of the well. The channel through which the signal is transmitted may be a dedicated physical signal line, or it may be a virtual channel through which the signal is communicated over the power leads that couple the motor to the drive at the surface of the well.
[0031] Referring to FIG. 3 , a functional block diagram illustrating the structure of a control system for a linear motor in one embodiment is shown. The control system is incorporated into a drive system for the linear motor. The drive system receives AC input power from an external source and generates three-phase output power that is provided to the linear motor to run the motor. The drive system also receives position information from the linear motor and uses this information when generating the three-phase power for the motor.
[0032] As depicted in FIG. 3 , drive system 300 has input and boost circuitry 310 that receives AC input power from the external power source. The input power may be, for example, 480V, three-phase power. Circuitry 310 converts the received AC power to DC power at a predetermined voltage and provides this power to a first DC bus. The DC power on the first DC bus is provided to a variable DC-DC converter 320 that outputs DC power at a desired voltage to a second DC bus. The voltage of the DC power output by DC-DC converter 320 can be adjusted within a range from 0V to the voltage on the first DC bus, as determined by a voltage adjustment signal received from motor speed controller 340 . The DC power on the second DC bus is input to an inverter 330 which produces three-phase output power at a desired voltage and frequency. The output power produced by inverter 330 is transmitted to the downhole linear motor via a power cable.
[0033] The power output by inverter 330 is monitored by voltage monitor 350 . Voltage monitor 350 provides a signal indicating the voltage output by inverter 330 as an input to motor speed controller 340 . Motor speed controller 340 also receives position information from the downhole linear motor. In one embodiment, this position information consists of the output of the XOR gate as described above in connection with FIG. 2 . Motor speed controller 340 uses the received position information to determine the position of the mover within the linear motor and, based upon this position information and the information received from voltage monitor 350 , controls inverter 330 to generate the appropriate output signal. In one embodiment, motor speed controller 340 controls the switching of insulated gate bipolar transistors (IGBT's) in inverter 330 to generate the desired output waveform, which in this embodiment is a 6-step waveform.
[0034] The downhole linear motor is an electrically commutated motor. In other words, the commutation or changing of the voltage of the power provided to the motor is accomplished via the surface drive unit. The edges of the XOR'd signal from the Hall-effect sensors are indications of where the commutation should occur. This is explained in more detail in connection with FIGS. 4 and 5 .
[0035] FIGS. 4 and 5 are flow diagrams illustrating the scheme through which the motor speed controller controls the inverter to generate the output waveform that drives the motor. FIG. 4 depicts the three basic stages of this process, while FIG. 5 shows the process in more detail.
[0036] As noted above, the absolute position of the mover within the linear motor is not communicated to the drive—the outputs of the Hall-effect sensors are XOR'd, so the signal received by the motor speed controller indicates the points at which edges occur in all three of the sensor signals. The drive must therefore determine where the mover is positioned within the motor. In order to do this, the drive performs an initialization process ( 410 ) when the unit is powered up. In one embodiment, this consists of applying a voltage to the motor that is known to be sufficient to cause the mover to travel to the top of the power stroke. The return stroke direction is used for this purpose because the force required to move in this direction is less than the power stroke direction, and the required force is predictable, regardless of the depth of the well or other well-specific parameters. The initialization procedure can optionally be repeated in the power stroke direction to verify that the full stroke length is obtainable.
[0037] After the motor has been initialized, it can be assumed that the mover is at the top of the power stroke. The drive then produces the appropriate output voltages for the power stroke ( 420 ) and, as it does so, the drive monitors the XOR signal and interprets each edge as the edge of one of the Hall-effect sensor signals. Since the edges of these signals occur in a known order during the power stroke of the motor, the drive effectively knows which of the sensors generated each edge of the received signal. At the end of the power stroke, it is known that the mover is at the top of the return stroke, so the appropriate voltages are generated for the return stroke ( 430 ). As the mover moves through the return stroke, the drive continues to monitor the XOR signal and interprets each edge as the edge of one of the Hall-effect sensor signals, which occur in a known order during the return stroke.
[0038] The commutation of the motor (repeating power stroke 420 and return stroke 430 ) can be performed automatically. This will allow the motor to run smoothly, with transitions in the XOR'd Hall-effect sensor signal being reported to the drive. As noted above, counting the transitions in this signal allows tracking of the mover position. Additionally, the frequency of the transitions is used to determine the mover speed. The voltage on the second DC bus can be adjusted to make the mover go faster (by making the DC bus voltage higher) or slower (by making the DC bus voltage lower). The combination of the frequency of the transitions and the motor current that is supplied to the motor can also be used for well diagnostics (e.g., determining the presence of gas, stuck valves, etc.)
[0039] In one embodiment, an inhibit mode is included in the hardware (e.g., by setting an appropriate bit) so that the hardware commutation of the motor is disabled during the initialization process. The drive can then manually commutate the motor in the return direction and monitor the XOR'd Hall-effect sensor signals, which indicates that the mover is moving in response to each step change in the motor voltages. Initially, the motor may move backwards to get in sync—this is acceptable behavior and does not affect the outcome of the initialization routine. The mover will eventually come to rest against a hard stop located in the end of the motor. When this point is reached, the XOR'd Hall-effect sensor input signal will stop transitioning. After the initialization phase has been completed, the inhibit bit may be released, and commutation of the motor can be done automatically in hardware.
[0040] Referring to FIG. 5 , the drive starts the initialization phase of the process by causing the mover to travel through the return stroke to the top of the power stroke. Depending upon the initial position of the mover, it may not have to travel through the entire return stroke. The maximum voltage and current that should be necessary to move the mover in the return stroke direction (under essentially any well conditions) are known, so the drive output is set to this maximum voltage ( 511 ). The motor is stepped forward one position in the return stroke ( 512 ), and the XOR'd signal from the Hall-effect sensors is monitored for changes. If there are changes in the signal ( 513 ), the mover is advancing in the return stroke, so the drive output is controlled to advance the motor another step in the return stroke ( 512 ). These steps are continued until the stepping the motor results in no changes in the XOR'd Hall-effect sensor signal. This indicates that the mover has completed the return stroke. A stop in the motor prevents the mover from moving any farther in the return stroke direction. At this point, the mover is at the top of the power stroke ( 515 ), and the drive output should be at the halfway point of its electrical cycle ( 514 ).
[0041] After the initialization phase has been completed, the power stroke is initiated.
