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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National Stage Application of International Application No. PCT/EP2008/064162 filed Oct. 21, 2008, which designates the United States of America, and claims priority to German Application No. 10 2007 053 257.3 filed Nov. 8, 2007, the contents of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The invention relates to a method and a device for checking a valve lift switchover process in a motor vehicle.
BACKGROUND
[0003] Electrohydraulic valve lift switchover systems are generally known from the prior art. An example of an electrohydraulic valve lift switchover system is the VARIO CAM PLUS system of the company INA. This is a two-stage valve lift switchover system in which a locking element is actuated in a control bucket tappet or a rocker arm by means of oil pressure against a spring and by this means, depending on the activation or deactivation status, it is possible to switch between two different valve lift curves. To effect the switchover an electromagnetic valve (3/2-way valve) located in the oil circuit is supplied with current, whereupon the valve opens. The oil pressure builds up and the locking element moves against the spring until the locking operation is completed. When the electromagnetic valve is closed again, the oil pressure decreases via a leakage line and the locking element, activated by the spring force, slides back into its home position.
[0004] In order to guarantee a comfortable, jerk-free and emission-neutral switchover it must be ensured that the locking process takes place in a defined operating segment that is known to the engine control unit, since measures that accompany the valve lift switchover, such as the adjustment of the throttle valve and the camshaft phasers as well as the adjustment of ignition and injection, must be performed at the right time or, as the case may be, in the right segment. This plays an all the more important role if a changeover in operating mode is initiated simultaneously with the valve lift switchover, for example from an SI (Spark Ignited) operating mode into a CAI (Controlled Auto-Ignition) operating mode in which a homogeneous self-ignition takes place. The system is extremely complex and the multiplicity of influencing variables inevitably harbors the risk of switchover errors.
SUMMARY
[0005] According to various embodiments, a method and a device can be provided which reduce the occurrence or number of switchover errors.
[0006] According to an embodiment, a method for checking a valve lift switchover of an engine may comprise the steps of: a) determining whether a switchover error and/or an external event has occurred which can affect the correct operation of the valve lift switchover function, b) inhibiting the valve lift switchover if a switchover error and/or such an external event has occurred, c) activating and checking the valve lift switchover during at least one noncritical operating state, d) releasing the valve lift switchover if the valve lift switchover exhibits no abnormalities during the check.
[0007] According to a further embodiment of the method, step a) may have the step of: a1) setting at least one flag in an engine control unit for controlling the valve lift switchover when a switchover error and/or an external event has occurred. According to a further embodiment of the method, the information that an external event has occurred can be forwarded to the engine control unit, for example via a diagnostic line, a CAN data line, a LIN data line or another suitable interface. According to a further embodiment of the method, at step b) the valve lift switchover may be inhibited for all operating states. According to a further embodiment of the method, at step d) the valve lift switchover can be released for all operating states if the valve lift switchover exhibits no abnormalities during the check. According to a further embodiment of the method, a noncritical operating state may include, for example, operating states such as a deceleration fuel cutoff phase or operating points in which essentially no torque jump or only a slight torque jump is to be expected during the valve lift switchover. According to a further embodiment of the method, at step c) the checking of the valve lift switchover can be performed in a noncritical operating state in that, for example, a switch is made back and forth between two camshaft profiles at least once or a number of times, the valve lift switchover being checked each time for correct operation in the process, its operation being analyzed, for example, on the basis of at least one or more than one parameter, such as the oil pressure curve, the switching timing, the switching sequence, the cylinder pressure curve, etc. According to a further embodiment of the method, at step d) the valve lift switchover can be released for all operating states if the valve lift switchover exhibits no abnormalities during the check. According to a further embodiment of the method, if it is established during the checking of the valve lift switchover at step c) that the valve lift switchover is exhibiting abnormalities during the check, at least one or more than one control parameter can be adjusted accordingly in order to substantially remove the abnormalities in the valve lift switchover, one control parameter relating, for example, to the control of the switching timing. According to a further embodiment of the method, if an adjustment of at least one or more than one control parameter was made, the valve lift switchover may be subsequently activated initially only for at least one noncritical operating state and a check of the valve lift switchover is performed in said operating state. According to a further embodiment of the method, an external event which can affect the correct operation of the valve lift switchover function may include, for example, at least one of the following events or combination of events or, as the case may be, input variables: an oil temperature, an oil change, a visit to a repair shop in conjunction with, for example, work on the valve train assembly, work on components relevant to the valve lift switchover, the replacement of components relevant to the valve lift switchover, work on the oil circuit, for example the oil pump, the filter, the lines, etc.
[0008] According to a further embodiment, a device for checking a valve lift switchover of an engine may have: a) an arrangement for determining whether a switchover error and/or an external event has occurred which can affect the correct operation of the valve lift switchover function, b) an arrangement for inhibiting the valve lift switchover, the arrangement inhibiting the valve lift switchover if a switchover error and/or such an external event was detected by the arrangement for detecting a switchover error or an external event, c) an activation and checking arrangement which activates the valve lift switchover for at least one noncritical operating state and checks it during said operating state, the activation and checking arrangement releasing the valve lift switchover if the valve lift switchover exhibits no abnormalities during the check.
[0009] According to a further embodiment of the device, the arrangement for determining whether a switchover error and/or an external event has occurred which can affect the correct operation of the valve lift switchover can be connected to an engine control unit and sets a flag if a switchover error or an external event occurs, the arrangement being connected for this purpose to the engine control unit via, for example, a diagnostic line, a CAN data line, a LIN data line or another suitable interface. According to a further embodiment of the device, if the activation and checking arrangement establishes during the checking of the valve lift switchover that the valve lift switchover is exhibiting abnormalities during the check, an adjustment arrangement for adjusting control parameters may adjust at least one or more than one control parameter accordingly in order to substantially remove the abnormalities in the valve lift switchover. According to a further embodiment of the device, the control arrangement may control, for example, the switching timing as a control parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention is now explained in more detail with reference to the attached drawing, in which:
[0011] FIG. 1 shows a flowchart of the valve lift switchover according to various embodiments.
DETAILED DESCRIPTION
[0012] According to various embodiments, a check is performed on a valve lift switchover of an engine, wherein it is determined initially whether a switchover error and/or an external event have/has occurred which can affect the correct operation of the valve lift switchover function. If at least one of said events occurs, the valve lift switchover is initially disabled or inhibited. Subsequently the valve lift switchover is activated in a noncritical state and checked. If the result of the check is that the valve lift switchover exhibits no abnormalities during the noncritical operating state, the valve lift switchover is enabled or released once more.
[0013] This has the advantage that the occurrence and number of switchover errors can be reduced by virtue of the fact that a check of the valve lift switchover takes place at an early stage, when, for example, a first switchover error has occurred. In this case the valve lift switchover is allowed or activated only in a noncritical operating state, whereas the valve switchover is blocked in the other operating states. In this way the occurrence of further switchover errors can be prevented.
[0014] In a further embodiment, the valve lift switchover is inhibited for all operating states if a switchover error occurs or an external event is present which can potentially affect the valve lift switchover in a negative manner. In this way it can be ensured that, for example, no further switchover errors can occur until it has been clarified whether a (single) switchover error that occurred was coincidence or whether an error is present in the valve lift switchover.
[0015] In a further embodiment, the valve lift switchover is released again for all operating states, including also for the critical operating states if it has been established during the check that the valve lift switchover has exhibited no abnormalities. It is thus ensured that when the check has been completed and no functional errors have been revealed the valve lift switchover can be performed again to the full extent.
[0016] According to a further embodiment, a noncritical operating state includes, for example, operating states such as a deceleration fuel cutoff phase or operating points in which essentially no torque jump or only a slight torque jump is likely during the valve lift switchover. Such operating states have the advantage that a check or testing of the valve lift switchover can be performed so as to be scarcely noticeable to the driver, for example, with the result that the driver's driving experience is not adversely affected by the check.
[0017] In another embodiment, a check of the valve lift switchover is performed, for example, by switching back and forth between two camshaft profiles at least once or a number of times. In this case the valve lift switchover function is checked each time in respect of its correct operation, the latter being determined, for example, on the basis of at least one or more than one parameter, such as the oil pressure curve, the switching timing, the switching sequence and/or the cylinder pressure curve. In this way it can be easily and reliably determined whether an actual error is present during the valve lift switchover or not.
[0018] In a further embodiment, if, during the checking of the valve lift switchover, it is established that the valve lift switchover exhibits abnormalities during the check, at least one parameter is adjusted in order to substantially remove the abnormalities in the valve lift switchover. For example, if it is established that the valve lift switchover takes place too early or too late, the switching timing, for example, is correspondingly adjusted as the parameter. In this way it is possible not only to determine an error in the valve lift switchover, but also to rectify said error during the operation of the vehicle.
[0019] In another embodiment, following an adjustment of the parameter or parameters the valve lift switchover is initially activated only for at least one noncritical operating state and a new check of the valve lift switchover is performed. If the valve lift switchover thereafter no longer exhibits any abnormalities, the valve lift switchover can be released for all operating states. In this way it can be ensured that a valve lift switchover is enabled only when the error has been reliably removed. Otherwise a fresh adjustment of at least one parameter is carried out. In this case this cycle can be repeated a number of times if necessary before, after a specific number of cycles for example, an error message is issued to the driver in which it is stated that an error has occurred during the valve lift switchover and the driver should seek out a repair shop since the error cannot be corrected.
[0020] FIG. 1 shows a flowchart for performing a valve lift switchover. In this case it is initially determined at a step S 1 whether a (single) switchover error has occurred and/or whether another event is present which is having an effect on the valve lift switchover process.
[0021] In the case of such potential influencing variables a distinction is made, for example, between engine-internal and external influencing variables. Engine-internal influencing variables affecting the valve lift switchover process which can cause a (single) switchover error are, for example:
[0022] Oil temperature, oil foaming, oil thinning by fuel, occurrence of a leak, occurrence of wear and tear, aging, running-in effects of system components, deposits in the oil galleries, a blocked or clogged oil filter, etc.
[0023] With the exception of, say, the oil temperature, most of the aforementioned influencing variables are largely variables that are unknown to the engine control unit. Their effect on the valve lift switchover usually does not manifest itself until a switching error actually occurs.
[0024] Furthermore, external influencing variables affecting the valve lift switchover or external events which can have a negative effect on the valve lift switchover are, for example, the following:
an oil change a visit to the repair shop in conjunction with: work on the valve train assembly and/or components relevant to the valve lift switchover, replacement of components relevant to the valve lift switchover, work on the oil circuit, for example the oil pump, the filter, the lines, etc.
[0027] When such work is carried out on the engine, this information is communicated to the engine control unit (ECU). This is accomplished via, for example, one or more diagnostic lines (K line), CAN buses, LIN buses or via other suitable interfaces.
[0028] At a step S 2 , a marker or flag is therefore set in the engine control unit (ECU) if a switchover error occurs or if at least one external event occurs which can have an effect, i.e. a negative effect, on the valve lift switchover process.
[0029] If it is reported to the engine control unit (ECU), for example, that work has been carried out on the valve lift switchover, a marker or flag “work carried out on the valve lift switchover” is set. As soon as the flag has been set at step S 2 the valve lift switchover is blocked as a preventive measure at a next step S 3 . The same applies if a switching error occurs; the latter can likewise be reported to the engine control unit and a marker or flag set.
[0030] Next, at a step S 4 , the valve lift switchover is activated only during noncritical operating states, while remaining blocked during critical operating states. At a step S 5 , the switchover is tested for problem-free operation in the noncritical driving operating states and diagnosed.
[0031] A noncritical operating state is, for example, the deceleration fuel cutoff phase, in which a driver takes his/her foot off the accelerator pedal, for example. In the deceleration fuel cutoff phase essentially no active torque is demanded of the engine and substantially no fuel is injected. Further noncritical operating states arise, for example, in operating points at which essentially no torque jump or only a slight torque jump is to be expected during the valve lift switchover. In other words, in such operating points there is virtually or substantially torque neutrality. In said states a switchover is made back and forth between two camshaft profiles, for example, at least once or if possible a number of times and in the process the valve lift switchover function is checked in respect of its correct operation. The effect of the different valve lift curves on the engine braking torque and the impact on driving comfort during the cutoff phase are largely negligible or, as the case may be, can be eliminated through adjustment of the throttle valve setting, with the result that the driver experiences no unpleasant driving sensation due to the check.
[0032] If no abnormalities in the valve lift switchover manifest themselves during the testing or checking phase (step S 6 ), it is to be assumed that the external event that occurred, in the present example the work on the valve lift switchover, has no negative effect on the switching system. This applies analogously if, for example, a switching error occurred previously. If it is established in this case that no abnormalities have arisen during the testing phase either, it is assumed that the switching error that occurred was coincidental.
[0033] At a step S 7 , the valve lift switchover function is thereupon released again for all engine operating states, including also for the critical operating states.
[0034] If, on the other hand, it is established at step S 8 that abnormalities in the switchover manifest themselves during the testing and checking of the switchover function for problem-free operation in the noncritical driving operating states, suitable measures are taken at a step S 9 .
[0035] In other words, if an anomalous behavior manifests itself during the valve lift switchover (step S 8 ), for example in the form of, say, a change in oil pressure buildup or decrease, a change in the switching timing, a change in the cylinder pressure buildup, or a change in the switchover sequence of the cylinders, etc., then measures must be taken. The same applies if the supposed switchover error occurs repeatedly. In this case a measure is taken at step S 9 in that at least one or more than one parameter relevant to the valve lift switchover or at least one or more than one control parameter are adjusted or adapted.
[0036] If the valve lift switchover takes place too early or too late during the check, the switching timing, for example, is adjusted as the parameter in order to correct the valve lift switchover in a suitable manner so that it no longer manifests abnormalities during a next check. If, on the other hand, it is established during the checking of the valve lift switchover, for example, that no valve lift switchover has taken place at all, even though such a switchover should have taken place in the noncritical operating state, then the valve lift switchover remains blocked, since in this case an error is present which it is no longer possible to rectify by means of an adjustment of the switching timing.
[0037] Furthermore an error pattern of the cylinders can also be analyzed during the checking of the valve lift switchover. If, for example, a valve lift switchover always occurs late in the case of the same cylinder, the sequence of the cylinders during switching, for example, can be changed as the parameter. In this case the cylinder can now be controlled in such a way that it has more time for switching, for example, in that it is switched, not as the first, but as the last cylinder. If the error occurs again at the next checking step, in spite of a previous adjustment of the cylinder switching sequence, it can be inferred from this that an error is present at the cylinder. In this case a warning signal can be output to the driver indicating that the valve lift switchover is defective and he/she should visit a repair shop.
[0038] Furthermore the error can additionally be stored so that it can be retrieved and analyzed in a repair shop, for example.
[0039] After adjustment of at least one control parameter relevant to the valve lift switchover at step S 9 , the flowchart therefore returns to step S 4 , at which the valve lift switchover is initially activated again only during noncritical operating states. At the following step S 5 , the switchover process is tested and checked once again. Only if the result of the testing and checking is that the switchover exhibits no abnormalities is the valve lift switchover released for all operating states at step S 7 . Otherwise control parameters relevant to the valve lift switchover must continue to be adjusted (step S 9 ). In this case the step of checking and readjustment can be performed a predefined number of times. If an abnormality of the valve lift switchover then still continues to occur, a warning signal can be output to the driver. In this way it is possible to prevent constant adjustments being made even though an error is present which cannot be rectified by means of an adjustment alone, but where, for example, it is necessary to visit a repair shop. In this case this can be communicated to the driver in good time.
[0040] According to the above-described method, the engine control unit can be connected to at least one sensor or to a plurality of sensors which detect a switchover error. Furthermore, as has already been described in the foregoing, the engine control unit is notified via a suitable interface if an external event occurs which can adversely affect the correct operation of the valve lift switchover function. For that purpose the engine control unit can have a corresponding arrangement by means of which it is determined whether a switchover error has been detected by the sensor or sensors or whether an external event has occurred. The valve lift switchover can then be blocked accordingly via the engine control unit, preferably for all operating states. Furthermore the engine control unit can activate the valve lift switchover only for at least one or for more than one noncritical operating state in order to perform a check of the valve lift switchover process. If the engine control unit establishes in so doing that the valve lift switchover is exhibiting abnormalities in the respective noncritical operating state, it can adapt or adjust parameters in a suitable manner in order to remove the abnormalities in the valve lift switchover in an appropriate manner, as described in detail hereintofore.
[0041] The advantage of the method according to various embodiments and of the device is essentially that following an external intervention (e.g. engine oil change, work on the valve lift switchover, etc.) or, as the case may be, following a single switching error, the system is afforded the opportunity to perform a self-test and if necessary to make adaptations or adjustments. The risk of a (serious) switching error is in this way reduced to a minimum. Furthermore driver and occupants are not adversely affected by any losses in comfort, since the check is performed in noncritical operating states.
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In a method and a device for examining a valve lift switching process in a motor vehicle the occurrence or the number of switching errors is reduced. The method has the steps of detecting whether a switching error and/or an external event occurs that may influence the mode of operation of the valve lift switching; blocking the valve lift switching if a switching error and/or an external event has occurred; activating and examining the valve lift switching during at least one uncritical operating condition; releasing the valve lift switching if the valve lift switching does not show any abnormalities during monitoring.
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[0001] This application is a Divisional Application of U.S. patent application Ser. No. 14/324,455 filed Jul. 7, 2014, now allowed, which is a Divisional Application of U.S. patent application Ser. No. 13/210,659 filed Aug. 16, 2011, now U.S. Pat. No. 8,887,660, which is a Divisional Application of U.S. patent application Ser. No. 12/947,012 filed Nov. 16, 2010, now U.S. Pat. No. 8,354,140, which is a Divisional Application of U.S. patent application Ser. No. 12/378,670 filed Feb. 18, 2009, now U.S. Pat. No. 8,206,783, which is a Divisional Application of U.S. patent application Ser. No. 11/246,825 filed Oct. 7, 2005, now U.S. Pat. No. 7,517,409, which is a Divisional Application of U.S. patent application Ser. No. 10/649,288 filed Aug. 27, 2003, now U.S. Pat. No. 7,160,574, which claims the benefit of priority to U.S. Provisional Patent Application 60/406,602 filed Aug. 28, 2002. The entire disclosure of each of the applications listed in this paragraph are incorporated herein by specific reference thereto.
FIELD OF INVENTION
[0002] This invention relates to piping repair and restoration, and in particular to methods, systems and apparatus for cleaning and providing barrier protective coatings to the interior walls of small metal and plastic type pipes such as drain lines, hot water lines, cold water lines, potable water lines, natural gas lines, HVAC piping systems, drain lines, and fire sprinkler system lines, and the like, that are used in multi-unit residential buildings, office buildings, commercial buildings, and single family homes, and the like.
BACKGROUND AND PRIOR ART
[0003] Large piping systems such as those used in commercial buildings, apartment buildings, condominiums, as well as homes and the like that have a broad base of users commonly develop problems with their pipes such as their water and plumbing pipes, and the like. These problems can include leaks caused by pipe corrosion and erosion, as well as blockage from mineral deposits that develop over time where materials build up directly inside the pipes. Presently when a failure in a piping system occurs the repair method may involve a number of applications. Those repair applications may involve a specific repair to the area of failure such as replacing that section of pipe or the use of a clamping devise and a gasket. In some cases the complete piping system of the building may need to be replaced.
[0004] In the case of pipes where the water flow has been impeded by rust build up or by a deposit build up such as calcium and other minerals, various methods for the removal of the rust or other build up have been used. However the damage caused by the rust or from other deposits to the pipe wall cannot be repaired unless the pipe is replaced.
[0005] Traditional techniques to correct for the corrosion, leakage and blockage problems have included replacing some or all of a building's pipes. In addition to the large expense for the cost of the new pipes, additional problems with replacing the pipes include the immense labor and construction costs that must be incurred for these projects.
[0006] Most piping systems are located behind finished walls or ceilings, under floors, in concrete or underground. From a practical viewpoint simply getting to the problem area of the pipe to make the repair can create the largest problem. Getting to the pipe for making repairs can require tearing up the building, cutting concrete and/or having to dig holes through floors, the foundation or the ground. These labor intensive repair projects can include substantial demolition of a buildings walls and floors to access the existing piping systems. For example, tearing out the interior walls to access the pipes is an expected result of the demolition.
[0007] Once the walls and floors have been opened, then the old pipes are usually pulled out and thrown out as scrap, which is then followed by replacement with new pipes. These prior techniques do little if nothing to reuse, refix, or recycle the old pipes.
[0008] In addition, there are usually substantial costs for removing the debris and old pipes from the worksite. With these projects both the cost of new pipes and the additional labor to install these pipes are required expenditures. Further, there are additional added costs for the materials and labor to replumb these new pipes along with the necessary wall and floor repairs that must be made to clean up for the demolition effects. For example, getting at and fixing a pipe behind drywall is not completing the repair project. The drywall must also be repaired, and just the drywall type repairs can be extremely costly. Additional expenses related to the repair or replacement of an existing piping system will vary depending primarily on the location of the pipe, the building finishes surrounding the pipe and the presence of hazardous materials such as asbestos encapsulating the pipe. Furthermore, these prior known techniques for making piping repair take considerable amounts of time that can include many months or more to be completed which results in lost revenue from tenants and occupants of commercial type buildings since tenants cannot use the buildings until these projects are completed.
[0009] Finally, the current pipe repair techniques are usually only temporary. Even after encountering the cost to repair the pipe, the cost and inconvenience of tearing up walls or grounds and if a revenue property the lost revenue associated with the repair or replacement, the new pipe will still be subject to the corrosive effects of fluids such as water that passes through the pipes.
[0010] Over the years many attempts have been proposed for cleaning water type pipes with chemical cleaning solutions. See for example, U.S. Pat. No. 5,045,352 to Mueller; U.S. Pat. No. 5,800,629 to Ludwig et al.; U.S. Pat. No. 5,915,395 to Smith; and U.S. Pat. No. 6,345,632 to Ludwig et al. However, all of these systems require the use of chemical solutions such as liquid acids, chlorine, and the like, that must be run through the pipes as a prerequisite prior to any coating of the pipes. The National Sanitation Foundation (NSF) specifically does not allow the use of any chemical agent solutions for use with cleaning potable water piping systems. Thus, these systems cannot be legally used in the United States for cleaning out water piping systems.
[0011] Other systems have been proposed that use dry particulate materials as a cleaning agent that is sprayed from mobile devices that travel through or around the pipes. See U.S. Pat. No. 4,314,427 to Stolz; and U.S. Pat. No. 5,085,016 to Rose. However, these traveling devices require large diameter pipes to be operational and cannot be used inside of pipes that are less than approximately 6 inches in diameter, and would not be able to travel around narrow bends. Thus, these devices cannot be used in small diameter pipes found in potable water piping systems that also have sharp and narrow bends.
[0012] The proposed systems and devices referenced above generally require sectioning a small pipe length for cleaning and coating type applications, or limiting the application to generally straight elongated pipe lengths. For large building such as multistory applications, the time and cost to section off various piping sections would be cost prohibitive. None of the prior art is known to be able to service an entire building's water type piping system at one time in one complete operation.
[0013] Thus, the need exists for solutions to the above problems with fixing existing piping systems in buildings.
SUMMARY OF THE INVENTION
[0014] A primary objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes in buildings without having to physically remove and replace the pipes.
[0015] A secondary objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes by initially cleaning the interior walls of the pipes.
[0016] A third objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes by applying a corrosion protection barrier coating to the interior walls of the pipes.
[0017] A fourth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes in buildings in a cost effective and efficient manner.
[0018] A fifth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes which is applicable to small diameter piping systems from approximately ⅜″ to approximately 6″ in piping systems made of various materials such as galvanized steel, black steel, lead, brass, copper or other materials such as composites including plastics, as an alternative to pipe replacement.
[0019] A sixth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes which is applied to pipes, “in place” or in situ minimizing the need for opening up walls, ceilings, or grounds.
[0020] A seventh objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes which minimizes the disturbance of asbestos lined piping or walls/ceilings that can also contain lead based paint or other harmful materials.
[0021] An eighth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where once the existing piping system is restored with a durable epoxy barrier coating the common effects of corrosion from water passing through the pipes will be delayed if not stopped entirely.
[0022] A ninth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes to clean out blockage where once the existing piping system is restored, users will experience an increase in the flow of water, which reduces the energy cost to transport the water. Additionally, the barrier epoxy coating being applied to the interior walls of the pipes can create enhanced hydraulic capabilities again giving greater flow with reduced energy costs.
[0023] A tenth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where customers benefit from the savings in time associated with the restoration of an existing piping system.
[0024] An eleventh objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where customers benefit from the economical savings associated with the restoration of an existing piping system, since walls, ceilings floors, and/or grounds do not always need to be broken and/or cut through.
[0025] A twelfth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where income producing properties experience savings by remaining commercially usable, and any operational interference and interruption of income-producing activities is minimized.
[0026] A thirteenth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where health benefits had previously accrued, as the water to metal contact will be stopped by a barrier coating thereby preventing the leaching of metallic and potentially other harmful products from the pipe into the water supply such as but not limited to lead from solder joints and from lead pipes, and any excess leaching of copper, iron and lead.
[0027] A fourteenth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where the pipes are being restored in-place thus causing less demand for new metallic pipes, which is a non-renewable resource.
[0028] A fifteenth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes using a less intrusive method of repair where there is less building waste and a reduced demand on expensive landfills.
[0029] A sixteenth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where the process uses specially filtered air that reduces possible impurities from entering the piping system during the process.
[0030] A seventeenth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where the equipment package is able to function safely, cleanly, and efficiently in high customer traffic areas.
[0031] An eighteenth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where the equipment components are mobile and maneuverable inside buildings and within the parameters typically found in single-family homes, multi unit residential buildings and various commercial buildings.
[0032] A nineteenth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where the equipment components can operate quietly, within the strictest of noise requirements such as approximately seventy four decibels and below when measured at a distance of approximately several feet away.
[0033] A twentieth objective of the invention is to provide methods, systems and devices for repairing interior walls of pipe where the barrier coating material for application in a variety of piping environments, and operating parameters such as but not limited to a wide temperature range, at a wide variety of airflows and air pressures, and the like.
[0034] A twenty first objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where the barrier coating material and the process is functionally able to deliver turnaround of restored piping systems to service within approximately twenty four hours or less or no more than approximately ninety six hours for large projects.
[0035] A twenty second objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where the barrier coating material is designed to operate safely under NSF(National Sanitation Foundation) Standard 61 criteria in domestic water systems, with adhesion characteristics within piping systems in excess of approximately 400 PSI.
[0036] A twenty third objective of the invention is to provide methods, systems and devices for repairing interior walls of pipes where the barrier coating material is designed as a long-term, long-lasting, durable solution to pipe corrosion, pipe erosion, pinhole leak and related water damage to piping systems where the barrier coating extends the life of the existing piping system.
[0037] A twenty fourth objective of the invention is to provide methods, systems and devices for both cleaning and coating interiors of pipes having diameters of up to approximately 6 inches using dry particulates, such as sand and grit, prior to coating the interior pipe walls.
[0038] A twenty fifth objective of the invention is to provide methods, systems and devices for both cleaning and coating interiors of pipes having diameters of up to approximately 6 inches in plural story buildings, without having to section off small sections of piping for cleaning and coating applications.
[0039] A twenty sixth objective of the invention is to provide methods, systems and devices for cleaning the interiors of an entire piping system in a building in a single pass run operation.
[0040] A twenty seventh objective of the invention is to provide methods, systems and devices for barrier coating the interiors of an entire piping system in a building in a single pass run operation.
[0041] The novel method and system of pipe restoration prepares and protects small diameter piping systems such as those within the diameter range of approximately ⅜ of an inch to approximately six inches and can include straight and bent sections of piping from the effects of water corrosion, erosion and electrolysis, thus extending the life of small diameter piping systems. The barrier coating used as part of the novel process method and system, can be used in pipes servicing potable water systems, meets the criteria established by the National Sanitation Foundation (NSF) for products that come into contact with potable water. The epoxy material also meets the applicable physical criteria established by the American Water Works Association as a barrier coating. Application within buildings ranges from single-family homes to smaller walk-up style apartments to multi-floor concrete high-rise hotel/resort facilities and office towers, as well as high-rise apartment and condominium buildings and schools. The novel method process and system allows for barrier coating of potable water lines, natural gas lines, HVAC piping systems, hot water lines, cold water lines, drain lines, and fire sprinkler systems.
[0042] The novel method of application of an epoxy barrier coating is applied to pipes right within the walls eliminating the traditional destructive nature associated with a re-piping job. Typically 1 riser system or section of pipe can be isolated at a time and the restoration of the riser system or section of pipe can be completed in less than one to four days (depending upon the building size and type of application) with water restored within approximately 24 to approximately 96 hours. For hotel and motel operators that means not having to take rooms off line for extended periods of time. Too, for most applications, there are no walls to cut, no large piles of waste, no dust and virtually no lost room revenue. Entire building piping systems can be cleaned within one run through pass of using the invention. Likewise, an entire building piping system can be coated within one single pass operation as well.
[0043] Once applied, the epoxy coating creates a barrier coating on the interior of the pipe. The application process and the properties of the epoxy coating ensure the interior of the piping system is fully coated. Epoxy coatings are characterized by their durability, strength, adhesion and chemical resistance, making them an ideal product for their application as a barrier coating on the inside of small diameter piping systems.
[0044] The novel barrier coating provides protection and extended life to an existing piping system that has been affected by erosion corrosion caused from internal burrs, improper soldering, excessive turns, and excessive water velocity in the piping system, electrolysis and “wear” on the pipe walls created by suspended solids. The epoxy barrier coating will create an approximately 4 mil or greater covering to the inside of the piping system.
[0045] There are primarily 3 types of metallic piping systems that are commonly used in the plumbing industry—copper, steel and cast iron. New steel pipes are treated with various forms of barrier coatings to prevent or slow the effects of corrosion. The most common barrier coating used on steel pipe is the application of a zinc based barrier coat commonly called galvanizing. New copper pipe has no barrier coating protection and for years was thought to be corrosion resistant offering a lifetime trouble free use as a piping system.
[0046] Under certain circumstances that involved a combination of factors of which the chemistry of water and installation practices a natural occurring barrier coating would form on the inside of copper pipes which would act as a barrier coating, protecting the copper piping system against the effects of corrosion from the water.
[0047] In recent history, due to changes in the way drinking water is being treated and changes in installation practices, the natural occurring barrier coating on the inside of copper pipe is not being formed or if it was formed is now being washed away. In either case without an adequate natural occurring barrier coating, the copper pipe is exposed to the effects of corrosion/erosion, which can result in premature aging and failure of the piping system.
[0048] With galvanized pipe the zinc coating wears away leaving the pipe exposed to the effects of the corrosive activity of the water. This results in the pipe rusting and eventually failing.
[0049] The invention can also be used with piping systems having plastic pipes, PVC pipes, composite material, and the like.
[0050] The novel method and system of corrosion control by the application of an epoxy barrier coating to new or existing piping systems is a preventative corrosion control method that can be applied to existing piping systems in-place.
[0051] The invention includes novel methods and equipment for providing barrier coating corrosion control for the interior walls of small diameter piping systems. The novel process method and system of corrosion control includes at least three basic steps: Air Drying a piping system to be serviced; profiling the piping system using an abrasive cleaning agent; and applying the barrier coating to selected coating thickness layers inside the pipes. The novel invention can also include two additional preliminary steps of: diagnosing problems with the piping system to be serviced, and planning and setting up the barrier coating project onsite. Finally, the novel invention can include a final end step of evaluating the system after applying the barrier coating and re-assembling the piping system.
[0052] Further objects and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments which are illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0053] FIG. 1 shows the general six steps that is an overview for applying the barrier coating.
[0054] FIGS. 2A, 2B, 2C and 2D shows a detailed process flowchart using the steps of FIG. 1 for providing the barrier coating.
[0055] FIG. 3 shows a side view of a multi-story story building using the novel barrier coating corrosion control method and system of the invention.
[0056] FIG. 4 shows a side view of the novel exhaust air diffuser used in the barrier coating control system in FIG. 3 .
[0057] FIG. 5A shows a perspective view of the novel portable air distribution manifold used in the barrier coating control system in FIG. 3 .
[0058] FIG. 5B shows a side view of the novel Pressure Generator System (Sander) 500 used in the barrier coating control system of FIG. 3 .
[0059] FIG. 5C is an enlarged view of the front control panel for use with the pressure generator system 500 of FIG. 5B .
[0060] FIG. 6A shows a side view of the novel Abrasive Reclaim Separator Module (Pre-Filter) used in the barrier coating control system of FIG. 3 .
[0061] FIG. 6B shows an end view of the novel Abrasive Reclaim Separator Module (Pre-Filter) used in the barrier coating control system of FIG. 3 .
[0062] FIG. 7A shows a side view of the novel Dust Collector System 700 (Filter) used in the barrier coating control system of FIG. 3 .
[0063] FIG. 7B shows an enlarged side cross-sectional view of the mounted Cartridge Filters used in the Dust Collector System of FIG. 7A .
[0064] FIG. 8A shows a perspective view of the novel Portable Epoxy Metering and Dispensing Unit 800 (Epoxy Mixer) used in the barrier coating control system of FIG. 3 .
[0065] FIG. 8B shows another perspective view of the novel Portable Epoxy Metering and Dispensing Unit 800 (Epoxy Mixer) used in the barrier coating control system of FIG. 3 .
[0066] FIG. 8C shows an enlarged view of the foot dispenser activator a part of the novel Portable Epoxy Metering and Dispensing Unit 800 (Epoxy Mixer) used in the barrier coating control system of FIG. 3 .
[0067] FIG. 8D is an enlarged view of the mixing tubes and mixing head of FIG. 8B
[0068] FIG. 9 shows a side view of the novel Main Air Header and Distributor 200 (Header) used in the barrier coating control system of FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0069] Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its application to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
[0070] FIG. 1 shows the general six steps for a project overview for applying the barrier coating to an existing piping system, which include step one, 10 program diagnosis, step two, 20 project planning, step three, 30 drying piping system, step four 40 , profiling the piping system, step five, 50 barrier coating interior walls of the pipes in the piping system, and final step six 60 evaluation and return to operation of the piping system.
Step One—Problem Diagnosis 10
[0071] For step one, 10 , several steps can be done to diagnose the problem with a piping system in a building, and can include:
(a) Interview onsite engineering staff, property mangers, owners or other property representatives as to the nature of the current problem with the piping system. (b) Evaluation of local and on-site water chemistry being used in the piping system for hardness and aggressive qualities. (c) Engineering evaluation, if necessary, to determine extent of present damage to the wall thickness of the piping and overall integrity of the piping system. (d) Additional on-site testing of piping system, if necessary, identifying leaks or the nature or extent of leaking. (e) Corrosion control proposal development for client, including options for pipe and fitting replacement where necessary. After completion of step one, 10 , the project planning and setup step 20 can be started.
Step Two—Project Planning and Setup 20
[0078] For step two, 20 , several steps can be followed for planning and setup for restoring the integrity of the piping system in a building, and can include:
(a) Complete contract development with client, after the diagnosis contract has started. (b) Commence project planning with site analysis crew, project management team, and on-site engineering/maintenance staff. (c) Plan delivery of the equipment and supplies to the worksite. (d) Complete equipment and supply delivery to worksite. (e) Commence and complete mechanical isolation of the piping system. (f) Commence and complete set up of hosing and equipment.
Step Three—Air Drying—Step 1 Method of Corrosion Control 30
[0085] For step three, 30 , the piping system to be prepared for the coating by drying the existing pipes, and can include:
(a) Piping systems are mapped. (b) Isolations of riser systems or pipe sections are prepared and completed. (c) The isolated piping system to receive the barrier coating is adapted to be connected to the barrier coating equipment. (d) The isolated riser system is drained of water. (e) Using moisture and oil free, hot compressed air, a flushing sequence is completed on the riser system to assure water is removed. (f) Riser system is then dried with heated, moisture and oil free compressed air. (g) Length of drying sequence is determined by pipe type, diameter, length complexity, location and degree of corrosion contained within the piping system, if any.
[0093] (h) Inspections are completed to assure a dry piping system ready for the barrier coating.
Step Four—Piping System Profiling—Step 2 of Method of Corrosion Control 40
[0094] For step four, 40 , the piping system is to be profiled, and can include:
(a) Dried pipes can be profiled using an abrasive agent in varying quantities and types. The abrasive medium can be introduced into the piping system by the use of the moisture and oil free heated compressed air using varying quantities of air and varying air pressures. The amount of the abrading agent is controlled by the use of a pressure generator. (b) The abraded pipe, when viewed without magnification, must be generally free of all visible oil, grease, dirt, mill scale, and rust. Generally, evenly dispersed, very light shadows, streaks, and discolorations caused by stains of mill scale, rust and old coatings may remain on no more than approximately 33 percent of the surface.
[0097] Also, slight residues of rust and old coatings may be left in the craters of pits if the original surface is pitted.
(c) Pipe profiling is completed to ready the pipe for the application of the barrier coating material. (d) Visual inspections can be made at connection points and other random access areas of the piping system to assure proper cleaning and profiling standards are achieved. (e) An air flushing sequence is completed to the riser system to remove any residuals left in the piping system from the profiling stage.
Step Five—Corrosion Control Epoxy Sealing and Protection of the Piping—Step 3 of the Method of Corrosion Control 50
[0101] For step five, 50 , the piping system is to barrier coated and can include:
(a) Piping system can be heated with hot, pre-filtered, moisture and oil free compressed air to an appropriate standard for an epoxy coating application. (b) Piping system can be checked for leaks. (c) Corrosion control barrier coating material can be prepared and metered to manufacturer's specifications using a proportionator. (d) Corrosion control barrier coating material can be injected into the piping system using hot, pre-filtered, moisture and oil free compressed air at temperatures, air volume and pressure levels to distribute the epoxy barrier coating throughout the pipe segment, in sufficient amounts to eliminate the water to pipe contact in order to create an epoxy barrier coating on the inside of the pipe. (e) The epoxy barrier coating can be applied to achieve coating of approximately 4 mils and greater. (f) Once the epoxy barrier coating is injected warm, pre-filtered, moisture and oil free compressed air can be applied over the internal surface of the pipe to achieve the initial set of the epoxy barrier coating.
[0108] (g) Confirm that all valves and pipe segments support appropriate air flow indicating clear passage of the air through the pipe i.e.: no areas of blockage. Allow the barrier coating to cure to manufacturer's standards.
Step Six—System Evaluation and Re-Assembly 60
[0109] The final step six, 60 allows for restoring the piping system to operation and can include:
(a) Remove all process application fittings. (b) Examine pipe segments to assure appropriate coating standards. (c) Re-confirm that all valves and pipe segments support appropriate air flow. (d) Install original valves, fittings/fixtures, or any other fittings/fixtures as specified by building owner representative. (e) Reconnect water system, and water supply. (f) Complete system checks, testing and evaluation of the integrity of the piping system. (g) Complete a water flush of system, according to manufacturer's specifications. (h) Evaluate water flow and quality. (i) Document riser schedule, and complete pipe labeling.
[0119] FIGS. 2A, 2B, 2C and 2D show a detailed process flowchart using the steps of FIG. 1 for providing the barrier coating. These flow chart figures show a preferred method of applying a novel barrier coating corrosion control for the interior of small diameter piping systems following a specific breakdown of a preferred application of the invention.
[0120] FIG. 3 shows a side view of a ten story building setup for using the novel method and system of the invention. Components in FIG. 3 will now be identified as follows:
[0000]
IDENTIFIER
EQUIPMENT
100
395, 850, 1100, 1600 CFM Compressors Outfitted with
Aftercooler, Water separator, Fine Filter and Reheater
200
Main Air Header and Distributor (Main Header)
300
Exhaust Air Diffuser (Muffler)
400
Portable Air Distribution Manifold (Floor Header)
500
Pressure Generator System (Sander)
600
Reclaim Separator Module (Pre-Filter)
700
Dust Collector System (Filter)
800
Portable Epoxy Metering and Dispensing Unit
(Epoxy Mixer)
900
Epoxy Barrier Coating
[0121] Referring to FIG. 3 , components 100 - 800 can be located and used at different locations in a ten story building. The invention allows for an entire building piping system to be cleaned in one single pass through run without having to dismantle either the entire or multiple sections of the piping system. The piping system can include pipes having diameters of approximately ⅜ of an inch up to approximately 6 inches in diameter with the piping including bends up to approximately ninety degrees or more throughout the building. The invention allows for an entire building piping system to have the interior surfaces of the pipes coated in one single pass through run without having to dismantle either the entire or multiple parts of the piping system. Each of the components will now be defined.
100 Air Compressor
[0122] The air compressors 100 can provide filtered and heated compressed air. The filtered and heated compressed air employed in various quantities is used, to dry the interior of the piping system, as the propellant to drive the abrasive material used in cleaning of the piping system and is used as the propellant in the application of the epoxy barrier coating and the drying of the epoxy barrier coating once it has been applied. The compressors 100 also provide compressed air used to propel ancillary air driven equipment.
200 Main Air Header and Distributor
[0123] An off the shelf main header and distributor 200 shown in FIGS. 3 and 9 can be one Manufactured By: Media Blast & Abrasives, Inc. 591 W. Apollo Street Brea, Calif. 92821 The components of the main header and distributor of FIG. 9 are labeled as follows.
Description of Main Header Equipment Describing Each Component:
[0000]
12 & 14 Gauge Steel Construction
Approximate Dimensions: 28″ w×27″ l×53″ h
Ford Grabber Blue Powder-coating
Air Pressure Gauge 205
Regulator Adjustment 210
Air Pressure Regulator 215
Moisture Bleeder Valve 220
2 2″ NPT Inlet With Full Port Ball Valve 225
14—1″ Side-Mounted Ball Valves—Regulated Air 230
4—1″ Top Mounted Ball Valves—Unregulated Air 235
1—2″ Top Mounted full port Ball Valve—Unregulated Air 240
1-2″ Top Mounted Full Port Ball Valve—Regulated Air 245
1.9 Cubic Feet Pressure Pot 250
Insulated Cabinet 255
Two Inflatable Tires 260
Push/Pull Handles 265
[0140] Referring to FIGS. 3 and 9 , the Main Header 200 provides safe air management capability from the air compressor for both regulated and unregulated air distribution (or any combination thereof) to the various other equipment components and to both the piping system risers and fixture outlets for a range of piping configurations from a single family home to a multi-story building. The air enters through the 2″ NPT inlet, 225 to service the pressure vessel. The main header 200 can manage air capacities ranging to approximately 1100 CFM and approximately 125 psi.
[0141] There are many novel parts and benefits with the Main Header and Distributor 200 . The distributor is portable and is easy to move and maneuver in tight working environments. Regulator Adjustment 210 can easily and quickly manage air capacities ranging to approximately 1600 CFM and approximately 200 psi, and vary the operating airflows to each of the other ancillary equipment associated with the invention. The Air Pressure Regulator 210 and the Method of Distributing the air allows both regulated and unregulated air management from the same equipment in a user-friendly, functional manner. The approximately 1″ Valving 230 , 235 , 245 allows accommodation for both approximately 1″ hosing and with adapters, and hose sizes of less than approximately 1″″ can be used to meet a wide variety of air demand needs on a job site. The insulated cabinet 255 , surrounding air works dampens noise associated with the movement of the compressed air. The insulated cabinet 255 , helps retain heat of the pre-dried and heated compressed air, the pre-dried and heated compressed air being an integral part of the invention. The insulated cabinet 255 , helps reduce moisture in the pressure vessel and air supply passing through it. Finally, the valving of the pressure vessel allows for delivery (separate or simultaneous) of regulated air to the side mounted air outlet valves 230 , the top mounted regulated air outlet valves 245 , as well as the top mounted unregulated air outlet valves 235 and 240 .
[0142] FIG. 4 shows a side view of the novel exhaust air diffuser 300 used in the bather coating control system in FIG. 3 .
300 EXHAUST AIR DIFFUSER (MUFFLER)
[0143] Referring to FIGS. 3 and 4 , an exhaust air diffuser and muffler 300 that can be used with the invention can be one Manufactured By: Media Blast & Abrasives, Inc. 591 W. Apollo Street, Brea, Calif. 92821.
[0000] Description of Muffler 300 components:
12 & 14 Gauge Steel Construction Approximate Dimensions: 34″ w×46″ l×76″ h Ford Grabber Blue Powder-coating Vented Access Panels on Both Sides of Unit 305 Vented End Panels 310 Dust Drawer with Removable Pan 315 Canvas Dust Bag Diffusers 320 2″ NPT Inlet 325 4″×8″ Expansion Chamber 330 Overhead Plenum 335 Two Swivel Casters 340 Two Locking Casters 350 Push/Pull Handles 360
[0157] Referring to FIGS. 3 and 4 , the Air Diffuser/Muffler 300 allows the safe, wholesale dumping of unregulated or regulated air from the compressor off of the Main Header 200 through the approximately 2″ NPT inlet, into the expansion chamber and canvas dust bag diffusers for the purpose of controlling the air temperature in the piping system during the drying phase, the pipe warming phase, the epoxy application phase and the initial curing phase of the epoxy barrier coating material after it is injected into the piping system. The Air diffuser 300 can eliminate the need to operate the air filter 600 during various stages of the process, promoting energy efficiency as the filter 600 is an air assisted and electrically powered piece of invention.
[0158] There are many novel parts and benefits to the Exhaust air diffuser 300 . The diffuser's portability allows for easy to move and maneuver in tight working environments. Vented access panels 305 allow for safe and even distribution of the air upon venting, prevents the build up of backpressure of the venting air and reduces the noise of the venting air. A Dust Drawer with Removable Pan 315 allows for easy clean out of the expansion chamber. A Canvas Dust Bag Diffuser 320 assures quiet, customer friendly discharge of air. An approximately 2″ NPT Inlet 325 allows full range of air diffusion from approximately 1″ to approximately 2″ discharge hoses. A 4″×8″ Expansion Chamber 330 allows for rapid dispersing of the air upon entering the Air Diffuser 300 . The expansion chamber 330 permits the compressed air that enters the diffuser 300 to expand allowing for a more efficient and safe passage to exit, which reduces the noise of the air upon departure and helps reduce the build up of backpressure of the exiting air from the piping system. The Air Diffuser 300 promotes the rapid unrestricted movement of the compressed air in volumes greater than approximately 1100 CFM and can operate with air pressures greater than approximately 120 PSI. When used in conjunction with the heated, pre-filtered compressed air of the compressor 100 , the use of the Air Diffuser 300 creates a more efficient movement of the heated air, which results in a cost savings by drying the pipes faster, drying the epoxy faster, which in turn saves manpower, fuel and reduces the operational time of the compressor 100 .
[0159] FIG. 5A shows a preferred portable air distribution manifold 400 that can be used in the exemplary setup shown in FIG. 3
400 Portable Air Distribution Manifold
[0160] Referring to FIGS. 3 and 5A , an on off-the-shelf manifold 400 can be one Manufactured By: M & H Machinery 45790 Airport Road, Chilliwack, BC, Canada Description of Manifold 400 Components:
Main Air Cylinder 2½″×12″ Schedule 40 Steel Construction Ford Grabber Blue Paint Finishes 4-1″ Welded Nipples Placed at a 45° Angle to the Base Cylinder; Male Threaded 410 1″ NPT Female Threaded Portals at Each End of Cylinder 420 2 Metal Legs for Support and Elevation of Manifold 430 Pressure Rated Vessels to 125 PSI or Greater 440 Attached for Air Control, 1″ Full Port Ball Valves NPT; Female Threaded 450 All Hose End Receptors are NPT 1″; Female Threaded 460
[0169] As part of the general air distribution system set up, the floor manifolds 400 can be pressure rated vessels designed to evenly and quietly distribute the compressed air to at least 5 other points of connection, typically being the connections to the piping system. Airflow from each connection at the manifold is controlled by the use of individual full port ball valves.
[0170] There are many novel parts and benefits to the Air Manifold 400 . The portability of manifold 400 allows for easy to move and maneuver in tight working environments. The elevated legs 430 provide a stable base for unit 400 as well as keep the hose end connections off the floor with sufficient clearance to permit the operator ease of access when having to make the hose end connections. The threaded nipples 410 placed at approximately 45° angle allow for a more efficient use of space and less restriction and constriction of the airline hoses they are attached to. Multiple manifolds 400 can be attached to accommodate more than 5 outlets. The manifolds can be modular and can be used as 1 unit or can be attached to other units and used as more than 1.
[0171] FIG. 5B shows a perspective view of the novel pressure generator sander system 500 used in the barrier coating control system in FIG. 3 . FIG. 5C shows the front control panel of the sander system.
500 Pressure Generator System-Sander
[0172] Referring to FIGS. 3, 5B and 5C , a pressure generator sander 500 that can be used with the invention can be one Manufactured By: Media Blast & Abrasives, Inc.591 W. Apollo Street Brea, Calif. 92821.
Description of Sander 500 Components:
[0000]
12 & 14 Gauge Steel Construction
Approximate Dimensions: 20″ w×24″ l×42″ h
Ford Grabber Blue Powder-coating
1-1″ NPT Inlets 505
1—1″ NPT Outlet 510
3—Air Breather Mufflers 515
Pop-up Valve gasket 520
Pop-up Valve 525
Hand Port Gasket 530
Pressure Pot with Hand Port and Hopper 535
Filler Lid with Latches 540
Mixing Valve 545
Remote Regulator 550
Process Valve 555
Toggle Switch 560
Air Pressure Gauge 565
Regulator Adjustment 570
Pulse Button 580
Wheel Assembly 585
2—Inflatable Tires 590
[0193] The pressure generating sander system 500 can provide easy loading and controlled dispensing of a wide variety of abrasive medium in amounts up to approximately 1.3 US gallons at a time. The pressure generator sander can include operational controls that allow the operator to easily control the amount of air pressure and control the quantity of the abrasive medium to be dispersed in a single or multiple application. The abrasive medium can be controlled in quantity and type and is introduced into a moving air steam that is connected to a pipe or piping systems that are to be sand blasted clean by the abrasive medium. The sand can be introduced by the pressure generator sander system 500 by being connected to and be located outside of the piping system depicted in FIG. 3 . The novel application of the sander system 500 allows for cleaning small pipes having diameters of approximately ⅜″ up to approximately 6″.
[0194] Table 1 shows a list of preferred dry particulate materials with their hardness ratings and grain shapes that can be used with the sand generator 500 , and Table 2 shows a list of preferred dry particulate particle sieve sizes that can be used with the invention.
[0000]
TABLE 1
PARTICULATES
Material
Hardness Rating
Grain Shape
Diamond
10
Cubical
Aluminium Oxide
9
Cubical
Silica
5
Rounded
Garnet
5
Rounded
Walnut shells
3
Cubical
[0000]
TABLE 2
PARTICULATE SIZE
SIEVE SIZE OPENING
U.S. Mesh
Inches
Microns
Millimeters
4
.187
4760
4.76
8
.0937
2380
2.38
16
.0469
1190
1.19
25
.0280
710
.71
45
.0138
350
.35
[0195] There are many novel parts and benefits to the use of the Pressure Generator Sander System 500 . The portability allows for easy to move and maneuver in tight working environments. The sander 500 is able to accept a wide variety of abrasive media in a wide variety of media size. Variable air pressure controls 570 in the sander 500 allows for management of air pressures up to approximately 125 PSI. A mixing Valve 545 adjustment allows for setting, controlling and dispensing a wide variety of abrasive media in limited and controlled quantities, allowing the operator precise control over the amount of abrasive medium that can be introduced into the air stream in a single or multiple application. The filler lid 540 , incorporated as part of the cabinet and the pressure pot allows the operator to load with ease, controlled amounts of the abrasive medium into the pressure pot 535 . The pulse button 580 can be utilized to deliver a single sized quantity of the abrasive material into the air stream or can be operated to deliver a constant stream of abrasive material in to the air stream. All operator controls and hose connections can be centralized for ease of operator use.
[0196] FIG. 6A shows a side view of the novel Abrasive Reclaim Separator Module (Pre-Filter) 600 used in the barrier coating control system of FIG. 3 . FIG. 6B shows an end view of the novel Abrasive Reclaim Separator Module (Pre-Filter) 600 used in the barrier coating control system of FIG. 3 .
600 Abrasive Reclaim Separator Module (Pre-Filter)
[0197] Referring to FIGS. 3, 6A and 6B , an off-the-shelf pre-filter that can be used with the invention can be one Manufactured By: Media Blast & Abrasives, Inc. 591 W. Apollo Street Brea, Calif. 92821
Description of Pre-Filter 600 Components:
[0000]
12 & 14 Gauge Steel Construction
Approximate Dimensions: 23″ w×22″ l×36″ h
Ford Grabber Blue Powder-coating
Dust Drawer with Removable Pan 610
2-2″ NPT Inlets 620
Approximate Dimensions: 13¼″ w×13¼″ 1×17″ h Cyclone Chamber/Separator 630
8″ Air and Dust Outlet with Flexible Duct to Air Filter 640
Two Inflatable Tires 650
Push/Pull Handle 660
[0207] During the pipe profiling stage, the Pre-Filter 600 allows the filtering of air and debris from the piping system for more than two systems at a time through the 2—approximately 2″ NPT inlets 620 . The cyclone chamber/separator 630 captures the abrasive material and large debris from the piping system, the by products of the pipe profiling process. The fine dust particles and air escape through the approximately 8″ air and dust outlet 640 at the top of the machine and are carried to the dust collection equipment 700 , which filters, from the exhausting air, fine particulates, that may not have been captured with the Pre-Filter 600 .
[0208] There are many novel parts and benefits to the Pre-Filter 600 . The pre-filter has portability and is easy to move and maneuver in tight working environments. The Dust Drawer with Removable Pan 610 allows for easy clean out of the abrasive media and debris from the pipe. The Cyclone Chamber/Separator 630 slows and traps the abrasive media and debris from the piping system and air stream, and prevents excess debris from entering into the filtration equipment. The 2—approximately 2″ NPT Inlet 620 allows a full range of air filtration from two separate riser or piping systems. Use of the approximately 8″ or greater flex tube 640 as an expansion chamber results in reducing the air pressure of the air as it leaves the pre-filter 600 and reduces the potential for back pressure of the air as it departs the pre-filter and enhances the operational performance of the air filter. When used in conjunction with the air filter 700 , the Pre-filter 600 provides a novel way of separating large debris from entering the final stage of the filtration process. By filtering out the large debris with the pre-filter 600 this promotes a great efficiency of filtration of fine particles in the final stages of filtration in the air filter 700 . The approximately 8″ air and dust outlet 640 to the air filter 700 from the pre-filter 600 permits the compressed air to expand, slowing it in velocity before it enters the air filter 700 , which enhances the operation of the air filter 700 . Process cost savings are gained by the use of the pre-filter 600 by reducing the impact of filtering out the large amounts of debris at the pre-filter stage prior to air entering the air filter 700 . This provides for greater operating efficiencies at the air filter 700 a reduction in energy usage and longer life and use of the actual fine air filters 760 used in the air filter 700 .
700 Dust Collection Filter
[0209] Referring to FIGS. 3, 7A and 7B , an off-the-shelf example if a filter 700 used with the invention can be one Manufactured By: Media Blast & Abrasives, Inc. 591 W. Apollo Street, Brea, Calif. 92821.
Description of Air Filter 700 Components:
[0000]
12 & 14 Gauge Steel Construction
Approximate Dimensions: 24″ w×32″1×65″ h
Ford Grabber Blue Powder-coating
Dust Drawer with Removable Pan and Tightening Knobs 705
1-¾ NPT Inlet 710
2.0 HP Baldor Motor, Volts 115/230 715
8″ Air and Dust Inlet with Flexible Duct to Pre-Filter 720
Ball Vibrator Muffler 725
2—Locking Wheels 730
2—Swivel and Locking Wheels 735
Pushbutton Switch 740
Mushroom Head Switch 745
Selector Switch 750
Tightening Knob 755
2—Corrugated Cartridge Filters, approximately 99.98% Efficient, Collecting 0.5
[0225] Micron Particles (based on SAE-J726 test) 760
Cartridge Mounting Rods 765 Cartridge Mounting Plates 770 Filter Tightening Knobs 775 Filter Ball Tightening Knobs 780 Sliding Air Control Exit Vent 785
[0231] During the pipe profiling stage, the filter or dust collector 700 is the final stage of the air filtration process. The dust collector 700 filters the passing air of fine dust and debris from the piping system after the contaminated air first passes through the pre-filter 600 (abrasive reclaim separator module). During the epoxy coating drying stage the filter 700 is used to draw air through the piping system, keeping a flow of air running over the epoxy and enhancing its drying characteristics. The filter 700 creates a vacuum in the piping system which is used as method of checking for airflow in the piping system, part of the ACE DuraFlo process. The dust collector 700 can be capable of filtering air in volumes up to approximately 1100 CFM.
[0232] There are many novel parts and benefits to the Air Filter 700 . The air filter has portability and is easy to move and maneuver in tight working environments. The Dust Drawer with Removable Pan 705 allows for easy clean out of the abrasive media and debris from the filtration chamber. The 8″ flexible duct 640 (from FIG. 6A permits the compressed air to expand and slow in velocity prior to entering the dust collector 700 , enhancing efficiency. The sliding air control exit vent 785 permits use of a lower amperage motor on start up. The reduced electrical draw enables the dust collector 700 to be used on common household electrical currents while still being able to maintain its capacity to filter up to approximately 1100 CFM of air. The air filter 700 keeps a flow of air running over the epoxy and enhancing its drying and curing characteristics. The dust collector 700 creates a vacuum in the piping system, which is used as method of checking for airflow in the piping system.
800 Portable Epoxy Metering and Dispensing Unit
[0233] Referring to FIGS. 3, 8A, 8B and 8C , a metering and dispensing unit 800 used with the invention can be one Manufactured by: Lily Corporation, 240 South Broadway, Aurora, Ill. 60505-4205.
Description of Metering and Dispensing Unit 800 Components:
[0000]
Aluminum Frame And Cabinet Construction
Approximate Dimensions: 48″ L×48″ H×22″ W
Blue and Black Anodized Finishes
Electrical Powered Space Heating Element and Thermostat 805
Temperature Gauge 810
1-3 Gallon Stainless Steel Pressure Pot for Resin Part A 815
1-3 Gallon Stainless Steel Pressure Pot for Catalyst Part B 820
Pressure Valve For Each Tank 825
Side Door Access Panel 830
Parts and Tool Drawer 835
Aluminum Removable Cover To Access Pressure Pots 840
Adjustable Cycle or Shot Counter 845
4 Wheels—Swivel and Locking 850
Coalescing Air Filter 855
Air Pressure Regulator and Gauge 860
Foot Dispenser Activator 865
Abort Switch 870
On/Off Control Switch 875
Compressed Air Driven Epoxy Meter and Pump Adjustable for Dispensing Up To 14.76 Oz of Mixed Epoxy Per Single Application. Multiple Applications Can Dispense Up To 75 Gallons of Epoxy Per Hour. 880
Threaded Epoxy Mixing Head To Accommodate Disposable Epoxy Mixing Tubes 887 and mixing head 885 .
Push/Pull Handle 890
Epoxy Carrying Tube Hanger 895
[0256] The Portable Epoxy Metering and Dispensing Unit 800 can store up to approximately 3 US gallons of each of A and B component of the two mix component epoxy, and can dispense single shots up to approximately 14.76 oz, in capacities up to approximately 75 US gallons per hour.
[0257] The unit 800 can be very mobile and can be used both indoors and outdoors, and it can operate using a 15 Amp 110 AC electrical service i.e.: regular household current and approximately 9 cubic feet (CFM) at 90 to 130 pounds per square inch. The unit 800 requires only a single operator.
[0258] The epoxy used with the unit 800 can be heated using this unit to its recommended temperature for application. The epoxy can be metered to control the amount of epoxy being dispensed.
[0259] There are many novel parts and benefits to the Epoxy Metering and Dispensing Unit 800 , which include portability and is easy to move and maneuver in tight working environments. The heated and insulted cabinet, all epoxy transit hoses, valves and pumps can be heated within the cabinet. The Top filling pressurized tanks 815 and 820 offers ease and access for refilling. Epoxy can be metered and dispensed accurately in single shot or multiple shots having the dispensing capacity up to approximately 14.76 ounces of material per shot, up to approximately 75 gallons per hour. The position of mixing head 885 , permits a single operator to fill the portable epoxy carrying tubes 887 in a single fast application. The drip tray permits any epoxy overspill at the time of filling to be contained in the drip tray, containing the spill and reducing cleanup. The epoxy carrying tube hanger 895 allows the operator to fill and temporarily store filled epoxy tubes, ready for easy distribution. The pump 880 and heater 805 combination allows for the epoxy to metered “on ratio” under a variety of conditions such as changes in the viscosity of the epoxy components which can differ due to temperature changes which effect the flow rates of the epoxy which can differ giving the operator an additional control on placement of the epoxy by changing temperature and flow rates. Unit 800 overall provides greater operator control of the characteristics of the epoxy in the process.
900 Epoxy Barrier Coating
[0260] Referring to FIGS. 3 and 8A, 8B and 8C , a preferred epoxy barrier coating that can be used with the invention can be one Manufactured by: CJH, Inc. 2211 Navy Drive, Stockton, Calif. 95206. The barrier coating product used in this process can be a 2-part thermo set resin with a base resin and a base-curing agent.
[0261] The preferred thermo set resin is mixed as a two-part epoxy that is used in the invention. When mixed and applied, it forms a durable barrier coating on pipe interior surfaces and other substrates. The barrier coating provides a barrier coating that protects those coated surfaces from the effects caused by the corrosive activities associated with the chemistry of water and other reactive materials on the metal and other substrates.
[0262] The epoxy barrier coating can be applied to create a protective barrier coating to pipes ranging in size approximately ⅜″ to approximately 6″ and greater. The barrier coating can be applied around bends intersections, elbows, t's, to pipes having different diameters and make up. The barrier coating can be applied to pipes in any position e.g.: vertical or horizontal, and can be applied as a protective coating to metal pipes used in fire sprinkler systems and natural gas systems. Up to approximately 4 mils thick coating layers can be formed on the interior walls of the pipes. The barrier coating protects the existing interior walls and can also stop leaks in existing pipes which have small openings and cracks, and the like, of up to approximately ⅜ th ″ in diameters in size.
[0263] Although the process of application described in this invention includes application of thermo set resins other types of thermo set resins can be used.
[0264] For example, other thermo set resins can be applied in the process, and can vary depending upon viscosity, conditions for application including temperature, diameter of pipe, length of pipe, type of material pipe comprised of, application conditions, potable and non potable water carrying pipes, and based on other conditions and parameters of the piping system being cleaned and coated by the invention.
[0265] Other thermo set type resins that can be used include but are not limited to and can be one of many that can be obtained by numerous suppliers such as but not including: Dow Chemical, Huntsmans Advances Material, formerly Ciba Giegy and Resolution Polymers, formerly Shell Chemical.
[0266] Although the novel invention can be applied to all types of metal pipes such as but not limited to copper pipes, steel pipes, galvanized pipes, and cast iron pipes, the invention can be applied to pipes made of other materials such as but not limited to plastics, PVC(polyvinyl chloride), composite materials, polybutidylene, and the like. Additionally, small cracks and holes in plastic type and metal pipes can also be fixed in place by the barrier coating.
[0267] Although the preferred applications for the invention are described with building piping systems, the invention can have other applications such as but not limited to include piping systems for swimming pools, underground pipes, in-slab piping systems, piping under driveways, various liquid transmission lines, tubes contained in heating and cooling units, tubing in radiators, radiant in floor heaters, chillers and heat exchange units, and the like.
[0268] While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.
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Methods and systems for providing cleaning and providing barrier coatings to interior wall surfaces of small diameter metal and composite piping systems in buildings. An entire piping system can be cleaned in one single pass by dry particulates forced by air throughout the building piping system by an external generator, and the entire piping system can be coated in one single pass by a machine connected exterior to the piping system. Small pipes can be protected by the effects of water corrosion, erosion and electrolysis, extending the life of piping systems such as copper, steel, lead, brass, cast iron piping and composite materials. Coatings can be applied to pipes having diameters of approximately ⅜″ up to approximately 6″ so that entire piping systems such as potable water lines, natural gas lines, HVAC piping systems, drain lines, and fire sprinkler systems in single-family homes to apartments to high-rise hotel/resort facilities and office towers, apartment and condominium buildings and schools, can be cleaned and coated to pipes within existing walls. The coating forms an approximately 4 mils or greater covering inside of pipes. Buildings can return to service within approximately 24 to approximately 96 hours.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present invention claims the benefit under 35 USC §119(e) of prior U.S. provisional patent application Ser. No. 60/448,459 to Rabipour et al., filed Feb. 21, 2003, incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to communications networks and, more particularly, to methods and apparatus for increasing the service quality and efficiency with which data is communicated between entities in such networks.
BACKGROUND OF THE INVENTION
[0003] According to most existing telecommunications standards, the transmission of speech information over a wireless interface takes the form of compressed speech parameters.
[0004] Upon receipt of compressed speech parameters at a base station in communication with a mobile unit, the speech parameters are processed by a codec (coder/decoder), which converts (expands) the speech parameters into speech samples, typically at a rate of 64 kilobits per second (kb/s) in order to provide compatibility with the public switched telephone network (PSTN). The speech samples at 64 kb/s are then transmitted over the PSTN towards the called party. The speech samples associated with a given call may share the same link as speech samples associated with other calls by virtue of time division multiplexing (TDM), which provides for fixed-duration time slots to be allotted to individual calls.
[0005] If the called party is connected directly to the PSTN, such as via a wireline connection, the speech samples having travelled through the network will simply be converted into audio form by a digital telephone unit at the called party site. Of course, the called party may also be a second mobile unit, in which case the speech samples will terminate at a second base station, where a second codec re-converts the speech samples back into compressed speech parameters for transmission to the second mobile unit via a wireless interface. The usage of a source decoder to expand speech parameters into a stream of speech samples, in combination with the use of a destination encoder for re-compression of these samples into a second set of compressed speech parameters, is referred to as operation of codecs in tandem, or “tandem operation”.
[0006] Those skilled in the art will appreciate that when both the called and calling parties are mobile units, the tandem operation described above introduces a degradation in service quality, as errors may be introduced by the decompression and re-compression operations performed by the source and destination codecs, respectively. Such error should in principle be avoidable, as neither codec operation is required by virtue of the second base station requiring the compressed speech parameters rather than the expanded speech samples. Thus, it is of interest to find a solution to the problem of service quality in call connections involving tandem codecs.
[0007] Two classes of solutions to the problem relating to the service quality in call connections involving tandem codecs have already been described and standardized, or are well in their way towards standardization. The earlier of the two methods, called Tandem-Free Operation (TFO), uses an in-band handshaking protocol to detect the presence of tandem codecs, and then proceeds to insert the compressed speech parameters within the 64 kb/s sample stream. This arrangement bypasses the requirement for decompression at the source codec and (re-)compression at the destination codec, which obviates the occurrence of errors at these two stages. As a result, a high quality of service can be achieved for a given end-to-end call between two mobile units. However, the standardized TFO approach provides no bandwidth advantage, as the full bandwidth ordinarily needed for the 64 kb/s sample stream is consumed for transmission of the compressed speech parameters.
[0008] A more recent approach, called Transcoder-Free Operation (TrFO), uses out-of-band signaling to detect call scenarios involving tandem codecs at call set-up time. Thereupon action is taken to put in place a direct end-to-end link to provide for a direct exchange of the compressed speech parameters without the involvement of network transcoders. However, while it provides for a savings and resource reduction compared to the standardized TFO approach, the TrFO implementation suffers from the disadvantage of added cost and complexity due to, for example, the requirement for out-of-band signaling.
[0009] For more information on the TFO and TrFO techniques, the reader is invited to refer to the following documents that are hereby incorporated by reference:
[0010] 3 rd generation partnership project, Technical specification group core network, Out of band transcoder control—Stage 2 (3GPP TS 23.153 V4.4.0 (2001-12));
[0011] 3 rd generation partnership project, Technical specification group core network, Bearer-independent circuit-switched core network, Stage 2 (3GPP TS 23.205 V4.4.0 (2002-03));
[0012] 3 rd generation partnership project, Technical specification group (TSG) RAN3, Transcoder free operation (3GPP TR 25.953 V4.0.0 (2001-03));
[0013] 3 rd generation partnership project, Technical specification group services and system aspects, Inband tandem free operation (TFO) of speech codecs, service description—Stage 3 (3GPP TS 28.062 V5.0.0 (2002-03));
[0014] It will thus be apparent that there is a need in the industry to provide a solution that is as robust and easy to implement, while also providing bandwidth and resource savings.
[0015] Moreover, the use of conventional codec-bypass schemes such as TFO has heretofore been limited to enhancing the quality of calls established between two suitably enabled base station units in a mobile-to-mobile call. When one party is not so enabled, e.g., a telephone connected to a common packet-switched network via a network gateway, the use of conventional codec-bypass techniques is not possible. It would therefore be an advantage to exploit the ability of one party's codec-bypass capabilities, even when the other party is not a suitably enabled base station unit.
[0016] In addition, the use of conventional codec-bypass schemes is often limited by the use of backhaul gateways in a network, even when both parties to a call are codec-bypass-enabled base station units. Such gateways compress speech samples into a different format prior to transmittal of the formatted speech samples over a network. Unfortunately, when codec-bypass information is carried within the bit structure of the speech samples, the compression effected by a backhaul gateway results in loss of the information and hence prevents advantageous usage of this facility. Hence, it would be beneficial to be able to allow tandem-free operation in circumstances where a backhaul gateway is used.
SUMMARY OF THE INVENTION
[0017] The present invention realizes that although an end-to-end codec-bypass connection along a given path between two endpoints may not be possible, it is nevertheless possible to achieve bandwidth savings by establishing a codec-bypass connection along only a portion of the path.
[0018] Therefore, according to a first broad aspect, the invention seeks to provide a communication apparatus, comprising a first interface for exchanging data with a first neighboring entity, a second interface for exchanging data with a second neighboring entity, a memory for storing codec information regarding the communication apparatus and a control entity operative to detect a first message from the first neighboring entity via the first interface, the first message being indicative of codec information regarding an originating entity. Responsive to detection of the first message, the control entity is operative to perform an assessment of compatibility between the codec information regarding the originating entity and the codec information regarding the communication apparatus. Responsive to the assessment of compatibility being positive, the control entity is operative to self-identify the communication apparatus as a candidate for terminally supporting a subsequent codec-bypass negotiation with the originating entity. Responsive to the assessment of compatibility being negative, the control entity is operative to self-identify the communication apparatus as a candidate for non-terminally supporting a subsequent codec-bypass negotiation with the originating entity.
[0019] According to a second broad aspect, the invention seeks to provide a method of establishing candidacy of a gateway as terminally or non-terminally supporting a codec-bypass negotiation with an originating entity in a communications network. The method comprises detecting a first message received from a first neighboring entity, the first message being indicative of codec information regarding the originating entity; assessing compatibility between the codec information regarding the originating entity and the codec information regarding the gateway; responsive to the assessment of compatibility being positive, self-identifying the gateway as a candidate for terminally supporting a subsequent codec-bypass negotiation with the originating entity; and, responsive to the assessment of compatibility being negative, self-identifying the gateway as a candidate for non-terminally supporting a subsequent codec-bypass negotiation with the originating entity.
[0020] The invention also seeks to provide, in accordance with a third broad aspect, computer-readable media tangibly embodying a program of instructions executable by a computer to perform the above method of establishing candidacy of a gateway as terminally or non-terminally supporting a codec-bypass negotiation with an originating entity in a communications network.
[0021] According to a fourth broad aspect, the present invention seeks to provide a method of establishing a codec-bypass connection between a first gateway and one of a plurality of in-path gateways located along a path from the first gateway to a second gateway. The method comprises identifying a target in-path gateway from among the plurality of in-path gateways, the target in-path gateway being the in-path gateway furthest along the path from the first gateway which is characterized by codec-bypass connection compatibility with the first gateway, and establishing a codec-bypass connection between the first gateway and the target in-path gateway.
[0022] The invention may also be summarized according to a fifth broad aspect as seeking to provide a method of establishing a codec-bypass connection along a path between a first gateway and a second gateway, the path comprising a plurality of in-path gateways. The method comprises identifying a first sub-path between the first gateway and a first target in-path gateway from among the plurality of in-path gateways, the first target in-path gateway being the in-path gateway furthest along the path from the first gateway which is characterized by codec-bypass connection compatibility with the first gateway. The method also comprises identifying a second sub-path between the second gateway and a second target in-path gateway from among the plurality of in-path gateways, the second target in-path gateway being the in-path gateway furthest along the path from the second gateway which is characterized by codec-bypass connection compatibility with the second gateway. The method further comprises determining the lengths of the first and second sub-paths and, if the first sub-path is longer than the second sub-path, establishing a codec-bypass connection between the first gateway and the first target gateway, otherwise if the second sub-path is longer than the first sub-path, establishing a codec-bypass connection between the second gateway and the second target gateway.
[0023] These and other aspects and features of the present invention will now become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In the accompanying drawings:
[0025] [0025]FIGS. 1A to 1 D shows various call scenarios to which embodiments of the present invention are applicable;
[0026] [0026]FIG. 2 is a message flow diagram illustrating various steps in establishing a codec-bypass connection in the scenario of FIG. 1A, in accordance with a specific embodiment of the present invention; and
[0027] FIGS. 3 to 8 show various alternative configurations to which embodiments of the present invention are applicable.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] In accordance with an embodiment of the present invention, arbitrary combinations of wireless/wireline gateways collaborate constructively to reduce bandwidth and delay, and to achieve higher voice quality by removing—to the extent possible—tandem codecs (or vocoders). The present description herein below describes a method to resolve the disposition of the gateways that could find themselves involved in an codec-bypass connection. The gateways being given consideration are those which modify the speech payload (e.g. transcoding between different codec formats, including G.711).
[0029] With reference to FIG. 1A, a connection (e.g., a telephone call) is established between two endpoints A, B in a network consisting of a plurality of communication apparatuses hereinafter referred to as gateways. The network in question may include a circuit-switched network (e.g., the public switched telephone network—PSTN), a packet network or a combination thereof. Each of the endpoints A, B of the call may be either of a mobile station (wireless) or a land-based unit (wireline).
[0030] Various types of gateways are traversed by the call as it travels along subsequent legs of a call from one endpoint to another. The following definitions of various types of gateways have been provided for purposes of clarity, but without any intent to limit or otherwise restrict the scope of the present invention.
[0031] In particular, a “TDM gateway” is defined as a gateway that connects a circuit-switched network to a packet network. A “packet gateway” is defined as a gateway that connects only to a packet network. An “endpoint gateway” (or “termination gateway”) is defined as a gateway located at an extreme end of the signal path. An example of an endpoint gateway is a UMTS gateway. In FIG. 1A, endpoint gateways include gateways A and B. Finally, an “in-path gateway” is defined as a gateway that is an intermediate node in the signal path (i.e. not an endpoint gateway). In FIG. 1A, in-path gateways include gateways 1, 2 and 3.
[0032] In general, a gateway comprises communications interfaces for communicating with neighbouring entities. In the case of an in-path gateway, the neighbouring entities are other gateways. Each gateway is configured to exchange signals in a variety of formats that are defined by a set of codecs with which the gateway is associated. Accordingly, each gateway is equipped with a memory element for storing codec information regarding the gateway in question. In the example of FIG. 1A, gateways A, 1 and 3 are associated with codec X, while gateway 2 is associated with codec Y and gateway B is associated with codec Z. It is noted that each gateway may be associated with more than one codec.
[0033] Once a call is established between the endpoints, the endpoint gateways attempt to establish a codec-bypass connection. This attempt is made through the exchange of codec-bypass negotiation messages during a codec-bypass negotiation. If the two endpoint gateways are associated with a common codec, then an end-to-end codec-bypass connection can indeed be established through codec-bypass negotiation (or “dialogue”). This provides significant quality enhancement.
[0034] When the two endpoint gateways are not associated with a common codec, then one may have recourse to a procedure whereby a codec-bypass connection is negotiated (“dialogued”) for only a portion of the path that joins the endpoint gateways. This procedure, which is described in greater detail herein below, results in bandwidth savings and quality enhancement compared with the case where an attempt at establishing end-to-end codec-bypass mode of operation would be altogether abandoned. In a specific embodiment, the gateways along the path joining the endpoint gateways negotiate a codec-bypass mode of operation connection for the longest possible portion of that path.
[0035] It is assumed, for the purposes of description, that the various in-path gateways along the path are at least minimally codec-bypass compliant, without necessarily being able to terminate a codec-bypass negotiation or connection. Specifically, depending on the particular codec used by a remote entity and on the particular phase of a codec-bypass negotiation, a gateway is assumed to be at least capable of acquiring a “passive” mode. A gateway in “passive” mode is capable of relaying codec-bypass negotiation messages from one leg to another leg of a call that it serves, but it does not terminate the negotiation, i.e., it only serves to “passively support” a codec-bypass negotiation. However, depending on the capabilities of the gateway, the gateway may also be able to acquire an “active” mode for the purposes of the codec-bypass negotiation. In “active” mode, the gateway is capable of terminally supporting (i.e., terminating) a codec-bypass negotiation on at least one leg of a call that it serves. Thus, the gateway thus operates differently in passive mode and in active mode, assuming that the active mode can be acquired for a given codec-bypass negotiation.
[0036] [0036]FIG. 2 illustrates a non-limitative example of operation of the present invention with respect to the specific scenario in FIG. 1A. The following describes the coordination of the in-path gateways 1, 2, 3 in response to codec-bypass negotiation messages initiated by endpoint gateway A and subsequently exchanged amongst the various other gateways in the path between endpoint gateways A and B. In particular, once a call is established, all codec-bypass-compliant gateways will start monitoring the bearer to detect codec-bypass negotiation messages. In addition to monitoring, those gateways that will have self-identified themselves as active will start transmitting codec-bypass negotiation messages. Optionally, the active in-path gateways can wait for a finite time period before initiating codec-bypass transmissions. This is meant to give priority to transmissions initiated by endpoint gateways.
[0037] Thus, for example, at 220 , endpoint gateway A starts by transmitting an initial codec-bypass negotiation message 202 . The initial message 202 carries the codec information regarding endpoint gateway A, specifically a list of codec types and configurations supported by endpoint gateway A. In this case, the codec information identifies “codec X” as being supported at endpoint gateway A. Optionally, an endpoint gateway can provide a designated data element (e.g., a single bit) to identify its codec-bypass messages as having emanated from one end of the end-to-end connection in question.
[0038] When the ith in-path gateway (denoted GW(i) for convenience) receives the initial message 202 originated from endpoint gateway A, and if the codec type and codec configuration listed in the initial message 202 matches in-path GW(i)'s internally supported codec type and configuration, then in-path gateway GW(i) will return a response message towards endpoint gateway A through in-path gateways GW(i-1), GW(i-2), etc. The purpose of the response message is to signal to in-path gateway GW(i-1) and beyond (towards the endpoint gateway A) that in-path gateway GW(i) has the ability to support a compatible codec type and configuration. In-path gateway GW(i) thus goes through the process of identifying itself as a candidate gateway, capable of terminating the current codec-bypass negotiation with endpoint gateway A. In-path gateway GW(i) therefore self-identifies itself as an “active” gateway. However, as the response message travels towards endpoint gateway A, any previously determined active gateways in the chain will re-self-identify itself as a passive gateway upon receipt of the response message.
[0039] For example, at 222 , in-path gateway 1, upon receipt of the initial message 202 , realizes that it has a compatible codec type and configuration (namely, codec X). This causes the in-path gateway 1 to make a “mental note” of the fact that it is now active, i.e., in-path gateway 1 is now a candidate for terminating the codec-bypass negotiation with endpoint gateway A. The making of a “mental note” can take many forms, such as self-identification by way of setting a binary flag whose two states correspond to active and passive, respectively. This also results in in-path gateway 1 sending a response message 204 back to the endpoint gateway A. Meanwhile, gateway 1 forwards the initial message 202 towards in-path gateway 2.
[0040] At 224 , in-path gateway 2, upon receipt of the initial message 202 , realizes that it has does not have a codec type and configuration compatible with “codec X”. In-path gateway 2 therefore plays the role of a passive gateway. Under such circumstances, in-path gateway 2 simply forwards the initial message 202 towards in-path gateway 3 without any indication back towards in-path gateway 1.
[0041] At 226 , in-path gateway 3, upon receipt of the initial message 202 , realizes that it has a codec type and configuration compatible with “codec X”. Accordingly, the in-path gateway 3 makes a “mental note” of the fact that it is now active, i.e., in-path gateway 3 is now a candidate for eventually terminating the current codec-bypass negotiation with endpoint gateway A. Again, the making of a “mental note” can take many forms, such as self-identification by way of setting a binary flag whose two states correspond to active and passive, respectively. This also results in in-path gateway 3 forwarding the initial message 202 towards endpoint B, while sending a second response message 206 back to the in-path gateway 2.
[0042] At gateway 2, being a passive gateway, the second response message 206 is simply forwarded to in-path gateway 1. However, a different effect is produced at in-path gateway 1, which had previously self-identified itself as active. The receipt of the second response message 206 by the in-path gateway 1 sigls to the in-path gateway 1 that a gateway further down the chain towards endpoint gateway B is now active due to its capability of terminating the current codec-bypass negotiation. Therefore, in-path gateway 1 switches its mode of operation to “passive”.
[0043] The above-described process stops when a particular in-path gateway receives a message, i.e. a codec-bypass message transmitted by endpoint gateway B, or when a self-identified candidate fails to receive any codec-bypass messages, e.g. due to absence of the endpoint gateway B for end-to-end codec-bypass connection. In the former case, the self-identified candidate will go into passive mode only temporarily, in order to relay the codec-bypass message back towards endpoint gateway A, so as to allow end-to-end codec-bypass negotiation. If the end-to-end negotiation between endpoint gateways A and B is successful, all in-path gateways, including the one that temporarily went into passive mode, remain in passive mode. However, in the case where there is no end-to-end codec-bypass connection due to a negotiation failure, the last self-identified codec-bypass candidate will transmit a message in an attempt to start a codec-bypass negotiation with endpoint gateway A.
[0044] Thus, for example, at 228 , endpoint gateway B does not have a codec type and configuration compatible with “codec X”. Therefore, endpoint gateway B either does not send a message back to gateway 3, or (as illustrated) endpoint gateway B sends a neg_fail message 208 (negotiation failure) towards in-path gateway 3. Receipt of the neg_fail message 208 and in-path gateway 3 signals to the in-path gateway 3 that it is the furthest gateway from endpoint gateway A that is capable of terminating the codec-bypass negotiation. Accordingly, as shown in FIG. 1A, in-path gateway 3 negotiates a codec-bypass connection with endpoint gateway A.
[0045] Of course, it is also possible that no end-to-end codec-bypass connection is possible due to sheer absence of endpoint gateway B. This scenario, shown in FIG. 1B, causes basically the same end result, with the active in-path gateway furthest along the path from endpoint gateway A transmitting a response message in an attempt to start negotiation of a codec-bypass connection with endpoint gateway A.
[0046] At the same time that endpoint gateway A attempts to dialogue with gateways further along the path towards endpoint gateway B, endpoint gateway B itself may be attempting to dialogue with gateways further along the path towards endpoint gateway A. By completing analogous processes for both endpoint gateways A and B (and waiting until both options have been explored), a codec-bypass communication with the longest possible span from either endpoint can be established.
[0047] As illustrated in FIG. 1C, there also could be a scenario in which the end-to-end codec-bypass negotiation fails due to codec mismatch, but where the possibility of overlap between two possible codec-bypass connections nonetheless exists. The two active in-path gateways (from both ends) have knowledge if the end-to-end mismatch resolution was attempted or not (e.g., via presence or absence of exchanged request and acknowledge messages). After the active in-path gateways confirm the scenario, a codec-bypass solution can be provided. In short, codec-bypass negotiation between an in-path gateway with a terminating gateway will not be disrupted by a codec-bypass attempt by the remote endpoint gateways.
[0048] Specifically, as per the existing codec-bypass decision algorithm or codec mismatch resolution rules, all codecs are ranked in preference. During the scenario being contemplated, there are two incompatible codec types/configurations at endpoint gateways A and B, but each can establish a respective codec-bypass connection with a different one of the in-path gateways (namely in-path gateway 3 with endpoint gateway A and in-path gateway 2 with endpoint gateway B). An active in-path gateway which has identified itself as the codec-bypass candidate for termination of codec-bypass negotiation in one direction but which supports a less preferred codec type/configuration will continue to send a response message (e.g., 204 or 206 in FIG. 2) in order to maintain its candidacy; however, it will refrain from initiating codec-bypass negotiation for a certain delay after the scenario is entered. This is meant to allow an active in-path gateway supporting the preferred codec type/configuration to initiate the codec-bypass negotiation first.
[0049] In the example of FIG. 1D, if codec X is preferred to codec Y, then in-path gateway 3 will initiate a codec-bypass negotiation with terminating gateway A while in-path gateways 1 and 2 remain passive. Both in-path gateways 2 and 4 can initiate codec-bypass negotiation with endpoint gateway B after the specified delay. If there is no codec-bypass connection established across in-path gateway 2, in-path gateway 2 may optionally transmit a message to initiate a codec-bypass negotiation with endpoint gateway B. However, as is the case in the illustrated embodiment, a codec-bypass connection is established between endpoint gateway A and in-path gateway 3, which means that in-path gateway 2 self-identifies itself as passive. Therefore, in-path gateway 4 will not receive the response message ( 204 or 206 ) from in-path gateway 2 and will therefore remain self-identified as active, i.e., it is a candidate for terminating the codec-bypass negotiation with endpoint gateway B. (This design is applicable to all other in-path gateways in the chain supporting codec Y.) In this manner, the furthest in-path gateway from endpoint B which supports codec Y and is outside the codec-bypass connection between endpoint gateway A and in-path gateway 3 is sought for the purposes of initiating codec-bypass negotiation with in-path gateway 4. In the illustrated embodiment, this title is held by in-path gateway 4, which supports codec Y and is outside the codec-bypass connection between endpoint gateway A and in-path gateway 3. As a result, two separate non-overlapping codec-bypass connections can be established. Generally speaking, the present invention allows for more than one segment of codec-bypass negotiations.
[0050] An in-path gateway that detects codec-bypass negotiation messages only from one “side” (as viewed in the orientation in FIGS. 1A-1D and 2 ) can become a codec-bypass termination point. If codec-bypass transmissions are detected on both sides (labeled “left” and “right” sides for Packet GW, and “packet” and “TDM” for TDM GW), the behavior of (active) gateways is determined based on the mutual vocoder compatibility of the two remote nodes, as well as that of the gateway itself. Tables 1-4 define the behavior of Packet and TDM gateways under specific embodiments of the present invention.
[0051] As an enhancement, a data element (e.g., a single bit) can be used to identify cases in which a gateway needs to receive traffic in the “original” compression format (i.e. compression format at the time of call setup—e.g., G.711) even after establishment of a codec-bypass connection. This bit can be used in two cases. Firstly, it will be used by passive gateways to make sure that adjacent gateways will continue to send them the traffic signal in the original format (e.g., G.711) as well as in other compressed formats after the establishment of a codec-bypass connection. Secondly, this bit will also be used by active TDM gateways that may not be able to support the codec selected for establishment of a codec-bypass connection, to request that adjacent gateways continue to send them the traffic signal in the original format (e.g., G.711) as well as in other compressed formats after the establishment of a codec-bypass connection.
TABLE 1 Packet gateway codec compatibility when adjacent gateways do not require original codec format GW/ GW/ Left/ Left Right Right Resolution X X Y Gateway is passive towards both end nodes. “Left” and “Right” switch to common codec Y Y N Depending on the availability of CPU resources, gateway can be active towards either or both end nodes independently to achieve bandwidth and/or delay optimization N Y N Gateway is active towards right-side end node Y N N Gateway is active towards left-side end node N N N Gateway is passive towards both end nodes. Codec- bypass negotiation cannot be terminated with either end.
[0052] [0052] TABLE 2 TDM Gateway codec compatibility when adjacent packet gateway and TDM-side node do not require original codec format GW/ GW/ Packet/ Packet TDM TDM Resolution Y Y Y Gateway is passive towards both end nodes. Packet-side and TDM-side end nodes switch to common codec. N N Y Gateway is passive towards both end nodes. Codec-bypass negotiation cannot be terminated with either end node, although end-to-end codec-bypass negotiation may transit the gateway. Sets bit to indicate (to packet side) that it requires traffic in the format that was in use at call setup N N N Gateway is passive towards both end nodes. Codec-bypass negotiation cannot be terminated with either end node Y N N Gateway is active towards packet-side end node Y N Y Gateway is active towards packet-side end node. Alternatively, gateway can remain passive to allow codec-bypass negotiation to transit the gateway. In such case, set bit to indicate (to packet side) that traffic is required in the format that was in use at call setup N Y N Gateway is active towards TDM-side end node N Y Y Gateway is active towards TDM-side end node. Alternatively, gateway can remain passive to allow codec-bypass negotiation to transit the gateway. In such case, set bit to indicate (to packet side) that traffic is required in the format that was in use at call setup
[0053] [0053] TABLE 3 Packet gateway codec compatibility when “left” gateway requires original codec format GW/ GW/ Left/ Left Right Right Resolution Y Y Y Gateway is active towards the right-side end node and towards the left-side end node Y N Y Gateway is passive towards both end nodes. Sets special bit towards “right” to indicate the need to support original codec format. Codec-bypass negotiation will transit the gateway N Y Y Gateway is passive towards both end nodes. Sets special bit towards “right” to indicate the need to support original codec format. Codec-bypass negotiation will transit the gateway. Alternatively, gateway can be active towards the right-side end node N N Y Gateway is passive towards both end nodes. Sets special bit towards “right” to indicate the need to support original codec format. Codec-bypass negotiation will transit the gateway N N N Gateway is passive towards both end nodes. Codec-bypass negotiation cannot be terminated with either end node Y N N Gateway will be active towards the left-side end node N Y N Gateway will be active towards the right-side end node Y Y N Depending on CPU availability, gateway will be active towards the left-side end node and/or the right-side end node
[0054] [0054] TABLE 4 TDM gateway codec compatibility when adjacent packet gateway requires original codec format GW/ GW/ Packet/ Packet TDM TDM Resolution Y Y Y Gateway is passive towards both end nodes N N Y Gateway is passive towards both end nodes. Codec-bypass negotiation cannot be terminated with either end node, although end-to-end codec-bypass negotiation may transit the gateway. Sets bit to indicate (to packet side) that it requires traffic in the format that was in use at call setup N N N Gateway is passive towards both end nodes. Codec-bypass negotiation cannot be terminated with either end Y N N Gateway is active towards the packet-side node Y N Y Gateway is active towards packet-side end node. Alternatively, gateway can remain passive to allow codec-bypass negotiation to transit the gateway. In such case, set bit to indicate (to packet side) that traffic is required in the format that was in use at call setup N Y N Gateway is active towards the TDM-side node N Y Y Gateway is active towards TDM-side end node. Alternatively, gateway can remain passive to allow codec-bypass negotiation to transit the gateway. In such case, set bit to indicate (to packet side) that traffic is required in the format that was in use at call setup Y Y N Depending on the availability of CPU resources, gateway can be active towards either or both end nodes independently to achieve bandwidth and/or delay optimization
[0055] It should be understood that other modifications of, and additions to, the present invention are possible. For example, the self-identification process described herein above is applicable to the various example, non-limiting scenarios depicted in FIGS. 3 to 8 .
[0056] Also, it is recalled that the rules and procedures above essentially lead to clarification of a particular in-path gateway's disposition. Specifically, a codec-bypass-compliant in-path gateway will know whether or not it is the last in-path gateway and whether or not it has vocoders common with each of the endpoints. Equipped with this information, should a codec-bypass connection fail to establish due to the absence of a compatible codec type or configuration at either end, the above methods can be applied recursively in order to come up with codec-bypass connection segments where applicable, for the purpose of reducing bandwidth where applicable. The recursive application of the procedure means that the last in-path gateways (rather than the endpoint gateways) would initiate their own search for codec-bypass partners based on their full suite of supported vocoders. In initiating the codec-bypass handshaking these gateways will also take advantage of their knowledge of the vocoders supported by the endpoints to achieve maximum bandwidth savings and voice quality. A pre-defined vocoder order of preference will guide the application of the procedure, e.g., in situations where each of the two last in-path gateways supports the vocoder of different endpoints only. The prescribed order of vocoder preference will determine which of the two last in-path gateways will initiate the new round of codec-bypass handshaking. The in-path gateway which supports a vocoder with a lower priority will wait for a prescribed period of time before initiating its own codec-bypass handshaking. This priority scheme prevents race conditions that may lead to instability.
[0057] Should the procedure initiated by the last in-path gateways fail to achieve codec-bypass mode of operation due to the absence of common vocoders, the recursion can be applied again to search for yet more limited application of codec-bypass mode of operation. Thus, the in-path gateways can identify themselves to be in the middle of the path, rather than the last in-path gateway, by monitoring codec-bypass exchanges around them including the usage of a suitable message. Again, the procedure may result in several segments of codec-bypass negotiations, i.e. not limited to a single segment.
[0058] Those skilled in the art will appreciate that the control entity of each gateway may be implemented as an arithmetic and logic unit (ALU) having access to a code memory (not shown) which stored program instructions for the operation of the ALU. The program instructions could be stored on a medium which is fixed, tangible and readable directly by the processor, (e.g., removable diskette, CD-ROM, ROM, or fixed disk), or the program instructions could be stored remotely but transmittable to the processor via a modem or other interface device (e.g., a communications adapter) connected to a network over a transmission medium. The transmission medium may be either a tangible medium (e.g., optical or analog communications lines) or a medium implemented using wireless techniques (e.g., microwave, infrared or other transmission schemes).
[0059] Those skilled in the art should also appreciate that the program instructions stored in the code memory can be compiled from a high level program written in a number of programming languages for use with many computer architectures or operating systems. For example, the high level program may be written in assembly language, while other versions may be written in a procedural programming language (e.g., “C”) or an object oriented programming language (e.g., “C++” or “JAVA”).
[0060] Those skilled in the art should further appreciate that in some embodiments of the invention, the functionality of the control entity may be implemented as pre-programmed hardware or firmware elements (e.g., application specific integrated circuits (ASICs), electrically erasable programmable read-only memories (EEPROMs), etc.), or other related components.
[0061] While specific embodiments of the present invention have been described and illustrated, it will be apparent to those skilled in the art that numerous modifications and variations can be made without departing from the scope of the invention as defined in the appended claims.
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Communication apparatus having interfaces for exchanging data with first and second neighbors, a memory for storing codec information regarding the communication apparatus and a control entity operative to detect a message from the first neighbor, the first message being indicative of codec information regarding an originating entity. In response, the control entity assesses compatibility between the codec information regarding the originating entity and the codec information regarding the communication apparatus. If the assessment is positive, the control entity self-identifies the communication apparatus as a candidate for terminally supporting a subsequent codec-bypass negotiation with the originating entity. If the assessment is negative, the control entity self-identifies the communication apparatus as a candidate for non-terminally supporting such negotiation. The invention thus capitalizes on the realization that although an end-to-end codec-bypass connection may not be possible, it may nevertheless be possible to achieve bandwidth savings by establishing a codec-bypass connection along only a portion of the path.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method for manufacturing an elastic sealing ring for sealing between a displaceable and/or rotatable component, such as a piston, piston rod, shaft etc., and a surrounding component, such as a cylinder block, a cylinder end wall etc., which sealing ring is adapted so as to be mounted in a groove in one component and has at least one sealing surface intended for bearing against the other component.
[0002] The invention also relates to an elastic sealing ring manufactured by means of the method according to the invention.
BACKGROUND OF THE INVENTION
[0003] Sealing rings of the type indicated above are used in many situations, inter alia as hydraulic seals for pistons and piston rods. One application is as a wiper for piston rods, their task being to prevent dirt or other impurities from, for example, accompanying a piston rod into a hydraulic cylinder. They can also be used on rotating shafts which may be, for example, axially displaceable.
[0004] Another application is as a pressure seal between a piston rod and a cylinder end wall in order to prevent leakage of pressure fluid from the cylinder. A similar application is as a piston seal in order to bring about sealing between a displaceable piston and a surrounding cylinder block.
[0005] Piston rod wipers and pressure seals for piston rods are commonly used together. Conventionally, however, they have been made and mounted as two separate components. One of the reasons for this is that an elastic sealing ring, which is usually made of polyurethane, must be so soft/elastic that good sealing and bearing against the piston rod are obtained. A disadvantage of this is that the risk of gap extrusion, that is to say material being forced out into the gap between the two components which are to be sealed relative to one another, is relatively great. As the entire seal body is also made of the same relatively elastic material, the friction against the piston rod increases, the temperature in the seal material then increasing, which in turn reduces the rigidity and brings about a further increase in friction and temperature, and so forth.
[0006] In order to prevent gap extrusion, pressure seals for piston rods and piston seals are supplemented by support rings made of relatively hard plastic material, which prevent the soft polyurethane seal material being forced out into the gap. This makes manufacture, mounting and maintenance more expensive and complicated.
[0007] In wipers for piston rods, the sealing rings serving as wipers have commonly been provided with a sheet-metal surround in order to bring about secure mounting of the relatively elastic polyurethane ring in a groove in the surrounding block.
THE OBJECT OF THE INVENTION
[0008] One object of the present invention is to produce sealing rings for piston rods and pistons, in which inter alia the risk of detrimental friction heating and gap extrusion has been eliminated or greatly reduced.
[0009] This makes it possible inter alia for the sealing rings to be mounted without separate support rings, which makes manufacture, mounting and maintenance of the seals considerably easier and less expensive.
[0010] The invention is based on the knowledge that this aim can be achieved by manufacturing a sealing ring by injection-molding two materials with different properties, so that a core made of one material is obtained, which is surrounded by a thin layer of another material with in part other properties.
[0011] In this connection, the inner material is to be sufficiently elastic in order to give the sealing ring the dynamic properties which are required for good flexibility and sealing action. This inner core material is surrounded by a thin layer of an outer material with low friction, which inter alia reduces friction heating of the seal material. Such heating otherwise reduces the rigidity of the seal material, which increases the risk of gap extrusion. In order further to reduce this risk, the outer layer can be made of a harder material than the core.
[0012] It is then, according to the present invention, especially characteristic of a method of the type indicated in the first paragraph that the sealing ring is manufactured by simultaneous injection-molding of two materials with different properties, so that it has an inner core made of a first material with first properties and an outer layer made of a second material with in part second properties surrounding the core, and so that said sealing surface is at least partly formed by a part of said outer layer with said second properties.
[0013] By means of this method, it is possible to produce a sealing ring with lower friction heating of the seal material, which in itself reduces the risk of gap extrusion. The material in the outer layer can also be selected so that the tendency toward gap extrusion is, further reduced.
[0014] The sealing ring is preferably manufactured by the two materials being injected sequentially into a mold, said second material being injected into the mold first, after which said first material is injected centrally into the mold, so that it forces the second material injected first out against the delimiting surfaces of the mold cavity. Alternatively, the two materials can be combined in a unit located ahead of the mold, such as a plasticizing chamber or a nozzle, before they are injected together into the mold cavity. In both cases, it is possible to obtain a core made of the first material, which is surrounded by an outer layer of essentially uniform thickness made of the second, harder material.
[0015] It is preferred that, as said second material, a material is injected which gives lower friction on contact with a component bearing against it than the first material, the second material preferably having a greater hardness than the first material.
[0016] The materials can be injected into a mold which produces a dish-shaped blank, the peripheral outer edge portion of the blank being essentially V-shaped or U-shaped with two sealing lips for forming a pressure seal for a piston rod or the like, the sprue dish being cut away, so that the other end of the annular product obtained is shaped to form a piston rod wiper lip.
[0017] By means of this method, a combined wiper and pressure seal is therefore produced, which can be both manufactured and mounted in a single corresponding operational step without the use of separate support rings or the like.
[0018] The especially characteristic features of an elastic sealing ring manufactured according to the present invention emerge from the patent claims below.
[0019] The invention will be described in greater detail below with reference to the embodiments shown by way of example in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0020] [0020]FIG. 1 illustrates known art for sealing a hydraulic piston with a piston rod.
[0021] [0021]FIG. 2 shows a part of a blank for a wiper according to the present invention.
[0022] [0022]FIG. 3 shows a part of a blank for a piston rod seal according to the invention.
[0023] [0023]FIG. 4 shows a part of a blank for a combined piston rod seal and wiper according to the invention.
[0024] [0024]FIG. 5 illustrates the sealing of a hydraulic piston with a piston rod using sealing rings according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] In FIG. 1, which shows known art, reference number 1 designates a cylinder block and 2 a piston which is displaceable in the block and has a piston rod 3 projecting through the end wall of the block. The piston 2 is provided with an elastic sealing ring 6 made of an elastomer, suitably a polyurethane material, arranged in a groove 5 . To bring about the necessary sealing, the polyurethane material must be relatively soft, which involves risks of gap extrusion, that is to say the risk that the seal material will be pressed into and crushed in the gap between the piston 2 and the surrounding cylinder block 1 . For this reason, the sealing ring 3 is supported on both sides by means of a pair of support rings 7 made of hard plastic material. Reference number 8 designates two guides for keeping the piston 2 centered in the cylinder.
[0026] The piston seal therefore consists overall of a number of components which have to be manufactured and mounted separately, which increases costs. The relatively soft material in the sealing ring 6 also results in increased friction which inter alia increases friction heating etc. All in all, this increases the risk of the seal material being damaged on account of friction heating.
[0027] Reference number 9 designates a so-called U packing ring which forms a pressure seal in order to prevent hydraulic oil from being pressed out from the cylinder along the piston rod 3 . The pressure seal has two sealing lips 10 which will be pressed apart by the hydraulic pressure and then bring about good sealing of the piston rod 3 . For this reason, the pressure seal 9 also has to be made of a relatively soft seal material with the attendant risk of detrimental friction heating. Furthermore, a support ring 11 is required in order to reduce the risk of gap extrusion as mentioned above.
[0028] Reference number 12 relates to what is known as a piston rod wiper with an annular wiper lip 13 bearing against the piston rod 3 . This prevents dirt and other impurities from accompanying the piston rod into the hydraulic cylinder. To function well, the wiper 12 also has to be manufactured from a relatively soft seal material. On mounting in an open groove 14 in the cylinder end wall, a sheet-metal surround 14 is usually embedded in the wiper, which can be pressed firmly into the groove 14 by means of a press fit.
[0029] In order inter alia to avoid the high friction of previously used sealing rings manufactured from a soft seal material throughout with the attendant friction heating and risk of gap extrusion, sealing rings for inter alia piston rod wipers, piston rod seals and piston seals are manufactured according to the present invention by double injection of two plastic materials with in part different properties. In this way, it is possible to produce sealing rings with an outer layer with relatively low friction in order inter alia to reduce friction heating and the risk of gap extrusion, and with a softer inner core which gives the sealing ring the necessary flexibility and adaptability so as to provide good sealing action. In order further to reduce the risk of gap extrusion, the outer layer is made of a harder material than the core.
[0030] [0030]FIG. 2 shows a section through one half of a dish-shaped blank, produced in a mold by double injection, for a piston rod wiper 16 according to the present invention. The blank has an inner core 17 made of a relatively elastic seal material, for example of polyurethane with a hardness of 40-70° Shore D, preferably roughly 50-60° Shore D. The core 17 is surrounded by a relatively thin outer layer 18 with a thickness of the order of 0.2-0.6 mm, preferably roughly 0.4 mm. The outer layer also suitably consists of a polyurethane material which, however, is harder than the material in the core 17 and has a hardness of the order of 85-95° Shore D, preferably roughly 90-93° Shore D. This harder outer layer results in low friction against the piston rod and thus low friction heating as well. On account of the softer core 17 , however, good flexibility and adaptability of the sealing ring are obtained for maintaining a good sealing function.
[0031] The blank shown is manufactured by simultaneous injection-molding of the two plastic materials. This can be carried out by sequential injection of the two plastic materials into a mold. In this connection, the harder material, which is to form the outer layer 18 of the sealing ring, is injected first. Then, the material for the core 17 is injected centrally into the mold, this material, when injected, forcing the material injected first out against the delimiting surfaces of the mold cavity, so that the latter material will form an outer layer 18 which surrounds the softer material in the core 17 .
[0032] If the wiper is to be provided with a sheet-metal surround 15 , such a surround is positioned in the mold before the plastic materials are injected, so that it will be molded integral with the outer layer 18 .
[0033] After mold removal, the sprue dish 20 formed is cut off along an angled cutting line 21 , so that a cut surface as illustrated in the figure is obtained. The outer layer 18 on the inner surface of the ring will then form a sealing lip 19 which bears against a piston rod which is guided through the sealing ring. This means that it is the harder material in the outer layer 18 which bears against the piston rod, which results in reduced friction and thus reduced friction heating in comparison with previously known wipers. The flexibility of the wiper lip 19 will be retained, however, on account of the softer material in the core 17 of the wiper ring.
[0034] [0034]FIG. 3 illustrates in a corresponding manner one half of a blank for a piston rod seal 22 after mold removal. As in FIG. 2, the blank consists of a core 17 made of a soft plastic material, which is surrounded by an outer layer 18 made of a harder material. The sprue dish 20 is cut away, and the two end portions of the V-shaped sealing collar are chamfered along the lines 23 and 24 . In this way, a sealing lip 25 with the cross section shown bearing against a piston rod guided through the collar, and a sealing lip 26 bearing against the bottom in a groove in a surrounding cylinder end wall are formed.
[0035] The pressure from the hydraulic oil in the cylinder will penetrate the V shape between the sealing lips 25 and 26 and press these away from one another to bear in a sealing manner against the piston rod and, respectively, the cylinder block. In both cases, the bearing part of the sealing lip consists of the outer harder material 18 , but the sealing lip still has good flexibility on account of the inner, softer core 17 .
[0036] [0036]FIG. 4 illustrates a blank for a combined piston rod wiper and piston rod seal. As previously, the blank is constructed from a relatively flexible core 17 and a harder outer layer 18 . The sprue dish 20 is cut off along a cutting line 27 to form a piston rod wiper lip 28 , as described above in connection with FIG. 2. At the other end, the end portions of the blank are chamfered along the lines 29 and 30 to form sealing lips 31 and 32 for bearing against a surrounding cylinder block and, respectively, a piston rod.
[0037] The part serving as the piston rod wiper is connected to the part serving as the piston rod seal via a relatively thin portion 33 which barely fills the gap present between the piston rod and the cylinder end wall. This portion and the shoulder surfaces 34 and 35 delimiting it make it possible for the combined seal and wiper to be anchored securely in the cylinder block. On account of the hard material in the outer layer 18 , the risk is also eliminated of the seal material in the piston seal penetrating the gap between the piston and the cylinder end wall, which is also to a great extent filled by the material portion 33 .
[0038] The fitting of the combined seal shown in FIG. 4 can be seen in FIG. 5 which, shows the application of sealing elements according to the invention in a hydraulic cylinder of the same type as is shown in FIG. 1.
[0039] As previously, the reference numbers 1 , 2 and 3 relate to a cylinder block, a piston and, respectively, a piston rod which projects through the cylinder block. The reference numbers 8 relate to guides for the piston 2 and the piston rod 3 .
[0040] Arranged between the end wall of the cylinder block 1 and the piston rod 3 is a combined sealing element according to FIG. 4. This comprises a wiper lip 28 which bears against the piston rod 3 , and a piston rod seal with a sealing lip 32 for bearing against the piston rod 3 and a sealing lip 31 for bearing against the bottom surface of a groove in the cylinder end wall. The sealing lips 31 and 32 are pressed away from one another on account of hydraulic oil entering the V-shaped space between these sealing lips.
[0041] By virtue of the fact that the sealing element according to the above is manufactured with a softer core and a harder outer layer, a sealing element is obtained with low friction and low friction heating but which still has the necessary flexibility for bringing about good sealing action. Manufacture and mounting are made easier and less costly, as it is necessary to handle only one element without a requirement for extra support rings or equivalent.
[0042] In the same way, the piston seal is made with a softer core 36 and a harder outer layer 37 . This affords the same advantages as indicated in connection with the piston rod seal and means that no extra support rings for preventing gap extrusion are required. This means lower costs for the piston seal as well, as inter alia separate support rings do not have to be manufactured, mounted or maintained.
[0043] Another advantage is that sealing rings according to the invention can be made in undivided form, as the elasticity is sufficient for it to be possible for these to be pulled onto, for example, a piston or a piston rod. The support rings used previously had to be mounted in sections as they were too inelastic to be slipped onto, for example, a piston.
[0044] The lower friction of the outer layer results in itself in a reduced risk of gap extrusion on account of lower friction heating and thus a smaller reduction in the rigidity of the material. In this connection, the outer layer can consist of the same material as the core but with an addition of a friction-reducing substance, such as Teflon powder.
[0045] The invention has been described above in connection with the embodiments shown in the drawings. It can, however, be varied in a number of respects within the scope of the patent claims below. The technique described can therefore also be used for other sealing rings with other configurations and intended for other applications than those described above. The necessary modifications can then be performed easily by a person skilled in the art. In this connection, the material combinations can also be changed if so desired or required, and the indicated material thicknesses and hardnesses can be varied depending on the circumstances.
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Elastic sealing ring for sealing between a displaceable and/or rotatable component, such as a piston ( 2 ), piston rod ( 3 ), shaft etc., and a surrounding component, such as a cylinder block ( 1 ), a cylinder end wall etc. The sealing ring is adapted so as to be mounted in a groove in one component and has at least one sealing surface ( 28; 31, 32 ) intended for bearing against the other component, and comprises two materials with different properties. The sealing ring is made with an inner injection-molded core ( 17 ) made of a first material with first properties and an outer layer ( 18 ) made of a second material with in part second properties and injection-molded together with the core. This material is fused together with the material in the core in the boundary zone. The sealing surface is at least partly formed by a part of the outer layer ( 18 ), which has lower friction on contact with a component part bearing against it than the material in the core ( 17 ). The invention also relates to a method for manufacturing a sealing ring as above.
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TECHNICAL FIELD
[0001] The present invention relates to a water-permeable fabric covering for bar-form personal hygiene soaps, and more particularly, to fabric soap-bar cover that exhibits the ability to conform to the shape of the soap-bar and yet maintain a essentially planar surface suitable for further application of performance and/or aesthetic enhancing agents.
BACKGROUND OF THE INVENTION
[0002] The practice of employing washcloths and similar bathing articles during the conduction of personal hygiene cleansing is well known. The use of a washcloth allows for improved abrasiveness imparted by the surface of the washcloth combined with improved soap retention when soaps are either applied thereon or used separately.
[0003] Washcloth materials have historically been composed of woven cotton fabrics, such as terrycloth. A deleterious effect realized in the daily use of a natural fiber woven washcloths is that due to the entrainment of exfoliated skin, dirt and oils into the washcloth, combined with the moist environment common to bathrooms, bacterial growth is encouraged. Bacterial growth is undesirable in a washcloth as propagation of the bacteria results in an accompanying malodor and reduced sanitary conduction contradictory to the purpose for which a washcloth is intended. A natural fiber woven washcloth must be laundered frequently in order to remove these contaminants and thereby return the washcloth to a useable state.
[0004] To improve upon the performance of natural fiber washcloths, fabricators of such articles have focused upon the use of synthetic materials. Synthetic materials, and particularly plastic resins, offer many advantages in washcloth construction. Of particular importance is the use of plastic resins result in a washing matrix that is resilient to bacterial growth due to the lower surface energies inherent to the plastic versus a natural fiber. Further, plastics can be treated during the formation of the washing matrix with agents that impart a biocidal or biostatic performance. The combination of inherent and active bacterial growth reduction due to the use of plastic resins results in a washcloth that can be used for a longer period than a natural fiber woven washcloth.
[0005] The combination of a washcloth with the detergent source has been of particular interest in the formation of washcloths or similar bathing aids with enhanced performance and appeal.
[0006] U.S. Pat. Nos. 4,510,641 and 4,665,580, both to Morris, teach the application of a multilayered scouring pad about a central pocket in which to receive a detergent, the layers consisting of metallic nonwoven materials superimposed on supporting netting layers.
[0007] U.S. Pat. No. 4,733,426 to George, addresses the fouling problem inherent to sponges by encasing a sponge within an elastic woven covering.
[0008] U.S. Pat. No. 4,969,225 to Schubert, describes a scrub brush whereby the soap-bar becomes integrated into the lofty, fibrous structure and once integrated, becomes the internal backbone of the scrub brush.
[0009] U.S. Pat. No. 6,042,288 to Rattinger, et al., employs a detergent in the form of a soap-bar encased within a sponge structure consisting of multiple layers of tubular netting. The overall construct is highly three-dimensional, the inventors having described the combination of soap-bar and sponge as being “ball like”.
[0010] U.S. Pat. No. 6,085,380 to Gonda, et al., focus upon a derivation of washcloth whereby a pouf is formed from a spiral wound thermoplastic filament. The user treats the pouf with a separate liquid or gel detergent prior to application in bathing. U.S. Pat. No. 6,026,534, also to Gonda, et al., utilizes a pouf constructed of independent, finite length filaments extending from a central core and resulting a spherical construct. Again, a detergent is applied to the pouf prior to use.
[0011] There is a prevalence of “net” type enclosures, whereby the soap-bar is placed simply in the confines of an oversized bag constructed of open mess fabrics. U.S. Pat. Nos. 3,167,805, 4,228,835, 4,480,939 and 5,462,378 typify patents teaching to this general construct A problem inherent to soap-bar covers designed heretofore is the combined effect of excessive material consumption, with a corresponding increase in construction difficulty and cost necessary to fabricate such covers, and the resulting highly bulky nature of these covers is such that packaging is also made more difficult and costly. Further, there is a desire by both the users and fabricators of such soap-bar covers to have an article with enhanced performance and aesthetics capabilities. There remains an unmet need for a soap-bar covering which reduces the consumption level of material components yet exhibits suitable design flexibility to address performance and aesthetics issues
SUMMARY OF THE INVENTION
[0012] The present invention is directed to a soap-bar cover comprising a water-permeable fabric, and particularly a soap-bar cover exhibiting a stretch and recovery performance while maintaining a substantially planar surface. Soap-bar covers fabricated in accordance with the present invention are particularly useful as a means for enhancing the cleansing properties of commercially available soap-bar products.
[0013] The soap-bar cover is composed of a woven or nonwoven fabric exhibiting stretch and recovery properties. Use of a stretch and recovery fabric in the soap-bar cover allows for the cover to conform to the contours of the soap-bar and is thus able to adjust to a wide variety of soap-bar profiles including cubic and ovoid. Further, as an initial soap-bar is consumed during application in personal hygiene applications, a second soap-bar, of same or different profile, can be inserted and consumed in conjunction with the remnants of the initial soap-bar.
[0014] Suitable woven fabrics include primary knits, warp or circular knits, weft insertion, or woven fabrics including stitch-through technologies, and may include such fibers and filaments that exhibit an inherent elasticity, such as typified by aliphatic-aromatic polyesters and other elastomers.
[0015] A suitable nonwoven fabric may be selected from conventional means well known in the art, including the use of staple fiber, continuous filaments, and the combinations thereof. Such fibers and filaments may either exhibit an inherent elasticity, such as typified by aliphatic-aromatic polyesters and other elastomers, or be rendered elastic by application of specialized elastic binding chemistries. An exemplary nonwoven fabric embodying the principles of the present invention comprises a hydroentangled nonwoven web preferably comprising staple length textile fibers of about 0.8 to 15.0 denier having a basis weight of about 0.5 to 8.0 ounces per square yard, preferably 2.0 to 4.0 ounces per square yard. More preferably, the nonwoven web comprises fibers of about 1.0 to 3.0 denier, with the web having a basis weight of about 2.5 to 3.5 ounces per square yard. Use of polyester fibers is presently preferred, but it is within the purview of the present invention to form the present nonwoven fabric from blends which include at least a portion of synthetic fibers blended with natural fibers, and from substantially continuous filaments of either homogeneous or multi-component polymeric construction.
[0016] In a current preferred embodiment, hydroentanglement is effected so as to impart a rectilinear pattern to the fibrous or precursor nonwoven web, which pattern is preferably oriented at an angle between about 30° and 60° relative to a machine-direction of the web. In a preferred method of formation, the fibrous web is subjected to preliminary hydroentanglement to lend integrity thereto prior to formation of the rectilinear pattern in the web by hydroentanglement on a patterned forming surface.
[0017] In order to impart elastic characteristics to the nonwoven fabric to fabricate the soap-bar cover, a polymeric binder composition is substantially uniformly applied to the nonwoven fabric. Although the specific amount of binder can be varied while keeping with the principles disclosed herein, it is presently preferred that the binder composition comprises between about 17% and about 31%, by weight, of acrylic binder. Subsequent to application of the polymeric binder composition, the nonwoven web is dried to form the present nonwoven fabric. Significantly, the resultant nonwoven fabric exhibits elastic characteristics (i.e., stretch or extensibility, and recovery) in the cross-direction of the fabric. In accordance with the present invention, the fabric exhibits at least about 20% extensibility in the cross-direction, and at least about 50% recovery in the cross-direction, preferably at least about 50% extensibility in the cross-direction, with at least about 75% recovery. The fabric is thus engineered to exhibit a relatively high degree of cross-direction elasticity.
[0018] An advantage in the use of a stretch and recovery fabric as described is that a substantially planar surface of the nonwoven fabric is present on the face of the soap-bar. This substantially planar face on the nonwoven fabric is receptive to application of performance and/or aesthetic enhancing agents. Performance enhancing agents include exemplary materials such as mild abrasives, exfoliants, or skin care additives, which can be applied directly and uniformly to the substantially planar surface by conventional means. Aesthetic enhancement of the substantially planar surface includes application of alternate fragrances and the printing, or transference, of ornamental designs to at least one face of the soap-bar cover. Such ornamental designs, including related soap-bar product trademarks, hotel logos, and instruction for use, can be applied directly and legibly to the soap-bar cover. Thermochromic inks may also be used in the ornamental design applique so as to change color when heated or chilled during application in personal hygiene routines.
[0019] It is a further aspect of the present invention that a soap-bar cover enhances the aesthetic appeal of a soap-bar by reducing the ability of foreign matter to entrain in the surface of the soap-bar.
[0020] It is a further aspect of the present invention that a soap-bar cover enhances the ability of the user to retain the soap-bar product (the soap-bar within a soap-bar cover) when such soap-bar product becomes wet.
[0021] It is a further aspect of the present invention that a soap-bar cover further includes a means for suspending the soap-bar product so that excess water can drain away during periods of non-use.
[0022] Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] [0023]FIG. 1 is a diagrammatic view of one form of an apparatus for forming the present nonwoven fabric according to one form of the method of the present invention; and
[0024] [0024]FIG. 2 is a photograph of a top-plan view of an exemplary soap-bar cover assembly containing a soap-bar, the assembly inclusive of a nonwoven fabric embodying the principles of the present invention.
[0025] [0025]FIG. 3 is a photograph of a side view of an exemplary soap-bar cover assembly containing a soap-bar, the assembly inclusive of a nonwoven fabric embodying the principles of the present invention.
[0026] [0026]FIG. 4 is a photograph of a bottom top-plan view of an exemplary soap-bar cover assembly containing a soap-bar, the assembly inclusive of a nonwoven fabric embodying the principles of the present invention, into which a bar of soap is being inserted.
[0027] [0027]FIG. 5 is a photograph of a top-plan view of an exemplary soap-bar cover assembly, the assembly inclusive of a nonwoven fabric embodying the principles of the present invention.
DETAILED DESCRIPTION
[0028] 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 as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0029] U.S. Pat. No.3,485,706, to Evans, hereby incorporated by reference, discloses a process for effecting hydroentanglement of nonwoven fabrics.
[0030] U.S. Pat. No. 5,098,764, hereby incorporated by reference, discloses a nonwoven fabric having unique characteristics and properties, which permit use of the fabric in a wide variety of applications. A method and apparatus for manufacturing the fabric are also disclosed, including a hydroentanglement (sometimes referred to as spun-laced) process by which a precursor nonwoven web of fibers is subjected to hydroentanglement on a forming surface to impart a rectilinear pattern to the web. The present invention can be practiced in accordance with the teachings of this patent, and as appropriate, reference will be made to this patent in connection with the present disclosure.
[0031] U.S. Pat. Nos. 5,670,234, 5,674,587, and 5,827,597, hereby incorporated by reference, disclose a topographical support member, which can be employed for imparting a pattern to a nonwoven fabric during hydroentanglement, with the resultant fabric again having desirable properties, which lend it for use in many different applications. Fabrics formed in accordance with the teachings of this fabric are sometimes referred to as “tricot”.
[0032] The present invention contemplates use of the methods disclosed in the above-referenced patents for manufacture of soap-bar covers exhibiting elastic characteristics, that is, stretch and recovery, at least in the cross-direction of the fabric. Nonwoven fabrics typically exhibit a machine-direction and a cross-direction, that is, with reference to the direction, which extends along the length of the fabric, i.e., the direction in which it is manufactured (the machine-direction), and the direction of the fabric, which extends perpendicularly to the machine-direction, typically across the width of the fabric. Fabrication of a soap-bar cover begins with the manufacture or procurement of a suitable nonwoven fabric embodying the principles of the present invention. Manufacture of a suitable nonwoven fabric is initiated by providing a precursor nonwoven web which preferably comprises staple length textile fibers of about 0.8 to about 15.0 denier having a basis weight of about 0.5 to about 8.0 ounces per square yard. While it is contemplated that the present invention can be practiced with the use of synthetic fibers (of homogeneous and/or multi- component polymeric composition), natural fibers, and blends thereof, as well as melt-spun filaments (of homogeneous and/or multi-component polymeric composition) such as continuous spunbond filaments or melt-blown fragmentary filaments, use of 100% polyester staple fiber is presently preferred. Fiber or filament profile is not a limitation of the present invention. In current practice of the present invention, polyester staple length fibers having a denier of about 1.5 have been particularly preferred. These fibers are commercially available under the product designation 54W, from Dupont Akra.
[0033] As noted above, various combinations of fiber orientation and binder add-on can be successfully employed in achieving a nonwoven fabric exhibiting the characteristics of the present invention. Thus, the binder add-on or “finish level” of the finished nonwoven fabric can be varied in accordance with the teachings herein. It is desirable to have sufficient add-on to achieve the necessary fabric elasticity and durability.
[0034] Stretch or extensibility and recovery characteristics of the present nonwoven fabric, in the cross-direction, have been selected to facilitate use in soap-bar applications while maintaining the necessary durability and elasticity of the fabric. It is presently preferred that the nonwoven fabric of the present invention exhibit extensibility in the cross-direction of at least about 50%, and more preferably at least about 60%. It is preferred that the nonwoven fabric of the present invention exhibit initial recovery of at least about 75%, with initial recovery of at least about 85% being particularly preferred. The following test methodology is employed for testing of fabrics, with this methodology being a modification of ASTM 3107-75, re-approved 1980, hereby incorporated by reference.
[0035] The scope of the present methodology is for measuring stretch or extensibility under a constant weight for a set length of time, and for measuring recovery of stretch in the same fabric. Samples are prepared by cutting 2 inch by 20 inch (MD×CD) from the center, left side, and right side of a fabric sample. Cuts are taken no closer than 6 inches from the edge of the sample. A ruler with measurements in 0.10 inch increments is employed. The test employs one of five standardized weights (2.0, 2.5, 3.0, 3.5, or 4.0 pounds) depending upon the basis weight of the fabric, as set forth below. Starting 4 inches from the top each sample, a 10 inch section is bench marked. A clip is attached to the top of the sample and the sample is supported on a rack. Depending upon fabric basis weights, the following test weights are employed:
[0036] BASIS WEIGHT (Per Yard 2 )/TEST WEIGHT
[0037] 1.0-3.9 ounces/(2.0 pounds)
[0038] 4.0-4.9 ounces/(2.5 pounds)
[0039] 5.0-5.9 ounces/(3.0 pounds)
[0040] 6.0-6.9 ounces/(3.5 pounds)
[0041] 7.0-7.9 ounces/(4.0 pounds)
[0042] The weight assembly for the correct weight range is attached with a spring clip to the bottom of the sample. The sample is suspended, under the influence of weight, for 15 seconds. The calibrated ruler is used to measure the new, stretched length of the original sample, i.e., the distance between the ends of the original 10-inch marked section of the sample. This reading is recorded as B. The weight is removed, and the sample removed from the clips and rack. The sample is laid flat on a table or like surface. After 5 minutes to condition the sample, the relaxed length of the original sample, i.e., the distance between the ends of the 10 inch marked section is measured, thus providing record reading C.
[0043] Calculations are made in accordance with the following:
[0044] Percent stretch=(B−10)×10
[0045] Percent recovery=100 minus [(C-10)×100]
[0046] Average readings are taken from side, center, and side of the tested fabric.
EXAMPLE
[0047] A stretch and recovery 100% PET nonwoven fabric was obtained in the form of a commercially available material specified as M-037X, from Polymer Group, Inc., of Benson, N.C. The M-037X comprised a preformed nonwoven web subjected to hydraulic energy to impart a predescribed image or pattern as shown in FIG. 1 and in accordance with above-referenced U.S. Pat. No. 5,098,764. The process includes an image transfer device 24 which receives the preformed nonwoven web P and which typically imparts a final pattern to the web. The web is subjected to hydroentanglement from three nozzle assemblies, designated 26, at a line speed of approximately 35 yards per minute, and an entangling pressure of 150 bar. Each of the nozzle assemblies is preferably configured in accordance with the above-described nozzle assemblies.
[0048] Subsequent to patterned hydroentanglement, the web received a substantially uniform application of a polymeric binder composition at an application station 30. The web is then directed over a series of drying rollers 32 , operated at 310° F., with manufacture of the nonwoven fabric of the present invention thus completed.
[0049] A binder composition, comprising an elastomeric emulsion, having the following formulation has been employed in the bath of the application station.
Tween 20 (Wetting Agent) 0.2% Antifoam Y-30 (Silicone Defoamer) 0.025% 10% Aqua Ammonia 0.3% San Cure 861 (Polyurethane) 0.7% Hystretch V-29 (Acrylic Binder) X% (variable) Water Balance of Bath
[0050] The particular material utilized an image transfer device in form of “20×20” pattern prior to binder application. The “20×20” refers to a rectilinear forming pattern having 20 lines per inch by 20 lines per inch configured in accordance with FIGS. 12 and 13 of U.S. Pat. No. 5,098,764 except mid pyramid drain holes are omitted. Drain holes are present at each corner of the pyramid (four holes surround the pyramid). The “20×20” pattern is oriented 45 degrees relative to the machine direction, with a pyramidal height of 0.025 inches and drain holes having a diameter of 0.02 inches.
[0051] The durability of the M-037X greige fabric was confirmed by subjecting the fabric to a wash durability test. The wash durability test comprises subjecting sheets of fabric to a wash cycle including the use of a laundry type detergent, followed by drying the fabric through the use of a residential through-air dryer. A total of 25 test cycles were run, with stretch and recovery testing being performed at the 0, 5, 10, 15, 20, and 25 cycle points. The data is provided in TABLE 1.
[0052] Prior to using the greige fabric to construct an exemplary soap-bar cover assembly; the fabric was pre-treated with a softening agent followed by jet dyeing and mechanical compaction to a level of 7%. Any suitable conventional textile dyeing can be employed, including, but not limited to, jet, beam, continuous range, pad, and garment. In addition, rotary screen-printing, heat transfer printing, digital printing, and flexographic printing can be applied solely or in conjunction with a dyeing procedure. It is also within the purview of the present invention that a mechanical treatment or treatments may be employed, either prior to or subsequent to printing and dyeing, to include such processes as sanforizing, micrexing, sanding, sueding, napping, or application of either the Bianchalanni or Scutcher process.
[0053] The nonwoven fabric was then used to fabricate a soap-bar cover in accordance with the present invention. A needle size of 70 was utilized in conjunction with a Tex 21 perma-spun sewing thread at a range of between 9 to 11 stitches per inch. As will be appreciated, alternative techniques can be employed for forming the present cover from the above-described nonwoven fabric, including ultrasonic bonding, adhesive bonding and needlepunching.
[0054] [0054]FIGS. 2 through 5 illustrate an exemplary soap-bar cover assembly formed in accordance with the present invention. The soap-bar cover assembly includes a mutual combination of a front and back nonwoven fabric pieces in the general rectilinear rectangular upper pad shape of a soap-bar, with an opening present in the assembly for receiving and retaining the soap-bar between front and back nonwoven fabric pieces and a peripheral nonwoven fabric extending about and secured to the upper pad at the periphery thereof. It is contemplated that the front and/or back nonwoven fabric piece may comprise independently a plurality of coplanar nonwoven fabric subsections, each subsection oriented such that the recoverable extensibility is best utilized for conforming to the variety of shapes soap-bars available. It is further contemplated that the front and/or back nonwoven fabric piece may comprise independently a plurality of non-extensible coplanar nonwoven fabric subsections, each subsection adjoining an extensible nonwoven fabric section oriented such that the recoverable extensibility is best utilized for conforming to the variety of shapes soap-bars available. Suitable non-extensible coplanar nonwoven fabric subsections include those nonwoven fabrics having multi-planar or nubbed profiles.
[0055] Means for securing the opening in the soap-bar cover assembly include, but are not limited to, mechanical closures such as snaps, buttons, and hook-and-loop fasteners, as well as, interleaving or coordinating folds of the nonwoven fabric.
[0056] To further enhance the ability of a soap-bar to drain excess water during periods of non-use, and thus reduce deleterious physical deteriorate of the soap-bar, various means may be employed. Such mean include, but are not limited to, eyelettes, hooks, straps and ropes which are formed in the soap-bar cover and utilize external apparati which engage said eyelettes, hooks, straps, and ropes. Further, as the soap-bar cover fabric is fibrous, a loop from a “hook-and-loop” fastener can be utilized to directly engage any region of the soap-bar cover.
[0057] From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiment illustrated herein 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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The present invention is directed to a soap-bar cover comprising a water-permeable fabric, and particularly a soap-bar cover exhibiting a stretch and recovery performance while maintaining a substantially planar surface. Soap-bar covers fabricated in accordance with the present invention are particularly useful as a means for enhancing the cleansing properties of commercially available soap-bar products. The soap-bar cover is composed of a woven or nonwoven fabric exhibiting stretch and recovery properties. Use of a stretch and recovery fabric in the soap-bar cover allows for the cover to conform to the contours of the soap-bar and is thus able to adjust to a wide variety of soap-bar profiles including cubic and ovoid.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of producing a muffler for use with an internal combustion engine or the like which comprises an assembly of plates and tubes rigidly connected together and, more particularly, to a method which forms an eyelet in a predetermined location of a plate and inserts a tube thereinto to set up rigid connection therebetween.