[0042] In this phase, an initial power stroke voltage is output to the motor ( 521 ). The XOR'd signal from the Hall-effect sensors is monitored for changes indicating movement of the mover ( 522 ). If there are no changes in the signal, it is assumed that the mover has not moved, so the voltage is increased ( 525 ), and the increased voltage is provided to the motor ( 521 ). If there are changes in the signal, the detected edges increment a counter, and the value of the counter is compared to a maximum value ( 523 ). If the maximum value has not been reached, the power stroke is not complete, so the output voltage is compared to a profile of the power stroke to determine whether the output voltage should be increased ( 525 ) or decreased ( 526 ). After the voltage is adjusted as needed, the new voltage is output to the motor ( 521 ). Returning to comparison 523 , if the counter has reached the maximum value, the power stroke is complete.
[0043] After completion of the power stroke, the return stroke is initiated. The steps performed by the drive during the return stroke are similar to those performed during the power stroke, except that they are adapted to move the motor's mover in the opposite direction. Since the pump is not lifting oil out of the well during the return stroke, the voltages required to be output by the drive will normally be less than the voltages output during the power stroke.
[0044] At the beginning of the return stroke, an initial return stroke voltage is output to the motor ( 531 ). The drive monitors the XOR'd Hall-effect sensor signal to detect changes which indicate movement of the mover ( 532 ) in the return direction. If there are no changes in the signal, indicating no movement of the mover, the voltage is increased ( 535 ). This increased voltage is provided to the motor ( 531 ). If, on the other hand, there are changes in the signal, the counter is incremented to count the signal's edges. The value of the counter is then compared to the maximum value ( 533 ) to determine whether the return stroke is complete. If the count is less than the maximum value, the output voltage is compared to a return stroke profile ( 534 ) to determine whether the output voltage should be increased ( 535 ) or decreased ( 536 ). The voltage is adjusted as indicated by the comparison to the return stroke profile, and the new voltage is output to the motor ( 531 ). If, when the counter value is compared to the maximum value, the count has reached the maximum value, the return stroke is complete, so the drive begins the next power stroke.
[0045] The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the claims. As used herein, the terms “comprises,” “comprising,” or any other variations thereof, are intended to be interpreted as non-exclusively including the elements or limitations which follow those terms. Accordingly, a system, method, or other embodiment that comprises a set of elements is not limited to only those elements, and may include other elements not expressly listed or inherent to the claimed embodiment.
[0046] While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention as detailed within the following claims.
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Systems and methods for controlling downhole linear motors to minimize connections to surface equipment. In one embodiment, an ESP system is coupled by a power cable to equipment at the surface of a well. The ESP system includes a linear motor and a reciprocating pump. The motor has a set of position sensors that sense the position of a mover in the motor. Combining circuitry (E.G., XOR gate) combines the outputs of the position sensors into a single composite signal in which signal components corresponding to the position sensors are indistinguishable. A single channel carries the composite signal from the ESP system to the surface equipment. A control system determines a starting position of the motor and determines its subsequent position based on transitions in the composite signal. The motor is then operated based on the position determined from the composite signal.
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TECHNICAL FIELD
[0001] A fuel tank assembly includes a fuel tank pivotally coupled to a frame by a hinge assembly.
BACKGROUND
[0002] Many conventional vehicles, such as saddle-type vehicles, include a fuel tank which is positioned upon the vehicle to attain optimal performance and styling, and when possible, configured for movement to facilitate accessibility to an underlying area beneath the fuel tank.
SUMMARY
[0003] In accordance with one embodiment, a fuel tank assembly comprises a hinge assembly, a fuel tank, and at least one hinge bolt. The hinge assembly comprises a hinge pin and a hinge stay. The hinge pin pivotally couples the hinge stay to a vehicular frame and defines a hinge axis about which the hinge stay is pivotable. The fuel tank includes a front end and a rear end. The at least one hinge bolt releasably couples the hinge stay to the fuel tank such that the fuel tank is pivotable about the hinge axis. The at least one hinge bolt intersects the hinge axis and obstructs the hinge pin from being removed from the hinge stay.
[0004] In accordance with another embodiment, a vehicle comprises a frame, a hinge assembly, a fuel tank, and at least one hinge bolt. The hinge assembly comprises a hinge pin and a hinge stay. The hinge pin pivotally couples the hinge stay to the frame and defines a hinge axis about which the hinge stay is pivotable with respect to the frame. The fuel tank includes a front end and a rear end. The at least one hinge bolt releasably couples the hinge stay to the fuel tank such that the fuel tank is pivotable with respect to the frame about the hinge axis. The at least one hinge bolt intersects the hinge axis and obstructs the hinge pin from being removed from the hinge stay.
[0005] In accordance with yet another embodiment, a saddle-type vehicle comprises a frame, at least two wheels, a hinge assembly, a fuel tank, a first hinge bolt, and a second hinge bolt. The at least two wheels are rotatably coupled to the frame. The hinge assembly comprises a hinge pin and a hinge stay. The hinge pin pivotally couples the hinge stay to the frame and includes a first end and a second end. The hinge pin defines a hinge axis about which the hinge stay is pivotable with respect to the frame. The fuel tank includes a front end and a rear end. The first and second hinge bolts releasably couple the hinge stay to the front end of the fuel tank such that the fuel tank is pivotable about the hinge axis. A substantially vertical imaginary plane extends between the front end and the rear end of the fuel tank and is substantially perpendicular to the hinge axis. The substantially vertical imaginary plane intersects the hinge stay to define left and right sides of the hinge stay. The first and second hinge bolts are disposed on opposite sides of the imaginary plane. The first hinge bolt intersects the hinge axis. The first end of the hinge pin is provided with at least one of a cotter pin and a circlip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] It is believed that certain embodiments will be better understood from the following description taken in conjunction with the accompanying drawings in which:
[0007] FIG. 1 is a front perspective view of a vehicle, according to one embodiment;
[0008] FIG. 2 is an enlarged front perspective view depicting a fuel tank assembly of the vehicle of FIG. 1 , wherein the fuel tank assembly includes a hinge assembly having first and second hinge bolts, a flange, a hinge stay, and a hinge pin;
[0009] FIG. 3 is an upper perspective view depicting the fuel tank assembly of FIG. 2 ;
[0010] FIG. 4 is a cross-sectional view taken along the line 4 - 4 in FIG. 3 and depicting the first hinge bolt intersecting a hinge axis defined by the hinge pin;
[0011] FIG. 5 is an enlarged front view depicting the fuel tank assembly of FIG. 2 with the hinge pin shown in solid lines in an installed position and shown in dashed lines in a partially removed position;
[0012] FIG. 6 is a front view depicting a fuel tank assembly according to another embodiment, wherein the fuel tank assembly includes a hinge assembly and a hinge pin, and the hinge pin is shown in solid lines in an installed position and is shown in dashed lines in a partially removed leftward position and a partially removed rightward position; and
[0013] FIG. 7 is a top perspective view depicting the fuel tank assembly of FIG. 6 .
DETAILED DESCRIPTION
[0014] Embodiments are hereinafter described in detail in connection with the views and examples of FIGS. 1-7 , wherein like numbers indicate the same or corresponding elements throughout the views. A vehicle, such as vehicle 10 depicted in FIG. 1 , can include a pivotable fuel tank pivotally mounted to a frame. The vehicle 10 is depicted in FIG. 1 to be an all-terrain vehicle (“ATV”). However, any of a variety of vehicles can be provided having a pivotable fuel tank mounted to a frame. For example, a vehicle can include any of a variety of saddle-type vehicles, such as a motorcycle, or any of a variety of non-saddle type vehicles, such as, for example, an automobile, a truck, a van, a scooter, a recreational vehicle, a watercraft, an aircraft, agricultural equipment, construction equipment, a toy, or a mower.
[0015] As illustrated in FIG. 1 , the vehicle 10 can include a frame 16 that supports an engine (not shown) and rotatably supports a plurality of wheels (e.g,. 19 ). As illustrated in FIG. 2 , a fuel tank assembly 12 can be supported upon the frame 16 . The fuel tank assembly 12 is shown to include a fuel tank 22 that is pivotally coupled to the frame 16 by a hinge assembly 14 . The hinge assembly 14 can include a hinge pin 18 and a hinge stay 20 . As illustrated in FIG. 2 , the hinge stay 20 can include an elongated central portion 23 and a pair of end portions 25 . Each of the end portions 25 can extend generally downwardly from the elongated central portion 23 such that the end portions 25 are substantially perpendicular to the elongated central portion 23 . Each of the end portions 25 can define a hinge stay aperture (e.g., 21 ) that is configured to receive the hinge pin 18 .
[0016] The frame 16 can include a head tube 44 having a pair of upright members 48 . The hinge pin 18 can pass through each of the upright members 48 and the end portions 25 to facilitate pivotal coupling of the hinge stay 20 with respect to the frame 16 . Each of the upright members 48 can define a frame aperture (e.g., 49 ) that is configured to accommodate receipt of the hinge pin 18 . The frame apertures (e.g., 49 ) can be substantially aligned with the hinge stay apertures (e.g., 21 ) to facilitate receipt of the hinge pin 18 . The hinge pin 18 can define a hinge axis A 1 and the hinge stay 20 can be pivotable with respect to the frame 16 about the hinge axis A 1 .
[0017] While FIG. 2 depicts the upright members 48 of the head tube 44 positioned between the end portions 25 of the hinge stay 20 , it will be appreciated that a hinge stay can be pivotally coupled to a frame in any of a variety of suitable alternative arrangements such as, for example, a hinge stay being positioned between upright portions of a head tube. It will also be appreciated that a hinge stay and frame can be provided in any of a variety of suitable alternative arrangements for pivotally supporting a fuel tank.
[0018] In addition to being coupled to the frame 16 , the hinge stay 20 can be coupled to the fuel tank 22 such that the fuel tank 22 is pivotable with respect to the frame 16 about the hinge axis A 1 . As illustrated in FIG. 2 , first and second hinge bolts 34 , 36 can facilitate releasable coupling of the hinge stay 20 to the fuel tank 22 . The first and second hinge bolts 34 , 36 can be threadedly engaged with respective nuts (e.g., 50 in FIGS. 4 and 5 ). In one embodiment, the nuts 50 can comprise weld nuts. It will be appreciated that a hinge stay can be secured to the fuel tank with any of a variety of fasteners and/or attachment arrangements.
[0019] The fuel tank 22 can include a front end 24 and a rear end 26 . In one embodiment, as illustrated in FIGS. 2-4 , the front end 24 of the fuel tank 22 can comprise a flange 28 which can be configured to receive the first and second hinge bolts 34 , 36 . In such an embodiment, the first and second hinge bolts 34 , 36 can extend through the flange 28 . While the fuel tank 22 in the embodiment of FIGS. 2-5 is shown to include the flange 28 , it will be appreciated that any of a variety of other suitable fuel tank configurations can be provided that accept receipt of a fastener or other fastening arrangements for securing the hinge stay 20 to the fuel tank 22 .
[0020] In the embodiment of FIGS. 2-3 , the hinge stay 20 can be coupled to the front end 24 of the fuel tank 22 such that an area beneath the fuel tank 22 can be accessed from the rear end 26 of the fuel tank 22 . As illustrated in FIG. 3 , a rear bolt 37 can releasably secure the rear end 26 of the fuel tank 22 to the frame 16 and thus prevent the fuel tank 22 from pivoting about the hinge axis A 1 . The rear bolt 37 can be selectively removed to permit the pivoting of the fuel tank 22 away from the frame 16 . It will be appreciated that the hinge assembly 14 can be arranged anywhere on the tank 22 so as to permit pivoting of the fuel tank 22 in a particular direction (e.g., leftwardly or rightwardly). It will also be appreciated that a fuel tank can be coupled to another portion of a frame or other portion of a vehicle by a hinge assembly. In particular, while FIG. 2 shows the frame apertures 49 to be defined by portions of the head tube 44 , it will be appreciated that one or more frame apertures can be positioned on other portions of a frame in any of a variety of other suitable configurations.
[0021] As illustrated in FIG. 2 , the head tube 44 can pivotally support a steering shaft 46 that is coupled to a pair of handlebars ( 27 in FIG. 1 ). The hinge stay 20 and the fuel tank 22 can define a gap through which the head tube 44 and the steering shaft 46 can pass. As illustrated in FIG. 3 , an imaginary plane P 1 can extend between the front end 24 and the rear end 26 of the fuel tank 22 . The imaginary plane P 1 can be a substantially vertical plane that is substantially perpendicular to the hinge axis A 1 . The imaginary plane P 1 can intersect (e.g., bisect) the hinge stay 20 to define left and right sides 30 , 32 of the hinge stay 20 . The first and second hinge bolts 34 , 36 can be disposed entirely on opposite sides of the hinge stay 20 . In some embodiments, the hinge stay 20 can be releasably secured to the fuel tank 22 with less than or more than two bolts.
[0022] When the first and second hinge bolts 34 , 36 are installed to facilitate coupling of the hinge stay 20 to the fuel tank 22 , a threaded portion 35 of the first hinge bolt 34 can extend far enough beyond the flange 28 to intersect the hinge axis A 1 , as illustrated in FIGS. 4-5 . As illustrated in FIG. 5 , when the hinge pin 18 is slid rightwardly (as shown in dashed lines), the hinge pin 18 can contact the threaded portion 35 of the first hinge bolt 34 thereby obstructing the hinge pin 18 and preventing its removal from the hinge stay 20 .