2. Description of the Prior Art
A prior art muffler for an internal combustion engine or the like includes end walls which define axially opposite ends of a cylindrical casing. The interior of the casing is divided into a plurality of chambers by partition walls. Various tubes extend along the axis of the casing into, out of and within the casing while being supported by the various walls. Typical examples of the techniques heretofore employed to rigidly connect the plates and tubes may be spot welding and arc welding. However, a muffler manufactured by such a method is susceptive to corrosion due to the influence of heat. In light of this, Japanese Patent Publication No. 57-3805/82 and the parallel U.S. Pat. No. 3,921,754 issued Nov. 25, 1975, disclose a procedure in which a tube mounted in a plate is pressed from the opposite sides along its axis to form bulges at opposite sides of the plate and, then, the bulges are crimped to set up a rigid assembly of the tube and plate. A problem has existed in this method in that the tube has to be supported by a special metal core to be thereby prevented from being collapsed radially inwardly, resulting in an increase in cost and intricate assembling work.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to eliminate the drawbacks inherent in the prior art methods of producing a muffler for an internal combustion engine or the like as described above.
It is another object of the present invention to provide a method of producing a muffler for an internal combustion engine or the like which insures rigid connection of a plate and a tube while increasing the strength of the assembly against heat.
It is another object of the present invention to provide a method of producing a muffler for an internal combustion engine or the like which promotes economical production of the muffler by means of a simple device and convenient work.
It is another object of the present invention to provide a method which allows a plate and a tube to be firmly connected together by inserting the tube into an eyelet formed through the plate.
A method of rigidly connecting at least one plate and at least one tube to each other embodying the present invention includes the step of forming an eyelet through the plate such that a flange is produced which has an inside diameter substantially equal to the outside diameter of the tube. The tube is inserted into the eyelet and fixed in a predetermined position relative to the plate. Crimping means is prepared for crimping the flange of the plate and which is formed with a recess having an inside diameter substantially equal to the outside diameter of the tube. The crimping means is positioned relative to the tube through the recess. Then, the crimping means is driven until the flange of the tube becomes deformed to thrust into the outer periphery of the tube.
In accordance with the present invention, a method of rigidly connecting a plate and a tube such as those of a muffler associated with an internal combustion engine is disclosed. The plate is formed with an eyelet by burring or like technique and, then, the tube is inserted into the eyelet as far as a predetermined position. A stop is placed to back up the plate at a flat surface of the latter where a flange produced by the eyelet is absent. This is followed by driving a die to compress the flange in such a manner as to reduce the diameter of the eyelet, thereby plastically deforming the flange. Part of the flange proportional to the decrease in diameter is caused to bite the periphery of the tube.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the present invention will become more apparent from a consideration of the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a sectional side elevation of a muffler produced by the method of the present invention;
FIGS. 2a-2d are fragmentary sections showing a procedure for connecting a plate and a tube in accordance with the present invention;
FIG. 3 is a section of a modified form of a flange formed in a plate which is connected to a tube in accordance with the present invention;
FIGS. 4a and 4b are fragmentary sections showing another example of the method of the present invention;
FIGS. 5a-5d are fragmentary sections showing a third example of the method of the present invention;
FIG. 6 is a framentary section of another possible form of a die applicable to the present invention;
FIG. 7 is a framentary section showing a plurality of tubes rigidly connected to a single plate in accordance with the present invention;
FIG. 8 is a fragmentary section showing a single tube connected to a plurality of adjacent plates in accordance with the present invention; and
FIG. 9 is a fragmentary section showing a plurality of tubes connected to a plurality of adjacent plates in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, a muffler produced by the method of the present invention is shown and generally designated by the reference numeral 10. The muffler 10 comprises a hollow cylindrical member or casing 12 whose opposite ends are closed by end walls 14 and 14' respectively. The interior of the casing 12 is divided into three chambers A, B and C by partition walls 16 and 16'. An exhaust pipe 18 extends into the chamber A through the end wall 14. The chambers B and C are intercommunicated by a tube 20 which extends through the partition 16'. The chamber B is communicated to the outside of the casing 16' by a tube 20' which extends through the partition 16' and end wall 14'. Further, the chambers A and C are intercommunicated by a tube 20" which extends through the partition 16 and 16'.
A procedure for assembling the muffler 10 is illustrated in FIG. 2. In the drawing, a plate 22 represents the end walls and partition walls of the muffler 10 and a tube 24, the exhaust pipe and tubes. The plate 22 is formed with an eyelet 22a by burring which has an inside diameter substantially equal to the outside diameter of the tube 24 (FIG. 2a). The tube 24 is inserted into the eyelet 22a as far as a predetermined position (FIG. 2b). A stop or backup 26 is coupled over the tube 24 to contact a flat surface of the plate 22 where a flange 28 is absent and, then, a die 30 is actuated to press the flange 28 along the axis of the tube 24 which has been backed up by the stop 26 (FIG. 2c). The flange 28 has its distal end engaged in an annular recess 30b formed in the end 30a of the die 30, thereby being plastically turned down to the shape shown in FIG. 2d.
While the flange 28 undergoes progressive deformation due to the coacting stop 26 and die 30, it is prevented from collapsing from the distal end inasmuch as the distal end is engaged in the recess 30b of the die 30. It will be apparent that the flange 28 thrusts deeper into the periphery of the tube 24 in proportion to the mechanical strength of the tube 24 against deformation. The flange 28, as one may fear, is apt to wedge into the gap between the outer periphery of the tube 24 and the inner periphery of the die 30. This aptitude may be eliminated using the arrangement shown in FIG. 3 wherein the recess 30b of the die 30 has a depth larger than the thickness of the flange 28 or plate 22 and the distal end of the flange 28 is flared outwardly away from the tube 24.
Referring to FIGS. 4a and 4b, a plate and tube assembly prepared by another example of the method of the present invention is shown. A stop 32 has an annular frustoconical recess 32a and a die 34, an annular frustoconical recess 34a. As the die 34 is driven toward the stop 32 to compress the flange 28, the flange 28 is partly urged in a direction for reducing the diameter of the eyelet 22a so that a fragment thereof proportional to the decrease in eyelet diameter bites the tube 24 to set up rigid connection between the plate 22 and the tube 24, as illustrated in FIG. 4b.
Referring to FIGS. 5a-5d, a plate and tube assembly attainable with a third example of the method of the present invention is shown. The eyelet 22a is so formed in the plate 22 as to produce a relatively shallow flange 28. A die 36 is driven toward a stop 38 to press the flange 28 until the flange 28 becomes flush with the rest of the plate 22 while thrusting into the tube 24. In detail, the plate 22 is burred to have an eyelet 22a whose inside diameter is substantially equal to the outside diameter of the tube 24 (FIG. 5a) and, then, the tube 24 is fit in the eyelet 22a to a predetermined position (FIG. 5b). Alternatively, the inside diameter of the eyelet 22a may be designed slightly smaller than the outside diameter of the tube 24 in order to press fit the tube 24 into the eyelet 22a such that the diameter of the eyelet 22a is enlarged. As in the foregoing embodiments, the die 36 having a flat work surface is driven toward the stop 38 which backs up the plate 22, thereby compressing the flange 28 along the axis of the tube 24 (FIG. 5c). This deforms the flange 28 until the latter becomes coplanar with the rest of the plate 22. The resulting decrease in the diameter of the eyelet 22a drives the annular edge of the eyelet 22a into the tube 24 to firmly connect the tube 24 to the plate 22 (FIG. 5d).
It will be noted that the die 30, 34 or 36 may compress the flange 28 over the entire circumference of the eyelet 22a or only part thereof, e.g., at several spaced locations along the circumference.
As shown in FIG. 6, the die 30 may be made up of a radially inner member 30a for pressing the deformable flange 28 of the plate 22 against the stop 26 and a radially outer member 30b for retaining a non-deformable section 22b of the plate 22 in cooperation with the stop 26. Such a die assembly will successfully prevent the flat plate section 22b from being deformed and is applicable to the other dies 34 and 36 as well.
As shown in FIG. 7, a plurality of tubes 24 and 24' may be mounted at the same time in a single plate 22. The tubes 24 and 24' are respectively inserted into eyelets 22a and 22a' which are formed through the plate 22. A die 40 compresses the tubes 24 and 24' against a common backup or stop 42 until flanges 26 and 26' of the tubes become plastically deformed to firmly connect the tubes to the plate.
Where it is desired to attach a single tube 24 to a plurality of adjacent plates 22 and 22', a stop 44 is placed between the plates 22 and 22' as shown in FIG. 8 such that its opposite ends back up the adjacent surfaces of the plates 22 and 22'. Dies 46 and 46' are moved toward the plates 22 and 22' from opposite sides of the stop 44 to secure the tube 24 to both the plates 22 and 22'.
Furthermore, a plurality of plates 22 and 22' and a plurality of tubes 24, 24' and 24" may be assembled at the same time in the manner shown in FIG. 9. A stop 48 is interposed between the adjacent plates 22 and 22' to back them up as dies 50 and 50' compress adjacent flanges from opposite sides of the stop 48.
In summary, it will be seen that the present invention provides a method which simply yet firmly connects various tubes of a muffler to various wall members. Because the tubes are prevented from collapsing radially inwardly without the need for any metal core or the like, the muffler can be assembled quite easily and is suitable for economical production on quantiry basis.
Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.
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A method of rigidly connecting a plate and a tube such as those of a muffler associated with an internal combustion engine. The plate is formed with an eyelet by burring or like technique and, then, the tube is inserted into the eyelet as far as a predetermined position. A stop is placed to backup the plate at a flat surface of the latter where a flange produced by the eyelet is absent. This is followed by driving a die to compress the flange in such a manner as to reduce the diameter of the eyelet, thereby plastically deforming the flange. Part of the flange proportional to the decrease in diameter is caused to thrust into the periphery of the tube.
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FIELD OF INVENTION
This invention relates to liquid crystal compositions and to electro-optical devices which modulate light. More particularly, the invention relates to the use of certain additives to liquid crystal compositions to enhance their dynamic scattering properties.
BACKGROUND OF INVENTION
Liquid crystal compositions are used in various electro-optical devices which involve the modulation of electromagnetic radiation, such as light valves and transmissive or reflective optical display devices. Such light valves are controlled by an electric field and operate when the nematic liquid crystal material is in its mesomorphic state.
Mesomorphism has been described as a state of matter with molecular order between that of a crystalline solid and a normal liquid. Crystalline solids are characterized by a non-random distribution of the molecules and a three-dimensional order in the location of the individual molecules within the crystal lattice. Normal liquids generally show isotropic behavior, for example, to light, due to the fact that the molecules of the liquid are randomly oriented.
In the mesomorphic state or mesophase of liquid crystal compositions, which are comprised of rod-shaped molecules, the directional arrangement of at least a part of the molecules is non-random. Among the various types of liquid crystal compositions, nematic liquid crystals are characterized by the fact that the long axes of the molecules maintain a parallel or nearly parallel arrangement to each other such that a one-dimensional order exists. Nematic liquid crystal compositions are usually characterized by a turbid appearance.
The mesophases of liquid crystal compositions exist over a temperature range which is dependent on the specific nature of the composition and molecular structure. Below this range the compositions become crystalline solids and above this range, the preferred directional alignment of the molecules is destroyed and a normal liquid having isotropic behavior results. Both of these phase changes are characterized by sharp transition points.
In the mesomorphic state, the anisotropic properties of the individual molecules are conferred upon the bulk material. In regard to dielectric properties, the dielectric constant (ε.sub.∥ ) parallel to the long axis of the molecules can be larger or smaller than the dielectric constant (ε.sub.| ) perpendicular to the long axis of the molecules. If ε.sub.∥ is greater than ε.sub.| , such that ε.sub.∥ - ε.sub.| > 0 or ε.sub.∥/ε.sub.| > 1, then the composition in question is said to have a positive dielectric anisotropy. On the other hand, if ε.sub.∥ is less than ε.sub.| , such that ε.sub.∥ - ε.sub.| < 0 or ε.sub.∥/ε.sub.| < 1, then the composition is said to have a negative dielectric anisotropy.
This dielectric anisotropy is responsible in part for the utility of liquid crystalline compounds in various electrooptical devices which involve the modulation of light, such as light valves and optical display devices. Such light valves typically are controlled by an electric field and operate when the liquid crystalline material is in its mesomorphic state.
The anisotropic molecules can be aligned perpendicularly or uniaxially parallel to a surface giving a transparent appearance, and when an external magnetic of electric field above a threshold value is applied perpendicular to the surface, molecules with a negative dielectric anisotropy tend to orient perpendicularly to this field. However, this orientation is impeded by the presence of ions moving in the field which cause constant movement of the liquid crystal molecules (these molecules behaving as groups about 10 - 5 cm. in size) which is a dynamic state resulting in the scattering of light. Thus, the application of an electric or magnetic field brings about a change from a relatively transparent optical state to a translucent dynamic scattering state.
From Helfrich's theory [J. Chem. Phys., 51, 4092 (1969)] of the threshold voltage for the onset of electrohydrodynamic instabilities in liquid crystals the following criteria are extracted: ##EQU1## for the electric field applied perpendicular to the long axis of the liquid crystalline molecules and ##EQU2## for the electric field applied parallel to the long axis of the molecules. In expressions I and II above, σ refers to the conductivity and the subscripts ∥ and ⊥ refer to the component of the anisotropic material parameter relative to the direction of axis of preferred molecular interaction as used previously in connection with the dielectric constant. In order to create electrodynamic instabilities in a liquid crystalline material so as to result in intensive turbulence with concomitant high light scattering (dynamic scattering), the anisotropies of σ and ε have to fulfill the above relations in which C accounts for the viscosity anisotropy.
Liquid crystalline materials with a negative dielectric anisotropy (ε.sub.∥/ε.sub.| < 1) will be oriented with the long axis perpendicular to the applied field and relation I above applies. On the other hand, materials with a positive dielectric anisotropy (ε.sub.∥/ε.sub.| < 1) will be oriented with the long axis parallel to the applied field and relation II applies. However, relation II requires that σ.sub.∥/σ.sub.| > 1 which is rarely ever observed in liquid crystalline materials. Thus, materials having a positive dielectric anisotropy are generally unsuited for dynamic scattering applications.
Of all liquid crystalline materials having a negative dielectric anisotropy, some are better suited than others for use in dynamic scattering applications and some are not useful at all because, for example, the magnitude of Δε relative to Δσ is not appropriate. Accordingly, there is a need in the art for a means of rendering nematic liquid crystalline materials having a negative dielectric anisotropy suitable for dynamic scattering.
SUMMARY OF THE INVENTION
We have found that many nematic liquid crystals having a negative dielectric anisotropy, but which do not exhibit dynamic scattering can be rendered suitable for dynamic scattering applications by the addition of certain organic dopants. Also, these dopants can improve the scattering ability of other nematic liquid crystals such as those which already exhibit some degree of scattering but which have threshold voltages which are too high for practical applications. Thus, the addition of the described dopants results in a lowering of the threshold voltage required for dynamic scattering.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic sectional view of an electro-optical display device.
FIG. 2 is a graph of scattered light intensity versus applied voltage for a cell of this invention and for a control.
DESCRIPTION OF PREFERRED EMBODIMENT
The objects and advantages of this invention are provided through the addition of certain organic salts to nematic liquid crystals having a negative dielectric anisotropy.
The organic salts useful in accordance with the present invention include metal or ammonium salts of an organic carboxylate or an organic sulfonate. In particular, the anion of these salts should have the formula:
RX -
wherein X - is a sulfonate (-SO 3 - ) or a carboxylate (-COO - ) group and R is (1) an electronegatively substituted alkyl group having about 1 to 10 carbon atoms or (2) a phenyl or naphthyl group including substituted phenyl or naphthyl having at least one substituent selected from an alkyl group having about 1 to 10 carbon atoms (e.g., ethyl, methyl, isopropyl, butyl, octyl, decyl), a halogen atom (e.g., chloro, bromo, fluoro), a nitro group, a cyano group, an alkylsulfonyl group typically having about 1 to 4 carbon atoms, and the like. Preferred anions are benzoate or benzenesulfonate ions of the formula:
R'CO 2 - or R"SO 3 -
wherein R' represents (a) a substituted phenyl group having at least one electronegative substituent such as a halogen atom, a nitro group, a cyano group, an alkylsulfonyl group as above, and the like or (b) a naphthyl group including (c) a naphthyl group having at least one electronegative substituent as described above for (a); and R" represents the groups described for R' above as well as a phenyl or naphthyl group having as a substituent at least one alkyl group having 1 to 10 carbon atoms. "Electronegatively substituted alkyl group" as used herein, has reference to an alkyl group of about 1 to 10 carbon atoms, which has as a substituent on at least the α or β carbon atoms at least one electron-withdrawing group such as a halogen atom (e.g., fluorine, chlorine), a nitro group, a cyano group, an alkylsulfonyl group (i.e., -SO 2 R in which R represents an alkyl group having 1 to about 4 carbon atoms) and the like. Similarly, "electronegative substituent" has reference to an electron-withdrawing group as described above. For a further discussion of electronegativity, reference is made to J. Hine, "Physical Organic Chemistry", 2nd ed., pp. 5 et.seq. and 32 et.seq., McGraw-Hill Book Company, Inc., New York, 1962, or to L. Pauling, "The Nature of the Chemical Bond", 3rd ed., pp. 85-105, Cornell University Press, Ithaca, New York, 1960.
The cation of the present salts appears to have little significant influence on the conductivity anisotropy. The cations, in general, are of larger size than the anion and aid the solubility of the salt in the liquid crystal composition. This solubility is brought about by the presence of one or more long chain paraffinic substituents (e.g., about 8 to 24 carbon atoms). These paraffinic substituents render the present salts soluble in the liquid crystal compositions at the concentrations of use. Typical useful cations are metal, ammonium or organic ammonium derivatives such as those of the formula:
(R'") 4 N +
wherein (a) each R'" is an alkyl group of about 1 to 24 carbon atoms, with the total carbon atom content of all four R'"groups being at least about 11 carbon atoms, or (b) any three of R'" can be taken together to represent the atoms (preferably carbon atoms) necessary to complete a 6- to 10-membered heterocyclic nucleus, including such substituted nuclei, for example, pyridinium, quinolinium, isoquinolinium, 2-(2-quinolylidenemethyl)quinolinium, and the like with the fourth R'" representing an alkyl group of about 8 to 24 carbon atoms. Included among preferred cations from the standpoint of availability and non-interfering properties are those having the formula:
(C.sub.n H.sub.2n.sub.+1).sub.y (CH.sub.3).sub.4.sub.-y N.sup.+
where n is an integer having a value of 4 to about 20 and y is an integer having a value of 1 to 4. As mentioned above, the cation has very little, if any, effect on the conductivity anisotropy. Thus, in accordance with this invention, the cation can be selected from a variety of metal, ammonium or organic ammonium cations which are soluble in the liquid crystalline composition of choice. Particularly useful is the dimethyldioctadecyl ammonium cation. Other cations useful in the formation of dopants of this invention include pyridinium, quinolinium and cyanine dye cations having, respectively, the following structures: ##SPC1## wherein n is as described above and m is an integer having a value of about 0 to 2.
The amount of dopant which must be added to achieve the desired effect can vary depending on the conductivity desired. In a preferred embodiment, nearly all of the conductivity arises from the dopant. Thus, the liquid crystals used are preferably in a highly pure state having as high a resistivity value as possible. An effective amount of the organic salt dopant will increase the positive conductivity anisotropy of the liquid crystal composition as well as the absolute conductivity. A typical concentration of dopant is 10 - 3 or less mole of dopant per average mole of liquid crystalline composition. "Average mole" as used herein is based on the average molecular weight of a give composition which may contain more than one liquid crystalline compound. Preferred concentrations typically are in the range of about 10 - 4 to 10 - 7 mole of dopant per average mole of liquid crystalline composition.
The liquid crystalline materials which can be usefully doped with the additives of the present invention include a wide variety of nematic liquid crystals having a negative dielectric anisotropy. From the standpoint of ease of handling, preferred materials are those having a broad mesophase. However, materials exhibiting a nematic mesophase in a very narrow temperature range are also useful, but may require special handling such as costly temperature control means. Among the numerous nematic compounds having a negative dielectric anisotropy or useful in forming liquid crystal mixtures having a negative dielectric anisotropy are p-anisylidene-p'-aminophenyl acetate, p-n-butoxybenzylidene-p'-aminophenyl acetate, p-n-octylbenzylidene-p'-aminophenyl acetate, N-(p-methoxybenzylidene)-p-butylaniline (MBBA), butyl-p-(p-ethoxyphenoxycarbonyl)phenyl carbonate, p-[N-(p-methoxybenzylidene)amino]phenyl acetate, p-[(p-methoxybenzylidene)amino]phenyl benzoate, ethoxybenzylidene-p-butylaniline (EBBA), 4-n-alkyl-4'-ethoxy-α-chloro-trans-stilbenes having from about 1 to about 10 carbon atoms in the alkyl moiety, p-n-anisylidene-p'-aminophenyl butyrate, p-n-butoxybenzylidene-p'-aminophenyl pentanoate. In addition, mixtures such as eutectic mixtures of nematic compounds can be used, for example, MBBA and EBBA or mixtures of N-(p-valeryloxybenzylidene)-p-pentoxycarbonyloxyaniline and N-(p-acetoxybenzylidene)-p-methoxycarbonyloxyaniline, and other similar mixtures as described in Klanderman and Klingbiel U.S. application Ser. No. 415,197, filed Nov. 12, 1973, and entitled NEMATIC LIQUID CRYSTAL COMPOSITIONS (incorporated herein by reference). A great number of useful nematic compounds having a negative dielectric anisotropy are well known in the literature.
Previously, there have been suggestions of adding so-called conductivity agents to liquid crystal compositions. Such agents, as described, for example, in U.S. Pat. Nos. 3,499,112 and 3,656,834, are typically comprised of a simple, inorganic anion such as bromide, chloride, iodide or nitrate. While these prior agents are useful in effecting the absolute conductivity of a given liquid crystal composition, those same agents have no meaningful effect on the conductivity anisotropy of that composition. However, the particular anions of the ionic dopants of the present invention have a significant effect on the conductivity anisotropy which often results in a noticeable reduction of the threshold voltage needed for the onset of electro-hydrodynamic instabilities as well as in a reduction of the voltage required to produce dynamic scattering.
The doped nematic liquid crystalline compositions of this invention are useful in electro-optical display devices. A typical cell used in forming electro-optical devices is analogous to a parallel plate capacitor containing a liquid crystalline material with negative dielectric anisotropy as the dielectric. The plates are conductive and at least one of the plates is transparent. When no potential is applied across the two plates or walls, the cell appears substantially transparent. Upon the application of a d.c. or low frequency a.c. signal across the plates, the liquid crystalline material typically turns milky white. This white or cloudy condition is referred to as a scattering mode. In many scattering electro-optical cells, the cell becomes substantially transparent again when the voltage is removed.
FIG. 1 illustrates an optical display device 9 comprised of transparent cell walls 10 and 11 which are conductive, typically having a conductive layer 12 and 13 of, for example, indium oxide on the inner surfaces thereof. The walls 10 and 11 are usually spaced apart a distance d typically in the range of about 2 to about 250 microns with best results usually being obtained with a spacing of about 3 to about 100 microns. Liquid crystalline material 17 is contained within cell walls 10 and 11.
The layer of liquid crystalline material 17 is subjected to an electric field of sufficient magnitude to alter or modulate the light scattering properties of the layer. The light scattering property of material 17 is not affected until the electric field reaches a certain minimum threshold value. This value depends, of course, on the particular material or combination of materials being used, but is typically about 10 4 volts per centimeter of layer thickness. In order to subject the layer to an electric field, display device 9 includes a voltage source 15 for applying a suitable electrical potential across conductive layers 12 and 13. The potential applied can be direct voltage, including pulsed direct voltage, or low-frequency alternating voltage and typically has a value between about 4 V. and about 80 V.
Device 9 can optionally have a reflective coating 14 when used in the reflective mode. Light source 16 can be positioned on either side of device 9. Source 16 would be on the side of device 9 opposite the observer when used in the transmissive mode. If used in the reflective mode, source 16 is located on the same side as the observer and typically is positioned so that the incident light is directed as shown by arrow A. In the zero or ground state, light which is not transmitted is reflected at an angle equal to the angle of incidence as shown by arrow B. When a voltage is applied, say, 15 V., the cell is placed in the scattering mode and, therefore, the angle of reflected light now changes until it is essentially normal to the plane of cell 10 as shown by arrows C.
The cell configuration can be in the form of two spaced walls having thereon conductive strips with the strips of one wall being arranged orthogonal to those of the other wall to form an x-y grid. Each strip has a separate electrical connection to a voltage source. In this manner, a cross-conductor, addressable cell is formed which allows one to selectively apply the voltage necessary for dynamic scattering to any desired portion of the grid. By the use of suitable logic, solid-state electronic systems can be utilized to address a large scale cell of this type and display alphanumeric information.
Useful results have been obtained with salts of the following anions being employed as dopants according to the present invention:
A. Trifluoroacetate
B. Heptafluorobutyrate
C. Benzenesulfonate
D. p-Toluenesulfonate
E. p-Chlorobenzenesulfonate
F. 2-Chloro-5-nitrobenzenesulfonate
G. p-Nitrobenzenesulfonate
H. 2,5-Dichlorobenzenesulfonate
I. 2-Chloro-3,5-dinitrobenzenesulfonate
J. p-Bromobenzenesulfonate
K. 2-Chloro-5-methylbenzenesulfonate
L. 2,5-Dimethylbenzenesulfonate
M. 2-Methyl-5-nitrobenzenesulfonate
N. 2-Naphthalenesulfonate
O. Pentafluorobenzoate Doping of liquid crystals in accordance with the process of this invention is accomplished by directly mixing the dopant with the liquid crystal composition in a ratio of about 1 × 10 - 4 to 1 × 10 - 7 mole of dopant per mole (average) of liquid crystal composition and agitating, for example, in an ultrasonic agitator, at a temperature of between about 20° to 100°C, preferably about 50°C, for a period of about 15 minutes to about 3 hours, preferably about 1 hour. The properties of representative liquid crystal compositions doped in accordance with this invention are described in the following Table I in which the salts are dimethyldioctadecylammonium salts of the anion designated under "Dopant". "Dopant P" is a control in which the anion is perchlorate (not part of this invention). The liquid crystal (LC) compositions are (I) the nine component equilibrated mixtures formed by combining a mixture of 2 molar parts of p[(p-methoxybenzylidene)amino]phenyl butyrate, 1 molar part of p[(p-butoxybenzylidene)amino]phenyl propionate and 1 molar part of N-(p-valeryloxybenzylidene)-p-pentoxycarbonyloxyaniline with about 1/2 percent by weight of an acidic transiminization catalyst and heating at 80°C for four hours, as in Example 1 of U.S. Ser. No. 415,197, referred to above; (II) a 2:1 by weight mixture of N-(p-valeryloxybenzylidene)-p-pentoxycarbonyloxyaniline and N-(p-acetoxybenzylidene)-p-methoxycarbonyloxyaniline; (III) composition "G" of Table II, Column 8 of J. E. Goldmacher et al, U.S. Pat. No. 3,540,796, purified to remove all catalyst; and (IV) N-(p-methoxybenzylidene)-p-butylaniline also referred to as MBBA.
Table I__________________________________________________________________________ Mole Dopant Liquid perSample Crystal Mole LiquidNo. Composition Dopant Crystal Comp. σ∥/σ⊥ σ*__________________________________________________________________________1 IV B 4×10.sup.-.sup.5 1.40 7.322 IV C " 1.44 4.523 IV D " 1.50 1.534 IV E " 1.46 3.225 IV F " 1.50 5.526 IV G " 1.46 3.637 IV H 4×10.sup.-.sup.5 1.46 7.188 IV I " 1.63 22.09 IV J " 1.54 4.0910 IV K " 1.54 4.2911 IV L " 1.55 4.2412 IV M " 1.51 9.6913 IV N 4×10.sup.-.sup.5 1.58 3.3414 IV O " 1.79 11.715 IV P** 1×10.sup.-.sup.4 1.23 5016 II E 4×10.sup..sup.-5 1.22 4.8917 II G " 1.24 7.7218 II G " 1.20 4.9019 I I " 1.96 2920 I L " 1.92 1221 I N " 2.04 1222 I O " 2.1 1923 I P** " 1.15 3824 III D 1×10.sup.-.sup.4 1.59 5025 III P** 1×10.sup..sup.-4 1.15 50__________________________________________________________________________ *σ = Bulk Conductivity × 10.sup.-.sup.10 ohm.sup.-.sup.1 cm.sup.-.sup.1 = [(σ∥+2σ⊥)/3]10.sup..sup.-10 ohm.sup.-.sup.1 cm.sup.-.sup.1 **Control
The following examples are included for a further understanding of the invention. In these examples, the electrical potentials are applied to the liquid crystalline compositions using a cell arrangement similar to that shown in FIG. 1.
EXAMPLE 1
To the nematic liquid crystal III above, composed of the three compounds: ##SPC2##
in equal parts is added the perchlorate salt of the "cyanine dye" compound of formula 3 on page 8 in which n = 18 and m = 0 until a 10 - 4 molar solution of the salt is reached. The doped mixture has a conductivity σ ≈ 5 × 10 - 9 Ω - 1 cm - 1 and σ.sub.∥ /σ.sub.| = 1.15. This mixture does not exhibit dynamic scattering (D.S.) upon application of voltage up to 50 V rms as is predicted from calculations using relationship (I) above. That relationship, together with the material parameters ε.sub.∥/ε.sub.|= 0.75 and c ≈0.5, shows that a ε.sub.∥/ε.sub.| > 1.25 is needed in order for dynamic scattering to occur. To the same liquid crystal composition III (i.e., the three nematic materials shown above) is added a 10 - 4 molar of the p-toluenesulfonate salt of the above "cyanine dye" which yields a conductive mixture having σ ≈ 5 × 10 - 9 Ω - 1 cm - 1 and σ.sub.∥/σ.sub.| = 1.59. The composition having this σ.sub.∥/σ.sub.| produces intense dynamic scattering upon the application of only 15 V rms .
EXAMPLE 2
A portion of the nematic mixture I above is doped to 4 × 10 - 5 molar concentration with (1) a control of dioctadecyldimethyl perchlorate, and a second portion of mixture I is similarly doped with (2) dioctadecyldimethyl-2-chloro-3,5-dinitrobenzenesulfonate. The bulk conductivity of both compositions is greater than 2 × 10 - 9 ohm - 1 cm - 1 and high enough above the critical conductivity necessary to produce dynamic scattering under 60 Hz excitation. The conductivity anisotropy σ.sub.∥/σ.sub.| , the threshold voltage (V th ) for the onset of electro-hydrodynamic instabilities and the voltage required to produce dynamic scattering (V DS ) of the same intensity at an angle of 30° off-axis are as follows (compare FIG. 2):Dopant σ∥/σ⊥ V th V DS ______________________________________1 1.15 - 1.23 22.5 ˜452 1.98 5.25 ˜20______________________________________
The above data demonstrate that the higher the conductivity anisotropy, the lower the voltage required to produce electrohydrodynamic instabilities and dynamic scattering. The data further illustrate that p-toluenesulfonate salts of the invention have a larger σ.sub.∥/σ.sub.| than perchlorate salts. The liquid crystal material employed in this example is of the Schiff-base type. However, the significant difference between the anions of this invention and prior art anions also holds for nematic materials of different chemical composition. A similar composition of liquid crystal mixture I above doped with dimethyloctadecylammonium 2-chloro-5-nitrobenzenesulfonate gives a composition having σ.sub.∥/σ.sub.| = 1.56 and a σ of 16.5.
EXAMPLE 3
The following mixtures of various liquid crystals (L.C.) with the dopant (1) dimethyloctadecylammonium p-toluenesulfonate or the control (2) dimethyloctadecylammonium perchlorate give the conductivity anisotropy (σ.sub.∥/σ.sub.| ) values shown in Table II.
Table II______________________________________Dopant Liquid Crystal σ∥/σ⊥______________________________________2 4'-Ethoxy-4-butyl-α-chlorostilbene 1.36(control)1 " 1.582 p-Pentylphenol-p-methoxy benzoate ester 1.23(control)1 " 1.482 N-(p-methoxybenzylidene)-p-butylaniline 1.22(control)1 " 1.48______________________________________
These data demonstrate the increased conductivity anisotropy obtained with the salts of this invention.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
|
Dynamic scattering of nematic liquid crystalline compositions is enhanced by the addition of minor amounts of soluble salts having an organic carboxylate or organic sulfonate anion. The addition of these salts results in a lowering of the operating voltages necessary to obtain dynamic scattering.
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TECHNICAL FIELD
[0001] This invention relates in general to facilitating a call session between a wireless phone and a remote phone, and more particularly to avoiding call drop for the call session.
BACKGROUND
[0002] Traditionally, when a user is using a wireless phone to participate in a phone call session with a remote peer phone, the radio signal associated with the wireless phone can sometimes be lost due to radio interference or movement of the user. As a result, the signaling and payload communication between the wireless phone and the remote peer phone is lost, resulting in the phone call session being dropped. In order to reestablish the call session, a user is required to redial the phone number of the other phone.
SUMMARY
[0003] In accordance with one embodiment of the present invention, there is provided a method for facilitating a call session including receiving a request to establish a call session between a wireless phone and a remote phone, and establishing a call session between the wireless phone and the remote phone. The call session includes a first connection with the wireless phone and a second connection with the remote phone. The method further includes monitoring the first connection to determine if there is a connection loss of the first connection, and determining that there is a connection loss of the first connection. In response to determining that there is a connection loss of the first connection, the method further includes holding the second connection with the remote phone, attempting to reestablish the first connection with the wireless phone, and resuming the call session in response to the first connection being reestablished.
[0004] In accordance with another embodiment of the present invention, a system for facilitating a call session includes a wireless phone, a remote phone, and a call relay station. The call relay station is adapted to receive a request to establish a call session between the wireless phone and the remote phone, and establish a call session between the wireless phone and the remote phone. The call session includes a first connection with the wireless phone and a second connection with the remote phone. The call relay station is further adapted to monitor the first connection to determine if there is a connection loss of the first connection, and determine that there is a connection loss of the first connection. In response to determining that there is a connection loss of the first connection, the call relay station is further adapted to hold the second connection with the remote phone, attempt to reestablish the first connection with the wireless phone, and resume the call session in response to the first connection being reestablished.
[0005] An advantage of certain embodiments of the present invention is that call drop due to temporary loss of a radio signal when using a wireless phone can be avoided.
[0006] Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, descriptions, and claims. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] For a more complete understanding of the present invention and its advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
[0008] FIG. 1 is a block diagram of a system for avoiding call drop in accordance with an embodiment of the present invention;
[0009] FIG. 2 is a flow diagram of a process for avoiding call drop using a call relay station in accordance with an embodiment of the present invention;
[0010] FIG. 3 is a signaling diagram of a process for avoiding call drop in accordance with an embodiment of the present invention; and
[0011] FIG. 4 is a block diagram of another system for avoiding call drop in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0012] In accordance with some embodiments of the invention, a wireless phone, such as, for example, a wireless (802.11) Internet Protocol (IP) phone or mobile phone, is assigned to a call relay station, preferably in geographic proximity to the wireless phone, to avoid call drop due to temporary loss of the radio signal associated with the wireless phone. The system finds a reliable call relay station to which to assign the wireless phone. During a call session between the wireless phone and a remote peer phone, the call relay station continuously monitors the connection to the wireless phone, holds or parks the call session if the connection to the wireless phone is dropped due to loss of the radio signal, and resumes the call session when the connection is re-established. This allows a call session to be reestablished without requiring a user to redial the phone number associated with the other phone in the call session.
[0013] FIG. 1 is a block diagram of a system 100 for avoiding call drop in accordance with an embodiment of the present invention. The system 100 includes a wireless phone 105 having a wireless connection to a call relay station 110 . The wireless phone 105 is assigned to the call relay station 110 during call setup. In at least one embodiment, wireless phone 105 may include a wireless Internet Protocol (IP) phone or a mobile phone. In at least one embodiment of the invention, the call relay station 110 is located in geographical proximity to the wireless phone 105 . In some embodiments of the invention, the call relay station 110 can be a router or gateway.
[0014] The system 100 further includes a remote peer phone 115 coupled to the call relay station 110 . In accordance with various embodiments of the invention, the remote peer phone 115 is coupled to the call relay station 110 through a reliable connection such as a wireline or mostly wireline connection. Accordingly, communication between the call relay station 110 and the remote peer phone 115 is not affected by the radio signal to the wireless phone 105 . In accordance with one embodiment, the connection of the remote peer phone 115 to the call relay station 110 is through a public switched telephone network (PSTN) and/or packet switched network.
[0015] In some embodiments, a request to establish a call session between the remote peer phone 115 and the wireless phone 105 is sent by the remote peer phone 115 to the call relay station 110 . In at least one embodiment, the request is initiated by a user of the remote peer phone 115 dialing a telephone number associated with the wireless phone 105 . In response to the request to establish the call session, the call relay station 110 establishes a first call connection to the remote peer phone 115 and a second call connection to the wireless phone 105 . During the call session, the call relay station 110 relays voice or other payload data between the wireless phone 105 and the remote peer phone 115 .
[0016] During the call session, the call relay station 110 continuously monitors the connection to the wireless phone 105 . If the connection is lost due to the loss of the radio signal, the call relay station 110 holds or parks the call so that the connection to the remote peer phone 115 is still active. In at least one embodiment, the call relay station 110 sends an announcement message to the remote peer phone 115 to initiate playing of the announcement message by the remote peer phone 115 to the user of the remote peer phone 115 to ask the user to hold the phone until the connection between the wireless phone 105 and the call relay station 120 is automatically reestablished. In addition, the wireless phone 105 may continuously play an announcement message to a user of the wireless phone 105 to hold and not hang up while the call relay station 110 attempts to reestablish the call connection with the wireless phone 105 .
[0017] After the connection is lost, the call relay station attempts to reestablish the call connection with the wireless phone 105 . The call relay station further includes a timer that is started when holding or parking the connection with the remote peer phone 115 upon loss of the connection to the wireless phone 105 . If after a predetermined time the connection to the wireless phone 105 has not been reestablished or the remote peer phone 115 hangs up, the call session is disconnected. When the timer expires before the connection to the wireless phone 105 can be reestablished, the call relay station 110 , may play an announcement message to notify the remote peer that the call session has been disconnected.
[0018] If the connection to the wireless phone 105 is reestablished before the timer expires, the call relay station 110 stops playing the announcement message to the remote peer phone 115 and restore relaying the payload between the wireless phone 105 and the remote peer phone 115 . At the same time, the wireless phone 105 also stops playing the hold announcement message to its user and restores the payload between itself and the call relay station 110 . As a result, the call session is reestablished between the wireless phone 105 and the remote peer phone 115 .
[0019] Although the foregoing embodiment describes a situation in the remote peer phone 115 initiates a call to the wireless phone 105 , it should be understood that in other embodiments, a call can be initiated by the wireless phone 105 .
[0020] In at least one embodiment, the user can selectively enable the assigning of the wireless phone 105 to the call relay station 110 to avoid call drop for an important incoming or outgoing call, and disable the assigning of the wireless phone 105 to the call relay station 110 for less important calls. In addition, in at least one embodiment, the user can choose to enable or disable the assigning of the wireless phone 105 to the call relay station 110 either before or after a call is connected. Accordingly, the user can have a choice to always assign the wireless phone 105 to the call relay station 110 for all incoming or outgoing calls, or the user can activate this feature on a call by call basis dependent upon his or her choice before or after the call is connected.
[0021] FIG. 2 is a flow diagram of a process 200 for avoiding call drop using a call relay station in accordance with an embodiment of the present invention. The process begins at a step 205 . In a step 210 , the call relay station 110 receives a call setup request from the remote peer phone 115 . In step 215 , the call relay station 110 sends a call connection message to the wireless phone 215 . In step 220 , a determination is made regarding whether a connection between the call relay station 110 and the wireless phone 105 has been established.
[0022] If it is determined in step 220 that the connection between the call relay station 110 and the wireless phone 105 has not been established, the call relay station 110 sends a busy signal to remote peer phone 115 in a step 225 . After step 225 , the call session is ended in a step 280 , and the process is stopped in a step 285 .
[0023] If it is determined in step 220 that the connection between the call relay station 110 and the wireless phone 105 has been established, the call relay station sends a call connect message to remote peer phone 115 in step 230 . In step 235 , a call session is established between the wireless phone 105 and the remote peer phone 115 . During the call session, the payload of the call session is relayed between the wireless phone 105 and the remote peer phone 115 by the call relay station 110 .
[0024] During the call session, the call relay station 110 monitors the connection with the wireless phone in a step 240 . In a step 245 , a determination is made in step 245 regarding whether there has been a hang up of the call by either the wireless phone 105 or the remote peer phone 115 . If it has been determined in step 245 that the call has been hung up, the process continues to step 280 in which the call session is ended. If it is determined in step 245 that the call has not been hung up, a determination is made in a step 250 regarding whether call payload has been lost between the wireless phone 105 and the call relay station 110 . Call payload loss between the wireless phone 105 and the call relay station 110 is indicative of connection loss between the wireless phone 105 and the call relay station 110 due to loss of the radio signal between the wireless phone 105 and the call relay station 110 .
[0025] If it is determined in step 250 that call payload has not been lost, the process returns to step 240 in which the connection between the call relay station 110 and the wireless phone 105 is monitored.
[0026] If it is determined in step 250 that call payload has been lost, the call relay station 110 assumes that the connection between the call relay station 110 and the wireless phone 105 has been lost, and the call relay station 110 holds the connection with the remote peer phone 115 in step 255 .
[0027] In step 260 , the call relay station 110 attempts to reestablish the connection with the wireless phone 105 . In step 265 , the call relay station 110 makes a determination regarding whether the connection with the wireless phone 105 has been established. If it is determined in step 265 that the connection has not been reestablished, the call relay station 110 determines if a timer indicative of a predetermined maximum allowable time for reestablished of the connection has expired in a step 270 . If it is determined in step 270 that the timer has not expired, the process returns to step 260 is which the call relay station 110 continues to attempt to reestablish the connection with the wireless phone 105 . If it is determined in step 270 , that the timer has expired, the process continues to step 280 in which the call session is ended.
[0028] If it is determined in step 265 that the connection has been reestablished, the call session resumes in step 275 . After reestablishment of the call session, the relaying of the payload of the call session between the wireless phone 105 and the remote peer phone 115 is resumed by the call relay station 110 . After resuming the call session in step 275 , the process returns to step 240 in which the call relay station 110 monitors the connection between the call relay station 110 and the wireless phone 105 .
[0029] In various embodiments of the invention, software embodied in a computer readable medium can comprise computer code such that when executed is operable to perform the steps described with respect to FIG. 2 .
[0030] FIG. 3 is a signaling diagram of a process 300 for avoiding call drop in accordance with an embodiment of the present invention. In the process 300 , the remote peer phone 115 sends a call setup request 305 to the call relay station 110 . The call setup request 305 includes a request to establish a call session with the wireless phone 105 . After receiving the call setup request 305 from the remote peer phone 115 , the call relay station establishes a connection 310 with the wireless phone 105 . After establishing the connection 310 with the wireless phone 105 , the call relay station establishes a connection 315 with the remote peer phone 115 .
[0031] After establishing the connection 315 with the remote peer phone 115 , the call relay station 110 establishes a call session 320 between the remote peer phone 115 and the wireless phone 105 in which payload between the remote peer phone 115 and the wireless phone 105 is relayed by the call relay station 110 .
[0032] In the embodiment illustrated in FIG. 3 , the call between the call relay station 110 and the wireless phone 105 is dropped such as from loss of the radio signal between the call relay station 110 and the wireless phone 105 . The call relay station 110 then sends a message 330 to the remote peer phone 115 to keep the connection alive between the remote peer phone 115 and the call relay station 110 . The call relay station 110 then reestablishes connection 335 with the wireless phone 105 , and the call session is resumed in step 340 .
[0033] FIG. 4 is a block diagram of another system 400 for avoiding call drop in accordance with an embodiment of the present invention. The system 400 includes a wireless phone 105 , a remote peer phone 115 and a first call relay station 110 a and a second call relay station 110 b . In accordance with the embodiment illustrated in FIG. 4 , the wireless phone 105 can be associated with either the first call relay station 110 a or the second call relay station 110 b . The call relay station 110 a and the call relay station 110 b operate in a similar manner to the call relay station 110 described with respect to FIGS. 1-3 except that the first call relay station 110 a and the second call relay station 110 b support roaming of the wireless phone 105 . In the system 400 of FIG. 4 , handoff of a call connection with wireless phone 105 between the first call relay station 110 a and the second call station 110 b is allowed.
[0034] For example, when a call is first established between the remote peer phone 115 and the wireless phone 105 , and the wireless phone 105 is in a geographical area serviced by the first call relay station 110 a , the wireless phone 105 is assigned to the first call relay station 110 a . Payload information associated with the call session between the wireless phone 105 and the remote peer phone 115 is relayed by the first call relay station 110 a . If the connection between the wireless phone 105 and the first call relay station 110 a is lost, the first call relay station 110 a attempts to reestablish the connection in the same or similar manner as the call relay station 110 described with respect to FIGS. 1-3 .
[0035] If the wireless phone 105 moves out of the geographical area serviced by the first call relay station 110 a , to the geographical area serviced by the second call relay station 110 b , the connection with the wireless phone 105 is handed-off from the first call relay station 110 a to the second call relay station 110 b . Payload information associated with the call session between the wireless phone 105 and the remote peer phone 115 is then relayed by the second call relay station 110 b . If the connection between the wireless phone 105 and the second call relay station 110 b is lost, the second call relay station 110 b attempts to reestablish the connection in the same or similar manner as the call relay station 110 described with respect to FIGS. 1-3 .
[0036] An example application of the principles of the present invention may be for use in a supermarket, department store, or wholesaler using wireless (802.11) IP phones or customer service. When a store clerk walks around using a wireless (802.11) IP phone, the clerk may encounter loss of the radio signal. In accordance with certain embodiments of the invention, the call is put on hold when the signal loss is encountered, and automatically restored when the clerk moves to a place in which the radio signal is recovered. The call relay station can be located at the store close to all of the wireless (802.11) IP phone used in the store.
[0037] Although the present invention has been described with several embodiments, a myriad of changes, variations, alterations, transformations, and modifications may be suggested to one skilled in the art, and it is intended that the present invention encompass such changes, variations, alterations, transformations, and modifications as fall within the scope of the appended claims.
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A method for facilitating a call session includes receiving a request to establish a call session between a wireless phone and a remote phone, and establishing a call session between the wireless phone and the remote phone. The call session includes a first connection with the wireless phone and a second connection with the remote phone. The method further includes monitoring the first connection to determine if there is a connection loss of the first connection, and determining that there is a connection loss of the first connection. In response to determining that there is a connection loss of the first connection, the method further includes holding the second connection with the remote phone, attempting to reestablish the first connection with the wireless phone, and resuming the call session in response to the first connection being reestablished.
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FIELD AND BACKGROUND OF THE INVENTION
The present invention is generally related to a valve arrangement for a controllable two-tube vibration absorber, and more particularly, to a valve arrangement for a controllable two-tube vibration absorber with a power cylinder whose interior space is subdivided into a first and a second power chambers by means of a slidable piston, and with a balancing chamber partly filled with oil. The inventive valve arrangement includes a valve body which is actuatable by an electromechanical transducer and prestressed by means of a spring. The aforementioned valve body influences a hydraulic connection through which a unidirectional flow is passed. In the traction stage, the unidirectional flow exists between said first power chamber, on one hand, and said second power chamber jointly with said balancing chamber, on the other hand. In the thrust stage the unidirectional flow exists between said first power chamber jointly with said second power chamber, on one hand, and said balancing chamber, on the other hand.
A valve arrangement generally related to the present invention is known from the older, not anticipated patent application of this applicant, No. P 41 08 026.2. The valve arrangement of the vibration absorber shown there is configured as a single-stage slide valve. The position of the valve slide depends on the hydraulic pressure differential coming about across the slide valve, the volumetric flow rate passing through the valve, and the actuating current of the electromechanical transducer.
The prior-art valve arrangement has the disadvantage that the valve body is furnished with a ring-shaped surface which is subjectable to the hydraulic pressure existing in the first power chamber and is, therefore, not pressure-balanced. Therefore, that valve can only perform a pressure-limiting function that has a negative bearing on the functioning of the vibration absorber. The drawback is particularly acute in the range of low volumetric flow rates in which a strong transmission of vibrations takes place from the wheels to the body of an automotive vehicle which is equipped with such state-of-the-art vibration absorbers.
Therefore, one object of the present invention is to provide a valve arrangement including a valve body that is actuatable by an electromechanical transducer that improves the functioning of the vibration absorber. The present invention improves the behavior of the vibration absorber and the related desired cushioning comfort, especially in the range of low volumetric flow rates.
SUMMARY OF THE INVENTION
According to the present invention the object of improving vibration absorber performance is attained in part because the valve body is designed to be pressure-balanced. Also, in a first range of volumetric flow rate the valve body performs a restricting function that depends on the actuation of the electromechanical transducer. The valve body simultaneously interacts with a second, pressure-unbalanced valve body which in a second range of volumetric flow rate influences a second hydraulic connection through which a unidirectional flow is passed. In the traction stage, this second hydraulic connection exists between said first power chamber, on one hand, and said second power chamber jointly with said balancing chamber, on the other hand. In the thrust stage, this second hydraulic connection exists between said second power chamber jointly with said first power chamber, on one hand, and said balancing chamber, on the other hand. The second valve body performs a pressure-limiting function which also depends on the actuation of the electromechanical transducer during the thrust stage.
The present invention provides the following advantages.
In the range of low vibration absorber speeds and low vibration absorbing forces, which are decisive for desirable cushioning comfort, a vibration absorber equipped with the inventive valve arrangement is more finely dosable.
If the electromechanical transducer actuation fails, the vibration absorber will remain operative as a passive absorber. By appropriate design measures a valve arrangement in accordance with the present invention can have one of the potential characteristic curves preadjusted as the passive characteristic curve of the absorber in the event of the electromechanical actuation missing or failing.
In contrast with a force-controlled arrangement, the inventive valve arrangement, controlled on the basis of characteristic curves, can tolerate a malfunctioning the electromechanical actuation. For example, signalling times or digitalization errors do not hinder the effectiveness of the inventive arrangement.
By an expedient shaping of the individual characteristic curves a change of the position of the vibration absorber valve will be necessary exclusively in case of a variation of the initiating condition, undulation of the driveway or driving situation. Contrary to this, a force-depending actuation of the vibration absorber must react to any variation of the absorber speed.
A further advantage of the present invention is that the second valve body is actuatable by a second electromechanical transducer. In this conjunction it will be particularly expedient if and when said second valve body is configured as a part of the second electromechanical transducer, for example as the armature of an electromagnet or as a coil support of a plunger coil which interacts with a permanent magnet. Optional characteristic curves can be realized with an arrangement of this kind, since the restricting and the pressure-limiting functions will allow to be adjusted independently of each other. For this reason, the inventive valve arrangement is extremely well suited for test purposes.
In another embodiment according to the present invention, an advantageous linkage of the restricting function and the pressure-limiting function only is attained when making use of only one electromechanical transducer because the second valve body is influenced indirectly through the excursion of the first valve body by the actuation of the electromechanical transducer.
A compact-type design according to one embodiment of the inventive valve arrangement includes the first valve body configured in the shape of a bushing being slidingly guided on a stationary cylindrical guide element. In the latter embodiment, the bushing interacts with cross-sectional areas of flow which are configured in the guide element and are preferably designed in the shape of slots, particularly as annular grooves. In this conjunction, the second hydraulic connection is formed by a first bore which is configured in the guide element, by a cylindrical chamber which accommodates the second valve body and the spring, and by a second bore which is configured in the bushing coaxially with the first bore.
In another embodiment of the present invention, the second valve body is configured in the shape of a ball. The second valve body is prostressed by a spring and interacts with a sealing seat being at one end of the first bore. An inventive valve arrangement featuring such a configuration is distinguished by a simple design that provides a simply dimensioned "sensing area" at the second valve body.
In accordance with a preferred embodiment of the present invention, the second hydraulic connection is formed by cross-sectional areas of flow, for example by slots, bores or annular grooves in the guide element, the second valve body designed as a second bushing slidingly guided on the guide element interacting with a sealing seat configured on the guide element. The sealing seat is preferably a step which has a smaller or larger diameter. A better splitting-up of the volumetric flow rates will be rendered possible by this provision. In addition, manufacture of the arrangement is simplified and favorable prerequisites are created for a compensation of the force of flow.
In this context, it will be particularly advantageous for the smooth functioning of the inventive valve arrangement of a corresponding vibration absorber if, during the interaction of the first valve body with the cross-sectional areas of flow, a compensation of the hydraulic forces turning up in the effective range takes place. This measure affords the additional advantage of reducing the energy requirements of the electromechanical transducer.
The compensation of the forces of flow mentioned before is, for example, attained in that the bushing and/or the chamber which is disposed behind the cross-sectional areas of flow as seen in the flow direction are configured to safeguard a deviation of the volumetric flow. In this context, the front surface of the valve body, designed in the shape of a bushing, which interacts with the cross-sectional areas of flow preferably has a truncated cone-shape.
According to another embodiment of the present invention, the forces of flow are counteracted because the cross-sectional areas of flow end up in an annular hydraulic chamber which is connected to the outlet of the valve arrangement. In this embodiment, the resulting static pressure within the annular chamber effectively induces a hydraulic force component which counteracts the Bernoulli's forces acting on the bushing.
An inexpensive, space-saving embodiment of the inventive valve arrangement is achieved wherein the first valve body is conceived as being a part of the electromechanical transducer. In this embodiment, the electromechanical transducer may either be configured as a plunger coil interacting with a permanent magnet whose coil support is formed by the first valve body or as an electromagnet whose armature is formed by the first valve body. The former construction features a more favorable dynamic behavior, whereas the electromagnet used in the latter provides a sturdy assembly which is not susceptible to trouble.
Further embodiments of the present invention include means to guarantee the functioning of the vibration absorber, equipped with the inventive valve arrangement, even in case of a failure of the electromechanical transducer; means for performing a so-called fail-safe function. The fail-safe means safeguard a predeterminable mean restricting function and a predeterminable mean pressure-limiting function in the event of a failure of the electromechanical transducer. In one embodiment, the first valve body is, for example, prestressed by a second spring which counteracts the spring prestressing the second valve body. In this context, it must be safeguarded that the second hydraulic connection remains closed in the event of a current failure. Another embodiment includes means to perform the former function mentioned above which includes a third hydraulic connection provided between the inlet and the outlet of the valve arrangement which is simultaneously released by the first valve body when the hydraulic connection is closed by the force of the second spring. The use of a simple unidirectionally acting transducer is rendered possible by this provision.
If, however, the latter-mentioned function is performed, then the functioning reliability of the inventive valve arrangement will be increased since mean forces will occur even at elevated vibration absorber speeds. To realize this effect, the hydraulic connection is partly closed by a third spring which counteracts said spring which acts on the first valve body, in which case the electromechanical transducer will be effective bidirectionally.
In a further advantageous embodiment another possible means to perform a fail-safe function of the kind mentioned above consists in that a fourth spring is supported at a force-transmitting element which is actuatable by a third electromechanical transducer. The force-transmitting element affords a transmission of the force of the fourth spring to the first valve body in the event of a switch-off or a failure of the third electromechanical transducer. This measure constitutes a fail-safe process for unidirectionally acting transducers.
In order to achieve a sufficient, more uniform spreading of the characteristic curves for small volumetric flow rates, means are provided in further embodiments that ensure a nonlinear dependence of the cross-sectional area of opening of the cross-sectional areas of flow on the excursion of the first valve body. In this instance, the first valve body may, for example, be furnished with notches on its front surface or with bores in its range interacting with the cross-sectional areas of flow. As an alternative, the cross-sectional areas of flow which are provided in the guide element may also be configured in the shape of bores.
In order to avoid soiling or impurities causing clamping of the valve bodies, one advantageous further development of the subject matter of the present invention is that the hydraulic connections are preceded by filter elements. For example, one filter element is positioned in the guide element before the cross-sectional areas of flow.
Within another advantageous embodiment of the present invention, the first valve body is a part of a travel sensor device interacting with a controller or is coupled to such a device. The controller will generate a correcting variable by comparing the actual position of the first valve body to a preselected set position. The corresponding variable brings about a force of the electromechanical transducer that may exceed the stationary force required for maintaining the first valve body in the set position. The dynamics of the inventive valve arrangement will, therefore, be greatly increased.
In order to further reduce the power requirements of the electromechanical transducer, the first valve body can be pilot-controlled. This provision simultaneously reduces the susceptibility of the valve arrangement to soiling.
Further details, features and advantages of the present invention will be revealed by the following description of a total of seven embodiments, making reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a controllable two-tube vibration absorber equipped with the inventive valve arrangement in a diagrammatic sectional representation;
FIG. 2 shows characteristic curves that can be realized with the inventive valve arrangement; and
FIGS. 3, 4A, 4B, 5A, 5B, 6 and 7 respectively show a first to seventh design version of the inventive valve arrangement in the sectional representation corresponding to that in FIG. 1, in an upscaled illustration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The two-tube vibration absorber 1 which is represented diagrammatically in FIG. 1 is comprised of a power cylinder 2 and an external tube 3 positioned coaxially with power cylinder 2, so that a storage tank or balancing chamber 4 which has a circular ring-shaped cross section, partly filled with oil, is formed between them. The interior space of power cylinder 2 is subdivided by a piston 6 being slidable by a piston rod 5 into a first power chamber 7 being configured above the piston 6 and a second power chamber 8 being configured beneath the piston.
First power chamber 7 is connected to an inlet 41 of a valve arrangement 11 whose outlet 42 is in connection, on one side, with the balancing chamber 4 and, on the other side, through a first non-return valve 9 with the second power chamber 8. Furthermore, a hydraulic connection 78 is provided which connects the second power chamber 8 through a second non-return valve 10 to the first power chamber 7. In the event of movement of the piston 6, a flow will occur in one direction only through the valve arrangement 11 which serves for the variation of the cross-sectional area of passage between the first power chamber 7, the second power chamber 8, and the balancing chamber 4, respectively, during the traction stage. Similarly a unidirectional flow will occur to effectively vary the cross-sectional area of flow between the second power chamber 8 and the balancing chamber 4 during the thrust stage.
FIG. 2 shows a diagrammatic representation of the characteristic curves of the vibration absorber shown in FIG. 1; the dependence of the hydraulic pressure existing within the vibration absorber on the volumetric flow passing through the valve arrangement 11 in the presence of different ratings of the energizing current which actuates an electromechanical transducer 14 of the controllable valve arrangement 11.
A first embodiment of the inventive valve arrangement 11 which is shown in FIG. 3 comprises a valve housing 39 which accommodates a cylindrical guide element 13 presenting cross-sectional areas of flow 24. Within guide element 13 a first valve body 12 is slidingly guided and is positioned to be adjustable by means of electromechanical transducer 14. First valve body 12 is configured in the shape of a tubular bushing which interacts with the cross-sectional areas of flow 24. First valve body 12 defines, within the interior space of guide element 13, a cylindrical chamber 19 into which a bore 17, in guide element 13 beneath the cross-sectional areas of flow 24, and a bore 18, in valve body 12, end up. Sealing seat 20 is at the rear end of the bore 17. A second valve body 15 interacts with sealing seat 20. Second valve body 15 is prestressed by a spring 16 taking support at the first valve body 12. Second valve body 15 is a ball in the illustrated example. In this instance, the electromechanical transducer 14, for adjusting the position of first valve body 12, is an electromagnet whose armature straddles the first valve body 12. Beyond this, a compression spring 33 counteracting the spring 18 is clamped in between the first valve body 12 and the bottom of the valve house 39 whose function will be explained in more detail below.
For the following description of the functioning of the inventive valve arrangement 11 it is initially assumed that the windings of the electromagnetic transducer 14 are not energized (middle characteristic curve in FIG. 2) and that the cross-sectional areas of flow 24 which are formed by slots or annular grooves are not covered by the first valve body 12, thereby providing a hydraulic connection between the inlet 41 and the outlet 42 of the valve arrangement. The small volumetric flow (volumetric flow range A in FIG. 2) which is initiated by a slight uniform movement of the piston 6 leads to an increase of the pressure which is determined by the opening of the cross-sectional area of flow 24 and which acts on the part-surface of second valve body 15 that faces inlet 41. Sealing seat 20, in the guide element 13, will be maintained closed by the force of the spring 16 and, when the windings of the electromagnetic transducer 14 are energized, by the actuating force exerted by the transducer 14. Sealing seat 20, therefore, remains closed until, for example, the resulting pressure from an increase in the volumetric flow (volumetric flow range B in FIG. 2) overcomes the closing force which acts on the second valve body 15. The opening of the sealing seat 20 brings about a movement of the bushing-shaped first valve body 12 and, consequently, a wider opening of the slots 24. Therefore, the volumetric flow passing through the slots 24 increases and the pressure ruling at the inlet 41 of the valve arrangement 11 subsequently decreases. The described procedure will continue until a condition of equilibrium of forces will exist again at the valve bodies 12, 15.
It will be advantageous when the portion of first valve body 12 that interacts with the cross-sectional areas of flow (slots) 24 has the shape of a truncated cone. The portion of first valve body 12 having a truncated cone shape is referred to as front surface 26. In this way the volumetric flow will be deviated during its passage through the slots 24 which results in an impulse effect being suited to compensate for the Bernoulli's forces that are caused by the flow and which act in the closing direction of the cross-sectional areas of flow. When the force generated by the electromechanical transducer 14, which preferably acts bidirectionally, changes, the position of the pressure-balanced first valve body 12 changes. Simultaneously, the closing force of the second valve body 15 which is exerted by the spring 16 varies.
In the de-energized condition of the transducer 14, the cross-sectional areas of flow 24 are kept partly closed by the action of the compression spring 33 taking support at the first valve body 12, so that in the event of a failure of the electromechanical transducer a predeterminable mean restricting function as well as predetermtnable mean pressure-limiting function are maintained.
Another embodiment of the inventive valve arrangement 11 is shown in FIG. 4A. Electromechanical transducer 14 is configured in the shape of a plunger coil 29 interacting with a permanent magnet 28 with the first valve body 12 serving simultaneously as a coil support of the prementioned plunger coil 29. The second valve body 15 is formed by a tubular bushing 21 which is slidingly guided on the guide element 13. Second valve body 15 interacts with the cross-sectional areas of flow, slots 43, being provided in said guide element 13, and with a sealing seat 22 defined by guide element 13. For flow technique reasons it will be advantageous in this context when the front surface 44 of the bushing 21 has a truncated cone shape. Filter elements 38 are provided in order to protect the functionally important ranges of the cross-sectional areas of flow 24, 43 from soiling. FIG. 4A shows one filter element 38 arranged upstream of the cross-sectional areas of flow 24.
The chamber 25 which is configurated downstream of the cross-sectional areas of flow 24 as seen in the direction of flow is preferably shaped to guarantee a deviation of the volumetric flow in order to compensate the hydraulic forces coming about during the interaction of the first valve body 12 with the cross-sectional areas of flow 24. A solution of this kind is illustrated in FIG. 4B. In the design version which is shown in FIG. 4B the cross-sectional areas of flow 24 end up in an annular chamber 27. Annual chamber 27 is connected to the outlet 42 of the valve arrangement 11 such that the static pressure coming about within annular chamber 27 will cause a hydraulic force component which counteracts the Bernoulli's forces acting on the first valve body 12.
In the embodiment shown in FIG. 5A the electromechanical transducer 14 is configured as an electromagnet 30 whose armature 31 forms the first valve body 12. The second valve body 15, or bushing 21, is guided on the guide element 13 such that bushing 21 interacts with a radial step 23. Radial step 23 has a larger diameter relative to the outer radius of guide element 13 and the inner radius of bushing 21. Radial step 23 is positioned in the range of the cross-sectional areas of flow 43 and forms the sealing seat 22, as illustrated in the lefthand half of FIG. 5. As an alternative, an arrangement shown in FIG. 5B will be feasible. In the embodiment illustrated FIG. 5B, the second valve body 15 is configured as an armature 47 of a second electromechanical transducer 35 which preferably is an electromagnet 45. In this embodiment the spring 16 prestressing the first valve body 12, or armature 31, takes support at a support not identified more closely of the second electromechanical transducer 35. The first valve body 12 may be part of a travel sensor device 40 interacting with a controller (not shown) or may be coupled to such a device.
In still another embodiment of the inventive valve arrangement 11 shown in FIG. 6, a second spring 32 is provided between the first valve body 12 and the bottom of the valve house 39. Second spring 32 counteracts spring 16 which is positioned between the two valve bodies 12 and 15 and whose force and spring constant is preselected such that the cross-sectional areas of flow 24 are covered by the first valve body 12. In its lower range,guide element 13 is simultaneously furnished with further cross-sectional areas of flow 46 which interact with a control edge 48 defined on first valve body 12. Cross-sectional areas of flow 46 afford a third connection between the inlet 41 and the outlet 42. The third connection is opened in the event of a failure of the electromechanical transducer 14 to safeguard a predeterminable mean restricting function.
FIG. 7 shows another embodiment for safeguarding a predeterminable mean restricting function and a predeterminable mean pressure-limiting function in the event of a failure of the electromechanical transducer 14. This embodiment includes a fourth spring 34 which takes support at the bottom of the valve housing 39. Fourth spring 34 prestresses a force-transmitting element 37. Element 37 is actuatable, for example, by a third electromechanical or electromagnetic transducer 36. When the third transducer 36, which is preferably electrically coupled to the first transducer 14, is actuated force-transmitting element 37 will be kept at a distance from the first valve body 12. Force-transmitting element 37 is released in the event of a current failure so the force exerted by the spring 34 is transmitted to the first valve body 12. The interaction of the two springs 16 and 34 maintain valve body 12 in a defined middle position which results in the aforementioned desired effect.
Within the framework of the inventive thought it would, moreover, appear reasonable to envisage means ensuring a nonlinear dependence of the cross-sectional area of opening defined by the cross-sectional areas of flow 24 on the excursion of the first valve body 12. For example, valve body 12 may include notches on its front surface or be furnished with bores in the longitudinal range along valve body 12 interacting with the cross-sectional areas of flow 24. Another possibility consists in configuring the cross-sectional areas of flow 24 in the guide element 13 in the shape of bores. Further embodiments can, of course, be imagined in which the first valve body 12 is actuatable by a pilot stage.
It will be apparent to one skilled in the art that the preceding description is exemplary rather than limiting in nature. Modifications are possible without departing from the purview and spirit of the present invention, the scope of which is limited only by the appended claims.
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A controllable valve arrangement for controlling two-tube vibration absorbers comprises a power cylinder with an interior space subdivided into a first and a second power chambers by virtue of a slidable piston, and with a balancing chamber partly filled with oil. A valve body is actuated by an electromagnetical transducer and prestressed by a spring. The valve body influences a hydraulic connection through which a unidirectional flow is passed. In a traction stage, a unidirectional flow exists between the first power chamber, on one hand, and the second power chamber jointly with the balancing chamber, on the other hand. In a thrust stage, a unidirectional flow exists between the first power chamber jointly with the second power chamber, on one hand, and the balancing chamber, on the other hand.
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FIELD OF THE INVENTION
[0001] This invention relates in general to processing fruit, and in particular, to a method of processing avocados.
BACKGROUND OF THE INVENTION
[0002] An avocado is an organic green colored tropical fruit that is roughly spherical or ellipsoid in shape. Avocados generally have a major axis length ranging from 2 to 4 inches long, contain a single hard seed in the center of the fruit, and have a wrinkled leathery outer skin or rind. When harvested ripe and processed within a few hours, the edible pulp of this fruit is firm and easy to remove. However, if the fruit is not ripe, the pulp is too hard to effectively remove from the fruit. If the fruit is over ripe, the pulp is too soft and mushy to effectively remove from the fruit. A variety of methods are employed to extract the pulp from the avocado, however many of these methods require extensive manual labor.
[0003] For example, a laborer might hand wash, slice, and depit the avocados in a processing system. With this system, a great deal of manual labor and time is involved in processing the avocados. Furthermore, once the avocado has been sliced and depitted, more manual labor is required in removing the pulp from the avocado. While manual processing may be a successful method, this system of processing requires a large amount of physical labor and also involves a large amount of time associated with this labor
SUMMARY OF THE INVENTION
[0004] In this invention, an automated system processes the avocados as they work their way along a continuous path. The avocados are preferably heated and cooled prior to squeezing in order to increase the ease with which the pulp is removed from the rind. Following the heating and cooling process, the avocados are conveyed along a path where they are sliced in half with a rotating blade. The avocado halves are then conveyed to a squeeze cell where they are depitted and squeezed as they continue along a desired path. As the avocado halves continue through the squeeze cell, a squeezing force is applied to the halves, causing the pulp to be removed from the rind. The pulp is collected and conveyed for further processing, as the rind is then disposed of.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a flow chart of the method for processing avocados as comprised by the invention.
[0006] FIG. 2 is a schematic of the heating and cooling tanks with conveyor belts.
[0007] FIG. 3 is an isometric view of the mesh conveyor belts employed in the heating and cooling tanks.
[0008] FIG. 4A is an end view of the feed conveyors leading to the slicer.
[0009] FIG. 4B is an isometric view of the feed conveyors leading to the slicer.
[0010] FIG. 5 is a schematic side view of the feed conveyor as it passes through the slicing mechanism.
[0011] FIG. 6 is a top view of the transition from the feed conveyor to a transfer conveyor leading to a squeeze cell.
[0012] FIG. 7 is a side view of the squeeze cell with depitting stations.
[0013] FIG. 8A is a sectional view of a V-shaped clamp with guide tracks, with fingers in an open position, and taken along the line 8 A- 8 A of FIG. 7 .
[0014] FIG. 8B is a sectional view of the V-shaped clamp with guide tracks, with fingers in a gripping position, and taken along the line 8 B- 8 B of FIG. 7 .
[0015] FIG. 8C is a sectional view of the V-shaped clamp with guide tracks, with fingers in a near closed position, and taken along the line 8 C- 8 C of FIG. 7 .
[0016] FIG. 9A is a sectional view of alternate embodiment of a clamp with guide tracks, with dual hinged fingers in an open position.
[0017] FIG. 9B is a sectional view of the clamp and guide tracks of FIG. 9A , with the dual hinged fingers in a gripping position.
[0018] FIG. 9C is a sectional view of the clamp and guide tracks of FIG. 9A , with the dual hinged fingers in a near closed position.
[0019] FIG. 10A is a sectional view of alternate embodiment of a clamp with guide tracks, with concave fingers in an open position.
[0020] FIG. 10B is a sectional view of the clamp and guide tracks of FIG. 10A , with the concave fingers in a gripping position.
[0021] FIG. 10C is a sectional view of the clamp and guide tracks of FIG. 10A , with the concave fingers in a near closed position.
[0022] FIG. 11 is a schematic top view of the idle roller squeezing device.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Since avocados are an organic product, the size and shape are not within human control; therefore, it is the responsibility of other sorting systems to group like size fruit together and to reject damaged fruit prior to delivery to this process.
[0024] Referring to FIG. 1 , the method for processing avocados as comprised by this invention involves passing the avocados through the following: a heating and cooling station 21 , then a slicing station 23 , and finally, a depitting and squeezing station 25 .
[0025] Referring to FIG. 2 , the avocados are conveyed through a brusher 31 , which cleans the outer skin of the avocados using a combination of liquid spray and brushing. After the avocados leave brusher 31 , they are immersed and conveyed through a heated liquid tank 34 by means of mesh conveyor belts 33 . Preferably, the avocados are immersed in the heated liquid for thirty seconds. The avocados are then exposed to room temperature air 35 as they are transferred from the heated liquid tank 34 to the chilled liquid tank 36 . Preferably, the avocados are exposed to room temperature air for eight seconds. The avocados are then immersed, and conveyed through a chilled liquid tank 36 by means of mesh conveyor belts 33 . Preferably, the avocados are immersed in the chilled liquid for thirty seconds. The avocados are then exposed to room temperature air 37 as they are transferred from the chilled tank 36 to the chilled sanitizing liquid tank 38 . Preferably, the avocados are exposed to room temperature air for eight seconds. The avocados are then immersed, and conveyed through a chilled sanitizing liquid tank 38 by means of mesh conveyor belts 33 . Preferably, the avocados are immersed in the chilled sanitizing liquid for thirty seconds. Referring to FIG. 3 , mesh conveyor belts 33 travel in the same direction, above and below the avocados.
[0026] Referring to FIGS. 4A and 4B , the avocados travel from the heating and cooling station to the slicing station on feeder conveyors 41 . The feeder conveyor is constructed of two independent parallel flat belt conveyors 41 that are opposing yet inclined to each other along their short axis, thereby forming a V-trough. The conveyors 41 are essentially mirror image in design and the two belts 41 run in the same direction. The angle of inclination between the flat belt conveyors 41 is adjustable. The avocados are loaded into the open space between the two conveyors 41 and rest on the bottom tangential surfaces. A small gap is maintained at the bottom of the conveyors 41 and is adjustable. The avocados continue along feeder conveyors 41 and through the slicing station.
[0027] Referring to FIGS. 4A and 5 , towards the end of feeder conveyors 41 , a rotating saw blade 51 is mounted to allow for vertical adjustment. The blade 51 passes through the gap at the bottom of conveyors 41 . Guided rollers 42 engage each side of the blade 51 in the gap to minimize deflection, and to ensure precision. Blade 51 is used to automatically cut through the avocado and its seed in order to produce two halves of roughly equal dimension. Ideally, the cut surface is vertical and along the long axis at the centerline of the avocados. As the avocados continue down the conveyors 41 , the saw blade 51 rotates in the same direction as the conveyors 41 in order to push the fruit further into the trough of conveyors 41 as the fruit passes through the blade 51 , thereby increasing the grip and improving the cut quality of each half. At the bottom of rotation, the blade 51 also promotes transport of the avocado halves once separated since the blade 51 spins in the same direction as avocados travel. This is advantageous since avocados are fairly lightweight and are only supported on the bottom tangents.
[0028] To prevent fruit from moving during the cut, multiple powered O-ring belts 53 are provided above the fruit. Belts 53 extend from blade axles to a fixed axle on a wedge 55 , forward of the end of conveyors 41 . Belts 53 extend from the blade axles to a fixed axle ablve conveyors 41 . Wedge 55 is a stationary, generally V-shaped member for directing one avocado half left and the other right as illustrated in FIG. 4A . Belts 53 are powered by pulleys 54 located on either side of blade 51 and contact the fruit on tangential surfaces. Pulleys 54 are slaved off the saw blade shaft, and as such, the contacting surfaces of belts 53 run in the same direction as the avocados. Upstream of saw 51 , belts 53 are horizontal and spaced along conveyor 41 to prevent stacked or under-ripe avocados from moving away from blade 51 ; downstream of saw 51 , belts 53 incline downward promote transfer of avocado halves through wedge 55 and down the chute in a controlled manner. Downstream belts 53 are generally parallel with the upper edge of wedge 55 .
[0029] Referring to FIG. 6 , transfer conveyor 61 is used to separate fruit halves and to transfer halves between the slicing station and squeezing station. Just after the avocados begin passing through saw 51 or afterwards, the bottom of the fruit is wedged apart laterally by wedge 55 . The flat bottom of the fruit half falls onto transfer conveyor belt 61 . Avocado halves must then be separated from a common drop point at the centerline of the transfer conveyor 61 to the outside edges of conveyor 61 . The transfer is accomplished by side guides 63 that direct the fruit from a common input to two parallel outputs. It is necessary in the squeezer section to have the fruit facing with the cut face down prior to entering the squeezer. In one embodiment, an optical sensor can be used to detect if an avocado is facing correctly by looking at the color. The outside skin is significantly darker that the color of the pulp, which is light green. In the event that the fruit is disoriented, then an escapement can automatically push the fruit toward the center of the conveyor 61 . The fruit will fall off the end of the conveyor 61 into a holding bin, where an operator can manually load it later.
[0030] Referring to FIG. 7 , which is a side view of the squeezing cell, avocados continue along the transfer conveyor 61 until they reach the depitting and squeezing station where: 1) the seed is removed; 2) the fruit pulp is separated from the skin; and 3) the remaining materials are taken away from the machine. The squeezing station has two parallel lanes that process each respective half of the avocado. Each lane is independently powered and controlled and utilizes a corrosion-resistant attachment chain 72 as the transport devices. The chain 72 is located above the transfer conveyor and is driven such that the bottom of the chain 72 travels in the same direction & speed as the transfer conveyor 61 .
[0031] Referring to FIGS. 8A , 8 B and 8 C, each chain attachment link contains a finger assembly, consisting of a hinged joint 81 and two flat fingers 83 attached to the pivot axis that act together to form a V-shape. Each finger assembly contains a center hinge pin 81 , two flat fingers 83 , each with a small slot (not visible) to improve friction, one or more torsion springs (not visible) to urge the fingers closed, a pin 85 welded perpendicular toward the outside of each finger 83 , and idler rollers (not visible) which ride on the pin 85 . These finger assemblies are attached to the chain 72 permanently or with removable fasteners for service and cleaning.
[0032] FIGS. 9A , 9 B, and 9 C illustrate an alternate embodiment of the finger assembly of FIGS. 8A , 8 B, and 8 C, consisting of common member 91 , two hinged joints 93 , and two flat fingers 95 attached to the pivot axes that act together to form a V-shape. Each finger assembly contains hinge pins 93 , two flat fingers 95 , each with a small slot (not visible) to improve friction, one or more torsion springs (not visible) to urge the fingers closed, a pin 97 welded perpendicular toward the outside of each finger 95 , and idler rollers (not visible) which ride on the pin 97 .
[0033] FIGS. 10A , 10 B, and 10 C illustrate an alternate embodiment of the finger assembly of FIGS. 8A , 8 B, and 8 C, consisting of slot joints 100 , and two concave fingers 105 attached to the pivot axis that act together to form a V-shape. Each finger assembly contains two pins 101 , a slot 103 , two concave fingers 105 , each with a small slot (not visible) to improve friction, one or more torsion springs (not visible) to urge the fingers closed, a pin 107 welded perpendicular toward the outside of each finger 105 , and idler rollers (not visible) which ride on the pin 107 .
[0034] Referring back to FIGS. 7 , 8 A, 8 B, and 8 C, each pin 85 is captured above by an upper guide track 77 , and below by a lower guide track 78 . The gap distance between guides 77 , 78 is used to limit the pivot angle from open to close between fingers 83 or the relative motion of just one finger. Initially, guide tracks 77 , 78 ensure that the fingers are fully open by restricting the movement of pins 85 ( FIG. 8A ). Once the chain reaches a parallel attitude to the transfer conveyor 61 , guide tracks 78 are lowered, and pins 85 are no longer restricted. As a result, the torsion spring in the fingers causes the fingers to close and grip the avocado halves. The spring constant must be selected to provide sufficient torque to grip the avocado halves between the fingers, but must not be too great to cause premature extraction of the fruit. If there is an avocado half available, fingers 83 will close until they grip the fruit. ( FIG. 8B ). If a fruit is not available, lower guides 78 prevent the finger assembly from closing fully to avoid damage.
[0035] As the avocados are gripped and conveyed along the chain path, the fruit passes over a slotted plate 74 so that the bottom surface of the avocado half is once again supported. The entry of the plate begins before de-seeder 73 and ends past de-seeder 75 . Each avocado half passes through two in-line de-seeders 73 , 75 per lane. A de-seeder assembly 73 , 75 consists of a powered blade with four points and this blade is attached to a drive shaft axis horizontal and perpendicular to the direction of travel. As the blade 73 , 35 passes through the fruit, one or more points of the blade 73 , 75 engage the seed and extract it from the fruit.
[0036] After the seed has been removed and the avocado half leaves the skid plate 74 , the guides 77 , 78 are configured to gradually force closure of the spring fingers 83 . The upper guides tracks 77 bend downward towards the lower guide tracks 78 . As the distance between the chain 72 and upper guides 77 is increased, a downward force is exerted on pins 85 . The downward force on pins 85 forces fingers 83 closer together ( FIG. 8C ). The lower guides 78 ensure that fingers 83 do not close more than a desired amount. The wedge action of the fingers 83 forces the avocado pulp to separate from the skin, where it falls down into a container, transport conveyor, or other similar transport method (not visible). Since the force on pins 85 can be significant, the pins 85 have roller bushings (not visible) intended to reduce slide friction. To improve the yield of extracted avocado fruit from skin, the finger assembly then passes through a secondary squeeze section 79 that applies significantly higher force to the fruit.
[0037] Referring to FIG. 10 , an optional second squeezer consists of idler rollers 113 on either side of the finger assembly path 112 that are mounted on a base 115 which pivots on the frame 117 . The other end of the base 115 is attached to a pneumatic cylinder 119 or similar device that can provide force. The pneumatic cylinder 119 force can be adjusted via regulator regardless of stroke and it can be attached to a valve actuator in order to retract the wheels for cleaning. Each roller 113 rolls on the outer sides of fingers 83 ( FIG. 8A ), pushing them tightly together.
[0038] Referring back to FIG. 7 , after the pulp has been extracted and the fruit is in a safe location, the guide tracks 77 , 78 are arranged to force open the finger assemblies. The remaining products fall from the fingers 83 , into a waste container, transport conveyor, or other similar disposal method (not visible). While the fingers 83 are held in an open position, one or more nozzles 81 spray pressurized fluid toward the fingers in order to remove debris. The cleaning fluid usually contains water and sanitizer chemicals. The fingers 83 then travel in an open position on chain 72 to the initial starting point, and the process is repeated.
[0039] The invention has significant advantages. By processing the avocados while they continuously travel on a conveyor belt, the manual labor associated with such a process is eliminated. Furthermore, the automated system allows the avocados to be processed at a high rate of speed, ensuring that pulp is removed from the avocados in a quick and efficient manner.
[0040] While the invention has been described in only one of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.
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An avocado processor extracts the pulp from the fruit. The avocados are heated, cooled, sliced in half, depitted, and squeezed all while continuously traveling along a conveyor path. The squeezing is handled by V-shaped finger assembly. Guides force the fingers to close as they move along the path.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/784,108, entitled “FPGA Based ATCA (Advanced Telecommunications Computing Architecture) Platform,” filed on Mar. 14, 2013, the disclosure of which is hereby incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
This invention, in various embodiments, generally relates to computing systems and, more particularly, to field programmable gate array (FPGA)-based systems for communications.
BACKGROUND
Hardware designers, particularly those working on blades or chassis, are currently faced with huge challenges. The needs of the communications network infrastructure, and next generation communications applications, are rapidly changing and cannot be served by existing solutions.
Field Programmable Gate Arrays (FPGAs): Hardware system designers are facing major challenges meeting the needs of evolving markets such as telecommunications and high-performance computing. Application performance and energy efficiency requirements are escalating, as is the need for flexible solutions that can adapt to evolving standards and market needs. Design complexity has soared, creating severe challenges in managing design and verification costs, time-to-market, and overall system performance and power consumption. Increasingly, hardware designers have turned to FPGAs instead of microprocessors or Application Specific Integrated Circuits (ASICs) to meet their design needs. Microprocessors, while fully programmable, can provide the required flexibility, and because a given product is customized through software, they address the time-to-market constraints. However, microprocessor solutions often fail to provide sufficient performance and energy efficiency to meet product requirements. ASICs, on the other hand, while capable of providing high performance and energy efficiency, are expensive to design (requiring many months or years) and therefore often fall short of time-to-market requirements and may be too expensive to develop.
FPGAs have evolved from simple logic fabrics used as glue logic concentrators to multi-million-gate programmable systems-on-a-chip used as ASIC and micro-processor replacements. They have been used in a wide variety of applications, from flexible network routing components, to high-performance general purpose computing devices, to special purpose signal processors. Driven by Moore's Law, ever-larger FPGAs are being used in a widening range of applications with ever-increasing functional requirements, and with the need for additional system-level resources (such as memory and input/output devices) and support for operating systems and integrated development environments. Meeting these requirements requires innovative ways to architect and package FPGA systems.
A common approach to addressing the engineering of FPGA-based platforms to meet the application functional requirements is to start with a conventional computer chassis and motherboard with expansion slots, and to add in a FPGA-equipped board and the appropriate set of boards for input/output. If additional resources are needed, multiple boxes can be connected together using any of the common networking methods, such as Ethernet or Infiniband. There are many deficiencies to this approach:
1. Because of internal bus limitations and limits on the number of expansion slots, in-box communication bandwidth is limited, creating bottlenecks between the FPGA(s), I/O, memory, and CPU(s).
2. Excessive delays between boxes (through switches and routers) limits performance scalability for larger systems.
3. As a result of re-purposing an existing system architecture instead of starting with a custom design tailored to application requirements, the system power efficiency and size are far from optimal.
4. There are no built-in provisions for efficient system management or high availability operation.
Advanced Telecommunications Computing Architecture (ATCA): ATCA specifications are a series of PCI Industrial Computer Manufacturers Group (PICMG) specifications which target the requirements for carrier grade communications equipment. The series of specifications incorporates high speed interconnect technologies, processors, and Reliability, Availability, and Serviceability (RAS). The Advanced Telecommunications Computing Architecture is the largest specification effort in the history of the PICMG, with more than 100 companies participating.
The ATCA standard ensures multi-vendor interoperability, offering flexibility in applications. With commitment from top silicon and software vendors, ATCA architectures are deployed worldwide by a wide range of industries that require a chassis-based high-performance computing platform including, for example, telecommunications, cloud services, military, and aerospace.
ATCA provides a means for the telecommunications equipment market to take advantage of standardized, off-the-shelf hardware. It was designed to enable differentiation through application-layer and system level software and offers the following advantages over traditional approaches: shorter time-to-market, increased vendor choice, increased flexibility, multiple supported switch fabrics, user defined I/O, and lower cost.
The architecture is optimized to meet the connectivity requirements of a variety of applications, and typically does so while providing a 99.9999% availability rate. ATCA offers a scalable backplane environment that supports: a variety of standard and proprietary fabric interfaces, robust system management, and superior power and cooling capabilities. Each board in ATCA (up to 16 boards per shelf and 3 shelves per rack) may support up to 200 Watts in a single slot. The power is supplied to each board via redundant −48 VDC feeds. Front and rear cabling is supported for standard 600 mm total depth cabinets, prevalent in Central Office facilities.
Examples of telecommunications and network equipment manufacturers' related ATCA applications and systems include:
1. Wireless Infrastructure Equipment: base stations and radio network controllers, serving gateway support node, gateway GPRS support node, home location register, IP multimedia subsystem servers, media and application servers, media gateways and soft switches.
2. Wireline Networking Equipment: DSLAMs, multi-service switches, media servers, blade servers, and VOIP session controllers.
3. Fiber Optic Networking Equipment.
While the ATCA specification is founded on the requirements of the communications infrastructure, it is extensible to a variety of applications and environments where highly available, highly scalable, cost effective, and open architecture modular solutions are required.
What is needed is a hardware platform that can combine the advantages of FPGAs with the ATCA form factor to address the challenges of telecommunications and network equipment hardware designers.
SUMMARY
Various embodiments of the present invention feature a computational platform whose system architecture can avoid the weaknesses of microprocessor based platforms and of ASIC solutions, while addressing the common deficiencies of FPGA-based computing platforms. Various embodiments described herein bring together Field Programmable Logic Devices (FPGAs) and the Advanced Telecommunications Computing Architecture (ATCA) standard, to address some of the challenges described above. The features of various embodiments include:
1. A main-board with multiple FPGAs in a two-dimensional array interconnected with high-bandwidth links.
2. Multiple memory chips connected to each FPGA.
3. Dedicated connectors for supporting industry-standard I/O.
4. Connectors for I/O expansion using industry-standard FMC (FPGA Mezzanine Card) boards.
5. An on-board connector for an industry-standard embedded CPU board, such as COM Express or equivalent.
6. All of the above in an industry-standard ATCA (Advanced Telecommunications Computing Architecture) form factor board (blade).
The ATCA form factor can address the system power and size issues, while providing a substrate for interconnecting boards efficiently using the mid-plane network fabric. Additional expansion using the ATCA-standard Rear Transition Module (RTM) is possible for connection between ATCA racks. Within the ATCA standard, each blade and system include controllers for system management and high availability operation.
Accordingly, in one aspect, a computing system that has a form factor of the Advanced Telecommunications Computing Architecture (ATCA) standard includes a number of FPGAs. The system also includes a first set of interconnects including at least one inter-FPGA interconnect that is electrically coupled to at least one pair of FPGAs in the several FPGAs. In addition, the system includes a second set of interconnects including at least one FPGA-fiber optic interconnect coupled to an FPGA.
In some embodiments, the first set of interconnects includes serdes interconnects. The system may also include an inter-module optical transceiver link coupled to at least one FPGA-fiber optic interconnect, e.g., for providing point-to-point communication with an FPGA that is included in a different system and is located remotely from the several FPGAs of this computing system.
In some embodiments, the several FPGAs include a first FPGA disposed on a board and a second FPGA also disposed on the same board. One inter-FPGA interconnect in the first set of interconnects is coupled to both the first and second FPGAs. The system may also include a third set of interconnects including a backplane interconnect. The backplane interconnect may be electrically coupled to the first FPGA, for providing connectivity to a backplane, which can then provide connectivity to another FPGA that is disposed on a different board.
These and other objects, along with advantages and features of the embodiments of the present invention herein disclosed, will become more apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more apparent in view of the attached drawings and accompanying detailed description. The embodiments depicted therein are provided by way of example, not by way of limitation. Moreover, the drawings are not necessarily to scale, emphasis instead being placed upon illustrating aspects of the invention. In the drawings:
FIG. 1 depicts the main components of a system according to one embodiment of the invention;
FIG. 2 is a schematic block diagram of an FPGA of a computing platform, according to one embodiment of the invention;
FIG. 3 is a schematic block diagram of the high-level architecture of the interconnections between FPGAs, according to one embodiment of the invention;
FIG. 4 depicts an example BEE7 connection via optical fibers in the front panel, according to one embodiment of the invention; and
FIG. 5 depicts an example BEE7 SerDes and clock block diagram, according to one embodiment of the invention.
DESCRIPTION
One embodiment of the present invention is the BEE7 system. Referring to FIG. 1 , BEE7 is an FPGA-based computing system in the form of a blade, including a printed circuit board that interconnects a set of integrated circuits and connectors. The BEE7 blade contains 4 Xilinx Virtex-7 FPGAs; 64 GB of DDR3-1333 ECC RDIMM DRAM arranged as two 8 GB RDIMMs per FPGA; a 10 Gbps Dual-star backplane arranged as 2 GTH serDes from each FPGA to the backplane (Sone 2 connector); 768 Gbps RTM (rear transfer module) throughput arranged as 16 GTH serDes from each FPGA to the RTM; 480 Gbps front panel optical connectors arranged as 12 GTH serDes from each FPGA to the iMOT connector; and 4 FMC front panel slots for analog interfaces arranged as 8 GTH SerDes from each FPGA to its dedicated FMC slot and 80 LVDS pairs from each FPGA to its dedicated FMC slot. The blade also contains a connector for a microprocessor based control module, labeled CRM in the figure.
The BEE7 blade is based on a symmetric FPGA array architecture. Each FPGA presents the same connectivity to each other FPGA as well as to the PCB resources and input/output. Referring to FIG. 2 , the main interfaces to the FPGA are 2 RDIMM banks, supporting DDR3 protocol with 2/4/8 GB capacity options, 1333 MHz speed, and Error Check and Correction (ECC); 400 Gbps on-board full mesh inter-FPGA connections; ATCA backplane (10GE) dual-star; 640 Gbps ATCA rear transfer module (RTM) flexible network expansion; 480 Gbps optical front panel (iMOT) inter-blade communication; FPGA Mezzanine Card (FMC) for analog interfaces; Gigabit Ethernet to the front and back panels; LVTTL GPIO to the front panel; RS232 (USB); SelectMAP (USB); EEPROM and Flash memory; and LEDs and reset.
Referring to FIG. 3 , the BEE7 blade is designed to take advantage of the 80 GTH SerDes available in each Virtex-7 VX690T FPGA to create a configuration that allows for high speed transfer of data between FPGA devices on the same board, between FPGA devices in different boards across the backplane, between FPGA devices in different boards or systems across front panel fiber optics (iMOT connectors), between FPGA devices and cards residing in FMC slots, and between FPGA devices and networking interfaces residing on the RTM.
The BEE7 blade is meant to be equipped in an ATCA chassis as needed by its application, for instance in a telecommunications service providers local exchange, in a cell tower, or in a data center. The BEE7 blade is a high performance platform that achieves a high degree of flexibility for Network I/O connectivity via Rear Transfer Module (RTM) Options. A variety of copper and fiber interfaces are supported by using different RTM cards.
The Inter-Module Optical Transceiver (iMOT) is a high-throughput link intended to connect FPGAs in different BEE7 blades in a point-to-point manner. It consists of two transceivers, one for transmission (TX) and one for reception (RX), each supporting 120 Gbps over twelve fibers. The fibers are bundled in 24-fiber cables that connect to 24-fiber parallel optical sockets (MPO in the figure). The iMOT supports up to 100 meter MMF (Multi-Mode Fiber). FIG. 4 depicts the iMOT connections inside and outside the BEE7 for a total of 480 Gbps aggregated throughput.
FIG. 5 shows in detail how the BEE7 blade and its FPGAs are clocked. The top of the block diagram shows the connection to the other FPGAs on the board as well as the Gigabit Ethernet connection. The left hand side shows the front panel (i.e. FMC and iMOT connectors). The right hand side shows the back panel (i.e. zone 2 and zone 3 connectors). A CPRI-based RTM is also shown in this side. Finally, the bottom of the block diagram shows clock inputs on SMA connectors and the PLL.
The BEE7 blade is a high performance platform that achieves a very high degree of flexibility for a wide range of applications through support for FMC cards. For example, it supports radio I/O connectivity for wireless applications through the use of ADC and DAC cards.
The BEE7 is the first off-the-shelf platform for telecommunications that allows suppliers to keep the same fully programmable hardware across the product life cycle. BEE7 can be used for early algorithm exploration, research, development, real time verification, prototyping, field trials, limited deployment, and product upgrades.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, because certain changes may be made in carrying out the above method and in the construction(s) set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
While the invention has been particularly shown and described with reference to specific embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced.
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A computing platform includes an array of interconnected field programmable gate arrays (FPGAs), memory, and external input/output interfaces. The platform is in the form of a blade conforming to the Advanced Telecommunications Computing Architecture (ATCA) standard. The platform is especially useful for telecommunications and networking applications.
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BACKGROUND OF THE DISCLOSURE
The field of the invention is truck bodies, and the invention relates more specifically to enclosed truck bodies which may either be mounted on the truck frame or on a separate trailor.
Most truck bodies have a welded steel or riveted aluminum structure which supports a relatively thin aluminum siding and top. Often an inner plywood wall or wooden slats are added to protect the thin aluminum surface from damage resulting from sources such as shifting cargo.
Although various attempts have been made to use structurally strong sidewall panels, most such attempts have failed because of numerous practical difficulties. The use of various joining elements typically results in water leakage because of the bowing or bending of the joining elements. This bowing or bending results from the movement of adjacent panels as a result of loading or as a result of the slight movement which results when a loaded truck goes over a bump in the road. Thus, the use of typical joining methods which may be perfectly satisfactory in a stationary building have proved unsatisfactory when tried in trucks. Any joining method, in order to be successful, must permit a certain amount of movement without bowing or springing so that the joint between adjacent panels will remain watertight. Similarly, the method for holding such panels at the bottom must also permit a certain amount of movement and remain watertight. The top joining method is somewhat less critical since water tends to run down and away from the upper joint. The corner joints like the panel joining rails are very critical and must provide a watertight seal in spite of the slight amount of movement that occurs during use.
SUMMARY OF THE INVENTION
The present invention is for a truck body having a plurality of structurally strong panels and having a floor to which two side rails have an upwardly oriented channel having a caulking recess extending at least about half of the height of the channel. The recess is located on the inner surface of the channel along the side of the channel which is on the exterior of the truck body. A plurality of structurally strong rectangular panels are inserted in the channels of the front and side rails. Between each adjacent panel is an upright panel-joining rail which rail has a pair of aligned opposingly faced panel receiving channels. Each channel has one flat side and an opposite side which has a recess containing an adhesive-caulking compound. The recess extends over more than one-half of the opposite side and further extends into the inner surface of the channel. A corner rail is located at the four corners of the truck body, each corner having two channels positioned at 90° from each other and having an inner narrowed web which permits a certain amount of flexibility between the two channels. Each panel has at least one caulking containing recess on an inner face thereof. Two side rails and a front rail are affixed to the top of said panels, these rails having a panel receiving channel at the lower end thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the truck body of the present invention.
FIG. 2 is an enlarged cross-sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is an enlarged cross-sectional view taken along line 3--3 of FIG. 1.
FIG. 4 is an enlarged cross-sectional view taken along line 4--4 of FIG. 1.
FIG. 5 is an enlarged cross-sectional view taken along line 5--5 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A truck body 10 is shown in perspective view in FIG. 1. The truck body may be mounted on a frame affixed to the truck or on a frame of a trailor which in turn would be affixed to a tractor. The right side of the truck body has five rectangular panels 11 through 15. Panels 11 through 15 are held by bottom rail 16 which is shown more clearly in FIG. 5. As shown in FIG. 5, bottom rail 16 has a channel made up of an inner leg 17, a bottom 18 and an outer leg 19. On the inner surface of outer leg 19 is a curved recess 20 which contains an adhesive-caulking compound 21. Adhesive-caulking compound 21 is preferably a thiokol compound. Preferably, a bead of polymer 22 is placed along the upper joint between the panels and the bottom rail 16. A polymer such as thiokol has been found satisfactory although other flexible weather resistant polymers having good adhesive properties may likewise be used.
Bottom rail 16 as the other rails described herein are made from extruded aluminum, although other materials having similar strength and flexibility may alternatively be used. Corrosion resistance is of course another requirement since the exterior surface of the rails are exposed to the elements.
A front rail 25 and a left side rail 26 are identical in cross-section to rail 16 and hold rectangular panels in the same manner. Rails 16, 25 and 26 are supported by cross bars and a frame in a conventional manner and the bottom such as bottom 18 of each rail rests on the floor of the truck body.
Between adjacent panel, an upright panel-joining rail is used to hold the panels together in a weather tight manner. These rails are indicated by reference characters 27, 28, 29 and 30. Rail 28 is shown in an enlarged cross-sectional view in FIG. 2. Rail 28 has two opposingly faced channels 31 and 32 which receive the ends of panels 13 and 12. Channel 31 has a flat inner side 33, and the inner surface of the channel is generally flat except that at one end there is a recess indicated by reference character 35. Recess 35 extends the full length of the curved outer surface 36. The tip 37 of the outer surface 36 is covered with a bead of polymer 38 which is made from the same material as bead 22. This bead is merely an additional source of protection against water leakage. The location of the recess not only along the outer surface 36 but also along a portion of inner surface 34 forms an important part of the present invention. This extension of the recess into inner surface 34 results in a particularly effective sealing mechanism. The recess 35 is filled with an adhesive-caulking compound similar in composition to adhesive-caulking compound 21. This adhesive-caulking compound is elastic and pliable and permits a certain amount of bending between panels 13 and 12 without permanently deforming rail 28. An additional bead of polymer 39 is located on the inner surface of panel 13 which also functions to prevent moisture from entering channel 31.
Similarly, the other channel, 32, has a recess 41 filled with an adhesive-caulking compound 42. Recess 41 likewise extends into a portion of the flat inner surface 43. The third side of channel 32 is flat inner side 44 which is adjacent the outer surface 45 of rail 28. Two beads of polymer 46 and 47 likewise help prevent moisture from entering into the space between the panel and the rail.
The panels of the present invention are preferably plywood panels although other materials of construction could be used. Panels of 3/4 inch plywood, 4 feet by 8 feet are readily available and are particularly useful. It is important that the panels be structurally strong since the panels themselves support the roof unlike most prior art truck bodies where the frame supports the roof. The panels of the present invention are covered with a layer of aluminum sheeting which has been laminated to the outer surface. For instance, panel 13 has an aluminum sheet 50 laminated to the outer surface of plywood 13a. Similarly panel 12 has an aluminum sheet 52 laminated to the outer surface of plywood panel 12a. This lamination may be made in a conventional manner as by spraying or otherwise coating the outer surface of the plywood panel with a contact cement and similarly coating the inner surface of the aluminum sheet with contact cement, allowing the two surfaces to dry and then pressing them together under a roller or other device to assure a tight bond. The inner surface of the panels are preferably coated with a conventional coating to prevent moisture absorbtion and warping of the panels.
One advantage of the use of aluminum coated plywood sheets is that the outer side of the truck is very smooth and may be readily lettered or painted and in general has a very neat appearance.
At each corner of the truck body there is an aluminum corner extrusion, three of which are indicated by reference character 51. Corner extrusion 51 is shown in an enlarged cross-sectional view in FIG. 3 and has two channels 53 and 54. Channel 53 has a flat inner surface 55, a panel stop 56 and a curved recess 57 which is filled with an adhesive caulking compound 58. Similarly, channel 54 has a flat inner surface 59, a stop 60 and a curved recess 61 filled with an adhesive-caulking compound 62. The joint 64 between these two channels permits a slight amount of angular movement between panel 11 and end panel 65. This amount of movement, although very slight, helps assure that the seal between the adjacent panels stays intact.
A top rail surrounds the entire truck body. The top rail has a right side 66 and a rear portion 67. As shown in FIG. 4, top rail 66 has a lower channel 68 into which panel 14 fits. Channel 68 has a generally flat inner surface 69, a stop 70 and a generally flat outer surface 71. A bead of polymer 72 helps prevent water from entering channel 68. The top rail also has a recess which contains a channel 72 which may be used to hold the wires for various lights. A shelf 73 supports a roof supporting beam or rafter 74 which in turn supports a sheet of aluminum 75 which forms the roof of the body. Roof 75 is stapled or riveted to the upper ledge 76 of rail 66. Upper ledge 76 has an upper recess 77 which helps convey any water away from the interior of the truck body.
While the upright rail members (such as rail 28) are shown as having the caulking recess on the exterior of the truck body on one side and on the interior on the other side, this is not essential. This orientation is however preferred in that it permits a thinner central wall since the two recesses are not next to each other. Furthermore, while the recesses are shown as curved recesses they could, of course, have generally flat sides and still perform the same function. The rear door 80 is preferably a conventional door having a plurality of horizontaly hinged panels which permits the door to be raised and to curve inwardly and be held under the roof of the body when the door is in an open position.
The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive; the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims therefore are intended to be embraced therein.
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A truck body made from a number of structurally strong panels. The panels are set in two side rails and a front rail and joined at their vertical intersections by panel joining rails having an inner recess for receiving a flexible adhesive-caulking compound.
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TECHNICAL FIELD OF INVENTION
[0001] The present invention relates to a solenoid-actuated control valve; more particularly to a solenoid-actuated control valve which is resistant to pressure drift over time; and even more particularly to a solenoid-actuated control valve which does not place crimp assembly loads on plastic components within the solenoid.
BACKGROUND OF INVENTION
[0002] Solenoid-actuated control valves, herein after referred to as control valves, are well known to control the flow and/or pressure of a fluid. In many applications, it may be desirable that the flow and/or pressure output of the control valve be proportional to an electric current supplied to a solenoid of the control valve. In a common control valve arrangement, the electric current supplied to the solenoid of the control valve affects the position of a supply valve member and/or an exhaust valve member relative to a supply valve seat and an exhaust valve seat respectively. The position of the supply valve member relative to the supply valve seat and/or the position of the exhaust valve member relative to the exhaust valve seat affects the fluid flow and/or pressure leaving the control valve. It is therefore important that the position of the valve members relative to the valve seats for a given electric current supplied to the solenoid does not change during the life of the control valve because if the position of the valve members relative to the valve seats is not as is expected, the flow and/or pressure leaving the control valve may not be the desired magnitude.
[0003] The solenoid of the control valve is typically enclosed in a housing that is cylindrical and made of metal. An example of such a control valve is shown in US Patent Application Publication No. US 2007/0138422 A1. During manufacturing of the control valve, at least one end of the housing is open to allow components of the solenoid to be placed within the housing. After all of the components have been placed within the housings, a cover may be placed over the open end, and the housing may be crimped or folded over the cover to retain the cover to the housing. When the housing is crimped to retain the cover, an axial load is placed on the components within the housing and the axial load on the components within the housing is maintained by the crimp connection. However, this axial load from the crimp is known to be transmitted through plastic components, such as the spool (also known as a bobbin or coil former) around which the coil of the solenoid is wound. Over time, this crimp load may cause the plastic components to creep (i.e. change in shape and position), thereby changing the position of the valve members relative to the valve seats for a given a given electric current supplied to the solenoid. As a result, the desired flow and/or pressure leaving the control valve may not be the desired magnitude for a given electric current supplied to the solenoid.
[0004] One way to address the effects of creep of the plastic components and the changing of position of the valve members relative to the valve seats over time is to use closed loop feedback. In this arrangement, the actual flow and/or pressure leaving the control valve is measured with a sensor. The sensor sends a signal indicative of the flow and/or pressure to a controller. If the signal indicates that the flow and/or pressure is not the desired magnitude, the controller can alter the electric current supplied to the solenoid until the desired flow and/or pressure reaches the desired magnitude. In this way, the effects of creep of plastic components can be overcome. However, using closed loop feedback increases the cost and complexity of the system, for example by the addition of sensors, wiring, and software.
[0005] What is needed is a control valve in which the flow and/or pressure leaving the control valve does not change over time for a given magnitude of electric current used to actuate the control valve. What is also needed is a control valve which is not affected by creeping of plastic components of the solenoid over time.
SUMMARY OF THE INVENTION
[0006] Briefly described, a valve assembly includes a hydraulic subassembly with a valve member displaceable along a valve axis for controlling at least one of flow and pressure of fluid from a fluid source to a working device. The valve assembly also includes a solenoid subassembly for selectively displacing the valve member. The solenoid subassembly includes a metallic solenoid housing having an open end distal from the hydraulic subassembly and a solenoid housing base adjacent to and connected with the hydraulic subassembly. The solenoid subassembly also includes a solenoid coil assembly disposed within the solenoid housing, the solenoid coil assembly having a coil wound around a plastic spool defining a spool bore extending through the spool. The solenoid subassembly also includes a solenoid housing cover closing off the open end of the solenoid housing and attached to the solenoid housing with a crimp connection that creates a compressive crimp force acting along the valve axis. The solenoid subassembly also includes a metallic column disposed within and passing through the spool bore, the metallic column extending from the solenoid housing base to the solenoid housing cover. The compressive crimp forces are transferred through the metallic column from the solenoid housing base to the solenoid housing cover to isolate the compressive crimp forces from plastic components.
BRIEF DESCRIPTION OF DRAWINGS
[0007] This invention will be further described with reference to the accompanying drawings in which:
[0008] FIG. 1 is a cross section of a valve assembly in accordance with the invention shown in a position which allows full pressure and/or flow from a fluid source to a working device;
[0009] FIG. 2 is an exploded isometric view of the valve assembly of FIG. 1 ; and
[0010] FIG. 3 is the cross section of FIG. 1 now with the valve assembly shown in a position which prevents fluid communication from the fluid source to the working device.
DETAILED DESCRIPTION OF INVENTION
[0011] In accordance with a preferred embodiment of this invention and referring to FIGS. 1 and 2 , solenoid-actuated control valve 10 is shown, hereinafter referred to as valve assembly 10 . Valve assembly 10 includes hydraulic subassembly 12 in fluid communication with fluid source 14 and working device 16 . Working device 16 may be, for example, a transmission clutch. Valve assembly 10 also includes solenoid subassembly 18 which is connected to hydraulic subassembly 12 and which controls the fluid communication from fluid source 14 through hydraulic subassembly 12 to working device 16 based on an electric current which is variable and which is supplied by electric current source 20 . Electric current source 20 may be, for example, an electronic controller.
[0012] Hydraulic subassembly 12 includes hydraulic subassembly housing 22 which may be made, for example, by injection molding a plastic material. Hydraulic subassembly housing 22 extends along valve axis A and includes attachment flange 24 at one axial end which is used to attach hydraulic subassembly 12 to solenoid subassembly 18 . Hydraulic subassembly housing 22 also includes inlet port 26 located in the axial end of hydraulic subassembly housing 22 which is distal from attachment flange 24 . Inlet port 26 is in constant fluid communication with fluid source 14 . Hydraulic subassembly housing 22 also includes working port 28 extending radially outward from hydraulic subassembly housing 22 . Working port 28 is in constant fluid communication with working device 16 and is in variable fluid communication with inlet port 26 based on input from solenoid subassembly 18 . Hydraulic subassembly housing 22 also includes exhaust port 30 which is in variable fluid communication with working port 28 based on input from solenoid subassembly 18 .
[0013] Hydraulic subassembly 12 also includes a supply valve member shown as ball 34 which is located within inlet port 26 and which is selectively seated and unseated with supply valve seat 36 . Supply valve seat 36 is annular, coaxial with valve axis A, and formed between working port 28 and inlet port 26 to be small in diameter than ball 34 . In order to retain ball 34 within inlet port 26 , ball retainer 38 may be provided. Ball retainer 38 may be secured, for example by press fit or welding, within an enlarged portion of inlet port 26 . A reduced diameter section of ball retainer 38 may extend further into inlet port 26 to prevent ball 34 from escaping inlet port 26 while still allowing for axial movement of ball 34 relative to supply valve seat 36 to allow for desired flow and/or pressure from fluid source 14 to working device 16 when ball 34 is not seated with supply valve seat 36 .
[0014] Hydraulic subassembly 12 is also provided with poppet rod 40 in order transfer linear motion produced by solenoid subassembly 18 to ball 34 to selectively seat and unseat ball 34 with supply valve seat 36 . Poppet rod 40 is coaxial with valve axis A and sized to extend through supply valve seat 36 such that a clearance is formed radially outward of poppet rod 40 to allow fluid communication radially between hydraulic subassembly housing 22 and poppet rod 40 from inlet port 26 to working port 28 when ball 34 is unseated with supply valve seat 36 . When ball 34 is to be unseated with supply valve seat 36 , poppet rod tip 42 contacts ball 34 and urges ball 34 away from supply valve seat 36 .
[0015] Hydraulic subassembly 12 is also provided with exhaust seat 44 which is disposed within hydraulic subassembly housing 22 axially between working port 28 and exhaust port 30 . Exhaust seat 44 is substantially disk-shaped and includes exhaust aperture 46 extending axially therethrough and coaxial with valve axis A. Exhaust aperture 46 is sized to allow poppet rod 40 to pass therethrough with sufficient radial clearance with poppet rod 40 to allow fluid communication radially between exhaust aperture 46 and poppet rod 40 from working port 28 to exhaust port 30 . Exhaust valve member 48 is fixed to poppet rod 40 and sized to be larger in diameter than exhaust aperture 46 . Poppet rod 40 is moveable based on input from solenoid subassembly 18 to allow exhaust valve member 48 to be selectively seated and unseated with exhaust seat 44 . In this way, fluid communication from working port 28 to exhaust port 30 is substantially prevented when exhaust valve member 48 is seated with exhaust seat 44 . Conversely, fluid communication from working port 28 to exhaust port 30 is permitted when exhaust valve member 48 is not seated with exhaust seat 44 . It should also be noted that fluid communication from inlet port 26 to working port 28 is permitted when exhaust valve member 48 is seated with exhaust seat 44 and that fluid communication from inlet port 26 to working port 28 is substantially prevented for a portion of the travel of poppet rod 40 in which exhaust valve member 48 is not seated with exhaust seat 44 .
[0016] Hydraulic subassembly 12 is also provided with exhaust seat retainer 50 for retaining exhaust seat 44 within hydraulic subassembly housing 22 and for guiding poppet rod 40 . Exhaust seat retainer 50 captures exhaust seat 44 axially between a shoulder within hydraulic subassembly housing 22 and the axial end of exhaust seat retainer 50 that is distal from solenoid subassembly 18 . Exhaust seat retainer 50 is press fit or otherwise fastened within hydraulic subassembly housing 22 to prevent relative movement between exhaust seat retainer 50 and hydraulic subassembly housing 22 , thereby retaining exhaust seat 44 within hydraulic subassembly housing 22 . Exhaust seat retainer 50 is cup-shaped to define exhaust chamber 52 radially outward of poppet rod 40 /exhaust valve member 48 which allows axial movement of exhaust valve member 48 within exhaust chamber 52 . Exhaust seat retainer 50 includes exhaust seat retainer aperture 54 extending axially therethrough and coaxial with valve axis A. Exhaust seat retainer aperture 54 is sized to be a clearance fit with poppet rod 40 such that poppet rod 40 is able to move axially substantially uninhibited while radial movement of poppet rod 40 is substantially prevented.
[0017] Solenoid subassembly 18 includes solenoid housing 56 which is made of a magnetic metal. Solenoid housing 56 includes a substantially cylindrical section defining solenoid housing sidewall 58 . Solenoid housing 56 also includes solenoid housing base 60 which extends radially inward from solenoid housing sidewall 58 to partially close the end of solenoid housing 56 which is proximal to hydraulic subassembly 12 . Solenoid housing base 60 may be constructed as one piece with solenoid housing sidewall 58 , for example by a metal stamping process. Solenoid housing base 60 defines solenoid housing aperture 62 extending axially through solenoid housing base 60 coaxial with valve axis A. Solenoid housing 56 also includes attachment tabs 64 which are used to retain hydraulic subassembly 12 to solenoid subassembly 18 . Attachment tabs 64 extend axially from solenoid housing sidewall 58 toward hydraulic subassembly 12 . In FIG. 2 , attachment tabs 64 are shown as phantom lines as they appear after being crimped or folded over attachment flange 24 of hydraulic subassembly housing 22 in order to retain hydraulic subassembly 12 to solenoid subassembly 18 . Attachment tabs 64 are also shown in FIG. 2 as solid lines as they would appear prior to attachment tabs 64 being crimped over to attach hydraulic subassembly 12 to solenoid subassembly 18 .
[0018] Solenoid subassembly 18 also includes spool 66 which is made of a material which does not conduct electricity, for example, plastic. Spool 66 includes spool cylinder 68 which is coaxial with valve axis A and spool bore 70 which extends axially through spool cylinder 68 coaxial with valve axis A. Spool 66 also includes spool rims 72 , 74 which extend radially outward from the ends of spool cylinder 68 . Spool rim 72 extends radially outward from the end of spool cylinder 68 which is proximal to solenoid housing base 60 while spool rim 74 extends radially outward from the end of spool cylinder 68 which is distal from solenoid housing base 60 . Electrically conductive wire is wound around spool cylinder 68 between spool rims 72 , 74 to form coil 76 which is connected to terminals 78 which are connected to electric current source 20 . Spool 66 and coil 76 together define a solenoid coil assembly.
[0019] Solenoid subassembly 18 also includes primary pole piece 80 and secondary pole piece 82 which are each made of a magnetic material. Primary pole piece 80 and secondary pole piece 82 are sized to fit within spool bore 70 such that primary pole piece 80 and secondary pole piece 82 may be inserted within spool bore 70 without restriction. Primary pole piece 80 may be disposed proximal to solenoid housing base 60 while secondary pole piece 82 may be disposed distal from solenoid housing base 60 . It should be noted that primary pole piece 80 and secondary pole piece 82 are part of the magnetic circuit of solenoid subassembly 80 which function to control the magnetic flux distribution.
[0020] Primary pole piece 80 includes primary pole piece bore 84 which extends axially through primary pole piece 80 coaxial with valve axis A. Primary pole piece bushing 86 is fixed within primary pole piece bore 84 , for example, by press fit. Primary pole piece bushing 86 is made of a non-magnetic material, for example, bronze or plastic and includes primary pole piece bushing bore 88 which extends axially through primary pole piece bushing 86 coaxial with valve axis A. Primary pole piece 80 is fixed to solenoid housing base 60 , for example, by press fit within solenoid housing aperture 62 .
[0021] Secondary pole piece 82 includes secondary pole piece bore 90 which extends axially through secondary pole piece 82 coaxial with valve axis A. Secondary pole piece bushing 92 is fixed within secondary pole piece bore 90 , for example, by press fit. Secondary pole piece bushing 92 is made of a non-magnetic material, for example, bronze or plastic and includes secondary pole piece bushing bore 94 which extends axially through secondary pole piece bushing 92 coaxial with valve axis A.
[0022] Primary pole piece 80 may be fixed to secondary pole piece 82 with alignment ring 96 . Alignment ring 96 is cylindrical and made of a non-magnetic material, for example, brass or stainless steel. Alignment ring 96 is fixed to primary pole piece 80 , for example, by press fit with primary pole piece reduced diameter section 98 . Alignment ring 96 axially abuts primary pole piece shoulder 100 which is defined by primary pole piece reduced diameter section 98 . Similarly, alignment ring 96 is fixed to secondary pole piece 82 , for example, by press fit with secondary pole piece reduced diameter section 102 . Alignment ring 96 axially abuts secondary pole piece shoulder 104 which is defined by secondary pole piece reduced diameter section 102 . Alignment ring 96 is sized to fit within spool bore 70 such that alignment ring 96 may be inserted within spool bore 70 without restriction. Alignment ring 96 is also sized to axially space primary pole piece 80 from secondary pole piece 82 .
[0023] Solenoid subassembly 18 also includes armature 106 which is at least partly disposed within secondary pole piece bore 90 in a clearance fit such that armature 106 is able to slide within secondary pole piece bore 90 without restriction and such that radial movement of armature 106 within secondary pole piece bore 90 is substantially prevented. Armature 106 is made of a magnetic material and includes armature bore 108 which extends axially through armature 106 and coaxial with valve axis A. Armature 106 may also be partially received within enlarged section 110 of primary pole piece bore 84 . Enlarged section 110 is sized to allow unrestricted movement of armature 106 within enlarged section 110 . The axial position of armature 106 along valve axis A is variable based on electric current supplied to coil 76 by electric current source 20 .
[0024] Solenoid subassembly 18 also includes connecting rod 112 which is received within primary pole piece bushing bore 88 , secondary pole piece bushing bore 94 , and armature bore 108 coaxial with valve axis A. Connecting rod 112 is sized to form a slip fit with primary pole piece bushing bore 88 and secondary pole piece bushing bore 94 such that connecting rod 112 is able to move axially without restriction and such that radial movement of connecting rod 112 is substantially prevented. Connecting rod 112 is fixed to armature 106 , for example by press fit or staking such that connecting rod 112 moves axially with armature 106 as a single unit. Connecting rod 112 includes rod spring seat 114 which is formed by a reduced diameter end of connecting rod 112 that is proximal to hydraulic subassembly 12 . The end of connecting rod 112 that is proximal to hydraulic subassembly 12 is fixed to poppet rod 40 . In this way, axial movement of armature 106 /connecting rod 112 is translated to axial movement of poppet rod 40 .
[0025] Return spring 116 radially surrounds a portion of poppet rod 40 and a portion of connecting rod 112 . Return spring 116 is disposed axially between exhaust seat retainer 50 and rod spring seat 114 to bias poppet rod 40 /connecting rod 112 /armature 106 away from hydraulic subassembly 12 .
[0026] Solenoid subassembly 18 also includes solenoid housing cover 118 made of a magnetic metal for closing the end of solenoid housing 56 which is distal from solenoid housing base 60 . Solenoid housing cover 118 includes alignment tabs 120 that extend radially outward from solenoid housing cover 118 . Alignment tabs 120 fit within solenoid housing notches 122 formed in solenoid housing sidewall 58 of solenoid housing 56 (only one solenoid housing notch 122 is visible in FIG. 2 ). Attachment tabs 124 extend axially away from solenoid housing sidewall 58 to define solenoid housing notches 122 . In FIG. 1 , attachment tab 124 is shown as a solid line as it appears after assembly and being crimped (i.e. folded over) to retain solenoid housing cover 118 . Also in FIG. 1 , attachment tab 124 is shown as a phantom line as it would appear prior to the folding or crimping operation. In FIG. 2 , attachment tabs 124 are shown only as they would appear prior to the folding or crimping operation. Solenoid housing cover 118 includes recessed section 126 which may be formed, for example, by a stamping operation. Recessed section 126 is formed with a diameter to receive a portion of secondary pole piece 82 therewithin.
[0027] After attachment tabs 124 have been crimped to retain solenoid housing cover 118 , an compressive crimp load exists on solenoid housing cover 118 along valve axis A. This crimp load is counteracted at the outer edge of solenoid housing cover 118 by solenoid housing sidewall 58 . This crimp load is also counteracted radially inward of the outer edge of solenoid housing cover 118 by a metallic column which may be formed by the combination of primary pole piece 80 , alignment ring 96 , and secondary pole piece 82 . It should be noted that if primary pole piece 80 is attached to solenoid housing base 60 by a press fit within solenoid housing aperture 62 , the force required to move primary pole piece 80 relative to solenoid housing base 60 must be greater than the axial force acting on primary pole piece 80 /alignment ring 96 /secondary pole piece 82 as a result of attachment tabs 124 being crimped over to retain solenoid housing cover 118 . In this way, the crimp load is isolated from plastic components and consequently the crimp load is not supported by any plastic components which could creep over time due to the crimp load. Creep of plastic parts over time due to the crimp load may cause a change in the position over time of poppet rod 40 /connecting rod 112 /armature 106 for a given electric current applied to coil 76 compared to the position of poppet rod 40 /connecting rod 112 /armature 106 at the same given electric current applied to coil 76 when valve assembly 10 is first manufactured.
[0028] When electric current source 20 applies an electric current of sufficient magnitude to coil 76 , a magnetic field is generated through a magnetic circuit which includes primary pole piece 80 , armature 106 , secondary pole piece 82 , solenoid housing cover 118 , and solenoid housing 56 . The magnetic field creates an attractive force between armature 106 and primary pole piece 80 , thereby causing armature 106 to move toward primary pole piece 80 and compressing return spring 116 . The magnitude that armature 106 moves may be proportional to the magnitude of electric current applied to coil 76 in order to precisely control the axial position of armature 106 . When the electric current applied to coil 76 is decreased or stopped, return spring 116 urges armature 106 in the upward direction as viewed in FIG. 1 .
[0029] In operation and referring to FIG. 1 , valve assembly 10 is shown in an operational state in which maximum flow and/or pressure is permitted to be supplied from fluid source 14 to working device 16 . This is accomplished by electric current source 20 applying a current to coil 76 sufficient to axially move armature 106 /poppet rod 40 /connecting rod 112 until exhaust valve member 48 contacts exhaust seat 44 . When this occurs, return spring 116 is compressed and ball 34 is unseated with supply valve seat 36 by poppet rod tip 42 . Ball 34 may be moved further away from supply valve seat 36 by fluid from fluid source 14 until ball 34 contacts ball retainer 38 . In this way, the maximum amount of flow and/or pressure of the fluid from fluid source 14 is applied to working device 16 . Arrows S are used to illustrate the pressure and/or flow fluid supplied by fluid source 14 .
[0030] In operation an now referring to FIG. 3 valve assembly 10 is shown in an operational state in which flow and pressure is prevented from being supplied from fluid source 14 to working device 16 . This is accomplished by stopping electric current source 20 from applying a current to coil 76 or decreasing the current to a magnitude such that return spring 116 axially urges armature 106 /poppet rod 40 /connecting rod 112 to a position that prevents poppet rod tip 42 from interfering with ball 34 from seating with supply valve seat 36 . When this occurs, exhaust valve member 48 is lifted from exhaust seat 44 to allow fluid to exit valve assembly 10 through exhaust port 30 . This allows ball 34 to seat against supply valve seat 36 by the flow and/or pressure of fluid from fluid source 14 , thereby preventing fluid communication from fluid source 14 to working device 16 . Arrows E are used to illustrate the exhaust of fluid from working device 16 to exhaust port 30 .
[0031] While not shown, it should now be understood that electric current source 20 may apply a current to coil 76 sufficient to axially move armature 106 /poppet rod 40 /connecting rod 112 to positions that are intermediate of the positions shown in FIGS. 1 and 3 . This allows some flow and/or pressure of fluid from fluid source 14 to escape to exhaust port 30 in order to decrease the flow and/or pressure of fluid supplied to working device 16 , thereby achieving a desired flow and/or pressure of fluid to working device 16 .
[0032] Valve assembly 10 has been illustrated as preventing fluid communication from fluid source 14 to working device 16 when coil 76 is not supplied with an electric current and has also been illustrated as preventing fluid communication from working device 16 to exhaust port 30 when a maximum electric current is applied to coil 76 which is commonly referred to as a “normally low” valve because the default operation (i.e. no electric current) of valve assembly 10 results in low flow and/or pressure to working device. It should now be understood that valve assembly 10 may also be configured to be a “normally high” valve by reversing the positions of primary pole piece 80 and secondary pole piece 82 and repositioning return spring 116 to urge poppet rod 40 /armature 106 /connecting rod 112 toward hydraulic subassembly 12 . This arrangement would make the default operation (i.e. no electric current) to allow maximum flow and/or pressure of fluid to working device 16 from fluid source 14 .
[0033] While solenoid subassembly 18 has been shown in the context of actuating a valve, it should now be understood that the use of solenoid subassembly 18 need not be limited to actuating valves, but may be used in other applications where linear motion generated by a solenoid is commonly used. It this way, the magnitude of linear motion produced by solenoid assembly 18 may be precisely controlled over time for a given electric current since creeping of plastic components within solenoid assembly 18 due to crimp forces is eliminated.
[0034] While this invention has been described in terms of preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.
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A valve assembly includes a hydraulic subassembly with a valve member displaceable along a valve axis for controlling flow of fluid. The valve assembly also includes a solenoid subassembly for selectively displacing said valve member. The solenoid subassembly includes a metallic solenoid housing having an open end and a solenoid housing base. The solenoid subassembly also includes a solenoid coil assembly disposed within the solenoid housing, the solenoid coil assembly having a coil wound around a plastic spool defining a spool bore extending through the spool. The solenoid subassembly also includes a metallic solenoid housing cover closing off the open end of the solenoid housing and attached to the solenoid housing with a crimp connection. The solenoid subassembly also includes a metallic column disposed within and passing through the spool bore extending from the solenoid housing base to the solenoid housing cover.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an embroidery frame supporting device which fixes an embroidery frame to a frame driving mechanism of an embroidery sewing machine.
2. Background of the Related Art
U.S. Pat. No. 4,280,420 published on July 28, 1981 discloses an embroidery sewing machine with a detachable embroidery frame. According to this specification, the embroidery frame is fixed to a driving mechanism by a supporting device which has a ferromagnetic plate and a permanent magnet.
However, the conventional supporting device does not have enough supporting force between the frame and the driving mechanism. Therefore, when a large or heavy embroidery frame is fixed to the driving mechanism by the conventional supporting device, an embroidery pattern is deformed due to the lack of the sufficient supporting force.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to obviate above conventional drawbacks.
Further, an object of the present invention is to support an embroidery frame with enough supporting force.
Furthermore, an object of the present invention is to permit easy detachment of an embroidery frame.
Yet a further object of the present invention is to support an embroidery frame with suitable supporting force in response to a characteristic of the embroidery frame.
To achieve the above objects, an embroidery frame supporting device according to the present invention comprises a frame member having at least one of a fixing screw and a ferromagnetic plate, a driving mechanism for travelling in a two dimensional plane, a carriage member for supporting the frame member and for transmitting the movement of the driving mechanism to the frame member, a yoke member fixed to the carriage member, a magnetic member fixed to the yoke member, and a recess provided on the carriage member and engaging with the fixing screw.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 is a perspective view of an embroidery sewing machine which utilizes a frame supporting device according to the present invention;
FIG. 2a is a plan view of a carriage member and a small embroidery frame according to the present invention;
FIG. 2b is a side view of a carriage member attaching a small embroidery frame according to the present invention;
FIG. 3a is a plan view of a carriage member and a large embroidery frame according to the present invention; and
FIG. 3b is a side view of a carriage member engaging with a large embroidery frame according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a driving mechanism (1) is provided on a bed (3a) of an embroidery sewing machine (3). The driving mechanism (1) includes two D.C. motors which are driven by a control circuit (not shown) of the sewing machine (3) in a synchronous manner with the up and down reciprocation of a sewing needle (not shown). One of the motors drives a carriage member (4) mounted on the driving mechanism (1) for travel on the bed (3a) along X-axis illustrated in FIG. 1. The other motor drives the entire driving mechanism (1) for travel on the bed (3a) along Y-axis which is perpendicular to the X-axis. A large embroidery frame (14) is fixed to the carriage member (4). Accordingly, when the driving mechanism (1) and the carriage member (4) are driven, the embroidery frame (14) travels on the bed (3a) along the X and Y axes.
FIG. 2a is a plan view of the carriage member (4) and a small embroidery frame (2) according to the present invention. Further, FIG. 2b is a side view of the attachment of the carriage member (4) to the small embroidery frame (2).
As shown in FIG. 2b, two guide rods (5) are inserted through the carriage member (4). The carriage member (4) travels in parallel with a surface of the bed (3a). The guide rods (5) are fixed to the driving mechanism (1).
The carriage member (4) is linked with a D.C. motor by a timing belt (not shown). The timing belt passes through a space (18) and is fixed on the carriage member (4) at a first member (4a) and a press member (13). Accordingly, when the motor is driven and the timing belt is rotated, the carriage member (4) travels along the guide rods (5).
The carriage member (4) includes the first member (4a), a second member (4b), a third member (4c), yoke plates (6) and (7), a permanent magnet (9) and the press member (13). The first member (4a), the second member (4b) and the third member (4c) are integrally formed of cast aluminum. Further, as shown in FIG. 2a, a second recess (4d) is formed on the middle of the third member (4c).
A first yoke plate (6) is fixed to a bottom surface of the second member (4b) by a screw (8). The yoke plate (6) is made of steel. A permanent magnet (9) is fixed on the yoke plate (6) by an adhesive. The permanent magnet (9) is also fixed to a side of the third member (4c).
A second yoke plate (7) is inserted between the top of the permanent magnet (9) and the third member (4c). The yoke plate (7) is fixed to the third member (4c) by two spring pins (10) and engages the permanent magnet (9). The yoke plate (7) has two small holes which have larger diameters than diameters of the spring pins (10).
Accordingly, the yoke plate (7) is capable of moving slightly with respect to the third member (4c).