[0023] The hinge pin 18 can comprise a first end 38 and a second end 40 , as illustrated in FIGS. 2 and 5 . A cotter pin 42 can be releasably coupled to the second end 40 of the hinge pin 18 and can prevent the second end 40 of the hinge pin 18 from sliding into the hinge stay 20 . The cotter pin 42 can be selectively removed to permit the hinge pin 18 to be slid rightwardly with respect to the hinge stay 20 and the frame 16 . The first end 38 of the hinge pin 18 can include a stop portion 43 that prevents the first end 38 from sliding into the hinge stay 20 . The stop portion 43 can encourage one-way removal of the hinge pin 18 from the right side 32 of the hinge stay 20 by preventing the hinge pin 18 from being removed by sliding leftwardly. The stop portion 43 can have a greater diameter than that of the frame apertures 49 and/or the hinge stay apertures 21 . In one embodiment, as illustrated FIG. 5 , the stop portion 43 can be a washer that is affixed to the first end 38 of the hinge pin 20 (e.g., through welding). In another embodiment, the stop portion 43 can be a bulbous end formed integrally with the first end 38 of the hinge pin 18 (e.g., in a one-piece construction). In other embodiments, a stop portion can comprise any of a variety of arrangements affixed or otherwise formed on the hinge pin 18 that prevents the hinge pin 18 from sliding into a hinge stay in a particular direction.
[0024] Since the stop portion 43 prevents leftward removal of the hinge pin 18 from the hinge stay 20 , the second hinge bolt 36 might not need to intersect the hinge axis A 1 to obstruct the hinge pin 18 . Therefore, the hinge assembly 14 and the fuel tank 22 can be arranged such that the second hinge bolt 36 is offset from the hinge axis A 1 , as illustrated in FIG. 3 , and thus not positioned to obstruct the hinge pin 18 . While the embodiment of FIGS. 2-5 depicts the hinge pin 18 to be configured such that it is obstructed on the right side 32 by the first hinge bolt 34 , it will be appreciated that a hinge pin and/or hinge bolts can be configured to facilitate removal and obstruction of the hinge pin in any of a variety of other suitable configurations.
[0025] The hinge pin 18 accordingly cannot be removed from the hinge stay 20 without first removing the first hinge bolt 34 . Any attempts to remove the fuel tank 22 from the vehicle 10 by simply removing the hinge pin 18 are therefore discouraged. Instead, the fuel tank 22 must be removed from the vehicle 20 by first removing the first hinge bolt 34 . This can encourage proper disassembly of the fuel tank 22 which can reduce the risk of the fuel tank 22 being inadvertently damaged during disassembly and can additionally discourage inexperienced users from removing the fuel tank. Additionally, the first hinge bolt 34 can prevent the hinge pin 18 from being inadvertently separated from the hinge stay 20 such as when the cotter pin 42 is not installed properly.
[0026] It will be appreciated that a fuel hose (not shown) can be connected at one end to the fuel tank 22 and can be routed underneath the fuel tank 22 and near the hinge stay 20 . Removing the fuel tank 22 , rather than pivoting it upwardly, might result in kinking or could cause other damage to the fuel hose. By restricting removal of the hinge pin 18 from the hinge stay 20 with at least one of the hinge bolts (e.g., 34 ) and thus requiring detachment of the fuel tank 22 from the hinge stay 20 , removal of the fuel tank 22 can be discouraged, or at a minimum, proper precaution and greater care can be encouraged to prevent damage to the fuel hose.
[0027] Referring now to FIG. 6 , a fuel tank assembly 112 is illustrated according to another embodiment. The fuel tank assembly 112 can be similar to, or the same in many respects to the fuel tank assembly 12 shown in FIGS. 1-5 . For example, the fuel tank assembly 112 can include a hinge assembly 114 and a fuel tank 122 . The fuel tank 122 can be pivotally coupled to a frame 116 by the hinge assembly 114 . The hinge assembly 114 can include a hinge pin 118 and a hinge stay 120 . The hinge stay 120 can be releasably coupled to the fuel tank 122 by first and second hinge bolts 134 , 136 . The hinge pin 118 can include first and second ends 138 , 140 and can define a hinge axis A 11 . The second end 140 of the hinge pin 118 can be provided with a cotter pin 142 that prevents the second end 140 . The first end 138 of the hinge pin 118 , however, can be provided with a circlip 145 . When the circlip 145 is installed on the first end 138 of the hinge pin 118 , the first end 138 is prevented from sliding into the hinge stay 120 . Once the circlip 145 is removed, however, the second end 140 of the hinge pin 118 is permitted to slide into the hinge stay 120 thus permitting removal of the hinge pin 118 from a left side 130 of the hinge stay 120 . The cotter pin 142 and the circlip 145 accordingly cooperate to permit removal of the hinge pin 118 from the hinge stay 120 in either direction.
[0028] As illustrated in FIG. 6 , when the first and second hinge bolts 134 , 136 are installed, respective threaded portions 135 , 137 of the first and second hinge bolts 134 , 136 can extend far enough to intersect the hinge axis A 11 . The first and second hinge bolts 134 , 136 can accordingly obstruct the hinge pin 118 from being removed from either side. At least one of the first and second hinge bolts 134 , 136 must therefore be removed before trying to remove the hinge pin 118 from the hinge stay 120 . As illustrated in FIG. 7 , the hinge assembly 114 and the fuel tank 122 can be arranged such that the first and second hinge bolts 134 , 136 are substantially aligned with the hinge axis A 11 and thus positioned to obstruct the hinge pin 118 on both sides.
[0029] The foregoing description of embodiments and examples has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the forms described. Numerous modifications are possible in light of the above teachings. Some of those modifications have been discussed and others will be understood by those skilled in the art. The embodiments were chosen and described in order to best illustrate certain principles and various embodiments as are suited to the particular use contemplated. The scope of the invention is, of course, not limited to the examples or embodiments set forth herein, but can be employed in any number of applications and equivalent devices by those of ordinary skill in the art. Rather it is hereby intended the scope of the invention be defined by the claims appended hereto.
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A fuel tank assembly includes a hinge assembly, a fuel tank, and at least one hinge bolt. The hinge assembly includes a hinge pin and a hinge stay. The hinge pin pivotally couples the hinge stay to a vehicular frame and defines a hinge axis about which the hinge stay is pivotable with respect to a frame. The at least one hinge bolt releasably couples the hinge stay to the fuel tank such that the fuel tank is pivotable about the hinge axis. The at least one hinge bolt intersects the hinge axis and obstructs the hinge pin from being removed from the hinge stay.
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BACKGROUND OF THE INVENTION
There are numerous instances where hydrocarbon fuels become mixed with water following leakage from tanks, spills of fuels on the ground and from condensation of moisture within a tank as may occur when the fuel tank is substantially empty.