The permanent magnet (9) has magnetic poles on both surfaces opposed to the yoke plates (6) and (7). Further, ends (6a) and (7a) of the yoke plates (6) and (7) project beyond a free side (9a) of the permanent magnet (9). Accordingly, when a ferromagnetic plate (12) fixed to extension portion (2a) of the frame (2) is inserted into the recess (4d) and abut yoke plates (6) and (7), the two yoke plates (6) and (7) connect the poles of the permanent magnet (9) magnetically with the ferromagnetic plate (12), so that a magnetically closed circuit is established around the permanent magnet (9). Therefore, the magnetic force of the permanent magnet (9) is used efficiently and the ferromagnetic plate (12) is strongly attracted to the yoke plates (6) and (7).
As described above, the yoke plate (7) is capable of moving slightly in the present embodiment. Therefore, when the ferromagnetic plate (12) is attracted to the yoke plates (6) and (7), the ends (6a) and (7a) of the yoke plates (6) and (7) are able to be positioned in a single plane. Accordingly, the ferromagnetic plate (12) is in close contact with both yoke plates (6) and (7).
As shown in FIG. 2a, the third member (4c) also has two elongated first recesses (11). The elongated recesses (11) open toward the same direction as the free side (9a) of the permanent magnet (9). Further, the spacing between the elongated recesses (11) is longer than the permanent magnet (9).
The small embroidery frame (2) comprises an inner ring (2c) and an outer ring (2b). A cloth to be sewn is pinched between the inner ring (2c) and outer ring (2b) and is stretched by the rings (2b) and (2c). The fixed extension portion (2a) is formed integrally with the outer ring (2b). The fixed extension portion (2a) is to be fixed to the carriage member (4).
The ferromagnetic plate (12) is fixed to the fixed extension portion (2a). The ferromagnetic plate (12) is attracted to the permanent magnet (9). As shown in FIG. 2a, the ferromagnetic plate (12) has substantially the same width as the recess (4d) provided on the third member (4c). Further, as shown in FIG. 2b, when the small embroidery frame (2) is fixed to the carriage member (4), the ferromagnetic plate (12) is inserted into the recess (4d).
As described above, when the small embroidery frame (2) is to be fixed to the carriage member (4), the position of the embroidery frame (2) is vertically set by the bed (3a) and horizontally set by the recess (4d). Then the embroidery frame (2) is attracted and fixed by the magnetic force of the permanent magnet (9).
As the size of the embroidery frame (2) becomes larger, a larger supporting force is required between the frame (1) and the carriage member (4) because of the increased mass of the embroidery frame (2). Accordingly, the large embroidery frame (14) (FIGS. 3a and 3b) is fixed to the carriage member (4) by engaging fixing screws (15) with the elongated recesses (11). The fixing screws (15) are provided on the large embroidery frame (14).
FIG. 3a is a plan view of the carriage member (4) and the large embroidery frame (14) according to the present embodiment. FIG. 3b is a side view of the carriage member (4) engaging with the large embroidery frame (14) according to the present invention.
The large embroidery frame (14) has a stay (14a) and a ring part (14b). The ring part (14b) is fixed on the stay (14a) by two screws (16). Further, the ring part (14b) comprises an inner ring (14d) and an outer ring (14e). The cloth to be sewn is pinched between the inner ring (14d) and outer ring (14e) and is stretched by the rings (14d) and (14e).
A fixed portion (14c) is formed integrally with the stay (14a). The two fixing screws (15) are provided on the fixed portion (14c) in opposition to the two elongated recesses (11). Further, as shown in FIG. 3b, nuts (17) are fixed on the fixed portion (14c) by welding. The fixing screws (15) are engaged with the nuts (17).
When the large embroidery frame (14) is to be fixed to the carriage member (4), the two fixing screws (15) are inserted into the elongated recesses (11), then the fixing screws (15) are tightened. The elongated recesses (11) are pinched between the fixing screws (15) and the fixed portion (14c). Thus, the large embroidery frame (14) is fixed to the carriage member (4).
According to the present embodiment, the large embroidery frame (14) is fixed to the carriage member (4) with a large supporting force, because the large embroidery frame (14) is fixed by the fixing screws (15). Further, an embroidery frame which is deformed or vibrated easily by the movement of the carriage member (4) can be also fixed to the carriage member (4) with enough supporting force.
According to the invention, the cloth to be sewn is mounted on the embroidery frame (2) or (14) when the frames (2) and (14) are dismounted from the embroidery sewing machine (3). Therefore, a plurality of embroidery frames (2) and (14) loaded with cloths may be provided in order to improve the operating efficiency.
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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An embroidery frame supporting device includes a frame member having either a fixing screw or a ferromagnetic plate, a driving mechanism for travelling in a two dimensional plane, a carriage member for supporting the frame members and for transmitting the movement of the driving mechanism to the frame member, a yoke member fixed to the carriage member, a magnetic member fixed to the yoke member, and a recess provided on the carriage member and engaging with the fixing screw. When a large or heavy frame member is fixed to the carriage member, the fixing screw is inserted into the recess. Thus, the large frame member is fixed to the carriage member with a suitable supporting force. Further, when a small frame member is fixed to the carriage member, the small or light frame member is attracted by the magnetic force of the magnet member. Thus, the small frame member is fixed to the carriage member with suitable supporting force.
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This application claims the benefit under 35 U.S.C. § 119(e) of prior application Ser. No. 60/175,650, filed Jan. 12, 2000.
FIELD OF THE INVENTION
This invention relates to novel benzosulfones useful as calcium channel blockers. These compounds, and related pharmaceutical compositions, are useful for treating and preventing a number of disorders such as hypersensitivity, allergy, asthma, bronchospasm, dysmenorrhea, esophageal spasm, glaucoma, premature labor, urinary tract disorders, gastrointestinal motility disorders and cardiovascular disorders.
BACKGROUND OF THE INVENTION
Thiacycloalkeno[3,2-b]pyridines are inhibitors of calcium ion uptake into smooth muscle tissue. They act to relax or prevent contraction of the tissue mediated by calcium mechanisms (Dodd et al., Drug Des. Discov. 1997 15:135-48). These compounds are active antihypertensives and bronchodilators.
Thiacycloalkeno[3,2-b]pyridines are also useful for the treatment of cardiovascular disorders, including hypertension, ischemia, angina, congestive heart failure, migraines, myocardial infarction and stroke. Such compounds are also useful for the treatment of other disorders such as hypersensitivity, allergy, asthma, dysmenorrhea, esophageal spasm, gastrointestinal motility disorders, glaucoma, premature labor and urinary tract disorders.
Dodd et al. evaluated a series of thiacycloalkeno[3,2-b]pyridines ranging in sulfone ring size from five to nine members for calcium antagonist activity. It was found that increasing the sulfone ring size from 5 to 8 members results in an in vitro potency increase of two orders of magnitude. Aromatic substitution patterns which favor tracheal effects over aortic effects were found to be 2-NO 2 and 2-Cl, 6-F. The ester side chain which was found to maximize in vivo activity was the N-benzyl-N-methyl aminoethyl moiety (Dodd et al., Drug Des. Discov. 1997,15:135-48, and Drug Des. Discov. 1993, 10:65-75).
Numerous compounds related to thiacycloalkeno[3,2-b]pyridines are known, as exemplified by the following publications. U.S. Pat. No. 5,708,177 to Straub discloses a process for the preparation of optically active ortho-substituted 4-aryl- or heteroaryl-1,4-dihydropyridines by oxidation and subsequent reduction from their opposite enantiomers. U.S. Pat. No. 5,075,440 to Wustrow et al. discloses pyrido[2,3-f][1,4]thiazepines and pyrido[3,2-b][1,5]benzothiazepines which are useful as calcium channel antagonists with cardiovascular, antiasthmatic and antibronchoconstriction activity. U.S. Pat. Nos. 4,879,384 and 4,845,225, each to Schwender and Dodd, disclose substituted thiacycloalkeno [3,2-b]pyridines which are also useful as calcium channel antagonists with cardiovascular, antiasthmatic and antibronchoconstrictor activity. U.S. Pat. Nos. 4,285,955 and 4,483,985 disclose acyclic sulfone substitution on simple dihydropyridines which possess calcium channel antagonist activity. U.S. Pat. No. 4,532,248 discloses a broad genus of dihydropyridines, including cyclic sulfones fused to a dihydropyridine nucleus. Cardiotonic activity is disclosed for this entire genus. However, these compounds are not calcium channel blockers. Finally, 10-Phenyl-2H-thiopyranol[3,2-b]quinolines are disclosed in Pagani, G. P. A., J. Chem. Soc. Perkin Trans. 2,1392 (1974).
“Soft drugs” (also known as “antedrugs”) are biologically active drugs which are metabolically inactivated after they achieve their therapeutic role at their designed site of action. The use of soft drugs, instead of their non-inactivatable analogs, avoids unwanted side effects. Soft drugs are known generally (see, for example, Biggadike et al., 2000, J. Med. Chem. 43:19-21; Lee et al., 1998, Curr. Opin. Drug Disc. Dev. 1: 235-44). However, no dihydropyridine soft drugs are known.
SUMMARY OF THE INVENTION
This invention provides novel benzosulfones as defined hereinbelow, as well as methods for making same. This invention also provides a pharmaceutical composition comprising the instant compound and a pharmaceutically acceptable carrier.
This invention further provides a method of treating a subject suffering from a disorder whose alleviation is mediated by the reduction of calcium ion influx into cells whose actions contribute to the disorder, which method comprises administering to the subject a therapeutically effective dose of the instant pharmaceutical composition.
This invention still further provides a method of inhibiting in a subject the onset of a disorder whose alleviation is mediated by the reduction of calcium ion influx into cells whose actions contribute to the disorder, which method comprises administering to the subject a prophylactically effective dose of the instant pharmaceutical composition.
Finally, this invention provides an apparatus for administering to a subject the instant pharmaceutical composition, comprising a container and the pharmaceutical composition therein, whereby the container has a means for delivering to the subject a therapeutic and/or prophylactic dose of the pharmaceutical composition.
DETAILED DESCRIPTION OF THE INVENTION
This invention provides a compound of Formula I,
or a pharmaceutically acceptable salt thereof, wherein
(a) R 1 , R 2 , R 3 , R 4 and R 5 are independently selected from the group consisting of H, OH, halogen, cyano, NO 2 , alkyl, C 1-8 alkoxy, C, 1-8 alkylsulfonyl, C 1-4 carboalkoxy, C, 1-8 alkylthio, difluoromethoxy, difluoromethylthio, trifluoromethyl, and oxadiazole (formed by R 1 and R 2 );
(b) R 6 is selected from the group consisting of H, C 1-5 straight or branched alkyl, alkylamine, aryl, 3-piperidyl, N-substituted 3-piperidyl, and N-substituted 2-pyrrolidinyl methylene, wherein
said N-substituted 3-piperidyl and said N-substituted 2-pyrrolidinyl methylene may be substituted with C 1-8 straight or branched chain alkyl or benzyl, and said substituted alkyl may be substituted with C 1-8 alkoxy, C 2-8 alkanoyloxy, phenylacetyloxy, benzoyloxy, hydroxy, halogen, p-tosyloxy, mesyloxy, amino, carboalkoxy or NR′R″, wherein
(i) R′ and R″ are independently selected from the group consisting of H, C 1-8 straight or branched alkyl, C 3-7 cycloalkyl, phenyl, benzyl, and phenethyl, or (ii) R′ and R″ together form a heterocyclic ring selected from the group consisting of piperidino, pyrrolidino, morpholino, thiomorpholino, piperazino, 2-thieno, 3-thieno, and an N-substituted derivative of said heterocyclic rings, said N-substituted derivative being substituted with H, C 1-8 straight or branched alkyl, benzyl, benzhydryl, phenyl and/or substituted phenyl (substituted with NO 2 , halogen, C 1-8 straight or branched chain alkyl, C 1-8 alkoxy and/or trifluoromethyl); and
(c) R 7 is selected from the group consisting of H, amino, alkyl, aryl, trifluoromethyl, alkoxymethyl, 2-thieno and 3-thieno.
The following compounds are embodiments of the present invention:
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(2-chlorophenyl)-1,4,6,7-tetrahydro-2-methyl-, methyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(2,3-dichlorophenyl)-1,4,6,7-tetrahydro-2-methyl-, 2-[methyl(phenylmethyl)amino]ethyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(2,3-dichlorophenyl)-1,4,6,7-tetrahydro-2-methyl-, methyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 1,4,6,7-tetrahydro-2-methyl-4-(pentafluorophenyl)-, methyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 1,4,6,7-tetrahydro-2-methyl-4-(2-nitrophenyl)-, methyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(3-chlorophenyl)-1,4,6,7-tetrahydro-2-methyl-, methyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(2,3-dichlorophenyl)-1,4,6,7-tetrahydro-2-methyl-, 2-[methyl(2-thienylmethyl)amino]ethyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 1,4,6,7-tetrahydro-2-methyl-4-(3-nitrophenyl)-, methyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(2-chloro-6-hydroxyphenyl)-1,4,6,7-tetrahydro-2-methyl-, methyl ester, 5,5-dioxide;
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(2-chlorophenyl)-1,4,6,7-tetrahydro-2-methyl-, 2-[methyl(2-thienylmethyl)amino]ethyl ester, 5,5-dioxide; and
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(2-chlorophenyl)-1,4,6,7-tetrahydro-2-methyl-, 2-[methyl(phenylmethyl)amino]ethyl ester, 5,5-dioxide.
This invention also provides soft drug analogs of the compounds of Formula I. These soft drugs are characterized by a chemically labile moiety bound to the ester group in turn bound to the dihydropyridine ring structure. The soft drugs permit the instant drugs to exert their effect locally, and to subsequently be metabolized in the blood stream, thereby reducing unwanted systemic effects (e.g. low blood pressure). Use of such soft drug analogs permits the administration of greater doses of the claimed dihydropyridine compounds without subjecting the subject to intolerable levels of unwanted systemic effects.
Specifically, this invention provides compounds of Formula II,
or a pharmaceutically acceptable salt thereof, wherein
(a) R 1 , R 2 , R 3 , R 4 and R 5 are independently selected from the group consisting of H, OH, halogen, cyano, NO 2 , alkyl, C 1-8 alkoxy, C 1-8 alkylsulfonyl, C 1-4 carboalkoxy, C 1-8 alkylthio, difluoromethoxy, difluoromethylthio, trifluoromethyl, and oxadiazole (formed by R 1 and R 2 );
(b) R 7 is selected from the group consisting of H, amino, alkyl, aryl, trifluoromethyl, alkoxymethyl, 2-thieno and 3-thieno; and
(c) R 8 is selected from the group consisting of -alkyl-OH, alkylamine, lactone, cyclic carbonate, alkyl-substituted cyclic carbonate, aryl-substituted cyclic carbonate, -aryl-C(O)OR′″, -alkyl-aryl-C(O)OR′″, -alkyl-OC(O)R′″, -alkyl-C(O)R′″, -alkyl-C(O)OR′″, -alkyl-N(R″)C(O)R′″, and -alkyl-N(R″″)C(O)OR′″, wherein
R′″ and R″″ are independently selected from the group consisting of hydrogen, amino, alkyl, aryl, aryl-fused cycloalkyl and heterocyclyl, the amino, alkyl, aryl, aryl-fused cycloalkyl and heterocyclyl being optionally substituted with halogen, cyano, NO 2 , lactone, amino, alkylamino, aryl-substituted alkylamino, amide, carbamate, carbamoyl, cyclic carbonate, alkyl, halogen-substituted alkyl, arylalkyl, alkoxy, heterocyclyl and/or aryl (the aryl being optionally substituted with OH, halogen, cyano, NO 2 , alkyl, amino, dimethylamino, alkoxy, alkylsulfonyl, C 1-4 carboalkoxy, alkylthio and/or trifluoromethyl).
Each of the embodiments of the compound of Formula I set forth above is also contemplated as an embodiment of the compound of Formula II. In addition, in one embodiment of Formula II, R 7 is methyl and R 1 , R 2 , R 3 , R 4 , and R 5 are independently selected from hydrogen, halogen, trifluoromethyl and NO 2 . In another embodiment of Formula II, R 8 is selected from the group consisting of -alkyl-OH, alkylamine, lactone, cyclic carbonate, alkyl-substituted cyclic carbonate, aryl-substituted cyclic carbonate, -aryl-C(O)OR′″, -alkyl-aryl-C(O)OR′″, -alkyl-C(O)R′″, -alkyl-N(R″)C(O)R′″, and -alkyl-N(R″″)C(O)OR′″. More particularly, R 8 is selected from the group consisting of —(CH 2 ) 2 OC(O)CH(CH 2 CH 3 ) 2 , —(CH 2 ) 2 OC(O)CH(CH 3 ) 2 , —(CH 2 ) 2 OC(O)PH—OCH(CH 3 ) 2 , —(CH 2 OC(O)CH 2 N(CH 3 )CH 2 PH, —CH 2 OC(O)CH 2 —PH—N(CH 3 ) 2 and —CH 2 OC(O)CH(CH 2 ) 6 .
Unless specified otherwise, the term “alkyl” refers to a straight, branched or cyclic substituent consisting solely of carbon and H with no unsaturation. Alkyl may be substituted by, for example, OH, halogen, cyano, NO 2 , alkyl, C 1-8 alkoxy, C 1-8 alkylsulfonyl, C 1-4 carboalkoxy, and C 1-8 alkylthio. The term “alkoxy” refers to O-alkyl where alkyl is as defined. Aryl substituents include, for example, phenyl, naphthyl, diphenyl, fluorophenyl, difluorophenyl, benzyl, benzoyloxyphenyl, carboethoxyphenyl, acetylphenyl, ethoxyphenyl, phenoxyphenyl, hydroxyphenyl, carboxyphenyl, trifluoromethylphenyl, methoxyethylphenyl, acetamidophenyl, tolyl, xylyl, dimethylcarbamylphenyl and the like. “Ar” may be aryl or heteroaryl. The term “heterocyclyl”, “heterocycle” or “heterocyclic residue” represents a single or fused ring or rings having at least one atom other than carbon as ring member, e.g. pyridine, pyrimidine, oxazoline, pyrrole, imidazole, morpholine, furan, indole, benzofuran, pyrazole, pyrrolidine, piperidine, thiophene, and benzimidazole. Illustrative alkylamines include —(CH 2 ) 2 N(Me)CH 2 (Ar) such as (CH 2 ) 2 N(Me)CH 2 (PH), —CH 2 CH 2 —N(Me)—CH 2 (heteroaryl) and
The symbol “Ph” or “PH” refers to phenyl. The term “halo” means fluoro, chloro, bromo or iodo. A “dehydrating agent,” which is used in a solvent such as CH 2 Cl 2 or toluene, includes but is not limited to sulfuric acid and acetic anhydride. “Independently” means that when there are more than one substituent, the substitutents may be different.
The compounds of the instant invention are asymmetric in the dihydropyridine ring at the 4-position and thus exist as optical antipodes. As such, all possible optical isomers, antipodes, enantiomers, and diastereomers resulting from additional asymmetric centers that may exist in optical antipodes, racemates and racemic mixtures thereof are also part of this invention. The antipodes can be separated by methods known to those skilled in the art such as, for example, fractional recrystallization of diastereomeric salts of enantiomerically pure acids. Alternatively, the antipodes can be separated by chromatography in a Pirkle-type column.
As used herein, the phrase “pharmaceutically acceptable salt” means a salt of the free base which possesses the desired pharmacological activity of the free base and which is neither biologically nor otherwise undesirable. These salts may be derived from inorganic or organic acids. Examples of inorganic acids are hydrochloric acid, nitric acid, hydrobromic acid, sulfuric acid, and phosphoric acid. Examples of organic acids are acetic acid, propionic acid, glycolic acid, lactic acid, pyruvic acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, methyl sulfonic acid, salicyclic acid and the like.
The instant compounds can be prepared using readily available starting materials and reaction steps well known in the art (Edema et al. J. Org. Chem. 58: 5624-7, 1993; Howard et al., J. Amer. Chem. Soc. 82:158-64, 1960).
This invention also provides a pharmaceutical composition comprising the instant compound and a pharmaceutically acceptable carrier.
Pharmaceutical compositions containing a compound of the present invention as the active ingredient in intimate admixture with a pharmaceutical carrier can be prepared according to conventional pharmaceutical techniques. The carrier may take a wide variety of forms depending on the form of preparation desired for administration, such as systemic administration including but not limited to intravenous, oral, nasal or parenteral. In preparing the compositions in oral dosage form, any of the usual pharmaceutical carriers may be employed, such as water, glycols, oils, alcohols, flavoring agents, preservatives, coloring agents, syrup and the like in the case of oral liquid preparations (for example, suspensions, elixirs and solutions), and carriers such as starches, sugars, diluents, granulating agents, lubricants, binders, disintegrating agents and the like in the case of oral solid preparations (for example, powders, capsules and tablets).
In one embodiment, the compounds of the instant invention are administered by inhalation. For inhalation administration, the compounds can be in a solution intended for administration by metered dose inhalers, or in a form intended for a dry powder inhaler or insufflator. More particularly, the instant compounds can be conveniently delivered in the form of an aerosol spray from a pressurized container, a pack or a nebuliser with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. The dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges made of a pharmaceutically acceptable material such as gelatin for use in an inhaler or insulator can be formulated to contain a powder mix of the compound and a suitable powder base such as lactose or starch.
Because of their ease of administration, tablets and capsules represent an advantageous oral dosage unit form wherein solid pharmaceutical carriers are employed. If desired, tablets can be sugar-coated or enteric-coated by standard techniques. For parenterals, the carrier will usually comprise sterile water, though other ingredients to aid solubility or to act as preservatives can be included. Injectable suspensions can also be prepared, wherein appropriate liquid carriers, suspending agents and the like are employed.
The instant compounds can also be administered in the form of an aerosol, as discussed above.
The instant pharmaceutical composition can contain a per dosage unit (e.g., tablet, capsule, powder, injection, teaspoonful and the like) from about 0.001 to about 100 mg/kg, and preferably from about 0.01 to about 20 mg/kg of the instant compound.
The compounds of the present invention inhibit the uptake of calcium ions into smooth muscle cells, and therefore act to relax or prevent calcium ion-mediated contraction of smooth muscle tissue.
Thus, this invention further provides a method of treating a subject suffering from a disorder whose alleviation is mediated by the reduction of calcium ion influx into cells whose actions contribute to the disorder, which method comprises administering to the subject a therapeutically effective dose of the instant pharmaceutical composition. By way of example, in a subject suffering from asthma, the subject's airways are constricted due to inflammation of airway smooth muscle cells (“SMC's”). Reducing the calcium influx into the SMC's, whose action (i.e., inflammation) contributes to the disorder, would be expected to alleviate the disorder.
This invention still further provides a method of inhibiting in a subject the onset of a disorder whose alleviation is mediated by the reduction of calcium ion influx into cells whose actions contribute to the disorder, which method comprises administering to the subject a prophylactically effective dose of the instant pharmaceutical composition.
In one embodiment, the disorder is selected from the group consisting of hypersensitivity, allergy, asthma, bronchospasm, dysmenorrhea, esophageal spasm, glaucoma, premature labor, a urinary tract disorder, a gastrointestinal motility disorder and a cardiovascular disorder. In the preferred embodiment, the disorder is asthma. The cardiovascular disorder can be, for example, hypertension, ischemia, angina, congestive heart failure, myocardial infarction or stroke.
As used herein, “treating” a disorder means eliminating or otherwise ameliorating the cause and/or effects thereof. “Inhibiting” the onset of a disorder means preventing, delaying or reducing the likelihood of such onset.
The term “subject” includes, without limitation, any animal or artificially modified animal. In the preferred embodiment, the subject is a human.
Methods are known in the art for determining therapeutically and prophylactically effective doses for the instant pharmaceutical composition. The effective dose for administering the pharmaceutical composition to a human, for example, can be determined mathematically from the results of animal studies.
This invention further provides an apparatus for administering to a subject the instant pharmaceutical composition, comprising a container and the pharmaceutical composition therein, whereby the container has a means for delivering to the subject a therapeutic and/or prophylactic dose of the pharmaceutical composition. In the preferred embodiment, the apparatus is an aerosol spray device for treating and/or preventing asthma via topical respiratory administration.
Finally, this invention provides a process for preparing the compound of Formula I
which process comprises reacting compound 1a with compounds of Formulae 1b and 1c to form the corresponding compound of Formula 1d.
This invention will be better understood by reference to the Experimental Details that follow, but those skilled in the art will readily appreciate that these are only illustrative of the invention as described more fully in the claims which follow thereafter. Additionally, throughout this application, various publications are cited. The disclosure of these publications is hereby incorporated by reference into this application to describe more fully the state of the art to which this invention pertains.
EXPERIMENTAL DETAILS
A. Schemes and Syntheses
The compounds of Formula I can be prepared in accordance with the following general procedures outlined in Scheme I. The starting materials are all well known and readily available in the art (Synthesis of 1,3,5,6-tetrahydro-2H-4,1-benzothiazocin-2-one, Nair et al., Indian J. Chem., Sect. B (1980), 19B(9), 765-6. CODEN: IJSBDB, ISSN: 0376-4699. CAN 94:121488 AN 1981:121488 CAPLUS).
Procedures for making dihydropyrides are well documented in the art as shown in Eistert et al. (Chem. Ber. 110, 1069-1085, 1977), G. A. Pagani (J. Chem. Soc., Perkin Trans. 2, 1392-7, 1974), Mason et al. (J. Chem. Soc. (C) 2171-76, 1967), E. A. Fehnel (J. Amer. Chem. Soc. 74,1569-74, 1952), and M. Seiyaku (Japan Patent Application No. 58201764, 1984).
The compounds of Formula II can be made in accordance with Scheme II, wherein R 1-8 are as described above, preferably in the presence of K 2 CO 3 or CsCO 3 in an organic solvent such as dimethylformamide (DMF).
The compounds of Formula II may also be made in accordance with Scheme III, wherein R 1-8 are as described above, preferably in the presence of formic acid or NaOH (aq), respectively.
The Examples below describe in greater detail the chemical syntheses of representative compounds of the present invention. The rest of the compounds disclosed herein can be prepared similarly in accordance with one or more of these methods. No attempt has been made to optimize the yields obtained in these syntheses, and it would be clear to one skilled in the art that variations in reaction times, temperatures, solvents, and/or reagents could be used to increase such yields.
Table 1 below sets forth the mass spectra data, the inhibition of nitrendipine binding and inhibition of calcium-dependent smooth muscle contraction for the instant compounds tested.
TABLE 1
Molecular Weight, Mass Spectra Data and
Calcium Channel Antagonist Activity for Compounds 1-11
Formula Ia
Nitrendipine
Compound
Mass
Binding Assay
No.
R 1
R 2
R 3
R 4
R 5
R 6
Mol. Wt.
Spectroscopy
IC 50 nM
1
H
H
H
H
Cl
Me
429.92
M + H =
430
612
2
H
H
H
Cl
Cl
(CH 2 ) 2 N(CH 3 )CH 2 Ph
597.56
M + H =
597
118
3
H
H
H
Cl
Cl
Me
464.37
M + H =
464
38
4
F
F
F
F
F
Me
485.43
M + H =
486
261
5
H
H
H
H
NO 2
Me
440.47
M + Na =
463
1900
6
H
H
H
Cl
H
Me
429.92
M + H =
430
337
7
H
H
H
Cl
Cl
603.59
M + H =
603
38
8
H
H
H
NO 2
H
Me
440.47
M + Na =
463
261
9
Cl
H
H
H
OH
Me
445.92
M + Na =
468
1300
10
H
H
H
H
Cl
(CH 2 ) 2 N(CH 3 )CH 2 Ph
569.14
M + H =
569
99
11
Cl
H
H
H
H
(CH 2 ) 2 N(CH 3 )CH 2 Ph
563.1169
M + H =
563
453
Example 1
[3]Benzothiepino[1,2-b]pyridine-3-carboxylic acid, 4-(2,3-dichlorophenyl)-1,4,6,7-tetrahydro-2-methyl-, 2-[methyl(phenylmethyl)amino]ethyl ester, 5,5-dioxide
Compound 2 was prepared following Scheme II above. The details of the preparation are as follows:
A solution of 0.37 g (1.76 mmoles) of the benzoketosulfone, 0.31 g (1.76 mmoles) of 2,3-dichlorobenzaldehyde and 0.44 g (1.76 mmoles) of 2-(N-Benzyl-N-methylamino)ethyl-3-aminocrotonate in 5 ml of dioxane was refluxed 18 hours. The reaction was cooled to room temperature, diluted with 100 ml of ethyl acetate and washed 2×60 ml water, dried over MgSO 4 , filtered, and concentrated in vacuo to give a yellow oil that solidified from diethyl ether to give 0.4224 g of the dihydropyridine as an off-white solid.
B. Assays
Example 2
Assay for Inhibition of Nitrendipine Binding
Female, New Zealand white rabbits (1-2 kg) are sacrificed by cervical dislocation, and the heart is immediately removed, cleaned and chopped into small pieces. The tissue is homogenized in 5×times volume of 0.05M Hepes buffer, pH 7.4. The homogenate is centrifuged at 4000 g for 10 minutes, and the supernatant is re-centrifuged at 42,000×g for 90 minutes. The resulting membrane pellet is resuspended (0.7 ml/g weight) in 0.05M Hepes, pH 7.4 and stored at 70° C. until used. Each tube of the binding assay contains 3 H-nitrendipine (0.05-0.50 nM), buffer, membranes (0.10 ml), and test compound in a total volume of 1.0 ml. After 90 minutes at 4° C., the bound nitrendipine is separated from the unbound by filtration on Whatman GF/C filters. After rinsing, the filters are dried and counted in a liquid scintillation counter.
Non-specific binding of 3 H-nitrendipine (that amount bound in the presence of excess unlabelled nitrendipine) is subtracted from the total bound to obtain specifically bound radiolabeled nitrendipine. The amount of specifically bound nitrendipine in the presence of a test compound is compared to that amount bound in the absence of a compound. A percent displacement (or inhibition) can then be calculated.
Example 3
Test for Inhibition of Calcium-Dependent Smooth Muscle Contraction
The trachea and the aorta from dogs sacrificed by excess KCl injection are stored overnight at 4° C. in oxygenated Krebs-Henseleit buffer. Tracheal rings, one cartilage segment wide (5-10 mm), are cut starting from the bronchial end. Rings of aorta tissue of the same width are also prepared. After cutting the cartilage, the trachealis muscle tissue and the aorta tissue are suspended in oxygenated Krebs-Henseleit buffer at 37° C. in a 25 ml tissue bath. After a 60-minute equilibration period, the tissues are challenged with 10 μM carbachol. After 5 minutes, the tissues are rinsed and allowed to rest 50 minutes. The tissues are then challenged with 50 mM KCl and, after 30 minutes, the contractions are quantitated. The tissues are then rinsed and re-equilibrated for 50 minutes. Test compounds are then added for 10 minutes, and the tissue is rechallenged with 50 mM KCl. After 30 minutes, the contraction is recorded. A percent inhibition of smooth muscle contraction can then be calculated.
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This invention provides novel benzosulfones of the following formulae:
These compounds are useful as calcium channel antagonists with cardiovascular, antiasthmatic and antibronchoconstriction activity. Thus, this invention also provides pharmaceutical compositions, as well as methods, for preventing and treating disorders such as hypersensitivity, allergy, asthma, bronchospasm, dysmenorrhea, esophageal spasm, glaucoma, premature labor, urinary tract disorders, gastrointestinal motility disorders and cardiovascular disorders.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to boats and watercraft and, more particularly, concerns an improved drain assembly for draining water out of interior compartments of boats and watercraft while preventing water from entering the interior compartment when the watercraft is positioned in the water.
2. Description of the Related Art
Boating is a very popular hobby within the United States. Each year thousands of people take speedboats, sailboats, personal watercraft and the like out onto lakes and rivers and oceans in this country. As these watercraft are operated, water often accumulates in interior compartments of the boat. Further, boat operators will often clean these interior compartments which can also result in accumulations of water within the interior compartments of the boat. Consequently, drains and drain valves are often installed in the interior compartment of the boats so that water accumulated therein can be drained outside of the boat.
For example, in a typical speedboat, a drain assembly drains water from the passenger compartment through the stern wall of the boat to the exterior of the boat. The drain assembly generally consists of a hole through the stern wall of the boat that is plugged at one end. When the boat operator wishes to drain water out of the boat, the boat operator simply removes the plug and the water in the passenger compartment then drains through the drain assembly. Typically, the plug is a screw in plug that is screwed into threads that are formed in an interior passage of the drain assembly.
One problem associated with drain assemblies of the prior art is that the boat operator may forget to replace the plug after draining the water out of the interior compartment of the boat. For example, it is common for boat operators to open the drains after the boat has been placed on the trailer to allow the water to drain out of the interior compartments after the boat has been removed from the water. If the boat operator forgets to replace the plug, water can then enter the interior compartments of the boat the next time the boat is positioned in the water. In fact, water can enter through the drain in sufficient quantities that the boat can sink and, in this country, literally hundreds of boats are lost each year as a result of this occurrence.
One solution to this problem is a one-way drain assembly that incorporates a flapper valve. This device includes an aperture that extends through a wall of the boat wherein a valve member is mounted within the aperture in a pivoting fashion. Preferably, the valve member can only pivot so as to open the aperture in response to water flowing from the boat compartment to the exterior of the boat. Further, the valve member is configured so that when water is flowing from the exterior of the boat into the interior of the boat, the valve member closes off the aperture and prevents the water from entering the boat.
While the flapper type drain valve reduces the likelihood of water entering the interior compartments of the boat after the boat operator has failed to reinstall a plug, these devices suffer from some problems. In particular, these devices are typically made of a plastic that degrades as a result of exposure to UV light. Consequently, sunlight often damages these devices to a point where the valve member breaks and does not close off the aperture when needed. Further, these devices are also exposed to oil and other foreign matter within the water which inhibits the correct pivoting motion of the flapper valve member to the point where the valve member does not adequately seal the boat. For example, the foreign matter may cause the flapper to get stuck in a fixed position which either inhibits proper operation of the drain or allows water to flow through the drain into the boat.
Hence, even though the flapper-type drain valves represent an improvement over the standard drains that simply incorporate a plug, it still suffers from serious shortcomings in its ability to prevent water from entering interior compartments of the boat when the boat is positioned in a body of water.
From the foregoing, it should be apparent that there is a need for an improved drain valve for boats that will prevent water from entering the boat when a plug has failed to be inserted into the drain valve.
SUMMARY OF THE INVENTION
The aforementioned needs are satisfied by the improved drain valve assembly of the present invention which is comprised of a drain valve assembly that can be positioned within an opening in a wall of the boat wherein the assembly defines a central opening or passageway that extends through the wall of the boat. The central passageway includes a reduced aperture portion that has a cross-sectional area which is less than the cross-sectional area of the central passageway. A ball is positioned within the central passageway and is captured therein so as to be positioned adjacent the reduced aperture. Preferably, the ball is captured within the central passageway in a position wherein it floats such that when water is flowing through the reduced aperture from an interior compartment of the boat to the exterior of the boat, the ball is urged away from the reduced aperture so that water can flow through the reduced aperture and the central passageway of the assembly. Conversely, when water is flowing from the exterior of the boat into the interior of the boat, the ball is then urged into the reduced aperture thereby inhibiting the flow of water from the exterior of the boat to the interior of the boat through the central passageway.
It will be appreciated that the improved drain valve assembly of the present invention inhibits water flow from the exterior of the boat into an interior compartment through the use of a free-floating ball that is captured within the central passageway of the drain valve. The use of the floating ball reduces the likelihood of failure of the valve as there are no pivoting members which can be broken by repeated use and fatigue. Further, the floating ball is also less likely to be stuck by oil or some other foreign matter in a fixed position. Hence, the assembly is configured to prevent water from flowing into the boat or watercraft when the boat or watercraft is positioned in the water. These and other objects of the present invention will become more fully apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view of a preferred embodiment of a improved drain valve;
FIG. 2 is a side sectional view of the improved drain valve of FIG. 1 mounted in a wall of a boat; and
FIGS. 3A and 3B are reproductions of photographs of the components of the improved drain valve of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made to the drawings wherein like numerals refer to like parts throughout. Referring initially to FIGS. 1 and 2, the components of an improved drain valve assembly 100 of the preferred embodiment will be described. In particular, the improved drain valve 100 is configured to be mounted in a wall 102 of the boat between an interior compartment 104 of the boat and the exterior of the boat 106 . The drain valve assembly 100 includes an exterior opening 110 that is surrounded by an annular flange 112 that is designed to be positioned about the outer surface 108 of the boat wall 102 . The improved drain valve assembly 100 also defines a central opening or passageway 120 that extends from the exterior opening 110 inward into an interior opening 122 that is positioned adjacent an inner surface 124 of the boat wall 102 . Preferably, the improved drain valve assembly 100 is mounted so that the interior opening 122 is positioned adjacent a floor or bottom surface 126 of an interior compartment 104 of the boat so that water that accumulates in the interior compartment 104 can enter the opening 122 and flow through the passageway 120 to the exterior opening 110 of the drain valve 100 so that the water within the interior compartment 104 can drain to the exterior 106 of the boat.
Positioned within the central aperture 120 is an annular lip 130 that extends inward from the interior walls of the central passageway 120 so as to define a reduced aperture 132 within the central passageway 120 . Further, a pin 134 is positioned so as to extend through the center of the central passageway 120 of the drain valve assembly 100 so as to define a capture area 136 within the central passageway 120 that is bounded by the interior walls of the central passageway 120 , the annular lip 130 and the pin 134 . A ball 140 (shown in phantom) is preferably positioned within the capture area 136 of the central aperture and the ball 140 is dimensioned so that the cross-sectional area of the ball 140 is greater than the cross-sectional area of the reduced aperture 132 but is less than the cross-sectional area of the central passageway 120 . The ball 140 is thereby free to float within the capture area 136 when water is flowing through the central passageway 120 .
Specifically, when water is flowing from the interior compartment 104 of the boat to the exterior 106 of the boat through the central passageway 120 , the ball 140 is urged towards the pin 134 and away from the reduced opening 132 . Hence, water can freely flow from the interior compartment 104 through the central passageway to the exterior of the boat thereby draining the boat. Alternatively, when water is flowing from the exterior 106 of the boat through the passageway 120 towards the interior compartment 104 , the ball 140 is urged by the resulting water pressure into the reduced opening 132 so that the ball 140 is seated within the reduced opening 132 to thereby prevent water from flowing into the interior compartment 104 of the boat. In the preferred embodiment, the inner edges 150 of the reduced opening 132 are angled so that the ball 140 can be flushly positioned within the opening 132 to form a generally watertight seal.
Hence, the improved drain valve of the preferred embodiment prevents water from flowing into the interior compartment 104 of the boat by the use of a free-floating ball that is captured within the central passageway that occludes a reduced aperture within the passageway when water is flowing inward into the boat. Consequently, when the boat operator fails to plug the drain valve opening 110 , water is still prevented from flowing into the interior compartment of the boat. However, the floating ball permits water to freely flow from the interior compartment 104 outward to the exterior of the boat as the ball simply floats with the water current and allows the water to flow outward.
FIGS. 3A and 3B are photographs which illustrate the drain valve 100 and a plug 160 that is designed to be mounted in the exterior opening 110 of the drain valve. In particular, the plug 160 is threaded and matching threads (not shown) are formed in the interior surfaces of the central aperture 120 so that the plug can be screwed into the opening thereby preventing water from flowing through the central aperture 120 of the improved drain 100 . The plug 160 is comprised of a threaded section 162 and a handle section 164 that is separated by a flange 166 .
To install the improved drain assembly 100 of the preferred embodiment, there must be a hole drilled through the wall of the boat that matches the diameter of the cylindrical portion 113 (FIG. 1) of the assembly 100 . The drain assembly 100 is then inserted through the hole so that the annular surface 112 rests against the exterior surface 108 of the wall. The assembly 100 is then secured via screws (not shown) that are positioned through the exterior flange 112 into the exterior surface 108 of the wall 102 of the boat.
FIG. 1 shows some dimensions of one embodiment of the assembly 100 , however, a person of ordinary skill in the art will appreciate that the dimensions can vary depending upon the size of opening in the boat, and the desired size of drain opening of the assembly. Hence, the dimensions provided in FIG. 1 are simply illustrative of one embodiment and are not meant to limit the scope of the invention. The drain assembly of the preferred embodiment is therefore configured to be able to allow for draining of the boat while still preventing water from entering into the interior compartments of the boat from the exterior surface as a result of the free-floating ball moving into a positioned wherein the passageway for water through the assembly is fully occluded. Preferably, the ball 140 is made of a material such as nylon, the pin 134 is made of stainless steel and the assembly 100 is comprised of PVC plastic or some other material that is well suited for use in water environments.
Although the foregoing description of the preferred embodiment of the present invention has shown, described, and pointed out the fundamental novel features of the invention, it will be understood that various omissions, substitutions, and changes in the form of the detail of the apparatus as illustrated as well as the uses thereof may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the invention should not be limited to the foregoing discussion, but should be defined by the appended claims.
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The present invention relates to boats and watercraft and, more particularly, concerns an improved drain assembly for draining water out of interior compartments of boats and watercraft while preventing water from entering the interior compartment when the watercraft is positioned in the water.
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BACKGROUND
[0001] 1. Field of the Disclosure
[0002] The present application generally relates to power efficient semiconductor design and, more specifically, to systems and methods for isolating power domains within integrated circuits.
[0003] 2. Description of Related Art
[0004] In many electrical devices, and especially mobile devices, power consumption of the associated integrated circuits is a major design consideration. This power consumption primarily comprises switching current that results from actively functioning circuitry and leakage current that results from inactive circuitry passively drawing power.
[0005] As integrated circuit fabrication technology continually improves and migrates to smaller geometry, the size of transistors (e.g., their minimum channel length) continues to shrink. Additionally, the threshold voltage for smaller-size transistors, which is the voltage at which a transistor turns on, is often reduced to improve operating speed. The lower threshold voltages permit reductions in the power supply voltage, which in turn may reduce power consumption. But, the lower threshold voltages and smaller-size transistors can also lead to higher leakage currents, where “leakage” currents are, e.g., currents passing through transistors that are in an “off” state. Such leakage currents generally become more problematic as integrated circuit transistors continue to scale down in size. One technique to decrease leakage current is powering off certain portions of the integrated circuit when these portions are not in use. This technique is sometimes referred to as “power collapse.”
[0006] To implement power collapse, an integrated circuit is generally organized into a plurality of power domains, where each power domain may contain one or more processing nodes, peripherals, and/or other circuitry. Power domains may have varying voltage levels from each other, and different power domains may also have asynchronous clocks. In general, each power domain is individually controllable, such that one power domain may be power collapsed during a time when other power domains remain active.
[0007] During operation, circuitry within one power domain may need to communicate with circuitry in another power domain. Often, the different power domains also correspond to different clock domains, leading to clocking concerns at the boundaries between the domains. Accordingly, systems may need a cross-domain interconnect and protocols for data to flow between different power domains. Current protocols, such as the Advanced Extensible Interface (AXI) set forth by the Advanced Microcontroller Bus Architecture (AMBA), provide signaling and certain other aspects of an interconnect.
SUMMARY
[0008] The disclosed principles provide for efficiently and methodically isolating and de-isolating a plurality of power domains from one another in a modular manner, thereby allowing processing nodes or logic within each power domain to operate autonomously when so desired.
[0009] For example, described in accordance with some aspects of the disclosure is a semiconductor device having a first processing node in a first power domain and a second processing node in a second power domain. The semiconductor device may comprise an isolation module which may comprise a buffer located between the first and second power domains. The buffer may be operable to selectively provide an electrical connection between the first and second power domains. The isolation module may further comprise a first logical isolation unit between the buffer and the first processing node as well as a second logical isolation unit between the buffer and the second processing node. The semiconductor device may further comprise an isolation sequencer operable to control the isolation module when an isolation sequence and a de-isolation sequence are performed. After the isolation sequence is performed, the first and second logical isolation units may be operable to logically isolate the buffer from the first and second processing nodes, respectively, and the buffer may be operable to provide electrical isolation between the first and second power domains. Further, after the de-isolation sequence is performed, the buffer may be operable to provide communication from the first processing node to the second processing node.
[0010] Also disclosed in accordance with some aspects of the disclosed principles is a semiconductor device having a first processing node in a first power domain and a second processing node in a second power domain, the semiconductor device comprising an isolation module operable to selectively enable communication from the first processing node to the second processing node. The isolation module may comprise means for selectively providing an electrical connection between the first and second power domains. The isolation module may further comprise means for logically isolating the means for selectively providing the electrical connection from both the first processing node and the second processing node. The semiconductor device may further comprise means for controlling the isolation module when an isolation sequence and a de-isolation sequence are performed. After the isolation sequence is performed, the means for selectively providing the electrical connection may be logically isolated from the first and second processing nodes, and electrical isolation may be provided between the first and second power domains. Further, after the de-isolation sequence is performed, the isolation module may permit communication from the first processing node to the second processing node.
[0011] Also disclosed is a non-transitory machine-readable medium having instructions stored thereon. The instructions may be executable by one or more processors for providing, by a buffer between first and second power domains, an electrical connection between the first and second power domains. The instructions may further be executable for disabling clocks associated with the first and second power domains. The instructions may further be executable for isolating, by a first logical isolation unit, the buffer from a first processing node, and isolating, by a second logical isolation unit, the buffer from a second processing node. Additionally, the instructions may further be executable for enabling, within the buffer, electrical isolation between the first and second power domains, and re-enabling the clocks associated with at least one of the first and second power domains.
[0012] Also disclosed is a method for providing isolation between a first processing node in a first power domain and a second processing node in a second power domain. The method may comprise selectively providing, by a buffer between the first and second power domains, an electrical connection between the first and second power domains. The method may further comprise disabling clocks associated with the first and second power domains. The method may further comprise isolating, by a first logical isolation unit, the buffer from the first processing node, and isolating, by a second logical isolation unit, the buffer from the second processing node. Additionally, the method may comprise enabling, within the buffer, electrical isolation between the first and second power domains, and re-enabling the clocks associated with at least one of the first and second power domains.
[0013] The disclosed principles provide a variety of benefits, especially relating to power efficiency, reliability, and modular system design. For example, according to some aspects of the disclosure, the decisions to undergo isolation and de-isolation between power domains may be decoupled from the power collapse decisions. This decoupling may simplify the design process and promote design reuse while also providing increased flexibility in power control. In further accordance with the disclosed principles, isolation may occur transparently to the processing nodes, such that a processing node in a power domain maintaining power after the isolation sequence may not need to re-configure its connection to the other processing node after isolation is removed from the connection, thereby reducing the processing overhead associated with power domain isolation and power collapse.
BRIEF DESCRIPTION OF DRAWINGS
[0014] Features and aspects of the disclosure are described in conjunction with the attached drawings, in which:
[0015] FIG. 1 shows a block diagram of a system having a plurality of power domains that may be implemented within an integrated circuit;
[0016] FIG. 2 shows a block diagram illustrating an IP block;
[0017] FIG. 3 shows a block diagram illustrating a system for managing power collapse;
[0018] FIG. 4 shows a block diagram illustrating an isolation module in accordance with the present disclosure;
[0019] FIG. 5A shows a schematic diagram illustrating an exemplary cross-domain buffer;
[0020] FIG. 5B shows a schematic diagram illustrating an exemplary electrical isolation gate;
[0021] FIG. 6 shows a block diagram of a system for providing isolation between power domains;
[0022] FIG. 7 shows a flowchart illustrating a sequence for providing isolation at a selected boundary between two power domains;
[0023] FIG. 8 shows a flowchart illustrating a sequence for removing isolation at a selected boundary between two power domains; and
[0024] FIG. 9 shows a block diagram of an exemplary wireless device having a plurality of power domains that may be selectively isolated from one another in accordance with the disclosed principles.
[0025] These exemplary figures are to provide a written, detailed description of the subject matter set forth by any claims that issue from the present application. These exemplary figures should not be used to limit the scope of any such claims.
[0026] Further, although similar reference numbers may be used to refer to similar structures for convenience, each of the various sets of features and aspects may be considered to be distinct variations. When similar reference numerals are used, a description of the common elements may not be repeated, as the functionality of these elements may be the same or similar. In addition, the figures are not to scale unless explicitly indicated otherwise.
DETAILED DESCRIPTION
[0027] FIG. 1 shows a block diagram of a system 100 having a plurality of power domains that may be implemented within an integrated circuit. The system comprises a plurality of master nodes 112 , 114 , 116 , 118 and a plurality of slave nodes 122 , 124 , 126 . The master nodes may communicate with the slave nodes and with each other via a system bus 130 . A master node may generally initiate commands and requests on the system bus 130 , whereas a slave node may generally receive commands and requests on the system bus 130 . For example, the primary processing core or cores of a device (e.g., a digital signal processing core) may serve as master nodes, whereas memory devices and peripheral units (e.g., providing USB or Bluetooth connectivity) may serve as slave nodes. The choices of master nodes and slave nodes depend on the desired topology of the end system.
[0028] The master nodes 112 , 114 , 116 , 118 , the slave nodes 122 , 124 , 126 , and the system bus 130 may be implemented in a plurality of power domains. Specifically, and as shown in FIG. 1 , the master node 112 is in a power domain 102 , the master node 114 is in a power domain 104 , the master nodes 116 and 118 and the slave nodes 122 and 124 are in a power domain 106 , and the slave node 126 is in a power domain 108 . Each power domain 102 , 104 , 106 , 108 may be connected to a clock source and to a power rail or supply. Some power domains may share a power rail or supply and/or a clock with other power domains. However, even when power domains share a power rail, they may be separately connected such that the power domains may be individually power collapsed and powered on.
[0029] The system 100 may also comprise a power controller 152 in an always-on power domain 109 . The power controller 152 may power collapse and power on any of the collapsible power domains 102 , 104 , 106 , 107 , 108 . In order to maintain control over other power domains, the always-on power domain may remain powered on whenever the system 100 receives power.
[0030] As shown in FIG. 1 , the system bus 130 may be in a separate power domain 107 from the nodes. Accordingly, the system bus 130 may be independently powered on and powered collapsed. In accordance with some aspects of the present disclosure, the system bus 130 or portions of the system bus 130 may share a power domain with one or more nodes (e.g., in the power domain 106 ). Alternatively, the system bus 130 or portions of the system bus 130 may be in the always-on power domain 109 or otherwise independent from the nodes and power domains that the system bus 130 services.
[0031] Nodes may perform certain tasks that require more than one power domain to be powered on for completion. For example, if the master node 112 needs to communicate with the slave node 126 , the power domains 102 , 107 , and 108 may require power. Accordingly, the expected activities of the nodes may determine which power domains need to remain powered on.
[0032] Before a power domain is powered collapsed, the communication channels leading into and out of that power domain may be severed, such that logic in the soon-to-be-collapsed power domain is isolated from logic in the power domains that will remain active. In conventional systems, custom “wrapper” logic is included at every interface between power domains to provide the necessary isolation. This wrapper logic may manage clock skews when the voltages of adjacent power domains are different, and the wrapper logic may also handle asynchronous clocks and level shifting. The wrapper logic is often closely integrated with the power collapse process such that it is triggered exclusively during power collapse.
[0033] In the design of integrated circuits, most subsystems and functional blocks of logic are created as modular intellectual property (IP) cores or IP blocks. This allows certain functionality to be reproduced within an integrated circuit to reduce total design costs and time. Further, IP blocks may be replicated to provide tested and proven functionality in new integrated circuit designs. Some IP blocks are hard IP blocks that describe exact mask sets to create the end circuits in and/or on a substrate. For example, a semiconductor design company may use a hard IP block of an Ethernet PHY for multiple application-specific integrated circuits (ASIC) using a common manufacturing process (e.g., 28 nm). Other IP blocks are soft IP blocks that describe certain circuits and functionality using a hardware description language such as Verilog. Soft IP blocks may be created in the form of a programmed list of connections (e.g., a net-list). Soft IP blocks have the benefit of being reusable across multiple processes. Both hard IP blocks and soft IP blocks have boundaries which also establish the interfaces by which the IP blocks can be connected to other IP blocks. The term “IP block” as used herein may refer to both soft IP blocks and hard IP blocks.
[0034] FIG. 2 shows a block diagram illustrating an IP block 202 . The IP block 202 includes a master node 214 that resides in a first power domain 204 . The IP block 202 further includes wrapper logic that extends into a second power domain 205 . The wrapper logic may comprise a cross-domain buffer 210 which bridges the first power domain 204 (e.g., master power domain) and the second power domain 205 (e.g., slave, bus, or other power domain) as well as a state control module 203 for managing control signals to the cross-domain buffer 210 and the master node 214 . As a result of the cross-domain buffer 210 being included in the IP block 202 , the master power domain 204 may be “hidden” from other nodes desiring to communicate with the master node 214 .
[0035] The boundary of the IP block 202 defines an interface by which other nodes and circuitry communicate with the circuitry inside the IP block 202 . The IP block 202 may receive a stop clock signal 220 and a reset signal 222 via the state control module 203 located at or near this interface. As the cross-domain buffer 210 is within the IP block 202 , it would be affected by these same signals 220 and 222 . Accordingly, the cross-domain buffer 210 is jointly reset with the master node 214 .
[0036] For the purposes of the following explanation, the cross-domain buffer 210 is a unidirectional buffer that outputs signals from the master node 214 via a buffer data output signal 230 and receives acknowledgement signals via a buffer acknowledgement input signal 240 . In accordance with some aspects of the disclosure, a plurality of buffers may be used, and data may flow bidirectionally between the master node 214 and nodes within or connected by the second power domain 205 .
[0037] A clamp 250 may be applied to the output signal 230 of the cross-domain buffer 210 . The clamp 250 may be an AND gate receiving a clamp signal 252 and the buffer data output signal 230 as inputs. When the clamp signal 252 is de-asserted (e.g., pulled high), the clamp 250 may allow the buffer data output signal 230 to pass as a clamp output signal 254 . When the clamp signal 252 is asserted (e.g., pulled low), the clamp 250 may become activated and may hold the clamp output signal 254 at a fixed voltage (e.g., low), independent of the buffer data output signal 230 . As such, the clamp 250 may block outgoing signals from the master node 214 , when active.
[0038] When a power controller decides to power collapse the first power domain 204 , the power controller may verify that the master node 214 is idle. Further, the clamp 250 may be activated to hold the clamp output signal 254 fixed. This may prevent any spurious outputs from the master node 214 during and after the collapse of the first power domain 204 . Additionally, one or more clock(s) associated with the first power domain 204 may be stopped via the stop clock signal 220 . Finally, the first power domain 204 may be power collapsed, e.g., by disconnecting it from a power supply.
[0039] When the power controller decides to power on the first power domain 204 , a different sequence may be used. The clock(s), if active, may be stopped via the stop clock signal 220 . This may be necessary in scenarios where the master node 214 shares a clock with other nodes that remain powered on. After the clock(s) are disabled, power may be applied to the first power domain 204 and the master node 214 . Then, electrical isolation of data lines between the first power domain 204 and the second power domain 205 may be removed. This electrical isolation may, for example, be integrated within the cross-domain buffer 210 and is not shown. At this point, the master node 214 and its associated buffer 210 may be jointly reset via a reset signal 222 . Next, the clamp 250 may be deactivated such that the buffer data output signal 230 may pass through the clamp 250 as the clamp output signal 254 . Finally, the clock(s) to the first power domain 204 may be re-enabled via de-assertion of the stop clock signal 220 .
[0040] As shown in FIG. 2 , the cross-domain buffer 210 is integrated with the master node 214 by being part of the same IP block 202 . While this may be a sufficient and convenient solution during the design stage, it reduces the flexibility of independently power collapsing the first power domain 204 and increases the complexity of the restarting sequence as well as the logic required at the power controller. This is because the power collapse logic recognizes boundary-specific conditions and factors (e.g., the clamp 250 ).
[0041] In accordance with the disclosed principles and described further below, systematic and reproducible isolation modules may be inserted at or near the boundaries between the nodes of different power domains. Further, the isolation modules may receive control signals from an isolation sequencer to enable and disable isolation, where the isolation control signals may be decoupled from power control signals (e.g., for power collapsing a power domain). By providing modular isolation, a system power manager (e.g., a power controller) may implement control without necessarily needing to know the specific details of how isolation is performed between any given set of power domains. This contrasts with the wrapper approach, where the system power manager must recognize and handle implementation details of isolation at each power domain boundary.
[0042] FIG. 3 shows a block diagram illustrating a system 300 for managing power collapse. Like the system of FIG. 1 , the system 300 may be implemented in an integrated circuit (e.g., a semiconductor device).
[0043] The system 300 includes isolation modules 360 a through 360 h (also referred to more generally as isolation modules 360 ) to manage the boundaries between different power domains. These isolation modules 360 may be designed as separate IP blocks from those having the master nodes 112 , 114 , 116 , 118 , or slave nodes 122 , 124 , 126 . The master nodes 112 , 114 , 116 , 118 and the slave nodes 122 , 124 , 126 may be individually connected to the system bus 130 in the power domain 107 through the isolation modules 360 a , 360 b , 360 c , 360 d , 360 e , 360 f , and 360 g , respectively. Isolation modules 360 may also be used to connect nodes directly to another without using the system bus 130 . For example, the isolation module 360 h may be disposed between the power domain 102 and the power domain 104 , where it may directly connect the master node 112 to the master node 114 . The isolation modules 360 may serve as ports through which data and/or control signals may cross power domains. Each isolation module 360 may provide for one or more signals to pass between two power domains, and the isolation modules 360 may pass signals either unidirectionally or bidirectionally. Additionally, a plurality of isolation modules 360 may be implemented at one or more individual boundaries between power domains.
[0044] As shown in FIG. 3 , if the master node 112 intends to communicate with the slave node 126 , data may be sent via the system bus 130 , and the data may pass through the isolation modules 360 a and 360 g . For this communication to take place, each of the power domains 102 , 107 , and 108 may be powered on, but the power domains 104 and 106 may be powered off with the isolation modules 360 b , 360 c , 360 d , 360 e , 360 f , and 360 h being active.
[0045] The isolation modules 360 may be controlled via a control signal bus 340 by an isolation sequencer 354 that may reside in an always-on power domain 109 with a power controller 152 . The isolation sequencer 354 provides logic for activating and deactivating the isolation modules 360 in the system 300 . Further, the isolation sequencer 354 may store state information of each of the isolation modules 360 , and information mapping each isolation module 360 to the power domains it affects. As such, the isolation sequencer 354 simplifies the task of power collapse by the power controller 152 , which can simply query the isolation sequencer 354 to determine which power domains have been properly isolated. If the power controller 152 determines from the isolation sequencer 354 that a power domain intended to be power collapsed is not properly isolated, the power controller 152 may issue a request to the isolation sequencer 354 to isolate that power domain.
[0046] For example, if the power controller 152 determines that the master node 114 does not need to remain active and decides to power collapse the power domain 104 , the power controller 152 may query the isolation sequencer 354 to determine if the power domain 104 is properly isolated. The isolation sequencer 354 may recognize that the isolation modules 360 b and 360 h interface with the power domain 104 . If the isolation sequencer 354 determines that the isolation modules 360 b and 360 h are activated and providing isolation, the isolation sequencer 354 may report back to the power controller 152 indicating that the power domain 104 is properly isolated. However, if the isolation sequencer 354 determines that either of the isolation module 360 b , 360 h are not isolated, the isolation sequencer 354 may alert the power controller 152 . The power controller 152 may subsequently issue a request to the isolation sequencer 354 to activate the isolation modules 360 b and/or 360 h as necessary.
[0047] In accordance with some aspects of the disclosure, the power controller 152 simply requests that the isolation sequencer 354 prepare a power domain for being power collapsed. Upon receiving a request, the isolation sequencer 354 may determine the states of the relevant isolation modules 360 and issue commands over the control signal bus 340 to activate any relevant isolation modules 360 that are not already active. Upon determining that all relevant isolation modules 360 are active, the isolation sequencer 354 may send a signal to the power controller 152 indicating that the requested power domain is fully isolated. The power controller 152 may then proceed to power collapse the power domain.
[0048] In accordance with some aspects of the disclosure, the isolation sequencer 354 stores status information about the isolation modules 360 locally in the always-on power domain 109 . This reduces or eliminates the necessity to poll the isolation modules 360 upon queries from the power controller 152 . Instead, the isolation sequencer 354 may keep track of the last command sent to each isolation module 360 . Alternatively, the isolation sequencer 354 may poll the individual isolation modules 360 over the control signal bus 340 based on the requests from the power controller 152 . This provides the benefit of reducing the amount of memory required in the always-on power domain 109 . The polling mechanism may be implemented in hardware or software. When the polling mechanism is implemented, at least in part, in software, the software may reside in a non-transitory machine-readable medium that is accessible by the isolation sequencer 354 .
[0049] In accordance with some aspects of the disclosure, the isolation sequencer 354 may also perform an isolation sequence independently from requests and decisions made by the power controller 152 . For example, if it is determined that the master node 112 will not need to communicate with other nodes for an extended period of time, the isolation sequencer may activate the isolation modules 360 a and 360 h , effectively severing the master node 112 from the other nodes and the system bus 130 . The power controller 152 may, at a later time, make the decision to power collapse the power domain 102 of the master node 112 . Alternatively, the master node 112 may continue to operate while each of the other collapsible power domains 104 , 106 , 107 , and 108 are collapsed. In some scenarios, a node in a collapsible power domain may decide to be isolated or de-isolated and may send a request to the isolation sequencer 354 over the control signal bus 340 .
[0050] The disclosed isolation system provides increased flexibility when making power collapse decisions. For example, prior implementations have not provided an effective solution for disabling a data bus while a connected processing core (e.g., in another power domain) is still active. In accordance with some aspects of the present disclosure, any power domain may be power collapsed irrespective of the states of the other power domains, as long as the proper isolation modules are active.
[0051] The following is an exemplary system that would benefit from such behavior. A sensor-processing core (e.g., a core dedicated to processing sensor input in real-time) may be coupled to external memory and other peripherals via a bus. The sensor-processing core may have sufficient internal cache to operate without requesting data over the bus for extended periods of time. Accordingly, only the sensor-processing core would need to be powered during these times. As indicated by the example of isolating the master node 112 above, the present disclosure provides for this scheme to be carried out efficiently.
[0052] While four master nodes and three slave nodes are shown in FIG. 3 , certain system implementations may have more or fewer nodes of either type. Further, other topologies may be used that do not utilize a master-slave relationship. While FIG. 3 shows a single system bus 130 , more than one bus may be selected to connect various nodes. Some nodes may interface with more than one bus. Further, some nodes may act as a master node on a first bus and as a slave node on a second bus.
[0053] While FIG. 3 shows unidirectional arrows between the nodes and the bus, it is to be understood that data may travel bidirectionally between any of the nodes and the bus. The directionality of the arrows merely indicates the direction in which control is generally applied (e.g., master nodes initiating communication with and/or requesting information from slave nodes).
[0054] FIG. 4 shows a block diagram illustrating an isolation module 360 in accordance with the present disclosure. The isolation module 360 may comprise a cross-domain buffer 410 for passing data through a power domain boundary 420 , which may also be a clock boundary 420 . The cross-domain buffer 410 may, for example, be implemented as an asynchronous First-In-First-Out (FIFO) buffer 410 . However, other types of buffers may be used, depending, at least in part, on the nature of the boundary 420 . For example, when the power domains on either side of the boundary 420 share a common clock, the buffer 410 may not need to be asynchronous.
[0055] The buffer 410 may receive a request (“Req”) signal from the input side when data is scheduled to be written to the buffer. After the data is written to the buffer, a request or valid data (“Val”) signal may alert the output side that new data is available from the buffer 410 . When the output side receives the valid data signal, it may read the new data from the buffer 410 and send a ready or acknowledgement (“Ack”) signal that is passed through the buffer 410 back to the input side. This system provides both sides of the buffer with knowledge of the activity of the other side. Further, these signals may be used to prevent the buffer from overflowing. Not shown in FIG. 4 is the reset signal for resetting the buffer 410 . Further, FIG. 4 does not show the data structure and data path for passing data and/or control signals across the boundary 420 .
[0056] The isolation module 360 may include two distinct stages of isolation. The first stage may comprise logical isolation to isolate the buffer 410 from circuitry on either side of the boundary 420 (e.g., a master node and a bus). The second stage may comprise electrical isolation to provide isolation at the power domain boundary 420 .
[0057] An isolation sequencer may trigger logical isolation by sending a “Logical Isolate In” signal 430 and a “Logical Isolate Out” signal 440 over the control signal bus 340 . When the “Logical Isolate In” signal 430 is asserted (e.g., pulled high due to the inverters at the inputs), a logical isolation gate 432 may block request signals from being input to the buffer 410 . Similarly, a logical isolation gate 434 may block acknowledgement signals from being sent to the input side. In effect, it would appear to circuitry on the input side that data was not being read from the buffer 410 .
[0058] On the output side, the “Logical Isolate Out” signal 440 may be used to logically isolate the buffer 410 from the circuitry it may interface with (e.g., a slave node or system bus). When the “Logical Isolate Out” signal 440 is asserted (e.g., pulled high), a logical isolation gate 442 may prevent valid data signals from reaching circuitry on the output side. Additionally, a logical isolation gate 444 may prevent acknowledgement signals from reaching the buffer 410 and, ultimately, a node on the input side of the power domain boundary 420 .
[0059] Accordingly, when the logical isolation gates 432 , 434 , 442 , and 444 are active, the buffer 410 may be logically isolated from circuitry on both the input side and the output side. Further, the input side and the output side of the buffer 410 may be logically isolated from one another.
[0060] The buffer 410 may provide electrical isolation at the power domain boundary 420 upon request (e.g., from the isolation sequencer). As such, the buffer 410 may selectively provide an electrical connection between the power domains on either side of the boundary 420 . For example, an “Electrical Isolate In” signal 450 from the control signal bus 340 may electrically disconnect or sever any connections (e.g., electrical connections) that lead into the input side from the output side. Similarly, an “Electrical Isolate Out” signal 460 from the control signal bus 340 may electrically disconnect or sever any connections that lead into the output side from the input side. When the electrical isolation signals 450 and 460 are asserted, the power domains on either side of the buffer 410 may power collapse independently from one another, where the electrical isolation may limit the effects of short circuit conditions at the boundary 420 (e.g., when a floating input to an active power domain is near the threshold voltage).
[0061] In accordance with some aspects of the disclosure, a sensor may be associated with the logical isolation gate 432 to generate an alert when the input side attempts to write to the buffer 410 during a time when the buffer 410 is isolated. This sensor may be used to detect uncommon events and programming mistakes without causing system failure, thereby contributing to a more robust design. For example, when the sensor issues an alert signal, a power controller may verify that the output side is powered on, and the isolation sequencer may de-isolate the buffer 410 . This sequence may be transparent to circuitry on the input side, or alternatively, the input side circuitry may be alerted when the output side circuitry is reconnected. The input side may then attempt to re-send a request message, and the transaction (e.g., sending of data across the boundary 420 ) may be completed as intended.
[0062] While FIG. 4 shows a buffer having a valid data signal and an acknowledgement signal, numerous other handshaking techniques may be implemented to coordinate the transfer of data across the boundary 420 . In other applications contemplated by the disclosure, more, fewer, or different handshaking signals may be implemented.
[0063] FIG. 5A shows a schematic diagram illustrating an exemplary cross-domain buffer 410 . More particularly, the diagram of FIG. 5A describes an asynchronous First-In-First-Out (FIFO) buffer, which is presented for explanatory purposes only, and other buffer types and topologies may be used without departing from the scope of the disclosure. In other implementations, synchronous FIFO buffers and/or other types of communication channels may be implemented between power domains and modified to provide the logical and electrical isolation described herein.
[0064] As shown in FIG. 5A , the buffer 410 may be disposed over both an input power domain 502 and an output power domain 504 . The buffer 410 may comprise a cross-domain memory device 530 which may receive input data 532 from a sending node (not shown) in the input power domain 502 , and the memory device 530 may further send output data 534 to a receiving node (not shown) in the output power domain 504 , thereby allowing data to cross the power domain boundary 420 . In some implementations in accordance with the disclosure, the memory device 530 may comprise a plurality of addressable memory cells in the input power domain 502 and a plurality of addressable memory cells in the output power domain 504 , the memory cells in the output power domain 504 being mirrored with the memory cells in the input power domain 502 .
[0065] The buffer 410 may write to the memory device 530 using a memory write enable signal 510 and a memory write address 512 in the input power domain 502 . The buffer 410 may also read from the memory device 530 using a memory read address 514 in the output power domain 504 .
[0066] The buffer 410 may have an input interface 506 that receives a request (“Req”) signal from the sending node in the input power domain 502 and provides an acknowledgement (“Ack”) signal from the receiving node back to the sending node. If both signals are asserted, the buffer 410 may determine that the sending node in the input power domain 502 is ready to write data and the receiving node in the output power domain 504 is ready to read data. The input interface 506 may then trigger a write to the memory device 530 through the memory write enable signal 510 .
[0067] The buffer 410 may further comprise address generators 508 and 509 to generate memory address values and/or encoded numerical values (e.g., Gray-coded counter values) for the power domains 502 and 504 , respectively. The address values may be used for reading and writing to the memory cells in the cross-domain memory device 530 . For example, the address generator 508 may determine a memory write address 512 to which a portion of the input data 532 may be written, and the address generator 508 may increment the memory write address 512 or a numerical value corresponding to the memory write address 512 after the portion of the input data 532 is written. Similarly, the address generator 509 may determine a memory read address 514 from which a portion of the output data 534 may be read, and the address generator 509 may increment the memory read address 514 or a numerical value corresponding to the memory read address 514 after the portion of the output data 534 is read.
[0068] Comparison modules 516 and 517 may calculate the difference between the addresses (or numerical values corresponding to the addresses) on either side of the boundary 420 to determine the instantaneous buffer depth and to provide this depth to logic in their respective power domains. Depth information may be useful in determining when the buffer 410 , through its memory device 530 , is full or empty. The maximum buffer depth may be associated with the number of bits used by the address generators 508 , 509 and the size of the memory device 530 . For example, five bits may be used to provide a maximum buffer depth of 2 5 or 32. In accordance with some aspects of the disclosure, the addresses may be encoded using Gray coding, and the address generators 508 , 509 may provide an extra bit to help differentiate between scenarios where the memory device 530 is full and scenarios where the memory device 530 is empty during depth comparison.
[0069] The address generator 508 may pass the write address, or a numerical value corresponding to the write address (e.g., a Gray-coded counter value), to the output power domain 504 via an electrical isolation gate 520 , where the electrical isolation gate 520 may selectively provide electrical isolation at the boundary. A similar electrical isolation gate 521 may enable the read address, or a numerical value corresponding to the read address (e.g., a Gray-coded counter value), to cross from the output power domain 504 to the input power domain 502 . While FIG. 5A shows electrical isolation gates 520 , 521 as implemented through AND gates, other logical gates (e.g., OR, NOR, and NAND) may be used. An exemplary transistor-level implementation of an electrical isolation gate is discussed further below, with respect to FIG. 5B .
[0070] The electrical isolation gate 520 may receive an “Electrical Isolate Out” signal 460 from a control signal bus to determine whether the output of the address generator 508 may pass through the electrical isolation gate 520 . When the signal 460 is asserted (e.g., pulled high), the electrical isolation gate 520 may block the write address or a corresponding numerical value from entering the output power domain 504 . When the signal 460 is de-asserted, the write address or the corresponding numerical value may be passed from the input power domain 502 to the output power domain 504 as an output signal that may be level shifted, depending on the relative voltages of the input power domain 502 and the output power domain 504 . Techniques for providing level shifting are readily known to one of ordinary skill in the art and will not be further described herein. The signal 460 may also determine whether or not the output data 534 may be read from the cross-domain memory device 530 .
[0071] Similarly, the electrical isolation gate 521 may selectively allow the read address or the corresponding numerical value generated in the output power domain 504 by the address generator 509 to enter the input power domain 502 . The electrical isolation gate 521 may receive an “Electrical Isolate In” signal 450 from the control signal bus to determine whether the electrical isolation gate 521 blocks the read address or corresponding numerical value from reaching the input power domain 502 . Both electrical isolation gates 520 , 521 may be the nearest gates to the power domain boundary 420 within their respective power domains 504 , 502 .
[0072] The buffer 410 may be capable of managing asynchronous clocks and/or clock jitter between the power domains 502 , 504 , such that the addresses and/or numerical values are reliably sent across the boundary 420 . Accordingly, the address and/or numerical value output from the electrical isolation gate 520 may be received by an output interface 507 . If the output interface 507 detects an incrementation in the write address (or the numerical value corresponding to the write address) that is output from the electrical isolation gate 520 , the output interface 507 may generate a valid data (“Val”) signal indicative of valid data in the memory device 530 , which may be sent to the receiving node (not shown) in the output power domain 504 . Once the receiving node is able to process the valid data signal, it may generate an acknowledgement (“Ack”) signal to be received by the output interface 507 and conveyed to the sending node (not shown) through the input interface 506 .
[0073] FIG. 5B shows a schematic diagram illustrating an exemplary electrical isolation gate. More specifically, FIG. 5B shows a transistor-level implementation of a NAND gate using complementary metal-oxide-semiconductor (CMOS) technology, which may be used to form the electrical isolation gates 520 and/or 521 in FIG. 5A .
[0074] The electrical isolation gate of FIG. 5B may comprise two p-channel MOS (PMOS) transistors 540 and 542 and two n-channel MOS (NMOS) transistors 544 and 546 . The PMOS transistors 540 and 542 may be connected in parallel between a net 570 and a supply voltage rail 550 . The NMOS transistors 544 and 546 may be connected in series between the net 570 and a ground rail 560 . As is known in the art, when either PMOS transistor 540 or 542 receives a low voltage at their gates, then the net 570 may be pulled to a high voltage. If both NMOS transistors 544 and 546 receive a high voltage at their gates, then the net 570 may be pulled to a low voltage. One range of voltages may be associated with a high logic value, and another range of voltages may be associated with a low logic value, where the ranges are chosen based, in part, upon the threshold voltages of the transistors 540 , 542 , 544 , 546 . For the purposes of the following discussion, a low logic value may be associated with voltages that enable PMOS transistors 540 , 542 (e.g., such that their sources and drains are connected) and disable NMOS transistors 544 , 546 (e.g., such that their sources and drains are not connected), whereas a high logic value may be associated with voltages that disable the PMOS transistors 540 , 542 and enable the NMOS transistors 544 , 546 .
[0075] The PMOS transistor 540 and the NMOS transistor 544 may both receive an input signal at their gates. Similarly, the PMOS transistor 542 and the NMOS transistor 546 may both receive a “pass” signal at their gates, where the pass signal may be the logical inverse of an electrical isolation signal. An output signal may be provided on the net 570 .
[0076] Through this implementation, the pass signal may determine whether or not the input signal is passed and inverted to become the output signal on the net 570 . As shown in FIG. 5A , the pass signal and the output signal may be received from or delivered to one power domain, whereas the input signal may be received from another power domain.
[0077] The electrical isolation gate of FIG. 5B may selectively and effectively block activity on one power domain from affecting activity in another power domain, thereby providing electrical isolation between the power domains. For example, when the pass signal is at a low logic value, the PMOS transistor 542 pulls the net 570 to a high voltage, forcing the output signal to have a high logic value. In such a condition, the output signal is independent of the input signal. This allows the input signal to vary its logic level and even reach the normally problematic intermediate voltages between logic levels without affecting the output signal on the net 570 .
[0078] The electrical isolation gate of FIG. 5B allows for one bit of information to pass a power domain boundary. Accordingly, it may be replicated as needed to pass addresses, numerical values, and/or other information across power domains.
[0079] FIG. 6 shows a block diagram of a system for providing isolation between power domains. As was also shown in FIG. 3 , a master node 112 may reside in a first power domain 102 (e.g., a master power domain 102 ), and a system bus 130 in a second power domain 107 (e.g., a slave, bus, or other power domain 107 ). The system bus 130 may be an interface (e.g., AXI interface) connecting the master node 112 to other nodes. However, the disclosed principles also apply to scenarios where two nodes are in communication with one another without using the system bus 130 (e.g., through the isolation module 360 h of FIG. 3 ).
[0080] A buffer 410 may be disposed at the boundary between the first power domain 102 and the second power domain 107 . The buffer 410 may, for example, be an asynchronous FIFO buffer as described above with respect to FIG. 5A . The buffer 410 may be selectively isolated from the master node 112 by logical isolation 620 , and the buffer 410 may also be selectively isolated from the system bus 130 by logical isolation 630 . The logical isolation 620 and 630 may be implemented as logical isolation gates as shown in FIG. 4 or other suitable circuitry for logically isolating the buffer 410 from the master node 112 and the system bus 130 . The isolation sequencer 354 may provide logical isolation signals 430 and 440 through the control signal bus 340 to the logical isolation 620 and 630 , respectively. The isolation sequencer 354 may also provide electrical isolation signals 450 and 460 through the control signal bus 340 to control the electrical isolation within the buffer 410 . The buffer 410 , together with the logical isolation 620 and 630 , may form an isolation module 360 a.
[0081] In accordance with the disclosed techniques, a power controller 152 may provide three reset signals 640 , 642 , and 644 relating to the first power domain 102 , the second power domain 107 , and the isolation module 360 a , respectively. The reset signals 640 and 642 may be provided after the respective power domains are powered on from a power collapsed state. In some contemplated implementations, the reset signal 644 may be a logical OR of the reset signals 640 and 642 , such that the reset signal 644 is triggered any time that either reset signal 640 or the reset signal 642 is triggered. As a result, the isolation module 360 a may be reset whenever either the master node 112 or the system bus 130 is reset.
[0082] In accordance with some aspects of the disclosure, the isolation module 360 a may be reset independently from the master node 112 and the system bus 130 , and vice versa. In other words, the power domains 102 , 107 and their constituent logic or processing nodes need not be reset when the buffer 410 is reset, thereby reducing the processing overhead associated with power collapse. For example, after an isolation sequence, the system bus 130 may be power collapsed. However, the master node 112 may retain an active channel configuration for communication with the system bus 130 even when the system bus's power domain 107 is collapsed. At a later time, the power domain 107 may be powered on and isolation may be removed, with the system bus 130 and the buffer 410 being reset in the process. The master node 112 , having not undergone a reset during the power collapse of the system bus 130 , may use the active channel configuration to readily resume communication with the system bus 130 over the buffer 410 .
[0083] The power controller 152 may send stop clock signals 650 and 652 to the master node 112 and the system bus 130 , respectively. The signals 650 and 652 may be asserted when the power domains are being isolated or de-isolated from one another. For example, during an isolation sequence, the stop clock signals 650 and 652 may both be asserted before the domains are logically and electrically isolated from one another. After the logical isolation and electrical isolation are applied, the stop clock signals 650 and 652 may individually be de-asserted, depending on whether each power domain intends to continue operation after the isolation process. The stop clock signals 650 and 652 may also be used during a de-isolation process, as will be described in further detail with respect to FIG. 8 .
[0084] The topology shown in FIG. 6 provides the benefit of logically separating the domain transition logic (e.g., the buffer 410 ) from circuitry in the adjacent power domains (e.g., the master node 112 and the system bus 130 ). The increased level of modularity simplifies independent power collapse of the power domains 102 and 107 .
[0085] FIG. 7 shows a flowchart illustrating a sequence 700 for providing isolation at a selected boundary between two power domains.
[0086] At action 710 , an isolation sequencer may assert a busy state indicating that the isolation sequencer is in the process of performing an isolation sequence. In accordance with some aspects of the disclosure, the isolation sequencer may service one or more modules (e.g., the power controller 152 of FIG. 3 ), where each module may place isolation requests to the isolation sequencer. If the isolation sequencer is limited to performing one isolation sequence at a time, the busy signal may be used to indicate the isolation sequencer's availability to the requesting module(s) placing isolation requests. The isolation sequencer may store a queue of isolation requests, or the requesting module(s) may wait to repeat the isolation requests at another time if the isolation sequencer is busy.
[0087] In accordance with some aspects of the disclosure, the isolation sequencer may be capable of implementing a plurality of isolation sequences in parallel. Accordingly, the isolation sequencer may assert the busy signal when it is at maximum capacity. If the isolation sequencer is capable of servicing all potential requests of the module(s) simultaneously, a busy signal may not be used.
[0088] At action 720 , the isolation sequencer may stop the clocks on both sides of the selected boundary. These clocks may, for example, be a core clock of a master node and a bus clock of an interface. Alternatively, if a master node is connected directly to a slave node or a second master node, the two clocks may be the core clock of the master node and a secondary clock of the slave node or of the second master node. In some implementations, a few processing cycles may be permitted for the nodes within the affected power domains to store any intermediate work before the clocks are stopped.
[0089] In accordance with some aspects of the disclosure, the isolation sequencer may issue a halt signal to the power domains to indicate that their clocks will be stopped. The isolation sequencer may wait for acknowledgement from the power domains that the power domains (and the nodes therein) are ready to have their clocks stopped before performing the action 720 . The isolation sequencer may also wait for an acknowledgement that buffers within isolation modules associated with the boundary between the two power domains are empty, as the data within these buffer may be lost once the isolation modules are activated.
[0090] At action 730 , the isolation sequencer may enable logical isolation around a buffer located at the boundary. This action may be performed in accordance with the accompanying description of FIGS. 4 and 6 above. When the action 730 is completed, each power domain may be logically isolated from the buffer.
[0091] At action 740 , the isolation sequencer may enable electrical isolation at the boundary, which may, for example, occur within the buffer. This action may be performed in accordance with the accompanying descriptions of FIGS. 4 and 5 above. Further, the isolation sequencer may store information indicating that the selected boundary has been isolated.
[0092] When the action 740 is completed, the two power domains on either side of the boundary may be isolated from one another. Accordingly, either or both of the power domains may be power collapsed at action 750 without affecting the other power domain. If a selected power domain shares a boundary (e.g., exchanges data and/or control signals) with more than one other power domain, the isolation sequencer may need to perform the sequence 700 at other power domains before allowing the selected power domain to collapse (e.g., by notifying a power controller that the selected power domain is isolated, as described in FIG. 3 ). If a plurality of buffers are implemented at a boundary, the process 700 may be performed in parallel on each of the plurality of buffers at the boundary.
[0093] Also at the action 750 , if a power domain is intended to remain powered on after being isolated, its clock may be restarted. In accordance with the disclosed techniques, the power domains themselves need not necessarily be restarted (e.g., through a full boot-up sequence and reestablishment of communication channels shared with other power domains). A few processing cycles may be required to recover any intermediate work and resume operation, but significant time may be saved when compared to a full reset of the power domain.
[0094] The nodes within the recently isolated power domains may continue with the operations being performed prior to the clocks being stopped. In some scenarios, a node in an active (powered on) power domain may not even be aware that it has been isolated from a node in another power domain across the selected boundary. As a result, the node may maintain seemingly active communication channels. If the node later tries to send a message on one such channel before the node intended to receive the message is powered on, the system may provide an alert and/or begin a power sequence and a de-isolation sequence to reestablish the communication channel.
[0095] In some scenarios, neither of the power domains associated with the selected boundary are power collapsed after the selected boundary is isolated. As such, the decision to apply isolation at a boundary may be made independently from a power collapse decision. One of the power domains may be power collapsed at a later time, if each of the other boundaries is isolated.
[0096] FIG. 8 shows a flowchart illustrating a sequence 800 for removing isolation at a selected boundary between two power domains. The sequence 800 may generally be applied during a time when both power domains are powered on and nodes within these power domains are ready to resume communications between each other.
[0097] At action 810 , an isolation sequencer may assert a busy state indicating that the isolation sequencer is in the process of performing an isolation sequence. As described above with respect to the isolation sequence, the busy state may not be required, depending on the capabilities of the isolation sequencer.
[0098] At action 820 , the isolation sequencer may stop the clocks, if active, of the power domains on either side of the selected boundary.
[0099] At action 830 , the isolation sequencer may disable the electrical isolation within the buffer located at the selected boundary. This action may be performed in accordance with the accompanying descriptions of FIGS. 4 and 5 above.
[0100] At action 840 , the isolation sequencer may issue a restart signal to the buffer. This action may set the buffer depth value to zero and set the read pointer to be equal to the write pointer (e.g., via manipulation of the values stored and generated by the address generators of FIG. 5A ).
[0101] At action 850 , the isolation sequencer may disable the logical isolation around the buffer, thereby connecting the buffer to nodes and/or interfaces in the power domains on either side of the selected boundary. This action may be performed in accordance with the accompanying description of FIGS. 4 and 6 above. In accordance with some aspects of the disclosure, the isolation sequencer may update stored information to indicate that the selected boundary is no longer isolated.
[0102] At action 860 , the clocks of the power domains on either side of the selected boundary may be restarted. However, these power domains do not necessarily need to be further reset, thereby saving processing cycles with respect to prior implementations. From the perspective of each power domain, it may seem as though the other domain was never disconnected, but instead was simply left idle. This can greatly reduce the effort associated with re-configuring each data connection.
[0103] The isolation and de-isolation sequences of FIGS. 7-8 may be initiated by signals sent from a power controller in the always-on power domain, the isolation sequencer itself, or even from processing nodes or logic within the collapsible power domains.
[0104] FIG. 9 shows a block diagram of an exemplary wireless device 900 having a plurality of power domains that may be selectively isolated from one another in accordance with the disclosed principles. The wireless device 900 may comprise a system-on-chip device 922 (or system-in-package device 922 ) having a processor 964 , a display controller 926 , a wireless controller 940 , a decoder 930 , an encoder 932 , a first memory device 910 , a second memory device 912 , an isolation sequencer 354 , and a power controller 152 . As shown in FIG. 9 , the system-on-chip device 922 may couple with a display 928 , a speaker 936 , a microphone 938 , a wireless antenna 942 , and a power supply 944 that may each be external to the system-on-chip device 922 .
[0105] The system-on-chip device 922 may be partitioned into multiple power domains 109 , 913 , 927 , 933 , 941 , and 965 . Each power domain may include logic or processing nodes that are selectively coupled to the power supply 944 via one or more power connections (not shown). Each power domain may be designated as always-on or collapsible. An always-on power domain (e.g., the power domain 109 ) may be powered on at all times that the wireless device 900 is powered on. A collapsible power domain (e.g., the power domains 913 , 927 , 933 , 941 , and 965 ) may be powered off during times when the logic or processing nodes in the power domain are not utilized. Each collapsible power domain may be powered on or off independently of the other collapsible power domains. As used herein, “power off,” and “power collapse” are synonymous terms that are used interchangeably.
[0106] Power consumption due to leakage current can be reduced by powering off as many collapsible power domains within the system-on-chip device 922 as possible when these power domains are not in use. Many processing nodes may only be active for a small percentage of the time while the wireless device 900 is idle. In this case, many of the collapsible power domains can be powered off (e.g., “collapsed”) for a large portion of the time to reduce power consumption and extend standby time.
[0107] The processor 964 may be disposed in the power domain 965 of the system-on-chip device 922 and may comprise a microcontroller, a digital signal processor (DSP), or another type of processor. The processor 964 may be coupled with the memory devices 910 , 912 , which may both be provided in the power domain 913 . The memory devices 910 , 912 may share an interface by which they communicate with the processor 964 (as shown in FIG. 9 ) or they may have separate interfaces to the processor 964 . An isolation module 360 may be placed at each of the one or more interfaces between the memory devices 910 , 912 and the processor 964 to selectively provide isolation between the power domain 965 and the power domain 913 .
[0108] The memory devices 910 , 912 may comprise volatile or nonvolatile memory. For example, volatile memory may store data and code used by the processor 964 and may be implemented with, for example, synchronous dynamic RAM (SDRAM) or other types of memory. Non-volatile memory may provide bulk storage and may be implemented with, for example, NAND Flash, NOR Flash, or other types of memory.
[0109] The processor 964 may be coupled to the display controller 926 through an isolation module 360 , where the display controller 926 may format and/or provide video data for the display 928 . The display controller 926 may be disposed in the power domain 927 , which may be power collapsed when the system-on-chip device 922 is not providing video data to the display 928 . The video data may, for example, be transferred from the memory device 910 to the display controller 926 through the processor 964 .
[0110] The processor 964 may further be coupled with the wireless controller 940 , which may include a modem and may reside in the power domain 941 . The wireless controller 940 may control the wireless antenna 942 to send and receive wireless data, which may passed to the processor 964 through an isolation module 360 .
[0111] The processor 964 may further be coupled with the decoder 930 and the encoder 932 , which may provide and receive audio data (e.g., voice data) to and from the speaker 936 and the microphone 938 , respectively. The decoder 930 and the encoder 932 may be disposed in the power domain 933 that may be power collapsed when the speaker and microphone are disabled. The decoder 930 and the encoder 932 may be integrated into a unified coder-decoder (CODEC) or may otherwise share a power domain 933 . Isolation modules 360 may be deployed between the power domain 933 of these peripherals and the power domain 965 of the processor 964 . As shown in FIG. 9 , the decoder 930 may have a separate interface to the processor 964 than does the encoder 932 , and so a plurality of isolation modules 360 may be used.
[0112] As described above, the power controller 152 may generate various control signals to support power collapsing and powering on the collapsible power domains. The power controller 152 may maintain a finite state machine (FSM) for each processing node within the system-on-chip device 922 (e.g., the display controller 926 ) and/or for each collapsible power domain. Using various inputs (e.g., hardware or software interrupts) and state information indicated by the finite state machines, the power controller 152 may generate control signals to power collapse and power on the collapsible power domains at appropriate times to optimize energy consumption. As described above, the power controller's control signals may also include signals to stop the clocks of the power domains and to reset the power domains and the buffers within the isolation modules 360 .
[0113] The isolation sequencer 354 may perform any of the functions described above (e.g., with respect to FIGS. 4-8 ). For example, the isolation sequencer 354 may generate and send control signals on the control signal bus 340 to isolate various power domains from one another through the isolation modules 360 . The isolation sequencer 354 may make decisions that are not necessarily dependent on the decisions and actions of the power controller 152 . For example, the isolation sequencer 354 may isolate a power domain from another power domain on the basis of whether communication is expected between the power domains instead of simply because one or both of the power domains are scheduled to be power collapsed by the power controller 152 . In other words, the isolation decisions may be decoupled, at least partially, from the power collapse decisions. The standardization and decoupling of isolation control sequences from power collapse control sequences can provide the benefits of increased design simplicity and reuse as well as increased flexibility in power control.
[0114] In general, the system-on-chip device 922 may include fewer, more, and/or different processing nodes than those shown in FIG. 9 . The specific processing nodes included in the system-on-chip device 922 are typically dependent on the requirements of the device 922 , such as the communication systems and external units intended to be supported. The system-on-chip device 922 may also couple to fewer, more, and/or different external units than those shown in the exemplary wireless device 900 of FIG. 9 .
[0115] The processor 964 may be implemented in a single CMOS integrated circuit for various benefits such as smaller size, lower cost, less power consumption, and so on. Further, any or all of the external units shown in FIG. 9 may be included in a common integrated circuit with the processor 964 .
[0116] The depiction of the wireless device 900 in FIG. 9 does not take the size or layout of the various units into account. In many implementation, the always-on power domain 109 may occupy only a small portion (e.g., two to three percent) of the total die area of an integrated circuit and may be the basis for a similarly small portion of power consumption when the wireless device 900 is in an active state. Thus, leakage current for the wireless device 900 may be significantly reduced by powering off the collapsible power domains when the processing nodes within these domains are not needed.
[0117] Although FIG. 9 depicts a wireless device 900 , the isolation modules 360 and other elements within the system-on-chip device 922 may also be integrated into numerous other devices such as set-top boxes, music players, video players, entertainment units, navigation devices, personal digital assistants (PDA), fixed location data units, cellular phones, and computers. In general, the disclosed techniques are applicable to a wide range of systems. For example, wired computing systems, transportation systems, medical devices, imaging and video-related systems, and systems for managing sensors are only some of the other systems that benefit from the disclosed techniques for efficiently applying signal isolation and buffers between collapsible power domains.
[0118] While various embodiments in accordance with the disclosed principles have been described above, it should be understood that they have been presented by way of example only, and are not limiting. Thus, the breadth and scope of the disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages.
[0119] It is contemplated that buffers, logic gates, nodes, buses, and other elements be provided according to the processes and structures disclosed herein in integrated circuits of any type to which their use commends them, such as ROMs, RAM (random access memory) such as DRAM (dynamic RAM), and video RAM (VRAM), PROMs (programmable ROM), EPROM (erasable PROM), EEPROM (electrically erasable PROM), EAROM (electrically alterable ROM), caches, and other memories, and to microprocessors and microcomputers in all circuits including ALUs (arithmetic logic units), control decoders, stacks, registers, input/output (I/O) circuits, counters, to general purpose microcomputers, RISC (reduced instruction set computing), CISC (complex instruction set computing) and VLIW (very long instruction word) processors, and to analog integrated circuits such as digital to analog converters (DACs) and analog to digital converters (ADCs). ASICS, PLAs, PALs, gate arrays and specialized processors such as digital signal processors (DSP), graphics system processors (GSP), synchronous vector processors (SVP), image system processors (ISP), as well as testability and emulation circuitry for them, all represent sites of application of the principles and structures disclosed herein. Still other larger scale applications include photocopiers, printers, modems and other telecommunications equipment, calculators, radio and television circuitry, microwave oven controls, automotive microcontrollers, and industrial controls.
[0120] Implementation is contemplated in discrete components or fully integrated circuits in silicon, gallium arsenide, or other electronic materials families, as well as in other technology-based forms and embodiments. It should be understood that various embodiments of the invention can employ or be embodied in hardware, software, microcoded firmware, or any combination thereof. When an embodiment is embodied, at least in part, in software, the software may be stored in a non-transitory machine-readable medium.
[0121] Various terms used in the present disclosure have special meanings within the present technical field. Whether a particular term should be construed as such a “term of art” depends on the context in which that term is used. “Connected to,” “in communication with,” “associated with,” or other similar terms should generally be construed broadly to include situations both where communications and connections are direct between referenced elements or through one or more intermediaries between the referenced elements. These and other terms are to be construed in light of the context in which they are used in the present disclosure and as one of ordinary skill in the art would understand those terms in the disclosed context. The above definitions are not exclusive of other meanings that might be imparted to those terms based on the disclosed context.
[0122] Words of comparison, measurement, and timing such as “at the time,” “immediately,” “equivalent,” “during,” “complete,” “identical,” and the like should be understood to mean “substantially at the time,” “substantially immediately,” “substantially equivalent,” “substantially during,” “substantially complete,” “substantially identical,” etc., where “substantially” means that such comparisons, measurements, and timings are practicable to accomplish the implicitly or expressly stated desired result.
[0123] Additionally, the section headings herein are provided for consistency with the suggestions under 37 C.F.R. 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the subject matter set forth in any claims that may issue from this disclosure. Specifically and by way of example, although the headings refer to a “Field of the Disclosure,” such claims should not be limited by the language chosen under this heading to describe the so-called technical field. Further, a description of a technology in the “Background” is not to be construed as an admission that technology is prior art to any subject matter in this disclosure. Neither is the “Summary” to be considered as a characterization of the subject matter set forth in issued claims. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings set forth herein.
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The feature size of semiconductor devices continues to decrease in each new generation. Smaller channel lengths lead to increased leakage currents. To reduce leakage current, some power domains within a device may be powered off (e.g., power collapsed) during periods of inactivity. However, when power is returned to the collapsed domains, circuitry in other power domains may experience significant processing overhead associated with reconfiguring communication channels to the newly powered domains. Provided in the present disclosure are exemplary techniques for isolating power domains to promote flexible power collapse while better managing the processing overhead associated with reestablishing data connections.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/972,192 of Lowry et al., entitled “Transcorporeal spinal decompression and repair system and related method”, as filed on Sep. 13, 2007.
FIELD OF INVENTION
[0002] The invention relates to devices and methods of spinal surgery. More particularly, the invention provides an implant for use in spinal repair surgery and a method for preparing the vertebral volume to receive the implant.
INCORPORATION BY REFERENCE
[0003] All publications, patents and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference.
[0004] In particular, U.S. patent application Ser. No. 11/855,124 of Lowry et al. (filed on Sep. 13, 2007, entitled “Implantable bone plate system and related method for spinal repair”), U.S. Provisional Patent Application 60/972,199 of Lowry et al. (filed on Sep. 13, 2007, entitled “Device and method for tissue retraction in spinal surgery”) as well as the U.S. patent application (Atty. Docket 10323.702.200) of the same inventors and title, being filed concurrently with the present application, U.S. Provisional Patent Application No. 60/976,331 of Lowry et al. (filed on Sep. 28, 2007, entitled “Vertebrally mounted tissue retractor and method for use in spinal surgery”), and U.S. Provisional Patent Application No. 60/990,587 of Lowry et al. (filed on Nov. 27, 2007, entitled “Methods and systems for repairing an intervertebral disk using a transcorporal approach”) are all incorporated by this reference.
BACKGROUND OF THE INVENTION
[0005] The performance of cervical discectomy, excision of tissue, and neural element decompression procedures have become standard neurosurgical approaches for the treatment of disorders of the spine and nervous system, as may be caused, for example, by disc degeneration, osteophytes, or tumors. The compressive pathologies impinge onto a neural element, causing a compression of nerve tissue that results in a symptomatic response such as loss of sensation or strength, occurrence of pain, or other related disorders. The majority of these procedures are performed with an anterior approach to the cervical spine. Disc and bone tissue are removed, a neural decompression is achieved, and a spinal repair procedure is performed.
[0006] The current conventional repair procedure includes a vertebral fusion in which a biocompatible implant is inserted and secured between the affected adjacent vertebrae. A bone plate is then is rigidly attached to the two vertebrae adjacent to the implant, immobilizing these vertebral segments and preventing the expulsion of the implant from the intervertebral space. Subsequently, osteogenesis of the vertebrae into the implant occurs, and ultimately the adjacent vertebrae fuse into a single bone mass. The fusion of the vertebral segments, however, can lead to problematic results. For example, the immobility of the fused vertebral joint is commonly associated with the progressive degeneration of the adjacent segments, which, in turn, can lead to degeneration of the intervertebral discs on either side of the fused joint.
[0007] Implantation of an artificial disc device offers an alternate approach to vertebral fusion. The objective of the artificial disc device is to preserve the relative motion of the vertebrae across the joint and to restore normal articulating function to the spinal column. In spite of the benefits that these procedures have brought to patients, both fusion and disc replacement have inherent problems. The surgeries are extensive, recovery time is relatively long, and there is often a loss of function, particularly with the use of fusion implants. The long-term biocompatibility, mechanical stability, and durability of replacement disc devices have not been well established. Further, there is no clinical consensus that the use of a replacement disc reduces the risk of adjacent segment degeneration.
[0008] Methods for surgery on the spine and cervical discs from an anterior approach were first developed in the 1950's, and a number of variations have been developed since then. Each anterior cervical discectomy procedure, however, has had to face the challenge represented by removing the tissue overlaying the compressing lesion (i.e., the herniated disc material, osteophyte or tumor) after having dissected through the soft tissue anterior to the spine. Early procedures exposed the compressing tissue by first making a cylindrical bone-and-disc defect in the spine centered on the disc space in sagittal and coronal planes, and generally following the plane of the disc itself. Later procedures made use of a rectangular, box-like defect in the disc space centered on the disc space and generally following the plane of the disc.
[0009] Procedures recently developed by Jho (referenced below) were motivated by the concern that procedures like those described above destroyed more of the natural disc tissue than was necessary to remove a laterally-positioned disc herniation or osteophyte (a bone spur). An alternative procedure, an uncovertebrectomy, was therefore developed that involved the removal of only the lateral-most aspect of the disc space, and the vertebral bone above and below it, which together comprise the entire uncovertebral joint. (See Choi et al., “Modified transcorporeal anterior cervical microforaminotomy for cervical radiculopathy: a technical note and early results”, Eur. Spine J. 2007 Jan. 3; Hong et al., “Comparison between transuncal approach and upper vertebral transcorporeal approach for unilateral cervical radiculopathy—a preliminary report”, Minim Invasive Spine Surgery, 2006 October; 49 (5):296-301; and Jho et al., “Anterior microforaminotomy for treatment of cervical radiculopathy: part 1: disc-preserving functional cervical disc surgery”, Neurosurgery 2002 November; 51 (5 Suppl.): S46-53.) This new type of procedure allows much of the disc space to remain untouched. While preserving more of the disc space and disc material than its predecessor procedures, the uncovertebrectomy nevertheless does obliterate the uncovertebral joint, and there is concern in the field regarding the eventual development of spinal instability at that disc level. Further, drilling bone at high speed adjacent to the nearby vertebral artery and sympathetic nerve process increases the concern of a higher risk of vertebral artery, secondary soft tissue injury, and Horner's Syndrome.
[0010] In another refinement of the uncovertebrectomy procedure, an anterior cervical microforamenotomy, the uncinate process and the lateral disc tissue may be left largely intact as a hole is drilled through the bone adjacent to the disc space near the uncinate process. In both uncovertebrectomy and anterior microforamenotomy, the exposure and decompression of the neural elements generally follow the plane of the disc space. While vertebral artery injury and spinal instability remain concerns with both procedures, the risk associated with anterior microforamenotomy is considered less than that of uncovertebrectomy.
[0011] An additional refinement of both uncovertebrectomy and anterior microforamenotomy is a transcorporeal decompression procedure (also referred to as an upper vertebral transcorporeal foramenotomy or a transcorporeal discectomy) may have advantages. This procedure differs from its disc space-preserving precedent procedures in several ways. First, the axis of the access hole drilled to expose the compressing pathology (e.g., herniated disc fragment) does not parallel the plane of the disc, but instead entirely avoids the disc space plane anteriorly and captures the disc only at its most posterior aspect. Second, while uncovertebrectomy and anterior cervical microforamenotomy are applicable only to lateral pathology, the transcorporeal decompression is potentially applicable to compressing pathology located laterally in the disc space region, bilaterally, or in the midline. Further, the procedure is performed from a substantially medial position on the vertebra assuring maximal distance from the vertebral artery and other sensitive soft tissue and thereby minimizing the risk of accidental injury.
[0012] Multiple technical challenges remain, however, in optimizing the transcorporeal cervical decompression procedure for general surgical use. First, manually orienting and controlling a hand-held cutting tool to make an access channel is a subjective and error-prone procedure. The target pathology is wholly behind and/or within the bony structure of the vertebra and is not visible in any way when approached from a traditional anterior approach to the cervical spine. As the channel is essentially being driven blindly, it can easily fail to capture the targeted pathology being within the range of the posterior opening of the access channel. Consequently the surgeon needs to prolong the procedure, and explore the space by excising tissue until the pathology is found. The exploration typically leads to the access channel becoming larger than necessary and undesirably irregular, thus putting surrounding bone at risk of fracturing during or after the procedure. Given the proximity of many target pathologies to the uncovertebral joint and the vertebral artery, it is likely that exploration of the space will lead to removal of the stabilizing bone and disc tissue. This tissue damage or loss can cause spinal instability, and may further result in accidental perforation of the vertebral artery.
[0013] Second, a manual drilling process increases the risk of over penetration into the spinal canal, with highly undesirable consequences.
[0014] Third, the posterior longitudinal ligament, once exposed in the access channel, can be difficult to open. The objective is to remove the ligament cleanly from the access channel area so as to provide unobstructed visualization of the compressed neural tissue. Current surgical techniques are subjective and time-consuming, often producing a shredding of the ligament within the access channel rather than its removal therefrom, thereby impeding the visualization of the underlying target pathology or dura mater protective layer.
[0015] Fourth, currently available microsurgical instruments are not well-suited for retrieving the herniated disc or bone fragments that may be found deep to the posterior longitudinal ligament.
[0016] Fifth, after the decompression is complete, the present solutions for filling the void remaining in the vertebra are not completely satisfactory. Demineralized bone matrix putties or similar materials can fill the defect but they offer no resistance to the normal compressing or torsional forces until calcification occurs. Such materials may also impose a new source of compression on the exposed neural structures if too much putty is applied or if the vertebra deforms or sustains a compression fracture subsequently because of the absence of an implant that sufficiently resists compressive forces.
[0017] Sixth, after a solid implant plug is placed in the surgically-formed access channel, there is presently no anterior cervical plate suited to preventing its outward migration. Currently available anterior cervical plates are designed to be placed across two or more adjacent vertebrae at or near the midline, not laterally, as would be needed for lateral compressing lesions. Existing plates also are designed as motion-restriction or motion-prevention devices to be placed bridging across a disc space rather than onto a single vertebral body, consequently they are too large and are counterproductive in the application such as that described above where the objective is to preserve the articulation and relative motion of the adjacent vertebrae.
[0018] Accordingly, there is a need for a system and method whereby any compressing spinal pathology may be removed or moved so as to decompress the neural elements involved while desirably also (1) preserving native disc and bone tissue and the natural motion of the spine with natural disc material, (2) minimizing the risk of injury to the vertebral artery, (3) minimizing the risk of structural spinal instability, (4) minimizing the risk of an inadequate decompression, (5) minimizing the risk of injury to the protective dura mater layer, (6) minimizing the risk of post operative bleeding and/or (7) minimizing the risk of a subsequent vertebral body fracture due to an unrepaired defect within it.
SUMMARY OF THE INVENTION
[0019] The invention provides a system and method for forming and repairing an access channel through a vertebral body, typically a cervical vertebral body, for the purpose of gaining access to a site in need of a medical intervention. In its formation, the channel originates on the anterior surface of the vertebral body, and it then provides access from the anterior approach. The channel follows a prescribed trajectory to a prescribed exit on the posterior surface of the vertebral body, and provides an opening at the site of sufficient size to address the medical need. The access channel is typically formed in cervical vertebral bodies. The nature of the medical need typically includes the need for a decompression procedure, as may occur as a result of a problematic portion or the whole of a herniated disc, an osteophyte, a thickened ligament, a tumor, a hematoma, a degenerative cyst, or any other compressing pathology. The medical intervention may be as minimal as observing the site, or performing exploration, or it may include a diagnostic procedure, or delivering a therapy, or it may include a surgery. A typical surgery performed through the access channel can include decompressing a neural element, such an individual nerve root, a spinal cord, or a cauda equina.
[0020] The system of the invention further includes an implantable bone repair device having an external geometry complementary to the internal geometry of the access channel, and a method for repairing or healing the channel by implanting such device. Some embodiments of the device include materials that are biocompatible, biologically absorbable, or any material known to be able to substitute for bone, and to be able to be stably and effectively integrated into bone. The device may further include as well as biologically active agents, such as osteogenic agents, that promote healing of the wound represented by the access channel, and fusion of the device such that it integrates into the vertebral body.
[0021] In some embodiments, the implantable bone repair device includes an assembly with a porous body that includes actual bone tissue. Such bone tissue may be provided by the bone removed during the formation of the channel itself, or it may come from another site from the patient as an autologous graft, or it may be provided by a separate donor.
[0022] The system to form and repair an access channel includes a bone cutting tool with a cutting element, a bone plate configured to be secured to the anterior surface of the vertebral body and having an opening sized to receive the cutting element; and a trajectory control sleeve configured to detachably engage the bone plate and having a cylinder configured to receive the cutting element. The bone plate and the trajectory control sleeve, when mutually engaged, are configured to cooperate to guide the cutting element to form the access channel with a prescribed trajectory from the anterior entry to the prescribed posterior opening.
[0023] Embodiments of a method for prescribing of the point of anterior entry and the channel trajectory toward the posterior opening are typically provided by a physician who observes the cervical spine of the patient radiographically. From such observation of patient anatomy and the site of pathological interest, the physician prescribes a trajectory according to a cranio-caudal axis and a medial lateral axis with respect to a point of entry on the anterior surface of vertebral body. Such radiographic observation may occur before the attachment of the bone plate, to be summarized below, and/or after the attachment of the bone plate.
[0024] Returning to summarizing the system for forming the access channel, some embodiments include fixation elements to secure the bone to the anterior surface of the vertebral body. The bone plate may include openings to accommodate fixation elements to secure the bone plate to the anterior surface of the vertebral body. In some embodiments, the bone plate and fixation elements are configured of a biocompatible material. In some embodiments, the bone plate and the fixation elements have a composition and structure of sufficient strength that that the bone plate may be permanently implanted.
[0025] Embodiments of the trajectory control sleeve may be configured to direct the bone cutting tool on a trajectory prescribed by the method above, the prescribed trajectory being an angle according to a cranio-caudal axis and a medial lateral axis with respect to a reference plane tangential to the access channel entry on the anterior surface of vertebral body.
[0026] Embodiments of the bone plate provide a reference plane such that the trajectory control sleeve, when secured to the bone plate, may be configured with a range of angles formed on two axes with respect to the plane of the bone plate, a cranio-caudal axis and a medial lateral axis, the range of the angles varying between about 1 degree and about 30 degrees from an angle perpendicular to the plate. In typical embodiments, the range of the angles varies between about 10 degrees and about 30 degrees from the perpendicular angle. In some embodiments, the system includes a plurality of trajectory control sleeves, the sleeves varying in regard to angles formed with respect to a plane represented by the bone plate when secured thereto, the angles ranging between about 10 degrees and about 30 degrees cranio-caudally from a perpendicular angle.
[0027] In some embodiments, the trajectory control sleeve and the bone plate have mutually-engageable features that orient the engagement of the trajectory control sleeve on the bone plate in a configuration that allows the trajectory control sleeve to guide the cutting tool into the vertebral body with the prescribed trajectory. And in some embodiments, the trajectory control sleeve includes a contact surface for engaging a corresponding surface on the bone cutting tool, the surfaces configured so as to limit the penetration of the cutting tool into the vertebral body to a prescribed depth.
[0028] In some embodiments, the posterior surface of the bone plate includes one or more penetrating elements configured to impinge into the vertebral bone tissue to improve fixation and resist the torsional forces associated with bone cutting procedures. In some embodiments, the bone plate includes an anatomically-orienting feature to establish the position of the bone plate relative to the medial centerline of the vertebral body. In some embodiments, the bone plate includes a biocompatible material. And in some embodiments, at least a posterior surface of the bone plate is of sufficiently porous composition to support in-growth of bone.
[0029] In various embodiments, the bone-cutting tool is any of a drill, a reamer, a burr, or cylindrical cutting tool, such as a core cutter or a trephine. In some of these embodiments, the cutting element of the bone-cutting tool has a cutting diameter of between about 5 mm and about 7 mm.
[0030] As noted above, embodiments of the implantable bone repair device have an external geometry complementary to the internal geometry of the access channel. These bone repair device embodiments may be sized to be insertable through an opening of the bone plate, the opening also being sized to receive the bone cutting element. In some embodiments, the bone repair device includes an abutting surface configured to engage a corresponding surface of the bone plate through which it is implanted, the engagement of these surfaces adapted to prevent the bone repair device from penetrating too deeply into or through the access channel of the vertebral body. In some embodiments, the bone repair device includes receiving features in or on its anterior surface configured to accommodate the attachment of an insertion tool.
[0031] In some of these embodiments, bone repair device and the bone plate have mutually engageable orientation and locking features. In various embodiments, the locking engagement results from the application of an axial force to snap the locking feature into a corresponding retaining feature of the bone plate. In other embodiments, the locking engagement results from the application of a torsional force to engage the locking feature into a corresponding retaining feature in or on the bone plate.
[0032] In some embodiments of the surgical system the bone repair device comprises a porous cage with a porosity sufficient to permit through movement of biological fluids, such as blood, and bone cells. The composition of the porous cage portion of the device may include any of a polymer, a metal, a metallic alloy, or a ceramic. An exemplary polymer may polyetheretherketone (PEEK), which may be present in the form of PEEK-reinforced carbon fiber, or hydroxyapatite-reinforced PEEK. In some embodiments of the bone repair device with a porous cage, the porous cage device includes a closeable opening through which harvested bone material (such a native bone from the access channel site) may be passed. And in some of these embodiments, the porous cage device includes a closeable cap configured to increase pressure on the harvested bone within the cage as the cap is closed. Further, some embodiments include an internal element adapted to enhance compressive force applied to the contents of the porous cage upon application of compressive force to the cage, such force inducing extrusion of harvested bone and blood from within the cage through its porous structure to the external surfaces of the cage.
[0033] Some embodiments of the surgical system include a trajectory and depth visualization device. In some of these embodiments, the trajectory and depth visualization device includes a radio-reflective feature so as to confirm the location of the bone plate device on the appropriate vertebral body and to facilitate the extrapolation of the projected trajectory of the bone cutting tool using a radiographic image. In some embodiments, the trajectory and depth visualization device includes visual markings to indicate the distance from the point of contact with the vertebral body and cutter penetration control feature on the bone cutter guide device.
[0034] A method for performing a procedure through a vertebral body overlaying a site in need of a medical procedure includes attaching the bone plate on the anterior surface of the vertebral body, engaging the trajectory control sleeve to the bone plate, inserting a bone cutting tool through the trajectory control sleeve, and forming an access channel body by removing bone with the bone cutting tool (the channel having a centerline co-incident with the centerline of the trajectory control sleeve through the vertebral), disengaging the trajectory control sleeve from the bone plate, and performing the medical procedure through the open space provided by the access channel and the opening on the posterior surface of the vertebral body.
[0035] The access channel follows a prescribed trajectory from an anterior entry point to a prescribed opening on a posterior surface of the vertebral body in the locale of the site in need of the medical procedure. The prescription for the points of entry and exit and the vectors of the access channel are determined by radiographic observations and measurements, as summarized above. In some embodiments of the method, forming the access channel includes forming the channel with a constant, circular cross-section along a single, straight axis aligned with the trajectory control sleeve.
[0036] Before engaging the trajectory control sleeve to the bone plate, the method may include selecting the sleeve to be used in the procedure such that when the sleeve and the bone plate are engaged, the sleeve has an angular orientation relative to the bone plate that is consistent with the prescribed trajectory of the access channel. Further, before attaching the bone plate to an anterior vertebral surface, the method may include exposing one or more vertebral bodies in a spinal column by anterior incision. Further still, after performing the medical procedure, the method may include leaving the bone plate attached to the vertebral body.
[0037] In some embodiments of the method, after engaging the trajectory control sleeve to the bone plate, the method may include inserting a radiopaque locating device into the trajectory control sleeve device, radiographically observing the locating device and determining therefrom an extrapolated trajectory of the access channel toward the posterior surface of the vertebral body, and verifying that the extrapolated trajectory is consistent with the prescribed trajectory such that the point of exit at the posterior surface is proximal to the targeted site of interest.
[0038] In some embodiments of the method, after engaging the trajectory control sleeve to the bone plate, the method may include inserting a depth-measuring device into the trajectory control sleeve device to establish an optimal depth of penetration of the bone-cutting tool into the vertebral body, the depth being influenced by the disposition of the bone plate against a variable topography of the anterior surface of the vertebral body.
[0039] In some embodiments, after the completing the medical procedure through the access channel, the method further includes repairing the access channel with an implantable bone repair device, the device having an external geometry complementary to the internal geometry of the channel. In typical embodiment of the method, repairing the access channel includes implanting the bone repair device through the bone plate and into the channel. And in some of these embodiments, the method includes securing a proximal portion of the bone repair device to the bone plate.
[0040] In some embodiments of the method, repairing the access channel includes in-growing bone from the vertebral body into at least a portion of the surface of the bone repair device. And in some embodiments, repairing the access channel includes stimulating bone growth within the bone repair device by providing an osteogenic agent within the repair device.
[0041] In some embodiments of the method, repairing the access channel includes placing a portion of harvested native bone tissue within a bone repair device that comprises a porous cage. In these embodiments, the method may further include allowing or promoting intimate contact between the bone tissue within the bone repair device and bone tissue of the vertebral body. The method may further include perfusing at least some bone tissue or bone-associated biological fluid from the bone repair device into the vertebral body. Still further, the method may include healing together the harvested native bone tissue within the bone repair device and bone tissue of the vertebral body.
[0042] In some embodiments of the system, the bone plate and the trajectory control sleeve are an integrated or integrally-formed device. In this embodiment, thus the system includes a bone cutting tool with a cutting element and an integrated device comprising a bone plate portion and trajectory control sleeve portion. The bone plate portion is configured to be secured to an anterior surface of the vertebral body and has an opening sized to receive the cutting element. The trajectory control sleeve portion has a cylinder configured to receive the cutting element of the bone cutting tool, and the integrated device is configured to guide the bone cutting tool to form the access channel with a prescribed trajectory from the anterior entry to the prescribed posterior opening.
[0043] A method for performing a procedure through a vertebral body overlaying a site in need of a medical procedure with the integrated device summarized above includes attaching the integrated device on an anterior surface of the vertebral body, inserting a bone cutting tool through the trajectory control sleeve portion of the device, forming an access channel through the vertebral body by removing bone with the bone cutting tool, the access channel prescribed as summarized above, disengaging the integrated device from the bone plate, and performing the medical procedure through the access channel and the opening on the posterior surface of the vertebral body.
[0044] In some embodiments of the system and method, the bone plate or integrally formed bone plate portion does not lie directly over the anterior entry location for the access channel. Rather, the bone plate or bone plate portion is attached to the anterior surface of the vertebral body adjacent to the entry location, and supports a trajectory control sleeve or sleeve portion which may be located adjacent to the entry location.
BRIEF DESCRIPTION OF THE FIGURES
[0045] FIG. 1 is a view of an implantable bone plate device viewed from an anterior perspective.
[0046] FIG. 2 is a view of an implantable bone plate device viewed from a posterior perspective.
[0047] FIGS. 3A and 3B provide views of a trajectory control sleeve attachment. FIG. 3A shows a trajectory control sleeve in a side view.
[0048] FIG. 3B provides a side cross-sectional view of the trajectory control sleeve, showing how the angle of the sleeve relative to its base forms an asymmetrical opening in the base.
[0049] FIG. 3C shows the trajectory control sleeve from a proximally-directed perspective.
[0050] FIG. 4 is an anterior perspective of the trajectory control sleeve mounted to an implantable bone plate.
[0051] FIG. 5 is a lateral view of the trajectory control sleeve mounted to an implantable bone plate.
[0052] FIG. 6 is a perspective view showing an implanted bone plate screwed a vertebral body and with a trajectory control sleeve mounted thereon.
[0053] FIG. 7 is an anterior view showing an implanted bone plate screwed to a vertebral body and a trajectory control sleeve mounted thereon.
[0054] FIG. 8 is a lateral view showing an implanted bone plate screwed to a vertebral body and with a trajectory control sleeve mounted thereon.
[0055] FIGS. 9A-9B show various views of a trajectory pin and a drill depth gauge. FIG. 9A is a perspective view of a trajectory pin and a drill depth gauge assembled together
[0056] FIG. 9B is a perspective view of an embodiment of the depth gauge sub-assembly.
[0057] FIG. 10 is a lateral view of the trajectory pin assembly shown in FIG. 9A engaged in a trajectory control sleeve.
[0058] FIG. 11 is a cross sectional view showing a trajectory pin in full engagement with vertebral bone and a trajectory control sleeve.
[0059] FIG. 12 is an anterior perspective view of a trajectory pin and depth gauge engaged within a trajectory control sleeve.
[0060] FIG. 13 is a cross section view showing a bone drill in position relative to a bone plate and trajectory control sleeve prior to cutting bone tissue.
[0061] FIG. 14 is a perspective view of a bone plate after drilling has been completed and the trajectory control sleeve has been disengaged from the implanted bone plate.
[0062] FIG. 15 is a perspective view of a spinal repair implant in the pre-insertion position relative to the implanted bone plate.
[0063] FIG. 16 is a perspective view of a spinal repair implant installed into an access channel through an implanted bone plate.
[0064] FIG. 17 is an anterior perspective view of an alternate embodiment of an implantable bone plate.
[0065] FIGS. 18A and 18B are views of the trajectory control sleeve mounted on the bone plate embodiment of FIG. 17 . FIG. 18A shows the trajectory control sleeve and bone plate from distally directed perspective.
[0066] FIG. 18B shows the trajectory control sleeve and bone plate from a side view.
[0067] FIG. 19 shows an implantable bone plate in situ on a vertebral surface.
[0068] FIG. 20 shows a perspective view of an implantable bone plate and trajectory control sleeve in situ on the vertebra surface.
[0069] FIG. 21 shows a drill cutter engaging vertebral bone tissue through the trajectory control sleeve.
[0070] FIG. 22 shows an access channel through an implanted bone plate and into vertebral bone tissue.
[0071] FIGS. 23 and 24 show an intra-vertebral repair device engaging vertebral bone through the bone plate. FIG. 23 shows the repair device being held by a surgeon immediately prior to inserting into the access channel.
[0072] FIG. 24 shows the surgeon's finger pressing the repair device through the bone plate and into the access channel.
[0073] FIGS. 25A and 25B show views of an intravertebral repair device embodiment with a proximal abutting surface orthogonal to the body of the device. FIG. 25A shows the device from a proximally-directed perspective.
[0074] FIG. 25B shows the device of FIG. 25A from a distally-directed perspective.
[0075] FIGS. 26A and 26B show views of an intravertebral repair device embodiment with a proximal abutting surface canted with respect to main axis of the body of the device. FIG. 26A shows the device from a side view.
[0076] FIG. 26B shows the device of FIG. 26A from a proximally-directed perspective.
[0077] FIGS. 27A and 27B show views of an intravertebral repair device embodiment with a convex external profile, wider in its central portion, narrower at proximal and distal ends. FIG. 27A shows the device from a proximally-directed perspective.
[0078] FIG. 27B shows the device of FIG. 27A from a distally-directed perspective.
[0079] FIG. 28 shows the primary components of an exemplary system associated with the creation and repair of the intra-vertebral access channel.
[0080] FIG. 29 shows a typical access channel that may be produced with the inventive systems and methods.
[0081] FIG. 30 shows a cross sectional view of an access channel being formed in a vertebral body with a hollow cutting tool, a trephine, which forms an access channel with a removal bone plug.
[0082] FIG. 31 shows an exploded view of a bone repair device with a porous body configured to hold bone tissue, and to allow compression of the tissue upon closing the porous body.
[0083] FIG. 32 shows a cut away cross sectional view of the bone repair device of FIG. 31 in assembled form.
[0084] FIG. 33 shows an external view of the assembled bone repair device of FIG. 33 with bone tissue and associated fluid being extruded under pressure.
[0085] FIG. 34 shows an alternative embodiment of an assembled bone repair device with a porous body and with an internal pressure-amplifying feature.
[0086] FIG. 35 shows a bone repair device with a porous body containing bone tissue poised in a position from where it is about to be implanted in an access channel within a vertebral body.
[0087] FIG. 36 shows the bone repair device of FIG. 35 implanted in the vertebral body, and locked into a bone plate.
[0088] FIG. 37 shows a lateral cross sectional view of a bone repair device with a porous body containing bone tissue, in situ, within an access channel in a host vertebral body.
DETAILED DESCRIPTION OF INVENTION
[0089] An inventive surgical system and associated method of use are provided for transcorporeal spinal procedures that create and use an anterior approach to an area in need of surgical intervention, particularly areas at or near a site of neural decompression. Removal or movement of a source of compressing neural pathology is achieved via a surgical access channel created through a single vertebral body instead of through a disc space or through an uncovertebral joint (involving 1 or 2 vertebrae). The access channel has a specifically prescribed trajectory and geometry that places the channel aperture at the posterior aspect of the vertebra in at or immediately adjacent to the targeted compressing pathology, thus allowing the compressing neural pathology to be accessed, and removed or manipulated. The access channel is formed with precise control of its depth and perimeter, and with dimensions and a surface contouring adapted to receive surgical instruments and an implanted bone repair device.
[0090] The channel may be used to access and operate on the compressing pathology, more particularly to remove or to move a portion or the whole of a herniated disc, an osteophyte, a thickened ligament, a tumor, a hematoma, a degenerative cyst, or any other compressing pathology. As a part of the procedure, the posterior longitudinal ligament posterior to the transcorporeal access channel may be opened or removed through the access channel, thereby permitting the visualization or removal of any compressing pathology otherwise obscured by the ligament.
[0091] The invention preserves native bone and disc tissue that is sacrificed by prior art procedures, and further preserves the natural motion of the vertebral joint. The procedure also preserves at least the anterior half of the vertebral endplate of the vertebral body upon which the cutting occurs. Removal or the movement of the compressing pathology can proceed even when a portion of the compressing pathology resides beyond the limits of the transcorporeal access channel. Further, removal of the compressing pathology may occur without inducing posterior or inward compression on the dura mater protective layer surrounding the spinal cord and exiting nerve roots, or exerting direct pressure on the spinal cord or exiting nerve roots. Also, the compressing pathology removal may occur without lacerating the dura mater protective layer surrounding the spinal cord and exiting nerve roots.
[0092] Embodiments of the system and method also pertain to therapeutic occupation and repair of the vertebral body void created by making such an access channel. This repair is achieved by inserting an implantable vertebral repair device that has a conformation complimentary to the internal geometry of the access channel after the procedure is complete, and by securing the implant in the inserted position by means of a vertebral bone plate. The external surface of the vertebral repair device is in substantial contact with the internal surface of the access channel after insertion is complete, thereby substantially restoring structural and mechanical properties of the vertebrae. Such repair occurs without directly or indirectly inducing compression of underlying dura mater or neural structures. The repair further occurs without the subsequent anterior migration of the vertebral repair device, which could cause injury to soft tissue structures located anterior to the spine.
[0093] In some embodiments, the implanted device has a bioabsorbable composition that allows replacement of the implant device by in-growth of native bone tissue, or which is incorporated into the native bone tissue. As a whole the system increases the objectivity of considerations associated with spinal surgery, reduces patient risk, and contributes to better and more predictable surgical outcomes.
[0094] Various aspects and features of the invention will now be described in the context of specific examples and with the illustrations provided by FIGS. 1-37 .
[0095] A number of tools and instruments are included in or used within the system and methods described herein. FIG. 28 shows some of these system elements: an implantable vertebral plate 100 , a cutting tool guide 200 , a confirmation device or depth gauge 300 , a collar 310 for the confirmation device, a cutting tool 400 , an implantable device 500 , and an implant locking device 600 .
[0096] An implantable vertebral plate 100 is adapted to attach to the anterior surface of a vertebra. A trajectory control sleeve 200 is adapted to detachably mount the implanted bone plate 100 to establish the entry point, trajectory, and depth of an access channel created through the vertebral body. A confirmation device 300 is adapted to temporarily engage the cutter tool guide for the purposes of confirming placement of the trajectory control sleeve on the correct vertebra, for visualizing the projected trajectory of the bone cutting device, and for measuring the actual distance between the trajectory control sleeve and the anterior bone surface so as to accurately and predictably penetrate through the vertebra without impinging on the dura-mater or other neural tissue at the posterior aspect of the channel. The pin-shaped confirmation device 300 is typically radio-reflective or radiopaque, thus allowing confirmation of all geometries on a surgical radiograph taken prior to the excision of any tissue.
[0097] A cutting tool 400 is generally adapted to remove bone material and create the vertebral access channel; the tool 400 has the precise cutting geometry necessary to produce the prescribed access channel geometry within the vertebral bone. The access channel provides various forms of advantage for aspects of procedures as described further below.
[0098] A surgical cutting instrument is used to open or partially remove the posterior longitudinal ligament which can obscure a view of the pathology of interest, but becomes observable by way of the access channel. A cutting tool used to remove osteophytes (bone spurs) at or adjacent to the base of the vertebral body can be approached by way of the access channel proximal to the neural elements to be decompressed. An instrument for grasping or moving herniated disc material or other compressing pathology can be provided access to the site located at or near the base of the access channel.
[0099] An implantable bone repair device 500 is adapted repair the vacant vertebral volume created by the formation of the access channel.
[0100] An implant locking device 600 is adapted to retain the implant in the desired position. The locking device is adapted to positively engage the anterior surface of the repair implant and engagably lock it in place with respect to the implanted bone plate device 100 . Fasteners such as elements 600 and 900 (seen in later figures) are applied to retain a bone plate or locking cap (see in other figures) in a desired position.
[0101] Each of these aforementioned system elements and their role in surgical procedures on the spine are described in further detail below.
[0102] FIGS. 1 and 2 show anterior and posterior views, respectively, of an implantable transcorporeal bone plate device 100 with a first or anterior facing surface 101 and a second or posterior facing surface 102 , the posterior facing surface being configured to be proximal or in contact with the anterior surface of a vertebral body after implantation. The device further has one or more holes 103 that form an aperture between surfaces 101 and 102 to accommodate and secure retention screws there to secure the device 100 to vertebral bone.
[0103] Embodiments of implantable bone repair described and depicted herein are may include a multiple number of orifices, as for example, for inserting attachment elements, or for viewing, that have various sizes and typically are circular or ovular in form. These are merely exemplary forms and profiles of openings which may vary depending on particulars of the application of the device, such that size and profile may vary, and for example, by taking the form of any of circular, trapezoidal, multilateral, asymmetrical, or elongated openings.
[0104] The device also has a passage 104 for receiving and detachably-engaging a bone cutting guide device such as a drill or ream. The device 100 further may have one or more engaging features 105 configured to receive and engage a corresponding feature on the trajectory control sleeve in a manner that prevents relative motion of the trajectory control sleeve and its accidental disengagement from the implanted bone plate. The device may have one or more protrusions 106 on the posterior surface ( FIG. 2 ), the protrusions being adapted to impinge into or through the cortical bone so as to increase the stability of the implant on the bone and to allow for temporary placement of the device prior to insertion of the bone screws through the opening 103 . Protrusions 106 further act to stabilize the bone implant and to transfer loads around the vertebral access channel after a surgical procedure is complete, thereby further reducing the risk of bone fractures or repair device expulsion.
[0105] FIGS. 3A-3C show a side view and perspective view, respectively, of an embodiment of a trajectory control sleeve 200 for a bone cutting tool, a rotary cutting tool, for example, such as a drill, burr, reamer, or trephine. FIG. 3A shows a trajectory control sleeve in a side view, while FIG. 3C shows the trajectory control sleeve from a proximally-directed perspective. The trajectory control sleeve 200 has an internal cylinder 202 there through to allow passage of a bone-cutting tool, such as a drill or trephine, and to establish and control the angle α of penetration of the drill through a vertebral body. As seen in FIG. 3B the angle α refers to the angular difference from a right angle approach with respect to the plane formed by an implantable bone plate 100 to which the trajectory control sleeve is engaged. More specifically, angle α can represent a compound angle according to a cranio-caudal axis and a medial lateral axis with respect to a reference plane tangential (such as would be represented by an implanted bone plate) to the access channel entry on the anterior surface of vertebral body. The angle α is prescribed by a physician by making use of radiographic images of the spine that focus on the target vertebrae and the underlying pathology that are the subject of surgical or diagnostic interest. Such procedures are typically performed prior to surgery, and they may be repeated after the bone plate is attached to the surgical site. FIG. 3C provides a cross sectional view of an exemplary control sleeve 200 , which shows the tilt of the annular ring 203 in accordance with angle α, and the consequent off-center opening at the base of the trajectory sleeve, which generally aligns with the base of the bone plate when the two components are engaged.