Modern gasolines are being formulated with increasing amounts of organic oxygenates, such as methyl tertiary butyl ether (mtbe), methyl tertiary amyl ether (tame), and the like. The oxygenates are more soluble in the water than are the traditional hydrocarbon components of the fuels. When water becomes contaminated with minor amounts of these organics it is desirable to remove the organic content so as to negate environmental problems. The greater affinity of the oxygenates for water leads to generally higher concentrations of the oxygenates in water than has historically been found for hydrocarbons and renders separating them from the water to increasingly lower levels mandated by regulations a difficult problem.
A traditional way for treating wastewater contaminated with volatile organics, then, is to contact the wastewater in a stripping column with a gas such as air, as disclosed e.g. in British Patent 2,035,814A. When designing the equipment for a given set of conditions the amount of contaminant that can be removed decreases as the temperature decreases.
When groundwater becomes contaminated with minor amounts of these organics, vast amounts of energy may be required to reduce the organics to a level of less than a few parts per million, and even more energy to achieve levels in the parts per billion range.
It is an object of this invention to provide an energy efficient system having the capability for continuous operation to treat significant quantities of e.g. contaminated groundwater, and to reduce the contamination by oxygenates to environmentally acceptable levels.
It is a further object to dispose of the removed oxygenates in an energy efficient as well as environmentally acceptable matter.
SUMMARY OF THE INVENTION
The invention provides a system for reducing the level of minor amounts of volatile organic contaminants from water containing such contaminants, which includes:
A) water supply means for supplying water to said system and capable of being connected to a supply of water contaminated with minor amounts of volatile organic compounds;
B) first heat exchange means having a first inlet connected to said water supply means, having a first internal volume for heating said contaminated water by indirect heat exchange with hot product water, said internal volume communicating with a first outlet, and also having a second inlet, said second inlet communicating with a second internal volume in heat exchange relation with said first internal volume, and a second outlet communicating with said second internal volume;
C) second heat exchange means disposed in heat exchange relation with a furnace, said second heat exchange means having an inlet connected to the first outlet of said first heat exchange means, and having an outlet;
D) an upright vessel containing packing or trays for contacting contaminated water with a stripping gas, said vessel having a water inlet and a gas outlet each disposed in the upper part of said vessel and having a water outlet and a gas inlet disposed in the lower part of said vessel;
E) a conduit for vessel feed water connecting the outlet of said second heat exchange means to the water inlet of said vessel;
F) a conduit for vessel product water connecting the outlet from said vessel with the second inlet of said first heat exchange means;
G) a conduit connected to the second outlet of said first heat exchange means for passing water having reduced level of volatile organic contaminants from the system;
H) means for supplying gas connected to the gas inlet of said vessel for stripping volatile organic contaminants from water in said vessel; and
I) a conduit for vessel product gas connecting the gas outlet of the vessel to the inlet of said furnace.
The invention further provides a continuous process for reducing levels of volatile organic contaminants in water and disposing of said contaminants which process comprises:
A) supplying water containing-volatile organic contaminants to a first heat exchanger and heating said contaminant-containing water by indirect heat exchange with water having levels of contaminants reduced according to the instant process;
B) passing the heated water from step A) to a second heat exchanger disposed in heat transfer relation with a furnace for further heating the contaminant containing water by indirect heat exchange;
C) stripping the heated contaminated water with air, to obtain hot product water having reduced contaminants and a contaminated air stream;
D) passing said contaminated air stream to the inlet of said furnace and combusting the contaminants in said furnace; and
E) passing the hot product water from step C) to said first heat exchanger to cool the product water.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further explained with reference to the accompanying drawings wherein:
FIG. 1 is a schematic representation of a preferred embodiment of the system of this invention.
FIG. 2 is a graph comparing the removal of methyl tertiary butyl ether from water containing 0.5 per cent by weight of said ether at various rates of stripping air to water flow and the influence of temperature on the removal rate as well.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention provides an inexpensive and flexible system enabling comparatively low energy costs for remediating water which has been contaminated with oxygenates. The system has the capability to be effective for reducing the levels of contamination in the treated water product to or below levels generally considered to be acceptable for return to the environment.
Referring now to the drawings, FIG. 1 is a schematic representation of a system embodying this invention, and is provided to show the various functions that will be employed without regard to scale. Contaminated water from a source not shown is fed to the system via line 10 to water supply means, pump 12. The contaminated water passes through conduit 14 to the first inlet 16 of heat exchanger 18 having an internal volume where it is heated by indirect heat exchange with "clean" i.e. decontaminated water product from the system. Any known conventional unfired heat-transfer equipment design, such as a shell and tube exchanger or plate and frame heat exchanger may be used so long as there is no leakage or other commingling of contaminated water into the clean water. The heated water passes from first heat exchanger 18 first outlet 20 through line 22 to second heat exchanger 24 disposed in heat transfer relation to fired furnace 26. Second heat exchanger 24 may be any conventional fired heat-transfer equipment. The furnace is fired at a rate to achieve any desired elevated temperature of the contaminated water. The heated contaminated water is passed from second heat exchanger 24 via conduit 28 to the upper part, and preferably the topmost part of stripping vessel 30.
Stripping vessel 30 may be a trayed column, but preferably is a packed column containing any conventional packing, such as, for example Raschig rings, Lessing rings, Berl saddles, Intalox saddles, Tellerettes, Pall rings and the like, and preferably contains a high surface area packing such as marketed under the trade name JAEGER Tripacks. Generally best results are obtained by the use of tall, small diameter columns. The contaminated heated water flows downwardly through the packing in stripping vessel 30 and countercurrently contacts stripping gas supplied to the bottom of said vessel from gas supply means 32 via line 34.
Gas supply means 32 may comprise any conventional gas supply source such as bottles of nitrogen, carbon dioxide and the like. However, a conventional air blower which can supply clean ambient air as the stripping gas is preferred. In a preferred embodiment an optional valved conduit 35 disposed in heat transfer relation with the hot effluent exhaust from the furnace is connected to the intake of blower 32 for heating at least a part of the air intake to the air blower to have the air entering the stripper at a temperature substantially the same as the temperature of the water to prevent a large drop in temperature during the stripping process. The water, after having the volatile organics stripped out by the stripping gas, is passed from the bottom of stripping column 30 via line 36 to second inlet 37 of first heat exchanger 18 where it is cooled, by transfer of heat by indirect exchange to additional contaminated water passing through said first heat exchanger 18. The "clean" cooled water is passed from first heat exchanger 18, outlet 38 and line 39 for reuse or release to a receiving body of water such as groundwater, a lake, stream or the like.
The stripping gas containing the organics removed from the water is passed from the top of stripping vessel 30 via conduit 40 to the inlet of furnace 26 where the organics are incinerated to carbon dioxide and water which are released to the atmosphere admixed with the furnace flue gas. As will be known to those skilled in the art the stripping gas in line 36 will contain appreciable water vapor.
In a preferred embodiment an optional phase separator 42 also known as a knockout pot is installed to remove any condensed water in line 40 before the stripped gas enters furnace 26. The separated water is passed from phase separator 42 via line 44 and recycled with the feed water entering the system via line 10. In this manner any organics contained therein are disposed of without adverse impact on the environment. In a properly designed system this recycle of separated water would amount to less than about one percent of the fresh contaminated water fed to the system and would not significantly impact either cost of the system or the amount of energy required to operate the process.
The invention will now be illustrated with reference to the following illustrative embodiment.
ILLUSTRATIVE EMBODIMENT
With reference to FIG. 1 contaminated water containing about 20,000 parts per billion (ppb) of mtbe from a surface of groundwater source (not shown) and having a temperature of about 40° F. is connected to the system according to the invention via conduit 10 and is pumped via pump 12 at a rate of 70 gallons per minute (gpm) via conduit 14 to first inlet 16 of unfired heat exchanger 18. The contaminated water is heated by indirect heat exchange to a temperature of about 94° F. and is passed via first exchanger outlet 20 and line 22 to second heat exchanger 24 which is heated by furnace 26 having a rating of about 780,000 BTU/hr. The contaminated water is heated to a temperature of about 113° F. and is passed via line 28 to the top of stripping vessel 30. Stripping vessel 30 is a conventional packed column filled with a packing commerically available under the trade name JAEGER Tripacks. The stripping vessel will preferably have a height to diameter ratio above about 7, e.g. a packing height of about 30 ft. and a diameter of about 2 ft. The water passes downwardly in stripping vessel 30 in countercurrent flow to air flow of 500 standard cubic feet per minute (scfm) fed to the bottom of stripping vessel 30 via line 34 from air blower 32. The ambient air has a temperature of about 32° F. and the effect of contact and stripping is that the water has been cleaned, i.e. has substantially reduced levels of mtbe on the order of about 50 ppb or less and the temperature is lowered on the order of about 5° F. to about 108° F. The clean water is passed from stripping vessel 30 via conduit 36 to second inlet 37 of first heat exchanger 18 where the temperature is lowered to about 54° F. and is passed via second outlet 38 of first heat exchanger 18 and line 39 for use or return to groundwater.
The air now contaminated with the volatile organics stripped from the water exits stripper vessel 30 and is carried by conduits 40 and 42 to the inlet of furnace 26 where it serves as part of the oxidant, and the volatile organics are incinerated to harmless carbon dioxide and water vapor. Preferably, the contaminated air in lines 40 and 42 is passed through optional phase separator 44 to separate any entrained water which in this embodiment would be less than about 0.3 gpm, and the separated water, which will still contain some volatile organics, is passed through valved conduit 46 and line 10 to recycle to the system.
As an alternate embodiment line 40 is disposed in heat transfer relation to the exhaust gas from furnace 26 as shown, whereby less fuel will be required to heat the furnace to a temperature of 1400° to 1600° F. for a period of about one-half second, to ensure destruction of the stripped contaminates entering the furnace with the air supplied via lines 40 and 42.
It is an advantage of the system of the invention that it provides flexibility to minimize the thermal and electrical energy required to remediate water contaminated with volatile organics to clean i.e. environmentally acceptable condition. FIG. 2 graphically compares the calculated effect of different air to water ratios for air stripping mtbe from water heated to different temperature in a stripping column having a diameter of 2 ft. and having a packed height of 15 ft. with 2-inch JAEGER Tripack packing. With the instant system it is possible to optimize the the thermal and electrical input to achieve the desired results for any particular contaminated feed, recognizing that part of the thermal energy input is obtained from the removed contaminants.
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A system is disclosed for reducing the level of minor amounts of volatile organic contaminants, from contaminated water, which includes pump means to feed water from the body of contaminated water to the system, a plurality of heating means to raise the temperature of the water, a contact vessel to contact the heated water with gas to strip the volatile contaminants from the water, gas supply means to provide stripping gas to the vessel, and means to pass the removed volatile contaminants to a furnace for disposal by combustion.
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This application is a continuation of application Ser. No. 08/104,104, filed Aug. 12, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to novel polymers containing conjugated double bonds which are built up from carbocyclic and/or heterocyclic rings, and each of these rings is linked to the adjacent ring at two bonding points in the manner of a conductor (ladder polymers).
2) Prior Art
Polypyrroles and copolymers thereof are described, inter alia, in EP-A-99 984. EP-A-218 093 outlines polymers containing conjugated double bonds in which (hetero)aromatic rings are each bonded to one another via a carbon atom
Ladder polymers containing a conjugated double bond are formed, as is known, on graphitization of polyacrylonitrile or on pyrrolysis of this polymer, in the presence of dehydrogenating catalysts and are known as "black Orlon" ("ORLON" is a registered trademark of E. I. Du Pont de Nemours Co.). According to the constitution proposed for this polymer, it comprises dihydropyrrole units which are bonded to each adjacent unit both by a methine group and by a nitrogen atom. Intramolecular ring closure in poly(vinyl methyl ketone) forms a polymer comprising tetrahydrobenzene units which are bonded to each adjacent unit both via a methylene group and via a methine group.
The object of the present invention was to synthesize novel substances, in particular novel intermediates for the preparation of electroconductive polymers or polymers having nonlinear optical properties. A further object of the present invention was to provide a novel process for the preparation of polymers. A further object of the present invention was to provide novel polymers. A final object of the present invention was to produce thin layers on substrates which are suitable for use of the polymers for optical, electrooptical and electronic purposes.
SUMMARY OF THE INVENTION
The abovementioned objects are achieved by the present invention which provides polymers having an extended system of conjugated double bonds, built up from homocyclic and/or heterocyclic rings which are each bonded to one another in pairs, so that each ring is linked to the adjacent ring through two vicinal ring atoms, wherein one of these links is formed by a chemical bond to a ring atom of the adjacent ring and the other is formed via a carbon, oxygen, nitrogen or sulfur atom to an atom of the adjacent ring which is vicinal to the abovementioned ring atom.
The polymers according to the invention differ from the above ladder polymers described as the prior art through the fact that the units are bonded to one another in each case both through a chemical bond and via an atom as bridge. This type of linking causes the formation of a five-membered ring and not--as in the known ladder polymers--a six-membered ring.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polymers according to the invention are preferably built up from units of the formula (1) ##STR1## in which D and M, independently of one another, are each a chemical bond or a radical of the formula C--R in which C is a carbon atom, and
R are identical or different radicals, namely hydrogen atoms or optionally substituted C 1 - to C 20 -hydrocarbon radicals,
E and T, independently of one another, are each an oxygen or sulfur atom, a radical of the formula N--R, or, if the radical D or M belonging to the same ring is a radical of the formula C--R, may alternatively be a radical of the formula C--R, and in each ring one of the radicals
G and L is a single chemical bond, and in each ring the radical of G and L which is not a single bond is a radical of the formula CR 2 , where at least one of the radicals R is preferably a hydrogen atom, or can be prepared by dehydrogenation of polymers built up from units of the formula (1).