[0106] In some embodiments of the system and method, a transcorporal access channel is formed using a trephine type device such as those provided by Synthes, Inc (West Chester Pa.), which offers particular advantages. The trephine device produces a cylindrical channel through the vertebral bone while maintaining the core to be removed in an intact state. The core can be removed from the trephine after the tool itself has been removed from the vertebral body, and the bone tissue can be subsequently re-used as graft volume after the surgical procedure is completed.
[0107] Trajectory control sleeve 200 has a surface 201 adapted to be in intimate contact with and be co-planar to an anterior facing surface 101 of a bone plate implant device 100 (after engaging the device, as in FIG. 4 ) so as to assure that the axial distance d is well established and controlled. The trajectory control sleeve 200 further has an annular abutting surface 203 surrounding the opening of the internal cylinder 202 , the surface being adapted to positively engage a corresponding feature such as a flange or collar of the drill so as to prevent its over-penetration into the vertebral body. This abutment may be internal or external to the guide device as shown in FIG. 4 and FIG. 3A respectively. Trajectory control sleeve 200 also has an engaging and interlocking feature 204 adapted to detachably-engage a corresponding feature 105 (see FIG. 5 ) on the implantable bone plate 100 . The trajectory control sleeve 200 is further generally adapted to protect surrounding vascular and soft tissue from accidental injury or cutting by providing a solid protective sheath around the sharp edges of the drill while it is operating.
[0108] FIGS. 4 and 5 show a perspective view and side view, respectively, of trajectory control sleeve 200 and an implantable bone plate 100 in their mutually interlocked positions. FIG. 4 shows the internal cylinder 202 for providing access, guiding and controlling the penetration of a drill into vertebral bone. FIG. 4 further shows an alternate embodiment of the device that has an abutting surface 203 , in which the abutting surface is internal to the trajectory control sleeve. FIG. 5 shows the planar engagement of the anterior surface of an implanted bone plate 101 with the corresponding surface 201 of the trajectory control sleeve. This engagement establishes a reference plane 210 from which angle α and distance d are controlled and referenced relative to the vertebral body. FIG. 5 further shows the engagement of the detachable locking features 205 of the trajectory control sleeve and of the bone plate 105 .
[0109] FIGS. 6-8 relate to the placement of a mutually-engaged bone plate 100 and a trajectory control sleeve 200 to a vertebral body 230 , in preparation for creating an access channel through the vertebral body. FIG. 6 provides a surface perspective view of bone plate 100 in an implanted position on a vertebral body 230 , the plate secured by a bone screw 900 , and further shows trajectory control sleeve 200 in its engaged position on the bone plate 100 . FIG. 7 shows an anterior view of a bone plate 100 and trajectory control sleeve 200 mutually engaged and, the engaged assembly in it installed position on vertebral body 230 . A bone screw 900 is inserted at or near the medial centerline 231 of the vertebral body 230 , thus positioning the center point 220 of the trajectory control sleeve cylinder at a prescribed distance l from the centerline. As seen in FIG. 8 , an angle β is the compliment to angle α shown in FIG. 5 . After installation of the bone plate implant 100 on a vertebral body 230 , the reference plane 210 may be delineated relative to the vertebral body 230 and as a baseline reference for the angle and depth of drill penetration into the vertebral body.
[0110] FIGS. 9A and 9B show a pin or plug type confirmation device 300 used for confirming vertebral position prior to excision of bone or other tissue and a collar 310 into which the confirmation device is inserted. A standard procedure in spinal surgery is to insert a radiographically reflective screw or pin into the vertebral body and to take an x-ray of the cervical spine prior to beginning any procedure so as to assure that the procedure is being performed at the correct vertebral level. In the embodiment described the confirmation device 300 is slidably inserted within the internal diameter of the control sleeve 200 and progressed axially therethrough until the proximal end of the device 300 is in contact with the anterior surface of the vertebral body. A radiographic image is taken inter-operatively and reviewed prior to the excision of any vertebral bone tissue. The examination includes an extrapolation of the trajectory through the vertebral body so as to confirm that the actual point of exit at the posterior surface of the vertebra is at the surgically prescribed location. Further, the axial distance from the both the anterior and/or posterior surfaces of the vertebra are measured and used as references to control the depth of bone cutting necessary to produce the access channel and to prevent over penetration into the dura mater or neural tissue. In some instances the device 300 may be used during the bone cutting procedure as a checking device to determine the actual progression of the channel across the vertebra.
[0111] FIG. 9B shows a trajectory confirmation pin 300 and a collar 310 that slidably-engages the external diameter of the pin by way of features 320 that engage complementary features 321 on the internal diameter of the collar. In this exemplary embodiment, the trajectory pin features 320 are convexities that are complementary to concave collar feature 321 . Collar 310 can slide axially along the length of the pin diameter 320 and frictionally-engage the pin diameter in a manner that requires an axial force to be applied to the collar to induce axial movement. Collar 310 has a surface of engagement feature 330 that is adapted to make intimate contact with the annular surface 203 of the trajectory control sleeve when the pin is inserted into the trajectory control sleeve. Once surfaces 203 and 330 are engaged, insertion force F ( FIG. 9A ) applied by a surgeon causes pin 300 to travel axially through the internal diameter of collar 340 , increasing the distance L 2 between point 350 on the tip of the pin and the control surface 330 of the collar 310 .
[0112] FIGS. 10-12 relate to the use of a trajectory confirmation pin 300 , a collar 310 , and trajectory control sleeve 200 in the context of a bone plate 100 in place, as implanted in a vertebral body 230 . An embodiment of a pin device 300 is temporarily inserted into the internal cylinder of the trajectory control sleeve 200 and an x-ray is taken. The x-ray confirms the location of the vertebral body 230 and an anterior-to-posterior extrapolation along the centerline of the device through the image of vertebral body indicates the trajectory of the drill or cutting tool and the projected point of exit at or near the posterior longitudinal ligament. Angular and distance measurements may be made using the radiograph, and if adjustments are required, the surgeon disengages the trajectory control sleeve and installs another device with the desired geometry.
[0113] FIG. 11 shows the confirmation pin 300 at its maximum depth of penetration through the transparently rendered trajectory control sleeve 200 and bone plate implant 100 . In this position, tip 350 of the pin device is in intimate contact with the surface of the vertebral bone 230 . Because of the mechanical engagement of the collar 310 on the external surface, the collar remains in position relative the bone-contacting tip of the pin 350 . Upon removal of the pin, distance L 2 (see FIG. 9A ), as measured between the collar surface 330 and the pin contact tip 350 , provides a reference dimension with which the penetrating depth of the bone drill can be controlled by setting a mechanical stop that engages the annular surface 203 of the trajectory control sleeve. For ease of use, the surface of the confirmation pin 300 may have linear graduations.
[0114] FIG. 13 shows a bone cutting tool 400 , such as a drill, burr, or reamer, inserted through the trajectory control sleeve 200 and the bone plate implant 100 with the tip of the cutting tool 420 at the initial point of contact on the vertebral body. Cutting tool 400 has a mechanical stop 450 . The distance D 4 from the drill tip 420 to the lower surface 430 of the drill stop 450 , is a prescribed dimension equivalent to the measured distance L 2 (see FIG. 9A ) plus the desired depth of penetration into the vertebral body, such depth being established by the surgeon through radiographic analysis.
[0115] FIG. 14 shows a surgical access channel 470 in a vertebral body 230 , as viewed through the bone plate implant 100 after drilling has been completed and the trajectory control sleeve has been removed from the plate. After removal of the trajectory control sleeve, a neural decompression or other surgical procedure is performed through the access channel. On completion of the procedure, an intra-vertebral bone implant 500 is inserted ( FIGS. 15 and 16 ) into access channel 470 to fill an close it, restore mechanical strength and stability to the host vertebral body 230 , and to provide a medium within the vertebral body suitable for osteogenesis.
[0116] In some embodiments of the invention, the intra-vertebral access channel 470 ( FIG. 14 ) of an implantable bone plate has a diameter of about 5 mm to about 8 mm. This size creates a surgical field that is sufficiently open enough for typical procedures, and is sufficiently large enough to minimize the possibility that the access channel will not intersect the area of neural compression. In some embodiments, the angle of entry α provided by the access channel is about 10-30 degrees, with the center of the point of entry being generally at mid-point on the cranio-caudal length of the vertebra. While these dimensions are typical, alternative embodiments of bone plate implants may have varying widths and geometries so as to accommodate wide anatomical variations. In various alternative embodiments, trajectory control sleeve devices also may include a wide range of angles and depths for the same reason.
[0117] With a combination of the angle of entry, the point of entry into the vertebral body, and the size of drill used to create the access channel 470 , some embodiments may result in a penetration of the posterior disc space in the posterior 20%-30% of the disc volume 480 , leaving the vertebral end plate 490 and the native disc tissue 495 substantially intact. FIG. 29 illustrates a typical access channel 470 that may be formed using a 6 mm drill diameter, about a 10 degree angle of entry, with an entry point on the cranio-caudal centerline of the vertebral body.
[0118] FIG. 15 shows an intra-vertebral implantable bone repair device 500 positioned for implantation within the vertebra 230 through the bone plate implant 100 . Various embodiments and features of a bone repair device are described in U.S. Provisional Patent Application No. 60/990,587 of Lowry et al. (filed on Nov. 27, 2007, entitled “Methods and systems for repairing an intervertebral disk using a transcorporal approach”), which is incorporated herein in its entirety by this reference. In the embodiment shown, implant 500 has an abutting surface 520 adapted to engage with a corresponding surface of the bone plate implant. This arrangement prevents excess penetration of the implant through the access channel and prevents the implant from compressively engaging neural elements. FIG. 16 shows the implantable device 500 in the final installed position relative to the bone plate 100 . The device 500 has a locking mechanism 510 , such as a conventional bayonet mount, for engaging the bone plate in order to prevent migration of the implant within or out of the access channel.
[0119] FIG. 17 shows an alternative embodiment 620 of an implantable bone plate as previously described and shown in FIGS. 1 and 2 . In this present embodiment, bone plate 620 has a larger lateral dimension to accommodate particular anatomies that may be encountered, including those of patients, for example, with small stature, degenerative bone conditions, or osteophytes or other abnormalities that may require alternate fixations. To assure accurate location of the device relative to the medial centerline of the vertebra, implant device 620 may include a viewing port 650 or some other positioning indicator. FIGS. 18A and 18B show anterior perspective and side views, respectively, of the engagement of a trajectory control sleeve 200 , as previously described, with the alternative bone implant device embodiment 620 .
[0120] In another alternate embodiment, an implantable bone plate and bone cutting device may be formed as a unitary device and temporarily fixed to the vertebral body. In this embodiment an intra-vertebral access channel is created using the temporarily implanted device; subsequently, the device is removed, the surgical procedure performed, and the access channel repaired using the intra-vertebral implant as previously described. In this embodiment, a bone cutting device may have a least two cutting diameters or widths, the first being that necessary to produce the access channel, the second being a larger diameter configured to remove an annulus of bone on the anterior vertebral surface so as to provide an abutting surface against which the implant would rest in order to prevent over-penetration of the intra-vertebral repair implant within the vertebra.
[0121] FIGS. 19-24 show exemplary devices being put to exemplary use to evaluate the practical viability, fit, and the functionality of methods for their use. FIG. 19 shows an implantable bone plate 100 in situ on a vertebral surface 230 . FIG. 20 shows a perspective view of the implantable bone plate and trajectory control sleeve 200 in situ on the vertebral surface. FIGS. 21-24 include a view of surgeon's finger to show scale and feasibility of manual manipulation of elements of the inventive system. FIG. 21 shows a bone cutting tool 400 engaging vertebral bone tissue through the trajectory control sleeve 200 . FIG. 22 shows an access channel 470 through the implanted bone plate and into vertebral bone tissue. FIG. 23 shows an intra-vertebral repair device 500 being readied for engaging vertebral bone through the bone plate 100 .
[0122] FIGS. 25A-27B show embodiments of alternative external geometries of the intra-vertebral implantable devices 500 as may appropriate for particular patients or procedures. FIGS. 25A and 25B show views of what may be considered a default embodiment of an intravertebral repair device with a proximal abutting surface orthogonal to the body of the device. FIG. 25A shows the device from a proximally-directed perspective, while FIG. 25B shows it from a distally-directed perspective. FIGS. 26A and 26B show and embodiment wherein abutting surface 520 is canted at an angle not orthogonal to the central axis of the device 500 . FIGS. 27 a and 27 b show an intra-vertebral implant device 500 with a convex external profile where dimension D 4 is nominally larger than the internal diameter of the access channel so as to compressively engage the cancellous bone tissue. Such a compressive engagement can improve the interference fit of the device therein and to inter-diffuse cancellous bone tissue within the implant volume to improve osteogenesis.
[0123] FIG. 28 shows an assemblage of some of these system elements, and was described at the outset of the detailed description; shown is an implantable vertebral plate 100 , a cutting tool guide 200 , a confirmation device or depth gauge 300 , a collar 310 for the confirmation device, a cutting tool 400 , an implantable device 500 , and an implant locking device 600 . FIG. 29 provides an exemplary embodiment of the invention that was discussed earlier in the context of the formation of an access channel, in conjunction with associated description of FIGS. 14-16 .
[0124] Implantation of the patient's own bone tissue (an autologous graft) is a generally advantageous approach to repairing bone, as autologous grafting typically yields high success rates and a low rate of surgical complications. Accordingly, some embodiments of the invention include using core bone tissue harvested from the forming of the access channel, and implanting the plug, intact, in the form of bone repair graft. An advantage to recovering and making use of bone derived from the channel includes the absence of a need to harvest bone from a second site. Embodiments of the invention, however, do include harvesting bone from secondary sites on the patient, such as the iliac crest, as may be appropriate in the practice of the invention under some circumstances. In some embodiments, for example, it may be advantageous to supplement bone derived from the access channel with bone from other sites. In still other embodiments, under various clinical circumstances, it may be appropriate to make use of bone from donor individuals. Bone from other autologous sites or other donor individuals may be used as a repair device in the form of an appropriately formed plug, or bone may be fragmented or morselized, and packaged as a solid plug, or bone may be included as a preparation provided in a porous cage, as described further below.
[0125] Some embodiments of methods provided make use of a trephine type bone cutting system, as noted above. With a trephine bone cutting system, the external diameter of the bone tissue core is about equal to the internal diameter of the trephine device, while the internal diameter of the access channel is about equal to the external diameter of the device. Thus, a trephine-derived bone plug from forming the access channel provides an appropriately-sized piece to be inserted into the channel for repair and healing, but does not necessarily make intimate contact with the inside surface of the channel due to the width of the kerf created by the trephine.
[0126] Optimal healing and recovery from implantation of bone material into an access channel occurs when there is an intimate or compressive engagement of the graft material with the vertebral bone tissue (substantially cancellous bone), as this intimate association provides for rapid blood profusion and bone healing while providing mechanical support during healing. Accordingly, an embodiment of the bone repair device provided herein includes a device with bone tissue inside a porous cage, as described in detail below.
[0127] The porosity of the cage is a particularly advantageous feature for allowing cell to cell contact through the boundary of the device. To some degree, it may also allow cell migration, however the most advantageous factor in promoting rapid healing is cell to cell contact that initiates sites of tissue unification, which can then spread, stabilize a healing zone around the graft or bone repair device, and ultimately lead to effective fusion and integration of the graft within the host vertebral body.
[0128] A porous cage, as provided by this invention, also has a compressibility, such that when the contents of the cage are subject to a compressive force, however transient and minimal, blood or plasma and bone cells that are present in the harvested cancellous bone are forced outward into the environment within and around the access channel site. Extrusion of biological fluid in this manner, advantageously packs bone tissue closer together within the cage, and bathes the periphery of the graft and the host-graft intersectional zone with a medium that is optimal for exchange of dissolved gas and nutrients that are critical in the initial stages of healing. Some embodiments of the invention include bathing the bone tissue preparation in a supportive liquid medium before implantation. Such bathing may occur prior to placing the bone tissue preparation in the porous cage and/or after placing the preparation in the cage. The liquid medium may be any appropriate cell culture medium, and may be further supplemented with biological agents, such as osteogenic agents or other growth factors.
[0129] Embodiments of the implantable porous cage bone repair device, as provided herein, encapsulate the bone tissue contained therein, and provide mechanical stability to the access channel during healing. These embodiments compensate for the volumetric loss associated with the bone cutting process of the trephine and promote contact between the bone volume within the device and the surrounding vertebral bone tissue. The device, as a whole, and like other bone repair embodiments provided, cooperates with the implanted bone plate so that the orientation and penetration depth of the implant device within the access channel may be controlled. These forms of control assure that the device does not over-penetrate through the channel, thereby compressing the dura mater or neural elements within the vertebra, and assuring that the implanted device cannot migrate in an anterior direction out of the access channel.
[0130] Exemplary embodiments of the porous cage device and associated method of use will now be described in further detail, and in the context of FIGS. 30-37 .
[0131] FIG. 30 provides a cross-sectional view of a vertebral body 809 with a bone plate 801 attached to the anterior bone surface 810 . Mounted on the bone plate is a trajectory control sleeve 802 cooperating with the bone plate 801 to establish and control the trajectory of a bone cutting tool 804 with a cutting surface 808 through the vertebral body to direct the trajectory of the formed access channel to a prescribed point of exit at the posterior surface of the vertebra 820 , in the locale of a site of medical interest.
[0132] The depicted exemplary bone cutting tool 804 is a hollow bone cutting tool, a trephine, with an external diameter 805 selected to be complementary to the internal diameter of the trajectory control sleeve 802 , and to cooperate therewith so as to assure that the centerlines of the bone cutting tool and the trajectory control sleeve are substantially co-incident during the bone cutting process. The trephine 804 progresses through the vertebral body 820 from an anterior to posterior direction until the cutting surface 808 penetrates the cortical bone at the posterior surface of the vertebra proximal to the spinal cord 850 . Upon removal of the trephine from within the vertebral body, a core of bone tissue within the interior of the trephine is extracted from the wound opening, thus creating or exposing an open access channel from the anterior surface of the vertebral body to the neural elements and the prescribed site of medical interest immediately behind the posterior wall of the same vertebral body.
[0133] FIG. 31 shows components of an exemplary bone repair device in a linearly exploded view from an external perspective. At the top, a cap 950 is above a vertebral bone core 860 ; the bone core is positioned for placement in a porous cage 900 . FIG. 32 is a cross-sectional view of the fully assembled device 905 . According to the inventive method, the vertebral bone core 860 is placed within an implantable intravertebral bone repair device 900 with a porous wall, and encapsulated by a cap or closing element 950 . In this exemplary embodiment the cap has a screw thread 951 disposed to engage a mating thread 901 on the body 900 of the implantable device; the cap further has a compression element 952 disposed to exert a compressive force F on the bone graft core 860 when the cap is being closed on the body 900 of the repair device, and consequently inducing extrusion of native tissue within the device, through open pores 902 contained within the perimeter wall of the implant device. As described above, the bone tissue placed within the body of the repair device is not necessarily an integral bone plug intact from the trephine used to form the channel; the bone tissue may be a fragmented or morselized preparation, it may include bone from another site on the patient, and it may include bone from another donor.
[0134] FIG. 33 provides an external perspective view of an assembled bone repair device 905 . This view captures a moment shortly after the cap 950 has been closed, and by such closing has increased the pressure on the bone tissue contained within the device. By virtue of this elevated pressure within the porous walled body 900 , bone core graft tissue and associated biological fluid are extruding through the porous perimeter wall. In some embodiments of the method, the cap 950 is closed on the porous body 900 of the repair device immediately prior to insertion of the assembled device 905 into the access channel within the host vertebral body, and in some embodiments of the method, the cap is closed after insertion of the porous body 900 , thereby forming the complete assembly 905 in situ.
[0135] FIG. 34 shows a cross sectional view of an alternate embodiment of the porous body portion 900 ′ of an assembled repair device 905 ′ that includes an internal tissue expander feature 920 disposed to induce radial extrusion of the bone core tissue through the orifices.
[0136] FIGS. 35 and 36 show similar views of the porous cage device embodiment 905 as were provided earlier by FIGS. 15 and 16 for solid bone repair device 500 embodiments. FIG. 37 shows a cross sectional view of the implanted device 905 within an intravertebral access channel 470 . Upon completion of the surgical procedure through the access channel, the bone repair implant assembly 905 (containing the harvested bone graft core 860 ) is introduced into the transcorporal access channel through the aperture 830 in the implanted bone plate device 100 . In one exemplary embodiment, the bone repair assembly 905 has an abutting surface disposed to cooperate with a mating surface of engagement 871 on the bone plate implant. The completed mating of the bone repair assembly 905 with the bone plate 100 prevents the distal tip 890 of the implant assembly from penetrating into the spinal cord volume posterior to the vertebral body.
[0137] The implantable repair device assembly 905 further has an orientation and locking feature 951 disposed to engage a mating feature 950 on the implantable bone plate 100 so as to control the radial orientation of the implant with respect to the bone plate and to lockably engage the bone repair implant device with the bone plate implant so as to prevent migration or expulsion of the bone repair implant assembly 905 out of the access channel. Such radial orientation of the implant relative to the access channel may be particularly advantageous when the bottom or distal end of the repair device body 900 is formed at an angle (not shown) to completely fill the access channel.
[0138] As a consequence of the implantation of the bone repair assembly 905 within the access channel, the general mechanical integrity of the vertebral body has been restored, the internal void of the access channel has been filled in a manner such that native disc material 980 cannot migrate into the channel, bone tissue (typically autologous) has been re-implanted in a manner that establishes intimate contact between the bone graft and the cancellous bone of the vertebra thereby promoting blood profusion and rapid bone healing.
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A system and method are provided for making an access channel through a vertebral body to access a site of neural compression, decompressing it, and repairing the channel to restore vertebral integrity. System elements include an implantable vertebral plate, a guidance device for orienting bone cutting tools and controlling the path of a cutting tool, a bone cutting tool to make a channel in the vertebral body, a tool for opening or partially-resecting the posterior longitudinal ligament of the spine, a tool for retrieving a herniated disc, an implantable device with osteogenic material to fill the access channel, and a retention device that lockably-engages the bone plate to retain it in position after insertion. System elements may be included in a surgery to decompress an individual nerve root, the spinal cord, or the cauda equina when compressed, for example, by any of a herniated disc, an osteophyte, a thickened ligament arising from degenerative changes within the spine, a hematoma, or a tumor.
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BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a shock absorber for absorbing a shock of a moving member in case the moving member, such as work, is transferred from a moving state to a stopping state.
In a conventional shock absorber, oil is used, as shown in FIG. 8 of Japanese Patent Application No. 2000-153832 (corresponding U.S. patent application Ser. No. 09/571,593). Thus, there is a disadvantage of oil stain due to the oil leakage and oozing out of oil.
In order to eliminate the above disadvantage, a shock absorber using air has been invented, as shown in, for example, FIG. 1 through FIG. 3 of Japanese Patent Application No. 2000-153832.
FIGS. 7 through 9 generally correspond to FIGS. 1 through 3 of Japanese Patent Application No. 2000-153832, and as an example of a prior shock absorber, a shock absorber in FIGS. 7 through 9 will be briefly explained based mainly on operations thereof. From a state shown in FIG. 7, a moving member W is moved rightward, and a piston shaft 102 pressed by the moving member W slides in a piston bearing 101 a to be displaced rightward, so that a piston 103 provided integrally with the piston shaft 102 compresses air in a cylinder 101 (refer to FIG. 8 ).
In this case, in order to prevent a space between a left end side of the piston 103 and an inner wall of a left side of the cylinder 101 from becoming a vacuum state, air flows to the left side of the piston 103 through an air extracting hole 109 .
As shown in FIG. 8, air compressed by the piston 103 passes through a first air passage 116 , and flows in an arrow direction for a flow quantity determined by a flow quantity control valve formed of a flow quantity control shaft 113 b and a flow quantity control shaft hole 114 of a speed controller section B, and air flows backward to outside or a compressed air tank, not shown, through a second air passage 117 and a tube 118 .
Furthermore, when the piston 103 reaches an inner end portion of the cylinder 101 such that the right end of the piston 103 abuts against a cylinder wall 106 or a contact 105 abuts against a left end of the piston bearing 101 a , the moving member W stops while receiving cushions of air and a compressing coil spring 108 .
When the pressing force of the moving member W against the piston 102 is removed, the piston 103 starts moving leftward by a reactive force of the compression coil spring 108 and an air pressure from the compression air tank (refer to FIG. 9 ).
In this case, as shown in FIG. 9, since air in the second air passage 117 opens a check valve 115 by resisting against the pressing force of the compression coil spring 115 a such that the air in the second air passage 117 is directly sent to the first air passage 116 , a large quantity of air flows in a short time regardless of the flow quantity of air determined by a slit formed by the flow quantity controlling shaft 113 b and the flow quantity controlling shaft hole 114 . Thus, the piston 3 is quickly displaced leftward to restore to the state shown in FIG. 7 .
Incidentally, reference numeral 116 a denotes a groove connecting the first air passage 116 and an air chamber 115 b , and the check valve 115 can be opened without compressing air in the air chamber 115 b.
In the shock absorber using air as described above, as compared to the shock absorber using oil, there might be a case that the force of absorbing a shock is insufficient in order to absorb a movement of the detecting member, and in this case, a larger-scaled shock absorber has to be used.
In view of the foregoing, an object of the invention is to provide a shock absorber, in which a force of absorbing a shock is increased to be equivalent to the shock absorber using oil, and air inside the shock absorber is airtightly confined irrespective of outside air, such that dustproof and waterproof functions are made perfect, and the shock absorber can be used in a clean room.
Further objects and advantages of the invention will be apparent from the following description of the invention.
SUMMARY OF THE INVENTION
To achieve the aforementioned objects, the present invention provides a shock absorber, which comprises: a cylinder having a cylinder chamber; a piston bearing integrally formed at one end of the cylinder to be arranged coaxially therewith; a piston slidably provided in the cylinder chamber and having a piston shaft including a distal end projecting from the piston bearing; a flow quantity control valve disposed at the other side of the cylinder; a check valve disposed at the other side of the cylinder; a through hole bored through a piston to penetrate from a piston bearing side to a side located opposite to the piston bearing; and valve means provided in the through hole. The piston shaft slidably moves in the piston bearing when the distal end thereof is pressed by a moving member, and the piston compresses air in the cylinder chamber when the piston is pushed toward the other end of the cylinder, so that a portion of the cylinder chamber located at a side of the piston bearing is made into a vacuum state.
The flow quantity control valve is provided for controlling a quantity of air flowing between the cylinder chamber and an outside of the cylinder chamber, to thereby control a force of absorbing a shock in case the piston compresses air in the cylinder chamber. The check valve is opened only when air is fed from the outside of the cylinder into the cylinder chamber in case the piston returns to an original position after the piston compressed air in the cylinder chamber, to thereby send a large amount of air rapidly. The valve means opens and closes in accordance with a movement of the piston in the cylinder chamber, to thereby increase the force of absorbing the shock.
Also, the shock absorber includes air storing means provided for storing air passing through the flow quantity control valve outside the cylinder chamber, and the air storing means is sealed to thereby increase the force of absorbing the shock. The sealed air storing means allows air in the shock absorber to be airtightly confined therein. Further, the air storing means has a capacity which is variable.
In addition, in the shock absorber as stated above, the valve means is formed of first valve means and second valve means. The first valve means is opened in case the piston approaches an end surface of the cylinder opposite to the side of the piston bearing, and the first valve means includes a valve operation shaft slidably abutting against the end surface of the cylinder opposite to the side of the piston bearing to thereby open the first valve means. The second valve means is opened only when the piston is moving toward an end surface of the cylinder in the side of the piston bearing.
Also, instead of having the sealed air storing means inside the shock absorber, the shock absorber can be provided with an air passage passing through the flow quantity controlling valve and extending between the cylinder chamber and an outside of the shock absorber. A portion of the air passage projecting outside the shock absorber can be connected to an external air chamber, or a compressed air tank.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 ( a ) is a front sectional view showing a first embodiment of the invention in a state before an operation;
FIG. 1 ( b ) is an enlarged view of a check valve;
FIG. 2 is a front sectional view of the first embodiment showing a state during the operation;
FIG. 3 is a front sectional view of the first embodiment showing a state in the course of returning to an original state after the operation;
FIG. 4 ( a ) is an explanatory side view of a part of a piston as seen from a section taken along line 4 ( a )— 4 ( a ) in FIG. 1 ( a );
FIG. 4 ( b ) is a cross sectional view taken along line 4 ( b )— 4 ( b ) in FIG. 4 ( a );
FIG. 4 ( c ) is a cross sectional view as in FIG. 4 ( b ), showing a state that a first valve is actuated;
FIG. 5 is a front sectional view of a second embodiment of the invention;
FIG. 6 is a front sectional view of a third embodiment of the invention;
FIG. 7 is a front sectional view of a prior shock absorber showing a state before an operation;
FIG. 8 is a front sectional view of the prior shock absorber showing a state during the operation;
FIG. 9 is a front sectional view of the prior shock absorber showing a state in the course of returning to an original state after the operation; and
FIG. 10 is a front sectional view of a fourth embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 ( a ) through FIG. 4 ( c ) show structural views of a first embodiment of the invention, wherein FIG. 1 ( a ) is a front sectional view of a shock absorber of the first embodiment in a condition that a moving member is spaced away; FIG. 1 ( b ) is an enlarged view of a check valve; FIG. 2 is a front sectional view showing a state that a piston is pressed by the moving member to compress air in a cylinder; and FIG. 3 is a front sectional view showing a state in the course of returning of the piston to the original state, that is, the state shown in FIG. 1 ( a ).
FIG. 4 ( a ) is a side view of a part of the piston seen from a section taken along line 4 ( a )— 4 ( a ) in FIG. 1 ( a ); FIG. 4 ( b ) is a cross sectional view taken along line 4 ( b )— 4 ( b ) in FIG. 4 ( a ); and FIG. 4 ( c ) is a view showing a state that the first valve shown in FIG. 4 ( b ) is actuated.
In FIG. 1 ( a ) through FIG. 3, reference numeral 41 denotes a cylinder; 42 is a cylinder head; 43 is a piston bearing; 44 is a piston shaft; 45 is a contact; 46 is a piston; and 47 is a piston ring. The piston 46 and the piston shaft 44 are press-fitted to each other by using a retaining ring 44 a . A ring shape magnet 48 is embedded at a right side of the piston 44 . Reference numeral 49 is a compression coil spring which constantly attracts the piston 46 to a side of the cylinder head 42 .
In a cylinder wall 41 a of a right side of the cylinder 41 , a flow quantity control bearing 50 is fixed by a screw, and a flow quantity control shaft 52 is screwed into a control screw 51 of the flow quantity control bearing 50 . A cone portion 52 a at a left distal end of the flow quantity control shaft 52 and a hole 50 a at a left distal end of the flow quantity control bearing 50 form a throttle, and by turning a control knob 53 , the throttle can be controlled. Reference numeral 54 denotes a double nut for fixing the control knob 53 , and 50 b is an air hole for a bypass.
Numeral 55 is a non-contact switch, which outputs an abutment signal through a lead 55 a when the magnet 48 approaches the non-contact switch 55 . The magnet 48 and the non-contact switch may be omitted.
Reference numeral 56 denotes a check valve, and an enlarged view thereof is shown in FIG. 1 ( b ). Namely, a hole 41 b is formed at a left side of the cylinder wall 41 a , and a screw 41 c is provided at a right side of the cylinder wall 41 a . Then, a thin plate spring 57 is held by a valve seat nut 58 .
A ball 59 is inserted between a conical hole 58 a of the valve seat nut 58 with a cross-shaped hole and the thin plate spring 57 , and the ball 59 is always slightly pressed by the plate spring 57 to close the conical hole 58 a.
Reference numeral 60 is an air reservoir cover, which is screwed into the cylinder 41 to form an air reservoir 61 between the cylinder wall 41 a and the air reservoir cover. In the air reservoir 61 , by rotating the air reservoir cover 60 , a capacity of the air reservoir 61 can be changed.
Reference numeral 62 is a double nut for fixing the position of the air reservoir cover 60 . Reference numerals 63 a , 63 b , 63 c , 63 d , 63 e , 63 f and 63 g denote O-rings, which are attached to maintain airtightness.
In explaining FIGS. 4 ( a ) through 4 ( c ), FIG. 4 ( a ) is a side view of a part of the piston 46 seen from a section taken along line 4 ( a )— 4 ( a ) in FIG. 1 ( a ), and FIG. 4 ( b ) is a cross sectional view taken along line 4 ( b )— 4 ( b ) in FIG. 4 ( a ). Holes 46 a and 46 b are bored in the piston 46 , and an operation shaft 73 , wherein a compression coil spring 71 and an O-ring 72 are fitted, is stored in the hole 46 and fastened by a nut 74 to thereby form a first valve 70 .
Further, a hole 46 c , a conical hole 46 d , and a hole 46 f are bored in the piston 46 , and a ball 75 and a compression coil spring 76 are stored in the conical hole 46 d and fastened by a nut 77 , to thereby form a second valve 78 .
Next, operations of the shock absorber of the first embodiment will be explained. In FIG. 1 ( a ), the moving member W is moved rightward, and the piston 44 pressed by the moving member W slides in the piston bearing 43 to be displaced rightward. Then, as shown in FIG. 2, the piston 46 integral with the piston shaft 44 compresses air in the cylinder 41 .
Air compressed by the right end side (pushing side) of the piston 46 passes through the throttle formed by the cone portion 52 a at the left distal end of the flow quantity control shaft 52 and the hole 50 a at the left distal end of the flow quantity control bearing 50 , and air enters the air reservoir 61 from the air hole 50 b as the bypass (refer to the arrow in FIG. 2 ).
In this case, since a space between the left end side (pulling side) of the piston 46 and the cylinder head 42 is in a vacuum state, the force of absorbing the shock is increased. Further, when the piston 46 is displaced rightward, the vacuum state between the left end side (pulling side) of the piston 46 and the cylinder head 42 is further intensified, to thereby apply brake on the moving member W. Accordingly, the piston 46 gradually approaches the cylinder wall 41 a , and the operation shaft 73 shown in FIG. 4 ( b ) abuts against the cylinder wall 41 a to slide inside the piston 46 , so that the first valve 70 is opened as shown in FIG. 4 ( c ). Accordingly, air compressed by the right end side (pushing side) of the piston 46 flows into the space between the left end side (pulling side) of the piston 46 and the cylinder head 42 , which is in the vacuum state, to thereby prevent the brake effect from being excessive, so that a soft contact can be carried out.
When the ring magnet 48 of the piston 46 approaches the non-contact switch 55 , the switch 55 outputs the abutment or contact signal to send the contact signal to an outer control device through the lead 55 a.
After the contact of the piston 46 , when the moving member W is returned to the position shown in FIG. 1 ( a ), the piston 46 starts to restore (FIG. 3 ), and the ball 59 of the check valve 56 is displaced leftward to push the thin plate spring 57 to the left, so that the check valve 56 is opened. Accordingly, a large quantity of air is sent in a short time from the air reservoir 61 into the cylinder 41 , so as to accelerate the returning time of the piston 46 .
Needless to say, air in the air reservoir 61 flowing from the air hole 50 b of the bypass passes also through the throttle formed by the cone portion 52 a at the left distal end of the flow quantity control shaft 52 and the hole 50 a at the left distal end of the flow quantity control bearing 50 , and flows into the cylinder 41 .
As described above, the first valve 70 of the piston 46 is opened, and air compressed by the right end side (pushing side) of the piston 46 flows into the space, which is in the vacuum state, between the left end side of the piston 46 and the cylinder head 42 , to thereby ease the vacuum state. Thus, air is introduced into the space between the left end side (pulling side) of the piston 46 and the cylinder head 42 , so that the second valve 78 of the piston 46 is naturally opened at the time of restoring the piston 46 . In case that the piston 46 is restored to the state shown in FIG. 1 ( a ), there is no air between the piston 46 and the cylinder head 42 .
FIG. 5 is a front sectional view of a shock absorber according to a second embodiment of the invention. As compared with the shock absorber of the first embodiment in which the air reservoir 61 is provided inside the air reservoir cover 60 , the shock absorber of the second embodiment is provided with an air passage 84 , which is communicated with an outside of the shock absorber and the cylinder chamber through the air hole 50 b as the bypass, and an air joint portion 85 is attached to an outlet of the air passage 84 projecting outside the shock absorber. A chamber 86 whose capacity is adjustable is provided to the outside of the shock absorber, to thereby form an external air reservoir 87 .
Namely, the external air reservoir 87 is detachably attached to the air passage 84 by a tube 89 , and includes a control screw 91 to adjust a capacity of the air reservoir 87 . Since the capacity of the reservoir 87 is adjustable by a controlling screw 90 , the shock absorbing ability when the piston is being moved can be adjusted.
Also, other than the aforementioned method of controlling the capacity of the air reservoir, there can be used a method of replacing the chamber with another chamber of a fixed quantity having a different inner diameter and length. Further, without using the chamber 86 , the air joint portion 85 can be opened to the atmosphere, to thereby reduce the force of absorbing the shock. Also, the shock absorber can be connected to a compressed air source, not shown, to thereby increase the force of absorbing the shock.
FIG. 6 shows a front, partly sectional view of a shock absorber of a third embodiment of the invention. In the shock absorber of the first embodiment, the flow quantity control shaft 52 and the check valve 56 are used, but a speed controller, which is available in the market, has functions corresponding to the flow quantity control shaft 52 and the check valve 56 . Thus, in the shock absorber of the third embodiment, instead of the flow quantity control shaft 52 and the check valve 56 , a speed controller 91 is attached to the cylinder wall 41 a , to thereby achieve the object of the invention.
The speed controller 91 includes therein an air hole corresponding to the air hole 50 b in the first embodiment at one side of a casing of the speed controller 91 . An air chamber 92 is directly joined to a path communicating with the air hole from the speed controller. The air chamber 92 is formed similar to the second embodiment. Accordingly, the third embodiment operates as in the first embodiment.
FIG. 10 shows a front, partly sectional view of a shock absorber 93 of a fourth embodiment of the invention. In the shock absorber of the first embodiment, the flow quantity control bearing 50 is fixed to the cylinder wall 41 a to adjust the flow quantity from the compression side of the cylinder to the air chamber 61 . However, in the fourth embodiment, a throttle hole 94 is simply formed in the cylinder wall 41 a . Since the cover 60 for the air chamber 61 can be adjusted relative to the cylinder 41 , shock absorbing ability of the shock absorber 93 can be adjusted. The shock absorber 93 operates as in the first embodiment.
According to the first to fourth embodiments (FIG. 1 ( a ) to FIG. 6 and FIG. 10) of the invention, the shock absorbers employ an air system while the conventional shock absorber employs an oil system. Since air used in the shock absorber is not given to or received from the outside at all, air can be airtightly confined in the shock absorber. Thus, the shock absorbers of the embodiments are excellent in dustproof and oilproof functions, and can be used in a clean room.
There was a case that the force of absorbing the shock in the conventional shock absorber using air is deficient in order to absorb the movement of the detecting member as compared with the conventional oil-type shock absorber. However, in the shock absorber according to the present invention, since the suction force of the piston due to the vacuum state caused between the pulling side of the piston and the cylinder is added to the resistance force of air compressed by the pushing side of the piston and the cylinder, the absorbing force which is sufficient for absorbing the movement of the detecting member can be obtained.
Also, in the shock absorber according to the present invention, a degree of absorbing the shock can be controlled by a method of varying both the flow quantity controlling valve and the capacity of the air chamber, or by a method of varying either of them. Accordingly, the shock absorber, in which both the flow quantity controlling valve and the capacity of the air chamber are controllable, can be used widely, and the shock absorber in which either of the above is controllable can be used for an exclusive purpose, so that it can be very handy in some cases.
While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.
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In an air-type shock absorber, a piston is sealing situated in a cylinder chamber. A vacuum state occurs in a piston bearing side of the cylinder chamber when a piston is pushed. Also, an air reservoir is provided at a side opposite to the piston bearing to have a sealed structure, so that a force of absorbing a shock can be increased to have the same effect as in an oil-type shock absorber. The shock absorber can be used not only at a place requiring cleanness but also in adverse environment in which the shock absorber is exposed to water or coolant, and durability of the shock absorber is also improved.
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FIELD OF THE INVENTION
[0001] The present invention relates to a horizontal balanced concave fishing lure with both ends similarly shaped (symmetrical) as in a willow leaf spinner blade and more particularly to a lure that is connected at its horizontal balanced or mid point, creating a more lifelike appearance and action.
BACKGROUND OF THE INVENTION
[0002] The last dozen or so years have seen a huge increase in vertical jigging methods. This includes several techniques designed for vertical presentation such as drop shoting which will be explained in full in the Detailed Description section. Probably the most pronounced use of new jigging techniques is in the sport of ice fishing throughout the Northern Hemisphere. This, of course, is mainly limited to vertical presentations of bait and or lures . . . or a combination of the two.
[0003] The vertical manipulation methods (other than drop shoting) are often done with existing lures which were designed for standard casting and/or trolling techniques. Although they can be successful, it is generally in spite of the design and function rather than because of it, and this has limited unnecessarily, the success of the angler.
[0004] One solution is a small group of Jigging lures by Normark/Rapala led by the. “Jigging Rap” which were specifically designed to rest in a horizontal position. It can be worked up and down by jigging the rod tip in various ways. Some horizontal side movement can be achieved.
[0005] Another lure that has been effective for many decades is the Swedish Pimple by Bay-de-Noc Fishing products company of Gladstone Mich. It often sells the Swedish Pimple lure with a tear dropped shaped attractor attached which greatly aids the presentation when jigged vertically. They also promote the placement of bait on the hooks such as perch eyes, small section of worm or maggots and other real baits which have both natural scent and some movement with very little motion to the rod tip.
[0006] A third group of lures that often rest horizontally are weighted jigs. They can be fished vertically, but more often are used as casting lures which is benefited by fact that the size of the jig head can vary and the increased weight ads to the distance the lure can be cast and/or how quickly it will descend.
[0007] Another group of more recent lures are very small jig style lures specifically designed for ice fishing for “panfish”.
[0008] No other lures of which I am aware use the center balance point beyond the Normark/Rapala
[0009] In the case of the Normark/Rapala Jigging Rap it is very expensive to manufacture and therefore equally expensive to purchase by the angler. Although it has good visual appeal to the fish, it is distracted by large hooks protruding out both of the horizontal ends. Its success is really the result of the unique but effective horizontal position of the lure itself and the ability to make it dart in one direction or anther by skilled manipulation by the angler.
[0010] The Swedish Pimple is aided by the tear drop shaped attractor which is often attached and their suggestion (in the marketing materials) that live or real bait be added. The fact remains that the lure rests in a vertical position, which is unnatural for a minnow imitation to suspend in a vertical mode.
[0011] It is very surprising that no other concepts have evolved which attach at the center of the lure except inventions being offered by this inventor. One of the author's inventions is a bar shaped lure with equal sections on both ends. But this inventor will readily admit that one shortcoming of this lure is it also suspends in a vertical position when not being worked or jigged.
[0012] The ice jigging lures are sometimes well balance horizontally, but seldom resemble a minnow and are more often are tipped with actual bait such as maggots, meal worms, or a small piece of worm, and are generally designed to imitate insect larva. There is usually little weight involved so the use is mainly lowering vertically through a hole in the ice and it's success is usually limited to panfish.
SUMMARY OF THE INVENTION
[0013] In accordance with the present invention, there is provided a concave bodied lure with equal ends and a jig hook which extends through the center of the body causing the lure to suspend in a horizontal position when at rest and produce a variety of attractive movements when the rod is twitched, or more aggressively jigged up and down.
[0014] It would be advantageous to provide a fishing lure that is connected to the line at the horizontal balance point.
[0015] It would also be advantageous to provide a lure to which the hook portion can be secured in a groove or channel from the center hole of the body extending to the rear allowing the hook to be glued, braised, or soldered in a secure position.
[0016] It would further be advantageous to provide a vertical extension of the jig hook which provides both the center balance point connection and the ability to attach a split shot of various sizes to change the weight and therefore the action and fishing characteristics of the lure.
[0017] It would be a further advantage to provide a method to attach various enticements to the rear portion either in the form of bait, physical attractor, or both.
[0018] It would further be advantageous to provide for different shapes of concave symmetrical lure bodies with the midpoint balance position connection to the fishing line.
[0019] It would also be advantageous to provide a jig hook with a molded round weight (painted or with decal) to resemble an eye of a bait fish) attached.
[0020] It would further be advantageous to have the alternate attachment at the front of the lure for most casting applications
[0021] It would be most advantageous to have small lure sizes and little or no attached weight and a front connection for fly rod presentations. which normally use the weight of the line not the lure) for casting.
[0022] Another advantage is to provide a flat horizontally balanced symmetrical fishing lure variation.
[0023] Also advantageous would be to provide a fishing lure balanced centrally and symmetrically that is convex.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:
[0025] FIG. 1 is a side view of a horizontal willow leaf blade lure;
[0026] FIG. 2 is a top view of a horizontally balanced center hole fishing lure;
[0027] FIG. 3 is a bottom view of a willow leaf balanced lure illustrating the jig hook channel for connection of the jig hook to the lure body;
[0028] FIG. 4 is a cross section view of a willow leaf shaped horizontal fishing lure illustrating its mid or balance point;
[0029] FIG. 5 is a side view of a jig hook with mold weight;
[0030] FIG. 6 is a side view of a flat horizontally balanced fishing lure; and
[0031] FIG. 7 is a side view of a convex horizontally balanced fishing lure.
[0032] For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the Figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] FIG. 1 is a side view of a horizontally balanced fishing lure. Although willow leaf blades are widely used in fishing lures it has been limited to use as a spinning blade. That spinning blade is connected to a spindle at the end point with the purpose of “spinning” around this spindle or shaft, thereby creating vibration and attracting various species of fish. This adaptation of a spinner blade and existing jig hook 16 creates an entirely new category of lures by connecting a spinner blade like concave lure body to the fishing line at it's mid point, or balanced position. Therefore the blade rests in a horizontal position with the concave side down, presenting a much more natural appearance such as a minnow or other bait fish assumes while resting.
[0034] Because of the lure's boat like shape it will slide from side to side and front to back as it is allowed to settle through the water column, thereby resembling a wounded bait fish in both appearance and behavior. This is created by the concave shape of the blade and its connection at the center hole 12 or mid point. When the lure is raised, the water must find its way out of the “boat” thus creating a pressure release which emulates the sound of a bait fish to predator fish. This balance point is further affected by the addition of an attractor 38 to the bend of the hook or some form of bait to the rear portion of the hook.
[0035] This figure shows how an attractor 38 , such as the clip on attractors filed by this inventor, can be clipped to jig hook bend 46 or curved portion of the hook giving it very enticing action when merely twitched very lightly.
[0036] A very important use of the this lure (without weight on the jig hook 16 ) is for fly fishing. Because the weight is very slight it allows fly fishermen (using the principal of the weight of the line essentially casting the fly or lure) to project the fly. This lure can be easily cast and worked with fly fishing gear, opening up a totally new undiscovered adaption.
[0037] FIG. 2 is a top view of a willow leaf shaped lure. looking down on the willow leaf shaped body 10 or blade, further illustrating the midpoint or balance point. There is a center hole 12 near the mid-point of the blade just slightly forward of the middle. This slightly forward placement is because the jig hook 16 terminal portion extends slightly beyond the rear end of the blade and this location allows the lure to rest in a horizontal position. Also when bait or an attractor 38 is added to the hook, it will affect the balance point slightly depending on the weight of the added element.
[0038] The jig hook stem 32 protrudes up through the center hole 12 and is terminated with the jig hook eye 36 , which is the main attachment point. This is key to the action that is produced when the lure is fished using an up and down jigging motion or slight twitching action. The small center hole 12 allows the jig hook barb 44 to be inserted through the center hole 12 to thread the jig hook 16 through the willow leaf shaped body 10 and in position for solder, glue or weld connection. This view also shows the location of the jig hook channel 28 which extends from the center hole 12 to the rear portion of the willow leaf shaped body 10 . This is further illustrated in FIG. 3 below.
[0039] FIG. 3 is a bottom view of a willow leaf shaped body 10 showing the placement and connection to the body of a jig hook 16 . Jig hooks have been previously used with a mold generally filled with lead or more environmentally friendly metals. often with some form of attraction material such as buck tail or Millar etc. to resemble a minnow at rest. It is so widely used and effective because the jig hook 16 is held at a horizontal position and when “worked” by the angler it looks and acts like a minnow trying to escape or is injured in some way.
[0040] That is precisely why this new form of horizontally suspended lure is both highly effective and inexpensive to construct. Other forms of elaborate lures, such as the Normark/Rapala's “Jigging Rap” and “Ripping Rap”, are proven to be effective for species such as walleyes and northern pike and owe their success mainly to the fact that they are attached at the balance point as well. However, they are very expensive to produce and therefore equally expensive for the angler to purchase. In addition, they are not nearly as effective for panfish and trout that normally feed on smaller quarry.
[0041] In this illustration it shows how the jig hook shank 34 rests in the jig hook channel 28 allowing this portion of the hook to solidify the jig hook 16 by using solder, weld, or glue to surround the jig hook shank 34 and rigidly connect the hook to the willow leaf shaped body 10 .
[0042] FIG. 4 is a cross section view of a willow leaf shaped horizontal fishing lure illustrating its mid or balance point. This figure not only shows how the jig hook 16 rests in the jig hook channel 28 , but also how the connection stem extends vertically to the attachment eye. This further illustrates how the angler can add weight to the stem in the form of various sizes of split shot 24 . The type of split shot 24 preferred would be the type that has flaps for easy removable if the weight is preferred to be changed or removed. This can be important for fishing in relatively deep water as the rate of decent is a significant factor, as is the ability to cast. Although mainly designed as a vertical jigging lure it can be cast and fished much as any jig with a metal head making this more versatile than almost any type of artificial lure. This is achieved by using the option to attach the line (using a terminal snap and swivel) to the front connection hole 26 . It has further versatility and attraction when attaching to the center hole 12 , and with or without a split shot 24 , and used in a more conventional manner by casting or trolling the lure. Here the concave nature of the willow leaf shaped body 10 creates resistance which translates to vibration and other sounds audible and attractive to fish. Furthermore, when the lure is allowed to settle, the erratic slip-sliding action will resume, whichever attachment point is used.
[0043] It is anticipated that this design will become the centerpiece of an entirely new group of lures which attach at the center or balance point and have a wide variety of highly attractive movements That is why the inventor should be given a reasonably wide degree of associated claims so that his novel idea can be further augmented by future patents under his name.
[0044] FIG. 5 shows a side view of typically molded jig hook 16 with the intended amount of weight already attached to the jig hook shank 34 . Often the lead or titanium placed in the mold will cover both the jig hook stem 32 and a small portion of the jig hook shank 34 . In the case of the horizontally balance fishing lure the jig hook stem 32 may be extended somewhat to allow the mold portion to only cover the jig hook stem 32 , depending on the size of the oval weight desired.
[0045] The advantage of the precast jig hook 16 (with molded eye weight 42 already attached) is that it is somewhat simpler to solder, glue, or weld the jig hook 16 to the willow leaf shaped body 10 . with more rigidity. It also allows for the weight portion to be colored to resemble a bait fish eye, which will be attractive to almost all gamefish. Furthermore it simplifies the process for the angler, in that a split shot 24 will not need to be attached as a separate step. It is suspected that most anglers will find a particular weight of lure most advantageous for each different application and targeted species of game fish.
[0046] This figure also further illustrates the function of the jig hook barb 44 to prevent a clip-on attractor 38 from slipping off the shank of the hook. The diameter of connecting hole will be slightly larger than the jig hook shank 34 to allow freedom of motion, but not so large as to allow the attractor 38 to slide by the combined diameter of the shank and the jig hook barb 44 .
[0047] What makes this lure so efficient (in terms of production costs), is both the willow leaf shaped body 10 and the jig hook 16 , without weight and with molded weight are produced in large numbers for a long time making the cost of these elements very competitive. The fact that the function of these two elements (connected and used in the previously described ways) makes the lure produce unusual and effective motions and sounds.
[0048] FIG. 6 is where it gets even more interesting. Although originally designed to have a concave shape, further experimentation and testing showed and entirely unique set of movement when a flat symmetrical shaped body 48 is used. The direction it takes when lowered or raised (due to the horizontally balance connection) is very detailed and deceptive. This give the angler ultimate control over the lure's action, especially in vertically suspended situations like ice fishing, or vertical jigging. A slight twitch may slide the lure in any direction and a foot of upward movement can create any one of a number of vibrations or sound effects detectable by fish. Because there is so much variety achievable in both sight movement and sound, this is an important variation of the basic concave design.
[0049] The flat design also makes the attachment of the jig hook 16 more solid with solder, weld or gluing techniques.
[0050] FIG. 7 illustrates yet another behavioral effect for this horizontally balance symmetrical lure design, when a convex symmetrical shaped body. is used. Here the upward effect can be more dramatic visually, but with less sound and vibration. Conversely, as it is allowed to settle through the water column, more side movement and variations will occur. For the serious fisherman, this will open a new arena of lure manipulation and thus reaction from game fish. Sizes and symmetrical shape variations are endless and offering the angler actions and reactions not possible with the other major types of fishing lures, namely: plugs, spoons, spinners, jigs, and fly's.
[0051] This design will make the hook-to-body attachment easier since the convex design also creates a channel for the hook shank to rest.
[0052] Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
[0053] Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.
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A concave, flat, or convex metal, plastic, or composite bodied lure with somewhat pointed and similar ends and a jig hook which extends through the center of the body and is connected in a channel that proceeds to the rear, causing the lure to suspend in a horizontal position and produce a variety of attractive movements when the rod is jigged vertically or otherwise manipulated.
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BACKGROUND OF THE INVENTION
The present invention relates to a magnetic recording medium, and more particularly, to a magnetic recording medium which is used in the high-density records such as digital audio-tape, high picture-quality video tape, high-density floppy disc, etc., and is better in lubricating characteristics and superior in durability.
Conventionally, the coating material composed of magnetic powder, binder resin, organic solvent and other necessary components is applied on a base body such as polyester film or the like to produce a magnetic recording medium. In the practical use, the magnetic layer is likely to be worn away because of hard sliding with the magnetic head, the pad, etc. Thus, superior lubricating property on the surface, less wear property of the magnetic layer, and high durability are desired.
In order to improve the durability of the magnetic recording medium, various lubricating agents are mixed with the magnetic layer or are coated on it. Generally, liquid paraffin, high-class fatty acids and, ester of the high-class fatty acids, etc. are used as these lubricating agents.
For example, U.S. Pat. No. 654,258 discloses magnetic recording medium including fatty-acid ester and fatty-acid amide as the lubricating agent. U.S. Pat. No. 4,595,640 discloses a lubricating agent system composed of carboxylic-acid isomer and fatty-acid ester to provide a video tape which is longer in the service life of still picture operation. Also, U.S. Pat. No. 4,647,502 discloses that the ester of unsaturated high-class fatty acid and alcohol of 6 through 16 in the number of carbons is preferred as the lubricating agent in the case of the magnetic disc. Also, for example, U.S. Pat. No. 4,650,720 uses oleic acid as such a lubricating agent.
However, these conventional lubricating agents improve the durability of the magnetic recording medium, but were not sufficient in characteristics. Also, it was difficult to provide superior lubricating characteristics over a wide temperature range.
SUMMARY OF THE INVENTION
Accordingly, an essential object of the present invention is to provide a magnetic recording medium which is better in the lubricating characteristics of the magnetic layer, and is superior in the durability.
Another object of the present invention is to provide a magnetic recording medium which is better in the abrasion resisting property of the magnetic layer and superior in the durability in a wide temperature range.
Still another object of the present invention is to provide a magnetic recording medium which is superior in the durability and abrasion resistance by the use of a new lubricating-agent system composed of the combination of oleic acid and ester.
In accomplishing these and other objects, according to the present invention, there is provided a magnetic recording medium, which has on the support body a magnetic layer containing oleic acid, a first ester selected from ethyl stearate and ethyl oleate, and second ester selected from isocetyl stearate, 2-ethyl hexyl stearate and 2-ethyl hexyl laurate. The above-described construction has an effect of being better in the abrasion resistance thereof over a wide temperature range.
DETAILED DESCRIPTION OF THE INVENTION
Oleic acid used in the present invention is unsaturated fatty acid in liquid state at the room temperature of 18 in the number of carbons, and is superior in lubricating function. Especially, when the magnetic layer is in sliding contact against a magnetic head, the superior lubricating function is sufficiently exhibited to improve the durability of the magnetic layer. Also, when ethyl stearate or ethyl oleate and isocetyl stearate, 2-ethyl hexyl laurate or 2-ethyl hexyl stearate are jointly used, the lubricating functions of the above-described three materials multiplicatively work to further improve the lubricating characteristics and abrasion resistance of the magnetic layer.
The ethyl stearate or ethyl oleate is the first ester jointly used with oleic acid in the present invention. It is ester which is provided by the ethyl alcohol of 2 in the number of carbons, and the stearic acid of 18 in the number of carbons of the oleic acid. The ester has a lubricating function stable over a wide temperature range. On the other hand, the isocetyl stearate, which is the second ester, is ester provided by the isocetyl alcohol of 16 in the number of carbons and the stearic acid of 18 in the number of carbons. The 2-ethyl hexyl laurate is ester provided by the 2-ethyl hexyl alcohol of 8 in the number of carbons and the lauric acid of 12 in the number of carbons. Also, the 2-ethyl hexyl stearate is the ester provided by the 2-ethyl hexyl alcohol of 8 in the number of carbons and the stearic acid of 18 in the number of carbons. They are superior in the lubricating effect at low temperatures. They work multiplicatively, when they are jointly used with oleic acid, to further improve the abrasion-resistance of the magnetic layer, so that the lubricating characteristics and abrasion resisting property are sufficiently improved at the wide temperature range.
The compounding ratio of the oleic acid and the total ester, i.e., the total amount of the first ester and the second ester, is desirable to stay from 1:2 to 1:8 ratio in range by weight. When the lubricating agents jointly used are respectively less than the compounding ratio, the abrasion resisting property of the magnetic layer is not sufficiently improved. Especially, when the compounding ratio of the ester amount is less, the abrasion resisting property at a high temperature is not improved.
Also, when the compounding ratio of the oleic acid is more, the friction coefficient against the pad becomes higher to make the running operation unstable. When the compounding ratio of the ester is more, it bleeds out onto the surfaces of the magnetic layer to spoil the head, thus resulting in lowering the output and abrasion-resisting property through the pad.
The using amount of the first ester, the second ester and the oleic acid blended at such compounding ratio as described hereinabove is desirable to stay within 5 through 10% in total weight with respect to the magnetic powder. When it is less, the expected effect is not provided. When it is more, it bleeds out onto the surface of the magnetic layer to spoil the magnetic head, thus resulting in lowering the output.
In order to contain the oleic acid and the first and second esters in the magnetic layer, it is necessary to dissolve them into proper solvent such as normal hexane or the like and to apply or spray the solution, provided by the resolution, on the magnetic layer formed in advance or to dip the magnetic layer in the solution or to mix them with the magnetic powder and binder resin to form the magnetic layer.
The present invention will be described hereinafter in conjunction with the preferred embodiments thereof.
EMBODIMENT 1
______________________________________oleic acid 2 parts by weightmagnetic powder 250 parts by weightVAGH (vinyl chloride acetate- 82 parts by weightvinyl alcohol copolymer,manufactured by UCC Company,USA)N-2304 (polyurethane, manufac- 18 parts by weighttured by Nippon PolyurethaneIndustry)Coronate L (polyisocynate, 7.5 parts by weightmanufactured by NipponPolyurethane Industry)granular aluminum 12.5 parts by weightcarbon black 15 parts by weightmethyl ethyl ketone 500 parts by weighttoluene 500 parts by weight______________________________________
The composition is mixed, dispersed in a ball mill to adjust the magnetic coating material. The magnetic coating material is applied iupon both faces of the polyester film of 75 microns in thickness so that the dry thickness may become 2 microns and is after-dried to form the magnetic layer. Then, it is dipped for a short time in an impregnation solution having composition ratios shown in Table 1 below. After the drying operation, it is stamped out into a disc shape to provide magnetic discs.
TABLE 1______________________________________Impregnation Solution CompositionSamples Ethyl Stearate Isocetyl Stearate n-hexane______________________________________A 8 parts 2 parts 100 partsB 4 parts 4 parts 100 partsC 3 parts 8 parts 100 partsD 2 parts 7 parts 100 partsE 2 parts 8 parts 100 parts______________________________________
EMBODIMENT 2
The oleic acid, the ethyl stearate and the isocetyl stearate in ratio of 1:1:3.5 by weight and in total weight of 8% to the magnetic powder, are mixed with the magnetic powder and the binder resin to produce the magnetic coating material. The magnetic disc is produced in the same manner as that of embodiment 1, except for the dipping operation in the impregnation solution, with the thus obtained coating material.
EMBODIMENT 3
In the impregnation solution composition of embodiment 1, ethyl oleate, instead of ethyl stearate, is used as the first ester, and 2-ethyl hexyl laurate, instead of the isocetyl stearate of the second ester, is used. The magnetic disc is produced, with the composition ratio and the process for producing the magnetic coating-material being the same as that of embodiment 1.
EMBODIMENT 4
The ratio of the oleic acid, the ethyl oleate and 2-ethyl hexyl laurate in ratio of 1:1:3.5 by weight and in the total weight of 8% to the magnetic powder, are mixed with the magnetic powder and the binder resin to produce the magnetic coating material. The magnetic disc is produced in the same manner as that of embodiment 1 except for the dipping operation in the impregnation solution.
EMBODIMENT 5
In the impregnation solution composition of embodiment 1, the ethyl stearate was used likewise as the first ester, and the 2-ethyl hexyl stearate, instead of isocetyl stearate, is used as the second ester. Then, the magnetic disc is produced in the same manner as that of embodiment 1.
EMBODIMENT 6
The ratio of the oleic acid, the ethyl stearate and the 2-ethyl hexyl stearate in ratio of 1:1:3.5 by weight and in the total weight of 8% to the magnetic material, are mixed with the magnetic powder and the binder resin to produce the magnetic coating material. The magnetic disc is produced in the same manner as that of embodiment 1 except for the dipping operation in the impregnation solution.
COMPARISON EMBODIMENT 1
In the blended composition of the fatty acid and the esters in embodiment 2, the oleic acid is changed into lecithin, ethyl stearate is changed into n-butyl stearate, and the isocetyl stearate is changed into dioleyl adipate, equivalently, respectively. Then, the magnetic disc is produced in the same manner as that of embodiment 2.
In order to check the durability, at the room temperature and high and low temperatures, about the magnetic disc provided in each embodiment and each comparison embodiment, each magnetic disc is inserted into a jacket for spoil-preventing use, and is filled into the record reproducing apparatus. Then, the running time while the reproduction output becomes 80% of the initial output is measured, at the contact of the magnetic head and the disc with the pad pressure of 25 g/cm 2 under each of the conditions of 0° C. through 50° C. Table 2 shows the results thereof.
TABLE 2______________________________________ Running time Running Running time (hour) at room time (hour)Samples (hour) at 0° C. temperature at 50° C.______________________________________Embodiment 1 A 245 237 187Embodiment 1 B 377 357 286Embodiment 1 C 432 398 415Embodiment 1 D 498 476 457Embodiment 1 E 376 352 318Embodiment 2 492 413 425Embodiment 3 A 226 219 172Embodiment 3 B 348 329 264Embodiment 3 C 398 367 382Embodiment 3 D 459 438 421Embodiment 3 E 347 324 293Embodiment 4 453 380 392Embodiment 5 A 235 228 179Embodiment 5 B 362 343 275Embodiment 5 C 415 382 398Embodiment 5 D 478 457 439Embodiment 5 E 361 338 305Embodiment 6 472 396 408Comparison 138 198 108Embodiment 1______________________________________
EMBODIMENT 7
The magnetic layer formed in embodiment 1 is dipped for a short time in the impregnation solution having the composition ratio shown in Table 3 below. After the drying operation, it is stamped out into disc shape to provide the magnetic disc.
TABLE 3______________________________________ Impregnation Solution CompositionSamples Ethyl Oleate Isocetyl Stearate n-hexane______________________________________A 8 parts 2 parts 100 partsB 4 parts 4 parts 100 partsC 3 parts 8 parts 100 partsD 2 parts 7 parts 100 partsE 2 parts 8 parts 100 parts______________________________________
EMBODIMENT 8
The ratio of the oleic acid, the ethyl oleate and the isocetyl stearate in ratio of 1:1:3.5 by weight and in the total weight of 8% to the magnetic powder, are mixed with the magnetic powder and the binder resin to produce the magnetic coating material. The magnetic disc is produced in the same manner as that of embodiment 1 except for the dipping operation in the impregnation solution.
EMBODIMENT 9
The magnetic layer formed in embodiment 1 is dipped for a short time in the impregnation solution having the composition ratio shown in Table 4 below. After the drying operation, it is stamped out into disc shape to provide the magnetic disc.
TABLE 4______________________________________Impregnation Solution CompositionSamples Ethyl Stearate 2-Ethyl hexyl laurate n-hexane______________________________________A 8 parts 2 parts 100 partsB 4 parts 4 parts 100 partsC 3 parts 8 parts 100 partsD 2 parts 7 parts 100 partsE 2 parts 8 parts 100 parts______________________________________
EMBODIMENT 10
The ratio of oleic acid, ethyl stearate and 2-ethyl hexyl laurate in ratio of 1:1:3.5 by weight and in the total weight of 8% to the magnetic powder, are mixed with the magnetic powder and the binder to produce the magnetic coating material. The magnetic disc is produced in the same manner as that of embodiment 1 except for the dipping operation in the impregnation solution.
EMBODIMENT 11
The magnetic layer formed in embodiment 1 is dipped for a short time in the impregnation solution having the composition ratio shown in Table 5 below. After the drying operation, it is stamped out into disc shape to provide the magnetic disc.
TABLE 5______________________________________Impregnation Solution CompositionSamples Ethyl Oleate 2-Ethyl hexyl Stearate n-Hexane______________________________________A 8 parts 2 parts 100 partsB 4 parts 4 parts 100 partsC 3 parts 8 parts 100 partsD 2 parts 7 parts 100 partsE 2 parts 8 parts 100 parts______________________________________
EMBODIMENT 12
The ratio of oleic acid, ethyl stearate and 2-ethyl hexyl stearate in ratio of 1:1:3.5 by weight and in the total weight of 8% to the magnetic powder, are mixed with the magnetic powder and the binder resin to produce the magnetic coating material. The magnetic disc is produced in the same manner as that of embodiment 1 except for the dipping operation in the impregnation solution.
COMPARISON EMBODIMENT 2
In the blended composition of the fatty acid and the esters in embodiment 8, the oleic acid is changed into lecithin, ethyl oleate is changed into n-butyl stearate, and isocetyl stearate is changed into dioleyl adipate equivalently, respectively. Then, the magnetic disc is produced in the same method as that of embodiment 8.
Even in the magnetic disc provided in the abovedescribed embodiments and comparison embodiments, each magnetic disc is likewise inserted into a jacket for spoil preventing use, and is filled into the record reproducing apparatus to measure the running time while the reproduction output becomes 80% of the initial output, at the contact of the magnetic head and the disc with the pad pressure of 25 g/cm 2 under each of the conditions of 0° C. through 50° C. Table 6 shows the results thereof.
TABLE 6______________________________________ Running time Running Running time (hour) at room time (hour)Samples (hour) at 0° C. temperature at 50° C.______________________________________Embodiment 7 A 267 261 206Embodiment 7 B 414 393 315Embodiment 7 C 475 438 456Embodiment 7 D 548 526 503Embodiment 7 E 413 387 349Embodiment 8 541 454 467Embodiment 9 A 244 237 186Embodiment 9 B 376 357 286Embodiment 9 C 432 397 414Embodiment 9 D 497 475 457Embodiment 9 E 375 352 317Embodiment 10 491 412 423Embodiment 11 A 235 228 179Embodiment 11 B 362 343 275Embodiment 11 C 415 382 398Embodiment 11 D 478 457 439Embodiment 11 E 361 338 305Embodiment 12 472 396 408Comparison 138 198 108Embodiment 2______________________________________
As is clear from the foregoing description, according to the present invention, the magnetic discs provided in the embodiments are longer in the running time at 0° C. through 50° C. as compared with the magnetic discs provided in the comparison embodiments.
As described hereinabove, according to the present invention, the magnetic recording mediums are provided which are superior in abrasion resistance property of the magnetic layer and superior in durability in the wide temperature range. In the above-described embodiment 1, the composition with oleic acid being blended from the beginning is dispersed in the ball mill to improve the dispersion effect. For example, in the so-called high viscosity dispersion by a planetary mixer, the coating material is produced without the oleic acid, and the oleic acid is contained in the impregnation solution, so that the same effect may be provided.
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A magnetic recording medium characterized in that a magnetic layer composed of the combination of oleic acid and ester, whereby it is better in the lubricating characteristics of the magnetic layer and in the abrasion resisting property of the magnetic layer, and superior in the durability in a wide temperature range.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/909,773, filed Apr. 3, 2007, entitled “Device for the Continuous Coating of a Strip-Like Substrate,” which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention generally relate to a device for continuous coating of a strip-like substrate in a vacuum, especially for manufacturing coating patterns on the substrate with a printing roller and a backing roller between which the substrate is transported.
[0004] 2. Description of the Related Art
[0005] The invention furthermore relates to devices for continuous coating of a strip-like substrate in a vacuum wherein in a working position adjustable with a servo unit, the printing roller and the backing roller are in operative connection with one another by means of which a coating or release agent is transferable to the substrate via the printing roller.
[0006] Devices of this kind are used especially in coil coating installations for continuous evaporation or sputtering of foil strips and webs in a vacuum. In special embodiments, they serve for example in the production of coating patterns on the strip-like substrate that are formed either in longitudinal stripes or across the full coating width of the substrate to be coated. These coating patterns, also called pattern structures, have in some cases sections that are coating-free that can be realized by different coating masks. In pattern masking, a special oil-masking technique, when this technology is applied to coil coating technology, the coating-free sections are masked by means of a release agent, mostly oil, before the coating material is applied to the substrate. The prior art, as known from, e.g. DE 197 32 929 A1, DE 43 10 085 A1 and DE 41 00 643 C1, consists in feeding the strip-like substrate, e.g. a foil strip between a printing roller and a backing roller, with the printing roller having projecting pattern elements, which are wetted with an oil film, such that an oil pattern is applied to the strip-like substrate during roll-off of the printing roller. The oil-patterned strip is subsequently coated by sputtering or evaporation, whereby the, e.g., metallic coating material deposits on the oil-free sections of the substrate as a layer of metal and the masked areas are protected from the condensing metal, such that the result is selective metallization pattern on the substrate. Capacitor foils are made in this way, for example.
[0007] Setting of the printing roller and the backing roller relative to each other in a working position in which the release agent is transferred to the substrate occurs by means of a servo unit, which has a guideway for the printing roller or the backing roller, an adjustable stop of the guideway as well as one or more hydraulically or pneumatically actuated pressure cylinders for offsetting the rollers. When the pressure cylinders are actuated, for example, the printing roller is moved axially parallel with the backing roller toward the latter. Likewise, the backing roller can also be moved by means of the pressure cylinder toward the printing roller. The adjustable stop of the guideway limits the respective pressure cylinder stroke at an end position, which corresponds to the precise working position of the printing roller relative to the backing roller. The position of the stop is predetermined by a manual adjusting screw corresponding to the parameters of the respective pattern process. Thus, the rollers, under variable parameters, are aligned with each other with the greatest precision in the working position required in each case. The position selected for the stop is fixed with a clamping screw. Counter-pressure cylinders of the servo unit that are directed against the pressure cylinders move the printing roller from the working position into a resting position in which the printing roller and the backing roller are disconnected from each other in order that, for example, a sleeve of the printing roller may be exchanged for the projecting pattern elements. Exchangeable sleeves make it possible to produce strip-like substrates in all kinds of patterns. After a sleeve change, the working position has to be reset in order that correct alignment and the appropriate contact pressure of the printing roller against the backing roller may be ensured. To this end, the locator of the stop is released by hand and the pressure cylinder is actuated until the printing roller rests flush against the backing roller. Subsequently, the stop is adjusted by means of the adjusting screw in accordance with the executed pressure cylinder stroke and located in position with the clamping screw. The coil coating installation is then sealed vacuum-tight, evacuated and test coating is performed so that the dimensional accuracy of the coating pattern may be checked. The precision with which the working position of the rollers has been set by the servo unit can be judged only from the coated substrate. If necessary, the setting process must be repeated after venting of the coil coating installation, and more precisely until the coating pattern is of the desired quality. Precision setting of the working position of the printing roller against the backing roller after a change in parameters of the pattern process, such as after a sleeve change, therefore entails a high outlay on time, which can amount to more than one working day, depending upon the situation. In addition, this time- and labor-intensive setting-up causes substantial production downtimes, which impair the economics of the coil coating installation.
[0008] The object of the invention is therefore to overcome the disadvantages of the prior art and to improve the adjustability of the generic device. This object is achieved in accordance with patent claim 1 by the servo unit's having a controllable servo motor for adjusting the working position.
SUMMARY OF THE INVENTION
[0009] The present invention generally relates to a device for continuous coating of a strip-like substrate in a vacuum, especially for manufacturing coating patterns on the substrate with a printing roller and a backing roller between which the substrate is transported. The invention furthermore relates to devices for continuous coating of a strip-like substrate in a vacuum wherein in a working position adjustable with a servo unit, the printing roller and the backing roller are in operative connection with one another by means of which a coating or release agent is transferable to the substrate via the printing roller.
[0010] In one aspect of the invention, the device for the continuous coating of a strip-like substrate in a vacuum includes a printing roller and a backing roller, where the substrate is guided between the printing roller and the backing roller. The device also includes a coating or release agent transferable to the substrate via the printing roller. Furthermore, the device includes a servo unit that has a controllable servo motor, wherein in a working position adjustable with the servo unit, the printing roller and the backing roller are in operative connection with one another.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] So that the manner in which the above-recited features of the present invention can be understood in detail, a more particular description of embodiments of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawing. It is to be noted, however, that the appended drawing illustrates 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.
[0012] FIG. 1 is a side view of an inventive embodiment of the device, labeled pattern module, in a working position.
[0013] FIG. 2 is a side view of the pattern module in the resting position.
[0014] FIG. 3 is a cross-sectional view of a detail of the pattern module in working position.
DETAILED DESCRIPTION
[0015] Embodiments of the invention generally relate to a device for continuous coating of a strip-like substrate in a vacuum, and, more specifically, to manufacturing coating patterns on the substrate with a printing roller and a backing roller. The substrate is guided between the printing roller and the backing roller. A coating or release agent is transferable to the substrate via the printing roller when the printing roller and backing roller are in operative connection with one another. The device also includes a servo unit that has a controllable servo motor, wherein in a working position adjustable with the servo unit, the printing roller and the backing roller are in operative connection with one another. The measures specified in the dependent claims of patent claim 1 describe advantageous embodiments and arrangements of the invention.
[0016] Setting of the working position of the rollers acting in operative connection with one another does not have to be effected by manual adjustment on the servo unit itself. If, for example, the rotational position of the adjusting screw, which determines the position of the stop of the guideway of the rollers, is motor-controlled or if a controllable servo motor is used for the adjustment movement for the purpose of changing the gap between the printing roller and the backing roller, the working position can be set by controlling the servo motor(s) from the outside, i.e. outside the vacuum-tight coil coating installation. The result is that repeated evacuation and venting of the coil coating installation during the adjustment process are unnecessary, a fact which leads to enormous time savings. As a corollary, process downtimes are substantially shortened and the servo unit is easier to operate.
[0017] If the servo motor is used for the adjusting movement for setting a radial distance between the printing roller and the backing roller, it is possible, in addition to the printing roller for feeding the roller(s) into a working position, to eliminate the counter-pressure cylinder for returning the roller(s) into a resting position during a break in production, since the servo motor can equally effect the changing, counter-directional controlling movement of the printing or backing roller into the working position or into the resting position. This leads not only to minimization of servo unit design but, due to elimination of the hydraulic or compressed air connections to the pressure or counter-pressure cylinder, also to an elimination of associated line feedthroughs through the vacuum chamber wall of the coil coating installation, a fact which reduces the risk of leaks.
[0018] If a stepper motor is provided as servo motor, particularly precise graduated adjustment of the working position can take place. The stepper motor is a synchronous motor, which can be precisely rotated through a minimum angle (step) or an exact multiple of the angle by a controlled, stepped-rotating electromagnetic field. If a stepper motor is used especially for adjusting the radial distance between the printing roller and the backing roller, this distance can be altered in precise increments, and thus precise adjustment of the working position can be effected, such that a mechanical stop in the guideway of the rollers for precision adjustment can be dispensed with in the design. Since stepper motors precisely follow the applied external electromagnetic field because of their synchronous motor behavior, they can be directly controlled with high precision, without the need for an automatic control loop with sensors for position feedback.
[0019] Preferably, the printing roller can be connected to and disconnected from the backing roller by means of the servo unit. In this regard, the backing roller is permanently fixed in its axial position, with only the printing roller being adjustable, in order that the working position and the resting position may be realized. The function of the servo unit here is reduced to connection and disconnection of the printing roller, as a result of which the design effort for the servo unit is further minimized and at the same time the positioning accuracy is improved because of fewer error influences.
[0020] In a particularly advantageous embodiment, the servo unit has a guide carriage mounted on a guide rail, on which carriage the printing roller is arranged. Thus, linear guiding of the printing roller is possible, which being precisely aligned perpendicular to the axis of rotation of the backing roller, ensures axially parallel guiding of the printing roller relative to the axis of rotation of the backing roller in any position. This guide rail influences minimizes interfering influences on the axial parallelism of the rollers during the adjustment process. Precision is further increased if two guide rails, on which the guide carriage is mounted, are provided. In addition, further necessary elements of the device can be arranged on the carriage that can thus form a compact unit untroubled by the positioning movement of the rollers. These elements may be, for example, those necessary for supplying the printing roller with the release agent, such as a transfer roller in roll-off contact with the printing roller with following anilox roll, to which oil is fed from an oil evaporator.
[0021] FIGS. 1 to 3 show an embodiment of the inventive device labeled pattern module 1 , which is a component of a coil coating installation not shown in more detail. The pattern module 1 comprises a printing roller 2 and a backing roller 3 in operative connection with it, between which the strip-like substrate 4 , e.g. a plastic film 4 is transported (evident from FIGS. 1 and 3 ). The backing roller 3 is pivotably mounted about its axis of rotation 5 in a non-visible, fixed bearing and is driven by a gear wheel coupling device 6 .
[0022] The printing roller 2 is mounted by means of a roller recipient 7 on a movable guide carriage 8 , which is linearly displaceable in the traversing direction 9 . On the guide carriage 8 are arranged, among other things, also an oil evaporator (hidden), a transfer roller 10 and a anilox roll 11 , with the anilox roll 11 being in direct roll-off contact with the transfer roller 10 and this, in turn, in roll-off contact with the printing roller 2 (evident from FIGS. 1 and 2 ). Oil evaporator, anilox roll 11 and transfer roller 10 supply the printing roller 2 with oil. The printing roller has a sleeve 12 , which is wetted with the oil. Thus, in a working position in which the printing and the backing roller 2 , 3 are in operative connection with one another, that is, their surfaces roll off each other under inter-positioning of foil 4 , an oil pattern is transferable from the printing roller 2 to the substrate 4 (see FIGS. 1 and 3 ). For the purpose of transferring the oil pattern in the working position, the printing roller 2 is in mesh with the gear wheel coupling device 6 .
[0023] The guide carriage 8 is mounted on two spaced-apart guide rails 13 , with the guide rails 13 aligned such that the printing roller 2 mounted on the guide carriage 8 may be pushed relative to the backing roller 3 while maintaining a position axially parallel to the axis of rotation 5 . Guide carriage 8 and guide rails 13 are part of a servo unit 14 , which is actuated by a servo motor 15 fixed on each side of the guide rails 13 (see FIG. 3 ). The servo motors 15 act on the guide carriage 8 and shift this together with the printing roller 2 along the guide rails 13 in traversing direction 9 , such that the servo unit 14 , under the drive of the servo motors 15 , makes possible both connection of the printing roller 2 to the backing roller 3 and, in reverse operation of the servo motors 15 , disconnection of the printing roller 2 from the backing roller 3 . The servo motors 15 implemented as stepper motors 15 shift the guide carriage 8 in predetermined increments, such that any desired radial distance 16 can be adjusted between the printing roller 2 and the backing roller 3 . Thus, by means of this inventive servo unit 14 , not only a working position of the pattern module 1 in accordance with FIGS. 1 and 3 , in which the printing and backing roller 2 , 3 are in operative connection, but also a resting position is positionable, in which the printing and backing roller 2 , 3 are spaced apart from each other for a break in production of pattern module 1 ( FIG. 2 ).
[0024] The radial distance 16 between the printing roller 2 and the backing roller 3 is adjustable by means of the stepper motors 15 in very small increments, such that, as necessary, the working position of the printing and backing roller 2 , 3 in operative connection can be adjusted precisely. By means of remote control of the stepper motors 15 via a central control unit outside the coil coating installation, this adjustment can be effected on the evacuated pattern module 1 , even during the coating process.
[0025] While the foregoing is directed to embodiments of the 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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The invention relates to a device for the continuous coating of a strip-like substrate in a vacuum, especially for producing coating patterns on the substrate, with a printing roller and a backing roller, the substrate guided between the printing roller and the backing roller. The invention device includes a coating or release agent transferable to the substrate via the printing roller and a servo unit that has a controllable servo motor, wherein in a working position adjustable with the servo unit, the printing roller and the backing roller are in operative connection with one another. The object of the invention is to improve the abadjustability of the generic device. The object is achieved by the servo unit's having a controllable servo motor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a nonwoven fabric for printing, which has good tearing strength and can provide printing finish as good as an art paper at a low cost.
2. Prior Art
Conventionally, various types of nonwoven fabrics have been known as material which could be used in many industrial fields including the civil engineering, carpet and furniture industry, and durable paper products, throwaway materials and coating fabrics. Such nonwoven fabrics are generally classified into a filament nonwoven fabric and a staple nonwoven fabric from the viewpoint of length of fibres which composes the nonwoven fabrics. The filament nonwoven fabric is composed of substantially endless filament fibres which are discharged through a spinning nozzle, whereas the staple nonwoven fabric generally comprises staple fibres of 5-100 mm in length. In respect of the tearing strength, it is preferred to use the filament nonwoven fabric, particularly a high-density filament nonwoven fabric made from synthetic resin such as polyethylene and polypropylene.
On the other hand, to guarantee excellent appearance for products made with such a nonwoven fabric, it is desired to give a high-quality printing process to the nonwoven fabric. Conventionally, for printing onto the filament nonwoven fabric made from polyethylene or polypropylene, there should be required use of expensive special ink such as synthetic-paper ink, ultraviolet-curing ink and electron-beam-curing ink.
However, use of the synthetic-paper ink will greatly impair the printing workability. While, when the UV-curing ink or electron-beam-curing ink is used, an expensive UV-ray generator or electron-beam generator must be employed for curing such ink, so that it becomes difficult to carry out the printing at a low cost. Moreover, in case of UV-curing ink, even after the ink is dried, residual reaction initiator and unreacted monomer smell unpleasantly, thereby deteriorating the working atmosphere.
The offset printing is widely known as a suitable method for attaining a low-cost and high-quality printing. However, such synthetic resin as polyethylene and polypropylene will be affected by a high-boiling-point solvent contained in the offset print ink, so that when the offset printing is carried out onto the nonwoven fabric made from polyethylene or polypropylene, the nonwoven fabric is swelled and unevenness occurs on the surface thereof. Moreover since the nonwoven fabric is originally inferior in the surface smoothness resulting in a poor ink-transfer property, that is, an ink attached to a blanket of an offset printing machine would not readily be transferred to the surface of the nonwoven fabric, the printing quality can not be improved as high as the level of the art papers. The ink-setting property of the nonwoven fabric is also poor so that when a plurality of the printed nonwoven fabric are stacked one another, the ink once transferred to the surface of the underlying nonwoven fabric could be re-transferred to the underside of the overlying one, this being known in general as a matter of set-off.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to realize high quality offset printing onto nonwoven fabrics, particularly, filament nonwoven fabrics, and to provide printing finish as excellent as the level of the art papers.
To achieve this object, according to the present invention, there is provided an nonwoven fabric for printing, at least one side of which is provided with an ink-setting layer comprising one or more resins selected from the group consisting of acrylic resins, synthetic rubbers and polyester resins.
From the viewpoint of tearing strength, it is preferred to use a filament nonwoven fabric composed of synthetic filament fibres such as polyamide, polyester, polyethylene and polypropylene. It is also preferred that the surface smoothness (which is determined by a surface roughness [Rz]) of the nonwoven fabric is 50 μm or less, particularly 30 μm or less. Though the weight of a generally known nonwoven fabric is 70 g/m 2 or more, in the present invention, it is preferred to use the fabric having a weight of about 50 g/m 2 or less.
The ink-setting layer can be obtained by drying and curing a resin composition containing one or more resins selected from the group consisting of acrylic resins, synthetic rubbers and polyester resins. As the acrylic resins, there can be mentioned acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate, methacrylic esters such as methyl methacrylate, ethyl methacylate, butyl methacrylate, lauryl methacrylate and stearyl methacrylate, and copolymers of these esters. In particular the 2-ethylhexyl acrylate-methyl methacrylate copolymer has good adhesion to the surface of nonwoven fabric, resulting in less probability that the ink-setting layer formed on the nonwoven fabric surface should be removed by the blanket. Incidentally, it is preferred that the acrylic resin is used as a composition in an emulsion state or aqueous dispersion. The polyester resins may include polyethylene terephthalate, alkyd resins, unsaturated polyester resins and maleic resins. The synthetic rubbers may include methacrylic ester-butadiene copolymers (MBR), methacrylic ester-styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer and carboxylate derivatives or alkali-reactive substituted derivatives thereof. In particular, the ink-setting layer mainly containing MBR can be a barrier layer for effectively preventing the nonwoven fabric from being damaged by the printing ink and shows a good ink-transfer property.
The solid content in these resin material is 10 to 60% by weight, preferably 15 to 45% by weight. When the ink-setting layer is formed by using one or more of these acrylic resins as main resin component, 0.1 to 5% by weight, preferably 1 to 2% by weight of trimethylolmelamine may optionally be added as a cross-linking agent for cross-linking the resin three-dimensionally. 0.1 to 0.5% by weight, preferably 0.1 to 0.2% by weight of a catalyst, e.g., an organic amine hydrochloric acid salt, may be added for promoting the cross-linking. 0.2 to 0.8% by weight of a dispersant, which may be a composition mainly containing a sodium polyacrylate homopolymer is also an optional additive. 50% by weight or less, preferably 20 to 40% by weight in total of fillers such as titanium dioxide, calcium carbonate, clay and the like, may also be added to improve the surface smoothness, ink-absorbability and fixing ability of the ink-setting layer. About 2% by weight of a moisture-retention component, such as casein, starch and the like, may additionally be incorporated to prevent occurrence of static electricity so as to increase the traveling speed on printing. Further, a mildewproofing agent comprising organic nitrogen compounds, for example, a pigment and a defoaming agent may be added upon necessity. Incorporation of the cross-linking agent and catalysts will make it possible that the ink-setting layer is formed at a lower temperature, which is therefore particularly preferable where the raw material of the nonwoven fabric to be prepared has such low heat resistance as of polyethylene or polypropylene.
The amount of the ink-setting layer formed on one surface of the ink-setting layer should be, in general, of the order of 7 g/m 2 or more, preferably 10 to 20 g/m 2 , when measured as a solid component, though it may change depending on the kind of the resin component, the kind of the nonwoven fabric material and the printing method. Thus, the ink-setting layer can be effectively used as a barrier layer which prevents the nonwoven fabric from being swelled by a petroleum high-boiling solvent contained in the offset printing ink.
The ink-setting layer can easily be formed by coating an ink-setting-layer resin composition, in accordance with a known method employing a reverse roll coater or air knife coater, for example. The resin composition is then subjected to drying and cross-linking, with or without heating. When a heat cross-linking process is carried out, a special care should be paid so that the nonwoven fabric is not damaged nor shrunk by heat. For example, when an ink-setting layer mainly containing a synthetic rubbers is formed on a nonwoven fabric made from polyethylene, the heat cross-linking process should be carried out at a temperature below 120° C. by incorporation of the cross-linking agent and catalysts, otherwise, cross-linking should be completed without heating. On the other hand, since a nonwoven fabric made from polyester has a high heat resistance, it is permitted to carry out the cross-linking process at about 100° to 170° C. when the ink-setting layer mainly containing the rubber resin is formed on a polyester nonwoven fabric.
When a nonwoven fabric made from polyethylene or polypropylene which is inferior in the heat resistance is used as a printing medium, as described above, a special care should be paid to prevent the said nonwoven fabric from being damaged in the heating process during formation of the ink-setting layer. In particular, when a nonwoven fabric having a weight of 50 g/m 2 or less is utilized, the thickness thereof should be small so much, so that the said nonwoven fabric is very likely to be transformed or shrunk by heat treatment. To avoid this problem, the temperature of heat treatment should not exceed 100° C., more preferably not exceed 85° C. However, such a temperature will not be sufficient to complete the cross-linking reaction of the resin component of the ink-setting layer. Even if the reaction itself is possible, it will require a considerably long time, thereby greatly impairing the productivity. Therefore, so-called low temperature cross-linking agent is preferably incorporated into the ink-setting-layer composition. The low temperature cross-linking agent will be hereby defined as an agent capable of cross-linking the resin component at a temperature less than 100° C., preferably less than 85° C., in a relatively short time, for example in a few minutes, without any catalyst, or an agent capable of cross-linking the resin component at such a relatively low temperature in such a relatively short period of time, in the presence of one or more suitable catalysts.
As the low-temperature cross-linking agent, there can be mentioned epoxy-base cross-linking agents, oxazoline-base cross-linking agents and zirconium-base cross-linking agents such as a zirconium ammonium carbonate. Above all, tetrafunctional epoxy resins containing tertiary amines can completely cross-link the resin composition of the ink-setting layer in a relatively short period of time. Moreover, in the present invention, it is also possible to use trimethylol melamine, hexamethylol melamine and diethylene urea as the low-temperature cross-linking agent. However, in such a case, it is preferred to incorporate an organic amine hydrochloric acid salt as a catalyst with the cross-linking agent. In practice, the low-temperature cross-linking agent is blended preferably at a ratio of 0.1 to 5% by weight, more preferably 1 to 2% by weight to the ink-setting-layer resin composition. Too much incorporation of the low-temperature cross-linking agent would be costly without yielding a remarkable advantage, whereas too less incorporation would prolong a period of time to be required for cross-linking reaction.
As having been described herein, it is preferred to incorporate a filler such as titanium dioxide, calcium carbonate and clay, to improve the surface smoothness, ink absorbability and fixing ability of the ink-setting layer. From further experiments on the matter, the inventors have found that when non-calcined clay, titanium dioxide, calcium carbonate and/or calcined clay are blended at predetermined ratios respectively, the ink absorbability, drying ability and fixing ability of the ink-setting layer can be markedly improved, which will reduce the printing time and improve the print quality.
More particularly, the non-calcined clay is blended at a ratio of 10 to 40% by weight to the total amount of the resin composition. No particular result could be obtained by incorporation of less than 10% by weight of the non-calcined clay, while it is incorporated in an amount of more than 40% by weight, a dispersing stability of the resin composition would be lowered. Incidentally, the non-calcined clay means a clay which is not calcined, which is generally referred to as a kaolin clay. Preferably, the average particle size of the non-calcined clay to be incorporated is about 0.5 μm.
While, titanium dioxide is blended at a ratio of 1 to 15% by weight to the total amount of the resin composition. Incorporation of titanium dioxide in a ratio less than 1% does not bring a notable advantage, while when more than 15% by weight, the manufacturing cost of the ink-setting layer resin composition should be increased because titanium dioxide is very expensive, and the absorbability, drying ability and fixing ability to printing ink be deteriorated because the absorbability to the ink solvent of the ink-setting layer is decreased. A preferable example of titanium dioxide is a rutile type one having an average particle size of about 0.26 μm.
With respect to calcium carbonate and calcined clay, it is preferred to use calcined clay in a relatively large amount when well-glazed finish is required for the printing surface of the nonwoven fabric, while when mat finish is required, it is preferred to use calcium carbonate in a relatively large amount. Namely, the amount ratios/ratio of calcium carbonate and/or calcined clay should be changed in the range from 1 to 10% by weight to the total amount of the resin composition. When the blending ratio of calcium carbonate is less than 1% by weight, the ink-setting-layer obtained would have an insufficient ink-absorbability. While, when the ratio is more than 10% by weight, the solvent of the printing ink would be excessively absorbed in the ink-setting layer so that the gloss after the print process may be lost, and the print quality would be deteriorated. On the other hand, when the blending ratio of calcined clay is less than 1% by weight, no particular result could be obtained in respect to improvement of the ink-absorbability. While, incorporation of calcined clay in a ratio larger than 10% by weight would make it difficult to uniformly mix the ink-setting-layer resin composition. Incidentally, calcined clay means clay which is calcined to be a porous material, and has the same composition as that of ordinary clay.
The above-mentioned fillers are blended at a total ratio ranging from 10 to 50% by weight to the amount of the whole resin composition. When the ratio is less than 10% by weight, no particular filling effect could be obtained, while incorporation of these fillers at a total ratio exceeding 50% by weight would result in deterioration of uniform dispersion of the resin composition.
In the above-described construction, the ink-setting layer will improve the surface smoothness of nonwoven fabric and enhances the ink transfer property or ink fixing ability. The ink-setting layer will also function as a barrier layer which protects the nonwoven fabric from the printing ink, particularly, from the petroleum high-boiling solvent contained therein. A single layer formed on the surface of the nonwoven fabric may function as an ink-setting layer, as well as a barrier layer. However, a multiple layer construction is a preferable arrangement of the nonwoven fabric for printing, which has a first layer overlying the surface of the nonwoven fabric and acting in main as a barrier or protection against the printing ink and a second or top layer overlying he first layer and functioning in main to provide an improved ink-fixing property.
Both of the barrier layer and the top layer may be formed substantially in the same manner as mentioned in case of the sole ink-setting layer. However, the resin material used in the barrier layer which directly overlies the surface of the nonwoven fabric should preferably be formed by cross-linking with the above-mentioned low-temperature cross-linking agents. By using such low-temperature cross-linking agents, the resin material can be cross-linked on the nonwoven fabric surface in a shortened time without causing heat damage or heat shrinkage to the nonwoven fabric made from polyethylene or polypropylene which is inferior in the heat resistance. In particular, even when the nonwoven fabric to be processed is so light and thin that the weight thereof is 50 g/m 2 or less, the resin material can be cross-linked without causing any problems. Moreover, by incorporation of the low-temperature cross-linking agent, the ink-setting-layer resin composition is given an excellent resistant property to the solvent contained in the printing ink, which is advantageous for the barrier layer.
With respect to the top layer, it is required to have a high absorbability, drying-ability and fixing-ability to the printing ink, into the resin composition for the top layer should preferably be incorporated 10 to 40% by weight of non-calcined clay, 1 to 15% by weight of titanium dioxide and 1 to 10% by weight of calcium carbonate and/or calcined clay.
Accordingly, a preferred embodiment of the nonwoven fabric for printing according to the present invention comprises laminating on at least one surface of the nonwoven fabric (i) a barrier layer which is formed by cross-linking a first resin composition below 100° C. with a low-temperature cross-linking agent, the first resin composition including one or more resins selected from the group consisting of acrylic resins, synthetic rubbers and polyester resins, and (ii) a top layer comprising a second resin composition which includes one or more resins selected from the group consisting of acrylic resins, synthetic rubbers and polyester resins, and also includes 10 to 40% by weight of non-calcined clay, 1 to 15% by weight of titanium dioxide, and 1 to 10% by weight of calcium carbonate and/or calcined clay.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Example 1
An ink-setting layer resin composition comprising a synthetic rubber was prepared by uniformly mixing 100 parts by weight of an aqueous mixture including the following ingredients (all parts being defined by weight throughout the specification unless otherwise specified):
______________________________________Dispersant mainly containing 0.6 partssodium polyacrylate homopolymer(ARONDISPEX T-40, produced byTOA GOSEI CHEMICAL INDUSTRY CO., LTD.),Filler consisting of kaolin clay, 47.6 partscalcium carbonate and titanium dioxideSynthetic rubber (CROSSLENE 2M-45A, 14.7 partsproduced by TAKEDA CHEMICAL INDUSTRIESLTD.) and caseinTrimethylol melamine cross-linking agent 1.2 parts(SUMITEX RESIN M-3, produced by SUMITOMOCHEMICAL CO., LTD.)Additives consisting of a catalyst, 0.9 partsdefoaming agent, softening agent, ammoniawater and antisepticWater 35.6 parts______________________________________
Then, the ink-setting layer resin composition was coated on both sides of a polyethylene filament nonwoven fabric (Weight: 50 g/m 2 , LUXER H2050XW, produced by ASAHI CHEMICAL INDUSTRY CO., LTD.) with an air knife coater, in a solid content of 18 g/m 2 , then dried with warm air at 100° C. so as to prepare a nonwoven fabric for printing in accordance with the present invention.
Example 2
An aqueous dispersion high polymer polyester resin (MD1200, produced by TOYOBO CO., LTD., Solid Content: 34%) was coated on both sides of a polyethylene filament nonwoven fabric (Weight: 100 g/m 2 , LUXER H2080XW, produced by ASAHI CHEMICAL INDUSTRY CO., LTD.) in a solid content of 8 g/m 2 with a bar coater around which was wound a wire of 0.5 mm diameter, then dried with warm air at 110° C. so as to form a barrier layer comprising a polyester resin.
Subsequently, a synthetic rubber composition for forming a top layer is formed by uniformly mixing 100 parts by weight of an aqueous mixture which was prepared from the following ingredients:
______________________________________Dispersant mainly containing 0.2 partssodium polyacrylate homopolymer(ARONDISPEX T-40, produced byTOA GOSEI CHEMICAL INDUSTRY CO., LTD.),Filler consisting of kaolin clay, 39.7 partscalcium carbonate and titanium dioxideSynthetic rubber (CROSSLENE 2M-45A, 16.0 partsproduced by TAKEDA CHEMICAL INDUSTRIESLTD.) and caseinTrimethylol melamine cross-linking agent 1.1 parts(SUMITEX RESIN M-3, produced by SUMITOMOCHEMICAL CO., LTD.)Additives consisting of a catalyst, 0.7 partsdefoaming agent, softening agent, ammoniawater and antisepticWater 42.3 parts______________________________________
The synthetic rubber composition thus prepared was coated on the barrier layer formed as described above on both sides of the nonwoven fabric so that the solid content became 10 g/m 2 , then was dried to form a top layer. As a result, another nonwoven fabric for printing was prepared in accordance with the present invention.
Example 3
An emulsion comprising 2-hexylacrylatemethylmethacrylate (589-341E, SAIDEN CHEMICAL CO., LTD. Solid Content: 40%) was coated on one side of a polyester nonwoven fabric (Weight: 50 g/m 2 , YPA-50, produced by ASAHI CHEMICAL INDUSTRY CO., LTD.) with a bar coater around which a wire of 0.5 mm diameter so that the solid content became 10 g/m 2 , then dried with warm air at 100° C., so as to prepare an nonwoven fabric for printing one side of which was coated with an ink-setting layer comprising an acrylic resin.
Example 4
An aqueous dispersion high polymer polyester resin (MD1200, produced by TOYOBO CO., LTD., Solid Content: 34%) was coated on both sides of the same polyester filament nonwoven fabric as used in Example 3 with a bar coater around which was wound a wire of 0.3 mm diameter so that the solid content became 6 g/m 2 , then dried with warm air at 100° C., hereby forming a first layer comprising a polyester resin.
Subsequently, the same ink-setting-layer resin composition as prepared in Example 1 was coated on the first layer with a bar coater of 0.5 mm diameter so that the solid content became 10 g/m 2 , then was dried with warm air at 100° C., so as to form a top layer. Thus, a nonwoven fabric for printing one side of which was laminated with the first anchor layer and the top layer was obtained.
With the nonwoven fabrics respectively obtained by Examples 1 to 4 were subjected to multi-color printing with an offset multi-color printer (ROLAND REKORD, a four-color offset printing machine). As a printing ink, an ordinary offset printing ink which contains a large amount of a high-boiling-point petroleum (kerosine type) solvent was used. The printing machine ran at a speed of 7000 sheets per hour with a standard drum, and the damping water was H solution.
For comparison, the nonwoven fabrics respectively used in Examples 1 to 3 were directly used as Comparative Examples 1 to 3 without forming any ink-setting-layer and barrier/top laminated layers thereon, which were subjected to the same offset printing as applied to the nonwoven fabrics of Examples 1 to 5. Moreover, a polyethylene nonwoven fabric for printing on the market was used as Comparative Example 4, and another nonwoven fabric for printing on the market to which a filler was added was used as Comparative Example 5. With respect to the nonwoven fabrics for printing used as Comparative Examples 4 and 5, special types of printing inks were used, namely an alkyd oil ink in Comparative Example 4 and a printing ink generally utilized for printing onto synthetic papers which includes a relatively small quantity of a solvent in Comparative Example 5. Besides, the offset printing condition to these Comparative Examples 4 and 5 was the same as in Examples 1 to 4.
The evaluation concerning the ink-fixing ability, print quality, printing speed and problems caused by the static electricity on the offset printing to these Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 1.
TABLE 1______________________________________ Ink-Fix Print Printing Trouble by Static Ability Quality Speed Electricity______________________________________Example 1 Good Good Good GoodExample 2 Good Good Good GoodExample 3 Good Good Good GoodExample 4 Good Good Good GoodCom. Ex. 1 Bad Fair Fair BadCom. Ex. 2 Bad Fair Fair BadCom. Ex. 3 Bad Bad Fair BadCom. Ex. 4 Fair Fair Fair FairCom. Ex. 5 Good Good Good Good______________________________________
From the results of Table 1. it is clearly seen that in the nonwoven fabric for printing prepared in accordance with the present invention, even if an ordinary, low-priced offset printing oil ink is used for printing,. the ink-fixing ability is so good that there is no probability of set-off of the ink, high print quality and good printing speed can be guaranteed and no trouble resulting from the static electricity occur. On the other hand, though good results can be seen in Comparative Example 5, an extremely expensive special ink was used therefor, thus the printing cost becomes very high in this case.
Example 5
2 parts by weight of isopropyl alcohol, 2 parts by weight of an epoxy-base cross-linking agent (A-52, produced by MITSHUBISHI GAS CHEMICAL CO., INC.) and 2 parts by weight of water were uniformly mixed together. Then, to the mixture were further added 80 parts by weight of an acrylic resin (SAIBINOL X-590-357E-4, produced by SAIDEN CHEMICAL CO., LTD.) and 14 parts by weight of water. The resultant mixture was uniformly mixed together so as to prepare an acrylic resin composition (resin solid content: 32%) for a barrier layer. Subsequently, the acrylic resin composition was coated twice on both sides of the same polyethylene filament nonwoven fabric (Weight: 50 g/m 2 , LUXER H2050XW, ASAHI CHEMICAL CO., LTD.) as used in Example 1 with an air knife coater so that the dry weight thereof became 10 g/m 2 respectively, then was dried at 80° C. for 1 minute for cross-linking, so as to form a barrier layer.
Thereafter, a synthetic rubbers composition having the same blending contents as of the ink-setting layer resin composition in Example 1 was prepared. Then, the resin composition was coated on the barrier layer with a bar coater around which was wound a wire of 0.5 mm diameter so that the dry weight became 10 g/m 2 , and was dried with warm air at 100° C., so as to form a top layer. In such a manner, a nonwoven fabric for printing both sides of which were laminated with the barrier layer and the top layer was obtained.
Example 6
A nonwoven fabric for printing both sides of which were respectively laminated with a barrier layer and a top layer was obtained in the same manner as described in Example 5 except that the blending contents of the resin composition for the barrier layer was changed as described below (resin solid content: 36%), and the blending contents of the resin composition for the top layer was changed to that of the top layer in Example 2.
The above-mentioned blending contents of the resin composition for the barrier layer were as follows:
______________________________________SAIBINOL X-590-357E-4 80 partsK-1020 (Oxazoline crosslinking agent, 10 partsproduced by NIPPON SHOKUBAI KAGAKUKOGYO CO., LTD.)CAT-A (cross-linking agent, produced by 5 partsNIPPON SHOKUBAI KAGAKU KOGYO CO.,LTD.)Water 5 parts______________________________________
Example 7
A nonwoven fabric for printing both sides of which were respectively laminated with a barrier layer and a top layer was obtained in the same manner as described in Example 5 except that the blending contents of the resin composition for the barrier layer is changed as described below (resin solid content: 32.5%).
______________________________________SAIBINOL X-590-357E-4, 80 partsAC-7 (zirconium ammonium carbonate, 4 partsproduced by DAIICHI KIGENSO KAGAKUKOGYO CO., LTD.)Water 16 parts______________________________________
Example 8
Another nonwoven fabric for printing both sides of which were respectively laminated with a barrier layer and a top layer was obtained in the same manner as in Example 5 except that the blending contents of the resin composition for the barrier layer is changed as described below (resin solid content: 33.8%), and the blending contents of the resin composition for the top layer is changed to that of top layer in Example 2.
______________________________________SAIBINOL X-590-357E-4, 80 partsBAYCOAT (zirconium ammonium carbonate, 4 partsproduced by NIPPON LIGHT METAL CO., LTD.)Water 16 parts______________________________________
Example 9
A synthetic rubbers composition was obtained by uniformly mixing 100 parts by weight of an aqueous mixture which was prepared from the following ingredients:
______________________________________Dispersant mainly containing 0.2 partssodium polyacrylate homopolymer(ARONDISPEX T-40, produced byTOA GOSEI CHEMICAL INDUSTRY CO., LTD.),Filler consisting of kaolin clay, 47.6 partscalcium carbonate and titanium dioxideSynthetic rubber (CROSSLENE 2M-45A, 16.0 partsproduced by TAKEDA CHEMICAL INDUSTRIESLTD.) and caseinEpoxy-base cross-linking agent (A-521, 1.2 partsproduced by MITSHUBISHI GAS CHEMICALCO., INC.Isopropyl alcohol 1.2 partsAdditives consisting of a catalyst, 0.9 partsdefoaming agent, softening agent, ammoniawater and antisepticWater 32.9 parts______________________________________
Then, the obtained synthetic rubber composition was coated twice on both sides of a polyethylene long-stock nonwoven fabric (LUXER H2050XW) with an air knife coater so that the dry weight became 10 g/m 2 , then was dried at 80° C. for 1 minute for cross-linking, thus obtaining a nonwoven fabric having a single-layer ink-setting layer on each side thereof.
The nonwoven fabrics obtained respectively in Examples 5 to 9 were subjected to offset printing operation under the same condition as in Examples 1 to 4. to find that a good printing state can be similarly obtained in either case. Thus, with such nonwoven fabrics for printing prepared according to the present invention, even if an ordinarily used, low-priced offset printing oil ink is used for printing, there can be obtained a high-quality printing effect which is substantially equal to the art paper.
Example 10
______________________________________SAIBINOL X-590-357E 80.0 partsSUMITEX RESIN M-3 2.0 partsACX (Catalyst consisting of an organic 0.2 partsamine hydrochloric acid salt, producedby SUMITOMO CHEMICAL CO., LTD.)Water 07.8 parts______________________________________
An acrylic resin component having the above composition was coated on both sides of a polyethylene filament nonwoven fabric (LUXER H2050XW) with an air knife coater so that the dry weight became 10g/m 2 , then was dried with warm air so as to form a barrier layer.
Subsequently, a synthetic rubber composition for a top layer was prepared by uniformly mixing the following composition including non-calcined clay, titanium dioxide and calcined clay. Thereafter, the synthetic rubber composition was coated on the barrier layer with a bar coater around which was wound a wire of 0.5 mm diameter so that the dry weight became 10 g/m 2 , then was dried with warm air at 100° C. for 1 minute, so as to obtain a top layer. Thus, a nonwoven fabric for printing both sides of which were respectively laminated with the barrier layer and the top layer.
______________________________________Non-calcined kaolin clay 28.0 partsTitanium dioxide 8.0 partsCalcined clay 4.0 partsCROSSLENE 2M-45A 14.0 partsMethylol melamine 1.3 partsACX 0.1 partsCasein 2.2 partsAmmonia water 0.4 partsDELTOP SP (Antiseptic, produced by 0.02 partsTAKEDA CHEMICAL INDUSTRIES LTD.)SURFINOL 440-1 (Defoaming agent, 0.04 partsproduced by NISSHIN KAGAKU CO., LTD.)Turkey red oil 0.09 partsARON T-40 0.8 partsWater 40.85 parts______________________________________
When offset printing was carried out onto the nonwoven fabric thus obtained, the resultant print had good gloss and high quality equivalent to the art paper.
Example 11
A nonwoven fabric for printing both sides of which were respectively laminated with a barrier layer and a top layer was obtained in the same manner as described in Example 10 except that in the resin composition for the barrier layer in Example 10. 17 parts of non-calcined kaolin clay. 13 parts of titanium dioxide and 7 parts of calcium carbonate were incorporated as fillers, and the amount of ARON T-40 was changed into 0.2 part. When offset printing was carried out onto this nonwoven fabric, the resultant print had mat finish and a high-quality print state equivalent to the art paper, as well.
Example 12
A nonwoven fabric for printing both sides of which were respectively laminated with a barrier layer and a top layer was obtained in the same manner as described in Example 10 except that in the resin composition for the barrier layer in Example 10, 40 parts of non-calcined kaolin clay, 2 parts of titanium dioxide and 8 parts of calcium carbonate were incorporated as fillers. When offset printing was carried out onto this nonwoven fabric, the good results were similarly obtained.
Example 13
A nonwoven fabric for printing both sides of which were respectively laminated with a barrier layer and a top layer was obtained in the same manner as described in Example 10 except that in the resin composition for the barrier layer in Example 10, 31 parts of non-calcined kaolin clay. 5 parts of titanium dioxide and 4 parts of calcium carbonate were incorporated as fillers, and the amount of ARON T-40 was changed into 0.2 part. This nonwoven fabric was proved to be a suitable printing medium for offset printing.
Example 14
Without providing a barrier layer, a sole ink-setting layer was formed by coating the same resin composition for the top layer as in Example 10 on each side of a polyethylene filament nonwoven fabric (LUXER H2050XW) with a bar coater around which a wire of 0.5 mm diameter so that the dry weight became 20 g/m 2 , then were dried at 80° C. for 1 minute. Thus, a nonwoven fabric for printing both sides of which were provided with the single ink-setting layer was obtained. When offset printing was carried out onto the nonwoven fabric, the resultant print had good gloss, and the print state was as good as that of art paper.
Comparative Example 6
A nonwoven fabric for printing both sides of which were respectively laminated with a barrier layer and a top layer was obtained in the same manner as described in Example 10 except that in the resin composition for the barrier layer in Example 10, 31 parts of non-calcined kaolin clay, 9 parts of titanium dioxide were incorporated as fillers, and the amount of ARON T-40 was changed to 0.2 part. When offset printing was carried oui onto this nonwoven fabric in the same manner as in Example 10, it took a considerable time to completely dry and set the printing ink onto the surfaces of the nonwoven fabric. Therefore, the amount of the printing ink to be absorbed onto the surfaces of the nonwoven fabric should be decreased, resulting in a poor coloring. Moreover, due to poor ink-setting property, the set-off problem was noted.
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A nonwoven fabric, particularly composed by long-stock synthetic resin yarns such as polyethylene and polypropylene is provided at one or both surfaces thereof with an ink-setting layer formed by coating, drying and curing a resin composition containing some of acrylic resins, synthetic rubbers and polyester resins. The ink-setting layer is excellent in the transfer property and fixing ability to an oil ink which is ordinarily used for offset printing, and prevents the nonwoven fabric from being swelled or transformed by a petroleum high-boiling-point solvent contained in the oil ink. Preferably, a low-temperature cross-linking agent is incorporated with the resin composition of the ink-setting layer so as to complete cross-linking of the resin composition at a low temperature at which heat shrinkage or heat damage of the nonwoven fabric will not be caused, in a shortened period of time. Moreover, when 10 to 40% by weight of non-calcined clay, 1 to 15% by weight of titanium dioxide and 1 to 10% by weight of calcium carbonate or calcined clay are incorporated as fillers in the resin composition of the ink-setting layer, the ink-setting layer has improved absorbability, drying ability and fixing ability to a printing ink. A preferable construction of the nonwoven fabric has a first layer containing the low-temperature cross-linking agent and a second layer containing the specific filler ingredients.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of U.S. Provisional No. 61/622,884 filed on Apr. 11, 2012 and entitled “BEHAVIORAL DATA DRIVEN RECOMMENDATION.”
FIELD OF THE INVENTION
[0002] The invention related to a comprehensive system and method for making recommendations to a user based on a combination of active and collected data.
BACKGROUND OF THE DISCLOSED SUBJECT MATTER
[0003] Existing recommendation engines are computationally intractable. This is because existing systems attempt to map a known set of data to an unknown set of outcomes. Furthermore, even if existing systems could overcome the above problem, there are limited sets of data on which the system can evaluate to provide recommendations. This results in poor recommendations and eventual obsolescence.
BRIEF DESCRIPTION OF THE DISCLOSED SUBJECT MATTER
[0004] The disclosed subject matter provides a comprehensive system and method for making recommendations to a user based on a combination of active and collected data. More specifically, in combination with an online network management system, the disclosed subject matter bases its recommendations on (i) information related to the IT devices used on a network; (ii) network events; (iii) relational data; and/or (iv) contextual data.
BRIEF DESCRIPTION OF THE FIGURES
[0005] FIG. 1 depicts an embodiment of a contextual data system architecture.
[0006] FIG. 2 depicts an embodiment of a system architecture overview for presenting a recommendation to an IT Administrator.
[0007] FIG. 3 depicts an embodiment of a system architecture showing the flow of information for rating/scoring recommendations.
[0008] FIG. 4 depicts an embodiment of a general interface, or “Dashboard,” of an online network management system.
[0009] FIG. 5 depicts a recommendation, tip, or outcome presented to a user of the online network management system.
[0010] FIG. 6 depicts an embodiment of the See Device Details tab.
[0011] FIG. 7 depicts an embodiment of the See Application Details.
[0012] FIG. 8 depicts an embodiment of community message board posts relating to the recommendation/tip/outcome of FIG. 5 .
[0013] FIG. 9 depicts an embodiment of an Inventory screen displaying all devices and information about all devices on the network.
[0014] FIG. 10 depicts a recommendation/tip/outcome presented to a user in a pop-up screen on the Inventory tab.
[0015] FIG. 11 depicts an embodiment of community message board posts provided to the user after the “See what the community has to say” tab has been selected.
DETAILED DESCRIPTION
[0016] The disclosed subject matter provides a comprehensive system and method for making a recommendation to a user based on a combination of active and collected data. Recommendations are a way to find relevant information in the form of outcomes to provide to the user. Driven from behavioral data, among other types of data, recommendations allow the contextual application disclosed herein to grow and adapt to the specific preferences of each individual user using the application. The recommendation may be a pro-active recommendation provided to the user based on information collected by the online network management system and/or based on the user's desktop interface actions. This recommendation is described in the form of an IT Device (e.g. software, services, an IT product, etc.) recommended to an IT administrator utilizing an online network management system; however, one skilled in the art may apply the system and methods disclosed herein to make various types of recommendations including those relating to non-technology items/services. Further, the terms recommendation or tip are used herein as an outcome presented to the user but a recommendation should not be limited to an item or solution for purchase; a recommendation may also include any type of suggestion or outcome based on relational data and contextual information concerning the user.
[0017] Disclosed in the descriptive text below and in the corresponding figures are exemplary aspects, features, and functionalities that may comprise a behavioral driven system and/or method; however, one may apply any combination of the disclosed features and/or additional features to the innovations disclosed herein. Screenshots are utilized to help describe the features and functionality as well as underlying architecture of the system. The disclosed subject matter may also include an online network management system such as that described in U.S. Pat. Pub. No. 2010/0100778, filed on Jan. 23, 2009 by common inventor Francis Sullivan, which is hereby incorporated by reference in its entirety.
[0018] The disclosed subject matter tracks and stores contextual data of one or more users using a computing system in combination with data captured relating to the user's network—which may be provided by an online network management system such as that disclosed in U.S. Pat. Pub. No. 2010/0100778. Thus, the disclosed subject matter combines information relating to the IT devices used on a network (hardware, software, including the interconnectivity of the same, etc.), network events (e.g. the current status of IT devices), relational data (e.g. other community members/users the user has connected to or message board questions the user has viewed), and contextual data (e.g. what the user is presently viewing). As previously alluded to the system may comprise an online community component which is especially helpful with relational data tracking and analysis. All of these components are fully integrated to determine and provide a user with recommendations.
Events
[0019] Event data comprises network events—in other words, the status of IT devices on the network. Examples of event data include the current status of disk space available on a device, the memory utilization, network utilization, software installation or removal, power fluctuations, warranty expiration, etc.
Relational Data
[0020] Relational data includes information concerning past connections the user has made in the community component. Some examples of relational data include other network users (IT Admins) the user has connected to, questions/posts the user has read on the community message boards, surveys the user had participated in or created, etc.
Context
[0021] Context, or contextual data, comprises the current set of information that the user is viewing. For example, if the user is viewing a Dell® (a registered trademark of Dell Computer Corporation) laptop on an inventory page of an online network management system then the context is the Dell® laptop and everything about the laptop. Context may also include to some extent the environment that the Dell® laptop operates in (e.g. the network).
[0022] Referring now to FIG. 1 which depicts an embodiment of a contextual data system architecture. Context may be a hybrid application. In one embodiment, the desktop application 102 is installed on-device behind the user's firewall and runs in the context of her network and other contextual data collectors (such as a community component 104 collecting the user's network community actions and market component 106 collecting industry trend information) are traditional web applications that run in hosted data centers. Thus, the user data 100 such as her view of the desktop is communicated and combined with the web applications.
[0023] In one embodiment, communicating context between the applications may be performed by taking the raw relational data and translating it into a n-dimensional space. The translated data is then combined across applications and a behavioral mask is applied to it. This behavioral mask is derived from the previous actions that the user and users like that user have taken in the past.
[0024] Data components 100 such as those described previously, Desktop 102 , Community 104 , and Marketview 106 , capture contextual data and are combined to form workflow context data 108 to be used in presenting a recommendation to the user 110 . An online network management system may also provide event data concerning network events and asset data relating to network assets (e.g. the physical and virtually components and equipment attached to the network).
[0025] FIG. 2 depicts an embodiment of a system architecture overview for presenting a recommendation to an IT Administrator 110 . Data sources 100 , such as those of FIG. 1 , provide contextual data to create workflow context 108 , and also provide event, network asset, and other relational data to a recommendation engine 122 . Potential outcomes 120 are also provided to the recommendation engine 122 which then determines a recommendation 124 to present to the user, here an IT Administrator 110 .
Outcomes
[0026] Because there is so much data spread out across many environments, traditional recommenders are computationally intractable as an outcome producer cannot map a known set of data to an unknown set of outcomes. Alternatively, the disclosed subject matter provides a well-defined set of outcomes 120 and maps this to a well-known set of data 100 and 108 —an approach functionally the reverse of traditional clustering/recommendation systems/methods.
Types of Recommendation Outcomes
[0027] Examples of Purchasing
Purchase a product or service Connecting users with vendors Industry buying cycle analysis (people will often buy the same products at the same time)
[0031] Examples of Social
Information about how a user fits with an industry or trend Connecting users with other users Connecting users with questions they might have Connecting users with pertinent answered questions Connecting users with questions they might have answers to
[0037] Examples of Environmental
Drawing a conclusion from a set of environmental data Upgrade information about products on their network Prioritizing errors and alerts based on past behavior
Rating/Scoring Recommendations
[0041] FIG. 3 depicts an embodiment of a system architecture showing the flow of information for rating/scoring recommendations. One aspect of the disclosed subject matter includes automated-tuning recommendations whereby recommendations are provided based on users' actions to previous recommendations for other users 130 . A component score of similar users and their preferences is added to pre-guess drift and interest for users that then will be adjusted through further use. This allows, for example, the ability to problem solve using existing network data without user interaction. The recommendation scoring 132 has as inputs workflow context 108 and previous behavior 130 . Based on the inputs, the set of possible recommendations is scored. Recommendation instance generation 134 passes off to recommendation instance scoring 136 and outputs the final ranked recommendation. In one embodiment multiple recommendations are provided. In another embodiment, only the highest ranked recommendation is displayed to the user.
Example Recommendations
[0042] For example, operating system adoption happens along an exponential curve. It has a very slow start and an adoption curve different between industries. One major concern of an IT Admin is deciding when is the right time to adopt a new operating system, such as a new version of Windows® (a registered trademark of Microsoft Corporation). Using contextual and relational information, the disclosed subject matter may recommend to an IT Admin to adopt a new operating system version based on similar companies to that IT Admin and present industry information that will help the IT Admin make a decision. Continuing with this example, if the IT Admin is administrating a network for a law firm sized 25-50, the disclosed subject matter can aggregate information on similar companies (law firms with 25-50 employees) and evaluate when or if other similarly situated companies have already upgraded or are in the process of upgrading. This can provide valuable information to the IT Admin on when to upgrade. As noted earlier, the information related to similarly situated companies can be provided by an online network management system.
[0043] As another example, often vendors struggle to find clients who need their solutions and IT Admins struggle to find vendors that have credible solutions that might meet the IT Admins need. By looking at network information and behavioral data vendors may be recommended to users. Continuing with this example, company A is a company that helps manage cloud services; unfortunately, adoption of cloud services has been sporadic and finding potential customers has been difficult. The presently disclosed subject matter can identify current cloud services to recommend to particular users in need of cloud services. A behavioral mask may also be applied to this recommendation which would only recommend Company A to potential purchasers who have used Company A previously. This example uses data from three data sources: the desktop 102 , community 104 , and marketview 106 .
[0044] Making correct IT decisions can be difficult; however, by collecting and using network information and behavioral data, situations where an IT Admin is similar or dissimilar to his/her peer group may be identified. Currently, virtualization technology is one of the most important choices IT companies are making; however, the decision to utilize virtualization is a decision that involves completely overhauling the backend of most IT companies. As a result, IT Admins would benefit knowing that their decision is similar to their peers.
[0045] Further, many industries operate on predictable buying cycles. By looking at network information and behavioral data, buying cycles may be identified and products recommended to a user.
[0046] FIGS. 4-11 are screenshots showing aspects of the disclosed subject matter. FIG. 4 depicts an embodiment of a general interface, a “Dashboard,” of an online network management system. The Dashboard allows an IT Admin to monitor and manage a network of IT devices.
[0047] FIG. 5 depicts an embodiment of a Tip, referred to herein also as a recommendation or outcome, presented to the online network management system user. Here, the outcome is to remove a piece of software based on a community of other IT Admins utilizing the online network management system. The recommendation is accompanied by information relating to the recommendation for the user, such as viewing device details about devices with the identified software, application details about the software itself, and community reviews from the online community message board—all designed to provide the user with information to help in deciding whether or not to accept the recommendation. In this particular embodiment, the recommendation is a pop-up screen which automatically displays according to a pre-determined criteria, such as the status of network devices or actions by the user, but the recommendation may also require an opt-in from the user.
[0048] FIG. 6 depicts an embodiment of the See Device Details tab. Here, the user is presented with all the network devices which are currently running the identified software for removal and is able to select a device to see more detailed information.
[0049] FIG. 7 depicts an embodiment of the See Application Details whereby the user is presented with information relating to the software application.
[0050] FIG. 8 depicts an embodiment of the community message board posts relating to the Tip of FIG. 5 .
[0051] FIG. 9 depicts an embodiment of an Inventory screen displaying all devices and information about all devices on the network.
[0052] FIG. 10 depicts an embodiment of a Tip presented to a user in a pop-up screen on the Inventory tab. This tip relates to the age of the network device julies-pc, captured by the online network management system, and provides a recommendation based on the actions of similar IT Admins. Here, the user is also provided with a Request for Quote option as well as the ability to search the community message boards for information relating to replacing a pc.
[0053] FIG. 11 depicts an embodiment of the community message with exemplary board posts that may be provided to the user after the “See what the community has to say” tab has been selected.
[0054] An additional aspect of the disclosed subject matter includes utilizing sentiment tracking in the form of tagging positive and negative posts in the community component. Further, user purchases may be traced backwards to identify relational and contextual data that may have led to the purchase itself. This data may then be tagged as positive or negative and utilized in additional user recommendations.
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A method and computer readable medium for a fully integrated IT recommendation system, comprising receiving contextual data comprising information regarding what a user is currently viewing; receiving relational data information regarding the user's previous interaction with an online community related to IT administrators; receiving market view data comprising industry trend information related to IT, the industry particular to the user's industry. The contextual data, the relational data, and the marketing data make up the workflow context. The workflow context is passed to a recommendation engine which evaluates the workflow context and selects one or more of a set of outcomes, the outcome(s) are directly related to the workflow context; and presenting said one or more selected outcomes to said user.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of information or data processor architecture. More specifically, this invention relates to the field of implementing a computational or mathematical unit in a processor achieving power control via varying instruction issuance.
BACKGROUND
[0002] Information or data processors are found in many contemporary electronic devices such as, for example, personal computers, personal digital assistants, game playing devices, video equipment and cellular phones. Processors used in today's most popular products are known as hardware as they comprise one or more integrated circuits. Processors execute software to implement various functions in any processor based device. Generally, software is written in a form known as source code that is compiled (by a complier) into object code. Object code within a processor is implemented to achieve a defined set of assembly language instructions that are executed by the processor using the processor's instruction set. An instruction set defines instructions that a processor can execute. Instructions include arithmetic instructions (e.g., add and subtract), logic instructions (e.g., AND, OR, and NOT instructions), and data instructions (e.g., move, input, output, load, and store instructions). As is known, computers with different architectures can share a common instruction set. For example, processors from different manufacturers may implement nearly identical versions of an instruction set (e.g., an x86 instruction set), but have substantially different architectural designs.
[0003] Within a processor, numerical data is typically expressed using integer or floating-point representation. Mathematical computations within a processor are generally performed in computational units designed for maximum efficiency for each computation. Thus, it is common for a processor architecture to have an integer computational unit and a floating-point computational unit. As the use of graphic processing and scientific computing has expanded, the use of a processor's integer and floating-point mathematical capabilities has been increasing. Other factors, such as use for audio processing, are also contributing to an increased use of a processor's mathematical capabilities. To accommodate these and other needs, and to meet the ever growing demand for increased integer and floating-point performance, the computational capability of processors is continually evolving.
[0004] When performing operations, including integer or floating-point computations, power virus code may occasionally cause the processor (or an operational unit) to consume more power than normal. Generally, power virus code comprises instructions that don't have any practical use; the code simply causes wasted power and operational cycles within the processor. Examples include code that causes unnecessary register-to-register data moves, operand reordering for commutative equations (e.g., addition or multiplication) or wait or no-op (no operation) instructions. In addition to wasting power and operational cycles, power virus code can cause the internal operating temperature of the processor to rise beyond specified performance parameters. Typically, an over-temperature condition causes a reset event to occur and the entire processor stops and is reset in accordance with a reset protocol.
BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION
[0005] An apparatus is provided for modifying instruction issuance in a processor (or computational unit thereof) in response to power consumption exceeding a threshold. The apparatus comprises a decoder for decoding instructions to be performed and a power consumption monitor for determining when power consumption within the processor exceeds a threshold. Upon that determination, a scheduler begins modify instruction issuance to one or more execution units until the power consumption is below the threshold. The modification of instruction issuance can be to slow instruction issuance or cease instruction issuance for a time period or until the power consumption is below the threshold.
[0006] In another embodiment, an apparatus is provided for modifying instruction issuance in a processor (or computational unit thereof) in response to power consumption exceeding a threshold for a particular instruction. The apparatus comprises a decoder for decoding instructions to be performed and providing a threshold to a power consumption monitor for that instruction. When the power consumption within the processor exceeds a threshold for the particular instruction, a scheduler begins modify issuance of the particular instruction to execution units until the power consumption is below the threshold. The modification of instruction issuance can be to slow issuance of the particular instruction or cease issuance of the particular instruction for a time period or until the power consumption is below the threshold.
[0007] In yet another embodiment, an apparatus is provided for modifying instruction issuance in a processor (or computational unit thereof) in response to power consumption exceeding a threshold. The apparatus comprises a detector capable of determining that an energy event has occurred and a decoder for decoding instructions to be performed. A power consumption monitor determines when power consumption within the processor exceeds a threshold, which can be modified responsive to the detector identifying the occurrence of the energy event (for example, a battery powered device being “unplugged”). When power consumption exceeds the threshold, a scheduler begins modify instruction issuance to one or more execution units until the power consumption is below the threshold. The modification of instruction issuance can be to slow instruction issuance or cease instruction issuance for a time period or until the power consumption is below the threshold.
[0008] A method is provided for controlling power consumption in a processor (or computational unit thereof). The method comprises monitoring power consumption in a processor (or computational unit) and determining that the power consumption of the processor (or computational unit) exceeds a threshold. Thereafter, instruction issuance if modified (such as by slowing or ceasing instruction issuance) within the processor (or computational unit) until the power consumption is below the threshold.
[0009] In another embodiment, a method is provided for controlling power consumption in a processor (or computational unit thereof). The method comprises monitoring power consumption in a processor (or computational unit) and determining that the power consumption of the processor (or computational unit) exceeds a threshold. Thereafter, instruction issuance if modified (such as by slowing or ceasing instruction issuance) within the processor (or computational unit) until the power consumption is below the threshold.
[0010] In yet another embodiment, a method is provided for controlling power consumption in a processor (or computational unit thereof). The method comprises monitoring power consumption in a processor (or computational unit) and determining that the power consumption of the processor (or computational unit) exceeds a threshold that varies upon detecting an occurrence of an energy changing event (such as a battery powered device being “unplugged”). Thereafter, instruction issuance if modified (such as by slowing or ceasing instruction issuance) within the processor (or computational unit) until the power consumption is below the threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Embodiments of the present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
[0012] FIG. 1 is a simplified exemplary block diagram of processor suitable for use with the embodiments of the present disclosure;
[0013] FIG. 2 is a simplified exemplary block diagram of floating-point unit or integer unit suitable for use with the processor of FIG. 1 ;
[0014] FIG. 3 is a flow diagram illustrating an embodiment of the present disclosure; and
[0015] FIG. 4 is a flow diagram illustrating another embodiment of the present disclosure.