Preferred polymers according to the invention are those built up from units of the formulae (4), (5) and/or (6) or the polymers which can be prepared from these polymers by removal of two hydrogen atoms per unit (dehydrogenation). ##STR2##
It is preferred if one of the radicals G and L in each ring in the above formula (1) is a chemical bond, while the other radical is in each case a radical of the formula CHR.
The radicals D and E are preferably radicals of the formula C--R.
The radicals M and T are preferably radicals of the formula C--R.
Preferred polymers according to the invention are those built up from units of the formulae (7), (8), (9), (10), (11) and/or (12). ##STR3##
Examples of radicals R are hydrogen atoms; alkyl radicals, such as the methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and tert-pentyl radicals, hexyl radicals, such as the n-hexyl radical, heptyl radicals, such as the n-heptyl radical, octyl radicals, such as the n-octyl radical and isooctyl radicals, such as the 2,2,4-trimethylpentyl radical, nonyl radicals, such as the n-nonyl radical, decyl radicals, such as the n-decyl radical, dodecyl radicals, such as the n-dodecyl radical and octadecyl radicals, such as the n-octadecyl radical; alkenyl radicals, such as the vinyl and allyl radicals; cycloalkyl radicals, such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radicals; aryl radicals, such as the phenyl, naphthyl, anthryl and phenanthryl radicals; alkaryl radicals, such as o-, m- and p-tolyl radicals, xylyl radicals and ethylphenyl radicals; and aralkyl radicals, such as the benzyl radical and the alpha- and β-phenylethyl radicals.
Examples of substituted radicals R are cyanoalkyl radicals, such as the β-cyanoethyl radical, and halogenated hydrocarbon radicals, for example haloalkyl radicals, such as 3,3,3-trifluoro-n-propyl radical, the 2,2,2,2',2',2'-hexafluoroisopropyl radical, and the heptafluoroisopropyl radical, and haloaryl radicals, such as the o-, m- and p-chlorophenyl radicals.
The polymers according to the invention may contain dopes. Addition of such known dopes allows the conductivity of the polymers to be increased.
Examples of dopes are alkali metals, such as sodium or potassium; protonic acids, such as H 2 SO 4 , HClO 4 , H 2 Cr 2 O 7 , HI and HNO 3 ; Lewis acids, such as SbCl 5 , AsCl 5 , TiCl 4 , FeCl 3 , SnCl 4 , ZnCl 2 and AsF 5 , and halogen, such as, for example, iodine. Treatment of the compositions according to the invention with dopes (n) is generally carried out by allowing the vapors or solutions of the dope to act on the polymers. This is usually carried out at from about 10° to 30° C., usually with exclusion of moisture, frequently with exclusion of air. The doped polymers preferably contain from 0.01 to 30% by weight, in particular from 0.1 to 20% by weight, of dope.
The polymers according to the invention may also be finely distributed in a further polymer. They may be distributed, inter alia, in the matrix of a thermoplastic polymer. The preparation of such polymer mixtures is described in EP-A-357 059. The distribution of the polymers according to the invention in the matrix of a further polymer allows the processing properties and physical properties of the polymers according to the invention to be improved.
The polymers according to the invention can be prepared by
(A) polymerizing at least one compound of the formula (2) ##STR4## with at least one compound of the formula (3) ##STR5## in the presence of at least one heavy metal and/or compounds thereof, where, in the above formulae (2) and (3), two of the radicals
R 1 , R 2 , R 3 and R 4 are halogen atoms, preferably bromine atoms, and the other two of the radicals R 1 , R 2 , R 3 and R 4 are radicals of the formula --C(R)═O, and two of the radicals
R 5 , R 6 , R 7 and R 8 are radicals of the formula --B(OR) 2 , and the two other radicals R 5 , R 6 , R 7 and R 8 are each as defined for the radical R, and D, E, M, R and T are as defined in claim 2,
(B) reducing the carbonyl groups to carbinol groups in a manner known per se,
(C) condensing the resultant polymer with the carbinol groups with cyclization, and optionally
(D) dehydrogenating the resultant polymer in a manner known per se, and, if desired,
(E) adding dopes to the polymer.
The heavy metals and/or compounds thereof employed in step (A) are preferably the metals and metal compounds known as hydrogenation catalysts, in particular palladium and nickel or compounds thereof.
The reduction in step (B) is preferably effected by a metal hydride or an organometaliic compound. Preferred metal hydrides are lithium hydride, sodium hydride, potassium hydride, lithium aluminum hydride and sodium borohydride. Preferred organometallic compounds are metal alkyl compounds, such as n-butyllithium, sec-butyllithium, t-butyllithium, phenyllithium, and Grignard reagents.
Step (C) is preferably carried out in the presence of at least one Bronstedt or Lewis acid, in particular in the presence of a Lewis acid. Examples of Lewis acids are BF 3 , AlCl 3 , TiCl 4 , SnCl 4 , SO 3 , PCl 5 , POCl 3 , FeCl 3 and hydrates thereof and ZnCl 2 ; examples of Bronstedt acids are hydrochloric acid, hydrobromic acid, sulfuric acid, chlorosulfonic acid, phosphoric acids, such as ortho-, meta- and polyphosphoric acids, boric acid, selenous acid, nitric acid, acetic acid, propionic acid, haloacetic acids, such as trichloro- and trifluoroacetic acid, oxalic acid, p-toluenesulfonic acid, acidic ion exchangers, acidic zeolites, acid-activated bleaching earths, acid-activated carbon black, hydrogen fluoride, hydrogen chloride and the like.
Step (D) can be carried out in the presence of known oxidants. These oxidants may also be dopes with an oxidative action, which makes further doping superfluous. Step (D) is preferably carried out under a protective gas in order to prevent contact with oxygen during the reaction.
The process according to the invention can be carried out in the presence or absence of solvents. If solvents are used, solvents or solvent mixtures having a boiling point or boiling range of up to 120° C. at 0.1 MPa are preferred. Examples of such solvents are ethers, such as dioxane, tetrahydrofuran, diethyl ether and diethylene glycol dimethyl ether; chlorinated hydrocarbons, such as dichloromethane, trichloromethane, tetrachloromethane, 1,2-dichloroethane and trichloroethylene; hydrocarbons, such as pentane, n-hexane, hexane isomer mixtures, heptane, octane, naphtha, petroleum ether, benzene, toluene, and xylenes; ketones, such as acetone, methyl ethyl ketone and methyl isobutyl ketone; carbon disulfide and nitrobenzene, or mixtures of these solvents.
The term solvent does not mean that all reaction components must dissolve therein. The reaction can also be carried out in a suspension or emulsion or one or more reactants. The reaction can also be carried out in a solvent mixture having a miscibility gap, where in each case at least one reactant is soluble in each of the mixture phases.
The polymers according to the invention have significant electroconductivity and have nonlinear optical properties. They can be employed in electrical, electronic and opto-electronic components.
In the examples below, unless stated otherwise,
a) all amount data are based on the weight;
b) all pressures are 0.10 MPa (abs.);
c) all temperatures are 20° C.;
d) the gel permeation chromatograms are calibrated using polystyrene.
EXAMPLES
Example 1
(A) 5 ml of 2N sodium carbonate solution are added under an inert gas to a solution of 0.725 g of 4,4"-didecyl-2',5'-dibromoterephthalophenone (1 mmol) and 0.334 g of 2,5-dihexyl-1,4-phenylenediboronic acid (1 mmol) in 5 ml of toluene. The mixture prepared in this way was heated under reflux. 30 mg of tetrakis(triphenylphosphino)palladium(0) (0.026 mmol) in 5 ml of toluene were subsequently added. After the mixture had been refluxed for 24 hours, the polymer formed was precipitated by pouring into acetone, washed until acidic and taken up in a little toluene. Drying of the solution, evaporation and reprecipitation using acetone gave 535 mg of the polymer of the formula (13) below, in which R is n-decyl and R' is n-hexyl.
Yield: 66% of theory.
Elemental analysis: calculated: C: 86.08%; H: 9.96%; found: C: 85.85%; H: 10.19%;
Molecular weight according to gel permeation chromatogram:
Number average (M n ): 6,500; weight average: (M w ): 8,700. ##STR6##
(B) 200 mg (0.024 mmol) of the polymer prepared as in (A) were reduced using LiAlH 4 in 40 ml of toluene/tetrahydrofuran (1:1). After the mixture had been stirred at room temperature for 30 minutes, the excess hydride was carefully decomposed and the product was washed with 2N hydrochloric acid and with water. The organic phase was dried, the solvent mixture was removed by distillation, and the polymer was taken up in a little tetrahydrofuran and precipitated in water, giving 167 mg of the polymer of the formula (14) below.
Yield: 84% of theory.
Elemental analysis: calculated: C: 85.66%; H: 10.41%; found: C: 84.12%; H: 10.59%;
Molecular weight according to gel permeation chromatogram:
Number average (M n ): 5,100; weight average: (M w ): 8,000. ##STR7##
(C) 76 mg (0.0934 mmol) of the polymer obtained as in (B) were dissolved in 50 ml of dichloromethane, and 300 mg (2.11 mmol) of boron trifluoride diethyl etherate were added. After 5 minutes, 20 ml of ethanol and finally 50 ml of water were added with stirring. The organic phase was washed, dried and evaporated. Precipitation by means of acetone gave 62 mg of a polymer of the formula (15) below.
Yield: 85% of theory.
Elemental analysis: calculated: C: 89.63%; H: 10.37%; found: C: 88.77%; H: 11.20%;
Molecular weight according to gel permeation chromatogram:
Number average (M n ): 6,200; weight average: (M w ): 8,300. ##STR8##
(D) 50 mg (0.0643 mmol) of the polymer obtained as in (C) were dissolved in 20 ml of dichloromethane, and a 0.1N solution of SbCl 5 in dichloromethane was added until the intense violet coloration of the solution which occurred initially had disappeared to give a pale greenish coloration. 20 ml of water were then added under nitrogen, and the mixture was stirred well for 10 minutes. The organic phase was washed with water, filtered and dried. Work-up of the solution gave the polymer of the formula (16) below as a violet film or precipitate. ##STR9##
Example 2
(A) A solution of 0.725 g (1 mmol) of 4,4"-didecyl-4',6'-dibromoisophthalophenone and 0.334 g (1 mmol) of 2,5-dihexyl-1,4-phenylenediboronic acid in 5 ml of toluene was added under an inert gas to 5 ml of 2N sodium carbonate solution. The mixture was refluxed, and 30 mg (0.026 mmol) of tetrakis(triphenylphosphino)palladium(0) in 5 ml of toluene were then added. After the mixture had been refluxed for 24 hours, it was poured into methanol, the polymer thus precipitated was taken up in a little toluene, and the solution was dried and evaporated. Reprecipitation by means of methanol gave 620 mg of the polymer of the formula (17) below (R=n-decyl; R'=n-hexyl).
Yield: 77% of theory.
Molecular weight according to gel permeation chromatogram:
Number average (M n ): 5,200; weight average: (M w ): 7,100. ##STR10##
(B) A suspension of 210 mg (5.52 mmol) of LiAlH 4 in tetrahydrofuran was added dropwise to a solution of 600 mg (0.741 mmol) of the polymer prepared as in (A) in 50 ml of toluene. After the mixture had been stirred at room temperature for 30 minutes, the excess hydride was carefully decomposed, and the mixture was washed with 2N hydrochloric acid and with water. The organic phase was dried, the solvent mixture was removed by distillation, and the polymer was taken up in a little tetrahydrofuran and precipitated in water, giving 530 mg of the polymer of the formula (18) below.
Yield: 88% of theory. ##STR11##
(C) 500 mg (0.615 mmol) of the polymer prepared as in (B) were dissolved in 30 ml of dichloromethane, and 1.8 g (12.7 mmol) of boron trifluoride diethyl etherate were added. After 5 minutes, 10 ml of ethanol were added to the mixture with stirring, and finally 50 ml of water were added. The organic phase was washed, dried and evaporated. 430 mg of the polymer of the formula (19) below were precipitated from acetone.
Yield: 90% of theory. ##STR12##
(D) A 0.1N SbCl 5 solution in dichloromethane was added to a solution of 50 mg (0.0643 mmol) of the polymer prepared as in (C) in 20 ml of dichloromethane until the pale violet coloration of the solution which occurred initially disappeared to give a green coloration. 20 ml of water were then added under nitrogen, and the mixture was stirred well for 20 minutes. The organic phase was separated off, washed with water, filtered and dried. Work-up of the solution gave the polymer of the formula (20) below as a pale violet film or precipitate. ##STR13##
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The present invention relates to polymers with an extended system of conjugated double bonds constructed as homo and/or heterocyclic rings which are interlinked in pairs so that one ring is joined to the neighboring one at two adjacent atoms in the ring, in which one of these connections is made by a chemical bond to a ring atom of the neighboring ring and the other via a carbon, nitrogen, oxygen or sulphur atom to an atom of the neighboring ring adjacent said ring atom, their production and use in electrical, electronic and opto-electronic components.
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