DETAILED DESCRIPTION
[0016] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Thus, any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, as used herein, the word “processor” encompasses any type of information or data processor, including, without limitation, Internet access processors, Intranet access processors, personal data processors, military data processors, financial data processors, navigational processors, voice processors, music processors, video processors or any multimedia processors. All of the embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, the following detailed description or for any particular processor microarchitecture.
[0017] Referring now to FIG. 1 , a simplified exemplary block diagram is shown illustrating a processor 10 suitable for use with the embodiments of the present disclosure. In some embodiments, the processor 10 would be realized as a single core in a large-scale integrated circuit (LSIC). In other embodiments, the processor 10 could be one of a dual or multiple core LSIC to provide additional functionality in a single LSIC package. As is typical, processor 10 includes an input/output (I/O) section 12 and a memory section 14 . The memory 14 can be any type of suitable memory. This would include the various types of dynamic random access memory (DRAM) such as SDRAM, the various types of static RAM (SRAM), and the various types of non-volatile memory (PROM, EPROM, and flash). In certain embodiments, additional memory (not shown) “off chip” of the processor 10 can be accessed via the I/O section 12 . The processor 10 may also include a floating-point unit (FPU) 16 that performs the float-point computations of the processor 10 and an integer processing unit 18 for performing integer computations. Additionally, an encryption unit 20 and various other types of units (generally 22 ) as desired for any particular processor microarchitecture may be included.
[0018] Referring now to FIG. 2 , a simplified exemplary block diagram of a computational unit suitable for use with the processor 10 . In one embodiment, FIG. 2 could operate as the floating-point unit 16 , while in other embodiments FIG. 2 could illustrate the integer unit 18 .
[0019] In operation, the decode unit 24 decodes the incoming operation-codes (opcodes) dispatched (or fetched by) a computational unit. The decode unit 24 is responsible for the general decoding of instructions (e.g., x86 instructions and extensions thereof) and how the delivered opcodes may change from the instruction. The decode unit 24 will also pass on physical register numbers (PRNs) from an available list of PRNs (often referred to as the Free List (FL)) to the rename unit 26 .
[0020] The rename unit 26 maps logical register numbers (LRNs) to the physical register numbers (PRNs) prior to scheduling and execution. According to various embodiments of the present disclosure, the rename unit 26 can be utilized to rename or remap logical registers in a manner that eliminates the need to actually store known data values in a physical register. This saves operational cycles and power, as well as decrease latency.
[0021] The scheduler 28 contains a scheduler queue and associated issue logic. As its name implies, the scheduler 28 is responsible for determining which opcodes are passed to execution units and in what order. In one embodiment, the scheduler 28 accepts renamed opcodes from rename unit 26 and stores them in the scheduler 28 until they are eligible to be selected by the scheduler to issue to one of the execution pipes.
[0022] The execute unit(s) 30 may be embodied as any generation purpose or specialized execution architecture as desired for a particular processor. In one embodiment the execution unit may be realized as a single instruction multiple data (SIMD) arithmetic logic unit (ALU). In other embodiments, dual or multiple SIMD ALUs could be employed for super-scalar and/or multi-threaded embodiments, which operate to produce results and any exception bits generated during execution.
[0023] In one embodiment, after an opcode has been executed, the instruction can be retired so that the state of the floating-point unit 16 or integer unit 18 can be updated with a self-consistent, non-speculative architected state consistent with the serial execution of the program. The retire unit 32 maintains an in-order list of all opcodes in process in the floating-point unit 16 (or integer unit 18 as the case may be) that have passed the rename 26 stage and have not yet been committed by to the architectural state. The retire unit 32 is responsible for committing all the floating-point unit 16 or integer unit 18 architectural states upon retirement of an opcode.
[0024] Referring now to FIG. 3 , a flow diagram is shown illustrating the steps followed by an embodiment of the present disclosure for the processor 10 , the floating-point unit 16 , the integer unit 18 or any other unit 22 of the processor 10 . The method begins in step 50 where power consumption of the processor (or any operational unit thereof) is monitored. In one embodiment of the present disclosure, average power is monitored over several operational cycles, for example, in a sigma-delta based accumulator. In other embodiments, an instantaneous power measurement could be used. In still other embodiments power consumption by instruction (or instruction type) could be stored in a table providing an expected power consumption for an instruction when it is decoded (for example, in decoder 24 of FIG. 2 ).
[0025] Next, decision 56 compares the measured or monitored power consumption to a threshold. In one embodiment of the present disclosure, the threshold is a fixed value that is set according to a thermal design point or other parameters of the processor (or operational unit). For example, the threshold could be set to just above the highest power for a known “real” opcode and defining any greater power consumption as a “power virus”. In other embodiments, the threshold is variable upon detection of an occurrence or event (see FIG. 4 below). In still other embodiments, the threshold varies by instruction (or instruction type) responsive to an expected power consumption following decoding of an instruction. In any embodiment, one object of the present disclosure is to avoid overheating the processor or putting too much load on the power supply.
[0026] If the determination of decision 56 is that the monitored power consumption is above the threshold, step 58 begins to modify instruction issuance to the execution units. In one embodiment, the scheduler ( 28 of FIG. 2 ) slows release of instructions to the execution units ( 30 in FIG. 2 ) thereby reducing power consumption. In other cases, the scheduler may cease issuing instructions for a time period or until the monitored power consumption returns to a level below the threshold (as determined by decision 56 ). In still other embodiments, the scheduler may slow or stop issuance of particular instructions determined to be wasteful of power upon execution. In any event, the present disclosure contemplates that power consumption may be controlled in the processor (or any operational unit thereof) by modifying instruction release to execution units to reduce power consumption or to maintain power consumption within certain operational parameters.
[0027] Conversely, if the determination of decision 56 is that the monitored power consumption is not above the threshold, does not modify instruction issuance (step 60 ) and the method returns to step 50 and the process repeats.
[0028] Referring now to FIG. 4 , a flow diagram is shown illustrating the steps followed by another embodiment of the present disclosure for the processor 10 , the floating-point unit 16 , the integer unit 18 or any other unit 22 of the processor 10 . As with FIG. 3 , the method begins in step 50 where power consumption of the processor (or any operational unit thereof) is monitored. In one embodiment of the present disclosure, average power is monitored over several operational cycles, for example, in a sigma-delta based accumulator. In other embodiments, an instantaneous power measurement could be used. In still other embodiments power consumption by instruction (or instruction type) could be stored in a table providing an expected power consumption for an instruction when it is decoded (for example, in decoder 24 of FIG. 2 ).
[0029] The method proceeds to decision 52 where it is determined whether a threshold changing event has occurred. According to the present disclosure, a threshold changing event comprises some change indicating that the threshold should be increased or reduced for power consumption purposes. For example, a laptop computer (such as shown in FIG. 5A ), may operate from line current or from an internal battery. While “plugged in”, one threshold may be set to allow more instructions to be issued than when, for example, it is detected that the device has been “un-plugged” and is operating on battery power. Upon detection of such an event (decision 52 ), the threshold could be reduced (step 54 ), thus slowing the issuance of instructions (from scheduler 28 in FIG. 2 ) to execution units ( 30 in FIG. 2 ) to conserve power consumption. When returned to a line current source, the threshold could be returned or adjust to the former threshold level (again step 54 ).
[0030] Conversely, if the determination of decision 52 is that a threshold changing event has not occurred, the method proceeds to decision 56 , which compares the measured or monitored power consumption to a threshold (which may or may not have been modified in step 54 ). If the determination of decision 56 is that the monitored power consumption is not above the threshold, instruction issuance is not modified (step 60 ) and the routine begins again at step 50 .
[0031] Conversely, if the determination of decision 56 is that the monitored power consumption is above the threshold, step 58 begins to modify instruction issuance to the execution units. In one embodiment, the scheduler ( 28 of FIG. 2 ) slows release of instructions to the execution units ( 30 in FIG. 2 ) thereby reducing power consumption. In other cases, the scheduler may cease issuing instructions for a time period or until the monitored power consumption returns to a level below the threshold (via looping back through the routine of FIG. 4 ). In still other embodiments, the scheduler may slow or stop issuance of particular instructions determined to be wasteful of power upon execution. In any event, the present disclosure contemplates that power consumption may be controlled in the processor (or any operational unit thereof) by modifying instruction release to execution units to reduce power consumption or to maintain power consumption within certain operational parameters.
[0032] Various processor-based devices that may advantageously use the processor (or any computational unit) of the present disclosure include, but are not limited to, laptop computers, digital books or readers, printers, scanners, standard or high-definition televisions or monitors and standard or high-definition set-top boxes for satellite or cable programming reception. In each example, any other circuitry necessary for the implementation of the processor-based device would be added by the respective manufacturer. The above listing of processor-based devices is merely exemplary and not intended to be a limitation on the number or types of processor-based devices that may advantageously use the processor (or any computational) unit of the present disclosure.
[0033] While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.
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Methods and apparatuses are provided for controlling power consumption in a processor (or computational unit thereof). The method comprises monitoring power consumption in a processor (or computational unit) and determining that the power consumption of the processor (or computational unit) exceeds a threshold. Thereafter, instruction issuance if modified (such as by slowing or ceasing instruction issuance) within the processor (or computational unit) until the power consumption is below the threshold. The apparatus comprises a power consumption monitor for determining when power consumption within the processor exceeds a threshold. Upon that determination, a scheduler begins modify instruction issuance to one or more execution units until the power consumption is below the threshold. The modification of instruction issuance can be to slow instruction issuance or cease instruction issuance for a time period or until the power consumption is below the threshold.
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The present invention relates generally to a specialty cleaning apparatus intended primarily for use in or near oil fields. More particularly, it relates to a movable apparatus containing cleaning fluids for use in cleaning the threaded portions of pipes used in oil field drilling operations.
In the oil field industry, a drilling operation involves sequentially connecting separate lengths of pipe or casing to a drilling bit fixture which is rotated by the oil drilling rig. The drill bit is pushed downwardly into the earth and a rotary motion is imparted to the drill bit by rotating the pipe or casing from an above-ground location. After the drilling rig has advanced the drilling bit vertically a given increment of length, the drilling operation may be temporarily discontinued or may be continued while an additional length of pipe or casing is positioned for engagement by the jaws of the drilling fixture. Thereupon, drilling is begun again, and this sequence continues until it is desired to cease the drilling operation.
Drilling operations often involve vertical penetrations of hundreds or even thousands or tens of thousands of feet, and such drilling requires continual additions to the great length of pipe already in use. Whether shallow or very deep well drilling is involved, it is exceptionally important that there be no leakage or weakness in the pipe joint areas. Consequently, the threads used in oil field pipe or casing are highly precise, and specially designed to insure that a strong, precisely fitted joint will be formed where two of the pipes connect.
In the conduct of oil field operations, it is common to leave the pipe or casing used in drilling in an outdoor atmosphere, inasmuch as the number of pipe lengths required in a given drilling operation is very large and indoor storage is impractical. In this connection, the pipe itself is highly weatherproof, except for the specially threaded areas in the pipe. Most if not all drilling pipe includes a male and a female end. Each end is provided with a substantial length of thread of a particular cross-section intended to provide the extremely tight seal and strong mechanical connection required in oil field drilling conditions. It is customary therefore to situate a significant supply of pipe in a given area more or less adjacent a drilling site and have it remain unprotected until the time for use approaches.
After outdoor storage and prior to use, it is necessary to expend significant effort in cleaning the threaded portions of the pipe, both male and female, as the pipes are being prepared for the interfitting process immediately preceding the drilling operation. Because of the size and weight of the pipe, particularly pipes of larger diameters, it is not practical to move the pipe to a location for cleaning and then remove the pipe from this location to still another location for short term storage or fitting to adjacent pipe sections. Therefore, it has become customary to clean pipe threads in the field.
Pipe thread cleaning operations traditionally involve the use of hand labor with solvent and brushes to clean the pipe to the degree necessary to insure formation of a satisfactory seal between adjacent pipe sections. Again, because of the size and shape of the pipe, and because of the possibility of environmental damage arising from spillage of the cleaning liquid on the ground, it has been required to position a supply of pipe cleaning liquid beneath the end of the pipe section being cleaned and to maintain it there until the next section is to be cleaned. Consequently, pipe thread cleaning is best accomplished by an apparatus which is portable so that it may be situated beneath the ends of the pipes to be cleaned.
Moreover, it is desirable to have a cleaning apparatus which may be raised or lowered so that its fluid receptacle portion may be positioned just beneath the pipe section to be cleaned. In this connection, it is desired to recover the major part of solvent resulting from the cleaning operations rather than permitting the solvent to be lost to the ground or other surrounding areas. Environmental considerations and the expense of lost cleaning liquid both strongly dictate that there be minimum spillage or solvent lost during the cleaning operation.
Referring now to the state of the art, and more particularly to solvent cleaning apparatus used in the past, one of the shortcomings commonly associated with such prior art apparatus is the inability to provide a reliable cover for the solvent reservoir. In some cases, if a lightweight removable cover is provided, it is subject to being blown off by strong winds incident to storm conditions in the oil fields. In many areas, such as the southwest portions of the United States, violent storms are a common occurrence. Consequently, lightweight, readily portable covers are not practical or desirable for a cleaning apparatus.
Accordingly, more ponderous, heavy-duty covers have been provided, but these covers have proven difficult to manipulate and, if separate from the machine, their installation after use is frequently simply forgotten or, because of their weight intentionally avoided. Consequently, a continuing strong need exists for a cleaning apparatus which includes a combination of protective means for the solvent supply receptacle as well as means for insuring that cleaning solvent is recovered from the cleaning operation and is not lost to the area surrounding the pipe ends.
SUMMARY OF THE INVENTION
Accordingly, to overcome the shortcomings in prior art devices used in cleaning pipe threads, it is an object of the present invention to provide an improved pipe thread cleaner apparatus which includes a readily positionable receptacle supported on a chassis which includes a multi-purpose flow control assembly for protecting the cleaning fluid receptacle on the one hand from rain, dust and other contaminents and which, on the other hand functions to collect cleaning fluid impinging on the flow control assembly.
It is another object of the invention to provide an apparatus which is simple in operation and rugged and reliable in use.
It is a further object of the invention to provide an apparatus wherein a simplified mechanism is provided for protecting the cleaning liquid receptacle and for collecting cleaning fluid, which forms an integral portion of the machine which may be moved between different positions of use with great simplicity and reliability.
It is still another object of the invention to provide an apparatus wherein the cleaning fluid receptacle may be positioned relative to the threaded pipes and to the chassis of the apparatus by a plurality of reliable positioners which may be adjusted independently of each other for purposes of leveling or otherwise.
It is a further object of the invention to provide an apparatus including a pair of opposed drain panels adapted to cooperate with each other to collect liquid in one position and to repel it in the other.
It is another object of the invention to provide an apparatus for pipe thread cleaning which includes a manually operable pump of simple and reliable construction.
It is a further object of the invention to provide a multi-purpose pipe thread cleaning apparatus which may be reliably left in an exterior environment which is protected from precipitation or other environmental factors damaging or diluting the supply of cleaning liquid and which minimizes the risk of adverse effects to the environment arising from the cleaning operation.
Finally, it is still another object of the invention to provide an apparatus in which the cleaning liquid may be readily removed and replaced without the necessity for moving the apparatus and without risk of damage to the environment.
In accordance with these and other objects, the invention provides a mobile apparatus for supplying and collecting cleaning fluids. The new and improved apparatus of this invention includes a chassis assembly, a receptacle assembly, means carried by the chassis for adjustably positioning the receptacle assembly and a multi-purpose assembly adapted in one position of use to cover and protect the receiving means against entry of rain or the like and in another position of use to assist in collecting cleaning fluid impinging thereon and directing it to the interior of the receptacle.
According to the invention, the requirements are able to be met in an economical and reliable manner by providing a pipe cleaner apparatus of a relatively portable nature, which includes a receptacle for cleaning liquid, a chassis, and means for positioning a receptacle near the pipe ends, as well as a multi-piece flow control assembly serving to protect the receptacle area and also to provide a collection function.
In one preferred form, the apparatus includes an adjustably positionable receptacle mounted for movement on a chassis assembly, with the receptacle including means for receiving a supply of liquid used in the thread cleaning operation. In a preferred form, the apparatus includes a multi-purpose assembly which serves, in one position, to confine and collect cleaning fluid by directing it toward the sump portion of the receptacle, and in another position, to protect the receptacle against contamination by rain, dust, or the like incident to outdoor storage and use.
In its presently preferred form, the receptacle unit includes a pair of opposed shroud elements with vertical sidewalls, and the panels making up the multi-purpose assembly are pivotally mounted units having opposed lateral edges with wiper lips to prevent passage of liquid between the panel and the sidewalls of the receptacle to prevent fluid leakage in that area.
The apparatus of the invention is suited for movement to position adjacent and beneath the ends of pipes to be cleaned, which pipes are usually stored on the outside of buildings or other protection. Thus, the cleaning apparatus may remain outside on the job site without need for external protection to keep the contents of the cleaning liquid receptacle free from water and dirt.
Other objects and advantages of this invention will be apparent from the following detailed description of the preferred embodiments of the invention taken in conjunction with the Drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the new and improved pipe thread cleaner apparatus of the present invention showing the apparatus in a raised, extended cleaning position with the flow control assembly in a fluid collecting position for directing cleaning fluids into the cleaning fluid receptacle;
FIG. 2 is an enlarged cross sectional view of the new and improved cleaning apparatus taken along view lines 2--2 of FIG. 1 and showing in phantom lines the environmentally protective position of the flow control assembly.
FIG. 3 is an exploded perspective view of the new and improved cleaning apparatus of the present invention;
FIG. 4 is an enlarged perspective view of one scissor jack assembly useful for positioning the receptacle of the new and improved cleaning apparatus of the present invention relative to the chassis and the threaded end portion of a pipe to be cleaned;
FIG. 5 is a fragmentary side elevation view of the scissor jack assembly showing the raised position of the jack assembly in phantom lines;
FIG. 6 is a fragmentary top plan view of the new and improved cleaning apparatus of the invention with portions cut away to show the panel locking mechanism for securing portions of the flow control assembly in its various positions of use;
FIG. 7 is a fragmentary elevated cross sectional view of the panel locking mechanism taken along view lines 7--7 in FIG. 6;
FIG. 8 is an enlarged fragmentary cross sectional view of the flow control assembly and panel locking mechanism taken along view lines 8--8 in FIG. 6 and showing the panels in their protective position in phantom lines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1-3, the present invention provides a new and improved mobile pipe thread cleaner apparatus generally designated by reference numeral 10. Pipe thread cleaner apparatus 10 includes a number of principal assemblies or elements, each of which may in turn be constructed from a number of other parts or components.
More particularly, apparatus 10, as shown in FIGS. 1-3, includes a chassis assembly generally designated 12, a receptacle assembly generally designated 14, and means generally designated 16 for adjustably positioning the receptacle assembly 14 relative to the chassis 12. In addition, apparatus 10 includes a multi-purpose flow control assembly, generally designated 18, and best shown in FIGS. 3 and 6-8 for serving the functions of protecting the receptacle 14 against entry of rain and particulate matter in one position of use and also, in another position of use, to aid in collecting cleaning fluid and directing it to the lowermost or sump portion of the interior of the receptacle assembly 14. In addition, a panel locking mechanism, generally designated 20, is provided to secure the various portions of the flow control assembly 18 in their respective positions of use.
Other elements of the apparatus include left and right hand receptacle frame shrouds, generally designated 22, 24 respectively, for covering upper frame portions 23, 25 of the receptacle assembly 14, and a pump assembly, generally designated at 26. In addition, the receptacle positioning assembly 16 in turn includes left and right hand scissor jack sub-assemblies 28, 30, each in turn consisting of a number of elements, to be more particularly described hereinafter.
Referring now to the construction of the various individual elements, the chassis assembly 12 is shown to include left and right hand longitudinally extending frame members 32, 34, each of which includes a pair of inwardly facing jack locator channels such as the channels 36, 38 on the frame member 34. Counterparts of the jack locator channels 36, 38 are also present on the left hand frame member 32, although they are not shown in FIG. 3. The longitudinal frame members 32, 34 are secured to each other by front and rear cross members 40, 42 shown in FIGS. 1 and 3. Four wheel support assemblies generally designated 44-47 are formed by plates extending from the respective ends of the longitudinal and cross frame members 32, 34, 40, and 42. Each wheel support assembly is substantially identical, and each includes a wheel unit 48, mounted for rotation about an axle 50 carried by a fork 52 having its upper end (not shown in detail) journaled in appropriate bearings or the like in a known manner so as to permit the fork and wheel 48, 52 to swivel in any convenient direction.
Referring now to the receptacle assembly 14, this unit is shown to include a basin unit, generally designated 54 in FIGS. 2 and 3 and shown to include a lowermost or liquid-receiving sump portion 55 (FIG. 2) defined by a pair of end walls 56, 58, a bottom wall 60, and a pair of opposed contoured sidewalls generally designated 62, 64. The sidewall 62 is shown to include an upper sidewall section 66, an intermediate, tapering wall section 68, and a lower vertical wall section 70. The sidewall 64 is made up of similar sections disposed opposite their counterparts just enumerated. Affixed to and extending outwardly from the upper edge of the upper sidewall section 66 is a slightly inclined drain board 72, having its inner end lower than its outer end so as to direct fluid impinging thereon back to the interior of the basin 54. A counterpart drainboard 74 is associated with the other sidewall 64. The upper portions of the basin end walls 56, 58, and the lateral edges of the drain boards, 72, 74 are permanently affixed to left and right hand upper frame portions 23, 25 to provide rigidity for the structure of the receptacle assembly 14 as a whole.
In addition to the elements just described, the basin 54 preferably includes an opening 76 in one of its end walls 56 for reception of the hub end of a pump crank described elsewhere herein. A pair of pull bars or handles 78 (FIG. 2) extend between the outer ends of the upper frame portions 23, 25 to assist in pulling the unit 10 from one location to another.
Referring again to FIGS. 1-3, the construction of the shrouds 22,24 for the receptacle frame is shown. While one shroud 22 is preferably larger than the other shroud 24 for purposes of extending over a portion of the pump assembly in a manner to be described, the units 22, 24 are similar in their main elements and functions, and accordingly, only the right hand unit 24 will be described in detail. This shroud 24 is shown to include a top surface portion 80, an outer sidewall 82, and an inner sidewall sealing surface 84. As shown in FIG. 3, extending inwardly from the tapered lower portions of the sidewall 84 are first and second drain panel support flanges 86, 88. These flanges 86, 88 have their axially inner edge portions 90, 92 spaced apart from each other by a short distance, for example three or four inches.
For purposes of obtaining a substantially liquid-tight seal, it is preferred that the inner sidewall sealing surfaces, such as the surface of the wall 84, be smooth and vertical.
Referring now to the multi-purpose flow control assembly 18, which acts to drain liquid either away from or toward the basin 54, this unit 18 includes opposed, first and second cooperating drain control panels generally designated 94, 96.. The panel 94 includes a down turned outer margin 98, a principal collection surface 100, and a pair of wiper lips 102, 104. At its inner end, and referring now in particular to FIG. 8, the panel 94 is shown to have a free inner edge 106, and to include therebeneath a locating channel assembly generally designated 108 having a generally U-shaped configuration and shown to include a movement-limiting lower flange 110 kept spaced apart from the edge 106 of the panel 110 by an offsetting leg 112. A similar form of engagement is provided for the other drain flow control panel 96, which is shown in FIGS. 1-2 to include an outer, turned down margin 114 terminating in a free edge 116. The panel 96 also includes wiper lips 118, 120 on opposite sides of the collection surface 122. The innermost free edge 124 of the panel 96 also includes a U-shaped locating channel generally designated 126 including a movement limiting lower flange 125 and offsetting leg 127 which cooperates with the u-shaped channel 108 on panel 94.
More particularly, and referring to FIG. 8, the innermost free edge 124 of panel 96 is received within the u-shaped locating channel 108 on panel 94. As shown therein, free edge 124 is engaged between free end 106 and movement limiting lower flange 110 on panel 94. Lower flange 125 on panel 96 is disposed adjacent the underside of lower flange 110. With this interleaving or interdigitating arrangement, the flange edge 110 is always captive within the channel 126, and the interleaved or interdigitated labyrinth formed by cooperative engagement of the locating channel assemblies 108 and 106 diverts liquid flow either away from or toward the basin 54, depending on the position of the panels 94, 96.
Alternatively, as shown in FIG. 2, free end 106 of panel 94 may be received within u-shaped locating channel 126 on panel between free edge 124 and flange 125 to provide the cooperative labyrinth structure.
Moreover, as shown in FIG. 3, outer margin 114 of flow control panel 96 may be upturned instead of downturned. Upturning the outer margins provides a collection area or trough for pooling residual fluids retained on collection surfaces 100 and 102, when the panels are moved to their raised position. More particularly, oil and tar residues may cling to collection surfaces 100 or 102 in use with the panels 94 and 96 being in their lowered collecting position. Thereafter, when the panels are raised to a protective position, the residual materials may tend to run off surfaces 100 and 102 onto the ground. By providing an upturned margin 114, as in FIG. 3, the residual materials running off of surfaces 100 and 102 may be pooled adjacent the base of the upturned margin 114 instead of running off onto the ground. The collected residues may be wiped or removed with a cloth prior to the next use of the apparatus.
Referring again to FIG. 3, the opposed outer or remote ends of the drain panels 94, 96, are arranged for pivotal movement about the respective axes of a pair of spaced apart hinge rods 130, 132. These hinge rods 130, 132 extend through appropriately positioned openings in the upper frames 23 and 25, including the openings 134, 136 in the upper receptacle frame portion 25. In the preferred form of apparatus, the pivot rods 130, 132 extend through openings in aligned and opposing pairs of hinge ears 138, 140 (two only shown in FIG. 3) extending downwardly from the under-surface of the drain panels 94, 96. With the panels 94, 96, thus located for movement of their proximate ends through an arc between the open and closed positions shown in the respective broken and solid line positions of FIGS. and 8, liquid impinging on the upper panel surfaces 100, 122 will be directed toward the interior of the basin 54 or outwardly of the remote edges of the panels adjacent the outer ends of apparatus 10.
Control of movement between the open and closed positions is achieved by the provision of a panel locking mechanism, generally designated 20, and shown to include a locking handle generally designated 142, which includes a gripping portion 144 and a lower shank 146. The handle is secured by a cotter pin and washer arrangement designated 148 to a rotatable locking bar carrier 150, which includes openings 152, 154 for receiving the turned down end portions of locking bars 156, 158, respectively. The outer ends of the bars 156, 158 pass through locating ears 160, 162 depending from the lower surface of panel 96 as shown in FIGS. 6-7. Rotation of the handle in a ninety degree clockwise direction causes the free ends 164, 166 of bars 156 and 158 to move laterally outwardly within locating ears 160 to an extended position. Accordingly, drain control panels 94 and 96 may be moved to their raised protective position by lifting handle grip 144 and rotating it clockwise to permit free ends 164, 166 of bars 156, 158 to restingly and supportedly become engaged on the drain panel support flanges 88, as shown in the dotted line position in FIG. 7. Simply returning the handle to the position of FIG. 6 releases the rod ends 164, 166 from engagement and allows the panels to fall into a lowered position, wherein their under-surfaces are respectively supported by the upper surfaces of the drain panel support flanges 86, 88. The interleaving action of the channels 108, 126 provides a cooperative interdigitated or labyrinth seal for eliminating or minimizing liquid flow of undesirable rain water or the like into the solvent located in sump portion 55. Wiper lips 102, 104 and their counterparts achieve the same purpose of aiding in flow control.
Referring now in particular to FIGS. 4 and 5, constructional details of the left and right hand scissor jack subassemblies 28, 30 are shown; FIGS. 4 and 5 show one such assembly 28. The principle of the assembly is known to those skilled in the art. In the preferred form shown, not only is the left hand subassembly 28 identical to its counterpart 30, but the right hand side elements of the subassembly 28 are substantially identical to their left hand counterparts. Consequently, the construction of only one side is described in detail, it being understood that the remainder of the mechanism includes elements such as spacers to retain the alignment of counterpart elements to facilitate operation of the screw thread mechanism which is positioned in the centers. Thus, the right hand side of the subassembly 28 includes first and second lower legs 170, 172 and first or shorter and second (or longer) upper legs 174, 176.
The first lower leg 170 includes a fixed end, through which a hinge rod 178 extends. The end on the hinge rod is received in an opening (not shown) in the longitudinal frame member 32. Thus, the lower end of the first lower leg 170 may pivot about the axis of the rod 178 but does not move in a left-to-right sense. The lower end of the second lower leg 172 is pivotally joined to a slide block 180 which is received in use within a jack locator channel (such as channel 36) in the frame member 34. The lower end of the second leg 172 will then move from right to left in use, as will appear. A center pivot 182 joins the lower legs 170, 172 at an intermediate point, and a pair of end pivots 184, 186 are provided to link the upper ends of the lower legs 170, 172 to the lower ends of the upper legs 174, 176. These legs are pivotally secured to each other by a pivotable coupling 188.
The upper end of the upper long leg 176 terminates in a mounting ear 190 for an upper slide block 192. This slide block is positioned for reciprocation relative to and as an associated part of the upper frame 23 of the receptacle assembly 14. As shown, various tie rods 178, 196, 198, 200 extend between pivot points of the mechanism. Further, welded-in spacers 202, 204 also maintain the legs of the scissor assembly in a fixed relation to their counterparts to insure parallel operation.
Each of the larger diameter tie rods 198, 200 includes an enlarged diameter center sleeve section 206, 207 having an opening for the passage of a threaded elevator rod 208. One end of the elevator rod 208 includes a locking collar 210 and a hand crank 214. The other end includes an end stop 216 so that the threaded elevator rod 208 is permitted to rotate but not move axially with respect to the sleeve 206. Rotation of the threaded rod will cause the sleeve sections 204, 206 to move together or apart, thus moving the pivot points 184, 186 together or apart. Moving pivot points 184, 186 together causes movement of the lower slide block 180 relative to the end of the hinge rod 178, causing the linkage as a whole to assume a more or less upright position.
Referring now to FIGS. 2-3, there is shown another optional component which is preferred for use with the apparatus of the invention, namely, a liquid pump assembly generally designated 26. Pump assembly 26 includes a pump 220 which is preferably a manually operated pump of the positive displacement type, having an exterior housing 222, a stand 224, and a rotatable stub drive shaft 226 extending out from the end wall 228 of the housing 222. A pump crank shaft extender 240 extends through the opening 238 in the receptacle sidewall 70 to a free end on which a detachable hand crank 230 may be removably positioned. The pump unit is preferably arranged with its outlet in fluid communication with a hose 232 having an outlet nozzle 234 affixed to the end thereof.
In a preferred embodiment, a locking type shutoff valve assembly 236 with an outlet or drain hose 242 may be provided in the lower vertical sidewall 70 of the receptacle 12, as shown in FIGS. 2 & 3.
In use, the hand crank 230 operates the pump 220 to direct a supply of cleaning liquid through the hose 232 and nozzle 234 toward the pipes to be cleaned, so that the cleaning liquid may be used repeatedly. When the solvent is exhausted or contaminated, then it may be removed to a portable disposal container cranking the pump unit 220 for this purpose, or by opening valve 236 to hose 242 to drain the receptacle 12. Alternatively, an electrically operated or air operated pump might also be used, but since the apparatus 10 is primarily intended for outdoor use remote from available power, the manually operated cranking pump system such as 220 has proven satisfactory.
Referring now to a typical use of the apparatus, apparatus 10 is typically stored with the receptacle in its lowered or retracted position and with the panels 94, 96 in the raised position of use as shown in FIGS. 2 and 8. When it is desired to transport the unit to the work site, the user grasps the handle 78 and rolls apparatus 10 to a position of use, pulling the chassis and the remainder of the unit to a location adjacent the threaded end of a pipe to be cleaned. The swivel mounted wheels enable the unit to be moved and positioned adjacent the work with flexibility and simplicity. Once in position of use, the flow control panels 94, 96 are lowered to the solid line position of FIGS. 2 and 8 by rotating the handle 142 which releases the locking bars 156, 158 and permits the panels to rest on the drain panel support flanges 86, 88. Thereupon, the washing operation commences and whatever fluid is drained from the work site is collected on the panels and directed to the area adjacent the proximate ends of the panels, as shown in FIG. 8. In this connection, inasmuch as the liquid is intended to flow in the space between panels, the channels, such as the channels 108, 126 are adapted to permit fluid flow therebetween in their lowered collecting position. A slight gap of perhaps about three-eights of an inch to permit liquid flow between the panels may be provided. The liquid is thus directed to the sump area 55 at the bottom of the basin unit 54 for continued re-use.
Positioning the receptacle assembly 14 as a whole is achieved by manipulating the respective hand cranks 214, so that the scissor jacks place the receptacle 14 closely underneath the work to minimize splashing and other loss of cleaning liquid. During this phase of the operation, the pump crank 230 may be operated so as to direct solvent to the work site.
After the cleaning operation has been performed, and it is desired to leave the apparatus for a period of time in outdoor storage, it is only necessary to manipulate the locking assembly 20 by grasping the gripping portion 144 of the handle 142, raising the flow control assembly and rotating the handle to the locked position. After the panels 94, 96 are raised to the phantom line position of FIG. 8, the handle 142 is rotated clockwise so that the bar ends 164, 166 of the locking bars 156, 158 are received on support flanges 88, thereby locking the panels 94, 96 in their protective covering position over the sump 55. In this manner, rain and wind-borne debris will be excluded from the cleaning liquid.
According to the invention, the cleaning equipment may be moved adjacent the work site with great convenience. The environmental damage due to spillage is prevented because the pump assembly permits disposition of the used solvent into portable containers, and because the arrangement of drain panels provides an effective way to recover solvent.
The present invention provides a new and improved all weather apparatus for cleaning pipe threads having a number of novel advantages and characteristics, including those referred to specifically herein and others which are inherent in the invention. Although the present invention has been described with reference to a preferred embodiment, modifications or changes may be made therein by those skilled in this art. For example, instead of a manually operated positive displacement fluid pump, other pumping means may be used. Moreover, instead of the scissor jack assemblies, other means for raising and lowering the receptacle assembly with respect to the chassis including mechanical, pneumatic or electrical may be substituted. All such obvious modifications or changes may be made herein by those skilled in this art without departing from the scope and spirit of this invention as defined in the appended claims.
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A mobile apparatus for supply and collection of cleaning fluids used in field cleaning of pipe threads preparatory to oil field drilling operations is described. The apparatus includes a moveable cart structure defined by a chassis with wheels. An upper frame member is connected to the chassis by a plurality of scissor jack assemblies which may be independently extended or contracted to raise and lower the upper frame with respect to the chassis. A basin for receiving pipe thread cleaning solution is affixed to the movable upper frame member and depends therefrom. A flow control cover including a pair of pivotable panels interleaved at their inner ends over the central portion of the basin is provided to substantially cover the basin. The panels are movable to an inwardly sloping position to collect and funnel cleaning fluid back into the basin for periods of active use. The panels may also be moved to a raised sloping position to provide a protective roofing cover to prevent ingress of environmental moisture or particulates into the basin. Shrouding elements may be secured to the upper frame to provide water tight seams along the sides of the flow control panels. A hose and pump assembly may be included to withdraw fluid from the basin for use or to remove spent fluids. The apparatus includes features which permit it to be stored out of doors in the field without risk of contamination to or from the environment.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/629,252 for “SAW Ladder Filter” having filing date Nov. 18, 2004, the disclosure of which is incorporated herein by reference in its entirety, all being commonly owned.
FIELD OF INVENTION
[0002] The present invention generally relates to surface acoustic wave (SAW) devices, and particularly to a SAW device exhibiting improved electrostatic discharge (ESD) characteristics.
BACKGROUND
[0003] SAW devices are widely used in communication systems. The small size, low cost and ease of high-volume manufacturing lend SAW devices to be readily adapted for mobile phones. A number of SAW devices are used as front-end filters, which are either connected to the antenna of mobile telephones or are placed very close to the antenna. These SAW devices are duplexers and triplexers. The SAW duplexer includes a dual SAW bandpass filter which enables the communication system to perform concurrent reception and transmission of the signal. The triplexer is used for the reception and separation of the incoming signals into three separated frequency components. The SAW triplexer comprises a low-pass filter network for the reception and separation of the incoming signal in a low frequency band, a high-pass network to separate the signal into a high frequency band, and a SAW bandpass filter for the reception and separation of the incoming signal at a frequency band located between that of the low and high bands of the signal.
[0004] A SAW ladder filter configuration, because of its low loss and great power handling capability, is commonly used for the implementation of SAW duplexer and triplexer. One example of a SAW ladder configuration is disclosed in U.S. Pat. RE37, 375 to Satoh et al.
[0005] SAW devices such as duplexers and triplexers being used for front end filtering are highly sensitive to electrostatic discharge (ESD). ESD damage is usually caused by one of three events including a direct electrostatic discharge to the device, electrostatic discharge from the device to other components in the circuit, or it may result from field-induced discharge. In mobile phone applications, common ESD failure results from direct electrostatic discharge from a human body. There is generally a significant amount of charge build up in a human body through mechanical motion like walking across a carpet floor. The ESD voltage in the human body is then discharged across the phone electronic circuitry, when one grabs the phone touching the antenna. The ability of the device to dissipate the energy of the discharge or the ability to withstand the high voltage level is a measurement of the device ESD handling capability. Typically, for a mobile phone system, the SAW ESD handling capability must withstand a voltage peak of 8 kV contact discharge. While 8 kV is acceptable for mobile phone applications, it is desirable among several phone manufacturers to have the SAW device able to handle a voltage discharge in excess of 10 kV.
SUMMARY
[0006] A SAW filter in keeping with the teachings of the present invention may comprise a first SAW resonator element provided in a series branch of the SAW filter and a second SAW resonator element provided in a parallel branch of the SAW filter, wherein the first and second SAW resonator elements form a ladder filter network having an input signal terminal and an output signal terminal, and at least two parallel connected third and fourth SAW resonator elements provided in the series branch of the SAW filter and connected to at least one of the input and the output terminals. Each SAW resonator element may comprise a SAW transducer carried on a piezoelectric substrate surface between opposing reflectors. The SAW transducer and the opposing reflectors generally include a plurality of metal electrodes disposed on the substrate surface. Each of the metal electrodes may comprise aluminum or an aluminum alloy material. Further, the metal electrodes may comprise a uniform thickness ranging from 5% to 12% of a wavelength of a propagated SAW. Each of the third and fourth SAW resonator elements may have the same transducer length and aperture width.
[0007] The pair of parallel resonator elements at the input terminal of the SAW ladder filter effectively provides a dual path for current drain thereby reducing the current density across the SAW transducer and effectively adding improved ESD protection for the filter. Further, the SAW filter may be employed in a SAW triplexer comprising an ESD protection circuitry to further enhance the ESD voltage handling capability. The ESD circuitry may include a diode or a varistor.
[0008] An embodiment employing the SAW filter may include a SAW triplexer that receives signals in at least three frequency bands and output the signal components to its appropriate signal processing ports. The triplexer may comprise a low pass filter connected to an input terminal for reception and separation of an incoming signal of a low frequency band of interest, a high pass filter connected to the input terminal for the reception and separation of the incoming signal of the highest frequency band of interest, and a SAW bandpass filter. The SAW bandpass filter may comprise series and parallel branch resonator elements forming a ladder filter configuration connected to the input terminal for the reception and separation of the incoming signal at the frequency band located between the low and the high bands of the signal, and the input terminal connected to an ESD protection circuitry comprising at least one of a diode and varistor. Yet further, the SAW triplexer may include the resonator element comprised of SAW transducer and reflectors having metal electrodes disposed upon a piezoelectric substrate. The input terminal may be connected to a series branch resonator element comprising of at least two parallel-connected resonators.
BRIEF DESCRIPTION OF DRAWINGS
[0009] Embodiments of the invention are described, by way of example, with reference to the accompanying drawings in which:
[0010] FIG. 1 is a partial schematic layout of a SAW ladder filter in keeping with the teachings of the present invention;
[0011] FIGS. 2 and 2 A illustrate a SAW single transducer disposed between reflectors as a SAW single pole resonator manufactured layout structure, and an equivalent circuit representation, respectively;
[0012] FIG. 3 illustrates a SAW ladder filter configuration including series cascaded resonator elements provided in a series branch and a parallel pair provided in a parallel branch thereof;
[0013] FIG. 4 is a partial schematic illustrating an ESD test setup;
[0014] FIG. 5 is a schematic layout of one known SAW ladder filter illustrating resonator elements arranged in a series branch and a parallel branch;
[0015] FIG. 6 is a partial schematic view of a SAW triplexer having ESD protection according to the teachings of the present invention;
[0016] FIG. 7 is a partial schematic view of a SAW triplexer having a varistor ESD protection according to the teachings of the present invention; and
[0017] FIG. 8 is a table illustrating SAW ESD performance data.
DETAILED DESCRIPTION OF EMBODIMENTS
[0018] The present invention will now be described more fully with reference to the accompanying drawings in which alternate embodiments of the invention are shown and described. It is to be understood that the invention may be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these embodiments are provided so that this disclosure may be thorough and complete, and will convey the scope of the invention to those skilled in the art.
[0019] With reference initially to FIG. 1 , one embodiment of the present invention, as herein described by way of example, includes a SAW filter 10 including a first SAW resonator element 12 provided in a series branch 14 of the SAW filter and a second SAW resonator element 16 provided in a parallel branch 18 of the SAW filter, wherein the first and second SAW resonator elements form a ladder filter network having an input signal terminal 20 and an output signal terminal 22 . For the embodiment herein described by way of example, at least two parallel connected third and fourth SAW resonator elements 24 , 26 are provided in the series branch 14 of the SAW filter 10 and connected to the input terminal 20 , as herein described by way of example, or alternatively at the output terminal 22 .
[0020] With reference to FIG. 2 , and as herein described, each SAW resonator element 12 , 16 , 24 , 26 may comprise a SAW transducer 28 carried on a piezoelectric substrate 30 between opposing reflectors 32 , 34 . The SAW transducer 28 and the opposing reflectors 32 , 34 include a plurality of metal electrodes 36 , 38 respectively disposed on a surface of the substrate 30 . Each of the metal electrodes may comprise aluminum or an aluminum alloy material. In addition, one embodiment of the invention herein described and tested includes metal electrodes having a uniform thickness ranging from 5% to 12% of a wavelength of a propagated SAW. Yet further, each of the third and fourth SAW resonator elements 24 , 26 may have the same transducer length 28 L and aperture width 28 W. The commonly used piezoelectric substrates are lithium tantalate and lithium niobate.
[0021] By way of example and with reference to FIG. 3 , a SAW ladder filter 40 may include multiple series resonator elements 42 , as above described with reference to FIG. 1 as the first SAW resonator element 12 configured in a series cascaded of two resonator elements 44 . The cascaded resonator elements 44 may have an aperture twice as large as the single resonator element 12 thereby providing an equivalent capacitance. The series cascaded resonator elements 44 enhance heat absorption and dissipation, and thus improve power-handling capability of the SAW device. As illustrated with continued reference to FIG. 3 , a parallel SAW resonator element 46 may also be arranged in as a parallel pair of resonator elements 48 .
[0022] As above described, a SAW ESD handling capability for a mobile telephone must typically withstand a voltage peak of 8 kV contact discharge. While 8 kV is acceptable for mobile phone applications, it is desirable among several phone manufacturers to have the SAW device able to handle a voltage discharge in excess of 10 kV. By way of example, and with reference to FIG. 4 , one ESD test set up 50 used to test whether the SAW device 10 in a triplexer can withstand an 8 kV discharge is illustrated. The capacitor (C) is charged by the voltage source (V) by closing a first switch (S 1 ) until the capacitor (C) reaches 8 kV. Switch (S 1 ) is then opened. A probe is then allowed to touch an antenna of a phone carrying the SAW filter 10 and a second switch (S 2 ) is then closed to discharge the high voltage across the device having the SAW filter. By way of example with regard to typical ladder filters as illustrated with reference to FIG. 5 , the triplexer being tested that uses the typical SAW configuration 52 consistently failed. Failure analysis on SAW triplexers indicates that damage is at the SAW input series resonator element 54 . The damage to the SAW filter 52 generally results from a relatively large current spike draining through the SAW transducer in very short time duration. The ESD damage can cause catastrophic failure to the SAW device by melting some of the electrode fingers 56 of the SAW transducer or by blowing a hole in the piezoelectric substrate 30 , as illustrated with reference again to FIG. 2 .
[0023] Embodiments of the present invention, as above described with reference to FIGS. 1 and 3 by way of example, provide SAW ladder filter embodiments that can absorb and withstand a higher than normal ESD voltage. Further, solutions for allowing a SAW triplexer to handle greater ESD voltage discharge will also be described herein by way of example.
[0024] With reference again to FIGS. 1 and 2 , the resonator elements 12 , 16 may be also described in an equivalent lumped element circuit as illustrated with reference to FIG. 2A . Co represents an electrostatic capacitance while Cm and Lm represent an equivalent motional element of the resonator. Ignoring the resistance of the resonator, the equivalent combinations of these elements provide a good estimate of the resonator impedance. With reference again to FIG. 1 , the parallel element pair 24 , 26 at the input terminal 20 of the SAW ladder filter 10 is a series element. Each resonator element 24 , 26 of the parallel pair of elements in the series branch has approximately the same impedance for the embodiment herein described, which implies that the transducer length and aperture of each resonator element of the resonator pair is approximately the same. With an ESD voltage discharge, the parallel resonator elements 24 , 26 at the input series branch of the SAW ladder filter 10 provide a dual current path such that the current density across the each resonator is reduced approximately by half, thereby enhancing the ESD handling capability. The parallel resonator pairs incorporated at the input series element of the SAW ladder filter thus operate as a current divider. As above described, one embodiment includes the transducer lengths 28 L and aperture widths 28 W of the parallel resonator pair are as close as practically possible to each other. However, it has been shown that a 25% difference in transducer length or aperture would still provide an adequate improvement in the handling of ESD. The SAW ladder filter 10 may be connected directly to an antenna, indirectly through a matching network of inductors and capacitors, or through an ESD protection circuitry. The protection circuitry may comprise a diode or a varistor, by way of example. The ESD protection circuitry would enable the SAW device to withstand additional ESD voltage discharge.
[0025] A SAW ladder filter configuration, because of its low loss and great power handling capability, is effectively used for the implementation of SAW duplexers and triplexers. With reference now to FIG. 6 , one embodiment of the present invention may include the SAW filter 10 employed with a triplexer 58 having a low pass filter network 60 , a high pass filter network 62 , and the SAW filter 10 operating as a SAW bandpass filter. The low pass filter network 60 may include L-C components and performs the function of receiving and separation of incoming signal with the lowest desired frequency band. The high pass filter network 62 also includes L-C components and performs the function of receiving and separation of incoming signal with the highest desired frequency band. One triplexer may be as described in U.S. patent application Ser. No. 10/950,958, the disclosure of which in herein incorporated by reference. The SAW filter 10 provides the reception and separation of the incoming signal at a frequency band located between that of the low and the high bands of the signal. The triplexer 58 may be connected to an ESD protection circuit 64 , which may comprise a diode 66 or a varistor 68 as illustrated with reference again to FIG. 6 , and to FIG. 7 . The diode 66 or the varistor 68 may be connected directly or indirectly to a ground node 70 . An inductor 72 may be added to rematch any distortion of the triplexer 58 due to addition of the diode or varistor.
[0026] By way of further example, FIG. 3 includes a table illustrating test results covering prior art SAW ladder filter 52 such as that described with reference to FIG. 5 , and the SAW ladder filter 10 in which the input series element comprises two parallel resonators, as disclosed, while it is to be understood that more than two may be employed. The two filters 10 , 52 are tested under conditions with and without the ESD protection circuit 64 . The prior art SAW filter 52 fails to withstand a ESD voltage greater than 7 kV while the present invention can survive an ESD voltage up to 12 kV. With the application of the use of a diode or a varistor as an ESD protection circuit, as illustrated by way of example with reference again to FIGS. 6 and 7 , the SAW triplexer 58 can withstand the ESD voltage of greater than 16 kV. It is quite clear from the ESD performance data as presented in FIG. 8 that the parallel connection of the dual resonators shows a significant improvement over the regular series single resonator element.
[0027] Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings and photos. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and alternate embodiments are intended to be included within the scope of the claims supported by this specification.
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A SAW filter useful in cellular telephone communications includes SAW resonator elements provided in a series and parallel branches for forming a ladder filter network, and SAW resonator elements connected in parallel and provided in the series branch of the SAW filter for providing improved ESD protection to the SAW filter. The SAW filter is effectively used with an ESD protection circuit and a triplexer for receiving and separating low, high, and bandpass frequencies.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet head and an ink jet printer for printing images on a recording sheet by ejection ink droplets from nozzles in the ink jet head.
2. Description of the Related Art
In recent years, ink jet printers have been drawing attention because of their high speed, high print quality, and comparatively simple configuration. Ink jet heads are formed with ink channels filled with ink and nozzles fluidly connecting the ink channels with the atmosphere. In one type of ink jet head, the volume in selected ink channels is rapidly decreased to eject an ink droplet from a corresponding nozzle. When the volume in the ink channels increases to its original size, ink is drawn into the ink channels from a ink introduction port, which fluidly connects the ink channel with an ink supply portion.
In order to produce an ink jet head capable of printing in full color, a plurality of heads, one for each different color of ink to be ejected, is provided together in a single head. To produce a more compact printer, the ink jet head needs to be produced in a small size with a high density. U.S. Pat. No. 4, 216,477 describes two ink jet heads formed integrally together from a single common covering plate and two base plates sandwiching the common covering plate. A plurality of ink channels, or pump chambers, and a common ink reservoir in fluid connection with the ink channels are formed in each of the base plates. Electrostrictive elements are provided in the ink channels. Ink from a supply pipe is supplied to the ink channels through the ink reservoir.
SUMMARY OF THE INVENTION
However, because both the ink channels and the ink reservoirs are formed in the base plates, processes for forming the channels and the ink reservoirs in the base plates need to be precisely performed and are therefore difficult.
To overcome the above-described problem, it is conceivable to further provide a separate manifold member, made from a resin or similar material, for fluidly connecting the ink channels with an ink supply portion.
This conceivable example will be described while referring FIGS. 1 and 2. FIG. 1 is a perspective view of a conceivable ink jet head. FIG. 2 is a cross-sectional view of the conceivable ink jet head. Two actuator plates 104, 105 are formed with channel groups 102, 103 respectively. The actuator plates 104, 105 are connected to opposite sides of a single plate member 101 so that front and rear ends of the actuator plates 104, 105 and the plate member 101 are in alignment with each other. A nozzle plate 206 formed with nozzles from which ink droplets are ejected is connected to the front ends of the actuator plates 104, 105 and the plate member 101. A manifold member 108 formed with ink channels 106, 107 for bringing the channel groups 102, 103 respectively into fluid connection with an ink supply portion (not shown in the drawings) is connected to the rear ends of the actuator plates 104, 105 and the plate member 101. With this configuration, the open rear ends of the channel group 102, 103 open into -the ink channels 106, 107 respectively. Adhesive for attaching the manifold member 108 to the actuator plates 104, 105 is coated to the rear end surface in the actuator plates 104, 105 and to a front end surface 109 of the manifold member 108. A silicone rubber that hardens at room temperature could be used as the adhesive.
However, with this conceivable configuration, the front end surface of the manifold member 108 and corresponding rear surfaces of the actuator plates 104, 105 to be adhered together must be extremely flat. If not, then spaces can be formed at the adhered surfaces or possibly adhesive can flow into the ink channels. It is difficult to obtain surfaces flat enough to prevent these problems. If spaces are formed between the channel groups 102 and 103, then different colors of ink will be mixed into adjacent ink channels. It is imperative that different colors of ink not be mixed and ejected together, but that the different colors of ink be ejected separately after the portion attached by adhesive has hardened.
It is an objective of the present invention to overcome the above-described problems and to provide an ink jet head and an ink jet printer with a simple, compact and easy-to-produce configuration and capable of high density recording in full color without different colored inks mixing together.
In order to achieve the above-described objectives, an ink jet head according to the present invention includes: a plate member having left and right sides opposite each other, a front end and a rear end opposite each other, and a length from its front end to its rear end; two substrates each having a front end and a rear end opposite each other and a length from its front end to its rear end shorter than the length of the plate member, each substrate being attached to one of the left and right sides of the plate member so that the substrates sandwich the plate member therebetween and the rear end of the plate member protrudes beyond the rear ends of the substrates, each substrate being formed with a channel group including a plurality of ink-ejection channels extending from its front end to its rear end; and a manifold portion attached to the rear ends of the substrates and to left and right sides of the protruding rear end of the plate member and formed with two ink-supply channels each in fluid connection with the channels of a corresponding one of the channel groups.
With this configuration, a head having nozzles for ejecting a plurality colors of ink can be obtained in a single assembled head. The single assembled head has a compact shape and high nozzle density. Further, adjacent channels are completely separated. Because the portion where adhesive is coated to connect the manifold member is not in direct contact with any ink channel, even if the connection of the manifold member is slightly imprecise, adjacent channels will remain separate and unconnected so that different colors of ink can be prevented from mixing together.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the invention will become more apparent from reading the following description of the preferred embodiment taken in connection with the accompanying drawings in which:
FIG. 1 is an exploded view showing a conceivable print head;
FIG. 2 is cross-sectional view showing the conceivable print head;
FIG. 3 is a perspective view showing an ink jet printer with a print head according to a first embodiment of the present invention;
FIG. 4 is a perspective view showing the print head;
FIG. 5 is an exploded view showing the print head;
FIG. 6 is a cross-sectional view showing the print head;
FIG. 7 is a cross-sectional view showing a print head according to a second embodiment of the present invention.
FIG. 8 is a cross-sectional view showing drive electrodes in ink channels; and
FIG. 9 is a cross-sectional view showing the mounting for a heat generating resistor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An ink jet head and an ink jet printer according to a first embodiment of the present invention will be described while referring to the accompanying drawings wherein like parts and components are designated by the same reference numerals to avoid duplicating description. It should be noted that the terms front, rear, right, and left refer to directions indicated by thus-labeled arrows in the drawings.
FIG. 3 is a perspective view schematically showing a color ink jet printer according to the present embodiment. The color ink jet printer 1 includes an ink jet head 2 capable of ejecting four colors of ink (i.e., cyan, magenta, yellow, and black) onto a recording sheet such as a print sheet P; a head unit 4 provided integrally with the print head 2, an ink cartridge 5 provided on the head unit 4 for supplying four colors of ink to the print head 2, and a carriage 3 provided for supporting the print head 2 and on which the head unit 4 and the ink cartridge 5 are freely detachably mounted.
As will be described in further detail later, the print head 2 is provided with piezoelectric ceramic elements, which serve as energy-generating elements for generating energy to eject droplets of ink. When a voltage is applied to the piezoelectric ceramic elements, they deform in a pumping action which is used to eject ink droplets for printing characters and symbols on the print sheet P. It should be noted that the print head 2 can be replaced with a thermal head which uses thermal-electric elements instead of piezoelectric elements.
A carriage shaft 7 is supported on a frame of a housing 1a of the ink jet printer 1. A carriage shaft support portion 3a provided to the underside of the carriage 3 is mounted on the carriage shaft 7 so that the carriage 3 is reciprocally and linearly movable in a direction indicated by an arrow B in FIG. 3. An idle pulley 8 and a drive pulley 9 are provided at either end of the housing 1a. A belt 10 connected to the carriage 3 is suspended between the pulleys 8 and 9. When a motor 11 provided for driving the pulley 9 drives the pulley 9 to rotate, the carriage 3 is driven to move linearly and reciprocally along the carriage shaft 7. A freely rotatable platen roller 6 is provided in opposition to the front surface of the print head 2 in parallel with the carriage shaft 7. The print head 2 and the platen roller 6 form a print portion.
Although not shown in the drawings, a sheet supply cassette is provided to the upper-rear portion of the ink jet printer 1. The sheet supply cassette 1 transports a print sheet P in a direction indicated by an arrow C in FIG. 3. The platen roller 6 is driven to rotate in a direction indicated by an arrow A so that the print sheet P is transported between the print head 2 and the platen roller 6. After printing is completed, the print sheet P is discharged in a direction indicated by an arrow D. As they do not deal directly with the invention, components for supplying and transporting the print sheet P have been omitted from the drawings.
During operation of the ink jet print head 2, bubbles are generated within the print head 2. Also ink droplets can cling to the surface of the nozzle plate of the print head 2. This can result in defective ejection of ink droplets. A head cleaning member 12 such as a wiper for cleaning the print head 2 is provided at the side of the platen roller 6. A purge unit 13 for preventing such defective ejections and for returning to the print head 2 to a proper operating condition is provided at the side of the platen roller 6 in confrontation with the front side of a reset condition position of the print head 2. The purge unit 13 is capable of reciprocally moving in directions indicated by an arrow E. A cap 14 is provided to the tip of the purge unit 13. During purge operations, the purge unit 13 moves toward the print head 2 so that the cap 14 is brought into abutment with the print head 2 to cover the print head 2. A pump 15 generates a negative pressure within the cap 14 so that defective ink within the print head 2 is suctioned out of the nozzles and through pipes 16, 17. This cleans bubbles and other undesirable material from the nozzles and returns the print head 2 to proper operating condition. Suctioned defective ink is deposited in an accumulation tank 18.
FIG. 4 is a perspective view showing the print head 2 according to the first embodiment of the present invention. FIG. 5 is an exploded perspective view showing the print head shown in FIG. 4. FIG. 6 is a cross-sectional view showing the print head 2 of FIG. 4. The print head 2 is for ejecting two colors of ink. The head unit 4 includes two of these print heads 2 in alignment with each other. The print head 2 includes a plate member 23; and two substrates 21, 22, one attached to either side of the plate member 23 so that front surfaces of the plate member 23 and the two substrates 21, 22 are aligned flush with each other. Ink ejection channel groups 24, 25 are formed in the substrates 21, 22 respectively. Each channel group 24, 25 is formed with a plurality of ink channels. A nozzle plate 26 formed with nozzles from which ink droplets are ejected is attached to the aligned front surfaces of the substrates 21, 22. Manifold members 29, 30 formed from a resin or other appropriate material are connected to rear surfaces 21a, 22a of the substrates 21, 22. The manifolds 29, 30 are formed at their front ends with ink-supply channels 27, 28 and at their rear ends with ink-introduction ports 27a, 28a, which are fluidly connected with the ink-supply channels 27, 28 respectively. The manifold members 29, 30 bring the channel groups 24, 25 respectively into fluid communication with corresponding ones of the ink cartridges 5a through 5d, which serve as ink supply portions.
The plate member 23 extends beyond the rear surfaces 21a, 21b of the substrates 21, 22, thereby forming an protruding portion 23a. Opposite side surfaces 23b, 23c of the protruding portion 23a and the rear surfaces 21a, 21b of the substrates 21, 22 form therebetween corner portions C. The channel groups 24, 25 are brought into fluid communication with the ink-supply channels 27, 28 at corresponding corner portions C. The manifold members 29, 30 are adhered to the corner portion C using an adhesive applied to edges of the rear surfaces 21a, 22a and the side surfaces 23b, 23c and separated from the channel groups 24, 25 and from the ink-supply channels 27, 28. Then the manifold members 29, 30 are sealed using silicone rubber and the like at sealing areas 33 shown in FIG. 4 and 6.
It should be noted that the substrates 21, 22 include a plurality of partition walls forming the ink channels 24, 25, a portion of each partition wall being formed from polarized piezoelectric ceramic elements; and a plurality of electrodes formed to the partition walls at the piezoelectric elements and which when energized generate a drive electrical field orthogonal with the direction of polarization of the piezoelectric elements. The partition walls and electrodes serve together as energy-generating elements. Possible configurations of the substrates 21, 22 are described, for example, in U.S. Pat. Nos. 5,016,028 and 5,421,071, the disclosure of which is hereby incorporated by reference.
Referring to FIG. 8, drive electrodes 324, 325 are shown formed in the apertures of ink channels 24, 25 along inner surfaces of the ink channels 24, 25. The drive electrodes 324, 325 can be formed over part of or the entire inner surface of each of the ink channels 24, 25 by vapor deposition using metallic materials such aluminum, nickel or the like. Drive electrodes 324, 325 form energy-generating elements within each of the ink channels.
Next, an explanation will be provided for operation of the print head 2 configured as described above. As mentioned previously, a pair of integrally formed print heads 2 each having two channel groups 24, 25 are provided in the ink jet printer 1. The ink-introduction ports 27a, 28a of the manifold members 29, 30 are each connected to a color ink cartridge 5. Colored ink passes through the ink-supply channels 27, 28 and is supplied to the channel groups 24, 25 of the print head 2. The piezoelectric ceramic elements provided in the substrates 21, 22 are driven based on print information from an external source. As a result, the volume of corresponding channels of the channel groups 24, 25 changes resulting in a pumping operation which ejects ink from the interior of desired channels of the channel groups 24, 25 through corresponding nozzles. Ink droplets ejected in this manner impinge on a print sheet P supplied to a position in confrontation with the print head 2 so that a full-color image can be printed.
In this way, the protruding portion 23a of the plate member 23 in the print head 2 completely separates the channel groups 24, 25 from each other. Also, the sealing areas 33 for preventing ink leaks do not directly contact the ink channels at any position. Therefore, even if the manifold members 29, 30 are attached to the substrates 21, 22 using adhesive with poor precision the channel groups 24, 25 and the ink-supply channels 27, 28, which are for transporting different colored inks, will not become fluidly connected. As a result, different colored inks will not be mixed together so that full color printing will be possible with complete division of different ink colors.
FIG. 7 is a cross-sectional view of a print head 2 according to a second embodiment of the present invention. Although the print head 1 of the first embodiment is configured with the manifold members 29, 30 connected so that the ink-supply channels 27, 28 extend in a direction substantially in parallel with the direction in which the channel groups 24, 25 extend, that is, parallel to the direction from the front to the rear of the substrates 21, 22, in the second embodiment, manifold members 129, 130 are attached so that ink-supply channels 127, 128 extend in a direction substantially perpendicular to the direction in which the channel groups 24, 25 extend. Because the plate member 23 of the second embodiment also includes the protruding portion 23a, the channel groups 24, 25 are completely separated from each other. Further, sealing areas 33 are not in direct contact with the channels of the channel groups 24, 25 so that the same good effects of the print head 1 of the first embodiment can be achieved.
As is clear from the above-described embodiments, by providing the protruding portion 23a to the plate member 23, the ink-supply channels 27, 28 can be freely designed either perpendicular to or parallel with the direction in which the channel groups 24, 25 extend.
While the invention has been described in detail with reference to specific embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the attached claims.
For example, although the above-described embodiments disclose an ink jet head having piezoelectric ceramic elements provided to the substrates 21, 22, instead the present invention could be applied to another type of ink jet head such as a thermal jet head which uses force from expanding vapor bubbles to eject droplets, as disclosed, for example, in U.S. Pat. No. 5,159,349, the disclosure of which is hereby incorporated by reference. As shown in FIG. 9, a heat generating resistor 326 can be provided on an external wall of the partition wall 22' defining one of the ink channels 25. The heat generating resistor 326 can be formed as a film on the partition wall with electrodes 327, 328 provided on respective ends of the resistor 326 for applying a voltage to the resistor film in order to heat the resistor film. Further, although the manifold members 29, 30 were described as separate members in the above-described embodiments, an integral manifold member could be used instead.
In an ink jet head and an ink jet printer according to the present invention, two substrates are provided with energy-generating elements, which produce energy for ejecting ink. The two substrates are attached to either side of a plate member, thereby forming two sets of independent channel groups for ejecting different colored inks. Further, the plate member extends beyond the rear ends of the substrates. A manifold member which is formed with ink channels is attached to the corner portion formed between the side surface of the elongated portion of the plate member and the rear end surfaces of the substrates. This simple configuration allows provision of a compact head capable of full color printing at high density.
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An ink jet head including: a plate member having left and right sides opposite each other, a front end and a rear end opposite each other, and a length from its front end to its rear end; two substrates each having a front end and a rear end opposite each other and a length from its front end to its rear end shorter than the length of the plate member, each substrate being attached to one of the left and right sides of the plate member so that the substrates sandwich the plate member therebetween and the rear end of the plate member protrudes beyond the rear ends of the substrates, each substrate being formed with a channel group including a plurality of ink-ejection channels extending from its front end to its rear end; and a manifold portion attached to the rear ends of the substrates and to left and right sides of the protruding rear end of the plate member and formed with two ink-supply channels each in fluid connection with the ink-ejection channels of a corresponding one of the channel groups.
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BACKGROUND OF THE INVENTION
This invention relates to illuminated signs, and more particularly to an illuminated construction for display of a house number or the like.
SUMMARY OF THE INVENTION
In general the present invention comprises an illuminated house number construction that comprises a body portion of novel simplified construction wherein multiple function components thereof consist of simple extruded and molded parts that are readily assembled in sealed relationship.
More particularly, the main body portion is extruded, so as to include integral mounting shoulders for a light pervious front face, as well as mask sections that provide the indicia displayed on the front face.
As another aspect of the present invention the body portion further includes integral mounting shoulders for right and left end closure caps, such that the device can quickly be assembled with the internal components sealed from the environment.
As still another aspect of the present invention, the novel body portion further includes a raceway integrally formed during the extruding process that provides means for mounting the bulb socket and wiring in sealed relationship and at the proper location for effective illumination.
As still another aspect of the present invention, the construction is provided with uniquly mounted riser legs that adapt the device for its location on window sills.
It is therefor a primary object of the present invention to provide a novel illuminated construction for displaying house numbers or the like which construction is uniquely formed from simple multiple function extrusions and mouldings whereby a high degree of economy is achieved with respect to both fabrication of components and assembly thereof.
Further object and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the invention is clearly shown.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation view of an illuminated construction fabricated in accordance with the present invention;
FIG. 2 is an end elevational view corresponding to FIG. 1;
FIG. 3 is a front elevational view of the construction of the preceeding Figures with the front face removed and;
FIG. 4 is an end elevational view, showing the construction of the preceeding Figs. with the end closure caps removed.
FIG. 5 is a bottom elevational view of an extruded numeral blank comprising a position for the construction of the preceeding Figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring in detail to the drawings, an illuminated display device constructed in accordance with the present invention is shown in FIGS. 1 and 2 and comprises a main body means indicated generally at 20. Such body means is of constant cross-sectional shape along its longitudinal axis and is therefor adapted to be fabricated by a continuous extrusion process with simple cut-off operations at intervals along the extruded work piece.
As seen in FIGS. 3 and 4, body means 20 includes integrally extruded top, rear and bottom wall portions indicated at 22, 24 and 26 respectively, as well as an upper shoulder 28 forming an upper face mounting slot 30 and a lower shoulder 29 forming a lower face mounting slot 32.
As seen in FIGS. 3 and 4, the corners of the body means includes small continuous ribs 71 that form longitudinal slots 72 for receiving self-tapping screws 74 with such screws being used to mount a right end closure cap 44 and to mount a left end closure cap, as seen in FIGS. 1 and 2.
Each of the caps 44 and 46 are formed as identical castings symetrical with respect to a vertical plane and include peripherally extending cap mounting shoulders 41 and 43 that register with left and right wall edges 35 and 37 on the main body means 20, as well as with right and left face edges 40 and 42 provided on the ends of a light transmitting front face member indicated generally at 34.
As is best seen in FIGS. 3 and 4 front face member 34 is of constant cross-sectional shape, so as to be continuously extrudeable from colored translucent symthetic resinous material, and cut off to lengths corresponding to the length dimension of the main body portion 20.
A suitable and economical material for moulding and extruding the above mentioned parts is medium impact styrene plastic.
Referring again to front face member 34, this part includes an upper face edge 36 adapted to slide into the previously mentioned face mounting slot 30 formed in main body means 20, as well as a lower face edge 38 that slides into the lower face mounting slot 32 in the lower front edge of the body means. Hence the front number 34 can quickly be removeably mounted in place on the body means.
With continued reference to FIGS. 3 and 4, front face member 34 further includes upper and lower extruded shoulders forming upper and lower face member slots 90 and 92 for receiving and mounting indicia blank means in the form of a plurality of numeral indici or blanks one of which is shown at 88 in FIG. 5. Numeral blank 88 is of a constant cross sectional shape, so as to be continuously extruded from clear transparent synthetic resinous material. Next is convenient extruded lengths, multiple controlled opaque background is applied by silk screen process to form an opaque mask 86, leaving a transparent area of numeral blank 88 in the shape of the desired numeral. It will be noted from FIG. 5 that the vertical edges of numeral blanks include offset protrusions 89 and 91 that are adapted to overlap one another when assembled as seen in FIG. 1 such that the edge junctions are sealed against the leakage of light.
Masked numerals 86 are then cut off to lengths corresponding to height formed by slots 90 and 92 and selectively assembled in overlapping edge to edge relationship in above described face mounting slots 90 and 92 in overlying relationship with colored face member 34 thus exposing thrue transparent area 88 the colored translucent face of member 34 in the shape of the desired number.
As an alternate front face construction, a one piece opaque contact vinyl mask is applied to entire surface of face member 34 selective numerals are then cut in mask and removed, leaving an opaque background. While removed area of mask exposes a colored translucent area of face member 34 in the desired shape of numerals.
Referring again to FIGS. 3 and 4, a wiring raceway 52 is provided by intergrally extruded ribs 50 and 56, and a raceway cover 54 mounted on said ribs by self-tapping screws 64 which are screwed into extruded slot 62. Cover 54 is provided with a down-turned rear edge that engages the top edge of rib edge 56 and a conventional socket 60 is mounted on raceway cover 54, such that the light bulb 66 can be positioned and retained at the proper location for efficient illumination of the front face member.
As shown in FIG. 1, the device is provided with riser legs indicated generally at 80 which are fabricated by extruding and cut-off operations, so as to include open ended slots 84 that slideably mount on protrusions 82, the latter being integrally moulded on the bottom edges of end closure caps 44 and 46. Such riser legs adapt the device to be positioned on a window sill at a high enough location, so as to be visible through the pane of a window above the lower frame thereof.
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An illuminated sign construction for displaying house numbers or the like that is constructed from simplified multiple function extruded and moulded components that are assembled in sealed relationship, and which are adapted for the mounting of selected indicia on an illuminated face.
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BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for the digging of ditches through rocky soils. In particular, the present invention relates to an apparatus for excavating hard soils and rock which operates by concentrating the force exerted by the apparatus against the hard soil at one or more specific points at any given moment so as to increase the ability of the apparatus to excavate the hard soil.
Ditching and excavating machines fall into two basic categories, the "power shovel" type and the "continuous ditcher" type. There are two basic types of continuous ditching and excavating machines, the "rigid wheel" and "chain" types.
The first continuous ditchers were rigid wheel machines, and were developed in very large sizes for use in such applications as the digging of irrigation canals. The more recently developed chain type of ditcher is smaller, more portable, more maneuverable and a more versatile unit. However, both wheel and chain types of ditchers penetrate hard soils poorly and are generally ineffective in massive rock formations. Excavation of massive, hard rock, requires the use of shovels or blasting in conjunction with shovels. Excavation of these harder soils with shovels or blasting has a number of disadvantages, the most serious being that shovel systems require a relatively large area in which to operate and that blasting may harm adjacent structures and is characterized by a great deal of noise and shock waves. There is, therefore, a need for continuous ditchers which are capable of excavating hard formations.
A commonly used type of chain ditcher is characterized by an elongated boom mounted on a supporting structure such as a tractor. The boom is pivoted to the tractor and is provided at both ends with a pair of sprockets, around which a heavy chain passes. The links of the heavy chain are provided with sockets welded to them in an orderly pattern such that when cutting teeth are placed in the sockets, the cutting surfaces of the teeth will cover the entire width of the ditch to be dug at least once in a complete revolution of the chain around the boom. Rotation of the chain as the boom is lowered causes the cutting teeth to abrade and chip away the material in front of the chain until the boom reaches the desired depth and cutting angle. The entire unit is then moved slowly forward so that the ditch is elongated at full depth in the direction taken by the tractor.
As the unit is moved forward, the cutting elements of the chain engage the entire face of ditch; that is, its entire "slant height" times the full width of the ditch. Only the tooth points actually touch the face of the ditch, but all the points on the chain along the entire face of the ditch are being advanced at the rate of the advance of the tractor, therefore, all the points are sharing approximately equal parts of the total effort available to rotate the chain and to advance the chain against the face of the ditch.
When each tooth's share of rotational chain pull and contact pressure is enough to give some pentration into the soil, rock will be chipped and routed from the face of the ditch and the ditching is accomplished at a meaningful rate. Chips and other spoil materials are lifted out of the ditch by the drag and impact forces imparted in an upward direction along the face of the ditch by the rapid rotation of the chain. However, if the rock is of sufficient hardness to resist the penetration of the teeth, the teeth slide along the surface of the rock instead of penetrating into it. The sliding of the teeth along the surface of the rock results in the abrasion of the rock rather than the ripping and cutting necessary for efficient elongation of the ditch. This abrasion generates a large amount of noise and dust and also increases the rate of wear on the cutting teeth.
Some improvement in efficiency has been provided by the redesign of the cutting elements. For instance, a current design utilizes a single point of tungsten carbide mounted on the link of the chain to give a good "claw" angle and to rotate in its socket so as to stay relatively sharp. Although this type of cutting element is less suceptible to the wearing caused by the sliding of the cutting element along the rock surface, the ditching process is still relatively slow, and the cutting elements do eventually wear out.
Another approach has been to use heavyweight units and traction systems capable of slipping the crawler tracks of the tractor upon which the ditching apparatus is mounted. Machines are currently available in the 90 ton class, but they are out of the price range of almost all general contractors, and in spite of their tremendous size and cost, do not represent a significant improvement.
A reduction in the number of cutting elements mounted on the chain links will increase the contact pressure of each of the remaining cutting elements. However, such a reduction concentrates all the wear on the remaining cutting elements, thereby reducing the average "redundancy" so that the loss of one or two cutting elements may require that the unit be shut down so that these cutting elements can be replaced. Further, there is a limit to the number of cutting elements which can be removed before the remaining cutting elements are incapable of excavating the entire surface of the ditch. For instance, approximately 30 cutting elements are required to adequately cover a ditch which is approximately 24 inches wide. In addition, even though each individual cutting element is more productive, the reduced number of cutting elements being employed and the greatly reduced spoil removal effects are disadvantages which effectively cancel the benefits of a reduction in the number of cutting elements.
It is, therefore, an object of the present invention to provide a ditch digging apparatus capable of excavating hard soils which is of similar size, weight, and traction to current ditching machinery. Another object of the present invention is to provide a ditch digging apparatus capable of excavating hard soils with a chain size, form and number of cutting structures which is equivalent to current ditching machinery. Another object of the present invention is to provide a ditch digging apparatus capable of excavating hard soils which is characterized by chain-drive horsepower, speed, and position controls which are similar to existing machinery.
It is another object of the present invention to provide a ditch digging apparatus in which a relatively large proportion of the tractive effort and rotating chain pull of the apparatus is applied to as few as two to four cutting elements at a given instant. It is also an object of the present invention to provide a ditch digging apparatus capable of excavating hard soils with cutting elements which are not worn away as quickly as those of currently available units.
Still another object of the present invention is to provide a boom for a ditch digging apparatus which is capable of excavating hard soils. Another object of the present invention is to provide a boom for a ditch digging apparatus in which the cutting force of the cutting elements of the apparatus is concentrated at one or more specific points along the apparatus at a given moment.
SUMMARY OF THE INVENTION
The objects of the present invention are achieved by providing an apparatus for excavating hard soils comprising an elongate boom pivotally mounted to a traction unit, an endless chain capable of movement relative to the elongate boom and the traction unit, drive means for moving the endless chain, means mounted on the endless chain operable to penetrate the hard soils, and means for concentrating the force exerted by said soil penetrating means at a specific point at a given moment along the endless chain while said endless chain is being moved relative to the boom and the traction unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevated, perspective view of an apparatus constructed in accordance with the present invention.
FIG. 2 is a longitudinal cross-section through the elongate boom of the apparatus shown in FIG. 1.
FIG. 3 is a cross-section taken along the lines 3--3 in FIG. 2.
FIG. 4 is a cross-section taken along the lines 4--4 in FIG. 2.
FIG. 5 is a cross-section taken along the lines 5--5 in FIG. 2.
FIG. 6 is a cross-section taken along the lines 6--6 in FIG. 2.
FIG. 7 is an elevated, perspective view of the hydraulic cylinder and wear plate assembly disassembled from the boom shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a traction unit, designated generally at 10. A power source is contained within the traction unit 10. The traction unit 10 is provided with tracks 12 for forward motion of the traction unit 10 under the power provided by the power source. A console 14 is provided with controls 16 so that the operator of the unit can operate the unit from chair 18.
The traction unit 10 is provided with an elongate boom assembly 20 pivotally mounted to the traction unit 10 on shaft 22. Shaft 22 (see FIG. 2) is journaled into the traction unit 10 about flanges 24 and 26 on the traction unit 10 and the hood 28. The boom assembly 20 may be raised or lowered under the influence of hydraulic cylinders (not shown), one end of which is secured to the traction unit 10, the connecting rod 32 of which is pivotally mounted to arm 34 on axle 36. Arm 34 is pivotally mounted to the cross-bar 38, which passes through the hood 28 such that the hood 28 is raised and lowered simultaneously with the changes of elevation in the boom assembly 20. Cross-bar 38 is journaled within the reinforcement box 40, which is integral with the rest of the boom assembly 20, so that extension or retraction of the hydraulic cylinder (not shown) will cause corresponding elevation or lowering of the boom assembly 20.
The traction unit 10 is also provided with hydraulic motor 46 to rotate the endless belt 42 of conveyor 44 to remove the spoil which is pulled up out of the trench being dug. Another hydraulic motor 41 is provided to rotate the endless chain of links 50 around the boom 20.
Referring now to FIG. 2, the shaft 22 is journaled in the reinforcement box 40 while also acting as an axle for sprocket 48. Sprocket 48 is driven by the hydraulic motor 41 within the traction unit 10. Stringers 52 and 54 are integral with the reinforcement box 40 and provide the top and bottom of the frame of the boom assembly 20. An elongate wear plate 56 is welded to and extends beyond the top stringer 52. At the end of the boom assembly adjoining the reinforcement box 40, the top stringer 52 and bottom stringer 54 are provided with areas 53 and 55, respectively, which are wider than the width of the stringers 52 and 54. Bolts 58 are threaded through holes 60 in the portion 53 and 55 of the stringers which projects beyond the width of the wear plate 56, through the holes 62 in the reinforcement box 40 and are held in place by the nuts 64 (see FIG. 3). Integral with the top and bottom stringers 52 and 54, and forming the remainder of the frame of the boom assembly 20, are the side plates 66a and 66b.
Welded to the side plates 66a and 66b at the other end of the boom assembly 20 from the reenforcement box 40 is cross bar 68, best shown in FIG. 5. Cross bar 68 is provided with pin 70 which projects through holes in the ears 74a and 74b. Integral with the ears 74a and 74b is hydraulic cylinder 76, the connecting rod of which is forked to form two ears 78a and 78b, best shown on FIG. 2. Connecting rod ears 78a and 78b are provided with holes through which pin 80 projects. Pin 80 is integral with the cross bar 82, and the ends of cross bar 82 are welded to the side walls 84a and 84b (FIGS. 5 and 6) of the extendible box formed by the side walls 84a and 84b and integral top and bottom walls 86a and 86b. The extendible box formed by the integral side walls 84 and top and bottom walls 86 is movable longitudinally within the boom assembly under the influence of the hydraulic cylinder 76. The extendible box formed by the integral side walls 84 and top and bottom walls 86 is held in place in the frame of the boom assembly by the combined action of the cross bar 68, which is integral with the side plate 66a and 66b, such that it is contained within the slot 87a and 87b in the side walls 84a and 84b of the extendible box and the runners 88a and 88b, and plate 90, both of which are also integral with the side plates 66a and 66b of the frame of the boom assembly 20. Additional rigidity is provided by the bolts 92a, 92b, 92c and 92d which project through holes in the runners 88a and 88b and the side plates 66a and 66b. The bolts 92a, 92b, 92c and 92d are held in place by the corresponding nuts 94a, 94b (not shown), 94c and 94d (not shown). Journaled in the forward extension 96a (not shown) and 96b of the side walls 84a and 84b of the extendible box formed by the integral side walls 84 and top and bottom walls 86 is shaft 98 which serves as an axle for idler 100. The side walls 84a and 84b, with their forward extensions 96a and 96b carrying the shaft 98, with the integral idler 100, can be extended or retracted under the influence of the hydraulic cylinder 76.
Integral with top stringer 52 are ears 102a, 102b, and 102c. Ears 102b and 102c are mounted to base plates 104b and 104c which are welded to top stringer 52. Ears 102a, 102b and 102c are provided with integral pins 106a, 106b and 106c, respectively, which project through the holes 108a, 108b and 108c, respectively, of hydraulic cylinder mounts 110a, 110b and 110c. Hydraulic cylinder mounts 110a, 110b and 110c are integral with hydraulic cylinders 112a, 112b and 112c, respectively (see FIG. 7). Piston rods 114a, 114b and 114c project downwards from each respective hydraulic cylinder 112a, 112b and 112c and are pivotally mounted to plate members 116a, 116b, 116c and 116d at the points at which adjacent plate members are hinged such that the piston rod 114a is pivotally mounted to plate members 116a and 116b, piston rod 114b is pivotally mounted to plate members 116b and 116c, and piston rod 114c is pivotally mounted to plate members 116c and 116d. Hydraulic cylinders 112a and 112c, with their corresponding piston rods 114a and 114c, extend through holes in the bottom stringer 54 in the case of the hydraulic cylinder 112a and piston rod 114a and in the bottom well 86b and plate 90 in the case of hydraulic cylinder 112c and piston rod 114c. The piston rods 114a, 114b and 114c and the overlapping outside tabs 118a, 118b and 118c and inside tabs 120a, 120b and 120c on the plate members 116a, 116b, 116c and 116d are pivotally joined by pins 122a, 122b, and 122c. Pairs of spacers 124a, 124b, and 124c are provided between the overlapping outside tabs 118a, 118b and 118c and inside tabs 120a, 120b, and 120c, respectively. Each of the plate members 116a, 116b, 116c and 116d is provided with longitudinal stringers 126a, 126b, 126c and 126d and cross stringers 128a, 128b, 128c and 128d for added rigidity. Welded to the bottom of the plate members 116a, 116b, 116c and 116d are wear plates 130a, 130b, 130c, and 130d, respectively.
The hydraulic cylinders 112a, 112b, and 112c are extended and retracted under the influence of hydraulic fluid pumped by a pump (not shown) powered by the engine (not shown) of the traction unit 10 through the fluid input lines 132a, 132b and 132c and the fluid output lines 134a, 134b and 134c.
Plate member 116a is provided with an integral cross bar 142 (FIG. 7) which is welded to the longitudinal stringers 126a of plate member 116a. The cross bar 142 is secured to the frame of the boom assembly 20 between L-brackets 154a and 154b integral with the bottom stringer 54. The distance between the upper surface 156a and 156b of the L-brackets 143a and 154b, respectively, and the lower surface 158 of the bottom stringer 54 is slightly greater than the thickness of the cross bar 142, thereby allowing some motion within the space between the upper surface 156 of the L-brackets 154 and the lower surface 158 of the bottom stringer 54 so that the individual plate members 116a, 116b, 116c and 116d of the plate assembly can pivot on the pins 122a, 122b and 122c.
At the other end of the plate member assembly shown in FIG. 7, plate member 116d is provided with a pivoting table 144 mounted on an axle 146 journaled in holes 148 in the longitudinal stringers 126d of plate member 116d. Spacers 150 are provided to cooperate with the vertical brackets 152, which are integral with the pivoting table 144, to prevent lateral movement of the plate member assembly along the axle 146. The pivoting table 144 is secured between the forward of the side plates 66a and 66b, and for further rigidity and strength, is also welded to plate 90.
Each link of the endless chain of links 50 is provided with a cross plate 136 upon which an integral socket 138 is mounted with an integral tooth 140. For clarity, only a portion of the endless chain of links 50 is shown with sockets 138 and teeth 140 in FIG. 2. The sockets 138, with the teeth 140 mounted on them, are arranged on the cross members 136 in an orderly pattern along the length of the endless chain of links 80 such that the cutting surfaces will cover the entire width of the proposed ditch at least once in a complete revolution of the endless chain 50 around the boom assembly 20.
Any slack which may be present in the endless chain of links 50 is taken up by loosening bolts 92a, 92b, 92c and 92d and then pumping grease into hydraulic cylinder 76 through grease fittings 101 with a separate grease pump, not shown. The additional grease causes the extension of the connecting rod ears 78a and 78b, and the corresponding extension of the extendible box formed by the integral side walls 84a and 84b and top and bottom walls 86a and 86b, carrying the forward extension 96a and 96b, shaft 98 and idler 100 with it. Bolts 92a, 92b, 92c and 92d are then re-tightened, locking the extendible box in place. As the endless chain of links 50 relaxes due to continued use, this extension process is repeated. However, it is an infrequent adjustment.
In operation, the traction unit 10 is driven to the appropriate location for the start of the ditch, and the hydraulic motor 41 is then engaged to begin rotation of the sprocket 48 on shaft 22 to turn the endless chain of links 50. The boom assembly is then lowered by engaging the hydraulic cylinders (not shown) such that the tip of the boom assembly 20 engages the soil surface and begins to rout out the soil. As the tip of the boom assembly 20 penetrates further into the ground and rocky soils are engaged, the hydraulic cylinders 112a, 112b and 112c are energized and reciprocate automatically in cycles such that they move up and down at equal speeds but at different times. If a complete extension-retraction cycle of any one of the cylinders is considered a 360° rotation, the extension of the cylinders is timed 120° apart such that only one of the three hydraulic cylinders is fully extended at any given time. Thus, the wear plates 130a, 130b, 130c and 130d are being pushed downward to present an ever-shifting pattern of advance of the boom assembly 20 through the rocky soil and a different cutting angle at any given moment. Because the advance of the wear plates is several times the rate of advance of the traction unit 10 along the ground to be ditched, only a very small area of the endless chain of links 50 will be fully engaged with the rocky soil at any given time. In this manner, the cutting force of the teeth 140 mounted on the cross members 136 of the endless chain of links 50 is concentrated at specific points at specific times, and unloaded at other times, thereby maximizing the cutting force of the teeth 140. Damage to the sprocket 22, idler 100, hydraulic cylinders 112a, 112b and 112c, hydraulic cylinder 76 and the other moving parts inside the boom assembly 20 by stones and spoil is controlled by shielding the moving parts with the side plates 66a and 66b to exclude gross amounts of these contaminants.
The embodiment discussed is but one means of achieving the desired concentration of the cutting force of the teeth at a given point along the length of the boom assembly. This concentration of force may be accomplished by other embodiments of the invention, the above-described embodiment being only the preferred embodiment. Other such means will occur to those skilled in the art who have the benefit of this disclosure, and all such changes, embodiments and modifications are considered to be a part of the present invention, the scope of which is limited only by the following claims.
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Apparatus for excavating hard soils comprising support means, an endless chain capable of movement relative to said support means, drive means for moving said endless chain, means integral with said endless chain operable to contact said hard soils, and means for concentrating the force exerted by said soil contacting means against said hard soils at a specific point along said endless chain while said endless chain is being moved relative to said support means.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to a sealing system between a relatively rotating element and a stationary element, possibly a drill pipe and a wash pipe.
[0003] 2. Related Art
[0004] Drilling is done by having a rotating drill pipe extending between the drill bit and the surface facility. The surface facility is either on land, on a floating vessel, a platform or other kind of installation. There will naturally be relative rotation between the drill pipe and the surface facility. At the same time there are fluid lines in the drill pipe which need to be connected to equipment on the surface facility for transfer of a fluid from a fluid path in the drill pipe to the surface facility. One possible solution for this is to provide swivel means in the connection between the drill pipe and the surface facility. Such swivel means may for instance be a so-called washpipe connected to the drill pipe. These swivel means should also prevent leakage of fluids to the environment and preferably be easy to use, assemble and repair. The swivel means also has to withstand high pressure and high speed drilling with the associated extensive abrasion and wear in the connection between the relatively rotating elements.
[0005] There is known a washpipe assembly for a standard drill pipe where the system includes hydrodynamic seal lubrications where each seal has a dynamic sealing surface incorporating a wavy hydrodynamic inlet and a non-hydrodynamic exclusionary corner, pressure staging between the hydrodynamic seals where the drilling fluid pressure is divided among three pressure retaining seals, exposing each one to only a fraction of the pressure, where each sealed chamber is independently pressurized by a lubrication cylinder (lubricator energized by the drilling fluid pressure and pivoting articulation), as described in the paper IADC/SPE 59107 “A new hydrodynamic Washpipe Sealing system. Extends Performance Envelope and Provides Economic Benefit” by Morrow, Drury, Dietle and Kalsi. Such an assembly will enable it to withstand significantly higher pressures and surface speeds compared with conventional units.
SUMMARY
[0006] According to one or more embodiments of the present invention, there is provided a sealing system between a relatively rotating element and a stationary element, comprising at least three sealing elements arranged between the two elements and arranged in series between a process fluid and an environment. There is a barrier fluid arrangement to provide a barrier fluid between the sealing elements, where the barrier fluid arrangement comprises at least two compensator devices where the pressure in the process fluid is acting on one side of a piston in the compensator device and the pressure in the barrier fluid is acting on the opposite side of the piston.
[0007] According to one or more embodiments of the invention there is a difference in the cross sectional area of the two sides of the piston and this difference varies between the at least two compensator devices. This gives that with a given compensator device there is a given pressure difference between the pressure in the process fluid and the pressure in the barrier fluid. This pressure difference is set with the difference in cross section areas of the two sides of the piston for each compensator during assembly of the sealing system and thereby forming a passive sealing system. The sealing system is provided with filling means for adding barrier fluid to the system. These filling means may provide a possibility for providing barrier fluid to each one of the compensator devices at a given pressure before active use of the sealing system. The filling means may provide a possibility of providing barrier fluid from one fluid source at a given pressure to at least two compensator devices at the same time, which filing means when the sealing device is in active use are closed, or the barrier fluid source is removed from the filling means. The filling means may when the filling means provide the possibility of providing barrier fluid to two or more compensators at the same time be closed by a one-way valve in the connection to each of the compensator devices, preventing fluid from flowing out of the sealing system when the barrier fluid has been added through the filing means and also preventing barrier fluid to flow between the different compensator devices. The filing means may thereby be a one point contact between the sealing system and the source of barrier fluid, with valves in the connection to each of the compensator devices. Alternatively there may be more than one filing means connected to groups of compensator devices or possibly one filing means for each compensator device. The issue is that the barrier fluid is filled to the sealing system with a given pressure and then during active use the system as such will then provide a pressure in the barrier fluid in response to the pressure in the process fluid and by the construction of the different compensator devices the process fluid pressure is divided between the different compensator device and one thereby achieves a passive system which responds to the differences in the process fluid pressure.
[0008] According to an aspect of the invention the rotating element may be a drill pipe and the stationary element may be a washpipe and there may be a radial opening from the drill pipe through the wash pipe. This radial opening may be in addition to an axial opening. Such a configuration with a radial opening and an axial opening may be found in a dual drill pipe. A dual drill pipe may comprise a normal drill pipe with an inner pipe arranged within the drill pipe forming an annular space between the drill pipe and the inner pipe, in addition to the space within the inner pipe. This annular space may be connected to surface equipment through a radial opening. The inner space of the inner pipe may in a conventional manner have an axial opening at the top of the drill pipe. The annular space with the radial opening may be used to provide drilling fluid down to the drill bit, and the drill fluid with cuttings may be transported back to the surface through the inner space of the inner pipe. It is also possible to envisage an opposite transportation of fluids.
[0009] According to an aspect the piston in the compensator device may be arranged with a piston rod on one side. The cross sectional area of the piston rod may then be used to adapt the difference in the cross sectional area of the two sides of the piston.
[0010] According to another aspect the compensator devices may comprise cylinders for positioning of the piston, which cylinders have a similar inner diameter for at least two of the compensator devices in the sealing system. This will give similar pistons in several compensators, possibly all the compensators in the sealing system. The cross sectional difference may then be achieved by attaching piston rods with different cross sectional areas to the different pistons.
[0011] According to another aspect at least one of the pistons may be an annular piston positioned around an inner piston. There may be several annular pistons arranged outside each other with a common centre axis. Another possibility is to have several sets of annular pistons or alternatively some annular pistons and some other pistons.
[0012] According to another aspect there may be one fluid supply of barrier fluid to the at least two compensator devices. The one fluid supply may be to all the compensators or there is one barrier fluid supply to some compensators and another fluid supply to some other compensators.
[0013] According to another aspect a first compensator device may be connected to a first space between a first sealing element, exposed to the process fluid, and a second sealing element, and it may be arranged to have the barrier fluid acting on the side of the piston with a smaller exposed area of the piston than the side of the piston acting on the process fluid. This will give a somewhat higher pressure in the barrier fluid than in the process fluid, limiting the exposure of the seal to the process fluid. During normal operations barrier fluid will leak towards the process fluid and not the other way. The compensator devices connected to other spaces between sealing elements may be arranged to have the barrier fluid acting on the side of the piston with a larger exposed area of the piston than the side of the piston exposed to the pressure within the process fluid. This gives a predefined pressure drop from the process fluid to the barrier fluid.
[0014] According to another aspect the piston rods may be extending out of the compensator as a visual indicator. This may also indicate which piston is connected to which seals in the sealing system, as these piston rods may have different cross section area.
[0015] According to another aspect the at least two compensator devices may be arranged at least partly within the outer relative stationary element. They may be arranged in a line or divided around the circumference of the outer element or as a combination. The barrier fluid supply may also be arranged at least partly within this element, or alternatively the at least one filling means are arranged easily accessible in the outer surface of the outer relative stationary element. Such a configuration will avoid external lines for supply of barrier fluid to the outer element.
[0016] According to another aspect one compensator device may be providing a barrier fluid to two spaces between two sealing elements, one space on either side of the opening. With a radial opening such a configuration is a good solution. Such a configuration will give the need for half the amount of compensators compared with a solution with one compensator for each space. With a radial opening there will also be symmetry around the opening. The sealing elements and the spaces will also extend all the way around the drill pipe, forming ring shaped sealing elements and spaces for the barrier fluid.
[0017] According to another aspect the cross sectional area on one side of the pistons in the compensator devices, exposed to the pressure in the barrier fluid may be mainly equal for almost all the compensator devices. This give similar pistons in all the compensators, and easy production. The cylinder for the movement of the pistons may be formed by a separate element or at least partly by the outer relative stationary element.
[0018] According to one or more embodiments of the present invention, a method for operating a sealing system between a relatively rotating element and a stationary element comprises arranging at least three sealing elements in series between the two elements and between a process fluid and an environment, arranging a barrier fluid arrangement to provide a barrier fluid in spaces between the sealing elements, providing at least two compensator devices in the barrier fluid arrangement and arranging them such that the pressure in the process fluid is acting on one side of a piston in the compensator device and the pressure in the barrier fluid is acting on the opposite side of the piston, providing a difference in the cross sectional areas of the two sides of the piston and adapting the difference in the cross sectional areas of the pistons of the different compensator devices such that the pressure difference between the process fluid and the environment is divided between the different compensator devices.
[0019] According to another aspect the method may comprise providing a barrier fluid with a given pressure in the system before active use of the sealing system, and then removing the barrier fluid source from the sealing system until the sealing system again should be filled or filled up with barrier fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is an elevated sketch a washpipe in connection with a drill pipe,
[0021] FIG. 2 is a cross section of the system in FIG. 1 , and
[0022] FIG. 3 is a schematic sketch of the barrier fluid system in the sealing system.
DETAILED DESCRIPTION
[0023] Hereafter, embodiments of the invention will be described. In embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid obscuring the invention.
[0024] In FIG. 1 there is shown an elevated sketch of a drill pipe 1 , forming the rotating element, with a washpipe 3 , forming the stationary element attached to the drill pipe 1 . There is in the drill pipe 1 indicated another inner pipe 6 . Between the drill pipe 1 and the inner pipe 6 three is formed an annular space 7 and there is an inner space 8 within the inner pipe 6 . Normally the annular space 7 will be used for transporting fluid, a process fluid into the well which is added to the annular space through a opening 5 in the washpipe 3 , as indicated with the arrows and a return fluid is moved out of the well through the inner space 8 of the inner pipe 6 as also indicated with the arrows. There may to the opening 5 be attached a pipe from the stationary surface equipment, comprising for instance a valve means for regulating the flow into the annular space 7 through the opening 5 .
[0025] As shown in FIG. 2 which is a cross section of the element in FIG. 1 the drill pipe 1 is formed with holes 2 through the wall of the drill pipe 1 . These holes 2 leads to an inner annular cavity 4 formed in the inner surface of the washpipe 3 . This inner annular cavity 4 is in connection with the opening 5 . Between the opposing surfaces of the washpipe 3 and the drill pipe 1 there are arranged several sealing elements 10 , in series, on both sides of the annular cavity 4 . The sealing elements 10 are annular sealing elements and are arranged within grooves in the washpipe 3 . It is possible to envisage that the sealing elements are arranged in grooves in the drill pipe. As these sealing elements 10 are arranged around the circumference of the drill pipe 1 and in abutment against the drill pipe 1 and the washpipe 3 there are formed annular spaces 11 between two neighboring sealing elements 10 . There are nine sealing elements 10 arranged in series on both sides of the annular cavity 4 in the shown example. The series of sealing elements 10 may comprise three or more sealing elements 10 forming at least two annular spaces 11 . There may be for instance five, six, seven or eight sealing elements forming four, five, six or seven annular spaces. According to one or more embodiments of the present invention, there are similar series of sealing elements 10 on both sides of the annular cavity 4 .
[0026] The wash pipe 3 is formed between two pipe flanges 22 attached to the drill pipe 1 with bearing arrangements 9 between the washpipe 3 and the pipe flanges 22 allowing and supporting relative rotational movement between the drill pipe 1 and the washpipe 3 . Another configuration is possible for allowing such relative movement. There is partly within the washpipe 3 arranged several compensator devices 21 . The compensator devices 21 comprises a cylinder 20 , wherein there is arranged a movable piston 16 . The cylinders 20 and pistons 16 are similar for all the compensator devices 21 . There is a sealing connection between the pistons and cylinders. To the piston 16 there is attached a piston rod 17 . The cross sectional area of the piston rod 17 is varied from one compensator device 21 to the next compensator device 21 ′. As one can see from FIG. 1 the piston rods 17 extend out of the compensator device and work as a visual aid. The compensator devices 21 are also positioned partly within the washpipe 3 and arranged around the washpipe 3 . There are as indicated with the process fluid line 14 in the washpipe 3 from the annular cavity 4 to the different compensators 21 provided internally bores to avoid external fluid lines for process fluid and barrier fluid to the different compensator devices 21 . Such a construction will give a compact device with minimal external fluid lines.
[0027] The connection between the different compensators 21 , the different process fluid lines 14 and barrier fluid lines 15 and the different spaces 11 between the sealing elements 10 are schematically given in FIG. 3 . The stationary element 3 with the grooves and the different sealing elements 10 are shown. Also in in one or more embodiments of the present invention, there are nine sealing elements 10 in series on both sides of the annular cavity 4 leading to the opening 5 for the process fluid. To the cavity 4 and or the opening there are connected a process fluid line 14 , guiding the pressure in the process fluid to the different compensators 21 . There are eight compensators 21 all with similar cylinders 20 wherein there are arranged pistons 16 . To the pistons 16 there are attached piston rods 17 . The process fluid lines 14 leads to a given side of the piston 16 . The pistons 16 have a first cross sectional area 18 and a second cross sectional area 19 . The process fluid lines 14 leads to the side of the piston 16 with the second cross sectional area 19 . There are in the system also a barrier fluid source 13 , connectable to the barrier fluid lines 15 leading to the spaces 11 between the different sealing elements 10 and to the compensators 21 . The barrier fluid lines 15 lead to the side of the piston 16 with the first cross sectional area 18 . The area differences between the first cross sectional area 18 and the second cross sectional area 19 , given by the cross sectional area 18 divided by the cross sectional area 19 , are different for all the compensators 21 .
[0028] There is one high pressure compensator 21 . 0 where the barrier fluid line 15 is connected to the first cross sectional area 18 where there to this side is connected a piston rod 17 and the second cross sectional area 19 is the full area of the cylinder 20 . This high pressure compensator 21 . 0 is connected to the space 11 between the sealing element 10 closest to the process fluid and the neighboring sealing element 10 . The high pressure compensator 21 . 0 provides a pressure in the barrier fluid delivered to the space 11 which is somewhat larger than the pressure in the process fluid in the annular cavity 4 . This higher pressure in the barrier fluid will give a leakage of the barrier fluid towards the process fluid, thereby preventing unnecessary abrasion of the sealing element 10 closest to the process fluid. The first compensator 21 . 1 is formed with the piston rod 17 connected to the second cross sectional area 19 of the piston 16 . The process fluid lines 14 are connected to this second cross sectional area 19 and the barrier fluid lines 15 are connected to the first cross sectional area 18 . The first compensator 21 . 1 delivers a barrier fluid with a pressure somewhat lower than the process fluid and is connected to the space 11 neighboring the space 11 connected to the high pressure compensator 21 . 0 .
[0029] The second compensator 21 . 2 , the third compensator 21 . 3 etc all deliver a barrier fluid pressure to different spaces 11 , reducing the pressure in the spaces 11 gradually the further from the annular cavity 4 the space 11 is positioned. Outside the space 11 connected to the seventh compensator 21 . 7 it is the pressure of the environment. All the compensators 21 are connected to two spaces 11 , one on each side of the annular cavity 4 , mirroring the sealing system on both sides of the annular cavity 4 . There is indicated a barrier fluid supply 13 . This may be used to fill the barrier fluid lines 14 to a given pressure before the sealing system is attached to the process fluid pressure. By such a system one is dividing the process fluid pressure between all the compensators, where the division of pressures on the different spaces 11 in sealing system is given by the difference in cross sectional area across the pistons 16 .
[0030] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
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A sealing system between a relatively rotating element and a stationary element has at least three sealing elements arranged between the rotating element and the stationary element and arranged in series between a process fluid and an environment, and a barrier fluid arrangement to provide a barrier fluid to spaces formed between the sealing elements. The barrier fluid arrangement has at least two compensator devices where under use the pressure in the process fluid is acting on one side of a piston in the compensator device and the pressure in the barrier fluid is acting on the opposite side of the piston. There is a difference between cross sectional areas of the two sides of the piston and the difference varies between the at least two compensator devices.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of my application Ser. No. 08/675,549, filed Jul. 3, 1996, and now U.S. Pat. No. 5,829,865.
TECHNICAL FIELD
The present invention relates to miniature decorative light sets with push-in type bulb holders in which lead wires from the bulbs are pressed into engagement with contact elements within the sockets receiving the bulb holders.
BACKGROUND OF THE INVENTION
It is common in decorative light strings to have light units comprising miniatures bulbs each seated in a socket provided by a holder which has a push-in fit with a housing having a socket containing two contact elements extending into a wireway in the base of the housing. The contact elements engage wires of the light string extending through the wireway. Each bulb has a pair of fine single-strand wire leads extending from the bulb through the base of the holder and doubled back about one-half inch against the outside of the holder so as to be pressed into engagement with the contact elements when the holder is pushed into the holder socket. Assembly of the bulb in the holder and the mounting of the bulb and holder in the housing are performed manually and require deft manipulation of the lead wires. Consequently, the doubled back portion of each bulb lead does not always end up in a position generally parallel to the longitudinal axis of the respective holder when the bulb is pushed into the housing socket. As a result there may be in some instances no initial contact between the lead and the respective contact element or later loss of contact after assembly during handling of the respective light set.
SUMMARY OF THE INVENTION
The present invention aims to provide an improved arrangement for positioning the bulb lead wires in engagement with the contact elements in the housing. This involves adding a pair of flexible longitudinal extensions to the bulb holders as legs which can easily be bent to assume a position between the bulb holder and contact elements when the bulb holder and bulb are inserted as a push-in unit in the light housing. Each extension has a slot at its free end arranged so that a respective bulb lead feeding from the holder can have a terminal end portion positioned in the slot and doubled-back to initially position an intermediate portion of the lead against the respective leg.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a layout of a light set using the light units of the present invention;
FIG. 2 is a perspective view of one of the light units mounted on a cord;
FIG. 3 is an exploded view of one of the light units in the center series of light units in FIG. 1;
FIG. 4A is an elevational view of a plug-in bulb holder assembly shown in exploded relation with a bulb in position for assembly therewith;
FIG. 4B is an elevational view showing the bulb in place with the bulb holder and the lead wires of the bulb engaging the flexible legs of the holder;
FIG. 4C is an elevational view like FIG. 4B, but showing the flexible legs of the bulb holder bent back in preparation for introduction of the bulb holder and bulb as a unit to the socket unit;
FIG. 5 is a detail side elevational view of the lower portion of the lamp holder as viewed at the left side of FIG. 4A;
FIG. 6 is a detail sectional view through the socket unit of the holder with a contact element in place;
FIG. 7 is a detail view showing in elevation the lower end portion of one of the contact elements installed and with the related cord shown in transverse cross section;
FIG. 8 is a longitudinal vertical sectional view taken as indicated by line 8--8 in FIG. 2; and
FIG. 9 is a bottom view of one of the light units mounted on a cord; and
DETAILED DESCRIPTION OF THE INVENTION
For purpose of example, lampholders embodying the present invention are illustrated as applied to a chaser set having two series of light units 10, 10' on two interrupted wires 12-13. These wires and a return wire 14 extend from a controller 16 in turn connected to a wall plug 17. At their outer ends the wires 12-14 are connected together within a suitable insulated shield 18. The controller 16 contains a switching mechanism for alternately completing a circuit to the wires 12-13.
The wires 12-14 are arranged in side-by-side spaced relation as part of a single cord 19 having insulation 19a surrounding and separating the wires. The cord 19 passes through a wireway 20 in each light unit 10-10', and the wires 12-13 are sectioned by respective cutouts 21 in the cord which are positioned in the wireways 20 of the light units 10-10'. Each cutout 21 extends through only the respective wire 12-13 and the related external insulation. The resulting gap between the wire segments on each side of the cutouts is bridged via a pair of contact elements and the leads from the filament of the bulb in the light unit in a manner to be described. The light units 10 and 10' are basically the same, the principal difference being that the contact elements for the light units 10' are modified to engage outer wire 13 rather than the center wire 12.
The light units 10 include an injection-molded two-piece plastic lampholder housing consisting of a socket unit 22 and a generally U-shaped base unit 23 which have a snap interfit and provide complementing gripping jaw portions 22'-23' forming the wireway 20 for passage of the cord 19. The wireway 20 is shaped by a set of three arcuate grooves 20a extending across the jaw portion of the socket unit 22 and a complementary set of three arcuate grooves 20b extending across the jaw portion 23' of the base unit 23. Within the wireway 20 the insulation 19a of the cord 19 is firmly gripped and compressed between the opposing jaw portions 22', 23'. the socket unit 22 has a pair of oppositely projecting flanges 22b providing end portions of the jaws 22' and grooves 20a. A socket cavity 22a extends along the length of the socket unit 22 for receiving a push-in bulb assembly 24 having an injection-molded plastic bulb holder 25 in which a bulb 26 with a pair of leads 27 from its filaments is mounted. Each light unit 10 is completed by a pair of elongated push-in contact elements 28 located at opposite sides of the socket cavity 22a and arranged to extend crosswise into the wireway 20. The contact elements 28 for the light units 10 are energized via the center wire 12 and fit into diametrically opposite guideways 29. The contact elements for the light units 10' which are energized via the wire 13 are wider and fit into a wider guideway provided in the socket cavity of a socket unit modified in that respect (not shown).
Projecting from the socket unit 22 on opposite sides of the wireway 20 are two locking legs 32 presenting opposed locking shoulders 32a adjacent their outer end for interfitting with the base unit 23. These shoulders 32a are adjoined by beveled lead-in faces 32b. The inner face of each locking leg 32 is transversely concave matching the curvature of the socket cavity 22a.
The base unit 23 has a pair of flexible guide fingers 34 shaped to engage the lead-in faces 32b and be flexed at their root end toward one another responsive to pushing of the base unit 23 and socket housing 22 together from opposite sides of the cord 19 after the base unit 23 has been positioned with the cord 19 straddled by the fingers 34 at the site of one of the cutouts 21. At their root end the fingers 34 have retaining shoulders 35 between a respective pair of curved base flanges 36, 36'. These shoulders 35 are engaged by the locking shoulders 32a when the base unit 23 and socket unit 22 are snap-fitted together over the cord 20. The guide fingers 34 are preferably arched transversely to provide each with a convex outer guide face 34a complementing the concave inner guide face of the respective locking leg 32, and the free end of each guide finger 34 is preferably rounded and beveled on its convex outer side as indicated at 34b. The base unit 23 presents a post 37 arranged between the fingers 34 to project into a selected cutout 21 in the cord 19. Two forms of base unit 23 are required, one for lights 10 with its post 37 arranged to extend through the cutout 21 in the center wire 12, as shown in FIG. 3, and the other for lights 10' to project through a cutout in wire 13.
The flanges 36, 36' on the base unit 23 each have curved wings 36a which define retaining recesses 39 that are generally V-shaped in plan view. As seen in FIG. 9, these recesses 39 receive side edge portions 32c of the locking legs 32 so that the curved base flanges 36, 36' keep the locking legs 32 from spreading apart after the base unit 23 and socket unit 22 are fitted together.
The bulb holder 25 has a central socket 40 to receive the bulb 26. This socket 40 is provided in a round head portion 41 having an outwardly flared annular rim 42. Below the rim 42 the bulb holder has a longitudinal section 43 presenting a pair of convex longitudinal faces 43a between a wider pair of flat longitudinal faces 43b, each of which is interrupted by a pair of laterally spaced longitudinal ribs 43c. Extending longitudinally from between each of these pairs of ribs 43c is a narrow flat land 44 which continues endwise beyond the adjacent end of the lamp holder as longitudinal flexible legs 45. These legs 45 initially are in generally parallel spaced relation as indicated in FIG. 4A. A longitudinal center passage 46 extends from the socket 40 through most of the remaining length of the bulb holder and exits through a pair of exit ports located adjacent the root ends of the legs 45. As shown in FIG. 5, the outer end of each leg 45 is preferably formed with a positioning slot 48 extending between flat inner and outer exterior faces 45a, 45b of the leg.
When the bulb 26 is being positioned in the bulb holder 25, the lead wires 27 are fed through the passage 46 and exit ports at the lower end of the passage to extend adjacent the inner faces 45a of the legs 45 to the positioning slots 48 by an intermediate lead section 27a. Then a short end portion 27b of the leads are bent to pass through the slot 48 and double back over the outer faces 45b of the legs as shown in FIG. 4B. It is preferred to have the ends of the slot 48 narrow to a width which will cause the lead wires 27 to be pinched where they pass through the slots to be doubled back over the outer faces 45b.
When the described arrangement of the lead wires 27 and flexible legs 45 has been accomplished, the legs 45, with the lead wires 27 in position thereon, can then be bent outwardly away from one another at their root ends and doubled back toward the body extension 44 as illustrated in FIG. 4C. This repositions the inner faces 45a of the legs 45 so that they face outwardly away from one another rather than facing inwardly toward one another as they were initially. This also repositions the intermediate sections 27a of the lead wires 27 so that they are exposed outwardly of the bent legs 45, and repositions the end portions 27b of the lead wires so that they are located between the initially outer faces 45b of the legs 45 and the adjacent outer face of the land 44. When the legs 45 are fully bent to the described double-back positions, the distance between the leg faces 45b is slightly less than the spacing between the contact elements 28 at opposite sides of the socket cavity 22a. This provides adequate space for the intermediate lead sections 27a which are pinched between the bent legs 45 and the contact elements 28 when the light units are assembled. It will be noted that the configuration of the bulb holder 25 and its flexible legs 45 is such that they can be injection molded as a one-piece part.
The bulb holder 25 is preferably provided with a locking finger 50 which projects from the annular rim 42 and has an inturned locking element 50a which is tapered at its bottom side. The locking finger is arranged to spring apart as it rides over a sloped entry ramp 51 on the socket housing 22 when the bulb holder 25 is pushed into the cavity 22a. Then the locking finger 50 springs inwardly at the outer end of the ramp 51 so that the locking element 50a engages a stop shoulder 52 beneath the ramp. The locking finger 50 has a pair of fork arms 50b which connect to the rim 42 of the bulb holder 25 and are separated by an opening 50c which overlies the locking element 50a. This arrangement makes it possible to injection mold the locking finger as an integral part of the bulb holder 25.
The ramp 51 is preferably located in alignment with one of the locking legs 32. Diametrically opposite the ramp 51 is a keyway 53 for receiving a positioning key 54 projecting radially from the bulb holder 25 at the base of the rim 42. The positioning key 54 and keyway 53 prevent the bulb unit 24 from being improperly positioned in the socket unit 22.
Referring to FIG. 7, the contact elements 28 are bifurcated at their lead-in ends to provide a pair of prongs 28a which are separated by a slot 28b and have V-shaped insulation shearing end portions 28c preferably sharpened along their outer edges 28d. As indicated in FIG. 7, the prongs 28a are designed to straddle and engage wire 12, for example, when the prongs pierce the insulation 19a of the cord 19 as the contact element 28 is pushed along a guideway 29 into the wireway 20 sufficiently for the tips of the prongs to bite into the plastic of the base wall of the base unit 23. Preferably, the outer longitudinal edges of the contact elements 28 are provided with one or more pairs of hold-in barbs shaped to bite into the adjoining inner portions of the socket unit 22.
Each contact element 28 is preferably provided with a blunt crimping element 58 at the closed end of the slot 28b. This crimping element 58 is positioned so that it engages the insulation 19a on the particular wire 12-14 straddled by the prongs 28a and presses (crimps) the insulation and wire together against the base unit 23 as indicated in FIG. 7. This pinches the insulation against the wire and assists in keeping the wire in proper position in electrical contact between the prongs 28a. The crimping element 58 is formed as an integral flange portion of the contact element during the stamping operation on thin metal brass stock. Preparatory to mounting the light units 10, 10' on the cord 19, the cord is passed through a suitable punching machine to make the cutouts 21 which are in alternating relation. Each light unit is then mounted by first positioning its base unit 23 beneath the cord with its post 37 projecting upwardly through the respective cutout 21. Then, after the socket unit 22 has been positioned above the cord in proper alignment with the base unit 23, the units 22-23 are pressed longitudinally together so that the locking shoulders 32a on the locking legs 32 of the socket unit are engaged by the retaining shoulders 35 at the root ends of the guide fingers 34 of the base unit 23. During this socket unit and base unit assembly operation the beveled lead-in face 32b on the locking legs 32, the rounded nose and adjoining bevel 34b on the guide fingers 34, and the complementing concave and convex shapes of the inner face of the locking legs 32 and outer face of the guide fingers 34 are of substantial assistance in properly aligning and guiding the parts. After a lampholder is mounted on the cord, the contact elements 28 are inserted by a suitable insertion machine through the open mouth of the socket unit 22 and along the guideways 29 so that the prongs 28a pierce the insulation 19a, straddle the wire and preferably bite into the base unit 23, and so that the crimping elements 58 press against the cord insulation 19a. It is important that while the prongs 28a pierce the cord insulation 19a, the sloped outer cutting edges 28d tend to be urged toward one another, thereby resisting spreading apart of the prongs 28a. With this arrangement of the contact elements 28 together with the cord clamping action of the interfitted socket and base units at each end of the wireway 20, the contact elements are maintained in engagement with the respective wire.
Assembly is completed by inserting the bulb assemblies 24 into the socket units 22 with the keys 54 seated in the keyways 53 and the locking fingers 50 engaging the stop shoulders 52. As previously discussed, when the bulb assemblies 24 have been prepared for insertion into the socket units 22 the legs 45 have been bent at their root ends such as to be doubled back toward the lands 44a. Normally when this is done there will be an acute angle between each leg 45 and the respective land 44a as shown in FIG. 4C. As the bulb assemblies are pushed into the socket units 22 the elbow portions 45c of the legs 45 are squeezed and the legs 45 are forced toward the lands 44 so that when the legs reach a position opposite the contact elements 28 the intermediate sections 27a of the leads are pressed firmly against the contact elements 28 and the end portions 27b of the leads are clamped between the legs 45 and the underlying flat lands 44 on the bulb holder 25.
From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
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A light set has multiple light units mounted on a multi-wire insulated cord, each light unit comprising a plastic push-in lampholders containing a bulb with two lead wires, a socket member receiving a pair of push-in contact elements and lampholder, and a base unit which snaps together with the socket member over the cord preparatory to insertion of the contact elements and lampholders. The contact elements pierce the cord insulation on opposite sides of a cutout through a selected one of the cord wires and establish positive contact with both parts of the severed wire by straddling respective of the wire parts with a pair of sharp prongs. Positive positioning of the bulb leads with respect to the contact elements is established by flexible leg extensions on the lampholders which interfit at their free ends with the leads and swing back to a position in the socket member pressing the leads against the contact elements.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a new multi-phase sunscreen agent with improved sunscreen properties.
2. The Prior Art
A multitude of sunscreen formulations are already known that contain certain organic and inorganic active ingredients as emulsions for filtering out (absorption or reflection) UVB radiation (range 290 to 320 nm) and UVA radiation (range 320 to 400 nm). Known organic active ingredients include in particular the derivatives of dibenzoylmethane, benzophenone, salicylic acid, cinnamic acid, 3-benzylidenecamphor, 4-aminobenzoic acid, etc. Known inorganic active ingredients include pigments such as the oxides of titanium, iron, zinc, silicon, aluminum, zirconium, etc. A mixture of organic and inorganic substances that is described as being superior to titanium dioxide is also known (European Patent EP A 588,498).
Published International Application No. WO 94/22419 describes a skin tanning agent where two components are present in separate containers and react when mixed together on the skin, producing a color.
The development of sunscreen formulations has mainly tended toward new active ingredients or a combination of known active ingredients. In general, these are present in emulsions to ensure a good and uniform distribution on the skin, where agglomerations of inorganic pigments have been prevented by surface-active substances.
However, hydrodispersions have also become known that do not contain any emulsifier and are a dispersion of a discontinuous lipid phase (liquid, solid or semisolid) in an external continuous (aqueous) phase. The stability of such an emulsifier-free system is achieved, for example, by creating a gel structure in the aqueous phase with a stable suspension of the lipid droplets in this gel structure. A disadvantage of these hydrodispersions is the required high concentration of UV filter materials and their stickiness.
European Patent EP A 603,080 describes a cosmetic or dermatological two-phase composition that consists of an aqueous phase and a separate oil phase containing alkyldimethylbenzyl-ammonium chloride in the aqueous phase and is suitable for skin care or for removing make-up.
World Patent WO 94/17779 discloses hydrodispersions which are emulsifier-free products to prevent possible irritating effects of emulsifiers (Mallorca acne). The stability of the dispersions is supposed to be ensured by an internal lipid phase with the inorganic pigments and an external aqueous phase.
SUMMARY OF THE INVENTION
The object of this invention is to achieve an improvement in the sunscreen properties through a particular arrangement of these agents in a formulation system and to prevent the chemical filters from coming directly in contact with the skin.
According to this invention, the new sunscreen consists of at least two separate and essentially liquid phases, where UVA and/or UVB filters and/or UVC filters (hereinafter: UV filters) are present in at least two separate phases, where the phases separate spontaneously after a brief and gentle mixing process, leaving the respective UV filters in the phase in which they were originally present.
It has been found that by spreading one of the separate phases on the skin and applying at least one second phase above it, where the second phase essentially does not mix with the first phase and each phase contains a UV filter, improved absorption of UV radiation is achieved in comparison with an emulsion or hydrodispersion containing the same amount of these UV filters. When converted to a sunscreen factor, this means an increase by at least two stages, preferably four to ten stages.
However, an improvement in the sunscreen factor is achieved even if only one phase contains a UV filter and the other phase does not contain any UV filter but contains different substances from the first phase, because the depth of penetration and the refraction of incident radiation differ according to the thickness of the layer and possibly the type of layer.
The sunscreen agent according to this invention consisting of at least two separate phases, preferably three of more phases, can be applied to the skin, where it develops these phases spontaneously again after application. This means that by rubbing the complete sunscreen agent removed from a storage container, the mixing process causes only an a momentary mixing effect which is then eliminated again almost completely due to the type of phases selected and their physical properties. The phase separation yields a layering effect of the sunscreen on the skin. The UV filters are selected so that after mixing, they are present again in the respective phase (layer) in which they were originally present, i.e., before the mixing process.
A preferred composition is, for example, the following, based on the skin surface:
(A) a phase that is directly against the skin and contains one or more fluorocarbons and an inorganic pigment as a UV filter;
(B) a phase above that, consisting of a polymer lacquer or a polymer film-forming compound in an organic solvent (hereinafter: polymer lac), optionally in mixture with a UV filter; and
(C) an oily phase above that, also containing a UV filter.
The proportion of phases, based on the total composition in such an example of a composition amounts to approximately: 15 to 35 wt % phase (A); 5 to 25 wt % phase (B); and 25 to 80 wt % phase (C).
Additional phases may also be included in the sunscreen agent, e.g., another oily phase (D) in the form of a silicone oil, optionally containing a lipophilic UV filter, as well as other phases.
With a layered structure having three or more phases, a phase consisting preferably of a polymer lac in a suitable solvent that is gentle to the skin is provided between an oily layer and a non-oily layer, for example. Shellac is an example of such a lac.
Shellac is a natural resin of animal origin with an average molecular weight of 1000 g/mol. It consists mainly of hydroxycarboxylic acids that are partially unsaturated, contain aldehyde groups and are in ester or lactone form. It has good compatibility with other resins, polymers and additives and is physiologically and toxicologically safe.
An example of a suitable polysiloxane copolymer that may be present in an oily phase would be poly (dimethylsiloxane) and poly(isobutyl methacrylate), a copolymer of poly(dimethylsiloxane) and polyacrylate, a copolymer of poly(dimethylsiloxane) and poly(isobutyl methacrylate)-containing copolymers (e.g., SA 70-5 from 3M Company, USA).
A suitable non-oily phase is preferably a phase containing fluorocarbons, especially perfluorocarbons. Perfluorocarbons that can be used include perfluorodecalin, perfluorotributylamine, perfluorooctyl bromide, bisfluoro (butyl)ethene or C 6 -C 9 -perfluoroalkanes and mixtures of these together and/or with perfluoropolyethers. A preferred perfluorocarbon is perfluorodecalin. A mixture of perfluorodecalin and perfluoropolymethylisopropyl ether is especially preferred. UV filters such as inorganic oxides or melanin are suspended in it. The viscosity of such a phase can be adjusted easily on the basis of the molecular weight of the perfluoropolyether.
The perfluorocarbons themselves are completely non-toxic and are very stable with respect to external influences such as physical and chemical influences (organic solvents, acids, alkali, UV radiation, temperature).
An advantageous mixing ratio of the mixture mentioned as especially preferred is in the range of 1.5-3:3-1.5.
A preferred phase composition may essentially be free of water.
The phase separation can be attributed to the different types of phase-forming basic ingredients or to definite differences in such physical properties as density and hydrophilic or hydrophobic properties. In general, a pronounced phase interface develops with each phase, preferably extending over the entire interface of the other phase without interruption, i.e., the development of droplets or individual fields is avoided. The phases used according to this invention are essentially not miscible with one another and thus are separate from each other. This condition is usually stable for the period of time immediately after mixing the phases until a few minutes thereafter, preferably a few hours thereafter.
A single UV filter is present in the most homogeneous possible distribution in the respective phases. Such a UVB filter may be, for example:
a salicylic acid ester, such as 2-ethylhexyl salicylate, menthyl salicylate, 4-isopropylbenzyl salicylate;
a benzophenone such as 2-hydroxy-4-methoxybenzophenone;
a 4-aminobenzoic acid ester, such as 2-ethylhexyl 4-(dimethylamino)benzoate, amyl 4-(dimethylamino)benzoate;
a 3-benzylcamphor derivative, such as 3-(4-methylbenzylidene)camphor or 3-benzylidenecamphor;
a cinnamic acid ester, such as 2-ethylhexyl 4-methoxycinnamate or isopentyl 4-methoxycinnamate; or
a benzomalonic acid ester or a triazine.
A combination with UVA filters such as dibenzoylmenthane derivatives such as 1-(4'-tert-butylphenyl)-3-(4'-methoxyphenyl)-1,3-propanedione or 1-phenyl-3-(4'-isopropylphenol)-1,3-propanedione may also be advantageous.
The above-mentioned UV filters are lipophilic and therefore are suitable for incorporation into one or more of the oily phases. These phases may preferably also contain free radical scavengers such as vitamin E.
A hydrophilic UV filter may also be incorporated into the non-oily phase to advantage. Hydrophilic UV filters include: sulfonic acid derivatives of benzophenones such as 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid and the salts thereof; 2-phenylbenzimidazole-5-sulfonic acid and the salts thereof; 3-benzylidenecamphorsulfonic acids such as 4-(2-oxo-3-bornylidenemethyl)benzenesulfonic acid, etc. and salts thereof.
The non-oily phase may advantageously contain inorganic pigments such as titanium dioxide and zinc oxide and mixtures thereof with aluminum oxide and/or silicon dioxide as UV filters. This is a special measure according to this invention that yields the advantage that the user has no problems with allergic irritation due to chemical UV filters when inorganic pigments are provided in the phase next to the skin. Titanium dioxide is especially preferred.
The particle size of the inorganic pigments is preferably less than 400 nm, especially less than 300 nm. Natural pigments such as melanin may also be used.
The sunscreen agent according to this invention will generally contain lipophilic filters in the oily phase and hydrophilic filters in the non-oily phase. With a three-layer or multi-layer composition, UV filters may also be present in one or two other phases between these oily and non-oily phases. These filters are preferably different from the neighboring phases to ensure that the UV filter provided for the intermediate phase is again present in this layer even when the phases separate after the mixing process. This type of filter may be different, depending on the filters in the neighboring phases, and is to be selected by those skilled in the art, taking into account the above factors.
Of course, several UV filters may also be present in one phase, assuming at least one other UV filter is present in a second phase.
It has surprisingly been found in the layering of several separate phases one above the other according to this invention that:
the absorption of two UV filters, each separately in a homogeneous phase (layer), is much greater than the absorption of the same filters in mixture with each other in just one phase, assuming the same concentrations;
the absorption is greater, the more homogeneously the filters are distributed and the thicker the layer;
any negative effect of the organic filters (chemical filters) on sensitive skin is prevented by the arrangement of one layer directly on the skin surface with inorganic pigments alone (so-called physical filters), and thus there are no allergic reactions;
1. this yields a reduced usage of the active ingredient (UV filter) with a separate layered composition of a sunscreen agent in comparison with the conventional emulsion, or a higher sunscreen factor is obtained with the same quantity of active ingredient;
a pleasant, soft feeling on the skin is obtained without any stickiness;
large amounts of inorganic pigments such as TiO 2 do not lead to any whitening effect, i.e., there is no white streaking on contact with water.
Another advantage of the present invention with a multilayer composition including a layer with a polymer lac is that the water resistance of the sunscreen agent is greatly improved. This is an important advance, especially for sunscreen agents, because it eliminates the repeated application of the agent to the skin when swimming in swimming pools or natural bodies of water. It has been found that a single application of the agent and repeated swimming thereafter provides protection for at least three to four hours without a single repeat application.
This invention also concerns a process for producing a sunscreen agent that is characterized in that at least two separate, essentially liquid phases, at least one of which contains a UV filter, but preferably two phases contain a UV filter, are placed in a container. The phases in the container are separate from each other in the container or are spatially separated; the phases are preferably spatially separated from each other.
"Essentially liquid phases" in the sense of the present invention is understood to refer to substances that are liquid to pasty or gelatinous and can be distributed uniformly when applied to the skin.
"Non-miscible phases" in the sense of the present invention is understood to refer to substances that are difficult or impossible to mix or spread on each other, whether with or without the addition of any additives, without forming an essential mixed phase. The condition of non-miscibility with each other and the liquids is based on the temperature range of 5° C. to 50° C., i.e., normally ambient temperature.
Phases "separate from each other" are those that form layers when layered one above the other or when mixed gently together. "Spatially separated" phases are those that are arranged without any direct contact with each other.
"Brief and gentle mixing process" is understood to be a mixing process that takes less than approximately one minute and involves essentially no application of force, e.g., by allowing the phases to flow into each other and/or by rubbing the phases on the skin.
"Spontaneously separating" is understood to mean that layers develop within seconds to less than ten minutes after a brief and gentle mixing process.
The process according to this invention for applying a sunscreen to the skin consists of mixing essentially liquid phases that are separate in a dispenser or are spatially separated, with UVA and/or UVB filters being present in at least two separate phases, in predetermined mixing ratios immediately before application and then applying them to the skin in mixed form and distributing them.
A preferred method of applying the sunscreen agent consists of briefly and gently mixing, immediately before application, essentially liquid and anhydrous phases that are spatially separated from each other in a dispenser and consist of at least:
(1) an oily phase containing a UV filter,
(2) a phase consisting of a polymer lac or a polymer film-forming compound in an organic solvent and optionally containing a UV filter,
(3) a phase containing one or more fluorocarbons and an inorganic pigment as UV filters, in predetermined mixing ratios and applying them in mixed form to the skin and distributing them there.
A dispenser for applying the sunscreen agent according to this invention may be, for example, a container that has three compartments and is or can be pressurized and contains, for example, the individual phases in predetermined quantities in these chambers. These phases are then mixed together in the desired mixing ratio in a mixing head by operating the pressure valve and are dispensed through an outlet orifice. Following this, they are distributed on the skin by the user.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention will be explained in greater detail below on the basis of examples. All percentages are based on weight (wt %) unless otherwise indicated.
The individual phases are prepared by dispersing the inorganic pigment, e.g., TiO 2 , and optionally a coloring pigment in the liquid medium for phase A. For phase B, the polymer lac or film-forming agent and optionally the chemical UV filters are added to the solvent and mixed. For phase C or other phases, chemical filters are added to the liquid oils or silicone polymers, optionally also in combination with antioxidants such as vitamin E, and mixed together.
EXAMPLE 1
The individual phases were prepared separately by mixing the respective ingredients in the manner indicated above.
______________________________________Phase APerfluorodecalin 60%Perfluoropolymethylisopropyl ether 30%(Fomblin HC)UV filter TiO.sub.2 10%Phase BShellac 1.0%UV filter benzophenone-3 2.0%(2-hydroxy-4-methoxybenzophenone)UV filter octyl methoxycinnamate 4.5%(2-ethylhexyl p-methoxycinnamate)Isopropanol QSPhase CJojoba oil 5.0%UV filter benzophenone-3 6.0%Vitamin E 1.0%UV filter octyl methoxycinnamate 5.5%Dioctyl ether QS______________________________________
The proportions of phases A, B and C in the total mixture were 35%, 20% and 45%, respectively.
EXAMPLE 2
The individual phases were prepared separately by mixing the respective ingredients in the proper manner.
______________________________________Phase APerfluorodecalin QSUV filter TiO.sub.2 8%Zinc oxide 7%Kaolin/silicon dioxide 10%Phase BShellac 3.0%UV filters, sodium and 20.0%triethanolamine salts of2-phenylbenzimidazole-5-sulfonic acidUV filter octyl methoxycinnamate 4.5%Ethanol QSPhase CJojoba oil 7.5%Isohexadecane 3.5%Vitamin E 1.0%UV filter octyl methoxycinnamate 15.5%Oxybenzone 9.5%Dioctyl ether QS______________________________________
The proportions of phases A, B and C in the total mixture were 15%, 5% and 80%, respectively.
EXAMPLE 3
The individual phases were prepared separately by mixing the respective ingredients in the proper manner.
______________________________________Phase AC.sub.12 -C.sub.15 alkyl benzoate QSUV filter TiO.sub.2 20%Phase BIsopropanol QSUV filters sodium and 10.0%triethanolamine salts of2-phenylbenzimidazole-5-sulfonic acidPhase CSilicone oil QSPoly(dimethylsiloxane) g poly(isobutyl methacrylate) 25%UV filter oxybenzone 10%UV filter octyl methoxycinnamate 5%______________________________________
The proportions of phases A, B and C in the total mixture were 30%, 20% and 50%, respectively.
EXAMPLE 4
(sunscreen as light make-up)
The individual phases were prepared separately by mixing the respective ingredients in the proper manner.
______________________________________Phase AC.sub.12 -C.sub.15 alkyl benzoate QSUV filter TiO.sub.2 5%Zinc oxide 2.5%Kaolin* 5.0%Pigmented colors for make-up 2.0%Soluble colors 1.5%Phase BShellac 0.5%Isopropanol QSUV filters sodium and triethanolamine salts 15.0%of 2-phenylbenzimidazole-5-sulfonic acidPhase CSilicone oil QSPoly(isobutyl methacrylate) co methyl FOSEA) g 20%poly(dimethylsiloxane)UV filter oxybenzone 8%______________________________________ *Kaolin with a high kaolin content and 0.5-10 wt % spherical SiO.sub.2 which has a particle size of <5 μm (according to German! patent application P 44 45 064.8).
The proportions of phases A, B and C in the total mixture were 45%, 10% and 45% , respectively.
EXAMPLE 5
(light self-tanning agent with a high sunscreen factor)
______________________________________Liposome with DNA______________________________________Lecithin 10%Dihydroxyacetone (DHA) 10%Ethanol 7%Water QS______________________________________
The dihydroxyacetone is dissolved in water and stirred into lecithin. Then ethanol is stirred in and the entire mixture is homogenized well.
______________________________________Phase APerfluorodecalin QSTiO.sub.2 8%Phase BIsopropanol QSShellac 1.5%UV filters sodium and triethanolamine salts 10.0%of 2-phenylbenzimidazole-5-sulfonic acidPhase CPPG isostearyl ether QSUV filter butylmethoxydibenzoylmenthane 5.0%4-methoxybenzylidenecamphor 8.0%Dihydroxyacetone liposome 10.0%______________________________________
EXAMPLE 6
______________________________________Phase APerfluorodecalin QSTiO.sub.2 8%Melanin 1%Phase BEthanol QSShellac 1.5%Sodium and triethanolamine salts of 15%2-phenylbenzimidazole-5-sulfonic acidPhase CJojoba oil QSIsohexadecane 3%Oxybenzone 10%Octyl methoxycinnamate 15%Melanin, soluble 3%______________________________________
The proportions of phases A, B and C in the total mixture were 35%, 15% and 50%, respectively.
EXAMPLE 7
(make-up with self-tanning agent and a high sunscreen factor)
______________________________________Phase AC.sub.12 -C.sub.15 alkyl benzoate QSUV filter TiO.sub.2 5%Zinc oxide 1.5%Kaolin* 4.5%Pigmented colors for make-up 2.0%Soluble colors, depending on tint 1.0%Melanin 1.0%DHA liposome according to Example 5 10%Phase BShellac 1.0%Isopropanol QSSodium and triethanolamine salts 15%of 2-phenylbenzimidazole-5-sulfonic acidPhase CSilicone oil QSPoly(isobutyl methacrylate) co methyl FOSEA) g 20%poly(dimethylsiloxane)Oxybenzone 8%Vitamin E 1%Melanin, soluble 1.5%______________________________________
EXAMPLE 8
Three mg of an oily phase (based on a linoleate) per cm 2 of skin were applied to ten volunteers. This phase contained 2% octyl methoxycinnamate (OMC) as a UV filter. Over this was applied 1 mg/cm 2 of an aqueous phase. The aqueous phase contained 3% Tio 2 , so that 4 mg/cm 2 contained a total of 0.14 mg OMC/cm 2 and 0.2 mg TiOVEIL AQN/cm 2 . According to measurement of the sunscreen factor by the Diffey method, an average sunscreen factor of 7.03 was obtained.
Comparative Example 1
A comparative emulsion was applied to ten volunteers in the amount of 4 mg/cm 2 . The emulsion contained 1% titanium dioxide filter and 1.5% of the OMC filter. This comparative emulsion thus contained the same amount of UV filter as the two layers in Example 8 together. According to measurement of the sunscreen factor by the Diffey method, an average value of 4.97 was obtained.
The comparison shows clearly that even a two-layer arrangement of sunscreen agents permits a significant improvement in comparison with the known emulsions.
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A multi-phase sunscreen agent, characterized by at least two phases that are liquid to pasty or gelatinous and separate from each other spontaneously within seconds to less than ten minutes after a brief and gentle mixing process lasting less than one minute without any essential application of force, where at least one phase contains a UV filter.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pressure control valve for a direct-injection fuel system of an internal combustion engine, having a valve housing, at least one inlet, at least one outlet, and at least one prestressed, electrically actuatable, and at least regionally spherical valve member, which cooperates with a valve seat structurally connected to the housing.
2. Description of the Prior Art
One pressure control valve of the type which the invention is concerned is known from European Patent Disclosure EP 0 267 162. In this known pressure control valve, a valve ball is seated on the end of an inlet conduit that accordingly forms a valve seat. The ball is pressed against this valve seat by a valve tappet that is acted upon by a spring. Fastened to the end of the valve tappet remote from the ball is a magnet armature, which is surrounded by an annular electromagnet. When the magnet coil is not excited, the contact-pressure force of the valve ball is effected solely by the force of the spring. Upon an excitation of the magnet coil, the magnetic force is superimposed on this. The superposition takes place in the direction of the spring force, so that depending on the intensity of the magnetic force, the closing pressure of the valve can be increased beyond what the spring alone can exert.
However, in the known pressure control valve it has been found that the quality of the pressure control does not always meet the demands made of it. In particular, it has been demonstrated that the known pressure control valve tends to high-frequency fluttering under some circumstances.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to refine a pressure control valve of the type defined at the outset such that in a simple way, it can be operated reliably and makes stable pressure control possible.
In a pressure control valve of the type defined at the outset, this object is attained in that the valve seat widens conically toward the valve member, and the ball diameter of the valve member is selected such that with the valve closed, the valve member touches the valve seat in the vicinity of the further end of the valve seat.
According to the invention, it has been recognized that the flow downstream of the point of passage between the valve seat and the valve member can be calmed or stabilized if the flow is carried radially outward through a conical widening of the valve seat. This additionally requires, however, that the narrowest point of the passageway gap between the valve member and the valve seat be located as close as possible to the farther, that is, the downstream, end of the valve seat. In such an embodiment of the valve seat and the valve member, a relatively calm, stable, radially outward-oriented flow downstream of the point of passage through the valve gap is obtained when the valve is open.
This in turn makes markedly improved quality of the open- or closed-loop control of the fuel pressure in a fuel system possible. This makes more-accurate metering of the fuel upon injection, for instance into a combustion chamber of the engine, possible, which in turn improves the fuel consumption and emissions properties of the engine. The improvement in the open- and closed-loop control quality is achieved without requiring additional components or complex machining steps. Thus the pressure control valve of the invention can be produced relatively inexpensively.
In a first refinement of the invention it is proposed that the prestressing force is adjustable, in particular by means of a spring that can be tensed by a screw. In this way, the mechanical opening pressure for each pressure control valve can be adjusted in an especially simple way.
It is also possible that the valve member is embodied as a ball, and a retaining element is provided, in which the ball is retained transversely to the actuation direction. By means of such a retaining element, it is assured that even with the valve open, that is, when the valve member is lifted from the valve seat, the annular gap between the valve member and the valve seat is approximately the same size throughout. This prevents lateral differences in pressure at the annular gap, which under circumstances could cause a lateral oscillating motion of the valve member.
It is especially preferred if the retaining element has at least three radially inward-oriented retaining tongues, each with at least one radially inner wall on which the ball rests. With such retaining tongues, an unambiguous centering of the valve member relative to the valve seat is possible, without the passage of fluid being severely impaired by the retaining element.
In an especially preferred refinement, the pressure control valve of the invention includes a valve tappet, which acts upon the valve member. In addition, at least two plastic slide bushes are provided, in which the valve tappet is retained in an axially sliding fashion. Because of such minimally frictional or even frictionless bearing support of the valve tappet, the adjustment characteristic of the valve tappet has a slight hysteresis, which contributes to fine pressure adjustment by the pressure control valve.
The triggering of the pressure control valve can be effected in an especially simple way by providing that it is actuatable electromagnetically, and at least one magnet armature is retained on the valve tappet via a compression connection.
It is also especially preferred if the pressure control valve includes a magnet core, extending coaxially to the valve tappet, on which core one of the plastic slide bushes is secured, and the plastic slide bush, toward the armature, has a shoulder which serves as a spacer between the magnet core and the armature. The shoulder assures that even with the armature attracted, a remanent air gap required for the magnetic action is always available between the magnet core and the armature. Providing a magnet core leads to a boost in the magnetic action, which improves the dynamics of the pressure control valve of the invention. Disposing the plastic slide bush on the magnet core makes a separate retaining part unnecessary, which reduces the production cost for the pressure control valve of the invention.
According to the invention, a hydraulic module can also be provided, which includes the valve housing, the inlet, the outlet, the valve member, the valve seat, the prestressing element, the valve tappet, the armature, the magnet core, and the plastic slide bushes, and a coil module can be provided, which includes at least one magnet coil, extending coaxially to the magnet armature, as well as an electrical terminal, and the hydraulic module and coil module form separate component groups from one another.
This refinement of the pressure control valve of the invention has the advantage that the hydraulic module and the coil module can be produced separately from one another, which lowers the production costs because of the different production requirements. In the case of a defect, it is possible to replace the individual modules separately. Furthermore, a separate coil module makes it possible for different coil modules, equipped with the terminals to suit customer requirements, each to be combined with the same hydraulic module. Once again, this reduces the production cost for the pressure control valve of the invention, since at least for the hydraulic module, relatively large numbers are manufactured.
Connecting the hydraulic module to the coil module is preferably done via a frictional-engagement and/or detent connection. This also creates a means of securing it for shipping, which prevents parts located on the inside from becoming soiled or damaged. The fact that the frictional-engagement and/or detent connection can be disconnected again makes easy replacement of the parts possible.
In another refinement, it is proposed that the coil module includes an approximately U-shaped bracket element, which as its base has a fastening portion with at least two laterally protruding retaining flanges and as its legs has at least two striplike encapsulation portions, which fit over the coil from outside. With the U-shaped bracket element, the pressure control valve of the invention can thus be fastened in a simple way to some element of the fuel system. At the same time, the bracket element makes a boost in the magnetic force possible, by a laterally outer encapsulation of at least one region of the magnet coil.
It is especially preferred if the bracket element, on the ends of the legs, has fastening portions, in particular detent lugs, to which a cap element can be secured, in particular calked, with which cap element the coil is magnetically encapsulated on its end. The terminal encapsulation of the coil boosts the magnetic force still further, and the retention of the applicable cap is accomplished in a simple way by the bracket element.
It is also possible that the valve housing has a laterally outward-pointing shoulder, which rests on the bracket element. In this way, there is no need for separately fastening the hydraulic module to the coil module of the built-in pressure control valve, since in the built-in position, the hydraulic module is pressed with its shoulder against the coil module by the hydraulic pressure.
To further increase the magnetic force, it is proposed that there is a gap between the valve housing and the magnet core, and the valve housing is joined to the magnet core via a ring of an antimagnetic material.
In another preferred refinement of the pressure control valve of the invention, a receiving part with a stepped bore is provided, into which bore a connection peg of the valve housing is inserted, and an inlet-side line discharges into one portion of the stepped bore while an output-side line discharges into another portion, and the inlet-side line is sealed off from the outlet-side line by a first ring seal, and the outlet-side line is sealed off from environment by a second ring seal, and the second ring seal has a larger diameter than the first ring seal, and in the built-in state, the spacing between the first ring seal and the first step of the stepped bore is less than the spacing between the second ring seal and the second step, leading to the environment, and the fastening of the valve housing to the receiving part is elastic in the axial direction. This refinement of the pressure control valve of the invention is based on the following consideration:
Should the valve member become wedged in its closing position because of a defect, this means that the pressure limiting function of the pressure control valve is no longer operative. In that case, because of the axially elastic fastening of the valve housing to the receiving part, the valve housing and as a result the entire pressure control valve can be pushed out of the receiving part or out of the stepped bore as the hydraulic pressure increases.
If the inlet and outlet and the corresponding ring seals are embodied as claimed, it is assured that whenever the connection peg moves axially out of the receiving part, first the ring seal between the inlet and the outlet slips over the corresponding step, thus establishing a direct communication between the inlet and the outlet. In this way, virtually the entire pressure control valve acts as a valve element, which with increasing hydraulic pressure is lifted from its valve seat, namely the stepped bore. Thus even if the valve member is blocked, a certain pressure limiting function of the pressure control valve is assured.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings, in which:
FIG. 1 is a basic illustration of a fuel system with a pressure control valve;
FIG. 2 shows a longitudinal section through the pressure control valve of FIG. 1;
FIG. 3 is a section taken along the line III—III of FIG. 2;
FIG. 4 shows a detail of the injection valve in FIG. 2;
FIG. 5 is a longitudinal section through a region of the pressure control valve of FIG. 1 and of a receiving part;
FIG. 6 shows a retaining element for a valve member of the pressure control valve of FIG. 1 in perspective;
FIG. 7 is a plan view on the retaining element of FIG. 6;
FIG. 8 is a perspective view of a blank from which a bracket element of the pressure control valve of FIG. 1 is made; and
FIG. 9 shows the bracket element made from the blank of FIG. 8 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A fuel system is identified overall in FIG. 1 by reference numeral 10 . It includes a fuel tank 12 , from which fuel is pumped via a fuel line 14 by an electric fuel pump 16 to a filter 18 and from there to a high-pressure pump 20 . The pressure in the fuel line 14 is regulated by a low-pressure regulator 22 , which is disposed in a branch line 24 .
From the high-pressure pump 20 , a high-pressure fuel line 26 leads to a fuel collection line 28 , called a “rail”. Connected to the rail, in the present exemplary embodiment, are four high-pressure injection valves 30 . By way of these valves, the fuel is injected directly into a combustion chamber, not shown, of an internal combustion engine, also not shown. The pressure in the rail 28 monitored up by a pressure sensor 32 .
The adjustment of the pressure in the rail 28 is effected by a pressure control valve 34 , which communicates on its inlet side with the rail 28 via a fuel line 36 and on the outlet side with the low-pressure fuel line 14 via a fuel line 38 . By means of the pressure control valve 34 , the pressure in the rail 28 can be adjusted within a range of approximately 4 to 130 bar. To that end, the pressure control valve 34 is triggered by an open- and closed-loop control unit, not shown. This unit in turn receives signals from the pressure sensor 32 . Adjusting the pressure in the rail 28 can be done by means of a closed control loop or by simple triggering of the pressure control valve 34 .
The pressure control valve 34 will now be described in detail, referring to FIGS. 2-9 (for the sake of simplicity, not all the reference numerals are shown in FIG. 3 ):
First, the pressure control valve 34 includes a cylindrical valve housing 40 which in its lower region in FIGS. 2 and 3, together with a valve body 43 forms a connection peg 42 . Extending coaxially in this connection peg 42 is an inlet conduit 44 , embodied as a stepped bore. Above the inlet conduit 44 are two radially extending outlet conduits 46 (in another exemplary embodiment, not shown, there is only one outlet conduit; more than two outlet conduits are equally conceivable). The inlet conduit 44 and the outlet conduits 46 communicates with a flow chamber 48 in the interior of the connection peg 42 . A filter piece is mounted on the free end of the connection peg 42 . Approximately in its center axially, the valve housing 40 has an encompassing, radially outward-pointing annular rib 51 .
The stepped bore of the inlet conduit 44 narrows axially from the outside inward. However, a conical widened portion 50 (see FIG. 4) is also present on the upper end of the uppermost portion, in FIG. 2, of the inlet conduit 44 . This widened portion forms a valve seat for a valve ball 52 . The diameter of the valve ball 52 is selected such that whenever the valve ball 52 rests on the valve seat 50 , the valve ball 52 touches the valve seat 50 in the vicinity of its farther or in other words upper end in FIGS. 2-4.
The valve ball 52 is retained radially of the connection peg 42 by a retaining element 54 . The retaining element has a triangular outer contour, with rounded corners. An also approximately triangular recess 56 , again with rounded corners, is present in the center of the retaining element 54 . From the centers of the sides of the triangle of the recess 56 , retaining tongues 58 extend radially inward, and the radially inner wall of the retaining tongues in each case is identified by reference numeral 60 . The valve ball 52 rests on these radially inner walls 60 of the retaining tongues 58 . In this way, the valve ball 52 is retained transversely to the actuation direction by the retaining tongues 58 . The retaining element 54 has a generally disklike shape and is inserted into an axial recess in the top side of the valve body 43 .
The upper boundary wall of the flow chamber 48 is pierced by a bore 62 , into which a first plastic slide bush 64 is inserted. A valve tappet 66 embodied as a cylindrical pin is supported with little friction in the first plastic slide bush 64 . Above the flow chamber 48 in the valve housing 40 , there is a further coaxial, cylindrical recess 68 , which is open at the top. A cylindrical magnet armature 70 is pressed onto the valve tappet 66 . The lower end face of the magnet armature is spaced apart from the lower end face of the recess 68 . With its upper end, the magnet armature 70 protrudes past the upper end of the valve housing 40 .
An annular element 72 made of an antimagnetic material is welded onto the outer jacket face, on the upper end of the valve housing 40 . The annular element 72 likewise protrudes past the upper end of the valve housing 40 and is welded at its upper end to a magnet core 74 that extends coaxially to the valve housing 40 . The outside diameter of the magnet core 74 is approximately equivalent to the outside diameter of the upper portion of the valve housing 40 .
The magnet core 74 has a bore 76 that extends over its full length. The through bore 76 is likewise embodied in stepped fashion. A second plastic slide bush 78 is inserted into the lowermost portion of this bore in terms of FIGS. 2 and 3. With a shoulder 79 , the plastic slide bush 78 protrudes somewhat past the base of a countersunk feature 80 in the underside of the magnet core 74 . The diameter of the countersunk feature 80 is somewhat greater than the diameter of the magnet armature 70 . The shoulder 79 forms a spacer for the armature 70 . The upper end, in terms of FIGS. 2 and 3, of the valve tappet 66 is supported with little friction in the second plastic slide bush 78 .
A spring holder 82 is fastened to the upper end of the valve tappet 66 . The spring holder, on its end toward the valve tappet 66 , has a head 84 , on which a compression spring 86 is braced. The compression spring 86 extends upward coaxially to the valve tappet 66 and is guided by an upward-extending guide portion 88 of the spring holder 82 . The upper end of the spring 86 is in turn braced on an adjusting screw 90 . This screw is screwed into the magnet core 74 in a threaded portion 92 in the upper region of the through bore 76 .
The adjusting screw 90 is sealed off from the through bore 76 by an O-ring seal 94 . By means of the adjusting screw 90 , the prestressing force of the spring 86 can be adjusted. The prestressing force of the spring 86 is transmitted via the valve tappet 66 to the valve ball 52 , and as a result the valve ball is pressed against the valve seat 50 .
The valve housing 40 , the valve body 43 with the inlet conduit 44 and the outlet conduits 46 , the valve ball 52 and the associated valve seat 50 , the compression spring 86 , the valve tappet 66 , the plastic slide bushes 64 and 78 , the magnet armature 70 , the magnet core 74 , the spring holder 82 and the adjusting screw 90 together form a hydraulic module 96 that forms a cohesive component group.
To generate a magnetic force, first an annular winding holder 98 is provided. This winding holder is disposed coaxially to the valve housing 40 and surrounds the upper region of the valve housing 40 as well as the lower region of the magnet core 74 . Winding wire is wound onto the winding holder 98 , forming a coil 99 . On its lower end, the winding holder 98 has a radially inner collar 100 , which protrudes axially downward and with its edge rests on the bracket element 102 and is spray-coated.
The bracket element 102 is shown in detail in FIGS. 8 and 9. It is stamped out as a flat part (FIG. 8) and then, by bending two legs 104 upward, shaped into a U-shaped part. There is a circular recess 108 in a base 106 of the bracket element 102 , the inside diameter of which recess is approximately equivalent to the outside diameter of the upper portion of the valve housing 40 . Two retaining flanges 110 protrude laterally from the base 106 , and in each of the retaining flanges there are respective fastening bores 112 .
The legs 104 of the bracket element 102 form striplike encapsulation portions, which fit from outside over the winding holder 98 with the coil 99 wound onto it. Detent lugs 114 are embodied on the ends of the legs 104 and are calked to a platelike cap element 116 . The cap element 116 likewise has a central recess 118 , whose diameter is approximately equivalent to the outside diameter of the magnet core 74 . By means of the bracket element 102 and the cap element 116 , an external encapsulation of the coil 99 on the winding holder 98 is created.
The coil 99 on the winding holder 98 is connected to a radially protruding flat plug 120 . The bracket element 102 , cap element 116 , flat plug 120 and winding holder 98 with the coil 99 are entirely sheathed with plastic 122 . The winding holder 98 with the coil 99 , the bracket element 102 , the cap element 116 , the flat plug 120 and the molded plastic sheath 122 together form a coil module 124 embodied as a separate component.
The joining of the coil module 124 to the hydraulic module 96 is effected simply by slipping the coil module 124 onto the hydraulic module 96 until the base 106 of the bracket element 102 rests on the annular shoulder 51 of the valve housing 40 . The coil module 124 is prevented from slipping off the hydraulic module 96 by detent lugs 126 , which are embodied in the upper region of the magnet core and dig into the molded plastic sheath 122 . Because the pressure control valve 34 has both a hydraulic module 96 , embodied as a separate component group, and a coil module 124 , also embodied as a separate component group, it is possible to connect the hydraulic module 96 to different coil modules 124 .
This in turn makes it possible to produce the hydraulic module 96 in very large numbers, which reduces its production costs. The coil module, which is relatively simple to produce, can in turn be equipped to meet specific customer requirements, for instance being equipped with a special flat plug 120 . In the case of a defect, the coil module 124 can simply be pulled off the hydraulic module 96 , which makes the central components of the hydraulic module 96 easily accessible so they can be checked and if needed repaired.
As can be seen from FIG. 5, the pressure control valve 34 can be inserted, with the connection peg 42 of the valve housing 40 leading, into a stepped bore 128 of a receiving part 130 . The receiving part 130 can be disposed at various places in the fuel system 10 . For instance, it is possible for it to be present directly on the rail 28 . However, mounting it directly on the high-pressure pump 20 is also conceivable.
The receiving part 130 can be provided as a separate part or can be embodied integrally with the rail 28 or the housing of the high-pressure pump 20 . The fuel line on the input side, embodied in the receiving part 130 , is identified by reference numeral 36 as in FIG. 1, while conversely the fuel line on the output side is identified by reference numeral 38 . The pressure control valve 34 is secured to the receiving part 130 via the retaining flanges 110 , shown only in part in FIG. 5 . The hydraulic module is pressed by the fuel pressure with its annular rib 51 against the bracket element 102 .
The pressure control valve 34 functions as follows: If the magnet unit, formed by the coil 99 and the winding holder 98 , is not excited, the opening pressure of the pressure control valve 34 is determined solely by the prestressing force of the spring 86 . If the applicable limit pressure is exceeded, the valve ball 52 is lifted from the valve seat 50 because of the pressure difference between the inlet conduit 44 and the flow chamber 48 . As a result, fuel from the inlet-side line 36 and the inlet conduit 44 passes through the gap between the valve seat 50 and the valve ball 52 to reach the flow chamber 48 , and it can flow out into the outlet-side line 38 via the outlet conduits 46 .
Because the valve seat 50 is embodied as a conical widened portion, and the passageway gap for the fuel between the valve ball 52 and the valve seat 50 is located in the region of the farther end of the valve seat 50 , upon opening of the pressure control valve 34 a stable flow state is achieved, making the quality of closed- and open-loop control of the pressure control valve 34 optimal. Lateral oscillating motions of the valve ball 52 are reliably prevented by the retaining element 54 with the retaining tongues 58 .
To make a different opening pressure of the pressure control valve 34 possible, electric current is delivered to the coil 99 . Depending on the type and intensity of the current delivered, the magnet core 74 exerts a force on the magnet armature 70 . This force is superimposed on the prestressing force furnished by the spring 86 . Because the magnet core 74 exerts a force of attraction on the magnet armature 70 , the contact pressure exerted by the valve tappet 66 on the valve ball 52 decreases, so that the valve ball 52 is pressed with a lesser force against the valve seat 50 . As a result, the opening pressure of the pressure control valve 34 is lowered. In this way, different pressures in the rail 28 can be established. A lowering of the rail pressure to approximately 4 bar is possible. This is equivalent to the pressure that typically prevails in the fuel line 14 .
The shoulder 79 , acting like a spacer, of the plastic slide bush 78 assures that even if the magnet armature 70 is completely attracted, a remanent air gap required for the magnetic action will always be present between the magnet armature 70 and the magnet core 74 . The magnetic decoupling between the valve housing 40 and the magnet core 74 is assured by the antimagnetic ring element 72 . By means of the slide bushes 64 and 78 , the valve tappet is supported with little friction, so that upon actuation it exhibits only slight hysteresis—if any.
Yet even if the valve ball 52 , for whatever reasons, is blocked on the valve seat 50 , or in other words opening of the pressure control valve 34 is not possible, the pressure control valve 34 can still provide an “emergency pressure limiting function”. This is accomplished as follows:
As seen particular from FIG. 5, the connection peg 42 of the valve housing 40 has two ring seals 132 and 134 on its outside. FIG. 5 also shows that between the portion of the stepped bore 128 of smaller diameter in the receiving part 130 and the portion thereof of larger diameter, there is a step 136 , embodied as an insertion chamfer. The region of larger diameter of the stepped bore 128 likewise has an insertion chamfer 138 on its upper end. The lower ring seal 132 in terms of FIG. 5 assures sealing between the inlet-side line 36 and the outlet-side line 38 , while conversely the upper ring seal 134 in FIG. 5 assures sealing between the outlet-side line 38 and the environment. The lower ring seal 132 has a smaller diameter, adapted to the diameter of the corresponding portion of the stepped bore 128 , than the upper ring seal 134 .
If the pressure in the inlet-side line 36 now rises, and if because of a jammed valve ball 52 this pressure increase cannot be diverted via the inlet conduit 44 , flow chamber 48 and outlet conduits 46 to the outlet-side line 38 , then because of the differential pressure between the inlet-side line 36 and the environment, the entire pressure control valve 34 is pushed somewhat out of the stepped bore 128 in the receiving part 130 . This is possible because the retaining flanges 110 of the bracket element 102 have a certain elasticity in the axial direction of the pressure control valve 34 .
Since as FIG. 5 shows the spacing between the lower ring seal 132 and the insertion chamfer 136 is less than the spacing between the upper ring seal 134 and the insertion chamfer 138 , when the pressure control valve 34 moves axially upward it is the lower ring seal 132 that first reaches the region of the insertion chamfer 136 , while conversely the upper ring seal 134 still remains in the region of the larger-diameter portion of the stepped bore 128 .
However, if the lower ring seal 132 reaches the region of the insertion chamfer 136 , the sealing action between the ring seal 132 and the wall of the stepped bore 128 lessens, so that fuel can flow directly from the inlet-side line 36 past the ring seal 132 to reach the outlet-side line 38 , circumventing the pressure control valve 34 . In that case, the entire pressure control valve 34 together with the lower ring seal 132 accordingly acts as a valve member, and the stepped bore 128 in the receiving part 130 acts as a valve seat. The retaining flanges 110 on the bracket element 102 act as a prestressing element.
In this way, pressure from the inlet-side line 36 can be let off into the outlet-side line 38 even whenever the pressure control valve 34 is no longer functioning properly. Thus it remains assured that no fuel will reach the environment.
In closing, it should be pointed out that the terms “lower” and “upper” used in the description of the present exemplary embodiment pertain to the disposition of the pressure control valve 34 in FIGS. 1-9. It is understood that the pressure control valve 34 can be installed in an arbitrary position in a fuel system 10 . However, preferably it is installed in a more or less upright position, to avert the problem of soiling and icing up during operation of the pressure control valve.
The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
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A pressure control valve serves to regulate the fuel pressure in a fuel system. The pressure control valve includes a valve housing, at least one inlet, at least one outlet, and at least one prestressed, electrically actuatable, and at least regionally ball-shaped valve member. The valve member cooperates with a valve seat structurally connected to the housing. To make it possible to achieve stable closed- and/or open-loop control properties of the pressure control valve, it is proposed that the valve seat widen conically toward the valve member, and the ball diameter of the valve member is selected such that with the valve closed, the valve member touches the valve seat in the vicinity of its farther end.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of U.S. Provisional Patent Application No. 60/747,929, filed on May 22, 2006, which application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates apparatus and methods for drilling and completing a wellbore. Particularly, the present invention relates to apparatus and methods for forming a wellbore, lining a wellbore, and circulating fluids in the wellbore. The present invention also relates to apparatus and methods for cementing a wellbore.
[0004] 2. Description of the Related Art
[0005] In the drilling of oil and gas wells, a wellbore is formed using a drill bit that is urged downwardly at a lower end of a drill string. After drilling a predetermined depth, the drill string and bit are removed, and the wellbore is lined with a string of casing. An annular area is thus defined between the outside of the casing and the earth formation. This annular area is filled with cement to permanently set the casing in the wellbore and to facilitate the isolation of production zones and fluids at different depths within the wellbore.
[0006] It is common to employ more than one string of casing in a wellbore. In this respect, a first string of casing is set in the wellbore when the well is drilled to a first designated depth. The well is then drilled to a second designated depth and thereafter lined with a string of casing with a smaller diameter than the first string of casing. This process is repeated until the desired well depth is obtained, each additional string of casing resulting in a smaller diameter than the one above it. The reduction in the diameter reduces the cross-sectional area in which circulating fluid may travel. Also, the smaller casing at the bottom of the hole may limit the hydrocarbon production rate. Thus, oil companies are trying to maximize the diameter of casing at the desired depth in order to maximize hydrocarbon production. To this end, the clearance between subsequent casing strings having been trending smaller because larger subsequent casings are used to maximize production.
[0007] Drilling with casing or liner is a method of forming a borehole with a drill bit attached to the same string of tubulars that will line the borehole. In other words, rather than run a drill bit on smaller diameter drill string, the bit is run at the end of larger diameter tubing or casing or liner that will remain in the wellbore and be cemented therein. The advantages of drilling with casing are obvious. Because the same string of tubulars transports the bit and lines the borehole, no separate trip out of or into the wellbore is necessary between the forming of the borehole and the lining of the borehole. Drilling with casing or liner is especially useful in certain situations where an operator wants to drill and line a borehole as quickly as possible to minimize the time the borehole remains unlined and subject to collapse or the effects of pressure anomalies, and mechanical instability.
[0008] In the drilling of offshore wells or deep wells, the length of casing or liner may be shorter than the water depth. Also, in some instances, the wellbore may be formed in stages, such as installing casing and thereafter hanging a liner from the casing. In both cases, the length of casing may not extend back to surface.
[0009] There is a need, therefore, for running a length of drill casing or liner into the hole to form the wellbore.
SUMMARY OF THE INVENTION
[0010] In one embodiment, a drilling apparatus includes a liner as a portion of the drill string. The axial and torsional loads are carried by the drill pipe and then transferred to the drilling liner by the use of a liner drilling tool. The forces are then transmitted along the liner to a latch. The loads are then transferred from the liner to the latch and attached BHA. The drilling apparatus may include an inner string that connects the liner drilling tool at the liner top to the BHA. This way, when the liner drilling tool and latch are disconnected from the liner, the drill pipe can pull the inner string and BHA from the liner and bore hole. In one embodiment, releasing and pulling the liner drilling tool also releases and pulls the BHA out of hole with the inner string. The inner string can also act as a conduit for fluid flow from the drillpipe to the BHA below. It should be noted that the fluid flow could be split between the inner string and the liner ID, or diverted so the entire flow is in the annulus between the inner string and the liner ID.
[0011] In another embodiment, a method of forming a wellbore includes running a liner into the wellbore; suspending the liner at a location below the rig floor; running a drilling bottom hole assembly through the liner on a drill string; attaching the drill string to the liner; releasing the liner from its location of suspension; and advancing the liner through the wellbore on the drill string.
[0012] The present invention relates methods and apparatus for lining a wellbore. In one embodiment, a method of forming a wellbore includes running liner drilling assembly into the wellbore, the liner drilling assembly including a liner, a conveying member, one or more connection members, and a drilling member. The method includes temporarily suspending the liner at a location below the rig floor; releasing the conveying member and the drilling member from the liner; re-connecting the conveying member to the liner; releasing the liner from its location of temporary suspension; and advancing the liner drilling assembly.
[0013] In another embodiment, an apparatus for forming a wellbore includes a liner coupled to a drilling member; a conveying member releasably connected to the liner, the conveying member adapted to supply torque to the liner; a first releasable and re-settable connection members for coupling the conveying member to the liner; and a second connection member for coupling the liner to the drilling member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, 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 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.
[0015] FIG. 1 shows an embodiment of the liner drilling system according to aspects of the present invention.
[0016] FIG. 2 shows an embodiment of the liner drilling system with the liner top suspended from a blow-out prevent ram.
[0017] FIG. 3 shows another embodiment of a liner drilling assembly.
[0018] FIGS. 4-8 shows the liner drilling assembly of FIG. 3 in operation.
[0019] FIG. 9 shows another embodiment of a liner drilling assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] In one embodiment, a drilling apparatus includes a liner as a portion of the drill string. The axial and torsional loads are carried by the drill pipe and then transferred to the drilling liner by the use of a liner drilling tool. The forces are then transmitted along the liner to a latch. The loads are then transferred from the liner to the latch and attached BHA. The drilling apparatus may include an inner string that connects the liner drilling tool at the liner top to the BHA. This way, when the liner drilling tool and latch are disconnected from the liner, the drill pipe can pull the inner string and BHA from the liner and bore hole. In one embodiment, releasing and pulling the liner drilling tool also releases and pulls the BHA out of hole with the inner string. The inner string can also act as a conduit for fluid flow from the drill pipe to the BHA below. It should be noted that the fluid flow could be split between the inner string and the liner ID, or the fluid flow can be fully diverted to the annulus area between the inner string OD and the liner ID. In one embodiment, the fluid returning to the surface may flow through the annular area between the wellbore and the outer diameter of the liner and/or the annular area between the inner diameter of the liner and the outer diameter of the inner string.
[0021] FIG. 1 shows an embodiment of a drilling with liner assembly of the present invention. As shown, the drilling liner assembly 100 extends below a previously installed casing 10 . The drilling liner assembly 100 is run in on drill pipe 110 . A liner drilling tool 116 is used to connect the drill pipe 110 to the liner 120 . The liner drilling tool 116 may be a component of the liner top assembly 115 , which may also include a liner hanger 117 and a polished bore receptacle (“PBR”). In one embodiment, the liner drilling tool 116 functions as a running tool for connecting the drill pipe 110 to the liner 120 . The running tool may include a latch and/or gripping members that may releasably attach and detach from the liner 120 . The running/drilling tool is adapted to transmit axial and torsional forces from the drill pipe 110 to the liner 120 . The running tool may be released from the liner 120 so that the BHA may be retrieved. Preferably, the running tool has torque capability that equals or exceeds the drill pipe capability and is adapted to endure typical bore hole drilling dynamics. Exemplary running tools are disclosed in U.S. Pat. Nos. 5,613,567, 5,531,273, and 6,032,734, which patents are incorporated herein by reference in their entirety. The liner top equipment (liner hanger and PBR) may also include large radial clearance for cuttings bypass and reduced equivalent circulating density (“ECD”) and setting of liner hanger does not reduce the annular clearance area significantly. In one embodiment, setting of the liner hanger and release of drilling tool may be independent of the differential pressure between the inside of the tool and the outside of the liner to prevent premature activation. In another embodiment, the liner top assembly is not equipped with a packer. In yet another embodiment, the liner top assembly utilizes an expandable liner hanger.
[0022] An inner string 130 extends from the liner running/drilling tool 116 to a drilling latch 140 below. The inner string 130 may be used to convey fluid from the drill pipe 110 and/or to retrieve the BHA. Also, it should be noted that fluid may be conveyed outside of the inner string, inside of the inner string, or the flow split between both. The drilling latch 140 is adapted to releasably connect to the liner 120 . An exemplary drilling latch is disclosed in U.S. Patent Application Publication No. 2004-0216892, filed on Mar. 5, 2004 by Giroux et al. having Ser. No. 10/795,214, entitled Drilling With Casing Latch, which application is herein incorporated by reference in its entirety. The drilling latch 140 is adapted to transfer axial and torsional forces from the liner 120 to the bottom hole assembly (“BHA”). The drilling latch 140 may be hydraulically, mechanically, or remotely actuated. Suitable actuating mechanism includes mud pulse technology, wire line, and fiber optics.
[0023] As shown in FIG. 1 , the bottom hole assembly includes one or more stabilizers 155 , a motor 160 , an under-reamer 165 , MWD/LWD 170 , rotary steerable systems 175 , and a drill bit 180 . It must be noted that the BHA may include other components, in addition to or in place of the above items, such as other geophysical measurement sensors, stabilizers such as eccentric or adjustable stabilizers, steerable systems such as bent motor housing, other drill bits such as expandable bit or bits having nozzles or jetting orifices for directional drilling, or any other suitable component as is known to a person of ordinary skill in the art. Further, the components of the BHA may be arranged in any suitable order as is known to a person of ordinary skill in the art. For example, the under-reamer may be place below the motor and MWD/LWD tool.
[0024] In operation, the liner drilling tool 116 and the drilling latch 140 are actuated to engage the liner 120 . The liner drilling assembly 100 is then run-in to the hole using drill pipe 110 . The liner drilling assembly 100 is directionally steered to drill the hole. In this respect, the hole may be drilled and lined in the same trip. The directional steering is performed using the rotary steerable system 175 . The axial and torsional forces are transferred from the drilling pipe 110 to the liner 120 through the liner running tool 116 and are then transferred from the liner 120 to the BHA through the drilling latch 140 . In this respect, the inner string 130 experiences little, if any, torque that is transmitted. The inner diameter of the hole may be enlarged using the under-reamer 165 . The liner drilling assembly 100 is advanced until total depth is reached. One advantage of the liner drilling assembly is that the liner protects the drilled hole during drilling. After reaching total depth, the liner hanger 117 is set to connect the liner 120 to the previously set casing. Then, the liner running tool 116 and the drilling latch 140 are released to detach from the liner 120 and are removed from the wellbore, thereby removing the BHA. In one embodiment, setting of the liner hanger 117 triggers the release of the liner running tool 116 . After the BHA is retrieved, a cement operation may be performed.
[0025] In one embodiment, a cement retainer valve is tripped in and installed in the liner to enable cementing from the liner bottom. Thereafter, a conventional cementing operation may be performed. In the situation where cement cannot be circulated, a bottom squeeze may be performed. Thereafter, a second squeeze may be performed at the liner top and the liner top packer may be set in another trip into the hole.
[0026] In some circumstances, the BHA may become inoperable before total depth is reached and the BHA must be repaired or replaced. In one embodiment, the liner 120 is left in the hole and the liner drilling tool 116 and the drilling latch 140 are released. Then, the BHA is pulled out of the hole. After the BHA is repaired or replaced, the BHA is run-in to the hole and the liner drilling tool 116 and the drilling latch 140 are actuated to re-engage the liner 120 . Thereafter, the drilling operation may continue by applying rotational and axial forces to the BHA. One or more BHAs may be replaced by repeating this process. It must be noted that in this embodiment, a possibility exists that the liner may become stuck during the time it takes to trip the new BHA into the hole.
[0027] In another embodiment, the liner drilling assembly 100 may be retrieved to a safe location in the wellbore. For example, the liner drilling assembly may be retrieved back to surface. The liner string 120 may then be hung on the rig floor slips. Then, the BHA may be replaced and the liner drilling assembly may be tripped back into the hole.
[0028] In another example, the liner drilling assembly 100 may be retrieved to a position inside the previously installed casing 10 . In one embodiment, the liner drilling tool 100 may be suspended just below a blow out preventer (“BOP”). FIG. 2 shows an embodiment of a BOP 200 for suspending a liner drilling assembly in a wellbore. As shown, a liner retaining BOP ram 210 is coupled to a BOP stack having a pipe ram BOP 215 and an annular BOP 220 . It must be noted that the liner retaining BOP ram 210 may be integrated with or an attachment to the BOP stack. The liner top assembly 115 may include a profile 230 for engaging with the ram of the liner retaining BOP 210 . The ram may be hydraulic actuated to move radially into engagement with the profile 230 . Alternately, the liner top 115 may include a hanging shoulder adapted to rest on liner retaining BOP ram. The liner top 115 may be retained using a combination of a profile and/or hanging shoulder. The pipe ram BOP 215 and the annular BOP 220 are then used to close around drill pipe 110 during well control situations. In this respect, the hydraulic forces from the BOP ram are used to park the liner 120 in the wellbore. In one embodiment, one or more sensors may be used to position the liner top assembly 115 relative to the liner retaining BOP ram 210 . An exemplary sensor includes a magnet. The magnet may be positioned on the liner hanger and a sensor may be mounted on the BOP ram 210 to determine the position of the magnet and thereby, the location of the liner hanger (e.g., the profile 230 ). It is contemplated that other suitable sensors such as RFID sensors known to a person of ordinary skill in the art may be used.
[0029] In operation, the liner drilling assembly 100 is retrieved sufficiently so that the liner top 115 is adjacent the liner retaining BOP 210 . Then, hydraulic forces are applied to radially move the ram into engagement with the liner top, either by way of the profile, the hanging shoulder, or both. Once parked, the liner drilling tool 116 and the drilling latch 140 are released and the BHA is pulled out of the hole. After the BHA is repaired, the BHA is run-in and the liner drilling tool 116 and the drilling latch 140 are actuated to re-engage the liner 120 . Thereafter, the ram is retracted and the liner drilling assembly 100 is released for further drilling. During operation, while the liner drilling assembly is parked in the wellhead 250 , the well may experience an undesired increase in pressure. To prevent a blowout, the other BOP devices (such as pipe rams, annular preventer, and/or shear rams) may be actuated to mitigate wellbore influxes.
[0030] In another embodiment, the liner retaining BOP 210 may be used to facilitate running in the liner drilling assembly. For example, the liner may be initially run-in to the liner retaining BOP 210 . Thereafter, the BHA is coupled to the drilling latch, liner running tool, and the drill pipe, and is tripped into the liner. Then, the liner running tool and the drilling latch are activated to engage the liner, thereby forming the liner drilling assembly. The retaining BOP 210 is deactivated to release the liner drilling assembly to commence drilling.
[0031] In another embodiment, the liner top assembly 115 may be adapted to engage a wall of the previously installed casing 10 . The casing may include a liner receiving profile formed on an interior surface of the casing. The liner receiving profile may be adapted to engage the liner hanger of the liner drilling apparatus. In operation, the liner drilling assembly is retrieved sufficiently so that the liner top is adjacent the liner receiving profile. Then, the liner hanger is actuated to engage the profile. Once parked, the liner drilling tool and the drilling latch are released, and the BHA is pulled out of the hole. After the BHA is repaired, the BHA is run-in and the liner drilling tool and the drilling latch are actuated to re-engage the liner. Thereafter, the liner hanger is retracted and the liner drilling apparatus is released for further drilling. It is contemplated that the liner receiving profile may be formed in the previously set casing 10 or the wellhead 250 . Further, it is contemplated that the drilling liner assembly may be retrieved to any suitable portion of the wellbore and suspended therein. It is further contemplated that the liner hanger may engage any portion of the casing, with or without using a liner receiving profile. In this respect, the releasable and re-settable liner hanger may be used to park/hang the liner in the previously set casing 10 . The drilling liner 120 may be left in the open hole or pulled back into the set casing to prevent getting the liner stuck during the BHA replacement trip. The releasable and re-settable liner may be actuated multiple times for potentially multiple BHA trips into and out of the hole.
[0032] In another embodiment, the releasable and re-settable liner hanger may be used to facilitate run-in of the liner drilling assembly. For example, the liner equipped with a liner hanger is initially run-in to the casing. Thereafter, the liner hanger is activated to engage the casing and suspend the liner. Then, the BHA is coupled to the drilling latch, liner running tool, and the drill pipe, and is tripped into the liner. Then, the liner running tool and the drilling latch are activated to engage the liner, thereby forming the liner drilling assembly. The liner hanger is deactivated to release the liner drilling assembly to commence drilling.
[0033] In another embodiment, the liner drilling assembly may be run without using the inner string. To retrieve the BHA in the event of failure, the liner is first suspend in the wellbore using any of the above described methods of suspension. Then, a work string is lowered into the wellbore to retrieve the BHA. Exemplary work string includes drill pipe, wireline, coiled tubing, Corod (i.e., continuous rod), and any suitable retrieval mechanism known to a person of ordinary skill in the art. In one embodiment, wireline is used to retrieve the BHA. After the BHA is replaced or repaired, the BHA is lowered back into the liner and the drilling latch is activated. Then, the drill pipe may be lowered and the liner drilling tool is activated to engage an upper portion of the liner. Thereafter, the liner is released from suspension to continue the drilling operation.
[0034] FIG. 3 shows, another embodiment of the liner drilling assembly 300 . The liner drilling assembly 300 is connected to a drill pipe 310 using a running tool 320 . The running tool 320 may releasably attach the liner 305 to the drill pipe 310 and transmit axial and torsional forces. The liner drilling assembly 300 also includes a liner hanger 325 for hanging the liner 305 in a casing 301 . An inner string 330 connects the running tool 320 to the casing latch 335 . In one embodiment, the inner string 330 may include a pressure and volume balanced extension joint with swivel 337 . The inner string 330 may stab into the latch 335 using a spear 340 . The latch 335 is adapted to releasably attach to the latch in collar 345 of the liner 305 . Any suitable latch known to a person of ordinary skill in the art may be used. One or more non-rotating or rotating centralizers 350 may be used to centralize the liner 305 relative to the casing 301 or the drilled hole. The lower end of the liner 305 may include a casing shoe 355 . As shown, the BHA 360 extends below the liner 305 . The BHA 360 may include a motor, MWD/LWD, and rotary steerable systems. One or more under-reamer 365 and/or pilot bit 370 may be used to form the wellbore. It must be noted that the BHA 360 may include other components, in the to or in place of above listed items, such as other geophysical measurement sensors, stabilizers such as eccentric or adjustable stabilizers, steerable systems such as bent motor housing, other drill bits such as expandable bit or bits having nozzles or jetting orifices for directional drilling, or any other suitable component as is known to a person of ordinary skill in the art. Further, the components of the BHA may be arranged in any suitable order as is known to a person of ordinary skill in the art.
[0035] In operation, a sufficient length of liner 305 with the casing shoe 355 and latch in collar 345 is run so that the casing latch 335 and the BHA 360 may be installed in the liner 305 . Then, the remainder of the liner 305 is run in the hole, as illustrated in FIG. 4 .
[0036] After running the liner 305 , the liner hanger 325 is installed on top of the liner 305 , as illustrated in FIG. 5 . The inner string 330 is run inside the liner 305 with the stab in seal assembly 340 on bottom and the pressure volume balanced slip joint 337 below the running tool 320 . The running tool 320 is installed on the end of the inner string 330 and the combined tool 320 /string 330 are installed in the liner hanger 325 . The drilling assembly is now actuated to proceed to drill to the desired depth. Axial and torsional forces may be transmitted from the drill pipe 310 to the liner 305 through the running tool 320 and the latch 345 . In another embodiment, the inner string 330 and the running tool 320 may be connected at the surface and run into the wellbore together for connection with the liner hanger 325 . In yet another embodiment, the liner hanger 325 , inner string 330 , and the running tool 320 may be run in as an assembled apparatus for installation on the liner 305 .
[0037] After desired depth is reached, the liner hanger 325 is set. In FIG. 6 , it can be seen that the slips of the liner hanger 325 have been radially extended to engage the previously set casing. The setting of the liner hanger also triggers the release of the running tool 320 from the liner 305 . After the latch 335 is also released the running tool 320 is pulled along with the inner string 330 , casing latch 335 , and BHA 360 out of the hole, as illustrated in FIG. 6 .
[0038] In one embodiment, the cementing operation may be performed by running a first (e.g., 16″) packer such as a squeeze packer 381 into the liner 305 . The packer 381 may include slips 383 to engage the interior of the liner 305 . Thereafter, cement is pumped through the packer 381 to squeeze the bottom of the liner 305 , as shown in FIG. 7 . In another embodiment, a second (e.g., 20″) squeeze packer may be installed in the liner 305 and a cement squeeze is performed at the top of the liner 305 . The cement from this second cement squeeze is directed to the annulus between the top of the liner 305 and the liner hanger 325 , and into the formation just below the bottom of the previously run casing. In one embodiment, pressure is applied through the drill string to the top of the liner below the packer set in the ID of the previously run casing located above the liner top. This applied pressure is typically referred to as break down pressure. After establishing the break down pressure, cement is pumped in from surface, circulated down, then squeezed into the annulus between the casing hanger and the previously run casing until a suitable pressure is achieve, which is typically higher than pump in pressure (squeeze pressure). In this respect, the higher pressure provides an indication that a cement barrier has been established at the top of the liner.
[0039] In another embodiment, the cementing operation may be performed using subsurface release plugs 375 , 376 , as shown in FIG. 8 . Initially, a wireline set packer 385 having a check valve 387 is run in and is set near the bottom of the liner 305 . Then, a modified running tool 390 containing subsurface release (“SSR”) type cementing plugs 375 , 376 is positioned on top of the liner 305 . A SSR type cementing job is the performed as is known in the art. After cementing, the packing element is set at the top of the liner hanger 325 and the modified running tool 390 is pulled out of the hole.
[0040] FIG. 9 shows another embodiment of a drilling with liner assembly of the present invention. As shown, the drilling liner assembly 900 extends below a previously installed casing 10 . The drilling liner assembly 900 is run in on drill pipe 910 . A liner drilling tool 916 is used to connect the drill pipe 910 to the liner 920 . The liner drilling tool 916 may be a component of the liner top assembly 915 , which may also include a liner hanger 917 and a polished bore receptacle (“PBR”). In one embodiment, the liner drilling tool functions as a running tool for connecting the drill pipe 910 to the liner 920 . The running tool may include a latch and/or gripping members that may releasably attach and detach from the liner 920 . The running/drilling tool is adapted to transmit axial and torsional forces from the drill pipe 910 to the liner 920 . The running tool may be released from the liner 920 so that the BHA may be retrieved. Preferably, the running tool has torque capability that equals or exceeds the drill pipe capability and is adapted to endure typical bore hole drilling dynamics. Exemplary running tools are disclosed in U.S. Pat. Nos. 5,613,567, 5,531,273, and 6,032,734, which patents are incorporated herein by reference in their entirety. The liner top equipment (liner hanger and PBR) may also include large radial clearance for cuttings bypass and reduced ECD and setting of liner hanger does not reduce the annular clearance area significantly. In one embodiment, setting of the liner hanger and release of drilling tool may be independent of the differential pressure between the inside of the tool and the outside of the liner to prevent premature activation. In another embodiment, the liner top assembly is not equipped with a packer. In yet another embodiment, the liner top assembly utilizes an expandable liner hanger and/or expandable packers.
[0041] An inner string 930 extends from the liner running/drilling tool 916 to a drilling latch 940 below. The inner string 930 may be used to convey fluid from the drill pipe 910 and/or to retrieve the BHA. Also, it should be noted that fluid may be conveyed outside of the inner string, inside of the inner string, or the flow split between both. In one embodiment, the fluid returning to the surface may flow through the annular area between the wellbore and the outer diameter of the liner and/or the annular area between the inner diameter of the liner and the outer diameter of the inner string. The drilling latch 940 is adapted to releasably connect to the liner 920 . An exemplary drilling latch is disclosed in U.S. Patent Application Publication No. 2004-0216892, filed on Mar. 5, 2004 by Giroux et al. having Ser. No. 10/795,214, entitled Drilling With Casing Latch, which application is herein incorporated by reference in its entirety. The drilling latch 940 is adapted to transfer axial and torsional forces from the liner 920 to the bottom hole assembly (“BHA”). The drilling latch 940 may be hydraulically, mechanically, or remotely actuated. Suitable actuating mechanism includes mud pulse technology, wire line, and fiber optics.
[0042] As shown in FIG. 9 , the bottom hole assembly includes one or more stabilizers 955 , a motor 960 , an under-reamer 965 , MWD/LWD 970 , rotary steerable systems 975 , and a drill bit 980 . It must be noted that the BHA may include other components, in addition to or in place of the listed items, such as other geophysical measurement sensors, stabilizers such as eccentric or adjustable stabilizers, steerable systems such as bent motor housing, other drill bits such as expandable bit or bits having nozzles or jetting orifices for directional drilling, or any other suitable component as is known to a person of ordinary skill in the art. Further, the components of the BHA may be arranged in any suitable order as is known to a person of ordinary skill in the art. For example, the under-reamer may be place below the motor and MWD/LWD tool.
[0043] While the foregoing is directed to 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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In one embodiment, a method of forming a wellbore includes running a liner drilling assembly into the wellbore, the liner drilling assembly having a liner, a conveying member, one or more connection members, and a drilling member. The method includes temporarily suspending the liner at a location below the rig floor; releasing the conveying member and the drilling member from the liner; re-connecting the conveying member to the liner; releasing the liner from its location of temporary suspension; and advancing the liner drilling assembly.
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The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a division of application Ser. No. 07/204,316 filed June 9, 1988 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention generally relates to coating materials and to a process for preparing antifouling coating compositions incorporating metal oxides, particularly cuprous oxide in water-based paints, which are suitable for use in protecting underwater surfaces from hard fouling and slime build up.
2. Description of the Prior Art
In the prior art metal oxides have been used as toxicant pigments dispersed in solvent-based film forming vehicles. The most widely used form of such prior art is the red vinyl cuprous oxide antifouling paint, known as paint Formula No. 121, which consists of as much as 70-72% by weight of cuprous oxide with 86% copper content. The black version of this paint, known as paint Formula No. 129, consists of 58% cuprous oxide with 13% black iron oxide representing 68.5% copper in the pigmentation. Plastic shipbottom paints may contain a combination of 40% cuprous oxide with 11% zinc oxide and 3.8% magnesium silicate extender. For underwater use on rubber surfaces, a polyisobutylene polymer and 52.8% by weight of cuprous oxide or mercury compounds including mercuric oxide as toxicants are employed in antifouling paint coatings. Other heavy metal toxicant agents, including tin, lead, and arsenic compounds, and other organic toxicants, including fungicides and biocides, are also employed in antifouling paints that use cuprous oxide as the primary toxicant.
All of the above formulations are organic solvent-based paints and therefore release, on application, undesirable solvent vapors into the atmosphere. They also release afterwards, on water immersion, retained organic solvent matter into the water of the environment. While the normal mechanism of toxicant release involves a gradual loss of the soluble vehicle components by lixiviation, subsequent loss of the cuprous oxide is experienced by chemical reaction with seawater forming copper complexes of varying solubilities, depending upon the local concentration of hydrogen ion. Furthermore, the cuprous oxide can react during initial dispersion with the film forming polymeric resinous components of the vehicle, in particular the abietic acid of the rosin, so as to form copper compounds, such as copper resinate, which are also soluble and which may result in considerable amounts of toxic underwater releases.
The process of this invention is different from the present emulsification treatment used to incorporate inorganic metal oxides in some water-based latex paint formulations. Metal oxides have been emulsified for dispersion in water-based paints by reacting them with lecithin, a naturally occuring compound that consists of a mixture of diglyceride esters of certain fatty acids linked to the choline ester of phosphoric acid. These emulsified metal oxides, however, do not effectively release the metal toxicant when incorporated in a water-based latex formulation. The fluid lecithins are soluble in organic solvents only, and do not represent the products of polymerization treatment. Thus, even when the so reacted metal oxides are recovered and are again dispersed in water-based paints, they do not release toxicant effects themselves and are useful in antifouling paints only when organometal toxicants have been added.
Water-based antifouling paint formulations based on latex resins have not been used commercially for fouling protection in marine immersion applications. The previous water-based antifoulant paint formulations utilize water-based polymer latexes or water-dispersed alkyd resins with inorganic pigments which are not, or only slightly, reactive with such water-dispersed binder vehicles. They therefore, did not interfere with the stability and application of the water-based paints but, on the other hand, they did not contribute to the antifouling protection. This aspect was left to be accomplished by the incorporated organometal toxicant. Heavy metal inorganic antifoulants such as cuprous oxide have not previously been used due to the reaction with the vehicle. The reaction product of the metal oxides with the latex resin forms clumpy or grainy reaction products which settle during storage and are difficult to redisperse thus deteriorating paint application and performance.
Although the organometal toxicants are compatible with latex based antifouling formulations, most coating systems of this type contain various water soluble pigments, fillers and binders so that the organometals diffuse into the immersion water at high initial rates which decrease logarithmically with time. Various polymeric binder compounds have been developed to control the release rates of these organometal toxicants as exemplified by, for example, U.S. Pat. Nos. 3,016,369; 3,382,264; 3,930,971; 3,979,354; 4,064,338; 4,075,319; 4,174,339; 4,389,460; and 4,480,056.
SUMMARY OF THE INVENTION
Under these circumstances, it is highly desirable to develop methods to use metal oxides in antifouling paints under conditions where the rate of the toxic metal release can be held at lower levels and where the continuing release of retained organic solvents can be avoided. This is achieved by the present invention by modification of the metal oxide in a manner which allows its use in water-based antifouling paints.
Although metal oxides are widely used as toxic pigments in solvent-based antifouling paints, the present invention establishes that it is possible to make metal oxides applicable to such use in water-based antifouling paints without the need to also include additional organometal toxicants. The present invention is a method for modifying the surface of the metal oxide pigment particles with a water-dispersed polymeric resinous material, the product of which can be subsequently used in water-based paint formulations for the protection of surfaces exposed to a marine environment. By prior surface treatment of the metal oxide pigment particle with a water-dispersed polymeric resin, a modified metal pigment may be recovered and incorporated into new water-based antifoulant coating formulations.
The process of the present invention is a method for pretreating the surface of metal oxide pigment particles with water-dispersed polymeric resinous materials by intensively milling or mixing the constituents, then separating by filtration the reaction products, whereby water-dispersable polymeric resin modified metal oxide pigment particles and a metal oxide modified resin filtrate are obtained. The water-dispersable polymeric resin modified metal oxide particles represent a water-dispersable toxicant pigment for use in water-based antifouling paint formulations. When subsequently incorporated in antifouling paint formulations, the water-dispersable polymeric resin modified metal oxide pigment provides a continuous release of metal toxicant from the surface of the paint, thus providing continuing protection against undesirable growth of plant and animal life.
The present invention provides a process for formulating a low leaching marine antifouling coating composition of sufficient toxicity for preventing the growth of fouling organisms on marine structures, which comprises intensively mixing at least one metal oxide pigment solid with a water based latex material in the presence of water, separating the reaction products obtained from said mixing step consisting of latex modified metal oxide powder and metal oxide modified latex filtrate, in some cases adding an additional unmodified metal oxide pigment to the latex modified metal oxide powder, and dispersing the latex modified metal oxide powder in at least one water dispersed resinous binder vehicle in the presence of a solvent or in the presence of a solvent and antifoaming agent recovering a complex marine antifouling coating composition of sufficient toxicity to prevent the growth of fouling organisms on marine structures.
The process of the present invention transforms the metal oxide into complex matter between inorganic metal oxide and organic water-dispersable polymeric resinous material which renders the so modified metal oxide capable of being incorporated, alone or with other pigments, into new water-based antifouling coating compositions. The present invention modifies the metal oxides, in particular cuprous oxide with polymeric resinous materials, so as to yield the polymeric results of an emulsion polymerization of synthetic elastomeric materials. They therefore represent polymeric water-dispersables which are free of any glycerin esters or their solvent dispersions which have been used in the past lecithin treatment of metal oxides.
The rate of release of the metal toxicant from the new antifoulant paint formulations is reduced and the emission levels are lower when compared to conventional cuprous oxide paints. The present invention also makes it possible to prepare antifouling compositions with water as the main, or only if so desired, solvent while concurrently increasing the resistance of the applied compositions against the softening effect of engine oil, lubricating oils, and other non-drying oils.
Accordingly, an object of this invention is to establish a process and application for use of metal oxides as toxicant pigments in coating compositions without resulting, on storage, in development of solid coagulations and hard sedimentations which would be difficult to redisperse or apply smoothly in a desirable coating form.
Another object of the present invention is to limit the rate of toxic metal oxide released from the applied coating. The purpose of these compositions, on immersion in water, is to limit the release of toxic matter into the water and into the marine environment from sources such as operating ships and maritime installations which are coated with such compositions.
A further object of the present invention is to provide a water-based antifoulant paint which is effective in protecting submerged surfaces against the growth of marine organisms without having to incorporate therein an organometal toxicant.
Yet another object of the present invention is to increase the oil resistance of the applied coatings due to the increased resistance of water-based polymeric coatings against the effects of surface contamination by non-drying oils, such as motor oils, or pastes containing such non-drying oils.
Other objects and many of the attendant advantages of the present invention will be appreciated as the same become better understood by reference to the following examples and claims.
DETAILED DESCRIPTION OF THE INVENTION
The following specific examples are intended to illustrate the invention but not to limit it in any way:
EXAMPLE 1
1 part or 50 grams by weight of cuprous oxide (Type AA Glidden Durkee, SCM Corp.) are mixed with 1 part or 50 grams by weight of water and 2 parts or 100 grams by weight of polyacrylic latex (Rhoplex AC-235 -46% solids, Rohm & Hass Corp.) and the composition is intensively mixed or milled at room temperature for several hours. The mixing operation may be accomplished by several techniques including either ball or sand mill grinding, although ball milling is the preferred method since it has proven effective in providing the desired surface modification and thus will hereinafter be referred to. The latex-modified cuprous oxide solid is then isolated on a filter, with the cuprous oxide-modified latex representing the filtrate. The latex-modified solid pigment on the filter is further rinsed with water to remove adherent latex matter.
The fact that a modification of the cuprous oxide solid takes place on ballmilling with such a latex is established by comparison. After drying, the surface-modified pigment as well as a unmodified pigment are dispersed in mineral oil and the infrared spectra of these dispersions taken. The infrared analysis with a P-E Fourier Transform Infrared Spectrophotometer exhibits relative changes occurring in the spectra due to the presence of this latex-modified metal oxide reaction product.
The filtrate represents a copper modified latex whereby the copper is bound to the latex group via an oxygen grouping resulting from the use of the cuprous oxide as a modifier of the latex. This combination of inorganic and organic groupings is different from the formation of the conventional organometal toxicants used in antifouling paints, where several organic radicals are bound directly to the metal.
To establish that the copper actually enters the latex, 1 part or 50 grams by weight of cuprous oxide is ballmilled with 1 part or 50 grams by weight of water and 2 parts or 100 grams by weight of acrylic latex for 16 hours. The modified pigment is filtered off the filtrate. This filtrate then contains, according to Atomic Absorption Analysis, 16.500 micrograms of copper. This copper is present in the form of a complex over an oxygen grouping to the acrylic latex group. Therefore, this metal oxide-modified latex filtrate, is itself considered to have antifoulant properties.
The invention modifies the metal oxides, in particular cuprous oxide with a water dispersion of synthetic rubber latexes which represent the polymeric results of an emulsion polymerization of synthetic elastomeric materials. They therefore represent polymeric water-dispersions which are new and useful reaction products. The surface-modified cuprous oxide solid, in particular releases, when subsequently dispersed in water-based paints, a new complex release which has toxic effects itself and does not require the addition of an organometal toxicant, even though such material might be added when desired (see Example 6).
EXAMPLE 2
The preparation of the surface modifications is not limited to the acrylic latexes used in Example 1. Corresponding modifications are also made with the polyvinyl latexes as in this example, and other water-dispersed polymeric resinous materials such as other water-based polymer latexes and water-dispersed resinous materials such as water-dispersed alkyd resins where an interaction with cuprous oxide can take place. For instance, 2 parts or 150 grams by weight of cuprous oxide (Type AA Glidden Durkee, SCM Corp.) are mixed with 1 part or 75 grams by weight of water and 1 part or 75 grams by weight of polyvinyl acetate latex (Polyco 117 SS, Borden Corp.) and are ball milled at room temperature for several hours. The reaction between the cuprous oxide and the latex forms a gel state. Under the addition of more water to the mill product and through mixing of the components, the gel state is overcome. The surface-modified solid pigment is then separated by filtration.
The latex-modified cuprous oxide pigment has a tendency to agglomerate upon drying due to some residual adherent latex that is not involved in the formation of either the modified latex filtrate or the modified cuprous oxide. The remove the residual adherent latex from the latex-modified cuprous oxide pigment, the pigment is milled again with water, whereby the residual latex becomes a part of the mill water. Upon filtration, the residual latex remains in the filtrate and the modified pigment is collected and dried. The latex-modified cuprous oxide pigment particles can then be readily reduced to the desired size of a fine powder by renewed ballmilling.
To determine to what extent the copper grouping is present as a complex, 3 parts or 150 grams by weight of cuprous oxide are ballmilled with 2 parts or 100 grams by weight of water and 1 part or 50 grams of polyvinyl acetate latex; and, after filtering, the filtrate was analyzed using the Eberbach Electro-analyzer. The electric current of this instrument carries free metal ions to the platinum cathode, while the metal-organic complexed matter is carried to the anode. It is found that 57.4 percent of the composition is deposited at the cathode and 42.6 percent is deposited at the anode. The deposit at the anode indicates that this composition contains a representative complex between the metallic copper and the organic ligand.
EXAMPLE 3
The cuprous oxide is first surface-treated in accordance with Examples 1 or 2 and such already modified cuprous oxide pigment is then introduced into a film forming composition by techniques including the use of high speed dispersion and dispersing agents. Acceptable binder vehicles include water-dispersed polymeric resinous materials such as water-based latexes selected from the group consisting of polyvinyl acetate latex, acrylic latex, polyacrylic latex, urethane latex, and polyurethane latex; and water-dispersed resinous materials selected from the group consisting of alkyd resins, and others; and other water-based polymeric reactive materials. Therefore, paint compositions with latex binder vehicles can be further modified by also introducing a water-dispersed alkyd resin in water.
A formulation in accordance with this example is made as shown below:
______________________________________Cuprous oxide, pretreated as in Ex. 2 84.0 grams by weightPolyvinyl acetate latex 18.0 grams by weightWater-dispersed alkyd resin 36.0 grams by weight(Aroplaz 585, Spencer Kellogg, Textron Inc.)Water 20.0 grams by weightAntifoaming agent (Nopco NXZ) 4.5 grams by weightA dispersing agent may be introduced also.______________________________________
The surface-modified cuprous oxide according to the present invention can thus be used in any application, including organic solvent based paints, where the unmodified cuprous oxide had been used in antifouling paints and other coating applications. Moreover, the modified cuprous oxide can be introduced effectively into water based coating materials without interfering with the storage stability of such coating materials. The complex formation between the water-insoluble cuprous oxide and the water-based latex or other water based paint components, such as water-based alkyd resins, in applied coatings results in a gradual release of copper containing complexes into the immersion water. It therefore provides, on the surface to which it is applied, a progressing and continuous toxicant protection against marine growth.
EXAMPLE 4
Such antifoulant compositions can also be prepared using cuprous oxide in its initial form and producing the modification within the water based coating composition. Specifically, 1 part or 50 grams of cuprous oxide (Type AA Glidden Durkee, SCM Corp.) by weight is ball milled with 1 part or 50 grams by weight of water and 2 parts or 100 grams by weight of acrylic latex (Rhoplex AC-235-46% solids, Rohm & Hass Corp.) at room temperature for several hours. The ball milled product is then used as a surface coating without further treatment.
It is a result of the use of water-based polymeric vehicles in the preparation of the cuprous oxide/latex reaction products that the obtained applied coating is considerably more resistant to non-drying oils than the the conventional cuprous oxide paints. For instance, two coats of conventional solvent-based cuprous oxide antifouling paint are applied to steel panels, in some cases over an applied wash-primer, and the air dried panels were coated with an oil-paste consisting of 97 parts by weight non-drying oil such as paraffin oil-based motor oil (Gulflube XHD, Gulf Oil Corp.) and 10 parts by weight silica pigment (Aerosil 380 of Degussa, Inc.). The panels were exposed at 49° C. (120° F.) for one hour and were allowed to dry at room temperature. After removing the oil-paste layer, one panel was exposed in hot (80° C.(176° F.) water, whereafter the vinyl red solvent-based antifouling paint lifted off from the edges. The water-based paints with the modified cuprous oxide formulated in accordance with the present invention showed no softening effect from the same treatment.
EXAMPLE 5
Such film forming compositions can be prepared using cuprous oxide as the only toxic pigment or using cuprous oxide in combination with other metal oxide pigments. Other metal oxides suitable for use with the surface-modified cuprous oxide are selected from the group consisting of zinc oxide, lead oxide, tin oxide, iron oxide (black or red), magnesium oxide, cadmium oxide, arsenic oxide, and mercuric oxide, and other heavy metal oxides, in their initial form or in their so modified form. In such combined applications, the coated surface during immersion releases copper complexes in addition to complex releases from the other metal components.
A formulation in a water-based paint in accordance with this example is made as shown below:
______________________________________Cuprous oxide, pretreated as in Ex. 2 84.0 grams by weightZinc oxide, pretreated with 60.0 grams by weightpolyvinyl acetate latexPolyurethane latex 88.0 grams by weight(Witcobond W234 of Whitco Chemical Company)Water 20.0 grams by weightAntifoaming agent (Nopco NXZ) 4.50 grams by weightA dispersing agent may be introduced also.______________________________________
EXAMPLE 6
The paint compositions of Examples 3, 4, and 5 are further modified by introducing, in addition to the latex-modified metal oxide pigment, a small amount of organometal toxicant selected from the group consisting of triphenyltin acetate (TPTA), tributyltin oxide (TBTO is a registered trademark of M&T Chemicals, Inc.), tributyltin acetate (TBTA), tributyltin sulfide (TBTS), tributyltin fluoride (TBTF), triphenyltin fluoride (TPTF), triphenyltin hydroxide (TBTH), triphenyltin chloride (TPTC), triphenyllead acetate (TPLA), and phenyl mercuric acetate, and combinations of these such as TBTF/TPTF, and others. Such a paint composition is prepared in three steps, as follows:
______________________________________Step 1Triphenyltin acetate (TPTA) 2.25 grams by weightAcetone 1.00 grams by weightWater 5.00 grams by weightWater-dispersed alkyd resin 54.50 grams by weight(Aroplaz 585, Spencer Kellogg, Textron Inc.)Step 2Cuprous oxide, pretreated as in Ex. 2 84.0 grams by weightZinc oxide, pretreated with 60.0 grams by weightpolyvinyl acetate latexPolyurethane latex 88.0 grams by weight(Witcobond W234 of Whitco Chemical Company)Water 70.0 grams by weightAntifoaming agent (Nopco NXZ) 4.5 grams by weightA dispersing agent may be introduced also.Step 3The material of Step 1 is then ball milled with that of Step 2 forat least one hour.______________________________________
EXAMPLE 7
When paint containing an already latex-pretreated metal oxide pigment is used with additional cuprous oxide within the same water-based coat forming vehicle, cuprous oxide in its initial form can be introduced as the additional pigment and will then participate in the coating formation and in the resulting toxicant release from the applied coating. This is established by preparing, applying and immersing a paint which has the same composition as the antifoulant paint of Example 5, but using the cuprous oxide in a not-modified form jointly with the latex-modified zinc oxide. In the same manner, the paint formulation of Example 6 can be prepared using the latex-modified zinc oxide jointly with unmodified cuprous oxide.
In order to produce antifouling effects on the coated surfaces it is necessary that the coated surfaces release, under water immersion, the copper containing copper complex. This is verified by immersing 3"×6" steel panels coated with one of the paint compositions of Example 6 or this Example in distilled water for 20 days at room temperature. The immersion water containing the released complex matter is then used to immerse either automotive steel (R-36, Q-Panel) or a high grade galvanized steel alloy (such as GALFAN of International Lead Zinc Research Organization, Inc.) whereby an immersion plating effect takes place in both cases. These deposits are identified as changes in the reflectance of the metal surfaces, after immersion into the release-containing waters, using a Photovolt Reflection Meter with blue, green, and amber tristimule filters.
The reflectance of the immersed metals are as follows:
______________________________________ REFLECTANCE READING BLUE GREEN AMBER______________________________________Steel Surface:Before Immersion 21 24 21After Immersion 12 12 12.5Galvanized Steel:Before Immersion 40 28 41After Immersion 19.5 15 21______________________________________
The quantitative extent to which the copper release compares with concurrent zinc releases from the paints using cuprous oxide jointly with latex-modified zinc oxide is also of importance. The paint of Example 5, using latex as the only film former and using both modified cuprous oxide and modified zinc oxide, releases 1.6 ppm copper and 29.8 ppm zinc after 163 days of immersion. The corresponding paint of this Example, containing the modified zinc oxide with not-modified cuprous oxide, releases 1.7 ppm copper and 28.8 ppm zinc after 163 days of immersion.
The paints with latex and alkyd resin in the binder vehicle show an even greater difference between the copper and the zinc releases. The paint of Example 6 with pretreated zinc oxide and pretreated cuprous oxide releases, after 234 days of immersion, 0.9 ppm copper and 37.1 ppm zinc. The corresponding paint of this Example, containing pretreated zinc oxide and unmodified cuprous oxide in the formulation, releases only 0.4 ppm copper and 47.4 ppm zinc after 234 days of immersion.
Based upon the above data, it is evident that the zinc oxide complex will migrate from a combined pigment composition at a much faster rate than the copper complex, thereby restricting the copper contamination of the environment. Since zinc oxide is itself an anti-mold acting pigment, the presence of such zinc containing released matter contributes, together with the released copper complexes, to the preservation of the immersed coatings in fouling waters while simultaneously reducing the toxic copper-carrying emission level.
EXAMPLE 8
The fact that this release of copper carrying complex is actually considerably lower and, for environmental protection, more desirable than is the case with the prior cuprous oxide paints is demonstrated by comparing the amount of copper released into immersion waters from the prior solvent-based paints with the new water-based coatings of the present invention.
A conventional vinyl cuprous oxide antifouling paint (such as Formula No. 7628 of Hempel Company) is applied to 3"×6" steel panels and after 70 days of immersion in 500 ml of water at room temperature has an accumulated concentration of copper in the amounts of 6.5 and 7.0 ppm, according to analytical measurements with the Perkin-Elmer Atomic Absorption Spectrophotometer Model 3030. This corresponds to a normalized copper emission level equal to 0.0054 ppm/sq.in./day. The new latex modified paint of Example 5 has an accumulated concentration of 1.6 ppm copper after 163 days of immersion in 500 ml of water, according to four separate analytical measurement tests with the Perkin-Elmer Atomic Absorption Spectrophotometer Model 3030. This corresponds to a normalized copper emission level equal to 0.0005 ppm/sq.in./day. When the binder vehicle which is used produces a denser film by combining the latex with a water-dispersed alkyd resin within the new paint, as in accordance with the formulation of Example 6, the accumulated concentration after 234 days of immersion in 500 ml of water is only 0.9 ppm copper which corresponds to a normalized copper emission equal to 0.0002 ppm/sq.in./day.
Any of the new antifoulant paint compositions of the preceding examples may be applied to selected surfaces, such as fiber-glass board, metal surfaces, and others, directly or after applying primer coatings to such surfaces. Compatible primers in accordance with the present invention are the wash primers or a combination of such wash primers followed by shipboard vinyl red lead primer, and others. Furthermore, the new antifouling paint formulations may receive finish coats with paints such as the vinyl alkyd enamels which have been found suitable as a so-called top coat. In all of these applications the immersed coated surface will release copper-containing water soluble material, which can be identified by various techniques such as were used to analyze the releases from the prior solvent-based cuprous oxide antifouling paints.
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 low leaching nonpolluting marine antifouling coating formulation and a cess for preparing the same which comprises surface pretreatment of the metal oxide pigment particles with a water-dispersed organic polymeric resinous material, such as by intensively mixing or milling the metal oxide pigment and the resin, in order to recover a water-dispersable polymeric resin modified metal oxide pigment for subsequent incorporation into new water-based coating formulations.
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BACKGROUND
The present invention relates to an instrument stand and more particularly, to a collapsible and portable instrument stand that is capable of supporting an instrument in a suspended fashion.
Portable instrument stands for supporting an elongate musical instrument by its base in a generally upright orientation are well known in the art. Where the instrument is a guitar, bass or the like, the stand supports the elongate instrument in an upright orientation with its longitudinal axis maintained generally vertically. A typical conventional stand comprises a multi-leg assembly including at least first and second vertically extending rigid legs disposed at a relative angle, with supports projecting outwardly from each of the legs for cooperatively supporting the base of the elongated instrument thereon. The multi-leg assembly may be tripod-like, in which case there is also a third vertically extending rigid leg. The tripod-like multi-leg assembly may be movable between a collapsed storage configuration, wherein all the legs extend generally parallel to one another, and a for-use configuration wherein all the legs are deployed at an angle to one another so as to provide a stable support for an instrument. Alternatively, the multi-leg assembly may include only the first and second legs disposed at a relative angle, with each of the legs having disposed at the free end thereof, opposite the junction of the legs, a stabilizing foot or base member extending transverse to a plane defined by both of the legs, thereby providing a stable base for the stand.
An example of a conventional collapsible musical instrument stand is set out in U.S. Pat. No. 3,958,786 to Mann. The instrument stand disclosed by Mann is a portable variety that supports a string instrument by its base while the instrument's neck rests on an extendable support. The stand is partially collapsible for storage and transport purposes. However, even when collapsed, the stand described by Mann generally remains bulky and cannot conveniently be transported in an instrument case.
A limitation of these prior art stands is that they support an instrument primarily by the instrument's base end, thereby potentially imparting undue mechanical stress. It will be further appreciated by those skilled in the art that horizontal instrument stands, such as those for supporting keyboards, are also unsuitable for supporting finer instruments. When a conventional horizontal stand is used to support a guitar, or other stringed instrument, the instrument's longitudinal axis may be sharply tilted laterally to one side or the other whereby the instrument rests in large part on its neck, thereby imparting undue stress.
Because conventional portable instrument stands support a stringed instrument primarily by its base and only secondarily by its neck in a leaning arrangement, such stands may not be entirely suitable for supporting more delicate stringed instruments, such as violins and violas. Such instruments are more properly supported in a suspended arrangement to avoid imparting undue stress on a base, or body portion, thereof. This may be done by hanging the stringed instrument from its neck in the case of a guitar (e.g., by use of dual hooks which clinch the flair at the base of the tuning peg board), or from its scroll in the case of a violin or viola. Indeed, in a fixed storage arrangement, such as an instrument cabinet, string instruments are typically supported by hanging. As those skilled in the art will appreciate, the latter is the recommended storage technique when a stringed instrument is not being transported. However, conventional portable instrument stands for elongate instruments do not provide for a suspended support arrangement, relying instead on primarily supporting a base/body portion wherein the neck rests on a vertical-type support in a leaning fashion.
Another problem with conventional portable instrument stands is that when designed to be collapsible into a storage and transport configuration, such a stand, even when collapsed, typically remains bulky. Consequently, the collapsed instrument stand cannot easily be stored within the confines of, or compartments of, an instrument case or satchel.
SUMMARY
These and other problems are alleviated in an instrument stand in accordance with the present invention.
An instrument stand in accordance with the present invention provides a number of features not found in conventional portable instrument stands. An instrument stand in accordance with the present invention can support an instrument in a suspended fashion thereby imparting a minimum amount of stress to the instrument. In addition, an instrument stand incorporating the invention can be collapsed into a storage/transportation configuration that is substantially planar, thereby rendering the stand in a flat, low-profile orientation. Consequently, the instrument stand, in a collapsed state, can be stored within a compartment of an instrument case, or within the instrument case's main compartment.
In accordance with an exemplary embodiment of the invention, the instrument stand includes a base member for supporting and stabilizing the instrument stand when it is in use (i.e., the base member is deployed). The base member is attached to a base end of a first member, which first member is maintained in a generally vertical orientation when the stand is in use. The end of the first member opposite the base end, or head end, has a head member attached to it. When deployed for use, the head member is maintained in a position, and provides a means, whereby an instrument can be supported in a suspended manner. In a preferred embodiment, both the base and head members are pivotably connected to the first member with rotatable connectors. Detente mechanisms within the rotatable connectors secure the base and head members in a substantially orthogonal orientation relative to the first member when in a for-use configuration. In a collapsed configuration, the detente mechanisms retain the base and head members in a flush orientation so that the base, head, and first members are all substantially collateral and/or coplanar.
More particularly, a preferred exemplary arrangement involves an instrument stand that includes a first member having a base end and a head end. A base member is pivotably connected to the base end of the first member and maintains the first member in a substantially fixed, generally vertical orientation when the base member is in a deployed position. When collapsed for storage and/or transportation, the base member fold so as to be substantially planar with the first member. A head member is pivotably connected to the head end of the first member and is maintained in a substantially fixed orthogonal orientation relative to the first member when the head member is in a deployed position. When collapsed for storage and/or transportation, the head member folds up so as to be substantially planar with the first member and collapsed base member. A mechanism for hanging an instrument, such as a hook, or a strap spanning the head member can be provided, which hanging mechanism is capable of receiving an instrument so as to support the instrument in a suspended fashion. Alternatively, the head member can be specially configured to receive, and thereby suspend, a particular type of instrument.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, and other objects, features and advantages of the present invention will be more readily understood upon reading the following detailed description in conjunction with the drawings in which:
FIG. 1A depicts an exemplary instrument stand in accordance with the invention;
FIGS. 1B and 1C depict top and side views of the exemplary instrument stand of FIG. 1A when the instrument stand is in a collapsed configuration;
FIG. 2 depicts the components of a rotatable connector in an exemplary embodiment of the invention;
FIG. 3 depicts an exemplary instrument stand in accordance with the invention in a storage/transport configuration;
FIG. 4 depicts an exemplary head member configuration that conforms to the particular characteristics of an instrument;
FIGS. 5A and 5B depict exemplary configurations of instrument stand members at points where they contact one another when the stand is in a collapsed position;
FIG. 6 depicts an exemplary rotatable connector having a detente mechanism; and
FIG. 7 depicts an exemplary head member that is particularly configured to receive a specific type of instrument.
DETAILED DESCRIPTION
An exemplary instrument stand in accordance with the invention is depicted in FIG. 1A. The instrument stand 100 includes a base member 106 (shown in a deployed configuration) which is pivotably connected to a base end 109 of a first member 104 by a connector 110. When deployed for use, the base member 106 stably supports and thereby rigidly maintains the first member 104 in a generally upright position. A head end 107 of the first member 106 has a head member 102 (shown in a deployed configuration) pivotably connected thereto by a connector 108. In the exemplary embodiment shown, the head member 102 includes a strap 116 for suspending an instrument (not shown), such as a violin. The strap 102 may include a hook 118 for additionally hanging a bow (not shown).
A base member in a stand in accordance with an exemplary embodiment may include a multi-leg assembly including at least first and second extending rigid legs disposed at a relative angle from the first member 104, with a common couple connecting the legs and for supporting the first member 104. The multi-leg assembly may be tripod-like, in which case there can also be a third extending rigid leg. The tripod-like multi-leg assembly may be movable between a collapsed storage configuration, wherein the legs reside generally parallel to one another, and a for-use configuration wherein the legs are deployed so as to provide a stable support for the first member 104. Alternatively, the multi-leg assembly may include only first and second legs disposed at a relative angle, with each of the legs having disposed at the free end thereof, opposite the junction of the legs, a stabilizing foot or base member, thereby providing a stable base.
In a preferred embodiment, the base member 106 defines a sufficiently large swept area to provide stability to the instrument stand 100 when the stand is configured for use. The base member 106 can be configured to define any of a variety of hollow shapes having perimeters defining, for example, an oval, circle, "U" shape, "V" shape, or square. Preferably, a portion of the base member 106 opposite the connector 110 defines a gap 120, between end points 122 and 124 of the base member limbs. The purpose of the gap 120 is to permit the base member 106 to be folded into a storage, or transportation configuration, wherein the base member 106 is substantially flush, collateral with, or resides in a same plane as, the first member 104. When in a collapsed configuration, the first member 104 is received within the hollowed area 114 defined by the limbs of the base member 106, and also is received by the gap 120. The position of the base member 106 in a collapsed position is shown in phantom in FIG. 1A. FIG. 1B depicts a top view of the exemplary instrument stand 100 of FIG. 1A when the instrument stand 100 is in a collapsed configuration. FIG. 1C depicts a side view of the exemplary instrument 100 stand of FIG. 1A when the instrument stand 100 is in a collapsed configuration, and illustrates that the head member 102, base member 106 and first member 104 of an exemplary instrument stand 100 all reside substantially within a common plane in such a configuration.
The first member 104 is selected to have sufficient length to suspend the head member 102 above the base member 106 such that an instrument suspended from the strap 116 (or head member 102) can hang freely. In the case of a violin or viola, the length of the first member 104 may be dictated by the length of the violin or viola bow, rather than by the length of the violin or viola, itself. For aesthetic purposes, the shape of the first member 104 can be selected in accordance with personal tastes. For example, the first member 104 can be fashioned to resemble the curvature of the "f-hole" found in the body of a violin or viola.
In an exemplary embodiment, the head member 102 is devised to securely receive and suspend an instrument when the instrument stand 100 is configured for use. The head member 102 can be configured to define a variety of hollowed shapes such as a an oval, "U" or "V" shape. The hollowed portion of the head member 102 can include a means for hanging an instrument, such as the strap 116, which can receive a scroll of a violin by which the violin is suspended.
In a preferred embodiment, a portion of the head member 102 opposite the connector 108 defines a gap 130, between head member end points 132 and 134 of the head member limbs. The purpose of the gap 130 is to permit the head member 102 to be folded into a storage, or transportation configuration, wherein the head member 102 is substantially flush with, or resides generally in a same plane as, the first member 104 and the collapsed base member 106, shown in phantom. When in a collapsed configuration, the first member 104 is received within the hollowed area 136 defined by the limbs of the head member 102, and also is received by the gap 130. A collapsed head member, shown in phantom, depicts the head member 102 in a collapsed position. The gap 130 also acts to facilitate hanging of an instrument on the strap 116, as the neck of the instrument can pass through the gap 130.
Alternatively, the head member 102 can be selected or configured to uniquely receive, and thereby secure, a particular type of instrument. For example, as depicted in FIG. 4 a pair of spaced prongs 402 and 404 can be used that are positioned to receive the neck 406 of a guitar at an area 408 where the neck 406 connects to a portion of guitar's tuning-peg board 410. The guitar is suspended by the flared shoulders 414 at the base of the tuning peg board 410. The gap 412 between the spaced prongs 402 and 404 can receive a first member 416 when the head member is in a collapsed position.
In another embodiment of the invention, the base or and/or head member can define a hollow enclosure that has no gap. In such a case, it is preferable to have a groove, or inclusion at a point on the base or head member where the base or head member contacts the first member. As depicted in FIG. 5A, a groove or inclusion 502 is formed in the base or head member 508 that conforms to the cross-sectional profile of the first member 504 thereby permitting the base or head member 508 to fold flush with the first member 104 when the instrument stand is collapsed into a storage/transport configuration. Alternatively, a groove can be formed in the first member 504 to receive a cross-sectional profile of a base or head member at the point of contact, or, as shown in FIG. 5B both the base/head member 508 and the first member 504 can have matched inter-meshing grooves 510 and 506, respectively.
Referring again to FIG. 1A, the base member 106 and head member 102 are connected to the first member 104 by connectors 110 and 108, respectively. FIG. 2 depicts a disassembled exemplary connector arrangement 200 involving a friction hinge. An end portion of a first member 204 is connected to a tubular outer sleeve 210 by gluing, welding, brazing, or like fusing. A connecting shaft 208 is ensconced within the outer sleeve 210 and rotatable therewithin. Shaft ends 216 and 218 receive end portions 206 and 202 of tubing from which the limbs of the base and/or head members are formed. An inner tube portion 224 of end portion 206 is fit over the shaft end 216 and fixed thereto by a press-fit pin 212 that is inserted through a tubing hole 220, which press-fit pin 212 is secured within a shaft hole 226. End portion 202 is similarly fixed to the shaft end 218 by inserting a press-fit pin 214 through tubing hole 222 and securing the press-fit pin 214 within shaft hole 228.
In an arrangement incorporating the hinge of FIG. 2, the base and/or head member is fixed in a selected position by virtue of friction between an outer surface of the connecting shaft 208 and an inner surface 230 of the tubular outer sleeve 210. However, alternative exemplary embodiments can incorporate other hinging mechanisms that include detente mechanisms for fixing the head and base members in a deployed position for use, or in a collapsed position for storage and transportation. Such a detente mechanism can involve a connector whereby a base or head member is fixed in a for-use configuration in a substantially orthogonal position relative to the first member. When not deployed for use, a head or base member can rotate marginally under inherent friction within the connection mechanism. However, when completely deployed into a for-use position, the base/head member (or the first member), is rotated to render it and the first member in substantially orthogonal positions relative to one another.
In an exemplary embodiment, at the rotation point where the base or head member achieves a desirable deployed position, a ratchet engages a catch within the connector thereby securing the member in a from returning to a storage position. To disengage the ratchet mechanism, the member can be rotated beyond the in-use position whereby the ratchet is released, allowing the member to rotate marginally toward the storage position. Such a mechanism is not unlike that found in foldable beach chairs whose back rests can be incrementally ratcheted toward a more and more upright position until the backrest is beyond a vertical point. At such a point, the ratchet mechanism is released thereby allowing the backrest to recline fully.
Another possible connection detente mechanism in an instrument stand in accordance with an exemplary embodiment of the invention, can involve one or more spring-loaded ball bearings that are received by an inclusion or groove at an appropriate detente position. As applied in a connector 600 of FIG. 6, spring loaded ball-bearings 602 can partially protrude from a surface 610 of the connecting shaft 608. A groove 632 formed on an inner surface 630 of a tubular outer sleeve can positioned to receive the spring-loaded ball bearings 602. The position of the groove 632 in the outer sleeve can be selected so as to detain a member in either a storage/transport or for-use position. A second groove can be formed so that a member can be detained in both storage and deployed positions. Rotation of a member can be further restricted by forming the connection so that a member can rotate only over a restricted 90° range, for example. At each extreme of the range, the member can be detained by a spring-loaded ball bearing, friction, ratchet, or other suitable mechanism to substantially fix the member in position.
Yet another possible detente mechanism for maintaining the base and/or head member in position is an insertable pin that can prevent member rotation when the pin is inserted in place. For instance, a hole formed within a the connector portion of a head member is positioned so as to be aligned with a corresponding hole within the connector portion of the first member when the head member is in a desired deployment position. Once aligned, the user inserts the pin to fix the head and first members relative to one another and thereby prevent further rotation. The pin can be tethered to the instrument stand in the region of the connector so as to prevent its loss when not in use. Furthermore, a storage position hole can also be formed in the connector portion of the first member that corresponds to fixing the base or head member in a collapsed position. When the pin is inserted the member is prevented from further rotation.
In accordance with an instrument stand incorporating the invention, an instrument is supported by the head member in a suspended fashion. This can be achieved in a variety of ways. As depicted in FIG. 1, a strap 116 spans the arms of the head member. The strap can, for example, receive and support the scroll of a violin. The violin bow can be hung from a hook 118. In accordance with alternative embodiments, the head member can be shaped to conform to, and thereby support, an instrument in accordance with the instrument's particular physical attributes. For example, a head member can be formed to conform to the cross sectional width of a saxophone tube piece located proximal to the mouth piece of the saxophone. As depicted, for example, in FIG. 7, such a head member 702 may be a U-shaped piece having a rubber, or other soft-grip coating, that clinches the saxophone tube 704 when the saxophone is suspended by the head member 702 of the instrument stand 700.
Another aspect of an instrument stand in accordance with the invention is the instrument stand's ability to be collapsed, or folded, into a substantially flat, or planar, configuration for storage and/or transportation wherein the base, first and head members are generally collateral and coplanar to one another. This capability offers the advantage that the instrument stand can be stored within an instrument case, or in an outer compartment, such as a music pocket, of the instrument case. Conventional instrument stands also collapse into a storage and transportation configuration, however, such configurations typically remain bulky and unfit for storage within an instrument case or a compartment thereof. As depicted, for example, in FIG. 3, a violin stand 300 in accordance with the invention can be stored in a music pocket 302 of a violin case 304.
In accordance with another feature of the invention, the first member can be telescopic. This permits the instrument stand to be further collapsed to reduce its collapsed length. The telescopic sections can be fixed in a for-use position by use of friction clinching between distal ends of consecutive tube sections, twist clinching of the same, mating circumferential grooves and dimples at respective tube ends, or any other like fixing means that maintain the first member in a rigid state when the instrument stand is in use.
An instrument stand in accordance with the invention can be fabricated from any of a variety of suitable materials. It is generally preferable that the stand be made of light weight materials in view of its portability. Suitable materials may include lightweight metal tubing, such as aluminum. Plastic, fiberglass or like materials may also be used. The thickness of the tubing is selected in view of strength and rigidity requirements of the instrument stand. Tubing used for the base member may be solid, or be filled with sand, or like material, to add stability to the stand when in use.
Because an instrument can be suspended in a manner that may permit it to swing about its support point, it may be desirable to fabricate the first member from a material that is less prone to dent or mark the instrument in the event of contact therebetween. In the case where the first member is made of a hard material, such as metal, it may be desirable to locate padding over the entire first member, or position padding at one or more likely contact points for protection of the instrument in the event of contact between the instrument and the first member.
It will be appreciated by those skilled in the art that the orientation of the first member can be slightly tilted when the instrument stand is in a for-use configuration. Accordingly, a head member, when fixed in a for-use configuration need not be exactly orthogonal, relative to the first member, because of the first member's tilted orientation. Nevertheless, the arrangement permits an instrument suspended from the stand to hang freely without additional contact with the first member, which contact may be possible with awkwardly weighted instruments such as saxophones.
The invention has been described with reference to particular embodiments. However, it will be readily apparent to those skilled in the art that it is possible to embody the invention in specific forms other than those of the embodiments described above. Embodiment of the invention in ways not specifically described may be done without departing from the spirit of the invention. Therefore, the preferred embodiments described herein are merely illustrative and should not be considered restrictive in any way. The scope of the invention is given by the appended claims, rather than by the preceding description, and all variations and equivalents which fall within the range of the claims are intended to be embraced therein.
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A collapsible instrument stand for suspending an elongate instrument in a vertical orientation. The instrument stand generally includes three basic members: a base member which supports the stand, a head member from which an instrument is suspended, and a first member which rigidly supports the head member. The base and head members are preferably attached to respective ends of the first member in a pivotable manner. When configured for use, the base and head members are folded out to be generally orthogonal to the first member. When configured for storage and/or transportation, the base and head members are folded to become flush with, and generally be collateral and/or coplanar with the first member. In the latter configuration, the instrument stand can be stored within a flat outer compartment of an instrument case, if not within the instrument case itself.
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FIELD OF THE INVENTION
This invention relates to the packaging of materials used in the sealing of mechanical and electrical services (pipes, cables and conduits, etc.) that pass through floors and walls so as to reduce the spread of fire. More particularly, this invention relates to an assembly of materials suitable to effect installation of a fire-stop barrier, and to the organization of such materials into a kit that is efficient and convenient for both the supplier and the end user.
BACKGROUND TO THE INVENTION
It has become conventional to pack the holes in buildings that are penetrated by mechanical and electrical services with fire-stop materials. This is particularly true where holes for pipes penetrate through concrete floors and walls.
In such cases the holes that are cast or drilled in place are always significantly larger than the pipes that are intended to pass therethrough. This permits small misalignments of the pipes to be accommodated.
The gap between the pipe and perimeter of the hole is then packed with materials to resist the transfer of fire across the fire barrier created by the wall or floor. In the United States a typical industrial standard set for fire-stop materials that perform this function is the test standard ULI 1479 set by Underwriters Laboratories Ltd. Many architects specify for fire-stop materials that meet this standard.
A satisfactory fire-stop arrangement has previously been established using a combination of mineral wool packing and an intumescent silicone sealant (usually a self-levelling, or gun-grade, room temperature vulcanizing-RTV sealant) that is applied as an elastomeric caulk to contain the mineral wool packing and create an air-tight seal. This sealant must bond sufficiently to the pipe and hole to resist washing-out, as where water from fire hoses floods a floor in a building.
Customarily, the silicone sealant has been marketed in extrudable tubes. As such sealants are moisture-curing, they will, once opened, have only a limited life-time. Since such sealant is an expensive material, it has been found efficient to supply it in multiple, sealed units or tubes of moderate volume.
The mineral wool used for packing is inherently nonflammable. It serves to insulate gaps between pipes and hole perimeters and acts as the fire-stop. The sealant, applied to the top surface of the wool for floor penetrations, and on both sides of the wool for wall penetrations, serves to block smoke and prevent air flow.
In a typical case of a 6 inch diameter hole filled with a 4 inch pipe a gap of approximately one inch will exist around the pipe. The mineral wool is packed into this gap, usually to a required minimum length (extending along the pipe) according to the fire rating that is desired, e.g., a 2 hour rating may require 114 mm or 41/2 inches of wool. The gap at the places where the pipe exits the hole is then sealed with the sealant, to a specified depth, typically 6 mm or about one-quarter of an inch, in order to meet the approved standard. The wool should be placed close to the end of the hole to support the sealant and provide a guide to ensure that a proper, minimum depth of sealant is applied.
All fire-stop design listings (Underwriter's Laboratories and Factory Mutual approvals) indicate that specific tested fire-components, when applied according to the prescribed methods, constitute the approved fire-stop system. When sealant and mineral wool are purchased separately, there is no certainty that the approved combination of material will be selected. This invention ensures that the specifically approved combination of fire-stop components to meet such standards are delivered to the end user.
It has been found by the inventor herein that a typical worker can install fire-stop for about 25-30 average floor penetrations in a four hour shift. This consumes around 16 feet of four inch thick, two inch wide, compressible mineral wool batting; and about 6 tubes of 300 ml, (or 10.1 fluid ounces), of silicone caulking.
Workmen on a job site conveniently require as tools for installation of this type of fire-stop:
(1) a caulking gun--to force sealant from the tube;
(2) a knife--to open the sealant tube;
(3) a mask and gloves--for protection; and
(4) a stick--for pressing the mineral wool into place.
Items (3) and (4), to the extent that they have been provided to workmen in the past, have been treated as consumables and are thrown away after a short period of use. Item (2) is often assumed to be provided by the workman, and item (1) has often been considered reusable, although caulking guns are often lost on the job site, as are other tools.
Against this background the inventor has recognized that the delivery and consumption of fire-stop materials can be rendered more convenient and efficient by means of assembly of a specific "kit" of materials, and its delivery in a convenient packaging format.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention will then be further described, and defined, in each of the individual claims which conclude this Specification.
SUMMARY OF THE INVENTION
The invention in its broadest sense consists of a kit of fire stop materials for sealing penetrations through walls or floors, packaged in a single box, comprising:
(1) a supply of mineral wool;
(2) a supply of intumescent sealant; and
(3) at least one tool for installing the sealant in the form of a caulking gun,
wherein the amount of sealant in the kit is proportional to the amount of mineral wool in accordance with the respective amounts of such materials to be consumed for each penetration to be sealed. Preferably, in the case of a floor kit, this proportion is in the range of 60 to 90 ounces of sealant for 1500 to 1600 cubic inches of mineral wool in its fully expanded condition. In the case of a wall kit the same preferred proportions would be applied to half as many holes, packing wool and applying sealant from both sides.
More specifically, in a preferred embodiment, the sealant is supplied in the form of six 300 ml (10.1 oz) size tubes of sealant to 16 feet of four inch thick, two inch wide mineral wool batting.
As a preferred embodiment the components of the kit are packed in a box wherein the mineral wool is cut, preferably into eight pieces of 2 inch wide, 4 inch thick and 24 inch long strips arranged centrally within the box, to form a rectangular volume that is bounded by sealant tubes at both ends. Preferably such tubes are symmetrically placed on either side of the mineral wool, and are snugly held between the mineral wool and the box ends to prevent such tubes from being loose within the box. Optionally, the mineral wool may be compacted by vacuum storage in a hermetically sealed outer covering, such as polyethylene film, to reduce the overall volume of the box.
As a further optional but preferred embodiment, the box provides an overhead storage space above the mineral wool. The tool for installing the sealant is placed in such overhead storage space. As a preferred feature, this overhead storage space contains as tools:
(1) a caulking gun--to force sealant from the tube;
(2) a knife--to open the sealant tube;
(3) a mask and gloves--for protection; and
(4) a stick--for pressing the mineral wool into place, optionally embossed with guide marks for determining correct mineral wool placement.
As a further optional feature the mineral wool is surrounded by a cardboard liner that provides a protective wall between the sealant tubes and mineral wool, and extends upwards for the full height of the box to define an inner storage area within the overhead storage space wherein the tool or tools identified above are placed.
As a further optional feature, the box is provided with handle openings that pierce the longitudinal sides of the box and the liner centrally, at a location that is in-line with the overhead storage space.
In summarizing the invention above, and in describing the preferred embodiments below, specific terminology has been resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
SUMMARY OF THE FIGURES
FIG. 1 is a perspective view of a box containing a kit of fire-stop materials.
FIG. 2 is a top view of the box of FIG. 1.
FIG. 3 is a front sectional view of FIG. 3,
FIG. 4 is an exploded view of the various tools that may be placed in the kit.
FIG. 5 is a side view of the box showing the placement of openings that serve as handles.
FIG. 6 is a cross-sectional view of a floor pierced by a pipe sealed by mineral wool packing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a box 1 with upper flaps 2 that can close to form a lid contains strips of mineral wool 3. The box 1 is preferably formed with panels of corrugated paperboard. Inside the box 1 is a liner 4 consisting of a rectangular four-sided paperboard wall 5 that encloses the mineral wool 3. The liner 4 is of the same full height as the outer side walls 6 of the box 1. This provides strength to permit boxes to be stacked.
The liner 4 is centrally located between the ends 7 of the box 1. The mineral wool 3 is filled to a level 8 within the box 1 that is short of the upper edge 9 of the box. This forms an inner overhead storage space 10 in which a tool, at minimum a caulking gun", or tools may be placed for storage and delivery.
The liner 4 occupies the full width of the box 1 in one, shorter transverse direction. In the other longer longitudinal direction, the liner 4 defines two symmetrical, compartments 12 located between the box and side walls 7. These compartments 12 contain sealant tubes 13 that are snugly fitted between the liner wall 5 and the box end walls 7. This tight fit prevents the tubes 13 from shifting within the box 1 during transportation. The wall 5 of the liner 4 also protects the mineral wool 3 from being damaged by the shifting of the tubes 13.
A variety of tools may be placed within the inner overhead space 10 inside the box 1. As shown in FIG. 4 these may include gloves 14, a mask 15, a knife 16, a stick 17 and a caulking gun 11. Preferably the gloves 14 are made of an absorbant material, such as cotton, to permit the gloves 14 to be used to wipe and clean surfaces to be sealed by the silicone caulking.
In FIG. 5 handle openings 18 are formed centrally in the two longitudinal side walls 6 at the height of the overhead storage space 10, passing through the wall 5 of the liner 4. These openings 18 are formed by cutting flaps 19 that are folded inwardly along a fold-line 20. The openings 18 may optionally extend through the wall 5 of the liner 4 into the inner, overhead storage space 10, or may pass only through the outer side walls 6 of the box 1. These folded flaps 19 provide a grasping surface for fingers inserted into the handle openings 18. In the case where the flaps extend through the liner, the walls 21 lying above the handle openings 18 are of double thickness and, therefore, are of increased strength, suitable to support the weight of the kit. Where only the outer walls 6 are pierced, the liner 4 blocks fingers inserted in the openings 18 from contacting the mineral wool 3.
Because the tubes 13 are symmetrically placed about the handle openings 18, the box 1 will be balanced when lifted or stacked for storage. As the handle openings 18 penetrate into the head space, when fingers are inserted therein, such fingers will not contact the mineral wool 3.
In use the materials in a typical floor kit are installed in the conventional manner to meet the predetermined fire retardancy standard. As shown in FIG. 6, a pipe 23 passes through a hole 24 in a concrete floor 25, leaving a gap 26. This gap 26 is filled to a minimum depth, preferably 114 mm or 4 1/2 inches for a 4 inch pipe, by mineral wool 27 which is recessed by 12.7 mm or 1/2 inch from the top of the floor slab. To meet fire retardancy standards, the wool 27 may be required to be compacted to 50% of its non-compacted volume.
A layer of intumescent sealant 28 is laid over the mineral wool 27, to a preferred minimum depth of 6 mm or one-quarter of an inch, leaving a slight recess below the floor to protect the sealant.
The knife 16 is used to cut the mineral wool fibre battings to the correct size. The stick 17 is used to press the wool 27 into place. As a guide to the placement of the mineral wool 27 the stick 17 may be embossed with markers 29, 29a that indicate the preferred depths for the bottom and top of the mineral wool 27.
By assembling all of the components, in balanced proportions, and placing them in a box in the manner indicated, a kit is provided that contains all of the components needed by a workman to carry-out a series of fire-stop installations in a normal working period. While a number of components, particularly the tools provided in the kit as throw-away items are normally conserved, it has been found that the convenience and efficiency of the kit justifies this expense.
CONCLUSION
The foregoing has constituted a description of specific embodiments showing how the invention may be applied and put into use. These embodiments are only exemplary. The invention in its broadcast, and more specific aspects, is further described and defined in the claims which now follow.
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A kit of fire-stop materials contains balanced proportions of sealant and mineral wool. Boxed with tools with a layout that renders transportation and storage convenient, the efficiency of the system makes the package cost effective.
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BACKGROUND OF THE INVENTION
[0001] The rental of digital content on physical media is a business methodology that has been exploited for many years by large companies such as Block Buster and Netflex. DVD movies rented out by these companies typically include movie trailers and other targeted ads intended to sell products and services. These ads and movie trailers represent a secondary revenue stream to the rental business. One shortcoming of the rental business however is the trailers and ads placed on the DVDs become stale after a period of time. Trailers for movies that will be released to theaters are still seen by customers renting the DVDs long after the theater movies are themselves released to DVDs. The present invention provides a methodology that will allow DVD rental companies to freshen the movie trailers and targeted ads they place on the media. Additionally, this methodology allows the company to more closely target trailers and ads to specific customers based on different demographic data associated with the customer. The present invention gives the rental companies a way to maximize their return on investment and to enhance their revenue stream.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] Embodiments of the present invention are illustrated by way of example, and not by way of limitation. The following figures and the descriptions both brief and the detailed descriptions of the invention refer to similar elements and in which:
[0003] FIG. 1 is a diagram depicting how the metadata is formatted for placement onto optical media for successive rentals.
DESCRIPTION OF THE INVENTION
[0004] Now referencing FIG. 1 , 10 depicts a methodology for changing metadata on optical media. This embodiment addresses a problem where write once optical media which is typically used for rental DVDs. Write-once media typically does not work well in an environment where some of the data needs to be changed many times—here prior to, during or and/or after each rental. Write once media however can have multiple sessions or partitions created one at a time in a serial fashion. In this type of embodiment, several megabytes of space on the media can accommodate hundreds of additional sessions containing small amounts of data. Considering that the space requirements for such data as rental period metadata consume on the order of tens to hundreds of bytes of data, the number of additional sessions that could be written would exceed the usable life span of rental cycles. For example, single pieces of DVD write once media may initially have Digital Content File 11 written on it and Session 1 Rental Period Metadata File 12 written. When the media is returned by a user, Session 2 Rental Period Metadata File 15 can be written as the next session prior to the media being sent to the next customer. This embodiment allows the media distributor to change the rental period rules at will. It also allows for the refreshing of metadata that may contain data other than rental period data. For example, the metadata may contain updated movie trailers and targeted ads that are specifically targeted to the next customer that will receive the media. The metadata can include executable code that operates an application, e.g. an application that is specific to the next renter.
[0005] The general structure and techniques, and more specific embodiments which can be used to effect different ways of carrying out the more general goals are described herein.
[0006] Although only a few embodiments have been disclosed in detail above, other embodiments are possible and the inventors intend these to be encompassed within this specification. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way. This disclosure is intended to be exemplary, and the claims are intended to cover any modification or alternative which might be predictable to a person having ordinary skill in the art. For example, other kinds of media and players are contemplated, including newer players such as Bluray or HD-DVD.
[0007] Also, the inventors intend that only those claims which use the words “means for” are intended to be interpreted under 35 USC 112, sixth paragraph. Moreover, no limitations from the specification are intended to be read into any claims, unless those limitations are expressly included in the claims. The computers described herein may be any kind of computer, either general purpose, or some specific purpose computer such as a workstation. The computer may be an Intel (e.g., Pentium or Core 2 duo) or AMD based computer, running Windows XP or Linux, or may be a Macintosh computer. The computer may also be a handheld computer, such as a PDA, cell phone, or laptop.
[0008] The programs may be written in C or Python, or Java, Brew or any other programming language. The programs may be resident on a storage medium, e.g., magnetic or optical, e.g. the computer hard drive, a removable disk or media such as a memory stick or SD media, wired or wireless network based or Bluetooth based Network Attached Storage (NAS), or other removable medium. The programs may also be run over a network, for example, with a server or other machine sending signals to the local machine, which allows the local machine to carry out the operations described herein.
[0009] Where a specific numerical value is mentioned herein, it should be considered that the value may be increased or decreased by 20%, while still staying within the teachings of the present application, unless some different range is specifically mentioned. Where a specified logical sense is used, the opposite logical sense is also intended to be encompassed.
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Write once media is used to store many different versions of metadata along with recorded video program. The metadata can be written many times over, for example once for each renter. The metadata can include rental information, or movie trailers, or other information.
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[0001] The present application claims priority from Japanese application JP 2006-044887 filed on Feb. 22, 2006, the content of which is hereby incorporated by reference into this application.
FIELD OF THE INVENTION
[0002] The present invention relates to a semiconductor laser diode and an integrated optical waveguide device in which the semiconductor laser diode and an optical modulator are integrated.
BACKGROUND OF THE INVENTION
[0003] Recently, it is becoming increasingly important to reduce power consumption and cost of a semiconductor laser diode and an integrated semiconductor optical waveguide device in which a semiconductor laser diode and an electroabsorption type optical modulator are integrated. For the semiconductor laser diode, there are mainly ridge type and buried heterostructure type, of which the ridge type is advantageous for cost reduction because of its easier fabrication and smaller number of growth steps and is actively developed for use in both information and communication. The ridge type semiconductor laser diode is formed by laminating a lower clad layer, multiple or single well layer, upper clad layer, and ridge on a substrate formed of n-type semiconductor. An integrated semiconductor optical waveguide device (EA/DFB) is constructed by integrating this ridge type semiconductor laser diode and an electroabsorption type optical modulator with ridge on a common substrate.
[0004] In the field of information, high speed recording of information is demanded in accordance with an increase in the amount of information to be recorded, resulting in an increasing need for a higher power semiconductor laser diode. Although this may be met by increasing an operating current, it is disadvantageous for reduction in power consumption. On the other hand, in the field of communication, the mainstream transmission speed in current backbone network and metro network is 2.5 Gbps or 10 Gbps. Therefore, a structure of integrated semiconductor optical waveguide device in which an optical modulator is monolithically integrated for high speed modulation of a transmitter is advantageous for reduction in cost. However, power consumption increases with an increase in transmission distance as well as with the use of higher bit rate. With the aim of reducing the power consumption, the development of an electroabsorption modulator integrated distributed feedback laser (EA/DFB) that does not require temperature control between −5 degree C. and 85 degree C. has been pursued (Non-patent document 1: OFCNFOEC OFC POSTDEADLINE PAPERS Thursday, Mar. 10, 2005 PDP14). In order to achieve this, further enhancement in optical power of a semiconductor laser diode under a constant operating current is needed. Thus, the enhancement in optical power under a constant operating current is required for the reduction in power consumption of a semiconductor laser diode for use in both information and communication.
[0005] One method of power enhancement of a semiconductor laser diode is to widen its ridge width. Since the amount of heat generated becomes larger in general as the operating current in a semiconductor laser diode is raised, optical power is saturated at a certain current level, thereby making it impossible to obtain enough output. On the other hand, an electric resistance at the time of current injection into a semiconductor laser diode whose ridge width is widened is lowered, the amount of heat generation is correspondingly suppressed, and the saturation current is enhanced. As the result, the saturation output is also enhanced, and the optical power at a constant operating current is increased. The widening of the ridge width can be realized by forming an upper buffer layer between an upper clad layer and the ridge. An average refractive index difference in the lamination direction between the portion including the ridge and the portion not including the ridge becomes smaller by forming the upper buffer layer compared to when the upper buffer layer is not provided, and so-called cut-off width referred in the slab waveguide is increased, which makes it possible to widen the ridge width in lateral single mode.
[0006] As another method of the power enhancement, there is a method to suppress a rise of threshold current of a semiconductor laser diode. When the threshold current is low, optical power at a constant operating current rises, and thus the power enhancement of a semiconductor laser diode can be realized. As the method to suppress the rise of the threshold current, for example, there is a method disclosed in JP-A No. 214372/2004 (Patent document 1). In this method, a cover layer injected with Fe is formed by regrowth in both side directions of the ridge of a conventional ridge type semiconductor laser diode formed of InP series such as InP, InGaAsP and InGaAlAs, and this is used as an Fe supply source to an upper clad layer. The upper clad layer is made insulative, thereby suppressing diffusion of current injected from the ridge in the upper clad layer and a rise of the threshold current. When these lasers are made to function as a distributed feedback (DFB) type, a diffraction grating has been conventionally fabricated in an upper portion of n-substrate, a multiple well layer, or an upper buffer layer.
[0007] On the other hand, as for EA/DFB, for example, a semiconductor optical waveguide device in which a buried heterostructure type semiconductor laser diode and a ridge type electroabsorption type optical modulator are integrated differs in mode expansion in each portion, and therefore, a method of integrating the buried heterostructure type and the ridge type by tapering each joint portion is proposed in JP-A No. 78792/1996 (Patent document 2). Further, a method in which the light emitting side of a semiconductor optical waveguide device is tapered to make light coupling to fiber better is proposed in JP-A No. 66046/2000 (Patent document 3). However, no semiconductor optical waveguide device integrated with a high power laser in which ridge is widened or threshold current is lowered as described above has been disclosed.
[0008] As described above, the insertion of the upper buffer layer between the upper clad layer and the ridge is effective for power enhancement of a semiconductor laser diode, whereas there has been a problem that lateral diffusion of carrier becomes larger particularly on the p-side and the threshold current is increased. Further, since the average refractive index difference between the portion including the ridge and the portion not including the ridge becomes smaller, mode shape laterally expands, and far field pattern expansion becomes markedly different between in the horizontal direction and in the vertical direction, resulting in being asymmetrical. This causes an increase in loss of coupling to an exterior such as fiber.
[0009] To suppress the above-described rise of the threshold current, the application of the method disclosed in Patent document 1 is conceivable. However, this method requires crystal regrowth to form a cover layer. Therefore, it is disadvantageous in terms of cost reduction, and further, the application of the method is limited to InP-substrate based laser diodes, making it impossible to apply to semiconductor laser diodes formed of other materials such as GaAs-substrate based laser diodes.
[0010] For a high power semiconductor laser diode, it is effective to insert the upper buffer layer between the upper clad layer and the ridge to widen the ridge width. The application of this method to an integrated semiconductor waveguide device such as EA/DFB created another problem. For example, for power enhancement of a semiconductor laser diode, when the ridge width of a semiconductor laser diode is set to 2 μm, the capacitance increases and the band decreases in an electroabsorption type optical modulator portion. On the other hand, when the ridge width of the semiconductor laser diode is set to 1.4 μm in accord with the ridge width of 1.4 μm of the electroabsorption type optical modulator portion, the thermal characteristic of the semiconductor laser diode deteriorates and high output cannot be obtained. Therefore, as a trade-off value, the ridge width of EA/DFB has been set to ca.1.6 μm for integration which deviates from an original optimal ridge width and at which an overall characteristic deteriorates but each of the semiconductor laser diode and the electroabsorption type optical modulator can fulfill its function with ease.
[0011] Further, the insertion position of a diffraction grating also affects laser characteristics. A conventional position for fabrication of a diffraction grating has been in an upper portion of n-substrate, a multiple well layer, or an upper buffer layer. When the diffraction grating is inserted into the multiple well layer or the upper buffer layer, regrowth is carried out after forming the diffraction grating. However, a change in carrier concentration occurs at the regrowth interface, resulting in trapping of carrier, which causes deterioration of a characteristic in respect of power enhancement. On the other hand, when the diffraction grating is fabricated in the upper portion of n-substrate, the above problem can be ignored but wavelength controllability deteriorates because the diffraction grating has been formed before a multiple well layer is formed.
[0012] As described above, the above methods have not yet reached a point where reduction in power consumption and reduction in cost are compatible with each other. In addition, the design of a semiconductor laser diode and an electroabsorption type optical modulator, particularly ridge width thereof, is subject to limitation for integration, and each device has not been able to be integrated under optimal conditions.
SUMMARY OF THE INVENTION
[0013] The present invention accomplishes a high power semiconductor laser diode. Further, the present invention achieves reduction in power consumption of an integrated semiconductor optical waveguide device in which the semiconductor laser diode enhanced in output power is integrated with an electroabsorption type optical modulator as well as reduction in cost of the integration without deteriorating each characteristic of the semiconductor laser diode and the electroabsorption type optical modulator.
[0014] First, the semiconductor laser diode is formed from a lower clad layer, a multiple or single well layer, an upper clad layer, an upper buffer layer, and a ridge on an n-type semiconductor substrate. Further, insulative grooves with a low refractive index that are cut into the upper buffer layer along both sides of the ridge are formed, thereby suppressing lateral diffusion of current injected from the ridge. Owing to this, a rise of threshold current is suppressed.
[0015] In the semiconductor laser diode constructed from the lower clad layer, the multiple or single well layer, the upper clad layer, the ridge, and the like on the n-type semiconductor substrate, a diffraction grating is formed, in the ridge, of a semiconductor material having a refractive index higher than that of a semiconductor material mainly constituting the ridge. In this way, the ridge is manufactured without characteristic deterioration caused by contamination of impurities and a change in carrier concentration due to regrowth after forming the diffraction grating, compared to when the diffraction grating is formed on the upper clad layer.
[0016] On the other hand, in an integrated semiconductor optical waveguide device such as EA/DFB, the respective ridges of the semiconductor laser diode and an electroabsorption type optical modulator provided with a ridge are connected by a waveguide having a ridge in a tapered form.
[0017] According to the present invention, a semiconductor laser diode having a high output power and a low threshold current can be realized. At the same time, in an integrated semiconductor optical waveguide device such as EA/DFB, the semiconductor laser diode and the electroabsorption type optical modulator can not only be made to exhibit their respective characteristics maximally but also be integrated at low cost while suppressing anisotropy in the expansion of the far field pattern of emitting light in the vertical direction and the horizontal direction with low loss of light and without increasing the growth cycle at the time of integration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a diagram to explain the first half of a fabrication process of a semiconductor laser diode having an upper buffer layer as the premise of the present invention, where FIG. 1A , FIG. 1B , FIG. 1C , and FIG. 1D show successive steps of the process;
[0019] FIG. 2 is a diagram to explain the second half of the fabrication process of the semiconductor laser diode having the upper buffer layer as the premise of the present invention, where FIG. 2A , FIG. 2B , and FIG. 2C show successive steps of the process, and FIG. 2C represents a completed state of the semiconductor laser diode;
[0020] FIG. 3 is a graph showing a comparison result of operation characteristic of a semiconductor laser diode without the upper buffer layer constructed in almost the same structure as that of the semiconductor laser diode as the premise of the present invention;
[0021] FIG. 4 is a diagram to explain the first half of a fabrication process of a semiconductor laser diode of Embodiment 1 of the present invention using the structure in FIG. 2A as a starting point, where FIG. 4A , FIG. 4B , FIG. 4C , and FIG. 4D show successive steps of the process;
[0022] FIG. 5 is a diagram to explain the second half of the fabrication process of the semiconductor laser diode of Embodiment 1 of the present invention, where FIG. 5A , FIG. 5B , FIG. 5C , and FIG. 5D show successive steps of the process;
[0023] FIG. 6 is a diagram representing a completed state of the semiconductor laser diode of Embodiment 1 of the present invention;
[0024] FIG. 7A is a graph to explain characteristics of the semiconductor laser diode of Embodiment 1;
[0025] FIG. 7B is a characteristic graph showing evaluated relation of groove width in the upper buffer layer and cut-off width;
[0026] FIG. 8 is a diagram showing a fabrication process of a semiconductor laser diode of Embodiment 2 of the present invention realized by a structure starting with an n-type GaAs semiconductor substrate, where FIG. 8A , FIG. 8B , and FIG. 8C shows main successive steps of the process, and FIG. 8C represents a completed state of the semiconductor laser diode;
[0027] FIG. 9 is a diagram showing the first half of a fabrication process of an integrated optical waveguide device of Embodiment 3 of the present invention, where FIG. 9A , FIG. 9B , FIG. 9C , FIG. 9D , and FIG. 9E show successive steps of the process;
[0028] FIG. 10 is a diagram showing the second half of the fabrication process of the integrated optical waveguide device of Embodiment 3 of the present invention, where FIG. 10A , FIG. 10B , FIG. 10C , and FIG. 10D show successive steps of the process;
[0029] FIG. 11 represents a completed state of the integrated optical waveguide device of Embodiment 3 of the present invention;
[0030] FIG. 12 is a graph showing evaluation results of characteristics of the integrated optical waveguide device of Embodiment 3 of the present invention when the ridge widths of semiconductor laser diodes were 2.0 μm and 2.5 μm, respectively, and the ridge width of an electroabsorption type optical modulator was 1.4 μm, where the waveguide length was taken on the horizontal axis and the transmittance was taken on the vertical axis; and
[0031] FIG. 13 is a diagram representing a completed state of an integrated optical waveguide device of Embodiment 4, where a Mach-Zehnder type optical modulator was employed in place of the electroabsorption type optical modulator in the integrated optical waveguide device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Hereinafter, preferred embodiments of the present invention are explained with Embodiments 1 to 5 with reference to related drawings.
Embodiment 1
[0033] Embodiment 1 in which the present invention was applied to a 1.5 μm-wavelength band ridge waveguide type semiconductor laser diode is explained first. It should be noted that the figure size and the scale described in Embodiment 1 do not necessarily correspond proportionately. A semiconductor laser diode having an upper buffer layer as the premise of the present invention is explained using FIGS. 1 and 2 , and then an embodiment of a semiconductor laser diode of the present invention in which insulative grooves with a low refractive index that were cut into the upper buffer layer along both sides of the ridge were formed is explained.
[0034] As shown in FIG. 1A , on an n-type InP semiconductor substrate 1 (thickness 2 mm), an n-type InP buffer layer 2 (thickness 0.15 μm), a lower clad layer 3 (thickness 0.13 μm) formed of n-type InGaAsP series, a multiple-quantum well active layer 4 (thickness 0.114 μm) in which a well layer formed of InGaAsP (thickness 7 nm, compositional wavelength 1.3 μm) having 1.0% compressive strain and a barrier layer formed of InGaAsP (thickness 12 nm, compositional wavelength 1.3 μm) having 0.5% tensile strain were laminated by 6 cycles, an upper clad layer 5 (thickness 0.1 μm) formed of InGaAsP series, an upper buffer layer 6 (thickness 0.2 μm) formed of p-type InP, an etching stop layer 7 (thickness 5 nm) formed of InGaAsP series, a lower spacer layer 8 (thickness 20 nm) formed of InP, and a diffraction grating layer 9 (thickness 30 nm) formed of InGaAsP series were laminated by metal organic chemical vapor deposition (MOCVD). In this embodiment, the emission wavelength of the multiple-quantum well active layer was about 1.5 μm.
[0035] Next, as shown in FIG. 1B , a diffraction grating was formed on the diffraction grating layer 9 by a known interference exposure method and subsequent etching using a phosphoric acid based solution. Since in Embodiment 1, the InP spacer layer 8 was provided between the etching stop layer 7 and the diffraction grating layer 9 , the diffraction grating became a floating type and could be fabricated with high precision even if etching time varied somewhat in every fabrication.
[0036] Subsequently, as shown in FIG. 1C , a p-type InP layer 10 (thickness 2.0 μm) and a contact layer 11 (thickness 0.3 μm) comprising InGaAsP (compositional wavelength 1.3 μm) and InGaAs were laminated, by MOCVD, on the diffraction grating layer 9 with the diffraction grating formed.
[0037] Then, as shown in FIG. 1D , formation of a ridge 12 that comprises the lower spacer layer 8 , the diffraction grating layer 9 , the p-type InP layer 10 , and the contact layer 11 was carried out by etching up to the etching stop layer 7 leaving a ridge (width 2.8 μm).
[0038] Subsequently, as shown in FIG. 2A , a silicon oxide film 13 (thickness 0.1 μm) was formed on the entire surface upper than the etching stop layer 7 by thermo-chemical vapor deposition (T-CVD). Then, as shown in FIG. 2B , the insulating film (silicon oxide film 13 ) on the contact layer 11 in the upper portion of the ridge 12 was removed. Although the silicon oxide film 13 was employed as the insulating film in Embodiment 1, it is also possible to use a silicon nitride film and the like. As shown in FIG. 2C , a polyimide resin layer 14 was provided on the insulating film 13 on both sides of the ridge 12 , and the wafer surface was flattened. After a p-electrode 15 and an n-electrode 16 were formed on the upper portion of the ridge 12 and on the backside of the n-type InP substrate 1 , respectively, a device having a cavity length of 300 μm was cut out by a cleavage step, and a reflection film having 95% reflectance and a low reflection film having 0.1% reflectance were coated on the rear end face and the front end face thereof, respectively.
[0039] When the semiconductor laser diode shown in FIG. 2C was operated in the operating current range of up to 300 mA at from −5 degree C. to 85 degree C., a lateral single mode was confirmed. In addition, excellent lasing characteristics with a threshold current of 15 to 25 mA and lasing efficiency of 0.3 to 0.4 W/A were shown under the conditions of room temperature and continuous lasing. Further, a threshold current of ca. 35 mA and a lasing efficiency of 0.15 to 0.2 W/A were obtained at an operating temperature of 85 degree C.
[0040] FIG. 3 is a graph showing a comparison result of the operation characteristic of a semiconductor laser diode constructed in almost the same structure as that shown in FIG. 2C except that the upper buffer layer 6 was not provided. In FIG. 3 , the horizontal axis represents operating current, and the vertical axis represents optical power. The solid line 21 shows a characteristic of the semiconductor laser diode provided with the upper buffer layer 6 at an operating temperature of 85 degree C., and the broken line 22 shows a characteristic of the semiconductor laser diode not provided with the upper buffer layer 6 at the same temperature, respectively. When compared at the operating current of 150 mA, the optical power of the semiconductor laser diode provided with the upper buffer layer 6 increased by approximately 20% compared to that of the semiconductor laser diode not provided with the upper buffer layer 6 . At this time, the threshold current was 5 to 10 mA higher in the semiconductor laser diode provided with the upper buffer layer 6 .
[0041] In the above structure, although the lasing wavelength of laser, i.e. the emission wavelength in the multiple-quantum well layer was set to 1.5 μm, a similar effect could also be obtained when the emission wavelength was set to 1.3 μm band. Further, a similar effect was also obtained with a distributed Bragg reflection type and a Fabry-Perot type in place of a distributed feedback type. Furthermore, a laser diode having a similar characteristic could also be obtained even if InGaAlAs series was used instead of InGaAsP series. Still further, the upper buffer layer 6 might be formed of InGaAsP series and InGaAlAs series in place of InP.
[0042] Although it was understood that widening of the ridge width by inserting the upper buffer layer 6 between the upper clad layer 5 and the ridge 12 is effective for power enhancement of a semiconductor laser diode, there is a problem that the threshold current increases as described in BACKGROUND OF THE INVENTION and in the explanation with reference to FIG. 3 . To solve this problem, in Embodiment 1 of the present invention, grooves cut into the upper buffer layer 6 along both side faces of the ridge 12 were provided to suppress diffusion of current flowing into the multiple-quantum well active layer 4 , thereby preventing the increase in the threshold current.
[0043] FIG. 4A is a diagram showing a structure in the fabrication process in which the silicon oxide film 13 was formed on the entire surface upper than the etching stop layer 7 and which is the same as in FIG. 2A and represents the starting point for constructing the semiconductor laser diode of Embodiment 1.
[0044] After forming the silicon oxide film 13 , the silicon oxide film 13 was removed in a dry etching step. At this time, when the silicon oxide film 13 was made thicker at the portion of the contact layer in the upper portion of the ridge 12 , the silicon oxide film 13 was left on the ridge 12 as shown in FIG. 4B , producing a configuration that the ridge 12 covered with the silicon oxide film 13 is on the upper face of the etching stop layer 7 .
[0045] FIG. 4C shows a state that a photoresist 17 was formed on the upper face of the etching stop layer 7 avoiding the ridge 12 .
[0046] FIG. 4D shows a state that the silicon oxide film 13 was subsequently removed in a photo lithography step while leaving the photoresist 17 . As is apparent from the figure, this state represents a state in which the ridge 12 was on the etching stop layer 7 and only the photoresist 17 surrounding the ridge 12 was removed in a groove shape.
[0047] FIG. 5A shows a state that the etching stop layer 7 was first removed in a groove shape by a phosphoric acid based solution using the photoresist 17 removed in the groove shape as a mask from the state shown in FIG. 4D , followed by etching the upper buffer layer 6 in the groove shape with a hydrochloric acid based solution. At this time, the depth of the groove can be adjusted by controlling the etching time. In Embodiment 1, a groove having a depth of 0.1 μm was formed with respect to the film thickness of 0.2 μm of the upper buffer layer 6 . Further, since the film thickness of the silicon oxide film 13 was set to 0.1 μm, the width of the groove formed on the buffer layer 6 also became 0.1 μm. The groove could be formed approximately perpendicularly. More specifically, a groove having a width from more than 0 to 200 nm and an angle of 90 degrees±10 degrees from the substrate surface.
[0048] In the embodiment illustrated, the groove was formed up to one half of the thickness of the upper buffer layer 6 , but the groove may be formed through the entire thickness of the upper buffer layer 6 . In this case, there is an effect that a rise in threshold current by providing the upper buffer layer 6 can be prevented, whereas there is a possibility of affecting a pattern of light emitted from the semiconductor laser diode. Accordingly, how deep the groove is made should be considered depending on each case.
[0049] FIG. 5B shows a state that the photoresist 17 was removed. As is apparent from comparison with FIG. 1D , this state is the same as that in FIG. 1D except that grooves are formed in the etching stop layer 7 and the upper buffer layer 6 along the ridge 12 .
[0050] FIG. 5C shows a state that a silicon oxide film 23 (thickness 0.1 μm) was formed on the entire surface upper than the etching stop layer 7 by T-CVD as explained in FIG. 2A . At first glance, this state appears to be the same as the silicon oxide film 13 in FIG. 4A . However, the silicon oxide film 13 in FIG. 4A was provided to form grooves along the ridge 12 and removed after finishing its use, whereas the silicon oxide film 23 was provided to form an insulating layer including the formed grooves.
[0051] In FIG. 5D , the insulating film (silicon oxide film 23 ) on the contact layer 11 in the upper portion of the ridge 12 was removed as explained in FIG. 2B . Although the silicon oxide film 23 was employed here as the insulating film in Embodiment 1, it is also possible to use a silicon nitride film and the like.
[0052] FIG. 6 shows a state that a polyimide resin layer 24 was formed on the upper face of the silicon oxide film 23 to flatten the wafer surface, the p-electrode 15 was formed on the upper portion of the ridge 12 , and the n-electrode 16 was formed on the backside of the n-type InP substrate 1 .
[0053] Then, the device was cut out by a cleavage step, and the reflection film having 95% reflectance and the low reflection film having 0.1% reflectance were coated on the rear end face and the front end face thereof, respectively, to complete a semiconductor laser diode.
[0054] FIG. 7A is not only a graph explaining the characteristic of the semiconductor laser diode of Embodiment 1 shown in FIG. 6 but also a graph showing comparison results of the operation characteristics of a semiconductor laser diode not having the upper buffer layer 6 and semiconductor laser diodes having the upper buffer layer 6 in which grooves reaching one half of the upper buffer layer 6 are present or absent, respectively. As in FIG. 3 , the horizontal axis represents operating current, and the vertical axis represents optical power. The solid line 21 ′ shows the characteristic of the semiconductor laser diode of Embodiment 1 at an operating temperature of 85 degree C., and the broken line 22 shows the characteristic of the semiconductor laser diode not provided with the upper buffer layer 6 at the same temperature, respectively. The thin solid line 21 shows the characteristic of the case shown in FIG. 3 where the grooves were not provided on the upper buffer layer 6 . As is apparent from comparison of the solid line 21 and the broken line 22 , their threshold currents are comparable, according to Embodiment 1, and an increase in threshold current caused by provision of the upper buffer layer could be suppressed. Further, as is apparent from comparison of the solid line 21 ′ and the solid line 21 , optical power could also be enhanced.
[0055] FIG. 7B is a characteristic graph showing evaluated relation of groove width in the upper buffer layer 6 and cut-off width, where the groove width is shown on the horizontal axis and the cut-off width is shown on the vertical axis. As mentioned earlier, a high power semiconductor laser diode can be realized by widening the ridge width. On the other hand, the widening of the ridge width becomes disadvantageous to the single mode condition. In the present invention, the upper buffer layer 6 was provided and the grooves to prevent current diffusion in the upper buffer layer 6 were provided as shown in Embodiment 1, thereby realizing effective widening of the ridge width. The result of evaluation of the relation between the groove width and the cut-off width under the condition satisfying the single mode is shown in FIG. 7B . Although a cut-off width (ridge width) of 2.8 μm could be realized at a groove width of 0.1 μm as described above, a cut-off width (ridge width) of 2.8 μm could be realized even at a groove width of 0.2 μm. However, it was found that when the groove width became 0.2 μm or wider, the cut-off width became smaller. In addition, a study result obtained when the insulating layer was formed by regrowth as disclosed in JP-A No. 214372/2004 mentioned above is also depicted. When InP, InGaAsP or InGaAlAs was regrown, due to an anisotropy of the crystal growth rate, the groove angle became 126 degrees or more. Thus, the groove width of 0.1 μm could not be formed and the single mode could not be satisfied at a large cut-off width as obtained in the present invention.
[0056] When the semiconductor laser diode of Embodiment 1 was operated in the range up to the operating current of 300 mA at from −5 degree C. to 85 degree C., the operation characteristic shown in FIG. 7A was obtained, and a lateral single mode was confirmed. In addition, it was found from the result in FIG. 7B that the groove width is desirable to be equal to or smaller than 0.8 μm in consideration of fabrication error and the like.
[0057] When the far field pattern was evaluated, expansion of the far field pattern in the semiconductor laser diode having the upper buffer layer 6 but not having the grooves formed along the side faces of the ridge 12 was 45 degrees in the perpendicular direction and 20 degrees in the horizontal direction with respect to the substrate 1 . On the other hand, in the semiconductor laser diode of Embodiment 1, the expansion of the far field pattern was 45 degrees in the perpendicular direction and 25 degrees in the horizontal direction with respect to the substrate 1 , and the anisotropy in the expansion was confirmed to be lessened.
[0058] Further, the semiconductor laser diode of Embodiment 1 exhibited excellent lasing characteristics with a threshold current of 10 to 20 mA and lasing efficiency of 0.3 to 0.4 W/A under the conditions of room temperature and continuous lasing. At an operating temperature of 85 degree C., a threshold current of ca. 20 to 30 mA and a lasing efficiency of 0.15 to 0.2 W/A were obtained. At a temperature of 85 degree C., a threshold current approximately equal to that for the semiconductor laser diode having no upper buffer layer, and an operating current of 150 mA, the optical power was increased by approximately 20% to 40%.
[0059] Although the lasing wavelength of laser, i.e. the emission wavelength of the multiple-quantum well active layer, was set to 1.5 μm in Embodiment 1, similar effects could also be obtained when the wavelength was set to 1.3 μm band or when a distributed Bragg reflection type or a Fabry-Perot type was used in place of the distributed feedback type. It is needless to say that similar effects were obtained as long as grooves having a similar angle could be formed even when the fabrication method of grooves differed. In addition, InGaAlAs series may be used in place of InGaAsP series. Although the silicon oxide film was used as the insulating film, it is also possible to use a silicon nitride film and the like.
[0060] In Embodiment 1, there are advantages that fabrication of a diffraction grating to select an appropriate lasing wavelength in accord with the wavelength corresponding to the absorption-edge energy of the optical modulator region becomes possible by fabricating the diffraction grating on the upper clad layer and that keeping constant the difference (ΔH) between the wavelength of lasing light of the distributed feedback type semiconductor laser diode and the wavelength corresponding to the absorption-edge energy of the optical modulator region becomes possible.
Embodiment 2
[0061] A semiconductor laser diode applied with the present invention can also be realized by a structure starting with an n-type GaAs semiconductor substrate in place of the structure starting with the n-type InP semiconductor substrate. FIGS. 8A to 8 C are diagrams showing as Embodiment 2 the semiconductor laser diode realized by the structure starting with the n-type GaAs semiconductor substrate.
[0062] The semiconductor laser diode shown in Embodiment 2 is different in materials and part of the manufacturing process because the starting substrate is different but can be constructed by steps similar to those in Embodiment 1, and therefore explained in a simplified manner.
[0063] As shown in FIG. 8A , on an n-type GaAs semiconductor substrate 31 (thickness 2 mm), an n-type GaAs buffer layer 32 (film thickness 0.5 μm), a lower clad layer 33 (film thickness 2.5 μm) formed of n-type (Al x Ga 1-x ) 0.5 In 0.5 P (x=0.60), a multiple-quantum well active layer 34 (thickness 0.024 μm) in. which a well layer formed of GaInP (thickness 6 nm) having 1.1% compressive strain and a barrier layer (thickness 6 nm) formed of (Al x Ga 1-x ) 0.5 In 0.5 P (x=0.45) having 0.7% tensile strain were laminated by 2 cycles, an upper clad layer 35 . (film thickness 0.02 μm) formed of p-type (Al x Ga 1-x ) 0.5 In 0.5 P (x=0.50), an upper buffer layer 36 (film thickness 0.3 μm) formed of (Al x Ga 1-x ) 0.5 In 0.5 P, a layer 40 (film thickness 2.0 μm) formed of (Al x Ga 1-x ) 0.5 In 0.5 P (x=0.60), and a contact layer 41 (film thickness 0.2 μm) formed of GaAs were laminated by MOCVD. In this embodiment, the emission wavelength of the multiple-quantum well active layer was about 0.66 μm.
[0064] Then, in dry etching step, etching was performed until the surface of the upper buffer layer 36 was exposed as shown in FIG. 8B to form a ridge 42 . The width of the ridge 42 was 1.7 μm.
[0065] After going through the steps similar to those in FIGS. 4A to 4 D and FIGS. 5A to 5 D, the semiconductor laser diode shown in FIG. 8C could be realized by the process starting with the n-type GaAs semiconductor substrate. Here, the reference numeral 43 denotes a silicon oxide film and represents an insulating layer corresponding to the silicon oxide film 23 in Embodiment 1. The reference numeral 44 represents a polyimide resin, which was provided on the upper face of the silicon oxide film 43 to flatten the wafer surface. This corresponds to the polyimide resin 24 in Embodiment 1. The reference numerals 45 and 46 represent p- and n-electrodes, respectively, which correspond to the p- and n-electrodes 15 and 16 in Embodiment 1. The device was cut out by a cleavage step, and a reflection film having 92% reflectance and a low reflection film having 7% reflectance were coated on the rear end face and the front end face thereof, respectively. The semiconductor laser diode of Embodiment 2 serves as a Fabry-Perot type laser, and therefore it is not necessary to form a diffraction grating layer in the ridge 42 .
[0066] When grooves are formed by etching along the ridge 42 , it is possible to adjust the groove depth by controlling the etching time in Embodiment 2 as well. In Embodiment 2, grooves with a width of 0.1 μm and a depth of 0.1 μm were formed with respect to the film thickness of 0.3 μm of the upper buffer layer 36 . The grooves having an approximately vertical angle could be formed.
[0067] When the semiconductor laser diode of Embodiment 2 was operated in the range up to the operating current of 450 mA at from −10 degree C. to 80 degree C., a lateral single mode was confirmed. Even when grooves were formed as described above, it was confirmed that ridge width could be widened. Further, the semiconductor laser diode of Embodiment 2 exhibited excellent lasing characteristics with a threshold current of 40 to 55 mA and lasing efficiency of 1.0 to 1.2 W/A under the conditions of room temperature and continuous lasing. At a threshold current approximately equal to that for the semiconductor laser diode having no upper buffer layer and an operating current of 400 mA, the optical power was increased by about 20% to 40%.
[0068] Although the lasing wavelength of the semiconductor laser diode, i.e. the emission wavelength of the multiple-quantum well active layer, was set to 0.66 μm in Embodiment 2, similar effects could be obtained even when set to other wavelengths. The semiconductor laser diode fabricated as described above can be applied to laser diode (LD) for digital versatile disc (DVD).
Embodiment 3
[0069] An example of the integrated semiconductor optical waveguide device to which the present invention was applied is explained in Embodiment 3 with reference to FIGS. 9A to 9 E, FIGS. 10A to 10 E, and FIG. 11 . It should be noted that the figure is used strictly for the purpose of explaining the present embodiment and the figure size and the scale described in the present embodiment do not necessarily correspond proportionately.
[0070] As shown in FIG. 9A , on an n-type InP semiconductor substrate 51 (thickness 2 mm), an n-type InP buffer layer 52 (film thickness 0.5 μm), a lower clad layer of electroabsorption type optical modulator 53 (film thickness 0.1 μm) formed of n-type InGaAlAs (compositional wavelength 0.92 μm), a multiple-quantum well active layer 54 in which a well layer (film thickness 7 nm, compositional wavelength 1.5 μm) formed of InGaAlAs having 0.6% compressive strain and a barrier layer (film thickness 10 nm, compositional wavelength 1.35 μm) formed of InGaAlAs having 0.6% tensile strain were laminated by 9 cycles, and an upper clad layer of electroabsorption type optical modulator 55 (film thickness 0.1 μm) formed of InGaAlAs (compositional wavelength 0.92 μm) were laminated.
[0071] As shown in FIG. 9B , etching was performed up to the surface of the n-type InP buffer layer 52 leaving the width (for example, 300 μm) corresponding to an electroabsorption type optical modulator.
[0072] As shown in FIG. 9C , a waveguide lower clad layer 56 (film thickness 0.1 μm) formed of n-type InGaAsP (compositional wavelength 1.10 μm), a waveguide core 57 (film thickness 0.16 μm) formed of InGaAsP (compositional wavelength 1.3 μm), and a waveguide upper clad layer 58 (film thickness 0.1 μm) formed of InGaAsP (compositional wavelength 1.15 μm) were laminated.
[0073] As shown in FIG. 9D , etching was performed up to the surface of the n-type InP buffer layer 52 leaving the electroabsorption type optical modulator in a length of 300 μm and a waveguide in a length of 15001.
[0074] As shown in FIG. 9E , a lower clad layer, 59 (thickness 0.13 μm) formed of n-type InGaAsP (compositional wavelength 1.10 μm), a multiple-quantum well active layer 60 in which a well layer formed of InGaAsP (film thickness 7 nm, compositional wavelength 1.5 μm) having 1.0% compressive strain and a barrier layer formed of InGaAsP (film thickness 12 nm, compositional wavelength 1.3 μm) having 0.5% tensile strain were laminated by 5 cycles, an upper clad layer 61 (film thickness 0.10 μm) formed of InGaAsP (compositional wavelength 1.10 μm), an upper buffer layer 62 (film thickness 0.2 μm) formed of p-type InP, an etching stop layer 63 (film thickness 0.005 μm) formed of InGaAsP (compositional wavelength 1.3 μm), a lower spacer layer 64 (film thickness 0.02 μm) formed of p-type InP, and a diffraction grating layer 65 (film thickness 0.03 μm) formed of InGaAsP (compositional wavelength 1.3 μm) were laminated. The emission wavelength of the multiple-quantum well active layer was about 1.5 μm.
[0075] As shown in FIG. 10A , a diffraction grating was formed on the diffraction grating layer 65 by a known interference exposure method and subsequent etching using a phosphoric acid based solution. Further, a window 66 was formed on the electroabsorption type optical modulator. This diffraction grating serves as a floating type diffraction grating because the lower spacer layer 64 formed of InP is provided between the etching stop layer 63 and the diffraction grating layer 65 . Accordingly, the diffraction grating could be accurately fabricated even when etching time varied somewhat.
[0076] Subsequently, as shown in FIG. 10B , a p-type InP layer 67 (film thickness 2.0 μm) and a contact layer 68 (film thickness 0.3 μm) formed of InGaAsP (compositional wavelength 1.3 μm) and InGaAs were laminated, by MOCVD, on the diffraction grating layer 65 with a diffraction grating formed, the upper clad layer 58 , and the n-type InP buffer layer 52 with the window 66 formed. Since the p-type InP layer 67 with the film thickness of 2.0 μm was exceptionally thicker compared to other layers, the laminated surface was practically flattened.
[0077] As shown in FIG. 10C , etching was performed up to the upper clad layer of the electroabsorption type optical modulator 55 , the waveguide upper clad layer 58 , and the etching stop layer 63 of the laser diode to form a ridge 69 . At this time, the ridge width of the laser diode was 2.5 μm, and the ridge width of the electroabsorption type optical modulator was 1.5 μm. The ridge width of the waveguide that connects the laser diode portion to the electroabsorption type optical modulator portion was tapered so as to continuously change from the former toward the latter.
[0078] As shown in FIG. 10D , the contact layer 68 of the waveguide was removed to separate the contact layer of the laser diode and that of the electroabsorption type optical modulator.
[0079] FIG. 11 is a diagram showing the completed state of the integrated optical waveguide device of Embodiment 3. This could be obtained by implementing the following steps after the structure shown in FIG. 10D . As explained in FIG. 5C , a silicon dioxide film 70 (thickness 0.1 μm) was formed, by T-CVD, on the entire surfaces upper than the upper clad layer of the electroabsorption type optical modulator 55 , the waveguide upper clad layer 58 , and the etching stop layer 63 of the laser diode. Then, as explained in FIG. 5C , the insulating film on the contact layer 68 in the upper portion of the ridge 69 of the semiconductor laser diode and the electroabsorption type optical modulator was removed (at this time, the silicon dioxide film 70 remained on the upper portion of the waveguide). Although, in Embodiment 3, the silicon dioxide film was used as the insulating film, it is also possible to use silicon nitride film and the like. Next, as explained in FIG. 6 , the wafer surface was flattened with a polyimide resin 71 . Finally, a p-electrode 72 was formed on the contact layer 68 of the semiconductor laser diode, a p-electrode 73 was formed on the contact layer 68 of the electroabsorption type optical modulator, and an n-electrode 74 was formed on the backside of the n-type InP substrate 51 . Then, the device was cut out by a cleavage step, and a reflection film having 95% reflectance and a low reflection film having 0.1% reflectance were coated on the rear end face and the front end face thereof, respectively.
[0080] In Embodiment 3, since the diffraction grating 65 is formed over the etching stop layer 63 in contrast to forming the diffraction grating in the upper clad layer 61 or the upper buffer layer 62 , integration is possible by four growth steps. It should be noted that the growth order of the electroabsorption type optical modulator, the waveguide, and the semiconductor laser diode is not limited to this. Further, as the material for the semiconductor laser diode, InGaAlAs series can be employed in place of InGaAsP series as explained in Embodiment 2. Furthermore, as the material for the electroabsorption type optical modulator, InGaAsP series may be used in place of InGaAlAs series.
[0081] In Embodiment 3, the ridge width in the region of the semiconductor laser diode was 2.0 μm, and the ridge width in the region of the electroabsorption type optical modulator was 1.4 μm. The waveguide connecting the both regions was 150 μm in length and tapered. As the result, the ridge of the semiconductor laser diode and the ridge of the electroabsorption type optical modulator could be coupled with little optical loss.
[0082] FIG. 12 is a graph showing evaluation results of characteristics when the ridge widths of the semiconductor laser diode were 2.0 μm and 2.5 μm, respectively, and the ridge width of the electroabsorption type optical modulator was 1.4 μm, where the waveguide length was taken on the horizontal axis and the transmittance was taken on the vertical axis. As is evident from the figure, practically the same characteristics were obtained in the range of the waveguide length of 10 μm to 150 μm. Therefore, as long as both are coupled with an appropriate difference in width and length, the tapering inclination has little influence on the coupling. Further, provision of the window 66 facilitates optical coupling to optical fiber, thereby enabling coupling loss to be suppressed to 3 dB or lower.
[0083] Further, when the far field pattern of the integrated semiconductor optical waveguide device of Embodiment 3 was measured, the expansion was 45 degrees in the perpendicular direction and 35 degrees in the horizontal direction with respect to the substrate in the integrated semiconductor optical waveguide device described in Embodiment 3, whereas the expansion was 45 degrees in the perpendicular direction and 20 degrees in the horizontal direction in the semiconductor laser diode alone. Thus it was confirmed that anisotropy in expansion was lessened in the former. The operating current of the semiconductor laser diode was in the range of 70 to 150 mA when operated at from −5 degree C. to 85 degree C. By controlling the offset bias optimally and making modulation amplitude voltage equal to or lower than 2.5 V at from −5 degree C. to 85 degree C. with respect to the voltage applied to the p-electrode 73 of the electroabsorption type optical modulator, an optical power equal to or higher than 1 dB, a dynamic quenching ratio equal to or higher than 10 dB, and a band equal to or higher than 10 Gbps could be obtained. Owing to this, it became possible to obtain a good eye pattern at a bit rate of 10 Gbps and a transmission distance of 40 km or more without a need for temperature control between −5 degree C. and 85 degree C.
[0084] Although the semiconductor laser diode of the integrated semiconductor optical waveguide device of Embodiment 3 had the same structure as that of the semiconductor laser diode as the premise of the present invention that was explained in FIGS. 1 and 2 , it may be structured so as to have grooves shown in FIG. 6 explained in Embodiment 1.
Embodiment 4—Fabrication Method of Mach-Zehnder (MZ) Version of Integrated Device
[0085] As Embodiment 4 of the integrated semiconductor optical waveguide device applied with the present invention, an example of the integrated semiconductor optical waveguide device in which a Mach-Zehnder type optical modulator was employed in place of the electroabsorption type optical modulator is explained using FIG. 13 . It should be noted that the figure is used only to explain the present embodiment and the figure size and the scale described in the present embodiment do not necessarily correspond proportionately.
[0086] FIG. 13 is a diagram showing the structure of the integrated optical waveguide device of Embodiment 4. In the optical waveguide device of Embodiment 4, a semiconductor laser diode LD, a waveguide WG, a Mach-Zehnder type optical modulator MZ, and a window 66 were formed on an n-type InP substrate 1 and InP buffer layer 2 and were in cascade connection. The semiconductor laser diode LD had the same structure as that of the semiconductor laser diode as the premise of the present invention that was explained with reference to FIGS. 1 and 2 , and the same reference numerals were attached. Although the waveguide WG was the same as that in the structure of the integrated semiconductor optical waveguide device of Embodiment 2 that was explained with reference to FIGS. 9 to 11 , the reference numerals were omitted because the illustration becomes complicated. The Mach-Zehnder type optical modulator MZ was not only connected to the waveguide WG but also split into two optical paths 81 and 82 , which were again joined together to be connected to the window 66 . On one optical path 81 of the two optical paths 81 and 82 , the contact layer 11 was formed. As in the case of the waveguide WG, the waveguide lower clad layer 56 , the waveguide core 57 formed of InGaAsP (compositional wavelength 1.3 μm), and the waveguide upper clad layer 58 formed of InGaAsP (compositional wavelength 1.15 μm) were also laminated for the two optical paths 81 and 82 .
[0087] To describe the fabrication process briefly, first, semiconductor laser diode LD was laminated in a manner similar to that shown in FIG. 1C , and then etching of the regions for the waveguide WG and the Mach-Zehnder type optical modulator MZ was performed up to the surface of the InP buffer layer 2 , followed by laminating the above waveguide parts 56 to 58 thereon. After forming the window 66 , a p-type InP layer and the contact layer 11 were laminated. This state was similar to that shown in FIG. 10B . Then, in a manner similar to that shown in FIGS. 10C and 10D , the structure shown in FIG. 13 was obtained. Finally, in a manner similar to that shown in FIG. 11 , the integrated semiconductor optical waveguide device of Embodiment 4 was completed, though the illustration thereof was omitted.
[0088] Here, optical path lengths of the two optical paths 81 and 82 are made to differ from each other by one half of the wavelength of oscillation frequency of the semiconductor laser diode LD. When the voltage applied between the electrode connected to the contact layer 11 of the optical path 81 and the electrode provided on the backside of the substrate 1 becomes a predetermined value, the respective optical path lengths of the optical paths 81 and 82 are, for example, made to become equal by the change in the refractive index of the optical path 81 and the resulting change in transmitted optical path length. As the result, when there is no voltage between those electrodes, no optical signal is output, and when the voltage is applied between the electrodes, an optical signal is output.
[0089] In Embodiment 4 as well, the ridge of the waveguide WG was tapered, for example with the ridge width of the semiconductor laser diode LD being 2.0 μm and the ridge width of the Mach-Zehnder type optical modulator MZ being 1.0 μm, such that both might be coupled with little optical loss. Further, optical coupling to optical fiber was facilitated by the window 66 , and coupling loss could be suppressed to 3 dB or lower. The operating current of the semiconductor laser diode LD was in the range of 70 to 150 mA when operated at from −5 degree C. to 85 degree C. By controlling the offset bias optimally and making modulation amplitude voltage equal to or lower than 2.5 V at from −5 degree C. to 85 degree C. with respect to the voltage applied to the electrode 11 of the Mach-Zehnder type optical modulator, an optical power equal to or higher than 3 dB, a dynamic quenching ratio equal to or higher than 10 dB, and a band equal to or higher than 10 Gbps could be obtained. Owing to this, it became possible to obtain a good eye pattern at a bit rate of 10 Gbps and a transmission distance of 40 km or more without a need for temperature control between −5 degree C. and 85 degree C.
[0090] It should be noted that the Mach-Zehnder type optical modulator MZ is not limited to this but may be replaced by an optical waveguide device provided with functions comparable to this. Further, integration with an optical amplifier in addition to an optical modulator is also possible.
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A conventional semiconductor laser diode is small in optical power at a constant operating current and limited in ridge width when integrated with an optical device, which forces the integration to be performed by lowering the original characteristic and makes it difficult to reduce cost and power consumption. In a semiconductor laser diode, widening of the ridge width is made possible by lowering the difference in refractive indexes between the ridge and other components, diffusion current and increase in the difference of refractive indexes are prevented by forming approximately vertical grooves along both sides of the ridge, and deterioration in characteristics due to regrowth is prevented by forming a diffraction grating on the ridge. The semiconductor laser diode is integrated with an optical device such as electroabsorption type optical modulator without increase of growth cycles and without restriction of the ridge width by using a tapered waveguide.
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RELATED APPLICATIONS
This application claims benefit of provisional application U.S. Ser. No. 60/955,985, filed Aug. 15, 2007, herein incorporated by reference.
FIELD OF THE INVENTION
The present invention relates 6-substituted sulfonyl-1,3,3-trialkyl-6-azabicyclo[3.2.1]octane compounds useful to inhibit 11β-hydroxysteroid dehydrogenase type-I, pharmaceutical compositions containing the compounds, and methods of treatment, prevention, inhibition, or amelioration of one or more conditions associated with the expression of 11β-hydroxysteroid dehydrogenase type-I using such compounds or pharmaceutical compositions.
BACKGROUND OF THE INVENTION
Glucocorticoids are steroid hormones that regulate many metabolic and homeostatic processes, including fat metabolism, function and distribution. Glucocorticoids also have profound and diverse physiological effects on development, neurobiology, inflammation, blood pressure, metabolism and programmed cell death.
Glucocorticoid action is dependent on the following factors: 1) circulating levels of glucocorticoid; 2) protein binding of glucocorticoids in circulation; 3) intracellular receptor density inside target tissues; and 4) tissue-specific pre-receptor metabolism by glucocorticoid-activating and glucocorticoid-inactivating enzymes collectively known as 11-beta-hydroxysteroid dehydrogenase (11-β-HSD). Two distinct isozymes of 11-β-HSD have been cloned and characterized. These two isozymes, known as 11-β-HSD type I and 11-β-HSD type II, respectively, catalyze the interconversion of active and inactive forms of various glucocorticoids. For example, in humans, the primary endogenously-produced glucocorticoid is cortisol. 11-β-HSD type I and 11-β-HSD type II catalyze the interconversion of hormonally active cortisol and inactive cortisone. 11-β-HSD type I is widely distributed in human tissues and its expression has been detected in lung, testis, central nervous system and most abundantly in liver and adipose tissue. Conversely, 11-β-HSD type II expression is found mainly in kidney, placenta, colon and salivary gland tissue.
Up-regulation of 11-β-HSD type I can lead to elevated cellular glucocorticoid levels and amplified glucocorticoid activity. This, in turn, can lead to increased hepatic glucose production, adipocyte differentiation and insulin resistance. In type II diabetes, insulin resistance is a significant pathogenic factor in the development of hyperglycemia. Persistent or uncontrolled hyperglycemia in both type 1 and type 2 diabetes has been associated with increased incidence of macrovascular and/or microvascular complications including atherosclerosis, coronary heart disease, peripheral vascular disease, stroke, nephropathy, neuropathy and retinopathy. Insulin resistance, even in the absence of profound hyperglycemia, is a component also of metabolic syndrome, which is characterized by elevated blood pressure, high fasting blood glucose levels, abdominal obesity, increased triglyceride levels and/or decreased HDL cholesterol. Further, glucocorticoids are known to inhibit the glucose-stimulated secretion of insulin from pancreatic beta-cells. Inhibition of 11-β-HSD type I is, therefore, expected to be beneficial in the treatment of metabolic syndromes, obesity, obesity-related disorders, hypertension, atherosclerosis, lipid disorders, type-II diabetes, insulin resistance, pancreatitis and associated conditions.
Mild cognitive impairment is a common feature of aging that may be ultimately related to the progression of dementia. Chronic exposure to glucocorticoid excess in certain brain subregions has been proposed to contribute to the decline of cognitive function. Inhibition of 11-β-HSD type I is expected to reduce exposure to glucocorticoids in the brain and protect against deleterious glucocorticoid effects on neuronal function, including cognitive impairment, dementia and/or depression, especially in connection with Alzheimer's Disease.
Glucocorticoids also have a role in corticosteroid-induced glaucoma. This particular pathology is characterized by a significant increase in intra-ocular pressure, which unresolved can lead to partial visual field loss and eventually blindness. Inhibition of 11-β-HSD type I is expected to reduce local glucocorticoid concentrations and, thus, intra-ocular pressure, producing beneficial effects in the management of glaucoma and other visual disorders.
Finally, glucocorticoids can have adverse effects on skeletal tissues. Continued exposure to excess glucocorticoids can produce osteoporosis and increased risk of fractures. Inhibition of 11-β-HSD type I should reduce local glucocorticoid concentration within osteoblasts and osteoclasts, producing beneficial effects for management of bone disease, including osteoporosis.
In view of the foregoing, there is a clear and continuing need for new compounds that target 11-β-HSD type I.
SUMMARY OF THE INVENTION
In its many embodiments, the present invention provides a novel class of heterocyclic compounds as inhibitors of 11β-hydroxysteroid dehydrogenase type-I, pharmaceutical compositions containing the compounds, and methods of treatment, prevention, inhibition, or amelioration of one or more conditions associated with the expression of 11β-hydroxysteroid dehydrogenase type-I using such compounds or pharmaceutical compositions.
In one aspect, the present application discloses a compound, or a pharmaceutically acceptable salt, solvate, ester or prodrug of said compound, said compound having the general structure shown in Formula I:
wherein:
R 1 represents alkyl, cycloalkyl, alkenyl, aryl, arylalkyl, arylalkenyl, heteroaryl or heteroarylalkyl; and R 2 -R 4 independently represent alkyl;
with the exception of those compounds wherein:
R 2 -R 4 each represent methyl; and R 1 represents phenyl substituted by substituted alkoxycarbonyl, substituted alkylcarbonyloxy, substituted sulfonylamino, substituted carbonylamino, or unsubstituted or substituted aminocarbonyl;
and excluding the following compounds:
1,3,3-trimethyl-6-[(phenylmethyl)sulphonyl]-6-azabicyclo[3.2.1]octane; 6-[(3,4-difluorophenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[(4-aminophenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 1,3,3-trimethyl-6-[[4-(5-phenyl-2-oxazolyl)phenyl]sulfonyl]-6-azabicyclo[3.2.1]octane; 6-[(2-methyl-5-tert-butylphenyl)sulfonyl]-6-azabicyclo[3.2.1]octane; 6-[[3-(4,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxyphenyl]sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[[5-2,6-dichloro-4-(4,5-dihydro-3,5-dioxo-1,2,4-triazin-2(3H)-yl)phenoxy]-2-hydroxyphenyl]sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 1,3,3-trimethyl-6-[[5-[2-[[2-(2-oxo-1-imidazolidinyl)ethyl]amino]-4-pyrimidinyl]-2-thienyl]sulfonyl]-6-azabicyclo[3.2.1]octane; 6-[(4-ethoxyphenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 1,3,3-trimethyl-6-[[2-(trifluoromethyl)phenyl]sulfonyl]-6-azabicyclo[3.2.1]octane; 6-[(2,3-dichlorophenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 3-[(1,3,3-trimethyl-6-azabicyclo[3.2.1]oct-6-yl)sulfonyl]benzoic acid; 3-[(1,3,3-trimethyl-6-azabicyclo[3.2.1]oct-6-yl)sulfonyl]benzoic acid methyl ester; 1,3,3-trimethyl-6-[(3-nitrophenyl)sulfonyl]-6-azabicyclo[3.2.1]octane; 4-[(1,3,3-trimethyl-6-azabicyclo[3.2.1]oct-6-yl)sulfonyl]benzoic acid; 1,3,3-trimethyl-6-[(2,3,5,6-tetramethylphenyl)sulfonyl]-6-azabicyclo[3.2.1]octane; 1,3,3-trimethyl-6-[(2-nitrophenyl)sulfonyl]-6-azabicyclo[3.2.1]octane; 6-[(4-acetylphenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[(2,5-dimethylphenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[(4-methoxyphenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[(5-bromo-2-ethoxyphenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[(2,5-dibromophenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[(2,4-difluorophenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[(5-bromo-6-chloro-3-pyridinyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 6-[(2,5-dichlorophenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; 1,3,3-trimethyl-6-phenylsulfonyl-6-azabicyclo[3.2.1]octane; 6-(1,3,3-trimethyl-6-azabicyclo[3.2.1]octan-6-ylsulfonyl)benzo[d]oxazol-2(3H)-one; 6-(1,3,3-trimethyl-6-azabicyclo[3.2.1]octan-6-ylsulfonyl)benzo[cd]indol-2(1H)-one; 3-((1R,5S)-1,3,3-trimethyl-6-azabicyclo[3.2.1]octan-6-ylsulfonyl)-1H-pyrazolo[3,4-b]pyridine; 2,2,2-trifluoro-1-(8-(1,3,3-trimethyl-6-azabicyclo[3.2.1]octan-6-ylsulfonyl)-3,4-dihydroisoquinolin-2(1H)-yl)ethanone; 6-[(4-tert-butylphenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane; and 6-[(3-aminophenyl)sulfonyl]-1,3,3-trimethyl-6-azabicyclo[3.2.1]octane.
The compounds of Formula I, including those excepted and excluded, as well as salts, solvates, esters and prodrugs thereof, are inhibitors of 11β-hydroxysteroid dehydrogenase type-I, and can be used in the treatment of metabolic syndromes, obesity, obesity-related disorders, hypertension, atherosclerosis, lipid disorders, type-II diabetes, insulin resistance, pancreatitis and associated conditions.
Alternatively, the present invention provides for a method for treating a metabolic syndrome in a patient in need thereof which comprises administering to said patient a therapeutically effective amount of at least one compound of the Formula I:
or a pharmaceutically acceptable salt, solvate, ester or prodrug thereof;
wherein:
R 1 represents alkyl, cycloalkyl, alkenyl, aryl, arylalkyl, arylalkenyl, heteroaryl or heteroarylalkyl; and R 2 -R 4 independently represent alkyl.
A further embodiment of the present invention is a method for treating obesity or an obesity-related disorder in a patient in need thereof which comprises administering to said patient a therapeutically effective amount of at least one compound of the Formula I:
or a pharmaceutically acceptable salt, solvate, ester or prodrug thereof;
wherein:
R 1 represents alkyl, cycloalkyl, alkenyl, aryl, arylalkyl, arylalkenyl, heteroaryl or heteroarylalkyl; and R 2 -R 4 independently represent alkyl.
Another embodiment of the present invention is a method for treating type-II diabetes in a patient in need thereof which comprises administering to said patient a therapeutically effective amount of at least one compound of the Formula I:
or a pharmaceutically acceptable salt, solvate, ester or prodrug thereof;
wherein:
R 1 represents alkyl, cycloalkyl, alkenyl, aryl, arylalkyl, arylalkenyl, heteroaryl or heteroarylalkyl; and R 2 -R 4 independently represent alkyl.
Another embodiment of the present invention is a method for treating atherosclerosis in a patient in need thereof which comprises administering to said patient a therapeutically effective amount of at least one compound of the Formula I:
or a pharmaceutically acceptable salt, solvate, ester or prodrug thereof;
wherein:
R 1 represents alkyl, cycloalkyl, alkenyl, aryl, arylalkyl, arylalkenyl, heteroaryl or heteroarylalkyl; and R 2 -R 4 independently represent alkyl.
DETAILED DESCRIPTION
In one embodiment, the present invention discloses certain heterocyclic compounds which are represented by structural Formula I, or a pharmaceutically acceptable salt, solvate, ester or prodrug thereof, wherein the various moieties are as described above.
In another embodiment, the present invention embodies compounds of the Formula I, as well as salts, solvates, esters and prodrugs thereof, wherein:
R 1 represents phenyl, naphthyl, benzyl, stryryl, furanyl, thienyl, pyrazolyl, pyridyl, oxazolyl, benzothienyl or benzooxadiazolyl, each of which is optionally substituted by one or more substituents selected from the group consisting of alkyl, halogen, alkoxy, alkylcarbonyl, alkylsulphonyl, cyano, nitro, aryl, heteroaryl, aryloxy, carboxyl, alkoxycarbonylalkyl, cycloalkyl and morpholino; and R 2 -R 4 each represent alkyl.
Table 1 shows structures of representative compounds of this invention. The table and the compounds therein are not intended, nor should they be construed, to limit this invention in any manner whatsoever.
TABLE 1
COMPOUND NO.
STRUCTURE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
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
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
As used above, and throughout this disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings:
“Patient” includes both human and animals.
“Mammal” means humans and other mammalian animals.
“Alkyl” means an aliphatic hydrocarbon group which may be straight or branched and comprising about 1 to about 20 carbon atoms in the chain. Preferred alkyl groups contain about 1 to about 12 carbon atoms in the chain. More preferred alkyl groups contain about 1 to about 6 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl or propyl, are attached to a linear alkyl chain. “Lower alkyl” means a group having about 1 to about 6 carbon atoms in the chain which may be straight or branched. “Alkyl” may be unsubstituted or optionally substituted by one or more substituents which may be the same or different, each substituent being independently selected from the group consisting of halo, alkyl, aryl, cycloalkyl, cyano, hydroxy, alkoxy, alkylthio, amino, oxime (e.g., ═N—OH), —NH(alkyl), —NH(cycloalkyl), —N(alkyl) 2 , —O—C(O)-alkyl, —O—C(O)-aryl, —O—C(O)-cycloalkyl, carboxy and —C(O)O-alkyl. Non-limiting examples of suitable alkyl groups include methyl, ethyl, n-propyl, isopropyl and t-butyl.
“Alkenyl” means an aliphatic hydrocarbon group containing at least one carbon-carbon double bond and which may be straight or branched and comprising about 2 to about 15 carbon atoms in the chain. Preferred alkenyl groups have about 2 to about 12 carbon atoms in the chain; and more preferably about 2 to about 6 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl or propyl, are attached to a linear alkenyl chain. “Lower alkenyl” means about 2 to about 6 carbon atoms in the chain which may be straight or branched. “Alkenyl” may be unsubstituted or optionally substituted by one or more substituents which may be the same or different, each substituent being independently selected from the group consisting of halo, alkyl. aryl, cycloalkyl, cyano, alkoxy and —S(alkyl). Non-limiting examples of suitable alkenyl groups include ethenyl, propenyl, n-butenyl, 3-methylbut-2-enyl, n-pentenyl, octenyl and decenyl.
“Alkylene” means a difunctional group obtained by removal of a hydrogen atom from an alkyl group that is defined above. Non-limiting examples of alkylene include methylene, ethylene and propylene.
“Alkynyl” means an aliphatic hydrocarbon group containing at least one carbon-carbon triple bond and which may be straight or branched and comprising about 2 to about 15 carbon atoms in the chain. Preferred alkynyl groups have about 2 to about 12 carbon atoms in the chain; and more preferably about 2 to about 4 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl or propyl, are attached to a linear alkynyl chain. “Lower alkynyl” means about 2 to about 6 carbon atoms in the chain which may be straight or branched. Non-limiting examples of suitable alkynyl groups include ethynyl, propynyl, 2-butynyl and 3-methylbutynyl. “Alkynyl” may be unsubstituted or optionally substituted by one or more substituents which may be the same or different, each substituent being independently selected from the group consisting of alkyl, aryl and cycloalkyl.
“Aryl” means an aromatic monocyclic or multicyclic ring system comprising about 6 to about 14 carbon atoms, preferably about 6 to about 10 carbon atoms. The aryl group can be optionally substituted with one or more “ring system substituents” which may be the same or different, and are as defined herein. Non-limiting examples of suitable aryl groups include phenyl and naphthyl.
“Heteroaryl” means an aromatic monocyclic or multicyclic ring system comprising about 5 to about 14 ring atoms, preferably about 5 to about 10 ring atoms, in which one or more of the ring atoms is an element other than carbon, for example nitrogen, oxygen or sulfur, alone or in combination. Preferred heteroaryls contain about 5 to about 6 ring atoms. The “heteroaryl” can be optionally substituted by one or more “ring system substituents” which may be the same or different, and are as defined herein. The prefix aza, oxa or thia before the heteroaryl root name means that at least a nitrogen, oxygen or sulfur atom respectively, is present as a ring atom. A nitrogen atom of a heteroaryl can be optionally oxidized to the corresponding N-oxide. “Heteroaryl” may also include a heteroaryl as defined above fused to an aryl as defined above. Non-limiting examples of suitable heteroaryls include pyridyl, pyrazinyl, furanyl, thienyl, pyrimidinyl, pyridone (including N-substituted pyridones), isoxazolyl, isothiazolyl, oxazolyl, thiazolyl, pyrazolyl, furazanyl, pyrrolyl, pyrazolyl, triazolyl, 1,2,4-thiadiazolyl, pyrazinyl, pyridazinyl, quinoxalinyl, phthalazinyl, oxindolyl, imidazo[1,2-a]pyridinyl, imidazo[2,1-b]thiazolyl, benzofurazanyl, indolyl, azaindolyl, benzimidazolyl, benzothienyl, quinolinyl, imidazolyl, thienopyridyl, quinazolinyl, thienopyrimidyl, pyrrolopyridyl, imidazopyridyl, isoquinolinyl, benzoazaindolyl, 1,2,4-triazinyl, benzothiazolyl and the like. The term “heteroaryl” also refers to partially saturated heteroaryl moieties such as, for example, tetrahydroisoquinolyl, tetrahydroquinolyl and the like.
“Aralkyl” or “arylalkyl” means an aryl-alkyl-group in which the aryl and alkyl are as previously described. Preferred aralkyls comprise a lower alkyl group. Non-limiting examples of suitable aralkyl groups include benzyl, 2-phenethyl and naphthalenylmethyl. The bond to the parent moiety is through the alkyl.
“Alkylaryl” means an alkyl-aryl-group in which the alkyl and aryl are as previously described. Preferred alkylaryls comprise a lower alkyl group. Non-limiting example of a suitable alkylaryl group is tolyl. The bond to the parent moiety is through the aryl.
“Cycloalkyl” means a non-aromatic mono- or multicyclic ring system comprising about 3 to about 10 carbon atoms, preferably about 5 to about 10 carbon atoms. Preferred cycloalkyl rings contain about 5 to about 7 ring atoms. The cycloalkyl can be optionally substituted with one or more “ring system substituents” which may be the same or different, and are as defined above. Non-limiting examples of suitable monocyclic cycloalkyls include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl and the like. Non-limiting examples of suitable multicyclic cycloalkyls include 1-decalinyl, norbornyl, adamantyl and the like.
“Cycloalkylalkyl” means a cycloalkyl moiety as defined above linked via an alkyl moiety (defined above) to a parent core. Non-limiting examples of suitable cycloalkylalkyls include cyclohexylmethyl, adamantylmethyl and the like.
“Cycloalkenyl” means a non-aromatic mono or multicyclic ring system comprising about 3 to about 10 carbon atoms, preferably about 5 to about 10 carbon atoms which contains at least one carbon-carbon double bond. Preferred cycloalkenyl rings contain about 5 to about 7 ring atoms. The cycloalkenyl can be optionally substituted with one or more “ring system substituents” which may be the same or different, and are as defined above. Non-limiting examples of suitable monocyclic cycloalkenyls include cyclopentenyl, cyclohexenyl, cyclohepta-1,3-dienyl, and the like. Non-limiting example of a suitable multicyclic cycloalkenyl is norbornylenyl.
“Cycloalkenylalkyl” means a cycloalkenyl moiety as defined above linked via an alkyl moiety (defined above) to a parent core. Non-limiting examples of suitable cycloalkenylalkyls include cyclopentenylmethyl, cyclohexenylmethyl and the like.
“Halogen” means fluorine, chlorine, bromine, or iodine. Preferred are fluorine, chlorine and bromine.
“Ring system substituent” means a substituent attached to an aromatic or non-aromatic ring system which, for example, replaces an available hydrogen on the ring system. Ring system substituents may be the same or different, each being independently selected from the group consisting of alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, alkylaryl, heteroaralkyl, heteroarylalkenyl, heteroarylalkynyl, alkylheteroaryl, hydroxy, hydroxyalkyl, alkoxy, alkoxyalkyl, aryloxy, aralkoxy, acyl, aroyl, halo, nitro, cyano, carboxy, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkylsulfonyl, arylsulfonyl, heteroarylsulfonyl, alkylthio, arylthio, heteroarylthio, aralkylthio, heteroaralkylthio, cycloalkyl, heterocyclyl, —O—C(O)-alkyl, —O—C(O)-aryl, —O—C(O)-cycloalkyl, oxo, —C(═N—CN)—NH 2 , —C(═NH)—NH 2 , —C(═NH)—NH(alkyl), oxime (e.g., ═N—OH), Y 1 Y 2 N—, Y 1 Y 2 N-alkyl-, Y 1 Y 2 NC(O)—, Y 1 Y 2 NSO 2 − and —SO 2 NY 1 Y 2 , wherein Y 1 and V 2 can be the same or different and are independently selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, and aralkyl. “Ring system substituent” may also mean a single moiety which simultaneously replaces two available hydrogens on two adjacent carbon atoms (one H on each carbon) on a ring system. Examples of such moiety are methylene dioxy, ethylenedioxy, —C(CH 3 ) 2 — and the like which form moieties such as, for example:
In a preferred embodiment, R 1 represents a phenyl group optionally substituted with one or more ring substituents. In one especially preferred embodiment, a ring substituent is bonded at the para-position of the phenyl ring. In another especially preferred embodiment, the ring substituent is a branched alkyl group. In another especially preferred embodiment, the ring substituent contains a hydroxyl group or an ether linkage.
“Heteroarylalkyl” means a heteroaryl moiety as defined above linked via an alkyl moiety (defined above) to a parent core. Non-limiting examples of suitable heteroaryls include 2-pyridinylmethyl, quinolinylmethyl and the like.
“Heterocyclyl” means a non-aromatic saturated monocyclic or multicyclic ring system comprising about 3 to about 10 ring atoms, preferably about 5 to about 10 ring atoms, in which one or more of the atoms in the ring system is an element other than carbon, for example nitrogen, oxygen or sulfur, alone or in combination. There are no adjacent oxygen and/or sulfur atoms present in the ring system. Preferred heterocyclyls contain about 5 to about 6 ring atoms. The prefix aza, oxa or thia before the heterocyclyl root name means that at least a nitrogen, oxygen or sulfur atom respectively is present as a ring atom. Any —NH in a heterocyclyl ring may exist protected such as, for example, as an —N(Boc), —N(CBz), —N(Tos) group and the like; such protections are also considered part of this invention. The heterocyclyl can be optionally substituted by one or more “ring system substituents” which may be the same or different, and are as defined herein. The nitrogen or sulfur atom of the heterocyclyl can be optionally oxidized to the corresponding N-oxide, S-oxide or S,S-dioxide. Non-limiting examples of suitable monocyclic heterocyclyl rings include piperidyl, pyrrolidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, 1,4-dioxanyl, tetrahydrofuranyl, tetrahydrothiophenyl, lactam, lactone, and the like. “Heterocyclyl” may also mean a single moiety (e.g., carbonyl) which simultaneously replaces two available hydrogens on the same carbon atom on a ring system. Example of such moiety is pyrrolidone:
“Heterocyclylalkyl” means a heterocyclyl moiety as defined above linked via an alkyl moiety (defined above) to a parent core. Non-limiting examples of suitable heterocyclylalkyls include piperidinylmethyl, piperazinylmethyl and the like.
“Heterocyclenyl” means a non-aromatic monocyclic or multicyclic ring system comprising about 3 to about 10 ring atoms, preferably about 5 to about 10 ring atoms, in which one or more of the atoms in the ring system is an element other than carbon, for example nitrogen, oxygen or sulfur atom, alone or in combination, and which contains at least one carbon-carbon double bond or carbon-nitrogen double bond. There are no adjacent oxygen and/or sulfur atoms present in the ring system. Preferred heterocyclenyl rings contain about 5 to about 6 ring atoms. The prefix aza, oxa or thia before the heterocyclenyl root name means that at least a nitrogen, oxygen or sulfur atom respectively is present as a ring atom. The heterocyclenyl can be optionally substituted by one or more ring system substituents, wherein “ring system substituent” is as defined above. The nitrogen or sulfur atom of the heterocyclenyl can be optionally oxidized to the corresponding N-oxide, S-oxide or S,S-dioxide. Non-limiting examples of suitable heterocyclenyl groups include 1,2,3,4-tetrahydropyridinyl, 1,2-dihydropyridinyl, 1,4-dihydropyridinyl, 1,2,3,6-tetrahydropyridinyl, 1,4,5,6-tetrahydropyrimidinyl, 2-pyrrolinyl, 3-pyrrolinyl, 2-imidazolinyl, 2-pyrazolinyl, dihydroimidazolyl, dihydrooxazolyl, dihydrooxadiazolyl, dihydrothiazolyl, 3,4-dihydro-2H-pyranyl, dihydrofuranyl, fluorodihydrofuranyl, 7-oxabicyclo[2.2.1]heptenyl, dihydrothiophenyl, dihydrothiopyranyl, and the like. “Heterocyclenyl” may also mean a single moiety (e.g., carbonyl) which simultaneously replaces two available hydrogens on the same carbon atom on a ring system. Example of such moiety is pyrrolidinone:
“Heterocyclenylalkyl” means a heterocyclenyl moiety as defined above linked via an alkyl moiety (defined above) to a parent core.
It should be noted that in hetero-atom containing ring systems of this invention, there are no hydroxyl groups on carbon atoms adjacent to a N, O or S, as well as there are no N or S groups on carbon adjacent to another heteroatom. Thus, for example, in the ring:
there is no —OH attached directly to carbons marked 2 and 5.
It should also be noted that tautomeric forms such as, for example, the moieties:
are considered equivalent in certain embodiments of this invention.
“Alkynylalkyl” means an alkynyl-alkyl-group in which the alkynyl and alkyl are as previously described. Preferred alkynylalkyls contain a lower alkynyl and a lower alkyl group. The bond to the parent moiety is through the alkyl. Non-limiting examples of suitable alkynylalkyl groups include propargylmethyl.
“Heteroaralkyl” means a heteroaryl-alkyl-group in which the heteroaryl and alkyl are as previously described. Preferred heteroaralkyls contain a lower alkyl group. Non-limiting examples of suitable aralkyl groups include pyridylmethyl, and quinolin-3-ylmethyl. The bond to the parent moiety is through the alkyl.
“Hydroxyalkyl” means a HO-alkyl-group in which alkyl is as previously defined. Preferred hydroxyalkyls contain lower alkyl. Non-limiting examples of suitable hydroxyalkyl groups include hydroxymethyl and 2-hydroxyethyl.
“Acyl” means an H—C(O)—, alkyl-C(O)— or cycloalkyl-C(O)—, group in which the various groups are as previously described. The bond to the parent moiety is through the carbonyl. Preferred acyls contain a lower alkyl. Non-limiting examples of suitable acyl groups include formyl, acetyl and propanoyl.
“Aroyl” means an aryl-C(O)— group in which the aryl group is as previously described. The bond to the parent moiety is through the carbonyl. Non-limiting examples of suitable groups include benzoyl and 1-naphthoyl.
“Alkoxy” means an alkyl-O— group in which the alkyl group is as previously described. Non-limiting examples of suitable alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy and n-butoxy. The bond to the parent moiety is through the ether oxygen.
“Aryloxy” means an aryl-O— group in which the aryl group is as previously described. Non-limiting examples of suitable aryloxy groups include phenoxy and naphthoxy. The bond to the parent moiety is through the ether oxygen.
“Aralkyloxy” means an aralkyl-O— group in which the aralkyl group is as previously described. Non-limiting examples of suitable aralkyloxy groups include benzyloxy and 1- or 2-naphthalenemethoxy. The bond to the parent moiety is through the ether oxygen.
“Alkylthio” means an alkyl-S— group in which the alkyl group is as previously described. Non-limiting examples of suitable alkylthio groups include methylthio and ethylthio. The bond to the parent moiety is through the sulfur.
“Arylthio” means an aryl-S— group in which the aryl group is as previously described. Non-limiting examples of suitable arylthio groups include phenylthio and naphthylthio. The bond to the parent moiety is through the sulfur.
“Aralkylthio” means an aralkyl-S— group in which the aralkyl group is as previously described. Non-limiting example of a suitable aralkylthio group is benzylthio. The bond to the parent moiety is through the sulfur.
“Alkoxycarbonyl” means an alkyl-O—CO— group. Non-limiting examples of suitable alkoxycarbonyl groups include methoxycarbonyl and ethoxycarbonyl. The bond to the parent moiety is through the carbonyl.
“Aryloxycarbonyl” means an aryl-O—C(O)— group. Non-limiting examples of suitable aryloxycarbonyl groups include phenoxycarbonyl and naphthoxycarbonyl. The bond to the parent moiety is through the carbonyl.
“Aralkoxycarbonyl” means an aralkyl-O—C(O)— group. Non-limiting example of a suitable aralkoxycarbonyl group is benzyloxycarbonyl. The bond to the parent moiety is through the carbonyl.
“Alkylsulfonyl” means an alkyl-S(O 2 )— group. Preferred groups are those in which the alkyl group is lower alkyl. The bond to the parent moiety is through the sulfonyl.
“Arylsulfonyl” means an aryl-S(O 2 )— group. The bond to the parent moiety is through the sulfonyl.
The term “substituted” means that one or more hydrogens on the designated atom is replaced with a selection from the indicated group, provided that the designated atom's normal valency under the existing circumstances is not exceeded, and that the substitution results in a stable compound. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds. By “stable compound” or “stable structure” is meant a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent.
The term “optionally substituted” means optional substitution with the specified groups, radicals or moieties.
The term “purified”, “in purified form” or “in isolated and purified form” for a compound refers to the physical state of said compound after being isolated from a synthetic process (e.g. from a reaction mixture), or natural source or combination thereof. Thus, the term “purified”, “in purified form” or “in isolated and purified form” for a compound refers to the physical state of said compound after being obtained from a purification process or processes described herein or well known to the skilled artisan (e.g., chromatography, recrystallization and the like), in sufficient purity to be characterizable by standard analytical techniques described herein or well known to the skilled artisan.
It should also be noted that any carbon as well as heteroatom with unsatisfied valences in the text, schemes, examples and Tables herein is assumed to have the sufficient number of hydrogen atom(s) to satisfy the valences.
When a functional group in a compound is termed “protected”, this means that the group is in modified form to preclude undesired side reactions at the protected site when the compound is subjected to a reaction. Suitable protecting groups will be recognized by those with ordinary skill in the art as well as by reference to standard textbooks such as, for example, T. W. Greene et al, Protective Groups in Organic Synthesis (1991), Wiley, New York.
When any variable (e.g., aryl, heterocycle, R 2 , etc.) occurs more than one time in any constituent or in Formula I, its definition on each occurrence is independent of its definition at every other occurrence.
As used herein, the term “composition” is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in the specified amounts.
Prodrugs and solvates of the compounds of the invention are also contemplated herein. A discussion of prodrugs is provided in T. Higuchi and V. Stella, Pro - drugs as Novel Delivery Systems (1987) 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design , (1987) Edward B. Roche, ed., American Pharmaceutical Association and Pergamon Press. The term “prodrug” means a compound (e.g, a drug precursor) that is transformed in vivo to yield a compound of Formula (I) or a pharmaceutically acceptable salt, hydrate or solvate of the compound. The transformation may occur by various mechanisms (e.g., by metabolic or chemical processes), such as, for example, through hydrolysis in blood. A discussion of the use of prodrugs is provided by T. Higuchi and W. Stella, “Pro-drugs as Novel Delivery Systems,” Vol. 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987.
For example, if a compound of Formula (I) or a pharmaceutically acceptable salt, hydrate or solvate of the compound contains a carboxylic acid functional group, a prodrug can comprise an ester formed by the replacement of the hydrogen atom of the acid group with a group such as, for example, (C 1 -C 8 )alkyl, (C 2 -C 12 )alkanoyloxymethyl, 1-(alkanoyloxy)ethyl having from 4 to 9 carbon atoms, 1-methyl-1-(alkanoyloxy)-ethyl having from 5 to 10 carbon atoms, alkoxycarbonyloxymethyl having from 3 to 6 carbon atoms, 1-(alkoxycarbonyloxy)ethyl having from 4 to 7 carbon atoms, 1-methyl-1-(alkoxycarbonyloxy)ethyl having from 5 to 8 carbon atoms, N-(alkoxycarbonyl)aminomethyl having from 3 to 9 carbon atoms, 1-(N-(alkoxycarbonyl)amino)ethyl having from 4 to 10 carbon atoms, 3-phthalidyl, 4-crotonolactonyl, gamma-butyrolacton-4-yl, di-N,N—(C 1 -C 2 )alkylamino(C 2 -C 3 )alkyl (such as β-dimethylaminoethyl), carbamoyl-(C 1 -C 2 )alkyl, N,N-di(C 1 -C 2 )alkylcarbamoyl-(C 1 -C 2 )alkyl and piperidino-, pyrrolidino- or morpholino(C 2 -C 3 )alkyl, and the like.
Similarly, if a compound of Formula (I) contains an alcohol functional group, a prodrug can be formed by the replacement of the hydrogen atom of the alcohol group with a group such as, for example, (C 1 -C 6 )alkanoyloxymethyl, 1-((C 1 -C 6 )alkanoyloxy)ethyl, 1-methyl-1-((C 1 -C 6 )alkanoyloxy)ethyl, (C 1 -C 6 )alkoxycarbonyloxymethyl, N—(C 1 -C 6 )alkoxycarbonylaminomethyl, succinoyl, (C 1 -C 6 )alkanoyl, α-amino(C 1 -C 4 )alkanyl, arylacyl and α-aminoacyl, or α-aminoacyl-α-aminoacyl, where each α-aminoacyl group is independently selected from the naturally occurring L-amino acids, P(O)(OH) 2 , —P(O)(O(C 1 -C 6 )alkyl) 2 or glycosyl (the radical resulting from the removal of a hydroxyl group of the hemiacetal form of a carbohydrate), and the like.
If a compound of Formula (I) incorporates an amine functional group, a prodrug can be formed by the replacement of a hydrogen atom in the amine group with a group such as, for example, R-carbonyl, RO-carbonyl, NRR′-carbonyl where R and R′ are each independently (C 1 -C 10 )alkyl, (C 3 -C 7 ) cycloalkyl, benzyl, or R-carbonyl is a natural α-aminoacyl or natural α-aminoacyl, —C(OH)C(O)OY 1 wherein Y 1 is H, (C 1 -C 6 )alkyl or benzyl, —C(OY 2 )Y 3 wherein Y 2 is (C 1 -C 4 ) alkyl and Y 3 is (C 1 -C 6 )alkyl, carboxy(C 1 -C 6 )alkyl, amino(C 1 -C 4 )alkyl or mono-N— or di-N,N—(C 1 -C 6 )alkylaminoalkyl, —C(Y 4 )Y 5 wherein Y 4 is H or methyl and Y 5 is mono-N— or di-N,N—(C 1 -C 6 )alkylamino morpholino, piperidin-1-yl or pyrrolidin-1-yl, and the like.
One or more compounds of the invention may exist in unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like, and it is intended that the invention embrace both solvated and unsolvated forms. “Solvate” means a physical association of a compound of this invention with one or more solvent molecules. This physical association involves varying degrees of ionic and covalent bonding, including hydrogen bonding. In certain instances the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. “Solvate” encompasses both solution-phase and isolatable solvates. Non-limiting examples of suitable solvates include ethanolates, methanolates, and the like. “Hydrate” is a solvate wherein the solvent molecule is H 2 O.
One or more compounds of the invention may optionally be converted to a solvate. Preparation of solvates is generally known. Thus, for example, M. Caira et al, J. Pharmaceutical Sci., 93(3), 601-611 (2004) describe the preparation of the solvates of the antifungal fluconazole in ethyl acetate as well as from water. Similar preparations of solvates, hemisolvate, hydrates and the like are described by E. C. van Tonder et al, AAPS PharmSciTech., 5(1), article 12 (2004); and A. L. Bingham et al, Chem. Commun., 603-604 (2001). A typical, non-limiting, process involves dissolving the inventive compound in desired amounts of the desired solvent (organic or water or mixtures thereof) at a higher than ambient temperature, and cooling the solution at a rate sufficient to form crystals which are then isolated by standard methods. Analytical techniques such as, for example I. R. spectroscopy, show the presence of the solvent (or water) in the crystals as a solvate (or hydrate).
“Effective amount” or “therapeutically effective amount” is meant to describe an amount of compound or a composition of the present invention effective in inhibiting the above-noted diseases and thus producing the desired therapeutic, ameliorative, inhibitory or preventative effect.
The compounds of Formula I can form salts which are also within the scope of this invention. Reference to a compound of Formula I herein is understood to include reference to salts thereof, unless otherwise indicated. The term “salt(s)”, as employed herein, denotes acidic salts formed with inorganic and/or organic acids, as well as basic salts formed with inorganic and/or organic bases. In addition, when a compound of Formula I contains both a basic moiety, such as, but not limited to a pyridine or imidazole, and an acidic moiety, such as, but not limited to a carboxylic acid, zwitterions (“inner salts”) may be formed and are included within the term “salt(s)” as used herein. Pharmaceutically acceptable (i.e., non-toxic, physiologically acceptable) salts are preferred, although other salts are also useful. Salts of the compounds of the Formula I may be formed, for example, by reacting a compound of Formula I with an amount of acid or base, such as an equivalent amount, in a medium such as one in which the salt precipitates or in an aqueous medium followed by lyophilization.
Exemplary acid addition salts include acetates, ascorbates, benzoates, benzenesulfonates, bisulfates, borates, butyrates, citrates, camphorates, camphorsulfonates, fumarates, hydrochlorides, hydrobromides, hydroiodides, lactates, maleates, methanesulfonates, naphthalenesulfonates, nitrates, oxalates, phosphates, propionates, salicylates, succinates, sulfates, tartarates, thiocyanates, toluenesulfonates (also known as tosylates,) and the like. Additionally, acids which are generally considered suitable for the formation of pharmaceutically useful salts from basic pharmaceutical compounds are discussed, for example, by P. Stahl et al, Camille G. (eds.) Handbook of Pharmaceutical Salts. Properties, Selection and Use . (2002) Zurich: Wiley-VCH; S. Berge et al, Journal of Pharmaceutical Sciences (1977) 66(1) 1-19; P. Gould, International J. of Pharmaceutics (1986) 33 201-217; Anderson et al, The Practice of Medicinal Chemistry (1996), Academic Press, New York; and in The Orange Book (Food & Drug Administration, Washington, D.C. on their website). These disclosures are incorporated herein by reference thereto.
Exemplary basic salts include ammonium salts, alkali metal salts such as sodium, lithium, and potassium salts, alkaline earth metal salts such as calcium and magnesium salts, salts with organic bases (for example, organic amines) such as dicyclohexylamines, t-butyl amines, and salts with amino acids such as arginine, lysine and the like. Basic nitrogen-containing groups may be quarternized with agents such as lower alkyl halides (e.g. methyl, ethyl, and butyl chlorides, bromides and iodides), dialkyl sulfates (e.g. dimethyl, diethyl, and dibutyl sulfates), long chain halides (e.g. decyl, lauryl, and stearyl chlorides, bromides and iodides), aralkyl halides (e.g. benzyl and phenethyl bromides), and others.
All such acid salts and base salts are intended to be pharmaceutically acceptable salts within the scope of the invention and all acid and base salts are considered equivalent to the free forms of the corresponding compounds for purposes of the invention.
Pharmaceutically acceptable esters of the present compounds include the following groups: (1) carboxylic acid esters obtained by esterification of the hydroxy groups, in which the non-carbonyl moiety of the carboxylic acid portion of the ester grouping is selected from straight or branched chain alkyl (for example, acetyl, n-propyl, t-butyl, or n-butyl), alkoxyalkyl (for example, methoxymethyl), aralkyl (for example, benzyl), aryloxyalkyl (for example, phenoxymethyl), aryl (for example, phenyl optionally substituted with, for example, halogen, C 1-4 alkyl, or C 1-4 alkoxy or amino); (2) sulfonate esters, such as alkyl- or aralkylsulfonyl (for example, methanesulfonyl); (3) amino acid esters (for example, L-valyl or L-isoleucyl); (4) phosphonate esters and (5) mono-, di- or triphosphate esters. The phosphate esters may be further esterified by, for example, a C 1-20 alcohol or reactive derivative thereof, or by a 2,3-di(C 6-24 )acyl glycerol.
Compounds of Formula I, and salts, solvates, esters and prodrugs thereof, may exist in their tautomeric form (for example, as an amide or imino ether). All such tautomeric forms are contemplated herein as part of the present invention.
The compounds of Formula (I) may contain asymmetric or chiral centers, and, therefore, exist in different stereoisomeric forms. It is intended that all stereoisomeric forms of the compounds of Formula (I) as well as mixtures thereof, including racemic mixtures, form part of the present invention. In addition, the present invention embraces all geometric and positional isomers. For example, if a compound of Formula (I) incorporates a double bond or a fused ring, both the cis- and trans-forms, as well as mixtures, are embraced within the scope of the invention.
Diastereomeric mixtures can be separated into their individual diastereomers on the basis of their physical chemical differences by methods well known to those skilled in the art, such as, for example, by chromatography and/or fractional crystallization. Enantiomers can be separated by converting the enantiomeric mixture into a diastereomeric mixture by reaction with an appropriate optically active compound (e.g., chiral auxiliary such as a chiral alcohol or Mosher's acid chloride), separating the diastereomers and converting (e.g., hydrolyzing) the individual diastereomers to the corresponding pure enantiomers. Also, some of the compounds of Formula (I) may be atropisomers (e.g., substituted biaryls) and are considered as part of this invention. Enantiomers can also be separated by use of chiral HPLC column.
It is also possible that the compounds of Formula (I) may exist in different tautomeric forms, and all such forms are embraced within the scope of the invention. Also, for example, all keto-enol and imine-enamine forms of the compounds are included in the invention.
All stereoisomers (for example, geometric isomers, optical isomers and the like) of the present compounds (including those of the salts, solvates, esters and prodrugs of the compounds as well as the salts, solvates and esters of the prodrugs), such as those which may exist due to asymmetric carbons on various substituents, including enantiomeric forms (which may exist even in the absence of asymmetric carbons), rotameric forms, atropisomers, and diastereomeric forms, are contemplated within the scope of this invention, as are positional isomers (such as, for example, 4-pyridyl and 3-pyridyl). (For example, if a compound of Formula (I) incorporates a double bond or a fused ring, both the cis- and trans-forms, as well as mixtures, are embraced within the scope of the invention. Also, for example, all keto-enol and imine-enamine forms of the compounds are included in the invention.) Individual stereoisomers of the compounds of the invention may, for example, be substantially free of other isomers, or may be admixed, for example, as racemates or with all other, or other selected, stereoisomers. The chiral centers of the present invention can have the S or R configuration as defined by the IUPAC 1974 Recommendations. The use of the terms “salt”, “solvate”, “ester”, “prodrug” and the like, is intended to equally apply to the salt, solvate, ester and prodrug of enantiomers, stereoisomers, rotamers, tautomers, positional isomers, racemates or prodrugs of the inventive compounds.
The present invention also embraces isotopically-labelled compounds of the present invention which are identical to those recited herein, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, fluorine and chlorine, such as 2 H, 3 H, 13 C, 14 C, 15 N, 18 O, 17 O, 31 P, 32 P, 35 S, 18 F, and 36 Cl, respectively.
Certain isotopically-labelled compounds of Formula (I) (e.g., those labeled with 3 H and 14 C) are useful in compound and/or substrate tissue distribution assays. Tritiated (i.e., 3 H) and carbon-14 (i.e., 14 C) isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium (i.e., 2 H) may afford certain therapeutic advantages resulting from greater metabolic stability (e.g., increased in vivo half-life or reduced dosage requirements) and hence may be preferred in some circumstances. Isotopically labelled compounds of Formula (I) can generally be prepared by following procedures analogous to those disclosed in the Schemes and/or in the Examples hereinbelow, by substituting an appropriate isotopically labelled reagent for a non-isotopically labelled reagent.
Polymorphic forms of the compounds of Formula I, and of the salts, solvates, esters and prodrugs of the compounds of Formula I, are intended to be included in the present invention.
The compounds according to the invention have pharmacological properties; in particular, the compounds of Formula I can be inhibitors of 11β-hydroxysteroid dehydrogenase type I.
The term “obesity” as used herein, refers to a patient being overweight and having a body mass index (BMI) of 25 or greater. In one embodiment, an obese patient has a BMI of 25 or greater. In another embodiment, an obese patient has a BMI from 25 to 30. In another embodiment, an obese patient has a BMI greater than 30. In still another embodiment, an obese patient has a BMI greater than 40.
The term “obesity-related disorder” as used herein refers to: (i) disorders which result from a patient having a BMI of 25 or greater; and (ii) eating disorders and other disorders associated with excessive food intake. Non-limiting examples of an obesity-related disorder include edema, shortness of breath, sleep apnea, skin disorders and high blood pressure.
The term “metabolic syndrome” as used herein, refers to a set of risk factors that make a patient more susceptible to cardiovascular disease and/or type 2 diabetes. A patient is said to have metabolic syndrome if the patient has one or more of the following five risk factors:
1) central/abdominal obesity as measured by a waist circumference of greater than 40 inches in a male and greater than 35 inches in a female; 2) a fasting triglyceride level of greater than or equal to 150 mg/dL; 3) an HDL cholesterol level in a male of less than 40 mg/dL or in a female of less than 50 mg/dL; 4) blood pressure greater than or equal to 130/85 mm Hg; and 5) a fasting glucose level of greater than or equal to 110 mg/dL.
A preferred dosage is about 0.001 to 5 mg/kg of body weight/day of the compound of Formula I. An especially preferred dosage is about 0.01 to 5 mg/kg of body weight/day of a compound of Formula I, or a pharmaceutically acceptable salt, solvate, ester or prodrug of said compound.
In one embodiment, the present invention provides methods for treating a Condition in a patient, the method comprising administering to the patient one or more compounds of Formula I, or a pharmaceutically acceptable salt or solvate thereof and at least one additional therapeutic agent that is not a compound of Formula I, wherein the amounts administered are together effective to treat or prevent a Condition.
Non-limiting examples of additional therapeutic agents useful in the present methods for treating or preventing a Condition include, anti-obesity agents, antidiabetic agents, any agent useful for treating metabolic syndrome, any agent useful for treating a cardiovascular disease, cholesterol biosynthesis inhibitors, cholesterol absorption inhibitors, bile acid sequestrants, probucol derivatives, IBAT inhibitors, nicotinic acid receptor (NAR) agonists, ACAT inhibitors, cholesteryl ester transfer protein (CETP) inhibitors, low-denisity lipoprotein (LDL) activators, fish oil, water-soluble fibers, plant sterols, plant stanols, fatty acid esters of plant stanols, or any combination of two or more of these additional therapeutic agents.
Non-limiting examples of anti-obesity agents useful in the present methods for treating a Condition include CB1 antagonists or inverse agonists such as rimonabant, neuropeptide Y antagonists, MCR4 agonists, MCH receptor antagonists, histamine H 3 receptor antagonists or inverse agonists, metabolic rate enhancers, nutrient absorption inhibitors, leptin, appetite suppressants and lipase inhibitors.
Non-limiting examples of appetite suppressant agents useful in the present methods for treating or preventing a Condition include cannabinoid receptor 1 (CB 1 ) antagonists or inverse agonists (e.g., rimonabant); Neuropeptide Y (NPY1, NPY2, NPY4 and NPY5) antagonists; metabotropic glutamate subtype 5 receptor (mGluR5) antagonists (e.g., 2-methyl-6-(phenylethynyl)-pyridine and 3[(2-methyl-1,4-thiazol-4-yl)ethynyl]pyridine); melanin-concentrating hormone receptor (MCH1 R and MCH2R) antagonists; melanocortin receptor agonists (e.g., Melanotan-II and Mc4r agonists); serotonin uptake inhibitors (e.g., dexfenfluramine and fluoxetine); serotonin (5HT) transport inhibitors (e.g., paroxetine, fluoxetine, fenfluramine, fluvoxamine, sertaline and imipramine); norepinephrine (NE) transporter inhibitors (e.g., desipramine, talsupram and nomifensine); ghrelin antagonists; leptin or derivatives thereof; opioid antagonists (e.g., nalmefene, 3-methoxynaltrexone, naloxone and nalterxone); orexin antagonists; bombesin receptor subtype 3 (BRS3) agonists; Cholecystokinin-A (CCK-A) agonists; ciliary neurotrophic factor (CNTF) or derivatives thereof (e.g.; butabindide and axokine); monoamine reuptake inhibitors (e.g., sibutramine); glucagon-like peptide 1 (GLP-1) agonists; topiramate; and phytopharm compound 57.
Non-limiting examples of metabolic rate enhancers useful in the present methods for treating or preventing a Condition include acetyl-CoA carboxylase-2 (ACC2) inhibitors; beta adrenergic receptor 3 (133) agonists; diacylglycerol acyltransferase inhibitors (DGAT1 and DGAT2); fatty acid synthase (FAS) inhibitors (e.g., Cerulenin); phosphodiesterase (PDE) inhibitors (e.g., theophylline, pentoxifylline, zaprinast, sildenafil, aminone, milrinone, cilostamide, rolipram and cilomilast); thyroid hormone β agonists; uncoupling protein activators (UCP-1, 2 or 3) (e.g., phytanic acid, 4-[(E)-2-(5,6,7,8-tetramethyl-2-naphthalenyl)-1-propenyl]benzoic acid and retinoic acid); acyl-estrogens (e.g., oleoyl-estrone); glucocorticoid antagonists; 11-beta hydroxy steroid dehydrogenase type 1 (11β HSD-1) inhibitors; melanocortin-3 receptor (Mc3r) agonists; and stearoyl-CoA desaturase-1 (SCD-1) compounds.
Non-limiting examples of nutrient absorption inhibitors useful in the present methods for treating or preventing a Condition include lipase inhibitors (e.g., orlistat, lipstatin, tetrahydrolipstatin, teasaponin and diethylumbelliferyl phosphate); fatty acid transporter inhibitors; dicarboxylate transporter inhibitors; glucose transporter inhibitors; and phosphate transporter inhibitors.
Non-limiting examples of cholesterol biosynthesis inhibitors useful in the present methods for treating or preventing a Condition include HMG-CoA reductase inhibitors, squalene synthase inhibitors, squalene epoxidase inhibitors and mixtures thereof.
Non-limiting examples of cholesterol absorption inhibitors useful in the present methods for treating or preventing a Condition include ezetimibe and other compounds suitable for the same purpose. In one embodiment, the cholesterol absorption inhibitor is ezetimibe.
HMG-CoA reductase inhibitors useful in the present methods for treating or preventing a Condition include, but are not limited to, statins such as lovastatin, pravastatin, fluvastatin, simvastatin, atorvastatin, cerivastatin, CI-981, resuvastatin, rivastatin, pitavastatin, rosuvastatin or L-659,699 ((E,E)-11-[3′R-(hydroxy-methyl)-4′-oxo-2′R-oxetanyl]-3,5,7R-trimethyl-2,4-undecadienoic acid).
Squalene synthesis inhibitors useful in the present methods for treating or preventing a Condition include, but are not limited to, squalene synthetase inhibitors; squalestatin 1; and squalene epoxidase inhibitors, such as NB-598 ((E)-N-ethyl-N-(6,6-dimethyl-2-hepten-4-ynyl)-3-[(3,3′-bithiophen-5-yl)methoxy]benzene-methanamine hydrochloride).
Bile acid sequestrants useful in the present methods for treating or preventing a Condition include, but are not limited to, cholestyramine (a styrene-divinylbenzene copolymer containing quaternary ammonium cationic groups capable of binding bile acids, such as QUESTRAN® or QUESTRAN LIGHT® cholestyramine which are available from Bristol-Myers Squibb), colestipol (a copolymer of diethylenetriamine and 1-chloro-2,3-epoxypropane, such as COLESTID® tablets which are available from Pharmacia), colesevelam hydrochloride (such as WelChol® Tablets (poly(allylamine hydrochloride) cross-linked with epichlorohydrin and alkylated with 1-bromodecane and (6-bromohexyl)-trimethylammonium bromide) which are available from Sankyo), water soluble derivatives such as 3,3-ioene, N-(cycloalkyl) alkylamines and poliglusam, insoluble quaternized polystyrenes, saponins and mixtures thereof. Suitable inorganic cholesterol sequestrants include bismuth salicylate plus moritmorillonite clay, aluminum hydroxide and calcium carbonate antacids.
Probucol derivatives useful in the present methods for treating or preventing a Condition include, but are not limited to, AGI-1067 and others disclosed in U.S. Pat. Nos. 6,121,319 and 6,147,250.
IBAT inhibitors useful in the present methods for treating or preventing a Condition include, but are not limited to, benzothiepines such as therapeutic compounds comprising a 2,3,4,5-tetrahydro-1-benzothiepine 1,1-dioxide structure such as are disclosed in International Publication No. WO 00/38727.
Nicotinic acid receptor agonists useful in the present methods for treating or preventing a Condition include, but are not limited to, those having a pyridine-3-carboxylate structure or a pyrazine-2-carboxylate structure, including acid forms, salts, esters, zwitterions and tautomers, where available. Other examples of nicotinic acid receptor agonists useful in the present methods include nicotinic acid, niceritrol, nicofuranose and acipimox. An example of a suitable nicotinic acid product is NIASPAN® (niacin extended-release tablets) which are available from Kos Pharmaceuticals, Inc. (Cranbury, N.J.).
ACAT inhibitors useful in the present methods for treating or preventing a Condition include, but are not limited to, avasimibe, HL-004, lecimibide and CL-277082 (N-(2,4-difluorophenyl)-N-[[4-(2,2-dimethylpropyl)phenyl]-methyl]-N-heptylurea). See P. Chang et al., “Current, New and Future Treatments in Dyslipidaemia and Atherosclerosis”, Drugs 2000 July; 60(1); 55-93, which is incorporated by reference herein.
CETP inhibitors useful in the present methods for treating or preventing a Condition include, but are not limited to, those disclosed in International Publication No. WO 00/38721 and U.S. Pat. No. 6,147,090, which are incorporated herein by reference.
LDL-receptor activators useful in the present methods for treating or preventing a Condition include, but are not limited to, include HOE-402, an imidazolidinyl-pyrimidine derivative that directly stimulates LDL receptor activity. See M. Huettinger et al., “Hypolipidemic activity of HOE-402 is Mediated by Stimulation of the LDL Receptor Pathway”, Arterioscler. Thromb. 1993; 13:1005-12.
Natural water-soluble fibers useful in the present methods for treating or preventing a Condition include, but are not limited to, psyllium, guar, oat and pectin.
Fatty acid esters of plant stanols useful in the present methods for treating or preventing a Condition include, but are not limited to, the sitostanol ester used in BENECOL® margarine.
Non-limiting examples of antidiabetic agents useful in the present methods for treating a Condition include insulin sensitizers, β-glucosidase inhibitors, DPP-IV inhibitors, insulin secretagogues, hepatic glucose output lowering compounds, antihypertensive agents, sodium glucose uptake transporter 2 (SGLT-2) inhibitors, insulin and insulin-containing compositions, and anti-obesity agents as set forth above.
In one embodiment, the antidiabetic agent is an insulin secretagogue. In one embodiment, the insulin secretagogue is a sulfonylurea.
Non-limiting examples of sulfonylureas useful in the present methods include glipizide, tolbutamide, glyburide, glimepiride, chlorpropamide, acetohexamide, gliamilide, gliclazide, gliquidone, glibenclamide and tolazamide.
In another embodiment, the insulin secretagogue is a meglitinide.
Non-limiting examples of meglitinides useful in the present methods for treating a Condition include repaglinide, mitiglinide, and nateglinide.
In still another embodiment, the insulin secretagogue is GLP-1 or a GLP-1 mimetic.
Non-limiting examples of GLP-1 mimetics useful in the present methods include Byetta-Exanatide, Liraglutinide, CJC-1131 (ConjuChem, Exanatide-LAR (Amylin), BIM-51077 (Ipsen/LaRoche), ZP-10 (Zealand Pharmaceuticals), and compounds disclosed in International Publication No. WO 00/07617.
Other non-limiting examples of insulin secretagogues useful in the present methods include exendin, GIP and secretin.
In another embodiment, the antidiabetic agent is an insulin sensitizer.
Non-limiting examples of insulin sensitizers useful in the present methods include PPAR activators or agonists, such as troglitazone, rosiglitazone, pioglitazone and englitazone; biguanidines such as metformin and phenformin; PTP-1 B inhibitors; and glucokinase activators.
In another embodiment, the antidiabetic agent is a β-Glucosidase inhibitor.
Non-limiting examples of β-Glucosidase inhibitors useful the present methods include miglitol, acarbose, and voglibose.
In another embodiment, the antidiabetic agent is an hepatic glucose output lowering agent.
Non-limiting examples of hepatic glucose output lowering agents useful in the present methods include Glucophage and Glucophage XR.
In yet another embodiment, the antidiabetic agent is insulin, including all formualtions of insulin, such as long acting and short acting forms of insulin.
Non-limiting examples of orally administrable insulin and insulin containing compositions include AL-401 from Autoimmune, and the compositions disclosed in U.S. Pat. Nos. 4,579,730; 4,849,405; 4,963,526; 5,642,868; 5,763,396; 5,824,638; 5,843,866; 6,153,632; 6,191,105; and International Publication No. WO 85/05029, each of which is incorporated herein by reference.
In another embodiment, the antidiabetic agent is a DPP-IV inhibitor.
Non-limiting examples of DPP-IV inhibitors useful in the present methods include sitagliptin, saxagliptin, denagliptin, vildagliptin, alogliptin, alogliptin benzoate, Galvus (Novartis), ABT-279 and ABT-341 (Abbott), ALS-2-0426 (Alantos), ARI-2243 (Arisaph), BI-A and BI-B (Boehringer Ingelheim), SYR-322 (Takeda), MP-513 (Mitsubishi), DP-893 (Pfizer) and RO-0730699 (Roche).
In a further embodiment, the antidiabetic agent is a SGLT-2 inhibitor.
Non-limiting examples of SGLT-2 inhibitors useful in the present methods include dapagliflozin and sergliflozin, AVE2268 (Sanofi-Aventis) and T-1095 (Tanabe Seiyaku).
Non-limiting examples of antihypertensive agents useful in the present methods for treating a Condition include β-blockers and calcium channel blockers (for example diltiazem, verapamil, nifedipine, amlopidine, and mybefradil), ACE inhibitors (for example captopril, lisinopril, enalapril, spirapril, ceranopril, zefenopril, fosinopril, cilazopril, and quinapril), AT-1 receptor antagonists (for example losartan, irbesartan, and valsartan), renin inhibitors and endothelin receptor antagonists (for example sitaxsentan).
In one embodiment, the antidiabetic agent is an agent that slows or blocks the breakdown of starches and certain sugars.
Non-limiting examples of antidiabetic agents that slow or block the breakdown of starches and certain sugars and are suitable for use in the compositions and methods of the present invention include alpha-glucosidase inhibitors and certain peptides for increasing insulin production. Alpha-glucosidase inhibitors help the body to lower blood sugar by delaying the digestion of ingested carbohydrates, thereby resulting in a smaller rise in blood glucose concentration following meals. Non-limiting examples of suitable alpha-glucosidase inhibitors include acarbose; miglitol; camiglibose; certain polyamines as disclosed in WO 01/47528 (incorporated herein by reference); voglibose. Non-limiting examples of suitable peptides for increasing insulin production including amlintide (CAS Reg. No. 122384-88-7 from Amylin; pramlintide, exendin, certain compounds having Glucagon-like peptide-1 (GLP-1) agonistic activity as disclosed in International Publication No. WO 00/07617.
Other specific additional therapeutic agents useful in the present methods for treating or preventing a Condition include, but are not limited to, rimonabant, 2-methyl-6-(phenylethynyl)-pyridine, 3[(2-methyl-1,4-thiazol-4-yl)ethynyl]pyridine, Melanotan-II, dexfenfluramine, fluoxetine, paroxetine, fenfluramine, fluvoxamine, sertaline, imipramine, desipramine, talsupram, nomifensine, leptin, nalmefene, 3-methoxynaltrexone, naloxone, nalterxone, butabindide, axokine, sibutramine, topiramate, phytopharm compound 57, Cerulenin, theophylline, pentoxifylline, zaprinast, sildenafil, aminone, milrinone, cilostamide, rolipram, cilomilast, phytanic acid, 4-[(E)-2-(5,6,7,8-tetramethyl-2-naphthalenyl)-1-propenyl]benzoic acid, retinoic acid, oleoyl-estrone, orlistat, lipstatin, tetrahydrolipstatin, teasaponin and diethylumbelliferyl phosphate.
In one embodiment, the present combination therapies for treating or preventing diabetes comprise administering a compound of formula (I), an antidiabetic agent and/or an antiobesity agent.
In another embodiment, the present combination therapies for treating or preventing diabetes comprise administering a compound of formula (I) and an antidiabetic agent.
In another embodiment, the present combination therapies for treating or preventing diabetes comprise administering a compound of formula (I) and an anti-obesity agent.
In one embodiment, the present combination therapies for treating or preventing obesity comprise administering a compound of formula (I), an antidiabetic agent and/or an antiobesity agent.
In another embodiment, the present combination therapies for treating or preventing obesity comprise administering a compound of formula (I) and an antidiabetic agent.
In another embodiment, the present combination therapies for treating or preventing obesity comprise administering a compound of formula (I) and an anti-obesity agent.
In one embodiment, the present combination therapies for treating or preventing metabolic syndrome comprise administering a compound of formula (I) and one or more additional therapeutic agents selected from: anti-obesity agents, antidiabetic agents, any agent useful for treating metabolic syndrome, any agent useful for treating a cardiovascular disease, cholesterol biosynthesis inhibitors, sterol absorption inhibitors, bile acid sequestrants, probucol derivatives, IBAT inhibitors, nicotinic acid receptor (NAR) agonists, ACAT inhibitors, cholesteryl ester transfer protein (CETP) inhibitors, low-denisity lipoprotein (LDL) activators, fish oil, water-soluble fibers, plant sterols, plant stanols and fatty acid esters of plant stanols.
In one embodiment, the additional therapeutic agent is a cholesterol biosynthesis inhibitor. In another embodiment, the cholesterol biosynthesis inhibitor is an HMG-CoA reductase inhibitor. In another embodiment, the HMG-CoA reductase inhibitor is a statin. In another embodiment, the statin is lovastatin, pravastatin, simvastatin or atorvastatin.
In one embodiment, the additional therapeutic agent is a cholesterol absorption inhibitor. In another embodiment, the cholesterol absorption inhibitor is ezetimibe. In another embodiment, the cholesterol absorption inhibitor is a squalene synthetase inhibitor. In another embodiment, the cholesterol absorption inhibitor is a squalene epoxidase inhibitor.
In one embodiment, the additional therapeutic agent comprises a cholesterol absorption inhibitor and a cholesterol biosynthesis inhibitor. In another embodiment, the additional therapeutic agent comprises a cholesterol absorption inhibitor and a statin. In another embodiment, the additional therapeutic agent comprises ezetimibe and a statin. In another embodiment, the additional therapeutic agent comprises ezetimibe and simvastatin.
In one embodiment, the present combination therapies for treating or preventing metabolic syndrome comprise administering a compound of formula (I), an antidiabetic agent and/or an antiobesity agent.
In another embodiment, the present combination therapies for treating or preventing metabolic syndrome comprise administering a compound of formula (I) and an antidiabetic agent.
In another embodiment, the present combination therapies for treating or preventing metabolic syndrome comprise administering a compound of formula (I) and an anti-obesity agent.
In one embodiment, the present combination therapies for treating or preventing a cardiovascular disease comprise administering one or more compounds of formula (I), and an additional agent useful for treating or preventing a cardiovascular disease.
When administering a combination therapy to a patient in need of such administration, the therapeutic agents in the combination, or a pharmaceutical composition or compositions comprising the therapeutic agents, may be administered in any order such as, for example, sequentially, concurrently, together, simultaneously and the like. The amounts of the various actives in such combination therapy may be different amounts (different dosage amounts) or same amounts (same dosage amounts).
In one embodiment, the one or more compounds of Formula I are administered during a time when the additional therapeutic agent(s) exert their prophylactic or therapeutic effect, or vice versa.
In another embodiment, the one or more compounds of Formula I and the additional therapeutic agent(s) are administered in doses commonly employed when such agents are used as monotherapy for treating a Condition.
In another embodiment, the one or more compounds of Formula I and the additional therapeutic agent(s) are administered in doses lower than the doses commonly employed when such agents are used as monotherapy for treating a Condition.
In still another embodiment, the one or more compounds of Formula I and the additional therapeutic agent(s) act synergistically and are administered in doses lower than the doses commonly employed when such agents are used as monotherapy for treating a Condition.
In one embodiment, the one or more compounds of Formula I and the additional therapeutic agent(s) are present in the same composition. In one embodiment, this composition is suitable for oral administration. In another embodiment, this composition is suitable for intravenous administration.
The one or more compounds of Formula I and the additional therapeutic agent(s) can act additively or synergistically. A synergistic combination may allow the use of lower dosages of one or more agents and/or less frequent administration of one or more agents of a combination therapy. A lower dosage or less frequent administration of one or more agents may lower toxicity of the therapy without reducing the efficacy of the therapy.
In one embodiment, the administration of one or more compounds of Formula I and the additional therapeutic agent(s) may inhibit the resistance of a Condition to these agents.
In one embodiment, when the patient is treated for diabetes or a diabetic complication, the additional therapeutic agent is an antidiabetic agent which is not a compound of Formula I. In another embodiment, the additional therapeutic agent is an agent useful for reducing any potential side effect of a compound of Formula I. Such potential side effects include, but are not limited to, nausea, vomiting, headache, fever, lethargy, muscle aches, diarrhea, general pain, and pain at an injection site.
The pharmacological properties of the compounds of this invention may be confirmed by a number of pharmacological assays. The exemplified pharmacological assays which are described later have been carried out with the compounds according to the invention and their salts.
The invention is also directed to pharmaceutical compositions which comprise at least one compound of Formula I, or a pharmaceutically acceptable salt, solvate, ester or prodrug of said compound and at least one pharmaceutically acceptable carrier.
The term “pharmaceutical composition” is also intended to encompass both the bulk composition and individual dosage units comprised of more than one (e.g., two) pharmaceutically active agents such as, for example, a compound of the present invention and an additional agent selected from the lists of the additional agents described herein, along with any pharmaceutically inactive excipients. The bulk composition and each individual dosage unit can contain fixed amounts of the afore-said “more than one pharmaceutically active agents”. The bulk composition is material that has not yet been formed into individual dosage units. An illustrative dosage unit is an oral dosage unit such as tablets, pills and the like. Similarly, the herein-described method of treating a patient by administering a pharmaceutical composition of the present invention is also intended to encompass the administration of the afore-said bulk composition and individual dosage units.
For preparing pharmaceutical compositions from the compounds described by this invention, inert, pharmaceutically acceptable carriers can be either solid or liquid. Solid form preparations include powders, tablets, dispersible granules, capsules, cachets and suppositories. The powders and tablets may be comprised of from about 5 to about 95 percent active ingredient. Suitable solid carriers are known in the art, e.g., magnesium carbonate, magnesium state, talc, sugar or lactose. Tablets, powders, cachets and capsules can be used as solid dosage forms suitable for oral administration. Examples of pharmaceutically acceptable carriers and methods of manufacture for various compositions may be found in A. Gennaro (ed.), Remington's Pharmaceutical Sciences, 18 th Edition, (1990), Mack Publishing Co., Easton, Pa.
Liquid form preparations include solutions, suspensions and emulsions. As an example may be mentioned water or water-propylene glycol solutions for parenteral injection or addition of sweeteners and opacifiers for oral solutions, suspensions and emulsions. Liquid form preparations may also intranasal administration.
Aerosol preparations suitable for inhalation may include solutions and solids in powder form, which may be in combination with a pharmaceutically acceptable carrier, such as an inert compressed gas, e.g. nitrogen.
Also included are solid form preparations that are intended to be converted, shortly before use, to liquid form preparations for either oral or parenteral administration. Such liquid forms include solutions, suspensions and emulsions.
The compounds of the invention may also be deliverable transdermally.
The transdermal compositions can take the form of creams, lotions, aerosols and/or emulsions and can be included in a transdermal patch of the matrix or reservoir type as are conventional in the art for this purpose.
The compounds of this invention may also be delivered subcutaneously.
Preferably the compound is administered orally.
Preferably, the pharmaceutical preparation is in a unit dosage form. In such form, the preparation is subdivided into suitable sized unit doses containing appropriate quantities of the active component, e.g. an effective amount to achieve the desired purpose.
The quantity of active compound in a unit dose of preparation may be varied or adjusted from about 1 mg to about 100 mg, preferably from about 1 mg to about 50 mg, more preferably from about 1 mg to about 25 mg, according to the particular application.
The actual dosage employed may be varied depending upon the requirements of the patient and the severity of the condition being treated. Determination of the proper dosage regimen for a particular situation is within the skill of the art. For convenience, the total daily dosage may be divided and administered in portions during the day as required.
The amount and frequency of administration of the compounds of the invention and/or the pharmaceutically acceptable salts thereof will be regulated according to the judgment of the attending clinician considering such factors as age, condition and size of the patient as well as severity of the symptoms being treated. A typical recommended daily dosage regimen for oral administration can range from about 1 mg/day to about 500 mg/day, preferably 1 mg/day to 200 mg/day, in two to four divided doses.
Another aspect of this invention is a kit comprising a therapeutically effective amount of at least one compound of Formula I, or a pharmaceutically acceptable salt, solvate, ester or prodrug of said compound and a pharmaceutically acceptable carrier, vehicle or diluent.
Yet another aspect of this invention is a kit comprising an amount of at least one compound of Formula I, or a pharmaceutically acceptable salt, solvate, ester or prodrug of said compound and an amount of at least one therapeutic agent listed above, wherein the amounts of the two or more ingredients result in a desired therapeutic effect.
The invention disclosed herein is exemplified by the following preparations and examples which should not be construed to limit the scope of the disclosure. Alternative mechanistic pathways and analogous structures will be apparent to those skilled in the art.
Where NMR data are presented, 1 H spectra were obtained on either a Variant VXR-200 (200 MHz, 1 H), Varian Gemini-300 (300 MHZ), Varian Mercury VX-400 (400 MHz), or Bruker-Biospin AV-500(500 MHz), and are reported as ppm with number of protons and multiplicities indicated parenthetically. Where LC/MS data are presented, analyses was performed using an Applied Biosystems API-100 mass spectrometer and C18 column, 10-95% CH 3 CN—H 2 O (with 0.05% TFA) gradient. The observed parent ion is given.
The following solvents and reagents may be referred to by their abbreviations in parenthesis:
Me=methyl Et=ethyl Pr=propyl Bu=butyl Ph=phenyl Ac=acetyl μl=microliters AcOEt or EtOAc=ethyl acetate AcOH or HOAc=acetic acid ACN=acetonitrile atm=atmosphere Boc or BOC=tert-butoxycarbonyl DCE=dichloroethane DCM or CH 2 Cl 2 =dichloromethane DIPEA=diisopropylethylamine DMAP=4-dimethylaminopyridine DMF=dimethylformamide DMS=dimethylsulfide DMSO=dimethyl sulfoxide EDCI=1-(3-dimethylaminopropyl)-3-ethylcarbodiimine Fmoc or FMOC=9-fluorenylmethoxycarbonyl g=grams h=hour hal=halogen HOBt=1-hydroxybenzotriazole LAH=lithium aluminum hydride LCMS=liquid chromatography mass spectrometry min=minute mg=milligrams mL=milliliters mmol=millimoles MCPBA=3-chloroperoxybenzoic acid MeOH=methanol MS=mass spectrometry NMR=nuclear magnetic resonance spectroscopy RT or rt=room temperature (ambient, about 25° C.) TEA or Et 3 N=triethylamine TFA=trifluoroacetic acid THF=tetrahydrofuran TLC=thin layer chromatography TMS=trimethylsilyl Tr=triphenylmethyl
EXAMPLES
The compounds of this invention can be prepared as generally described in the Preparation Scheme, and the following examples.
Preparation Scheme
Polystyrene DIEA resin (47 mg, 0.045 mmol) was added to 40-wells of a deep well polypropylene microtiter plate followed by a MeCN/THF (2:1) stock solution (1 mL) of 1,3,3-trimethyl-6-azabicyclo-[3.2.1]octane X (8.0 mg, 0.05 mmol). Then 0.5 M stock solutions of each of the individual sulfonyl chlorides (R 1-45 SO 2 Cl) (0.210 mL, 0.10 mmol) were added to the wells, which was then sealed and shaken at 25° C. for 20 h. The solutions were filtered thru a polypropylene frit into a 2 nd microtiter plate containing polystyrene isocyanate resin (103 mg, 3 equivalents, 1.52 mmol/g) and polystyrene trisamine resin (74 mg, 6 equivalents, 4.23 mmol/g). After the top plate was washed with MeCN (0.5 mL), the plate was removed, the bottom microtiter plate sealed and shaken at 25° C. for 16 hrs. Then the solutions were filtered thru a polypropylene frit into a 96-well collection plate. The wells of the top plate were then washed with MeCN (2×0.5 mL), and the plate removed. Then the resultant solutions in the collection plate were transferred into vials and the solvents removed in vacuo via a SpeedVac to provide the sulfonamides.
Using this Preparation Scheme, the inventive compounds can be prepared.
Compound No. 1
To a solution of 1,3,3-trimethyl-6-azabicyclo-[3.2.1]octane (0.06 mL, 0.33 mmol) in CH 2 Cl 2 (3.3 mL) was added diisopropylethyl amine (0.17 mL, 0.99 mmol) followed by the sulfonyl chloride (0.49 mmol). The reaction was stirred at RT under nitrogen for 21 h after which it was quenched with 1 N HCl and extracted with CH 2 Cl 2 . The organics were dried over MgSO 4 , filtered and concentrated to give crude material. Purification by PTLC (15% EtOAc/hexanes) afforded the desired sulfonamide Compound No. 1 (115 mg, 100%).
Compound Nos. 2, 3, 47, 48, 51-67, 76-81 and N-(4-(1,3,3-trimethyl-6-azabicyclo[3.2.1]octan-6-ylsulfonyl)phenyl)acetamide, a compound purchased from TRIPOS, were prepared using commercially available sulfonyl chlorides in a similar manner as described for the synthesis of Compound No. 1.Yields ranged from 40 to 100%.
Separation of Compound No. 23
Compound No. 23 was prepared in the same manner as Compound No. 1.
About 90 mg of Compound No. 23 was dissolved in 5% IPA/hexanes (1.2 mL) and injected onto a chiralpak AS prep HPLC column (5 cm×50 cm) and eluted with 5% IPA/hexanes at 100 mL/min. Detection at 254 nm. 45 mg of Compound No. 54 (isomer 1, retention time=30.1 min) and 45 mg of a mixture of isomer 1 and 2 were obtained. The mixture (45 mg) was dissolved in 25% IPA/hexanes and injected onto the chiralpak AS prep column for the second time and eluted with 3% IPA/hexanes at 50 mL/min. 20.5 mg of Compound No. 55 (isomer 2, retention time=−67 min) was obtained.
Separation of Compound No. 16
Compound No. 16 was prepared in the same manner as Compound No. 1.
About 240 mg of Compound No. 16 was dissolved in 5% IPA/hexanes (1.2 mL) and injected onto a chiralpak AS prep HPLC column (5 cm×50 cm) and eluted with 15% IPA/hexanes at 75 mL/min. Detection at 254 nm. 81.3 mg of Compound No. 67 (isomer 1, retention time=46.4 min) and 102 mg of a mixture of isomer 1 and 2 were obtained. The mixture (102 mg) was dissolved in 25% IPA/hexanes and injected onto the chiralpak AS prep column for the second time and eluted with 15% IPA/hexanes at 50 mL/min. 44.0 mg of Compound No. 66 (isomer 2, retention time=86.9 min) was obtained.
Reduction of Compound No. 67
To a solution of Compound No. 67 (0.039 g, 0.12 mmol) in MeOH (1.5 mL) was added sodium borohydride (0.012 g, 0.32 mmol) at 0° C. in (ice bath). After stirring at room temperature for 1 h, the reaction was quenched with saturated ammonium chloride solution and extracted with CH 2 Cl 2 . The organic fractions were combined, dried over MgSO 4 , filtered, and concentrated to give the crude material. Purification by PTLC (2% MeOH/CH 2 Cl 2 ) yielded the desired reduction product Intermediate A as a mixture of enantiomers (33 mg, 85%).
Separation of Compound No. 67
About 18 mg of Intermediate A from the previous example was dissolved in 20% IPA/hexanes (1.0 mL) and injected onto a chiralpak AD semi-prep HPLC column and eluted with 10% IPA/hexanes at 10 mL/min. Detection at 254 nm. 7.9 mg of Compound No. 73 (isomer 1, retention time=19.1 min) and 7.3 mg of Compound No. 72 (isomer 2, retention time=22.6 min) were obtained.
Separation of Compound No. 66
Intermediate B was prepared from Compound No. 66 in the same manner as Intermediate A was prepared from Compound No. 67. Compound No. 71 (isomer 3, retention time=18.8 min, 95%) and Compound No. 70 (isomer 4, retention time=22.8 min, 5%) were prepared in the same manner as Compound No. 72 and Compound No. 73.
Preparation of Compound No. 81
To a solution of Compound No. 67 (34 mg, 0.10 mmol) in THF (2 mL) was added methylmagnesium bromide (3M in ether, 0.18 mL, 0.40 mmol). The reaction was stirred at room temperature for 1.5 h after which it was quenched with saturated ammonium chloride solution and extracted with CH 2 Cl 2 . The organic fraction was dried (MgSO 4 ), filtered, and concentrated to give a crude material. Purification by preparative TLC (25% EtOAc/Hexanes) afforded the desired compound Compound No. 81 (20.9 mg, 60%).
Compound No. 80 was prepared in the same manner as Compound No. 81 from Compound No. 66.
Preparation of Compound No. 79
NaH (6 mg, 0.25 mmol) was added to a solution of Compound No. 81 (18.2 mg, 0.050 mmol) in DMF (1 mL) at 0° C. After 15 min., iodomethane (0.01 mL, 0.10 mmol) was added and the reaction was warmed to room temperature. After 1.75 hours, the reaction was quenched with water and extracted with EtOAc. The combined organics were washed with water, dried over MgSO 4 , filtered and concentrated to give the crude material. Purification by PTLC (20% EtOAc/Hexanes) yielded the Compound No. 79 (9.0 mg, 48%).
Compound No. 78 was prepared in a similar manner as Compound No. 79 from Compound No. 80.
In vitro 11β-HSD1 activity assay
Preparation of 11β-HSD1 membranes
Human 11β-HSD1 with N-terminal myc tag was expressed in Sf9 cells using baculovirus Bac-to-Bac expression system (Invitrogen) according to manufacturer's instructions. Cells were harvested three days after infection and washed in PBS before frozen. To make membranes, the cells were resuspended in buffer A (20 mM Tris-HCl, pH7.4, 100 mM NaCl, 2 mM EDTA, 2 mM EGTA and Complete™ protease inhibitor tablets (Roche Molecular Biochemicals)), and lysed in a nitrogen bomb at 900 psi. The cell lysate was centrifuged at 600 g for 10 min to remove nuclei and large cell debris. The supernatant was centrifuged at 100,000 g for 1 hr. The membrane pellet was resuspended in buffer A, flash-frozen in liquid nitrogen and stored at −70° C. before use.
Measurement of 11β-HSD1 activity
11β-HSD1 enzymatic activity was measured in a 50 μl reaction containing 20 mM NaPO 4 pH 7.5, 0.1 mM MgCl 2 , 3 mM NADPH (prepared fresh daily), 125 nM 3 H-cortisone (American Radiochemicals) and 0.5 μg membrane. The reaction was incubated at room temperature for 1 hr before it was stopped by addition of 50 μM buffer containing 20 mM NaPO 4 pH 7.5, 30 μM 18β-glycyrrhetinic acid, 1 μg/ml monoclonal anti-cortisol antibody (Biosource) and 2 mg/ml anti-mouse antibody coated scintillation proximity assay (SPA) beads (Amersham Bioscience). The mixture was incubated at room temperature for 2 hrs with vigorous shaking and analyzed on TopCount scintillation counter.
Compounds according to the present invention showed activity against 11β-HSD1 in this assay.
In Vivo Screen for Inhibition of 11β-HSD-1
Lean male C57BI/6N mice were orally dosed with a solution of dexamethasone (0.5 mg/kg) and test agent or vehicle (20% HPβCD (10 ml/kg)). One hour later, cortisone was administered (1 mg/kg sc in sesame oil). One hour after cortisone administration, animals were euthanized for blood collection, and plasma cortisol levels were determined with a commercially available ELISA.
Compounds according to the present invention inhibited 11β-HSD1 in this screen.
Table 2 shows 11β-HSD-1 activity of representative compounds of this invention. The table and the compounds therein are not intended, nor should they be construed, to limit this invention in any manner whatsoever.
TABLE 2
Mouse cort.
Human
Mouse
challenge
11β-HSD-1
11β-HSD-1
% I
Compound No.
IC 50 (nM)
IC 50 (nM)
@ 30 mpk
29
5714
13266
76
126
1819
10
2509
3167
39
268
686
12
1415
28195
13
407
2483
5
3006
18247
6
247
670
4
3392
7926
74
5714
11136
75
126
5937
32
2509
3167
48
268
686
3
407
1875
64
340
217
61
415
165
25
169
364
63
111
305
62
96
309
9
190
420
17
67
127
1
31
71
30
23
28
19
26
65
372
950
68
55
112
16
139
732
44
16
67
63
45
19
27
16
46
10
87
50
7
43
43
49
23
11
19
69
30
68
While the present invention has been described in conjunction with the specific embodiments set forth above, many alternatives, modifications and other variations thereof will be apparent to those of ordinary skill in the art. All such alternatives, modifications and variations are intended to fall within the spirit and scope of the present invention.
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In its many embodiments, the present invention relates to a novel class of 6-substituted sulfonyl-1,3,3-trialkyl-6-azabicyclo[3.2.1]octane compounds useful to inhibit 11β-hydroxysteroid dehydrogenase type-I, pharmaceutical compositions containing the compounds, and methods of treatment, prevention, inhibition, or amelioration of one or more conditions associated with the expression of 11β-hydroxysteroid dehydrogenase type-I using such compounds or pharmaceutical compositions.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application claims priority to Korean Patent Application No. 10-2006-0090147, filed on Sep. 18, 2006, and all the benefits accruing therefrom under 35 U.S.C. §119, the content of 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 method of crystallizing a semiconductor layer, and more specifically, to a method of manufacturing a laterally crystallized semiconductor layer having good electron mobility and good electrical characteristics using a simple, easy process.
[0004] 2. Description of the Related Art
[0005] Transistors are used, for example, as switching devices in flat panel displays (FPDs), such as organic light emitting diodes (OLEDs) or liquid crystal displays (LCDs). In general, a thin film transistor (TFT) comprises a channel area, a source, and a drain formed beside both sides of the channel area, and a gate formed above the channel area.
[0006] The channel area in the TFT comprises amorphous silicon or polycrystalline silicon. Polycrystalline silicon (poly-Si) generally has higher mobility than amorphous silicon (a-Si), and thus is advantageous for operating a TFT at high-speed. Amorphous silicon may be crystallized through annealing to obtain polycrystalline silicon, and some electrical characteristics of the channel area are determined by the grain size of the polycrystalline silicon. For example, if the grain size of the polycrystalline silicon is large, the mobility of the electrons becomes greater in the channel area. Thus, some electrical characteristics of the TFT are improved.
[0007] Excimer laser annealing (ELA) has been recently used to crystallize amorphous silicon. However, increasing the grain size is limited, i.e., it is difficult to obtain a grain size of 0.5 μm or more, and it is not easy to control uniformity of the grain size.
[0008] Accordingly, crystallization methods using sequential lateral solidification (SLS), an optical phase shift mask (OPSM), a pre-patterned laser beam mask (PLBM), or the like, have been suggested. However, the crystallization methods require an apparatus for accurately adjusting substrates and multi-laser beams. Thus, it is very difficult to apply the crystallization methods to a TFT process.
SUMMARY OF THE INVENTION
[0009] In an embodiment, there is provided a method of manufacturing a laterally crystallized semiconductor layer, the method comprising: forming a semiconductor layer on a substrate; irradiating a plurality of laser beams on the semiconductor layer; splitting the laser beams using a prism sheet comprising an array of a plurality of prisms, advancing the laser beams toward the semiconductor layer to alternately form first and second areas in the semiconductor layer so as to fully melt the first areas, wherein the laser beams are irradiated onto the first areas, and the laser beams are not irradiated onto the second areas; and inducing the first areas to be laterally crystallized using the second areas as seeds.
[0010] In another embodiment, each of the prisms comprises a first slope and a second slope, which refract the irradiated laser beams in different directions.
[0011] In another embodiment, the first slopes may refract the irradiated laser beams at an angle from about 30° to about 40° clockwise from the incident directions of the irradiated laser beams.
[0012] In another embodiment, the second slopes may refract the irradiated laser beams at an angle from about 30° to about 40° counterclockwise from the incident directions of the irradiated laser beams.
[0013] In another embodiment, facing slopes of two adjacent prisms selected from the plurality of prisms may refract and transmit laser beams so that the laser beams overlap with one another in the first areas.
[0014] According to another embodiment, there is provided a method of manufacturing a TFT, the method comprising: forming a semiconductor layer on a substrate; irradiating a plurality of laser beams onto the semiconductor layer; splitting the laser beams using a prism sheet comprising an array of a plurality of prisms, advancing the laser beams toward the semiconductor layer to alternately form first and second areas in the semiconductor layer so as to fully melt the first areas, wherein the laser beams are irradiated onto the first areas, and the laser beams are not irradiated onto the second areas; inducing the first areas to be laterally crystallized using the second areas as seeds so as to form a channel area between the second areas; sequentially forming a gate insulating layer and a gate electrode on the channel area comprising at least two sides; and doping dopant ions into the second areas to form a source and a drain beside two sides of the channel area.
[0015] According to another embodiment, laser beams can be easily split using a prism sheet, and positions of areas of the semiconductor layer on which the laser beams are to be irradiated can be easily controlled in a laser annealing process for crystallizing the semiconductor layer. Thus, since it is very easy to control a position of a laterally crystallized area, semiconductor devices can be easily and uniformly manufactured. Specifically, if the laser annealing process is performed using the prism sheet, all of the laser beams can penetrate the semiconductor layer. Thus, the laser beams cannot be lost. As a result, use efficiency of the laser beams can be further improved in the laser annealing process for crystallizing the semiconductor layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
[0017] FIGS. 1A through 1C are cross-sectional views illustrating a method of manufacturing a laterally crystallized semiconductor layer according to an embodiment;
[0018] FIG. 2 is a scanning electron microscope (SEM) photograph illustrating an upper surface of the laterally crystallized semiconductor layer of FIG. 1C ;
[0019] FIG. 3 illustrates results of a simulation performed on differences between laser intensities of areas of the laterally crystallized semiconductor layer of FIG. 1B on which laser beams are irradiated and areas of the laterally crystallized semiconductor layer on which laser beams are not irradiated; and
[0020] FIGS. 4A through 4C are cross-sectional views illustrating a method of manufacturing a thin film transistor (TFT) according to an embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0021] A method of manufacturing a laterally crystallized semiconductor layer and a method of manufacturing a thin film transistor (TFT) using the method will now be described in detail with reference to the accompanying drawings. In the drawings, the thickness of the layers and regions is exaggerated for clarity.
[0022] It will be understood that when an element is referred to as being “on”, “beside”, or “above” another element, it can be directly on, beside, or above the other element, or intervening elements may be present therebetween.
[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
[0024] Unless otherwise defined, all terms (including 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. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0025] FIGS. 1A through 1C are cross-sectional views illustrating a method of manufacturing a laterally crystallized semiconductor layer according to an embodiment of the present invention. Referring to FIG. 1A , a semiconductor layer 12 is formed on a substrate 10 using a deposition method such as a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. The material for forming the semiconductor layer 12 is not limited. For example, the semiconductor layer 12 may be formed of silicon (Si), germanium (Ge), a compound of Si and Ge, or a group III-V semiconductor material. The semiconductor layer 12 may be formed in a crystal phase or an amorphous phase. The substrate 10 is not limited, and it may be a plastic substrate, a glass substrate, a quartz substrate, or the like.
[0026] Referring to FIGS. 1B and 1C , laser beams are irradiated on the semiconductor layer 12 . The irradiated laser beams are split using a prism sheet 110 comprising a plurality of prisms 102 , and advance toward the semiconductor layer 12 . First and second areas 12 a and 12 b are alternatively formed in the semiconductor layer 12 through the splitting of the laser beams to selectively fully melt the first areas 12 a. Here, the laser beams are irradiated onto the first areas 12 a but not irradiated onto the second areas 12 b. Lateral crystallization of the first areas 12 a is induced using the second areas 12 b as seeds to obtain a laterally crystallized area 12 c. The induction of the lateral crystallization will now be described in detail.
[0027] The first areas 12 a are fully melted but the second areas 12 b are not melted or less melted than the first areas 12 a in a laser annealing process. Thus, thermal gradients and solidification velocities of the first areas 12 a are different from those of the second area 12 b. Thus, nuclei are generated and grown at boundaries among the first and second areas 12 a and 12 b, and the solidification velocities of the second areas 12 b are faster than those of the first areas 12 a. Thus, a grain growth is directed from the boundaries among the first and second areas 12 a and 12 b toward centers of the first areas 12 a. As a result, the laterally crystallized area 12 c can be obtained.
[0028] Each of the first and second areas 12 a and 12 b may be formed to a width between 0.5 μm and 20 μm. The width is an appropriate numeral range for easily performing lateral crystallization. Reference characters A and B denote the first and second areas 12 a and 12 b, respectively.
[0029] The plurality of prisms 102 may be formed on a surface of an optical film 101 to manufacture the prism sheet 110 . The shape of the prism sheet 110 and the method of manufacturing the prism sheet 110 are well known in the art, and thus the prism sheet 110 can be easily manufactured. For example, the plurality of prisms 102 may be formed in a striped pattern. Each of the prisms of the plurality of prisms 102 may include first and second slopes, 102 a and 102 b respectively, which refract the irradiated laser beams in different directions. The first slopes 102 a refract the irradiated laser beams at an angle from about 30° to about 40° clockwise from the incident directions of the irradiated laser beams. The second slopes 102 b refract the irradiated laser beams at an angle from about 30° to about 40° counterclockwise from the incident directions of the irradiated laser beams. Thus, the laser beams are split.
[0030] The facing slopes of two adjacent prisms selected from the plurality of prisms 102 refract and transmit the laser beams so that the laser beams overlap with one another in the first areas 12 a. Thus, intensities of the laser beams irradiated onto the first areas 12 a can be increased. Specifically, the laser beams irradiated from the second slope 102 b of a first prism selected from the plurality of prisms 102 overlap with the laser beams irradiated from the first slope 102 a of a second prism adjacent to the first prism. Thus, the overlapped laser beams may be irradiated onto the first areas 12 a. Intensities of the laser beams irradiated on the first areas 12 a can be increased using the overlapping of the laser beams to shorten a time required for melting and laterally crystallizing the first areas 12 a.
[0031] The laser beams may be excimer laser beams or YAG laser beams. The excimer laser beams may be, for example, 308 nm xenon chloride (XeCl) laser beams. The semiconductor layer 12 has a high absorption coefficient with respect to these laser beams. If these laser beams are used, the semiconductor layer 12 may be easily heated.
[0032] The laser beams may be easily split using the prism sheet 110 , and positions of areas of the semiconductor layer 12 onto which laser beams are irradiated may be easily controlled in a laser annealing process of crystallizing the semiconductor layer 12 . Thus, since it is very easy to control a position of the laterally crystallized area 12 c, semiconductor devices can be easily and uniformly manufactured. Specifically, if a laser annealing process is performed using the prism sheet 110 , all of the laser beams may penetrate the semiconductor layer 12 . Thus, the laser beams are not lost. Therefore, use efficiency of the laser beams can be improved in the laser annealing process for crystallizing the semiconductor layer 12 when compared to the prior art. Also, since the prism sheet 110 is very low in cost, the cost for manufacturing a semiconductor device can be lowered according to the above method.
[0033] In addition, the laterally crystallized semiconductor layer 12 may be manufactured using a simple, easy process. Since the semiconductor layer 12 is formed in a lateral grain structure having a size of 1 μm or more, the semiconductor layer 12 has good electron mobility and good electrical characteristics. Thus, if a semiconductor device such as TFT is manufactured using the laterally crystallized semiconductor layer 12 , the performance of the semiconductor device can be more improved when compared to the prior art.
[0034] FIG. 2 is a scanning electron microscope (SEM) photograph illustrating an upper surface of the laterally crystallized semiconductor layer 12 of FIG. 1C .
[0035] FIG. 3 illustrates results of a simulation performed on differences between laser intensities of areas of the laterally crystallized semiconductor layer 12 of FIG. 1B onto which the laser beams are irradiated and areas of the laterally crystallized semiconductor layer onto which the laser beams are not irradiated.
[0036] FIGS. 4A through 4C are cross-sectional views illustrating a method of manufacturing a TFT according to an embodiment.
[0037] Processes of FIGS. 4A through 4C are similar to those illustrated in reference to FIGS. 1A through 1C , and thus their repeated descriptions will be omitted herein.
[0038] Referring to FIG. 4A , a gate insulating layer 22 and a gate electrode 24 are sequentially formed in the laterally crystallized area 12 c of FIG. 1C , which is referred to as a channel area in a process of manufacturing a TFT. The material and method for forming the gate insulating layer 22 are well known in the art, and thus their detailed descriptions will be omitted herein. The material and method for forming the gate electrode 24 are also well known, and thus their detailed descriptions will be omitted herein. For example, the gate insulating layer 22 may be formed of silicon dioxide (SiO 2 ) using a PVD or CVD method. The gate electrode 24 may also be formed of at least one material selected from the group consisting of nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), cobalt (Co), iridium (Ir), chromium (Cr), molybdenum (Mo), tungsten (W), rhodium (Rh), or the like, or a combination comprising at least one of the foregoing materials, using a PVD or CVD method.
[0039] Referring to FIGS. 4B and 4C , dopant ions are doped into the second areas 12 b positioned beside both sides of the channel area 12 c to form a source 12 s and a drain 12 d. The dopant ions may be selected from a conductive material group consisting of p-type dopants, n-type dopants, metal ions, and the like. An ion implantation method may be suitable as a method of doping the dopant ions but is not specifically limited. Specifically, the gate electrode 24 may be used as a mask in the ion implantation process, and thus an additional mask is not required. Thus, dopant ions may be easily selectively doped into the second areas 12 b, which are not covered with the gate electrode 25 , without the additional mask. An excimer laser annealing (ELA) or furnace annealing process may be additionally performed after the ion implantation process in order to activate dopant ions implanted into the source 12 and the drain 12 d. The ELA or furnace annealing process is well known in the art, and thus its detailed description will be omitted herein.
[0040] A laterally crystallized semiconductor layer can be manufactured using a simple, easy process. The laterally crystallized semiconductor layer can have a lateral grain structure having a size of about 1 μm or more and thus good electron mobility and good electrical characteristics. Thus, if a semiconductor device such as a TFT is manufactured using the laterally crystallized semiconductor layer, the performance of the semiconductor device can be further improved.
[0041] Also, laser beams can be easily split using a prism sheet, and positions of areas of the semiconductor layer onto which the laser beams are to be irradiated can be easily controlled in a laser annealing process for crystallizing the semiconductor layer. Thus, since it is relatively easy to control a position of a laterally crystallized area, semiconductor devices can be easily and uniformly manufactured. Specifically, if the laser annealing process is performed using the prism sheet, all of the laser beams can penetrate the semiconductor layer. Thus, the laser beams cannot be lost. As a result, use efficiency of the laser beams can be further improved in the laser annealing process for crystallizing the semiconductor layer. In addition, since the prism sheet is relatively low-priced, cost for manufacturing the semiconductor device can be lowered.
[0042] While the present invention has been specifically shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
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Provided are a method of manufacturing a laterally crystallized semiconductor layer and a method of manufacturing a thin film transistor (TFT) using the method. The method of manufacturing the laterally crystallized semiconductor layer comprises: forming a semiconductor layer on a substrate; irradiating laser beams on the semiconductor layer; splitting the laser beams using a prism sheet comprising an array of a plurality of prisms, advancing the laser beams toward the semiconductor layer to alternately form first and second areas in the semiconductor layer so as to fully melt the first areas, wherein the laser beams are irradiated onto the first areas, and the laser beams are not irradiated onto the second areas; and inducing the first areas to be laterally crystallized using the second areas as seeds.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the general method of portable monitors and diagnostic systems for life signs in living beings or operating efficiency in a dynamic system. The ability to detect life signs such as live heartbeat waveforms and body temperatures relates to the physical health of a living being. In an emergency situation where people are trapped or are residing in their homes, this ability to determine their life signs can translate into vital information to make decisions for rescuing people.
[0003] 2. Discussion of the Background
[0004] On the other hand, the vibration and temperature measurements in many dynamic systems can determine the health or reliability of the system. Such systems include motorized systems, engines, or even manufacturing equipment.
[0005] Vibrations produced by a beating heart generate heart sounds that, when detected by a stethoscope, can be electronically recorded by a phonocardiogram. The use of acoustic sensors permits the capture of the entire vibration spectrum. A vibration spectrum is a measurement of vibrating signal amplitude versus time. All vibration spectra can be transformed either in frequency or wavelet domains to improve the characterization of system dynamics, which can be correlated to actual physical phenomena, such as the closing of the heart values, the reverberation of the blood against the walls of the arteries, the valves in the veins, and the ventricular walls. When the vibrations of the vessels or ventricles come into contact with the chest wall, these vibrations can be detected as acoustic waves.
[0006] It is known that the phonocardiogram can be used to identify abnormal heart conditions, such as aortic stenosis, mitral regurgitation, aortic regurgitation, mitral stenosis, and patent ductus arteriosus. The transformed spectra give rise to unique peaks or pattern of peaks, allowing for quantifiable identifications and rules of computation to be performed.
[0007] The temperature of a person is very critical, especially in cold climates. The ability to correlate the person's heart rate against the body temperature gives a fuller picture of the severity of the situation.
[0008] This can be argued equally in the case of a vibrating system with motors, gears, bearings—it is known where the vibration frequency spectrum is characterized by many aspects of the system, including the motor rotation speed, the number of stators, and the bearings. Any changes in the vibration spectrum and temperature can suggest abnormality or premature failure.
[0009] In several occasions, it is necessary to have multiple channels for acoustic and temperature measurements; thus, the system requires an architecture that supports input expandability. A bidirectional wireless transmission capability allows the user to have freedom of movement for daily activities. The corresponding base unit can be in its vicinity. However, it would be too bulky for a field operation, so a field commander can wear a portable base unit in a pouch on the belt or pocket to become a relay station for an established network of existing communications. The existing network of communication can be in the form of Ethernet, USB, Internet, wireless IEEE802.11a/b/g or wireless IEEE802.16, etc. The network communication allows all the data to be stored, monitored, and further analyzed remotely. Since this is live data, monitoring the health and diagnostics in the field by experts in real-time becomes a reality.
SUMMARY OF THE INVENTION
[0010] In the prior art section, one of the following methods is used in the acoustic type of sensor design:
a) gel, b) adhesive, c) fluid, d) air, e) cavity, f) membrane, g) bonding sensor material to a structure,
[0018] where it is used for attachment to the user's body. When an adhesive is used to mount the sensor to the body, it can be quite a task to retrieve the sensor and realign the position of the sensor if it is placed wrongly and often not reusable. Furthermore, the use of gel is messy.
[0019] Acoustic sensors are particularly superior in providing a wide range of frequencies from sub Hertz to tenths of kilohertz. This edge has certain advantages over EKG or pulse oximetry IR sensors for the purpose of physiological process monitoring and diagnostics purposes.
[0020] Piezoelectric film materials are used in many acoustic sensors. These thin films are very delicate, non-elastic, but highly sensitive. The challenge to incorporate it in sensor design has always been its support and the coupling efficiency of the acoustic waves from the source to its film in generating electrical signals. The tearing of the film would be minimized when the force on its sides are equal; circular geometries are therefore preferred. When a film is bonded onto the edge of a hollow circular structure forming a diaphragm, the structure imposes a circular boundary condition restricting the kind of acoustic wave modes. Such structures would favor circular modes and diminish non-circular modes, similar to that for a drum. Since the heart's geometry and its associated pumping action are mainly non-circular, the acoustic signal efficiency is poor. The signal is further reduced when the coupling of acoustic waves to its surface is poor.
[0021] This invention uses an elongated piezoelectric film and embeds it within a silicone material with a shore-hardness in the range of 00-30 and 00-40 to overcome these two shortcomings. Furthermore, the length of the film is aligned to the axis of the heart to pick up the longitudinal wave modes. The silicone material also matches the impedance. A piece of non-stretchable woven fabric is also embedded into the silicone as shown in FIGS. 6 and 7 . The fabric has two roles. It supports the entire film and the silicone and it provides an orthogonal surface pressure for the silicone to be firmly pressed onto the chest with or without a thin undershirt. These sensors can therefore be Velcro attached or embedded to a well-fitted undershirt or even a brazier. The placement of sensors on the chest instead of hands or fingers will allow the user to perform daily activities with their hands or even during exercises. Oximetry sensors cannot be used on the chest. On the other hand acoustic sensors can be used on the arm wrists and also the neck for detection of heart pulses.
[0022] Another property of acoustic piezoelectric film sensors is the large variation in signal amplitudes, not found in EKG and oximetry sensors. EKG electrodes rely primarily on electrical contact, thus output voltages are usually in the order of millivolts. The designs for EKG monitoring systems are inadequate for handling acoustic sensing devices, since their digital signal resolution over a wide amplitude range is poor. The present invention overcomes this limitation with a programmable gain amplifier (PGA) on its front end. This amplifier ensures the maximum signal amplitude is presented across the analog to digital converter for maximum digital resolution. In addition, the architecture to support the PGA is based on the serial peripheral interface (SPI) bus; multiple acoustic sensors can be attached as shown in FIG. 3 .
[0023] On the other hand, oximetry measurements require both infrared LEDs and detectors for heartbeat measurements. Intensity feedback-adjusted power-controlled LEDs provide the optimized detector with compensation to the detection average signal voltage, improving its signal to noise ratio. The present architecture also supports this kind of sensor as the feedback is through a digital to analog converter (D/A) with the SPI bus. These sensors are suitable for finger mounting.
[0024] This architecture also supports user communication with base unit selectivity. The base unit has the ability to select among remote systems. This is important in identifying and selecting the remote unit to allow the usage of two or more units in the same vicinity. This selectivity is based on two identifiers, a channel code and a user identification code, which are illustrated in FIG. 13 . The channel code is the hardware allocation and the user ID is the software allocation. When the remote unit has the same channel as its base unit, both are periodically active waiting for instructions from the base unit. Only when the base unit sends a matching ID will it respond with a transfer of data. Different base units with different channels can operate at the same time without interference. At any single moment within its RF signal range, it is possible to communicate with the maximum number of separate channels less one for the base unit can have. There will always be one default channel. The base unit will always start on the default channel before switching to a free channel. The default channel is reserved for communications setup between remote units and base stations. This is a very flexible architecture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 . Architecture of the Life Sign Active Monitoring and Diagnostic System
[0026] FIG. 2 . The WEM unit with motherboard and daughter board and the various connectors
[0027] FIG. 3 . WEM motherboard internal block diagram
[0028] FIG. 4 . Daisy chain programmable gain amplifiers
[0029] FIG. 3 . One-wire multi-drop or chaining of several temperature sensing devices.
[0030] FIG. 6 . Acoustic Polymeric film with two electrodes printed with silver ink.
[0031] FIG. 7 . Acoustic Sensor with elastomeric support and flap
[0032] FIG. 8 . Holes in the acoustic sensor flap support for integrity
[0033] FIG. 9A . Semicircular rigid support for the acoustic sensor with its flap wraps around the curvature.
[0034] FIG. 9B . FIG. 9 b illustrates a cross section of the assembly of FIG. 9 .
[0035] FIG. 10 . One-wire DI bus Reset and Presence pulse
[0036] FIG. 11 . Write and Read Time Slots for the One-Wire Body Temperature Devices
[0037] FIG. 12 a . ZigBee hardware setup between microcontroller and the RF transceiver.
[0038] FIG. 12 b . An modified Zigbee solution with External flash memory and/or EEPROM device
[0039] FIG. 13 . Remote and Base Units communication network
[0040] FIG. 14 . System with Analog voltage out modification to motherboard
[0041] FIG. 15 . Position alignment of acoustic heart beat sensor to the physiology of a person
[0042] FIG. 16 . Actual Acoustic heartbeat sensor measurement.
[0043] FIG. 17 . An example of a Fast Fourier Transform results of a human heart waveform.
[0044] FIG. 18 . An example of a wearable life signs monitoring and diagnostic vest featuring use of conducting fabric to integrate electronics to antenna, sensors and power sources.
[0045] FIG. 19 . A flowchart showing process of automatic patient ID identification recognition and a secure database data collection.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] This detailed description of the preferred embodiments serves as a guideline on how it can be implemented in a preferred manner. It illustrates the concept and does not limit the scope of the invention. However, the organization, operation, advantages and objects of the invention can be more fully appreciated from the following description.
[0047] 1) System Components
[0000] This invention involves the use of certain block elements, and FIG. 1 summarizes their relationship:
[0000]
a) Wearable Electronic Module (WEM) powered by its battery supply or through its communications port
b) Analog Sensor/s (Acoustic)
c) Digital Sensor/s (Body Temperature)
d) Embedded Antenna (Flexible Printed Antenna)
e) Wireless Network, Wireless Channels, Computer System
f) Waveform and Spectra Analysis
[0054] The core of the system is the WEM unit, which is shown as the blocks within the dotted box in FIG. 1 . The design is based on nanoWatt technology and active components such as microcontrollers; transceivers have standby and/or power down modes to extend battery life. This is a multifunctional module that can be used in different methods for several locations in a large-scale system. The basic functionality of each of its ports is described below, and the ways it can be deployed in different roles in the overall system is described in the next section.
[0055] The motherboard of this module has two types of ports, Analog and Digital. The Analog port, represented by the letter ‘A’, receives analog signals and also provides power to the analog device such as an acoustic sensor and samples the data on demand. On the other hand, the digital port and Digital input data, represented by the letter ‘D’, provides digital communication protocols, such as the ‘One Wire’ standard, to its digital devices, such as body temperature sensors. The One-Wire protocol is used to reduce the number of data lines occupied by the sensor network.
[0056] This motherboard has a bidirectional serial communication port, allowing it to connect directly to the serial RS232 port or a USB port of a computer. The bidirectional communication capability permits it to receive instructions and to send data to the computer. In the USB configuration, it is even possible to draw power from the computer, eliminating the requirement of a battery pack.
[0057] The flexibility of this motherboard stems from the use of both jumpers and switches to reconfigure its hardware interface with the RF transceiver and the serial communication transceivers. On the other hand the daughterboard allows interface with motherboard for software programming.
[0058] Each WEM has RF transceivers on board, so communication with another WEM is possible. This allows the WEM to communicate with the remote computer system.
[0059] 2) Wearable Electronic Module (WEM)
[0000] The WEM is an electronic module that performs the following functions (See FIG. 2 ):
[0000]
a) Data acquisition—Input data acquisition in real time comes in two forms, analog and digital. Analog data acquisition is sent first to a front-end programmable gain amplifier (PGA), U5 as shown in FIG. 3 . The digital data acquisition is performed using a one-wire protocol. This protocol reduces the number of interface lines to two with an optional third line for power.
[0061] In particular, we are referring to the acoustic sensor as the analog sensor and the body temperature sensor as the digital sensor.
b) Analog signal acquisition—The analog data acquisition may use of four lines to interface with the microcontroller—a voltage output line and three Serial Peripheral Interface (SPI) lines apart from the two positive and negative power supply lines. An optional external voltage reference line is used if the reference voltage is chosen to be a variable. Otherwise a fixed reference voltage is assigned.
[0063] The analog sensor output is connected to one of the two selectable channels of the PGA. The PGA is a selectable gain to its single-ended, rail-to-rail input/output operational amplifier. This gain selection allows the actual sensor signal dynamic range to be captured within its maximum bit resolution achieved by the analog to digital input port, U6-P1. A PGA example is Microchip PGA series MCP6S91/2/3. This chip controls its gain through three SPI interface lines, namely, SPI Chip Select (CS), SPI Clock Input (SCK), and SPI Serial Data Input. These interface lines are connected to U6-P11, U6-P12 and U6-P13 respectively on the microcontroller side.
[0064] The chip, MCP6S92, has two analog channels selected by an internal MUX and therefore up to two analog sensors can be used. If more analog sensors are needed, the data acquisition design can be expanded by daisy chaining the MCP6S93 as shown in FIG. 4 with each additional chip with two more sensors input. In contrast to MCP6S92, MCP6S93 has an additional SPI interface line, SPI serial Data Output, SO. The SO interface line is connected to the second device in line MCP6S93 SI interface line.
[0065] The digital resolution for most microcontrollers is either 10 bits or 12 bits. At a maximum of 3.3 volts, a 10-bit resolution gives approximately a +/−3.3 mV error. Therefore it is preferred to keep the input voltage presented to the A/D converter close to this maximum voltage to give a good resolution. This is the primary PGA function.
[0066] Sampling Rate:
[0067] Sampling rate is important for accuracy of capturing the waveform. According to the Nyquist criteria, the sampling frequency must be at least twice the frequency of the highest signal frequency component. For example, if the sampling time were 50 milliseconds, which is 20 Hz, then the highest frequency component captured would be 10 Hz. A normal person's heart rate is 60 beats per minute or one beat per second. Thus, a 20 Hz sampling rate is sufficient for a human heartbeat. However, for diagnostic purposes, much higher frequencies may be preferred, and this means sampling times should decrease. This sampling rate also affects the baud rate chosen if live data is to be collected.
c) Digital signal acquisition—The digital acquisition using the one-wire protocol uses only a data line (DI) and ground. Depending on the digital device it interfaces, a positive power line (VCC) may be required. The DI line from the digital sensor is connected to a digital signal pin input, U6-P14 on the microcontroller.
[0069] Another advantage of the one wire protocol is to have a chain on the number of digital temperature sensors on the same DI line as shown in FIG. 5 . Each sensor has a unique identification code (ID). The DI line is connected to the DQ pin of each device. It first identifies the identification code and then activates the sensor to be active. Then the sensor reports its value to the ID.
[0070] The one-wire protocol is bidirectional and the device pin actually floats to give high impedance so that the active device controls the DI line. It is this property that provides the multi-drop or “chaining” capability to hundreds of devices on a single DI line. However, the one-wire signaling scheme is preferred for all its communications. This signaling scheme is described in more detail in the body temperature device section.
[0071] A one-wire device such device may be a Maxim DS1991 in a microcan package, which contains a guaranteed unique 48 bit factory set serial number with 1,152 bit read/write non-volatile memory. This provides the patient or user with a guaranteed unique patient identification tag, and this device stays permanently with the patient. When the vest is put onto the user, a flexible circuit with two conductors (conductive thread, or conductive printed thick film) is then connected to the DI line and ground line of the microcan (DS1991) as one of the one-wire devices shown in FIG. 5 (with microcan top being the I/O line and Gnd the bottom part of the microcan). This unique ID will be retrieved by the one-wire measurement protocol whenever life signs data. This retrieved unique ID will in turn direct the storage of the data record into the specific patient file folder in the database avoiding error in the data collection record process. This process flowchart is shown in FIG. 19 .
d) Daughter board (microcontroller system with unique ID)—The use of the daughter board with all the microcontroller functions and clock on board is a flexible design. This allows the other portion of the board essentially unchanged while the daughter board can be programmed, upgraded or changed.
[0073] On the other hand, the architecture is flexible as it can that can be programmed from a daughter board which controls the data sampling rate and sequence on demand from its source via either its direct serial RS232 communication port or via the bidirectional RF transceiver port. It responds to the request by relaying the requested data back to its source with a preset baud rate.
[0074] The daughter board contains a microcontroller, a crystal clock or a resonator and an EEPROM. The EEPROM can be used to store a unique identification code. This code is used for identifying which daughterboard is used and its functionality. A good solution is to use the flash programmable Microchip microcontroller, PIC18F4550 (44QFN) or PIC18F2550 (SOIC-28), which has the USB2.0 communication protocol capability (12 Mbps) with 1024 bytes of USB buffer and internal 8 MHz oscillator. In addition, it has EUSART capability for the RS232 communication with both line transceivers and RF transceivers. The fast USB communication is for direct connection with the computer. The SPI communication capability is used for controlling the SPI interfaced PGAs. This microcontroller is ideal for the high-end performance of WEM, where it has to communicate with multiple WEMs. Furthermore, it has 36 I/O pins, 32768 bytes of program memory, 2048 bytes of RAM and 256 bytes of EEPROM memory and capable of supporting 48 MHz clock. This high clock speed and memory is necessary for both USB and the many tasks it has to perform.
[0075] Microchip microcontrollers, PIC16F688S/L or PIC16F690S/L are candidates for this application, operating at 3.3V common to U1 and U2, U4 and U5. The PIC16F688S/L comes in SOIC-14 package has 12 I/O and 8 A/D channels. On the other hand, PIC16F690S/L comes in SOIC-20 package, has up to 18 I/O lines and 12 channels 10-bit A/D. Both have EUSART for RS232 protocol, 4096 words of program memory, 256 bytes SRAM and 256 bytes of EEPROM. In FIG. 3 , the daughter board includes 13 digital I/O ports and one A/D port giving a total 14 Pins. In addition, there are Vcc Pin and Gnd Pin, Reset and Programming shares one Pin (MCLR/Vpp), Clock In Pin and Clock Out Pin.
[0076] Since PIC16F688S/L has only 14 pins total, it still can be used if physical jumpers were to be used instead of electronic switching which eliminates four pins, P2 to P5. In addition Pin P10 can be eliminated by replacing it with a permanent enable line to U1. The jumper implementation has been demonstrated that the PIC16F688S/L microcontroller has adequate functions to perform the basic functions.
[0077] Although these two microcontrollers do not have hardware SPI built in function ports, software driven SPI communications are common, and they rely on the simulated clock with all the edges defined and synchronized. Alternatively, simple operational amplifiers such as National Semiconductor, LMC6036, can replace the SPI driven PGA with different feedback resistors shunted by CMOS transistors for gain selection.
[0078] Both chips have an internal 8 MHz clock. Should it be used instead of an external clock source, both Clock In and Clock Out will not be occupied, freeing two I/O lines.
[0079] Other manufacturers' microcontrollers can also be used as the preceding only illustrates the design requirements.
Switch/Jumper block—The basic function of the Switch/jumper block is to achieve the following communications: i) U1-Tx and U1-Rx to select its bidirectional communication with U2-Tx and U2-Rx. This enables the RF transceiver to communicate directly with the computer connected to the RS232 serial port. ii) U6-P4 and U6-P5 to select its bidirectional communication with the U1-Rx and U1-Tx of the RF Transceiver, U1. This is use in the remote unit in communication with a system connected to a computer. iii) U6-P4 and U6-P5 to select its bi-directional communication with the wired RS232 Serial Port, U2-Tx and U2-Rx. This is for the microcontroller communicating with the computer. iv) Idle state without Communication and the system is powered down.
The control lines on the daughterboard, U6-P2 and U6-P3 control the communication used in switch/jumper, U4. This simply allows the switches/jumpers hardware to reconfigure the source of communication to its destination. In the case of jumpers, six lines are used instead of four.
Cases i) and ii) are the two most basic communication modes and therefore can even be implemented with the use of physical switches or jumpers. However, for flexibility, electronic switching is preferred. e) Serial Communications—The WEM serial communications functionality allows the WEM to communicate with the computer system, communicate with other WEMs in a direct line serial mode or a remote RF communication. The various serial communications mode are USB, direct line RS232 and RF communication. The USB to computer communication is already discussed in section d. f) Direct line Serial Communication—The direct serial communication block allows the WEM to communicate bi-directionally with a computer system. It uses the Maxim chip, Max3225EEAP RS232 Transceiver, which has two sets of transmit and receive transceivers with an auto shutdown capability. This chip is ideal for U2 in the block diagram as shown in FIG. 3 . The chipset can achieve a baud rate up to 1 Mbps and it has its internal dual charge pump using only a single voltage supply. However, the baud rate is normally limited by the baud rate achieved by the daughter board. In this case, it can communicate from 19200 baud to 115 kbaud. It is recommended that the system should not go lower than the 19200 baud rate. g) Remote RF Serial Communication—The Abacom AT-XTR-903-A9 RF Transceiver chip operates in the carrier frequency range from 902-928 MHz does not interfere with the IEEE802.11 g 2.4 GHz wireless network devices is ideal in such an environment. Furthermore, it has 169 selectable operating channels and three selectable input serial data speed (9600, 19200, 38400 bits/sec) via U6-P7 and U6-P8. U6-P9 control line can power down this chip to reduce power consumption. At 9600 baud, it performs both Hamming and Manchester encoding. At 19200 baud rate, it performs only Manchester coding. Finally at 38400 baud, it performs Scrambling. The highest level of data integrity is at 9600 baud, which allows correction of any single error occurring in any data nibble.
[0090] Channel selection is carried out by sending specific AT commands to the U1-Tx input. Channel “0” is the default channel. First the chip has to enter into command mode before the AT commands can be issued. These commands either read or write to its 16 available registers. After the correct command is issued, it can assign a certain frequency of operation. These register values can be saved into the EEPROM memory, which will not be lost when module is powered down. Once an exit command is issued the chip returns to its normal operation and data can be transmitted.
[0091] In power down state it switches all active circuitry consuming only ˜10 μA of current through the use of the U2-PDN2 pin.
[0092] In addition, this chip provides Received Strength Signal Indicator (RSSI) with its value ranging from 0 through 9 where “0” is minimum field strength and “9” is maximum field strength.
h) Digital to Analog—In some measurements such as oximetry, additional analog control is needed. An example is driving the infrared LEDs and detectors for heartbeat measurements. This allows a feedback to adjust voltage to controlled LED intensity to optimized average signal voltage from the detector, thereby improving its signal to noise ratio. Microchip MCP4921/2 are digital to analog converters (D/A) with the SPI bus controls and they can be used as U7 as shown in FIG. 14 . The I/O pins 15 , 16 and 17 are SPI bus controls, allowing the microcontroller to send digital codes to set up the analog voltage. MCP4922 itself has two D/As. If more than two D/As are required, then I/O pin P18 is used for driving the LDAC signal pin, which synchronizes when the serial settings are latched into the DAC's output. Additional chip select is required and an I/O pin P19 (not shown) will be used. i) Voltage Regulation—The WEM is supported by battery and it also indirectly provides power to the sensors. In the system illustrated here, 3.3 volts is used. Therefore, 3.3V Low Drop Voltage regulators are used to regulate the power supply to the chips U1, U2, U4, U5 and U6. The 3.3V Texas Instruments LDO chip TLV2217-33KTPR is used for U3. j) Spectrum Analysis—The data obtained by the computer through the base unit will allow a time domain waveform to be plotted. Spectral analysis of this waveform requires either Fast Fourier Transform or Wavelet Transform performed on them.
[0096] 3) Acoustic Sensors
[0097] The Acoustic sensor is able to pick up acoustic waves from the heart vibration. This sensor is based on an acoustic sensing film made of PVDF. The film produces a voltage and is captured on the two silver electrodes printed on the opposite faces of the polarized homopolymer of vinylidene fluoride PVDF material as shown in FIG. 6 . These electrodes are riveted to a wire or conductive epoxy attached to the sensor connector. The film is given the freedom to flex.
[0098] The film itself is too sensitive and is enclosed in an elastomeric material, such as silicone or urethane plastic, which comes in the form of two parts liquid, A and B. By mixing part B to part A in a mold, an elastomeric structure in the form of the mold is created. It is recommended to use a shore hardness silicone or urethane in the range 00-30 to 00-40, which is soft like the flesh. At this range, the acoustic impedance between the flesh and the urethane or silicone is matched. This will reduce acoustic reflection and allows the acoustic waves to travel to the film sensor without much energy loss. This softness also allows the sensor to contour the curvature of the chest to leave no air gaps.
[0099] There are several steps to this molding of urethane plastic, which is shown in FIG. 7 . First a thick layer of the urethane is created on a rectangular mold as layer 1 . Layer 1 slab thickness preferably is greater than layer 3 slab thickness. Then before the curing of the plastic is complete, the film sensor is placed within centered within the flat surface. Then another layer of silicone or urethane plastic is poured. This time it is to bind the film sensor tightly to the mold. Let this second mold layer cure. Before the curing is complete, place the sensor flap sheet made of a highly flexible but non stretchable fabric, 4 , with the holes as shown in FIG. 8 on the curing silicone or urethane and prevent air bubbles from being trapped. These holes allow the next layer of silicone or urethane pour to bind well to the layer of silicone urethane below the flap. This fourth layer labeled 5 completes the acoustic sensor structure.
[0100] The acoustic sensor needs a perpendicular pressure against the body for it to pick up the heartbeat waveform from the chest. This is achieved with a semicircular structure shown in FIG. 9 . The pressure is to be applied in the X direction. The Y-Z axes define the plane in which the sensor is to rest on the chest or skin. The flap wraps around the semi circular surface and joined by an elastic sheet. The flap has a freedom to slide on this semi circular surface. Therefore the pressure on the film in the x direction is ensured when the pressure is applied to the chest in the negative x direction. This architectural design also eliminates the vibrations in the Y-Z plane.
[0101] FIG. 9 b illustrates a cross section of the assembly shown in perspective in FIG. 9 a . Item 104 illustrates the sensor assembly of FIG. 7 . As shown in FIG. 7 , the sensor assembly includes stretches of fabric 101 that extend beyond the periphery of the polymer. Additional pieces of elastic material 102 a , 102 b are sewn to or otherwise attached to the fabric extensions 101 . The elastic material wraps around curved rigid member 105 (also shown as item 4 of FIG. 9 a ) to a region of overlap 103 . The pieces of elastic material 102 a , 102 b are fastened together at region of overlap 103 by sewing, Velcro™ or other means.
[0102] The alignment in placing the sensor is shown in FIG. 15 . A typical acoustic sensor heart beat waveform measured is shown in FIG. 16 . The corresponding vagal tone can be extracted from the heartbeat waveform data.
[0103] It should be noted that this technology can be applied to other parts of the body just as effectively or better. Arm wrists and neck are particularly good places for detecting heartbeat waveforms too. The sensor can be applied to the abdomen of pregnant women to detect fetus heartbeat waveform and also its vagal tone.
[0104] 4) Body Temperature Sensor—This sensor is a one-wire protocol sensor. This sensor can be from a family of temperature sensors such as Maxim DS18S20, DS18B20, DS1822, and DS2422. These are on-wire protocol devices, which can be chained together as shown in FIG. 5 . Each of these devices has an identification code, which allows the data received on the DI bus being distinguished.
[0105] The following is a description how each of these devices communicates with the microcontroller through the DI bus. It is recommended for the clock on the Microchip microcontroller be set at a minimum of 8 MHz since it takes 4 clock cycles per instruction. All communications are achieved through the use of “Time slots”, which allow data to be transmitted over the DI line. Therefore it is preferred that the microcontroller I/O port connected to the DI bus have three digital states, namely, “high”, “low” and “float”. The “float” state occurs when the microcontroller I/O port transform into a high impedance state, which allows the devices on the DI bus to control the line. Each communication cycle begins with a reset pulse initiated by the microcontroller pulling low on the DI line for a minimum of 480 microseconds as shown in FIG. 10 . At the end of the reset pulse the DI line is pulled up high for duration between 15 and 60 microseconds by the pull-up resistor, R, shown in FIG. 5 . A device presence pulse signified by pulling low the DI line by the device with duration between 60 and 240 microseconds after reset.
[0106] Both writing and reading to the device requires the use of a write and time slots respectively as shown in FIG. 11 . In writing, the microcontroller pulls DI bus from logic high (inactive) to logic low state. The write slots duration must stay be within 60 μs to 120 μs with a 1 ms minimum recovery time between cycles. The microcontroller pulls the DI bus low for the duration of the time slot during the write “0”. However, for the write “1” time slot, the microcontroller first pulls the bus low and then releases the line within 15 μs after the start of the time slot.
[0107] In the case of reading the device by the microcontroller, a read time slot is first initiated by the microcontroller pulling the DI bus low for 1 μs then releases it so that the DS18×20/DS1822 device can take control of the DI bus, presenting the bus with valid data (high or low). Again all read time slots must stay within the 60 μs to 120 μs duration with a minimum 1 μs recovery time between cycles. The device has to respond within the read and write time slots for the data to be read or written.
[0108] The identification of the device begins with the typical initialization sequence of a Reset by the microcontroller. Then the slave devices respond by issuing simultaneous presence pulses. Since each slave device identification code is unique, the microcontroller issues the Search ROM command on the DI bus. This identification code can be used to identify the location of the sensor on the body. The following is the description of ROM search process.
i) Each device will respond to the Search ROM command by placing the value of the first bit of their respective ROM codes onto the DI bus. The microcontroller then read the bus value. When there is one or more devices with their first ROM code value “0”, it will cause the bus to go pull low. Those devices with 1 's for their first ROM code do not affect the bus if it was already pulled low by any one device, whose first ROM is a “0”. This is because these can only draw current from the resistor, R, and pull down the bus voltage. This is essentially a logical AND operation for all devices on the bus. The microcontroller will read low if any of the first ROM code value is “0”. ii) All the devices on the DI bus will respond to this read by placing the complement of their first bit of their ROM codes onto the DI bus. The consequence of this action by those devices whose first ROM code is “0” and changing them to a “1” will allow the DI bus to stay high. iii) At this time the microcontroller has to deselect those devices with ROM code “1” by pulling the DI bus low or equivalent to writing a value “0” on the DI bus. This action will allow only those devices with the first ROM code “0” to remain connected to the DI bus. iv) The microcontroller performs a second ROM code from the devices. The devices with the second ROM code “0” will first pull the DI bus low and then switch to its complement value to allow the DI bus to stay high. Whereas those devices with the second ROM code “1” do not need to switch to its complement value. This means that each time the DI bus senses a switch from “0” to “1” change, there must be at least one device with a ROM code “0” for that code position. Again by pulling the DI low deselect those devices with second ROM code “1”. v) By the process of de selection, the microcontroller will finally able to select only one device and read its ROM code successfully. vi) Then by repeating this process each of the devices on the DI bus will be identified.
[0115] vii) The microcontroller learns the unique ROM code of each device during each ROM search pass. The time required to learn one ROM code is:
960 μs+(8+3×64) 61 μs=13.16 ms
This means it can identify up to 75 devices on the same DI bus per second.
[0117] The reading of the temperature involves selecting the device by the Match ROM function first. This is achieved by sending a reset. If reset is true, return false. Then send a Match ROM command (0×55) followed by another send command with the ROM code. This will avoid data collisions with other devices on the same DI bus.
[0118] If this returns true then send reset followed by a write skip ROM command and then a start temperature conversion command. Next send another skip ROM command and then a Read Scratch Pad command. The temperature value is stored in the scratch pad.
[0119] 5) Embedded Antenna (Flexible Printed Antenna)
[0120] Both remote unit and base unit use antennas for transmission. In the case of a 900 MHz transmission design, antennas can be part of the wearable fabric and a length approximately 16.5 cm or half its wavelength using the formula:
Length L =λ/2=Speed of Light, c /(2×Frequency of Transmission) (1)
[0121] The antennas tested were printed with conductive Polymer Thick Film (PTF) Ink first and then followed by a flexible insulating dielectric to cover the traces, except where the connections are on the non-stretchable woven fabric made of polyester or nylon. The PTF inks typically are cured at 125 degrees Celsius. Since the fabric is woven, the antenna is quite rugged, highly flexible, and soft to the touch. For the purpose of aesthetic value, the printed side can be on the inside. However, the body, with high water content, tends to be a ground plane. It is recommended to have another fabric material spaced between the antenna and the skin.
[0122] The antenna connection can be formed by using snapped on buttons directly snapped on to the cured conductive ink with conductive epoxy on button's back to secure it. Protective insulating coating should be applied to any exposed epoxy or conductive traces to prevent issues like silver migration when the antenna is in contact with water.
[0123] 6) Wireless Network, Wireless Channels and Computer System
[0124] As mentioned earlier, this wireless network architecture supports users with a remote unit to communicate a base unit. It is the base unit that selects the channel the remote unit to operate in. A base unit has the ability to communicate with more than one remote unit. Each unit has a unique identification including the base unit. The base unit distinguishes itself from the remote unit from the daughter boards program and the switch or jumper setting. Once the unit is established remote or base, the overall system would be controlled by an external computer communicating with the base either through a USB, or RS232 serial port. If the base is connected to an embedded system that links USB to a wireless port for IEEE802.11a/b/g WiFi communication network; this computer can be in a remote location. An alternative is to incorporate the 802.11a/b/g universal wireless LAN chipset, Atheros AR5112. This increases the complexity, power consumption and cost on the unit. A simpler solution would be to use an embedded device could be achieved using GumStix's solution, which is based on the Intel PXA255 processor, roughly the processing speed of 233 MHz, AMD K6 processor.
[0125] In FIG. 13 , multiple remote units and base units are in their own wireless network. It is important for the base unit to identify and select the correct remote unit, since there can be more than one remote unit within the wireless network range. This selectivity is based on two identifiers: a channel code and a user identification code. A channel code defines a physical channel such as “A” or “B”, which can be two separate frequencies channels and therefore a hardware allocation. The user ID is on the other hand a software allocation and it is a code in the EEPROM.
[0126] The base unit will always start with the default channel and then look for a free channel to switch into. No two base units within the wireless range should have the same channel other than the start up period with the default channel. The base units will start with a receiver mode and scan for any base units. If there is a similar base unit it will inform which channel that unit is operating at. After the scan it will establish all base unit frequencies of operation. It will check also counter check with the database, which channels are used and which remote units are there.
[0127] When a new remote unit is introduced into the network, it will start to communicate with it at the default channel first to inform it which new channel it should switch to. After handshake is complete, both remote and base unit will change to the new channel. When the remote unit has the same channel as its base unit, it will stay periodically active waiting for instructions from the base unit. Only when the base unit sent the ID is identical to the remote unit, that unit will respond with a transfer of data.
[0128] The database of remote units accessed by a base unit can support several remote units on the same channel. This base unit will communicate with those units as well. Different base units with different channels can operate simultaneously without interference. At any single moment within its RF signal range, it is possible to communicate with one less than the maximum number of separate channels. There will always be one default channel reserved. During shutdown, all units return themselves to the default channel. This channel assignment process can be seen as dynamic. This is a very flexible architecture.
[0000] Other RF Protocols:
[0129] Another RF protocol available for this application is ZigBee, which operates at 20 kbps with transceivers frequency at 900 MHz to 250 kbps with transceivers frequency at 2.4 GHz. ZigBee supports the IEEE802.15.4 standard transceivers. The Zigbee technology allows thousands of devices (routers and end devices) to be connected in the network with unique MAC addresses and network addresses. This allows many vests to operate in the same vicinity. The Zigbee hardware setup uses a microcontroller with SPI bus and some control lines to the RF transceiver as shown in FIG. 12 a . This is a fully acknowledged protocol and supports low latency devices and its range is between 30 and 300 feet. It can also operate in both secured and unsecured mode with an optional 128 bit AES encryption. An example of such a 2.4 GHz transceiver is Chipcon CC2420 in a 48 pin QLP package and it operates at 3.3V with 16 channels. Other examples of a 2.4 GHz transceiver chip is Ember EM250 and EM260. The EM250 is a single chip solution with both microcontroller and RF transceiver built in. There is limited code space available in its flash memory. A preferred solution is to use an EM260 where it replaces the RF transceiver, U1, as shown in FIG. 14 , to add EEPROM or Flash memory devices to the SPI bus for buffer storage of real-time data prior to transmission, and to add program memory space as shown in FIG. 12 b . The Chipcon chip CC2431 has a hardware solution for providing location based signal strength on triangulation with its routers' location. Such location tracking can provide mobile data on a moving patient while lifesigns are being monitored. A similar approach can be implemented on the EM250, EM260, Abacom AT-XTR-903-A9 (900 MHz) transceiver by using the RSSI (Receive Signal Strength Indicator) values as approximate distance measurements from the fixed or known location devices it communicates with. The EM250, EM260 and CC2431 RF transceivers are designed to coexist with other 2.4 GHz products running the EEEE802.11 protocols. For example, CC2420, uses the following input/output (I/O) connections to the microcontroller:
[0130] i) FIFO,
[0131] ii) FIFOP,
[0132] iii) CCA,
[0133] iv) SFD,
[0134] v) CSN,
[0135] vi) SPI Clock (SCK),
[0136] vi) Serial Data In (SI),
[0137] vii) Serial Data Out (SO),
[0138] viii) Reset,
[0139] ix) Vreg_en,
[0140] There are other IEEE802.15.4 compliant RF transceivers that will operate at 915 MHz ISM with 40 kbps and 10 channels. The microcontroller, PIC18F4550, discussed in daughter's board section has 32 Mb memory, SPI bus and computational speed to run the ZigBee stack. Other possible wireless communication protocol is Bluetooth. The above examples show how the system can use the different protocols but not as a limitation.
[0141] 7) Waveform and Spectra Analysis
[0142] The periodic sampling of the signal for the analog sensors such as acoustic sensor is a performed only for a given total number of samples. In the Fast Fourier Transform (FFT) algorithm, it is necessary to select a number of samples given by the formula:
No of samples required=2ˆ (2)
where ˆ is to the power of,
[0143] n is an integer.
[0000] for a complete set of input required to perform the FFT.
[0144] 256, 512 and 1024 samples are legitimate set of sample points. If the sampling rate is 50 milliseconds, they take 12.8, 25.6 and 51.2 seconds respectively to collect a full set. This is an acceptable time frame for a common application.
[0145] The FFT gives a set of coefficients for each corresponding discrete frequency. FIG. 17 shows a plot of the human heart beat waveform in time domain (top trace) and a corresponding frequency domain (bottom trace). There are several noticeable peaks and the second peak from the left (corresponding to discrete frequency Number 11) is the regular dominant heart beat rate of 78. The largest peak at zero frequency is the dc level of the signal and can be eliminated. There are certain rules that can be used to detect the heart rate and the heartbeat waveform for diagnosis.
[0146] If a set of heart beat waveforms is documented as normal for a particular person, the relative FFT coefficients can be treated as a good reference. Relative coefficients would be the normalized set as shown in equation 3. This set should be collected for when the person is fully rested to under stress, like walking and running on a treadmill. An example would be to collect five sets of readings for each range of dominant heart beat rate. Assume there are ten sets on dominant heart rate. Each of the relative dynamic set of frequency coefficients, F r (m), is expressed as a function of a given heart beat rate, r.
Σ F r ( m )=1 (3)
where m=n/2, numerically equals to half the value of sampling points.
[0147] A polynomial function, φ m (r), is fitted that for each m value, it gives the interpolated value for the anticipated normalized m th Fourier coefficient for the heartbeat rate, r (shown in equation 4). This gives the pattern on how the normalized coefficients would change with the dominant heart beat rate, r. Notice that there is no case where r=0, since it means the heart is not beating and r max is probably no more than 200. Assume r1 is the minimum heart beat rate, and rk is the maximum heart beat rate, then
φ m ( r )= A ( r ) F r1 ( m )+ A ( r ) F r2 ( m ) . . . + A ( r ) F rk (m) (4)
This formulation will produce a known good set of waveform coefficients for the database on that particular subject.
[0148] When a new reading is taken on the same subject, it is now possible to use the actual readings and compare its new coefficients to that predicted by the equation (4) given the measured heart beat rate. If the sum of set of coefficients exceed a given percentage or any individual coefficient exceeds a given percentage, then it can be used for an alert.
[0149] Similarly, this can be performed for wavelet transform coefficients. Only the basis sets and functions are very different.
[0150] This is a methodology on how to analyze the heartbeat waveform for the purpose of monitoring and diagnostics.
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A system and method that uses a non-invasive method, such as a wearable module equipped with sensors placed on a subject connected to a computer-linked module, to monitor life signs like heartbeat waveforms and body temperatures. Life signs indicate the health of a living being or a dynamic system (a mechanical system containing moving parts, like motors). The health of the system is defined by a set of known good spectra (such as its frequency/wavelet transform spectrum), with deviations triggering alerts. A garment embedded with a piezoelectric material and an electronic temperature sensor, when placed in contact with the body, captures acoustic waves from the heart and body temperature. Both sensors are connected to a garment-mounted module with an embedded flexible printed antenna (WEM). A separate WEM with reconfigured daughterboard software forms a bidirectional wireless data connection to a computer. A software program compares the received spectrum to its database spectrum and alerts the user when deviation is determined by a set of rules.
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BACKGROUND OF THE INVENTION
The present invention is directed to a diaphragm pressure sensor and a method of fabricating the same, and in particular to a diaphragm pressure sensor for sensing a fluid pressure in, for example, a container for chemicals, a pipe for chemicals or the like, and a method of fabricating the same.
Conventional pressure sensors for sensing a fluid pressure in a container for chemicals, a pipe for chemicals or the like, are generally provided with a diaphragm which acts as a pressure-sensing means, whereby deflection of the diaphragm in response to an applied pressure is translated into an electric signal, to thereby sense a pressure.
Japanese Patent Application No. 2002-130442 discloses an example of such a diaphragm pressure sensor in the invention titled “Electrical capacitance diaphragm pressure sensor”.
Such a diaphragm pressure sensor comprises, for example, :a pressure-sensing element provided with a pressure receiving part including strip-shaped or rectangular flat plate-shaped diaphragms provided in opposing relation, and deposition electrodes formed on opposing surfaces of the diaphragms; a housing element for enclosing the pressure receiving part of the pressure-sensing element, the housing element being made of a material which is resistant to corrosion by a fluid whose pressure is to be detected by the sensor; and an electronic circuit for detecting deflection of the diaphragms.
Such a diaphragm pressure sensor as described above is constituted such that when immersing a housing element in a fluid whose pressure is to be measured, the fluid pressure acts on a pressure receiving part, and any resulting variations in distance between opposing diaphragms cause a change in capacitance.
In a conventional diaphragm pressure sensor such as that described above, a pressure transfer coefficient varies according to a temperature of a fluid whose pressure is to be measured, and instability such as temperature drift and the like is thereby caused, and as a result, measurement accuracy is significantly compromised. It is known that a leading cause of temperature drift in a diaphragm pressure sensor is a thermal expansion/contraction coefficient of a diaphragm material.
With a view to preventing temperature drift from disadvantageously affecting measurement by a diaphragm pressure sensor, a conventional diaphragm pressure sensor, especially a metal diaphragm pressure sensor, employs a temperature compensation circuit in a pressure sensing circuit for sensing a pressure deflection of a diaphragm, or disposes a temperature sensor in a diaphragm to measure a temperature of the diaphragm and provide a compensation electric signal commensurate with the thus measured temperature to a pressure sensing circuit, to thereby compensate for temperature drift, that is, a thermal expansion/contraction coefficient of a diaphragm material in accordance with a temperature.
As a pressure-sensing element, a sapphire diaphragm pressure sensor in which a diaphragm is made of a sapphire plate, and a ceramic diaphragm pressure sensor in which a diaphragm is made of an alumina ceramic plate, are also known. Since sapphire and alumina ceramic have a considerably smaller thermal expansion coefficient compared to metallic materials, they can compensate for temperature drift effectively. However, both a sapphire, which is a crystallization of alumina, and an alumina ceramic, which is made of a sintered body of alumina, gradually erode when they come into contact with a strong acid fluid such as a highly concentrated fluoric acid solution or nitrate solution, and therefore, they are not desirable in terms of corrosion resistance.
Following are a few conventional ways to impart corrosion resistance to a sapphire diaphragm, a ceramic diaphragm or the like.
(1) A fluororesin is applied on the surface of a diaphragm to form a fluororesin coating and thereby improve corrosion resistance. (2) A relatively thick diaphragm of fluororesin is formed, upon which another diaphragm made of a sapphire plate, a ceramic plate or the like is overlaid to fabricate a double diaphragm and thereby improve corrosion resistance.
However, improvement measures such as those described above still cannot solve the following problems:
(1) A fluororesin per se significantly expands and shrinks with temperature, which causes stress strain on a diaphragm and temperature drift in a diaphragm pressure sensor. (2) When a fluororesin is simply applied to the surface of a diaphragm to form a fluororesin coating, such a coating cannot be tightly secured to the diaphragm, and easily peels. (3) As a fluororesin per se is non-adherent, when preparing a double diaphragm, an adhesive containing an amine or the like is employed to bond a fluororesin diaphragm to a diaphragm made of a sapphire plate, a ceramic plate or the like. However, a relatively great thickness of a fluororesin diaphragm, and lack of uniform thickness of an adhesive over a diaphragm, sometimes prevents a pressure from being thoroughly communicated between the fluororesin diaphragm and the diaphragm made of a sapphire plate, a ceramic plate or the like. (4) In a double diaphragm, a relatively thick fluororesin diaphragm allows temperature drift to become great due to thermal expansion/contraction of the fluororesin diaphragm per se. Therefore, a pressure sensor employing such a double diaphragm can be used only under certain temperature conditions.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a diaphragm pressure sensor employing a fluororesin to have both excellent corrosion resistance to a strong acid or alkaline liquid and mechanical strength, and a method of fabricating the same.
According to the present invention, a fluororesin thin film diaphragm pressure sensor comprises: a pressure-sensing element having a pressure-receiving part with a deposition electrode being formed on each of the opposing surfaces of sapphire or alumina ceramic diaphragms which are disposed in opposing relation, and a welding part on a portion of the surface of each of the diaphragms; and a fluororesin base for securing the pressure-sensing element at the welding part of the pressure-sensing element.
The pressure-sensing element is coated with a fluororesin thin film having a crosslinked structure and is welded to the fluororesin base via the fluororesin thin film having a crosslinked structure.
The sensor is configured such that a medium's pressure to be measured is communicated to the pressure-receiving part and any resulting variations in a distance between the deposition electrodes formed on the opposing surfaces of the diaphragms disposed in opposing relation cause a change in capacitance.
According to the present invention, a method of fabricating a fluororesin thin film diaphragm pressure sensor for sensing a fluid pressure comprises the steps of:
forming a pressure-sensing element having a pressure-receiving part with a deposition electrode being formed on each of the opposing surfaces of sapphire or alumina ceramic diaphragms which are provided in opposing relation, and a welding part constituting a portion of the surface of each of the diaphragms;
forming a fluororesin thin film on the pressure-sensing element;
holding the fluororesin thin film formed on the pressure-sensing element at high temperatures, and applying electron beams to the fluororesin thin film, thereby changing the molecular structure of the fluororesin of the fluororesin thin film to a crosslinked structure;
preparing a fluororesin base for securing the pressure-sensing element; and
securing the pressure-sensing element to the fluororesin base at the welding part of the pressure-sensing element via the fluororesin thin film having a crosslinked structure formed on the pressure-sensing element.
According to the present invention, a pressure-sensing element of a diaphragm pressure sensor is made of a fluororesin thin film having a crosslinked structure in which molecules cross-link to form a three-dimensional structure. Therefore, the present invention can provide a diaphragm pressure sensor having improved mechanical characteristics such as toughness, creep resistance or the like without sacrificing inherent strong points of a fluororesin such as lubricity, heat resistance, chemical resistance or the like.
According to the present invention, a fluororesin thin film having a crosslinked structure, which forms a pressure-sensing element of a diaphragm pressure sensor, can be tightly adhered to the surface of a sapphire or ceramic diaphragm or a metal surface as set forth above. Therefore, even though a fluororesin thin film formed on the surface of a sapphire or ceramic is as thin as, for example, several dozen microns, a sensor can still possess sufficient mechanical strength and thus, the present invention can provide a diaphragm pressure sensor having an excellent measurement accuracy while maintaining inherent distortion characteristics of a sapphire or ceramic diaphragm.
As described above, a fluororesin thin film having a crosslinked structure can be tightly adhered to the surface of a sapphire or ceramic diaphragm. Therefore, unlike a prior art in which a fluororesin is bonded to the surface of a sapphire or ceramic by an adhesive for fluororesin or the like with a view to improving corrosion resistance, the present invention does not employ an adhesive for fluororesin or the like as a pressure receiving transmitter. Thus, the present invention can provide a highly accurate diaphragm pressure sensor whose measurement accuracy does not deteriorate due to temperature drift attributable to property modification of an adhesive that occurs with temperature variations.
Still further, a pressure-sensing element of a diaphragm pressure sensor of the present invention is made of a fluororesin thin film having a crosslinked structure and a base for supporting the pressure-sensing element is also produced from a fluororesin; further, an outer cylinder for guiding a fluid whose pressure is to be measured may be made of a fluororesin. Thus, a diaphragm pressure sensor of the present invention can be entirely made of a fluororesin. As a result, the present invention can provide a diaphragm pressure sensor having excellent corrosion resistance and mechanical strength.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a strip-shaped pressure-sensing element constituting a main portion of a diaphragm pressure sensor of the present invention and also describes a basic process for manufacturing the same.
FIG. 2 illustrates a flat plate pressure-sensing element constituting a main portion of a diaphragm pressure sensor of the present invention.
FIGS. 3A–3E describe a basic process for forming a fluororesin thin film portion respectively on a strip-shaped pressure-sensing element and a flat plate pressure-sensing element.
FIGS. 4A–4E illustrate a strip-shaped pressure-sensing element constituting a main portion of a diaphragm pressure sensor of the present invention and a fluororesin base for securing the element and also describe a basic process for manufacturing the same.
FIG. 5 schematically illustrates the diaphragm pressure sensor indicated in FIG. 4 in finished form for practical use.
FIGS. 6A–6D illustrate a flat plate pressure-sensing element constituting a main portion of a diaphragm pressure sensor of the present invention and a fluororesin base for securing the element and also describe a basic process for manufacturing the same.
FIG. 7 schematically illustrates the diaphragm pressure sensor indicated in FIG. 6 in finished form for practical use.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 illustrate a pressure-sensing element constituting a main portion of a diaphragm pressure sensor. More specifically, FIG. 1 is an illustration of strip-shaped pressure-sensing element 10 employing a sapphire plate or ceramic plate for a diaphragm and, as is described later, welding portion 10 A and fluororesin thin film portion 10 B are formed on the pressure-sensing element 10 . Similarly, FIG. 2 is an illustration of flat-plate pressure-sensing element 20 employing a sapphire plate or ceramic plate for a diaphragm, and welding portion 20 A and fluororesin thin film portion 20 B are formed on the pressure-sensing element 20 .
Although FIG. 1 portrays pressure-sensing element 10 simply as a strip-shaped member and, for the sake of simplicity, does not show its details, the element actually consists of two strip-shaped sapphire or alumina ceramic diaphragms arranged in opposing relation with a spacer positioned to lie between them, and deposition electrodes formed on opposing surfaces of the diaphragms, and the two strip-shaped diaphragms are assembled in an integral fashion to constitute a single unit. The opposing deposition electrodes are respectively connected via a lead wire to an electrode output terminal formed at the end of the pressure-sensing element 10 to output a detected signal.
Similarly, although FIG. 2 portrays pressure-sensing element 20 simply as a circular flat plate element and, for the sake of simplicity, does not show its details, it actually consists of two flat plate sapphire or alumina ceramic diaphragms arranged in opposing relation with a spacer positioned to lie between them, the diaphragms having electrodes formed on their opposing surfaces. The two flat plate sapphire or alumina ceramic diaphragms are assembled in an integral fashion to constitute a single unit. The opposing deposition electrodes are respectively connected via a lead wire to an electrode output terminal formed on a part of the pressure-sensing element 20 to output a detected signal.
FIG. 3 schematically describes a process for forming the fluororesin thin film 10 B and fluororesin thin film 20 B on the strip-shaped pressure-sensing element 10 and flat plate pressure-sensing element 20 respectively.
As is illustrated in FIGS. 3A and 3B , a fluororesin PTFE (Polytetrafluoroethylene) solution and a PFA (registered trademark: Tetrafluoroethylene Perfluoroalkoxy vinyl ether copolymer) solution are mixed in a 1:1 ratio and emulsified. It is known empirically that by mixing the aforementioned solutions in a 1:1 ratio, stiffness properties of fluororesin PTFE and thermal solubility characteristics of PFA work effectively for adhesive bonding. Next, the strip-shaped pressure-sensing element 10 and flat-plate pressure-sensing element 20 are immersed in a fluororesin solution to coat the elements with fluororesin and form the fluororesin thin film portion 10 B on the strip-shaped pressure-sensing element 10 and the fluororesin thin film portion 20 B on the flat plate pressure-sensing element 20 respectively. Further, by rotating the pressure-sensing element 10 ( 20 ) coated with a fluororesin by a thin film forming instrument, for example, on spin coater 31 that rotates at high speeds, a fluororesin thin film is formed on the surface of the diaphragm, and the thus formed film is leveled. To attain a desired thickness of a fluororesin thin film on the surface of a diaphragm, the above-described procedure is repeated as needed.
Next, as is illustrated in FIG. 3E , the pressure-sensing element 10 , 20 on which a thin film of a desired uniform thickness is formed is processed by electron beam irradiation system 32 . As is already well known in the technical field, the electron beam irradiation system 32 comprises DC high voltage power supply 33 , and electron beam emission cathode 35 , electron beam accelerator 36 , scanning deflection coil 37 and irradiation base 38 which are housed in closed vessel 34 .
Hereunder, it will be described more specifically how the electron beam irradiation system 32 processes a fluororesin thin film.
First, the pressure-sensing element 10 ( 20 ) on which a fluororesin thin film is formed is placed on the irradiation base 38 , and the closed vessel 34 is filled with an inactive gas such as an argon gas, nitrogen gas or the like via inlet valve 39 A and further, the interior of the closed vessel 34 is heated at elevated temperatures of 330° C. ˜390° C., which correspond to a melting point of a fluororesin until distribution of temperature becomes uniform throughout the pressure sensing element 10 ( 20 ).
Next, an electron beam is applied to the fluororesin thin film on the pressure-sensing element 10 ( 20 ). More specifically, an electron beam excited by the DC high voltage power supply 33 is emitted from the electron beam emission cathode 35 and accelerated by the electron beam accelerator 36 . The scanning deflection coil 37 controls the direction of the electron beam whereby the fluororesin thin film on the pressure-sensing element 10 ( 20 ) is uniformly irradiated with the electron beam. The pressure-sensing element 10 ( 20 ) may be moved by an adequate instrument equipped with a rolling mechanism in the closed vessel 34 (not indicated in the drawing) so that electron beam can be applied both to the top and the bottom of the element 10 ( 20 ).
Upon application of the electron beam to the fluororesin thin film on the pressure-sensing element 10 ( 20 ), the temperature inside the closed vessel 34 is gradually reduced to room temperature, and the inactive gas in the closed vessel 34 is released through exhaust valve 39 B. Subsequently, the pressure-sensing element 10 ( 20 ) whose fluororesin thin film was processed with electron beam (radiation) is taken out of the closed vessel 34 .
When an electron beam is applied to fluororesin held at high temperatures, the molecular structure of the fluororesin changes to a covalent linkage in which the molecules cross-link to form a three-dimensional structure. Such a structure is known as a crosslinked structure of fluororesin and the molecular structural change as described above is called a crosslinking reaction. A crosslinked structure of fluororesin advantageously eliminates the use of an adhesive, improves the adhesion of a fluororesin thin film to the surface of a sapphire or alumina ceramic diaphragm and enhances abrasive resistance, stiffness and mechanical strength of the surface of a fluororesin thin film.
A fluororesin thin film is a normally white and opaque crystalline thin film. When it is kept under high temperature conditions and subjected to electron beam processing, so that it is modified to have a crosslinked structure, it loses its crystal structure and becomes colorless and transparent, by which it can be confirmed that the electron beam processing is complete.
FIG. 4 illustrates a basic process for manufacturing a diaphragm pressure sensor by employing the strip-shaped pressure-sensing element 10 ( FIG. 4A ) whose fluororesin thin film has been held at high temperatures and further subjected to electron beam processing as described above.
FIG. 4B is a plan view of fluororesin base 41 for securing a diaphragm, whereas FIG. 4C is a section view of the midsection of the same. As indicated in the drawings, the fluororesin base 41 has in the center, rectangular slit 41 A, through which the strip-shaped pressure-sensing element 10 is inserted, and adhering portion 41 B is formed in an approximately rectangular groove that surrounds the slit 41 A, to secure the pressure-sensing element 10 . Further, ring-shaped projection 41 C for securing a metal outer cylinder ( FIG. 6 , 60 ) which houses the fluororesin thin film portion 10 B constituting a pressure-receiving portion of the pressure-sensing element 10 , is provided on the underside of the fluororesin base 41 .
FIG. 4D is an assembly drawing of the strip-shaped pressure-sensing element 10 and the fluororesin base 41 whereas FIG. 4E is a lateral cross section of the same. The pressure-sensing element 10 is inserted into the slit 41 A of the fluororesin base 41 to the extent that the welding portion 10 A of the element 10 aligns with the slit 41 A on the base 41 , and fluororesin welding agents 42 and 43 are injected into the adhering portion 41 B, whereby the pressure-sensing element 10 having the fluororesin thin film portion 10 B of a crosslinked structure is secured to the fluororesin base 41 by means of high temperature welding to define a pressure-receiving portion of the pressure-sensing element 10 .
As illustrated in FIG. 5 , the strip-shaped diaphragm pressure sensor indicated in FIG. 4 may be installed in, for example, a pipe for chemicals (not indicated in the drawing), in which case the fluororesin outer cylinder 50 together with the pressure-receiving portion of the pressure-sensing element 10 is immersed directly in a chemical solution and a pressure of the chemical solution drawn into the cylinder 50 is measured. In other words, a measured pressure of a chemical solution is transferred to the pressure receiving portion of the pressure-sensing element 10 and a change in capacitance caused by variations in a distance between the diaphragms provided in opposing relation is output as a detected signal from the pressure-sensing circuit 51 . Thus, any part of the diaphragm pressure sensor, which comes into contact with a solution whose pressure is measured, may be produced from fluororesin. Further, if a metal outer cylinder is employed in place of the fluororesin outer cylinder 50 , the parts of the sensor that come into contact with a solution can still be made of fluororesin simply by coating the metal cylinder with a fluororesin film.
FIG. 6 illustrates a basic process for manufacturing a diaphragm pressure sensor by using the circular flat plate pressure sensing element 20 ( FIG. 6A ) whose fluororesin thin film has been held at high temperatures and subjected to electron beam processing.
FIG. 6B is a plan view of the ring-shaped fluororesin base 61 for securing a diaphragm whereas FIG. 6C is a section view of the midsection of the same. As indicated in the drawing, first ring portion 61 A and second ring portion 61 B are formed on the ring-shaped fluororesin base 61 in such a manner that the internal diameter of the second ring portion 61 B is greater than that of the first ring portion 61 A. Next, as indicated in FIG. 6D , the pressure-sensing element 20 is mounted on the first ring-shaped portion 61 A, and the welding portion 20 A formed on the periphery of the pressure-sensing element 20 is secured to the top part of the ring-shaped portion 61 A by means of high temperature welding, using the fluororesin welding agent 62 to thereby define a pressure-receiving portion of the pressure-sensing element 20 .
The flat plate diaphragm pressure sensor indicated in FIG. 7 may be installed in, for example, a pipe for chemicals (not indicated in the drawing), in which case the fluororesin outer cylinder 70 together with the pressure-receiving portion of the pressure-sensing element 20 is immersed directly in a chemical solution and a pressure of the chemical solution drawn into the cylinder 70 is measured. In other words, a measured pressure of a chemical solution is transferred to the pressure receiving portion of the pressure-sensing element 20 and a change in capacitance caused by variations in a distance between the diaphragms provided in opposing relation is output as a detected signal from the pressure-sensing circuit 71 . Thus, any part of the diaphragm pressure sensor which comes into contact with a solution whose pressure is measured may be produced from fluororesin. Further, if a metal outer cylinder is employed in place of the fluororesin outer cylinder 70 , the parts of the sensor that come into contact with a solution can still be made of fluororesin simply by coating the metal cylinder with a fluororesin film.
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The present invention provides a highly corrosion-resistant diaphragm pressure sensor capable of obviating the effects of temperature drift that arises when a pressure-travel coefficient changes with temperature of a fluid whose pressure is sensed, and a method of manufacturing the same. A fluororesin thin film diaphragm pressure sensor comprises a pressure sensing element ( 10, 20 ) having a pressure receiving part with a deposition electrode formed on each of the opposing faces of sapphire or alumina ceramic diaphragms which are arranged in opposing relation, and a welding portion ( 10 A, 20 A) on a part of each of the surfaces of the diaphragms; and a fluororesin base ( 41, 61 ) for securing the pressure sensing element at the welding portion of the pressure sensing element. The pressure sensing element is coated with a fluororesin thin film having a cross-linked structure, and the pressure sensing element and the fluororesin base are welded together via the fluororesin thin film having a cross-linked structure.
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FIELD OF THE INVENTION
The present invention is related to techniques for increasing the performance and data throughput of ASIC devices, such as Synchronous Dynamic Random Access Memories (SDRAMs) and, more particularly, to techniques for adaptive determination of one or more timing signals associated with such ASIC devices.
BACKGROUND OF THE INVENTION
As the performance and data throughput requirements for networking and computing applications increase, the performance and data throughput requirements for many of the required individual subsystems also increase. Transferring data between the main memory and the system processor, for example, is often a significant performance bottleneck in any computing system. Even the fastest standard Dynamic Random Access Memory (DRAM) cannot keep up with the ever increasing bus speeds used on many computing systems.
Synchronous Dynamic RAM (SDRAM) is a type of DRAM that demonstrates improved performance and data throughput. While DRAM has an asynchronous interface (i.e., it immediately reacts to changes in its control inputs), SDRAM has a synchronous interface (i.e., it waits for a clock pulse before responding to its control inputs). Likewise, Double Data Rate (DDR) SDRAM is a further evolution of SDRAM that is used in many computing systems. As originally proposed, SDRAM acts on only the rising edge of the clock signal (i.e., each low-to-high transition). DDR SDRAM, on the other hand, acts on both the rising and falling edges, thereby potentially increasing the data rate by a factor of two. Further performance improvements are obtained in DDR-2 (2×) and QDR-2 (4×) by phase shifting the clock signal to obtain additional rising and falling edges.
SDRAM enjoys wide spread application in both low-end consumer computing applications, as well as in high end networking switches and routers. A DDR2 SDRAM interface protocol, for example, is used for communications between an integrated circuit (e.g., a memory controller) and an external memory. See, e.g., JEDEC Standard, DDR2 SDRAM Specification, JESD79-2A (January 2004), incorporated by reference herein. A parallel bus between the memory controller and the external memory typically carries parallel data that is being read from or written to the external memory. In addition, the memory controller provides a system clock CK to the external memory. In this manner, synchronization among the various signals on the parallel bus can be accomplished, for example, by a phase locked loop that generates the system clock CK. According to the DDR2 SDRAM Specification, the external memory will transmit a number of n+1 bit words DQ[ 0 :n] and a data strobe signal, DQS, back to the controller in response to a read request, RD, from the controller.
The DQS signal and the data bits DQ[ 0 :n] are ideally edge aligned. While the DQS signal is inactive, it is held in an undriven, high impedance (HI-Z) state. The controller should not utilize the DQS signal while it is in the HI-Z state, which would cause unpredictable results in the controller. Therefore, the DQS signal must be gated (e.g., AND or NAND gated) into the controller at the appropriate time (i.e., the time at which it is “safe” for the controller to use the DQS signal as an input). Read preamble and read postamble symbols bracket in time the usable portion of the DQS signal, in a known manner.
A number of techniques have been proposed or suggested for the controller to determine when to process the DQS signal during a read operation. Most techniques, especially for high data rates, rely on a priori design understandings to incorporate critical timing into the controller in a “hard-wired” fashion. It has been found, however, that hard-wiring a single timing relationship into the DDR2 controller reduces the noise margin. In addition, this hard-wired approach also results in the rejection of some system configurations as impossible to meet timing. Further, aging effects could result in erroneous operation of the controller. A need therefore exists for methods and apparatus for adaptive determination of one or more timing signals, such as DDR2 DQS timing, in such ASIC devices.
SUMMARY OF THE INVENTION
Generally, methods and apparatus are provided for adaptive determination of timing signals, such as on a high speed parallel bus. According to one aspect of the invention, a method is provided for adaptive determination of a timing signal having a first edge with respect to an internal clock, wherein the timing signal includes a period in which the timing signal is undriven, followed by a period immediately before a first transition in which the timing signal is in a predefined state. The timing signal is evaluated using one or more comparators; and an output of the one or more comparators are latched based on a clock signal. The clock signal is adjusted until the one or more comparators indicate the timing signal is in the predefined state. The clock signal is further adjusted until the one or more comparators indicate the first transition has been reached. Thereafter, a gating control signal is established based on a timing of the first transition.
The timing signal can be received, for example, from a memory in response to a read request. The comparators can compare the timing signal to one or more controllable voltage levels. The period in which the timing signal is undriven can be, for example, a high-impedance state. The timing signal may be a data strobe signal. The period when the signal has a predefined state can be a preamble period or a postamble period.
A more complete understanding of the present invention, as well as further features and advantages of the present invention, will be obtained by reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a DDR2 SDRAM interface protocol used for communications between an integrated circuit and an external memory;
FIG. 2 illustrates the parallel data signals, DQn, and the data strobe signal DQS, of FIG. 1 in further detail;
FIG. 3 illustrates a timing relationship of the DQS signal and DQ[0:n] data bits on the parallel bus inside the memory controller of FIG. 1 after the DQS signal has been delayed and the HI-Z states have been removed by the gating function;
FIG. 4 illustrates a read command RD and the system clock CK as they originate in the controller for transmission to the external memory and the latest and earliest arrival of the DQS signal returned from the memory to the memory controller;
FIG. 5 is a schematic block diagram of an improved DDR2 controller incorporating features of the present invention;
FIG. 6 illustrates an initial exemplary placement of the L-CLK signal during the calibration routine of the present invention;
FIGS. 6 through 11 illustrate the calibration of the control inputs VCMPLO, VCMPCM, and VCMPHI of the three comparators CMPL, CMPM, CMPH of FIG. 5 for various exemplary placements of the L-CLK signal during the calibration routine by the controller of FIG. 5 ;
FIG. 12 illustrates the control inputs VCMPLO, VCMPCM, and VCMPHI of the three comparators CMPL, CMPM, CMPH in the preamble region, after determination of the appropriate signal levels;
FIGS. 13 through 15 illustrate the L-CLK timing for identifying the beginning, middle and end of the first DQS rising edge, respectively;
FIG. 16 is a schematic block diagram of an alternate DDR2 controller incorporating features of the present invention; and
FIG. 17 illustrates the timing of the signals of FIG. 16 .
DETAILED DESCRIPTION
The present invention provides methods and apparatus for adaptive determination of one or more timing signals, such as DDR2 DQS timing. While the present invention is illustrated in the context of a DQS signal in a DDR2 SDRAM, the present invention can be applied for the adaptive determination of any timing signal where the timing of a first edge with respect to an internal clock must be determined; and the signal has a period in which it is undriven, i.e., has a high-Z state; has a period immediately before the first transition in which the signal is in a known and valid state (i.e., 0 or 1); and has a particular timing relationship established with other signal inputs to the controller and which timing relationship must be altered.
In order to aid understanding of an improved memory controller in accordance with the present invention, the operation of a memory controller is discussed in conjunction with FIGS. 1 and 2 . FIG. 1 illustrates a DDR2 SDRAM interface protocol used for communications between an integrated circuit 110 (e.g., a memory controller) and an external memory 120 . See, e.g., JEDEC Standard, DDR2 SDRAM Specification, JESD79-2A (January 2004), incorporated by reference herein. As shown in FIG. 1 , a parallel bus 150 between the memory controller 110 and the external memory 120 carries parallel data that is being read from or written to the external memory. In addition, the memory controller 110 provides a system clock CK to the external memory 120 . In this manner, synchronization among the various signals on the parallel bus 150 can be accomplished, for example, by a phase locked loop that generates the system clock CK. According to the DDR2 SDRAM Specification, the external memory 120 will transmit a number of n+1 bit words DQ[ 0 :n] and a data strobe signal, DQS, back to the controller 110 in response to a read request, RD, from the controller 110 .
FIG. 2 illustrates the parallel data signals, DQn, and the data strobe signal DQS, of FIG. 1 in further detail. As shown in FIG. 2 , the DQS signal and the data bits DQ[ 0 :n] are ideally edge aligned. While the DQS signal is inactive, it is held in an undriven, high impedance (HI-Z) state. The controller 110 should not utilize the DQS signal while it is in the HI-Z state, which would cause unpredictable results in the controller 110 . Therefore, the DQS signal must be gated (e.g., AND or NAND gated) into the controller 110 at the appropriate time (i.e., the time at which it is “safe” for the controller 110 to use the DQS signal as an input). FIG. 2 also illustrates the read preamble and read postamble symbols that together bracket in time the usable portion of the DQS signal, in a known manner.
As previously indicated, the DQS signal and the data bits DQ[ 0 :n] are ideally edge aligned. Further, the controller 110 must determine when to process the DQS signal during a read operation. The controller 110 must then delay the DQS signal by an appropriate amount so that it may be used as a strobe to clock the data into the controller. FIG. 3 illustrates a timing relationship of the DQS signal and DQ[0:n] data bits in the memory controller 110 after the DQS signal has been delayed and the HI-Z states have been removed by the gating function (e.g., AND or NAND gates).
An important design challenge is the specification, at an appropriate time, of the signal that enables the gating of the DQS signal into the controller circuitry. FIG. 4 illustrates a read command RD and the system clock CK as they originate in the controller 110 for transmission to the external memory 120 . As shown in FIG. 4 , a rising edge of CK strobes the read line and transmits a read pulse to the memory. FIG. 4 also demonstrates two extremes 410 , 420 in the arrival time of the DQS signal at the controller 110 from the memory 120 . The variation in arrival times from one system to another can be caused by, for example, memory controller integrated circuit (IC) process and temperature variation, memory process and temperature variation, and printed circuit board variation (e.g., in components, board signal path lengths, and board material properties).
Typically, a CK edge after the rising edge that strobes the RD pulse is selected as the timing instance 450 to gate the DQS signal. This CK edge must not occur during the Hi-Z portion or after the leading edge of the first data, i.e., it must occur during the preamble. Further, this CK edge must occur during the preamble of all possible arriving DQS signals. FIG. 4 demonstrates that, for this exemplary system, selection of the second falling CK edge after the rising CK edge which strobes the RD pulse would be acceptable as the timing instance 450 to gate the DQS signal. Situations may arise in which it is difficult or even impossible to identify the same CK edge for this gate enable function that is appropriate over all variations (arrival times). As previously indicated, this identification is typically “hard-wired” into the controller 110 for conventional techniques.
Generally, the present invention provides an interface that for all ranges of conditions allows an appropriate clock edge to be selected by the controller 110 as the timing instance 450 to gate the DQS signal. The disclosed DDR2 controller techniques address the following four known challenges:
1. protection of the controller circuitry from the Hi-Z states of the DQS signal;
2. delay of the DQS signal by an appropriate amount (such as ¼ system clock period);
3. establishment of timing over controller, board, and memory PVT variations; and
4. aging effects.
Improved DDR2 Controller with Delay Line
FIG. 5 is a schematic block diagram of an improved DDR2 controller 500 incorporating features of the present invention. As shown in FIG. 5 , the DQS signal received from the memory 120 in response to a read-from-memory request is distributed to a number of exemplary comparators CMPL, CMPM, CMPH and, through a gating circuit 510 , such as an AND gate, to a programmable delay line 520 . The voltage levels against which DQS is compared are provided by three control signals VCMPLO, VCMPCM, VCMPHI. These three signals are provided by a subsystem controller 530 . The subsystem controller 530 can set these three control signals VCMPLO, VCMPCM, VCMPHI to a range of voltage levels. The comparator outputs would be binary if both + and − inputs were valid. For instance, the comparator output would be “1” if the “+” input were greater than the “−” input and “0” otherwise. The comparators will behave in a particular manner when experiencing Hi-Z inputs as described below.
The digital outputs of the comparators CMPL, CMPM, CMPH are latched by three flip-flops FFL, FFM, FFH. The time at which these flip-flops FFL, FFM, FFH latch the outputs of the comparators CMPL, CMPM, CMPH is determined by a clock, L-CLK, provided by the subsystem controller 530 . The subsystem controller 530 can adjust the time of the L-CLK edges within a certain range. A delayed version of DQS is created by the programmable delay line 520 . The delay value of the programmable delay line 520 is provided by the subsystem controller 530 . The gating circuit 510 is controlled by a gating control signal provided by the subsystem controller 530 . The determination of the timing of this gating control signal is described further below. Generally, for correct operation, the gating control signal must occur after the Hi-Z state and before the first edge of DQS, i.e. during the preamble.
According to one aspect of the invention, a calibration routine is performed to determine the delay between the system clock edge that strobes the RD signal and the arrival at the controller of both the end of the Hi-Z state and the first valid DQS edge. During the calibration routine, the controller 110 will issue a sequence of read-from-memory requests. The data DQ[ 0 :n] produced by the memory 120 during this activity are irrelevant. The DQS signals will be scrutinized to find the delays mentioned above.
FIG. 6 illustrates an initial exemplary placement of the L-CLK at a time position 610 during the calibration routine. The L-CLK is positioned well before the expected arrival of the DQS preamble after the round trip of the RD signal from the controller 110 to the memory 120 and then back again to the controller 110 . The comparators CMPL, CMPM, CMPH should respond to Hi-Z inputs in a uniquely identifiable manner.
For instance, CMPL and CMPH can be designed to output a “0” when their respective “+” input experiences a Hi-Z value. CMPM can be designed to output a “1” when its respective “+” input experiences a Hi-Z value. The subsystem controller 530 will initially set the control signals VCMPLO, VCMPCM, and VCMPHI all to an approximate DQS mid-signal level as shown in FIG. 7 . The L-CLK position 610 will cause the three flip-flops (FFL, FFM, and FFH) to latch (L-M-H)=(010) because all comparator “+” inputs (DQS) are in the Hi-Z state. This is an impossible result for any valid, real voltage input other than Hi-Z. As long as the controller 530 senses a (010) result it knows that the L-CLK signal is in the Hi-Z region.
The subsystem controller 530 can now gradually move the L-CLK to later times, such as a time 710 , until L-CLK emerges into the preamble (or another known and valid state), as shown in FIG. 8 . For example, as illustrated in FIG. 9 , if the comparators CMPL, CMPM, CMPH collectively cause the flip flops to latch (000), indicating that the measured DQS signal is below each of the three control signals VCMPLO, VCMPCM, VCMPHI that have been set to an approximate DQS mid-signal level, then the subsystem controller 530 can determine that L-CLK has emerged into the preamble.
Once the subsystem controller 530 has encountered the preamble, the calibration routine proceeds to determine an approximation to the signal levels VCMPLO, VCMPCM, and VCMPHI in the preamble region. The VCMPLO control signal is adjusted until it no longer statistically indicates that its input is lower than its reference level. This is illustrated in FIG. 10 . The VCMPHI control signal is then moved an amount higher than VCMPCM which equals the amount that VCMPCM is higher than VCMPLO. This is illustrated in FIG. 11 . These values become the first approximation for the comparator reference voltages. The calibration routine will have the capability of refining these levels for greater accuracy.
FIG. 12 again illustrates the control inputs VCMPLO, VCMPCM, and VCMPHI of the three comparators CMPL, CMPM, CMPH in the preamble region as the controller 530 moves the L-CLK time. The subsystem controller 530 continues to move the L-CLK signal to later times, such as position 1310 , until the situation in FIG. 13 is encountered. Generally, FIG. 13 illustrates the L-CLK timing at position 1310 for identifying the beginning of the first DQS rising edge.
As the first DQS rising edge of the DQS signal is approached, the statistical response of the comparator CMPL will begin to change. The subsystem controller 530 can identify this condition as the beginning of the first rising DQS edge. Similarly, as the subsystem controller 530 varies the L-CLK signal to positions 1410 and 1510 , respectively, as shown in FIGS. 14 and 15 , the subsystem controller 530 can identify the middle (VCMPCM) and end (VCMPHI) of the first rising DQS edge, respectively. Thus, FIGS. 14 through 15 illustrate the L-CLK timing for identifying the beginning, middle and end of the first DQS rising edge, respectively.
Once the subsystem controller 530 has determined the time interval between the system clock edge that clocks the RD request and (a) the beginning of the preamble ( FIG. 8 ) and (b) the middle of the first DQS rising edge ( FIG. 14 ), the timing of the gating control signal ( FIG. 5 ) can be established. This will allow the DQS signal into the delay line 520 after the Hi-Z state and before the first rising DQS edge. The delay line timing control ( FIG. 5 ), which will have been determined by well-established techniques, will then enforce a ¼ system clock period delay on DQS to result in the timing shown if FIG. 3 .
Improved DDR2 Controller without Delay Line
FIG. 16 is a schematic block diagram of an alternate DDR2 controller 1600 incorporating features of the present invention. The DDR2 controller 1600 shown in FIG. 16 does not employ the delay line of FIG. 5 . The techniques described above in conjunction with FIG. 5 are used to identify the time delays between the system clock edge that strobes the RD request and the beginning of the preamble and the first rising DQS edge. The middle flip flop FFM is designed to respond to both edges of L-CLK. The sub-system controller 1630 then issues an L-CLK signal with appropriate timing such that the Q output of the middle flip flop FFM can be used as the delayed DQS, as shown in FIG. 16 . The timing of the signals 1700 is shown in FIG. 17 . This timing now satisfies the requirements as shown in FIG. 3 . Alternatively, the L-CLK signal itself can be adjusted in time so as to serve as the delayed DQS signal to strobe the DQ[0:n] data.
While exemplary embodiments of the present invention have been described with respect to digital logic blocks, such as subsystem controller 530 , as would be apparent to one skilled in the art, various functions may be implemented in the digital domain as processing steps in a software program, in hardware by circuit elements or state machines, or in combination of both software and hardware. Such software may be employed in, for example, a digital signal processor, micro-controller, or general-purpose computer. Such hardware and software may be embodied within circuits implemented within an integrated circuit.
Thus, the functions of the present invention can be embodied in the form of methods and apparatuses for practicing those methods. One or more aspects of the present invention can be embodied in the form of program code, for example, whether stored in a storage medium, loaded into and/or executed by a machine, or transmitted over some transmission medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code segments combine with the processor to provide a device that operates analogously to specific logic circuits.
A plurality of identical die are typically formed in a repeated pattern on a surface of the wafer. Each die includes a device described herein, and may include other structures or circuits. The individual die are cut or diced from the wafer, then packaged as an integrated circuit. One skilled in the art would know how to dice wafers and package die to produce integrated circuits. Integrated circuits so manufactured are considered part of this invention.
It is to be understood that the embodiments and variations shown and described herein are merely illustrative of the principles of this invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention.
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Methods and apparatus are provided for adaptive determination of timing signals, such as on a high speed parallel bus. The invention adaptively determines a timing signal having a first edge with respect to an internal clock, wherein the timing signal includes a period in which the timing signal is undriven, followed by a period immediately before a first transition in which the timing signal is in a predefined state. The timing signal is evaluated using one or more comparators; and an output of the one or more comparators are latched based on a clock signal. The clock signal is adjusted until the one or more comparators indicate the timing signal is in the known and valid state. The clock signal is further adjusted until the one or more comparators indicate the first transition has been reached. Thereafter, a gating control signal is established based on a timing of the first transition.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of U.S. Provisional Patent Application No. 61/630,601 filed Dec. 15, 2011, the disclosure of which is incorporated by reference in its entirety.
STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
REFERENCE TO A COMPACT DISK APPENDIX
[0004] Not applicable.
BACKGROUND OF INVENTION
[0005] 1. Field of the Invention
[0006] This invention relates to an apparatus and method for performing physical exercise, and particularly to a system that is portable and improves body strength in an efficient, functional, and safe way.
[0007] 2. Description of the Related Art
[0008] Exercise machines that are used only in certain limited body positions, isolate muscle groups, move the spine from a flexed to an extended position, are difficult or complicated to use, are difficult and expensive to manufacture, and are bulky and not portable, are known in the art.
[0009] The present invention is a total body exercise system that provides many advantages over the prior art. Performing exercises using the present invention allows the extremities to move through a full range of motion while the operator is standing, lying prone, lying supine, or lying on one side, and also exercises the extremities in many combinations, including a combination of legs and arms at the same time, arms only, legs only, one arm and one leg on the same side of the body, or one leg and one arm on opposite sides of the body, thereby maximizing the strengthening and conditioning effects achieved by the operator. Further, the present invention strengthens and conditions the muscles in a functional way, whereby muscles are exercised as functional groups, in contrast to prior art exercise devices that isolate muscle groups. In addition, the present invention strengthens and conditions the trunk and core, including the neck, chest, abdominal, and back muscles, while simultaneously strengthening and conditioning the muscles of the extremities, thereby providing a balance of strength and conditioning between different muscle groups, which maximizes total body strength, conditioning, and flexibility, and avoids and prevents injury. In addition, in contrast to prior art exercise machines that move the spine from a flexed to an extended position, the present invention strengthens and conditions the trunk and core and the extremities while maintaining the spine in its naturally safe lordotic curved position in multiple positions of use by the operator, including standing, lying prone, lying supine, and lying on one side, thereby avoiding and preventing injury. Finally, the present invention provides a total body exercise system that is light, compact, and portable, which is advantageous when storing the exercise system, shipping it, or moving or traveling with it.
SUMMARY OF INVENTION
[0010] The present invention provides an apparatus and method for performing physical exercise that is novel and useful in providing a portable system that improves strength and conditioning of the operator in a safe, efficient, and functional way, in which the spine is kept in its safe and natural position and opposing muscle groups are strengthened and conditioned to similar levels, which is ideal for efficient and proper strengthening and conditioning and ayoidance of injury.
[0011] According to one embodiment of the present invention, an exercise system comprises an elongated member, a hollow member, and at least one resistance band. The elongated member may be positioned within the hollow member, and the elongated member and the hollow member may be slidably moveable relative to each other. At least one resistance band may be secured at one securing location on the elongated member and at one securing location on the hollow member. Movement of the hollow member and the elongated member relative to each other by the operator stretches a resistance band, which creates resistance to the movement, thereby exercising, strengthening, and conditioning the operator.
[0012] In another embodiment, the exercise system may further include a pair of handles that that are attached to the hollow member and extending outwardly from the hollow member. The handles are adapted to receive force, which if large enough to overcome the resistance created by a resistance band, will slidably move the hollow member and the elongated member relative to each other. Force may be applied to one or both of the handles by one or both hands of the operator.
[0013] In another embodiment, the exercise system may further include a foot board system with a foot board tube that is attached to the elongated member and extending outwardly from the elongated member. The foot board system is adapted to receive force, which if large enough to overcome the resistance created by a resistance band, will slidably move the hollow member and the elongated member relative to each other. Force may be applied to the foot board system by one or both feet of the operator.
[0014] In another embodiment, force may be applied to one or both of the handles by one or both hands of the operator in one direction, and at the same time force may be applied to the foot board system by one or both feet of the operator in the opposite direction.
[0015] In another embodiment, the elongated member includes two ends, a foot board end where a foot board tube of the foot board system may be attached, and a head end where one or more band anchors may be attached. The hollow member includes two ends, a handle end where the handles may be attached, and a feet end where one or more band anchors may be attached. The elongated member is positioned within the hollow member in such a way that the handle end of the hollow member is generally situated at or toward the opposite end of the exercise system from the foot board end of the elongated member. The foot board end of the elongated member comprises the distal end of the exercise system, and the head end of the elongated member comprises the proximal end of the exercise system. The securing locations on the elongated tube to which a resistance band may be secured include the foot board tube, one or more band anchors attached to the foot board tube, and one or more band anchors attached to the head end of the elongated member. The securing locations on the hollow member to which a resistance band may be secured include one or more band anchors attached to the feet end of the hollow member, and one or both handles attached to the handle end of the hollow member.
[0016] In another embodiment, the elongated member may be substantially longer than the hollow member, by at least about twice the length of the hollow member, and the distance the hollow member and the elongated member may be slidably moved relative to each other may be at least about the length of the elongated member.
[0017] In another embodiment, the outside diameter or dimensions of the elongated member may be slightly smaller than the inside diameter or dimensions of the hollow member, by at least enough distance to allow the elongated member and the hollow member to be slidably moved relative to each other.
BRIEF DESCRIPTION OF DRAWINGS
[0018] A more complete appreciation of the present invention is provided by reference to the following detailed description of the appended drawings and figures. The following description in conjunction with the appended figures enables a person having skill in the art to recognize the numerous advantages and features of the present invention by understanding the various disclosed embodiments. It should be understood, however, the invention is not limited to the precise arrangements in the instrumentality shown. The following figures are utilized to best illustrate these features:
[0019] FIG. 1 provides a front elevation view of a total body exercise system according to one aspect of the invention;
[0020] FIG. 2 provides an exploded view of a total body exercise system according to one aspect of the invention;
[0021] FIG. 3 provides a side elevation view of a total body exercise system according to one aspect of the invention;
[0022] FIG. 3 a provides a partial view of a total body exercise system according to one aspect of the invention;
[0023] FIG. 3 b provides a front elevation view of a total body exercise system according to one aspect of the invention;
[0024] FIGS. 4 a - 25 b provide perspective views of a total body exercise system in use according to one aspect of the invention.
DETAILED DESCRIPTION OF INVENTION
[0025] The following discussion is presented to enable a person skilled in the art to make and use the present invention. The general principles described herein may be applied to embodiments and applications other than those specifically detailed below without departing from the spirit and scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments expressly shown, but is to be accorded the widest possible scope of invention consistent with the principles and features disclosed herein.
[0026] Referring to FIGS. 1-3 b, a preferred embodiment of a total body exercise system 26 of the present invention is shown. The elongated member 27 includes two ends, a foot board end 37 where a foot board tube 38 is attached, and a head end 31 where one or more band anchors 32 may be attached. The hollow member 28 includes two ends, a handle end 41 where the handles 30 may be attached, and a feet end 47 where one or more band anchors 34 may be attached. The elongated member 27 is positioned within the hollow member 28 in such a way that the handle end 41 of the hollow member 28 is generally situated at or toward the opposite end of the exercise system 26 from the foot board end 37 of the elongated member 27 . The foot board end 37 of the elongated member 27 comprises the distal end 49 of the exercise system 26 , and the head end 31 of the elongated member 27 comprises the proximal end 39 of the exercise system 26 . The outside diameter or dimension of the elongated member 27 is slightly smaller than the inside diameter or dimension of the hollow member 28 , by at least enough distance to allow the elongated member 27 and the hollow member 28 to be slidably moved relative to each other. The elongated member 27 is substantially longer than the hollow member 28 , by at least about twice the length of the hollow member 28 , and the distance the hollow member 28 and the elongated member 27 may be slidably moved relative to each other is at least about the length of the hollow member 28 . The elongated member 27 is preferably constructed in a single piece. In other embodiments, elongated member 27 is constructed in two or more sections which are assembled into a single piece for use of the exercise system 26 by the operator, and may be disassembled when the exercise system 26 is not in use. In one embodiment, the sections are assembled by pressing one end of one section into one end of another section. In another embodiment, the sections are assembled by inserting and tightening one end of one section threaded with male threads into one end of another section threaded with female threads. The sections may be assembled using other methods as known in the art with departing from the spirit and scope of the present invention. The elongated member 27 and/or the hollow member 28 are preferably made of fiberglass, but also may be made of carbon fiber, metal, plastic, wood, or any other material that is sufficiently strong to withstand the forces of use of the exercise system 26 by the operator without breaking or excessively bending, meaning bending to such a degree that slidable movement of the elongated member 27 relative to the hollow member 28 becomes difficult or impossible when the exercise system 26 is in use by the operator, without departing from the spirit and scope of the present invention. The elongated member 27 and the hollow member 28 are shown as tubular in shape, meaning circular in cross section, but may also be provided in shapes other than tubular, such as oval, square, rectangular, or triangular in cross section, or other geometric shapes, without departing from the spirit and scope of the present invention.
[0027] The head end 31 of elongated member 27 is flanged, in which the outside diameter or dimension of the head end 31 of elongated member 27 is slightly larger than the outside diameter or dimension of the remainder of the elongated member 27 , and the outside diameter or dimension of the flanged portion 33 of the elongated member 27 is about equal to the outside diameter or dimension of the handle end 41 of hollow member 28 , such that when the head end 31 of the elongated member 27 slidably moves toward the handle end 41 of hollow member 28 , contact between the flanged portion 33 of the elongated member 27 and the handle end 41 of the hollow member 28 prevents any further such slidable movement in that direction. The feet end 47 of hollow member 28 is also flanged in a similar manner to the flanged portion 33 of the elongated member 27 , and the flanged portion 43 of hollow member 28 is slightly larger than the outside diameter or dimension of the remainder of the hollow member 28 , by about the same proportion as the increase in diameter or dimension of the flanged portion 33 of the elongated member 27 relative to the diameter or dimension of the remainder of the elongated member 27 , and the extra thickness of the hollow member 28 at the feet end 47 may provide increased depth in which to secure band anchors 34 L and 34 R. The dimensions of flanged portion 33 of elongated member 27 and/or the flanged portion 43 of hollow member 28 may be modified, or flanged portion 33 and/or the flanged portion 43 may be omitted, without departing from the spirit and scope of the present invention.
[0028] Referring to FIGS. 1-3 b, certain components are preferably affixed to the elongated member 27 , the hollow member 28 , or other components. Components may be affixed by welding, gluing, or other methods as known in the art which do not allow for the removal of the component. Other components are preferably removably attached to the elongated member 27 , the hollow member 28 , or other components. Components may be removably attached by screws, nuts and bolts, clamps, pressing on, inserting and tightening one component threaded with male threads into another component threaded with female threads, or by other methods which allow for the removal of the component. One or more of the components that are described as removably attached may instead be affixed, and one or more of the components that are described as affixed may be removably attached, without departing from the spirit and scope of the present invention. Components may be made of fiberglass, carbon fiber, metal, plastic, wood, natural or synthetic fibers, or any other materials that are sufficiently strong to withstand the forces of use of the exercise system 26 by the operator without breaking or excessively bending, meaning bending to such a degree that slidable movement of the elongated member 27 relative to the hollow member 28 becomes difficult or impossible when the exercise system 26 is in use by the operator.
[0029] Handles 30 L and 30 R are affixed to a handle clamp 48 which is affixed to the handle end 41 of hollow member 28 , preferably by glue, welding, or other methods as known in the art. In another embodiment, handles 30 L and 30 R are affixed to handle clamp 48 , which is removably attached to handle end 41 of hollow member 28 by clamping, bolting, or other methods known in the art. Handle clamp 48 may further comprise two C-shaped sections joined together into the shape of a ring by gluing, welding, by bolts on each side, or by a hinge on one side and a bolt on the other side. The handles 30 L and 30 R receive force from the hands of the operator when the exercise system 26 is in use. Handles 30 L and 30 R also provide securing locations for at least one resistance band 54 . Resistance band 54 is preferably constructed of natural or synthetic rubber, and resembles a large common rubber band. In other embodiments, resistance band 54 is constructed of natural or synthetic rubber, and is comprised of a single strap with loops at each of its two ends of sufficient diameter to allow the resistance band 54 to be secured to securing locations such as handles 30 L or 30 R, band anchors 32 L, 32 R, 34 L, 34 R, 36 L, or 36 R, or foot board tube 38 . Resistance bands 54 may be constructed of different thicknesses and/or lengths to provide different levels of resistance. Band anchors 32 L, 32 R, 34 L, 34 R, 36 L, and 36 R are preferably rods which are affixed to elongated member 27 or hollow member 28 by glue, welding, or other methods as known in the art. In other embodiments, band anchors 32 L, 32 R, 34 L, 34 R, 36 L, and 36 R are hooks, studs, rings, bolts, or screws, or other similar members that are suitable for providing a securing location for at least one resistance band 54 . Affixed to the feet end 47 of hollow member 28 are band anchors 34 L and 34 R which provide securing locations for at least one resistance band 54 . Affixed to the head end 31 of the elongated member 27 are band anchors 32 L and 32 R which provide securing locations for at least one resistance band 54 .
[0030] Foot board tube 38 is inserted into foot board tube hole 57 drilled into foot board end 37 of elongated member 27 . The diameter of foot board hole 57 is slightly larger than the outside diameter of foot board tube 38 , such that when foot board tube 38 is positioned in foot board tube hole 57 , foot board tube 38 may freely rotate about its long axis, such that when exercise system 26 is in use the angle of the feet of the operator 52 , referring to the flexion or extension of the ankles of the operator 52 relative to the long axis of elongated member 27 , may be changed by the body movement of the operator 52 . Affixed to foot board tube 38 are band anchors 36 L and 36 R which provide securing locations for at least one resistance band 54 . Foot board tube 38 also provides securing locations for at least one resistance band 54 . Foot boards 40 L and 40 R are removably attached to foot board tube 38 preferably by inserting and tightening a plurality of footboard bolts 50 through a plurality of holes drilled in foot board tube 38 and a plurality of holes drilled in foot boards 40 L and 40 R The foot board system 35 comprises foot holders 44 L and 44 R and foot straps 42 L and 42 R. Foot straps 42 L and 42 R are removably attached to foot holders 44 L and 44 R, respectively, preferably by inserting and threading screws through foot straps 42 L and 42 R and into foot holders 44 L and 44 R. Foot holders 44 L and 44 R are removably attached to foot boards 40 L and 40 R, respectively, preferably by inserting and threading screws through foot holders 44 L and 44 R and into foot boards 40 L and 40 R, respectively. The length of the foot straps 42 L and 42 R may be adjusted by buckles, hook-and-loop fasteners, or other methods known in the art, for the use of exercise system 26 by different operators 52 with different sizes of feet. In addition, the length of the foot holders 44 L and 44 R may be adjusted by sliding them up or down on the foot boards 40 L and 40 R, respectively, and removably attaching them to the foot boards 40 L and 40 R, respectively, for use by different operators 52 with different sizes of feet. In another embodiment, instead of foot straps 42 L and 42 R and foot holders 44 L and 44 R, the foot board system may comprise a pair of cover foot stretchers and flexfoots (Concept 2, Morrisville, Vt.) each of which may be removably attached to foot boards 40 L and 40 R by inserting and tightening a plurality of foot board bolts 50 through holes cut or drilled through the cover foot stretchers and into foot boards 40 L and 40 R. In another embodiment, instead of foot straps 42 L and 42 R and foot holders 44 L and 44 R, the foot board system may comprise a pair of shoes each of which may be removably attached to foot boards 40 L and 40 R by inserting and tightening a plurality of foot board bolts 50 through holes cut or drilled through the soles of the shoes and into foot boards 40 L and 40 R End cap 46 is removably attached to the tip of the foot board end 37 of elongated member 27 . End cap 46 may be made of a durable and skid-resistant material such that it is suitable to be placed on a floor and/or against a wall so as to maintain the position of the tip of the foot board end 37 of elongated member 27 in place during use of the exercise system 26 .
[0031] At least one resistance band 54 is secured to two securing locations, one securing location on the elongated member 27 , and one securing location on the hollow member 28 . Securing a resistance band 54 to securing locations such as handles 30 L or 30 R, band anchors 32 L, 32 R, 34 L, 34 R, 36 L, or 36 R, or foot board tube 38 refers to a resistance band 54 being placed between two securing locations, one end of the resistance band 54 is looped around one securing location, and the other end of the resistance band 54 is looped around the other securing location, as illustrated in FIGS. 1 , 3 , and 3 b . The operator 52 may apply force to one or both of the handles 30 by one or both hands of the operator 52 in one direction, and at the same time apply force to the foot board system 35 by one or both feet of the operator 52 in the opposite direction, which causes movement of the hollow member 28 and the elongated member 27 relative to each other. The operator 52 also may position the tip of the foot board end 37 of the elongated member 27 on a floor and/or against a wall with the end cap 46 in contact with the wall and or floor so as to maintain the position of the tip of the foot board end 37 of elongated member 27 in place, as illustrated in FIG. 3 a , and apply force to one or both of the handles 30 L or 30 R by one or both hands of the operator 52 in the direction of the tip of the foot board end 37 of the elongated member 27 . Movement of the hollow member 28 relative to the elongated member 27 caused by the application of force by the operator 52 stretches a resistance band 54 , which creates resistance to the movement, thereby exercising, strengthening, and conditioning the operator 52 .
[0032] Referring to FIGS. 1 and 3 , the first configuration of the exercise system 26 is shown. In the first configuration, a resistance band 54 is secured to band anchors 32 R and 34 R. Also in the first configuration, a resistance band 54 may be secured to band anchors 32 L and 34 L, instead of or in addition to a resistance band 54 is secured to band anchors 32 R and 34 R. Also in the first configuration, more than one resistance band 54 may be secured to band anchors 32 R and 34 R, and/or band anchors 32 L and 34 L. To use the exercise system 26 in the first configuration, the operator applies force to the handles 30 L and 30 R by both hands in the direction of the distal end 49 of the exercise system 26 , and at the same time applies force to the foot board system 35 by both feet in the direction of the proximal end 39 of the exercise system 26 , which causes movement of the hollow member 28 and the elongated member 27 relative to each other. Movement of the hollow member 28 and the elongated member 27 relative to each other caused by the application of force by the operator stretches the resistance band 54 , which creates resistance to the movement, thereby exercising, strengthening, and conditioning the operator.
[0033] Referring to FIGS. 1 , 3 , and 3 a , also to use the exercise system 26 in the first configuration, the operator positions the tip of the foot board end 37 of elongated member 27 on a floor and/or against a wall, with the end cap 46 in contact with the wall and/or floor so as to maintain the position of the tip of the foot board end 37 of elongated member 27 in place, as illustrated in FIG. 3 a . The operator 52 then applies force to one or both of the handles 30 L or 30 R by one or both hands of the operator in the direction of the tip of the foot board end 37 of the elongated member 27 . Movement of the hollow member 28 relative to the elongated member 27 caused by the application of force by the operator stretches a resistance band 54 , which creates resistance to the movement, thereby exercising, strengthening, and conditioning the operator.
[0034] Referring to FIG. 3 b, the second configuration of the exercise system 26 is shown. In the second configuration, a resistance band 54 is secured to band anchor 36 L and to handle 30 L. Also in the second configuration, a resistance band 54 may be secured to band anchor 36 R and handle 30 R, instead of or in addition to a resistance band 54 is secured to band anchor 36 L and handle 30 L. Also in the first configuration, more than one resistance band 54 may be secured to band anchor 36 L and handle 30 L, and/or band anchor 36 R and handle 30 R. Also in the first configuration, one end of a resistance band 54 may be secured to foot board tube 38 instead of band anchors 36 L and/or 36 R. The operator applies force to the handles 30 L and 30 R by both hands in the direction of the proximal end 39 of the exercise system 26 , and at the same time applies force to the foot board system 35 by both feet in the direction of the distal end 49 of the exercise system 26 , which causes movement of the hollow member 28 and the elongated member 27 relative to each other. Movement of the hollow member 28 and the elongated member 27 relative to each other caused by the application of force by the operator stretches the resistance band 54 , which creates resistance to the movement, thereby exercising, strengthening, and conditioning the operator.
Method of Use
[0035] The exercise system 26 of the present inventions is used for exercising the muscles of the extremities and the trunk and core, including the neck, chest, abdomen, and back. Methods of using the exercise system 26 , or exercises, are performed standing, lying prone, lying supine, and lying on one side. Exercises described or illustrated using one arm of a particular side of the body are also performed using the arm of the opposite side of the body. Exercises described or illustrated using one leg of a particular side of the body are also performed using the leg of the opposite side of the body. Exercises are performed one or more times at the option of the operator 52 , and in any order chosen by the operator 52 , for strengthening and conditioning. Exercises using the exercise system 26 in the first configuration are shown in FIGS. 4-10 and 15 - 25 . Exercises using the exercise system 26 in the second configuration are shown in FIGS. 11-14 .
[0036] Exercises are performed by the operator 52 lying supine and using the exercise system 26 in the first configuration. At least one resistance band 54 is secured to one or more band anchors 32 L and/or 32 R and to band anchors 34 L and/or 32 R. The operator then performs one or more of the following exercises as shown in FIGS. 4-10 and 15 - 25 .
[0037] As shown in FIG. 4 a , both feet of the operator 52 are placed into foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator 52 then places pad 56 on their abdomen to raise the exercise system 26 off their abdomen. Pad 56 may be constructed of cork, rubber, and/or any other natural or synthetic material or cloth that is strong and stiff enough to raise the exercise system 26 off the abdomen and soft enough to cushion the contact of the exercise system 26 with the abdomen while exercises are being performed. The operator straightens the legs, raises both hands over the head, and grasps handles 30 L and 30 R. As shown in FIG. 4 b , operator 52 simultaneously pulls foot boards 40 toward the proximal end 39 using the legs while holding handles 30 L and 30 R in place over the head using the arms. The exercise shown in FIG. 4 is also performed with only one foot of the operator 52 secured to one of the foot holders 44 L or 44 R. The exercise shown in FIG. 4 may also be performed without pad 56 .
[0038] As shown in FIG. 5 a , both feet of the operator 52 are placed into the foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator 52 then places pad 56 on their abdomen to raise the exercise system 26 off their abdomen. The operator straightens the legs, raises both hands over the head, and grasps handles 30 L and 30 R. As shown in FIG. 5 b , operator 52 simultaneously pulls foot boards 40 toward the proximal end 39 using the legs and pulls the handles 30 L and 30 R toward the distal end 49 using the arms. The exercise shown in FIG. 5 may also be performed without pad 56 .
[0039] As shown in FIG. 6 a , the left foot of the operator 52 is placed into foot holder 44 L and secured by tightening foot strap 42 L. The operator 52 then places pad 56 on their abdomen to raise the exercise system 26 off their abdomen. The operator bends the left leg to about 80-100 degrees of flexion, preferably about 90 degree of flexion, raises the right hand over the head, and grasps handle 30 R. As shown in FIG. 6 b , operator 52 simultaneously pulls handle 30 R toward the distal end 49 using the right arm and holds foot boards 40 in place using the left leg. The exercise shown in FIG. 6 is also performed with the opposite extremities, such that the right foot of the operator 52 is placed into foot holder 44 R and secured by tightening foot strap 42 R, the operator raises the left hand over the head, grasps handle 30 L, and simultaneously pulls handle 30 L toward the distal end 49 using the left arm while holding foot boards 40 in place using the right leg. The exercise shown in FIG. 6 may also be performed without pad 56 .
[0040] As shown in FIG. 7 a , the left foot of the operator 52 is placed into foot holder 44 L and secured by tightening foot strap 42 L. The operator 52 then places pad 56 on their abdomen to raise the exercise system 26 off their abdomen. The operator straightens the left leg, raises the right hand over the head, and grasps handle 30 R. As shown in FIG. 7 b , operator 52 simultaneously pulls foot boards 40 toward the proximal end 39 using the left leg and pulls handle 30 R toward the distal end 49 using the right arm. The exercise shown in FIG. 7 is also performed with the opposite extremities, such that the right foot of the operator 52 is placed into foot holder 44 R and secured by tightening foot strap 42 R, the operator raises the left hand over the head, grasps handle 30 L, and simultaneously pulls foot boards 40 toward the proximal end 39 using the right leg and pulls handle 30 L toward the distal end 49 using the left arm. The exercise shown in FIG. 7 may also be performed without pad 56 .
[0041] As shown in FIG. 8 a , the left foot of the operator 52 is placed into foot holder 44 L and secured by tightening foot strap 42 L. The operator 52 then places pad 56 on their abdomen to raise the exercise system 26 off their abdomen. The operator straightens the left leg, raises the right hand over the head, and grasps handle 30 R. As shown in FIG. 8 b , operator 52 simultaneously pulls foot boards 40 toward the proximal end 39 using the left leg and holds handle 30 R in place using the right arm. The exercise shown in FIG. 7 is also performed with the opposite extremities, such that the right foot of the operator 52 is placed into foot holder 44 R and secured by tightening foot strap 42 R, the operator raises the left hand over the head, grasps handle 30 L, and simultaneously pulls foot boards 40 toward the proximal end 39 using the right leg and holds handle 30 L in place using the left arm and. The exercise shown in FIG. 8 may also be performed without pad 56 .
[0042] As shown in FIG. 10 a , both feet of the operator 52 are placed into foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator 52 then places pad 56 on their abdomen to raise the exercise system 26 off their abdomen. The operator bends both legs to about 80-100 degrees of flexion, preferably about 90 degree of flexion, raises both hands over the head, and grasps handles 30 L and 30 R. As shown in FIG. 10 b , operator 52 simultaneously pulls the foot boards 40 toward the proximal end 39 by flexing the feet at the ankles but not otherwise moving the legs while holding handles 30 L and 30 R in place over the head using the arms. The exercise shown in FIG. 10 is also performed with only one foot of the operator 52 secured to one of the foot holders 44 L or 44 R. The exercise shown in FIG. 10 may also be performed without pad 56 .
[0043] As shown in FIG. 15 a , both feet of the operator 52 are placed into foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator 52 presses the foot boards 40 to the floor so that the distal end 49 is in contact with the floor, grasps handles 30 L and 30 R, and positions the hands and handles 30 L and 30 R to about the level of the chest. As shown in FIG. 15 b , operator 52 simultaneously pulls the handles 30 L and 30 R toward the distal end 49 using the arms and holds the foot boards 40 in place and in contact with the floor using the legs. The exercise shown in FIG. 15 is also performed with only one arm of the operator 52 grasping one of the handles 30 L or 30 R and pulling that handle 30 L or 30 R toward the distal end 49 .
[0044] Exercises are also performed by the operator 52 lying prone and using the exercise system 26 in the first configuration. At least one resistance band 54 is secured to one or more band anchors 32 L and/or 32 R and to band anchors 34 L and/or 32 R. The operator then performs one or more of the following exercise as shown in FIG. 9 . As shown in FIG. 9 a , both feet of the operator 52 are placed into foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator straightens the legs, raises both hands over the head, and grasps one of the handles 30 L or 30 R. As shown in FIG. 9 b , operator 52 simultaneously pulls the foot boards 40 L and 40 R toward the proximal end 39 using the legs while holding handle 30 L or 30 R in place over the head using the arms. The exercise shown in FIG. 9 is also performed with only one foot of the operator 52 secured to one of the foot holders 44 L or 44 R.
[0045] Exercises also are performed by the operator 52 lying supine and using the exercise system 26 in the second configuration. At least one resistance band 54 is secured to one or more handles 30 L and/or 30 R and to band anchors 36 L and/or 36 R. In the alternative, at least one resistance band 54 is secured to one or more handles 30 L and/or 30 R and to foot board tube 38 . The operator then performs one or more of the following exercises as shown in FIGS. 11-14 .
[0046] As shown in FIG. 11 a, both feet of the operator 52 are placed into foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator 52 raises both hands to about the level of the face, and grasps handles 30 L and 30 R. As shown in FIG. 11 b , operator 52 simultaneously pushes the foot boards 40 toward the distal end 49 using the legs and holds the handles 30 L and 30 R in place over in front of the face using the arms.
[0047] As shown in FIG. 12 a , both feet of the operator 52 are placed into foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator 52 raises both hands to about the level of the face, and grasps handles 30 L and 30 R. As shown in FIG. 12 b , operator 52 simultaneously pushes the foot boards 40 toward the distal end 49 using the legs and pushes the handles 30 L and 30 R toward the proximal end 39 using the arms.
[0048] As shown in FIG. 13 a, both feet of the operator 52 are placed into foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator 52 raises both hands to about the level of the face, and grasps handles 30 L and 30 R. As shown in FIG. 13 b , operator 52 simultaneously pushes the handles 30 L and 30 R toward the proximal end 39 using the arms and holds the foot boards 40 in place using the legs.
[0049] As shown in FIG. 14 a , both feet of the operator 52 are placed into foot holders 44 L and 44 R and secured by tightening foot straps 42 L and 42 R. The operator 52 presses the foot boards 40 to the floor so that the distal end 49 is in contact with the floor, grasps handles 30 L and 30 R, and positions the hands and handles 30 L and 30 R to about the level of the neck. As shown in FIG. 14 b , operator 52 simultaneously pushes the handles 30 L and 30 R toward the proximal end 39 using the arms and holds the foot boards 40 in place and in contact with the floor using the legs. The exercise shown in FIG. 14 is also performed with only one arm of the operator 52 grasping one of the handles 30 L or 30 R and pushing that handle 30 L or 30 R toward the proximal end 39 .
[0050] Exercises are also performed by the operator 52 standing and using the exercise system 26 in the first configuration. At least one resistance band 54 is secured to one or more band anchors 32 L and/or 32 R and to band anchors 34 L and/or 32 R. The operator then performs one or more of the following exercises as shown in FIGS. 16-25 .
[0051] As shown in FIG. 16 a , the operator 52 places the exercise system 26 between the legs, positions the exercise system 26 at an angle with the floor as shown in FIG. 16 a with the distal end 49 in contact with a wall and/or floor, as also depicted in FIG. 3 a , grasps handles 30 L and 30 R, and stands and maintains the back in an upright position. As shown in FIG. 16 b , operator 52 simultaneously pulls the handles 30 L and 30 R toward the distal end 49 using the arms and holds the distal end 49 in position against the floor and/or wall.
[0052] As shown in FIG. 17 a , the operator 52 places the exercise system 26 between the legs, positions the exercise system 26 at an angle with the floor as shown in FIG. 17 a with the distal end 49 against a wall and/or floor, as also depicted in FIG. 3 a , grasps handles 30 L and 30 R, stands and bends the upper body forward at the waist, and maintains the position of the upper body bent forward at the waist. As shown in FIG. 17 b , operator 52 simultaneously pulls the handles 30 L and 30 R toward the distal end 49 and the wall and/or floor using the arms and holds the distal end 49 in position against the floor and/or wall.
[0053] As shown in FIG. 18 a , the operator 52 places the exercise system 26 in front of the body, positions the exercise system 26 at an angle with the floor as shown in FIG. 18 a with the distal end 49 in contact with a wall and/or floor, as also depicted in FIG. 3 a , grasps handles 30 L and 30 R, and stands and maintains the back in an upright position. As shown in FIG. 18 b , operator 52 simultaneously pulls the handles 30 L and 30 R across the front of the body toward the distal end 49 using the arms and holds the distal end 49 in position against the floor and/or wall.
[0054] As shown in FIG. 19 a , the operator 52 places the exercise system 26 in front of the body, positions the distal end 49 between the feet and the exercise system 26 in a vertical orientation with the proximal end 39 directed toward the ceiling and the distal end 49 in contact with the floor, stands upright, raises both hands over the head, and grasps handles 30 L and 30 R. As shown in FIG. 19 b , operator 52 simultaneously pulls the handles 30 L and 30 R toward the floor and the distal end 49 by flexing the arms and the legs and bending the body into a squatting position with the legs and arms bent and holds the distal end 49 in position against the floor.
[0055] As shown in FIG. 20 a , the operator 52 places the exercise system 26 in front of the body, positions the distal end 49 between the feet and the exercise system 26 in a vertical orientation with the proximal end 39 directed toward the ceiling and the distal end 49 in contact with the floor, stands upright, raises both hands over the head, and grasps handles 30 L and 30 R. As shown in FIG. 20 b , operator 52 simultaneously pulls the handles 30 L and 30 R toward the floor and the distal end 49 by flexing the legs without bending the arms and bending the body into a squatting position with the legs bent and the arms straight and holds the distal end 49 in position against the floor.
[0056] As shown in FIG. 21 a, the operator 52 places the exercise system 26 in front of the body, positions the distal end 49 between the feet and the exercise system 26 in a vertical orientation with the proximal end 39 directed toward the ceiling and the distal end 49 in contact with the floor, stands upright, raises both hands over the head, grasps handles 30 L and 30 R, and first pulls the handles 30 L and 30 R toward the floor and the distal end 49 by flexing the legs without bending the arms and bending the body into a squatting position. As shown in FIG. 21 b , operator 52 then flexes the arms and pulls the handles 30 L and 30 R closer to the distal end 49 and floor, and simultaneously holds the distal end 49 in position against the floor.
[0057] As shown in FIG. 22 a , the operator 52 places the exercise system 26 on the left side of the body, places the left foot in one of the foot holders 44 L or 44 R and secures it by tightening foot strap 42 L or 42 R, positions the exercise system 26 at an angle with the floor as shown in FIG. 22 with the distal end 49 in contact with the floor, or with the distal end 49 against a wall and/or floor as depicted in FIG. 3 a , grasps handles 30 L and 30 R, and stands on the right leg and maintains the back in an upright position. As shown in FIG. 22 b , operator 52 simultaneously pulls the handles 30 L and 30 R toward the body and toward the distal end 49 using the arms and holds the distal end 49 in position against the floor. The exercise shown in FIG. 22 is also performed with the opposite extremities, such that the operator 52 places the exercise system 26 on the right side of the body, places the right foot in one of the foot holders 44 L or 44 R and secures it by tightening foot strap 42 L or 42 R, positions the exercise system 26 at an angle with the floor as shown in FIG. 22 with the distal end 49 in contact with the floor, grasps handles 30 L and 30 R, stands on the left leg and maintains the back in an upright position, and simultaneously pulls the handles 30 L and 30 R toward the body and toward the distal end 49 using the arms and holds the distal end 49 in position against the floor.
[0058] As shown in FIG. 23 a , the operator 52 places the exercise system 26 on the left side of the body, places the left foot in one of the foot holders 44 L or 44 R and secures it by tightening foot strap 42 L or 42 R, positions the exercise system 26 at an angle with the floor as shown in FIG. 23 a with the distal end 49 in contact with the floor, or with the distal end 49 against a wall and/or floor as depicted in FIG. 3 a , grasps handles 30 L and 30 R, and stands on the right leg and maintains the back in an upright position. As shown in FIG. 23 b , operator 52 simultaneously pulls the handles 30 L and 30 R toward the body and toward the distal end 49 using the arms and pulls the foot boards 40 up off the floor toward the proximal end 39 using the left leg and remains standing on the right leg. The exercise shown in FIG. 23 is also performed with the opposite extremities, such that the operator 52 places the exercise system 26 on the right side of the body, places the right foot in one of the foot holders 44 L or 44 R and secures it by tightening foot strap 42 L or 42 R, positions the exercise system 26 at an angle with the floor as shown in FIG. 23 with the distal end 49 in contact with the floor, grasps handles 30 L and 30 R, stands on the left leg and maintains the back in an upright position, and simultaneously pulls the handles 30 L and 30 R toward the body and toward the distal end 49 using the arms and pulls the foot boards 40 up off the floor toward the proximal end 39 using the right leg and remains standing on the left leg.
[0059] As shown in FIG. 24 a , the operator 52 places the exercise system 26 on the left side of the body, places the left foot in one of the foot holders 44 L or 44 R and secures it by tightening foot strap 42 L or 42 R, positions the exercise system 26 at an angle with the floor as shown in FIG. 24 a with the distal end 49 in contact with the floor, or with the distal end 49 against a wall and/or floor as depicted in FIG. 3 a , grasps handles 30 L and 30 R, and stands on the right leg and maintains the back in an upright position. As shown in FIG. 24 b , operator 52 simultaneously pulls the foot boards 40 up off the floor toward the proximal end 39 using the left leg and remains standing on the right leg and holds the handles 30 L and 30 R in place using the arms. The exercise shown in FIG. 24 is also performed with the opposite extremities, such that the operator 52 places the exercise system 26 on the right side of the body, places the right foot in one of the foot holders 44 L or 44 R and secures it by tightening foot strap 42 L or 42 R, positions the exercise system 26 at an angle with the floor as shown in FIG. 24 with the distal end 49 in contact with the floor, grasps handles 30 L and 30 R, stands on the left leg and maintains the back in an upright position, and simultaneously pulls the foot boards 40 up off the floor toward the proximal end 39 using the right leg and remains standing on the left leg and holds the handles 30 L and 30 R in place using the arms.
[0060] As shown in FIG. 25 a , the operator 52 places the exercise system 26 in front of the body, positions the exercise system 26 at an angle with the floor as shown in FIG. 25 a with the distal end 49 in contact with a wall and/or floor, as also depicted in FIG. 3 a , positions the proximal end 39 in contact with the chest, grasps handles 30 L and 30 R, stands and leans forward toward the exercise system 26 , and maintains the back and legs in a straight position. As shown in FIG. 25 b , operator 52 simultaneously pushes the handles 30 L and 30 R toward the distal end 49 using the arms and holds the distal end 49 in position against the floor and/or wall. The exercise shown in FIG. 25 is also performed with the exercise system 26 parallel to the floor with the distal end 49 in contact with the wall at a location on the wall above the floor.
[0061] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that the invention disclosed herein is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
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An exercise device and methods for performing physical exercise that improve strength, conditioning, and flexibility of an operator in a functional way using multiple body positions and exercising multiple muscle groups while keeping the spine in a safe and natural position, being simple to manufacture and use, and being compact and portable. The exercise device includes an elongated member, a hollow member, handles, a foot board system, and at least one resistance band. A resistance band is secured to the elongated member and the hollow member, and slidable movement of the hollow member and the elongated member relative to each other by the operator stretches a resistance band, which creates resistance to the movement, thereby exercising, strengthening, and conditioning the operator. The operator may use the exercise device in a number of configurations to perform a number of exercises in a number of body positions.
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GOVERNMENT RIGHTS
This invention was made with government support under Contract No. F33615-03-D-2354-0009 awarded by the United States Air Force. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
Materials used in the turbine section of a gas turbine engine may be subjected to temperatures that are above the melting point of those materials. To operate under such high temperatures, the parts using those materials must be internally cooled. Turbine airfoils, for example, use internal cores that form hollow passages within the airfoils. In high heat load applications, trip strips may be used within these passages to further enhance convective cooling.
It is typical in the art, for a ceramic material to be injected into a metal die and then fired to form desired core passages of a turbine airfoil. Slots are built into the die into which a RMC (Refractory Metal Core) is inserted. The RMC is stamped or cut out and then put into form dies to achieve the desired 3D shapes. The RMC is then attached into the slots in the ceramic core. At this point, the sacrificial die is prepared for further processing such as a lost wax process, investment casting or the like.
SUMMARY OF THE INVENTION
According to an exemplar, a core for creating an airfoil has body made from a ceramic material. The body has an outer dimension, a slot extending through the outer dimension and into the body for receiving an insert, the slot disposed at an angle to the outer dimension, and a trip strip having a first portion disposed in the outer dimension. The first portion is in register with the slot wherein a constant dimension is maintained between the first portion and the slot along a length of the slot and wherein said first portion tapers towards said outer dimension to facilitate the manufacturability of the ceramic core.
According to a further exemplar, a core die for creating a core has a first section, a second section mating with the first section, and an insert for creating a slot. The first section and the second section define a body having an outer dimension, the insert disposed at an angle to the outer dimension, and trip strips having a first portion disposed in the second section, the first portion in register with the insert wherein a constant dimension such as minimum thickness is maintained between the first portion and the insert along a length of the insert and wherein said first portion tapers towards said outer dimension.
According to a further exemplar, an airfoil has a body having an inner passageway for cooling the body, trip strips disposed within the inner passageway, the trip strips tapering into an area requiring increased cooling.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side, perspective view of a ceramic core including an RMC insert.
FIG. 2 is a cut-away view of the core of FIG. 1 , taken along the line 2 - 2 , shown in a ceramic core mold.
FIG. 3 is a cut-away view of the core of FIG. 1 taken along the line 3 - 3 .
FIG. 4 is a partial view of the core die, which is a negative of the core.
FIG. 5 is a partial, cross-sectional view of a turbine blade made from the ceramic core and RMC insert of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a sacrificial core assembly 10 used in making a turbine blade 130 (see FIG. 5 ). The sacrificial core assembly 10 has a ceramic core 15 and an RMC 20 , also known as a Refractory Metal Core, that acts as an insert and is attached into a slot 25 (see the ceramic core 15 shown in die 90 in FIG. 2 and isolated in FIG. 3 ) in the ceramic core 15 . The ceramic core 15 has a plurality of trip strips 65 that provide enhanced heat transfer to cool a turbine blade 130 (see FIG. 5 ). The ceramic core 15 has an outer dimension including a suction side 35 , a pressure side 40 , a trailing edge 45 , a leading edge 50 and slot 25 (see FIGS. 2 and 3 ) for RMC 20 to be inserted. The RMC may be secured in the slot in several ways including gluing or mechanical means, such as clips or the like (not shown).
Referring to FIGS. 2 and 3 , a plurality of trip strips 65 extend along a length of the suction side 35 of the ceramic core 15 . The trip strips 65 are shown adjacent the trailing edge 45 of the suction side 35 but may be placed anywhere heating loads in or on the turbine blade 130 make additional cooling desirable.
This description shows trip strips 65 placed towards the trailing edge 45 of the ceramic core 15 , while still allowing for adequate dimension D, such as thickness or depth or the like, from the slot 25 to maintain manufacturability as will be discussed herein. Without the placement of the tapered trip strip portion 70 , trip strip coverage is reduced to accommodate minimum ceramic core thickness requirements for manufacturing and required cooling may not be provided. Trip strips 65 may be of any size, shape and configuration (straight, chevron—see FIG. 4 , etc.) as may be required to provide cooling. Although this disclosure shows the trip strips 65 on the suction side 35 , all the same concepts could be used with trip strips on either the suction side 35 or pressure side 40 , depending on the cooling requirements of the particular part.
Referring now to FIG. 4 , the negative features to produce trips strips 65 of a core die 90 are shown. Each trip strip 65 has a portion 75 , which is elongated and has a rectangular cross-section. The portion 75 , which may have an angled part 75 A attached thereto to form a chevron, is attached to a tapered portion 70 . Both the portion 75 and tapered portion 70 are disposed on a wall 80 , which is the same surface on a finished blade (see FIG. 5 ). Each tapered portion 70 tapers towards the wall portion 80 from the portion 75 A. The tops 81 and 81 A are in plane but the top 70 A of portion 70 tapers downwardly out of plane with tops 81 and 81 A of portions 75 and 75 A thereby creating taper portion 70 . One of ordinary skill in the art will recognize that the tapered portion 70 may disposed on any portion of the trip strip 65 to accommodate an area 125 between the slot 25 and the wall 70 A (see FIG. 2 ) as will be discussed hereinbelow and as may be required by a particular design. Taper portion 70 also need not be attached to a portion 75 to be functional herein. Similarly, both the taper portion 70 and the portion 75 may have other cross-sectional dimensions and such other shapes are contemplated herein.
Referring now to FIG. 2 and the core die 90 shown in FIG. 4 , the ceramic core 15 is shown along lines 2 - 2 . The ceramic core 15 is formed in a core die 90 having a first half 95 , a second half 100 and a manufacturing insert 105 that is removably attached to the respective core die 90 halves 95 and 100 or sections, as is known in the art. The ceramic core 15 shows portions 75 A of the trip strips 65 and the tapered portions 70 of the trip strips 65 . The trip strips 65 come out of the core die 90 as shown in FIG. 3 .
Referring now to FIG. 2 , the core die 90 includes the insert 105 and ceramic material 120 is inserted into the core die 90 . The ceramic material flows to all areas of the core die 90 , however, areas in which the ceramic material 120 flows must have a dimension such as minimum thickness to allow the material to fill the core die 90 as well as provide strength in the finished ceramic core. For instance the area 125 between the tapered portion 70 of the trip strip 65 and the slot 105 has a thickness D, which is dependent on the type of ceramic material used, to allow the ceramic material 120 to fill the area 125 to the trailing edge 45 . It should be noted that the dimension D may vary for given ceramic materials.
By recognizing the need for a thickness D, the trip strip portion 70 may be tapered while maintaining the thickness D to allow for the tapered portion 70 to extend closer to trailing edges of the ceramic core 15 . If the thickness D is not maintained, the ceramic material 120 may not flow to the trailing edge 45 or breakage in the finished ceramic core may be experienced. The trip strip portion 70 tapers in register with the shape of the slot 25 so that the thickness D is maintained in area 125 .
Referring to FIGS. 2 , 3 and 5 , the ceramic core 15 is removed from the core die 90 and the insert 105 is removed from the ceramic core 15 . The RMC 20 is attached into slot 25 . The ceramic core 15 and the RMC are sacrificed, as is known in the art, to make the turbine blade 130 shown partially in FIG. 5 . The RMC 20 and ceramic core 15 become shaped opening 135 (of the finished part—see FIG. 5 ) and the trip strips 65 , including the tapered portion 70 and portions 75 are distributed along the outer edges of the opening 135 . Because of the tapered portions 70 of surface the trip strips 65 , the trip strips 65 can now be distributed to a greater area of the shaped opening 135 .
Typically, trip strips 65 can be placed anywhere within the turbine blade 130 . However, when forming the ceramic core 15 , there must be enough room in the core die 90 to allow for the manufacturability of the ceramic core 15 and a certain dimension such as minimum thickness D must be allowed. Prior art cores have not been designed to accommodate trip strips 65 where they would be most useful. This disclosure allows for the additional of trip strips 65 in areas 135 not previous thought as suitable for trip strips.
Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.
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A core for creating an airfoil has a ceramic material that forms a body. The body has an outer dimension, a slot extending through the outer dimension and into the body for receiving an insert, the slot disposed at an angle to the outer dimension, and a trip strip having a first portion disposed in the outer dimension. The first portion is in register with the slot wherein a constant dimension such as minimum thickness is maintained between the trip strip and the slot along a length of the slot and wherein said first portion tapers towards said outer dimension.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C. §120 of International Application No. PCT/IB00/00873, filed May 19, 2000, which further claims the benefit under 35 U.S.C. §365(c) of Italian Application No. MI99A 001176, filed May 27, 1999.
BACKGROUND OF THE INVENTION
The subject of the present invention is an article capable of deflecting electromagnetic fields coming from external sources. In particular, it refers to a fabric which, associated to an electronic circuit, is able to suppress and deflect electromagnetic fields in the surrounding environment This type of fabric, associated to the electronic circuit, is particularly suitable for the production of articles commonly used in the domestic sphere, such as blankets for beds, tablecloths, carpets and curtains, as well as fabric for upholstery and furnishings, such as for picture frames, sofas, armchairs, and the like.
The need to produce this type of fabric has arisen recently precisely because the amount of electromagnetic waves to which the human body is subjected has increased considerably.
In the domestic sphere we are continuously bombarded by electromagnetic fields coming from radio transmitters and receivers, which spread electromagnetic waves in the radio-frequency range, from liquid-crystal displays of various kinds of electronic equipment, and above all from the phosphors of television screens or from computer monitors which transmit electromagnetic waves at a frequency concentrated in the 16-100 kHz frequency range.
In addition, frequently houses are built near high-tension lines supplying electric power, which emit electromagnetic radiation.
Furthermore, there has recently been a marked reinforcement of the GSM network for cell telephones; as a result, the use of cellphones has spread considerably also in the household environment, and this too is a source of emission of electromagnetic waves, in the 900-1800 MHz frequency range.
Recent medical studies have demonstrated that any charge of an electric or electromagnetic nature absorbed by the human body is prejudicial to the cellular balance of the chondriome. The chondriome is a cell apparatus consisting of the complex of chondriosomes, which are corpuscles that are found in the cytoplasm of most cells in the form of grains, filaments and rods and are thought to function in physiology of the cell.
Initially, our organism reacts by compensating for the cellular imbalance in the chondriome caused by electromagnetic radiation, but in the long run this imbalance is no longer compensated for, and this causes poor cell physiology with consequent harmful effects on human health.
The patent application MI97A 0026384 filed by the present applicant, as yet not published, describes a garment for deflecting electromagnetic fields, which has the purpose of protecting the user from the electromagnetic fields surrounding him. The above application, however, is limited only to a garment that can be worn by the user.
SUMMARY OF THE INVENTION
The purpose of the invention is to overcome such drawbacks by providing an article which is easy to make and is able to deflect and absorb the electromagnetic fields present in an environment.
This purpose is achieved, in accordance with the invention, by means of an article having the characteristics listed in the annexed independent claim 1.
Preferred embodiments of the invention appear from the dependent claims.
After repeated tests, the inventor has found that the fabric used for the garment of the patent application MI97A 0026384, connected to an appropriate electronic circuit, could be used for the production of articles of everyday household use for the suppression, deflection, absorption and abatement of the electromagnetic fields present in an environment. Consequently, it was possible to obtain a purification of the premises in which the above tests were conducted.
The article according to the invention is obtained by means of a meshed conductive fabric connected to an electronic circuit. Said conductive fabric absorbs electromagnetic fields and conveys them towards the electronic circuit, where they are dissipated by the Joule effect. The article can act as a sort of Faraday cage by discharging the electromagnetic signal to earth. Clearly, the earth is to be understood as a virtual earth, since earthing of the circuit is achieved by means of its connection to a strip made of conductive material, functioning as a dissipator.
As electronic circuit any parallel resonator may be used.
A detector of electromagnetic fields may be connected to the electronic circuit, which signals, by means of a LED, the presence of electromagnetic fields in the environment. In this way, the user knows when the article according to the invention is absorbing and deflecting an electromagnetic field.
Further characteristics of the invention will emerge more clearly from the ensuing detailed description, which refers to embodiments given purely to provide non-limiting examples, illustrated in the attached drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a plan view of a blanket according to the invention;
FIG. 2 shows a plan view of a detail of a fabric of the blanket of FIG. 1;
FIG. 3 shows a plan view of a detail of the weft of the border of the blanket illustrated in FIG. 1;
FIG. 4 shows the electric diagram of an electronic circuit according to the invention;
FIG. 5A shows a schematic view of an anechoic chamber for measuring attenuation of the electromagnetic field performed on the article according to the invention at a frequency in the 30-100 MHz range;
FIG. 5B shows a schematic view of a semi-anechoic chamber for measuring attenuation of the electromagnetic field performed on the article according to the invention at a frequency in the 1-2 GHz range;
FIGS. 6-9 show diagrams of percentage attenuation of the electromagnetic field in the 30-100 MHz frequency range;
FIGS. 10 and 11 show diagrams of electromagnetic field in the 1-2 GHz frequency range;
FIGS. 12 and 13 show diagrams of percentage attenuation of the electromagnetic field in the 1-2 GHz frequency range.
The article according to the invention will now be described with the aid of the above figures.
DETAILED DESCRIPTION OF THE INVENTION
Purely to provide an example, reference is made to a blanket 1 that deflects electromagnetic fields, the blanket 1 consisting of a conductive, meshed, dry fabric 2 . Interwoven in the weft of said fabric 2 are parallel filaments 3 made of conductive material, which preferably may be tungsten and carbon. Said filaments 3 are able to conduct the electromagnetic fields that concentrate on the blanket 1 .
The perimeter of the blanket 1 is bordered by a fabric 4 with a criss-cross grid. The fabric 4 has a criss-cross grid of filaments 5 , and these filaments 5 must be made of conductive material, preferably tungsten and carbon. The meshed fabric 4 is arranged on the border of the blanket 1 and is folded back, the said meshed fabric 4 having a weft that is thicker and more closely knit than the fabric 2 and having the function of closing the conductive circuit created in the blanket 1 .
In the area of said border, the blanket 1 may be covered with a material which may even not be conductive; purely as an example, wool can be used as material for covering the border.
An electronic circuit 10 is connected by means of a conductor wire 11 to the fabric 4 bordering the blanket 1 . Earthing of the circuit is obtained by means of a strip 12 made of conductive material, preferably copper. The strip 12 hangs from the blanket 1 , so as to be able to discharge the electromagnetic field present on the blanket. The circuit 10 can be positioned in a special housing made inside the blanket 1 so as not to be visible.
Also connected to the border 4 of the blanket there is provided a detector 20 of electromagnetic fields. The detector 20 may be a solid-state detector of the type readily available commercially. The detector 20 is connected to a light source 21 , for instance a LED, for emitting a light signal when the blanket 1 is absorbing an electromagnetic field. Instead of the LED 1 it is also clearly possible to provide an acoustic signalling device.
The electronic circuit 10 may be any parallel-resonator circuit with a specific cut-off frequency and frequency of resonance. Said circuit 10 must be able to dissipate, by the Joule effect, the electromagnetic signal coming from the blanket 1 and must be able to cut off the signals above its own cut-off frequency.
FIG. 4 shows a possible embodiment of the electrical diagram of the circuit 10 . Between the fabric 4 of the border and the parallel-resonator circuit is set a coupling capacitor 13 .
The parallel resonator is represented by the connection in parallel of an inductance coil 14 and a resistor 19 .
The resistor 19 must preferably be selected with a low resistance value, approximately 100Ω, so that the power dissipated by said resistor 19 is very small, i.e., of the order of nanojoule/s. This leads to a minimal increase in temperature, quantifiable at approximately half a degree centigrade.
The coupling capacitor 13 may be selected at a capacitance value of approximately 2 pF. The inductance coil 14 of the parallel resonator may be selected at an inductance value of 10 μH.
The foregoing example of application has been provided for a blanket; it, nevertheless, remains valid also for other articles, such as curtains, carpets, tablecloths, picture frames, and fabrics for upholstery and furnishings in general.
Described below is the experiment for measuring attenuation of the electromagnetic fields acting on the article according to the invention.
To prevent possible reflection of the electromagnetic waves, the above experiment was conducted inside an anechoic chamber 50 according to the set-up of FIG. 5 A. An insulating support 30 was positioned in the anechoic chamber 50 , the said support 30 being designed to support the article 1 . The support 30 also supported an isotropic detector 32 designed to detect an electric field value. In the anechoic chamber 50 , at a distance of one meter from the support 30 , an antenna 31 was positioned to irradiate a known electromagnetic field generated by a field generator 33 . The generator 33 was a generator of a programmable type generating electric fields in the radiofrequency range.
The value of percentage attenuation of the electromagnetic field was obtained applying the formula:
% Att.=(1−( E f /E i ))*100 (1)
where E f is the final electric field value measured by the detector 32 inside the article 1 , and E i is the initial value of the electric field measured by the detector 32 in the absence of the article 1 .
In the 30 MHz to 1 GHz frequency range, the electric field E i detected by the isotropic probe 32 positioned in the support 30 without the article 1 was measured.
Subsequently, the electric field E f detected by the same isotropic probe 32 with the article 1 positioned on the support 30 was measured, keeping the positions of the detector 32 and the antenna 31 and the distance between them unaltered and keeping the same level of irradiated signal.
The tests were repeated with the antenna 31 set both in vertical bias and in horizontal bias; for both biases, the percentage attenuation of the article 1 both on the front side and on the rear side was ascertained.
The values of the electric fields E i and E f were measured for discrete frequencies, and applying the formula (1) the graphs of FIGS. 6-9 were obtained.
As shown in FIGS. 6 and 7, for a vertical bias, both on the front side and on the rear side of the article 1 there is a mean attenuation of approximately 65% with attenuation peaks of approximately 85% in the region of the 244 MHz frequency range.
As shown in FIGS. 8 and 9, for a horizontal bias, there is an attenuation of approximately 10% both on the front side and on the rear side of the article.
To carry out tests in the 1-2 GHz frequency range, the arrangement illustrated in FIG. 5B was used. In this case two microwave antennas were used, one as transmitter 61 and the other as receiver 62 , set at the same height and at a distance of one meter apart. A generator 63 of a signal in the microwave range was connected to the transmitter antenna 61 and, by means of a synchronizer 64 , was synchronized with the receiver antenna 62 . The measurement was performed, positioning the support 30 in a semi-anechoic chamber; instead, the receiver 62 and the transmitter 61 were positioned outside the semi-anechoic chamber.
For a vertical bias of antennas, it was possible to plot a graph of the electric field (expressed in dBμV) measured by the receiver antenna 62 , in the 1-2 GHz frequency range.
FIG. 10 shows the plot of the electric field 80 in the absence of the article 1 , and the plot of the electric field 81 attenuated on the front side of the article 1 .
FIG. 11 shows the plot of the electric field 80 in the absence of the article 1 , and the plot of the electric field 82 attenuated on the rear side of the article 1 .
Using the values obtainable from the graphs of FIGS. 10 and 11, graphs of the percentage attenuation as a function of the frequency were obtained (shown in FIGS. 12 and 13 ).
From the graphs of FIGS. 12 and 13, it is possible to deduce that in the 1-2 GHz frequency range, by means of the article according to the invention there is a percentage attenuation of the electromagnetic field of approximately 20%.
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An article for deflecting electromagntic fields consisting of a conductive meshed dry frbric with conductive filaments parallel to one another, bordered by a conductive fabric having a grid of filments arranged in criss-cross fashion. Connected to the fabric is an electric circuit designed to dissapate, by the Joule effect, the electromagnetic signal coming from the article.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to devices for optically connecting the ends of waveguides such as optical fibers, and more particularly to an article which splices a plurality of pairs of such optical fibers.
2. Description of the Prior Art
Splice devices for optical fibers are known in the art, but there is still a need for a quick and reliable method of splicing a plurality of fibers in a high density environment. Prior to the introduction of splice devices which join a plurality of optical fibers in a single splice body (discussed further below), this was accomplished by utilizing a plurality of single fiber (discrete) splice devices. This approach was very time consuming, however, and further resulted in a large volume of splice bodies which crowd junction boxes, or require specialized splice trays to keep the fibers organized.
Several systems have been devised to address the problem of multiple fiber splicing. One technique, mass fusion welding, requires that each fiber be placed in a groove of a rigid substrate having several such grooves. Best fit averaging is used to align the fiber pairs and an electric arc is created, melting the fiber tips and permanently fusing them together. The primary, and very significant, limitation of fusion splicing is the great expense of the fusion welders. Fusion welding also precludes later fiber removal or repositioning.
Another common multiple splicing technique requires the use of adhesives, again with a substrate or tray that has a plurality of grooves therein. For example, in U.S. Pat. No. 4,028,162, a plurality of fibers are first aligned on a plastic substrate having fiber aligning grooves, and then a cover plate is applied over the fibers and the substrate, the cover plate having means to chemically adhere to the fiber and substrate. Adhesives are also used in the optical fiber splice devices disclosed in U.S. Pat. No. 4,029,390 and Japanese Patent Application (Kokai) No. 58-158621. The use of adhesives is generally undesirable since it adds another step to the splicing process, and may introduce contaminants to the fiber interfaces. Splice devices using adhesives also require extensive polishing of the fiber end faces to achieve acceptable light transmission, and some adhesive splices further require the use of a vacuum unit to remove trapped air.
The '390 patent represents an improvement over earlier multiple splice devices in that it utilizes a foldable holder having a series of V-grooves on both sides of a central hinge region. The method of attaching the fibers to the holder, however, presents additional problems not present in earlier splices. First of all, since adhesive is used to affix the fibers to the holder before splicing, the cleaving of the fibers becomes a critical step since the cleave length must be exact to avoid any offset of the fiber end faces, which would be extremely detrimental to splice performance. Secondly, it is critical that the opposing V-grooves be exactly aligned, which is unlikely with the hinge depicted in the '390 patent; otherwise, there will be transverse fiber offset resulting in increased signal loss. Finally, the '390 holder would not maintain the opposing plates perfectly parallel, which is necessary in order to optimize transverse alignment of the fiber pairs, and also affects fiber deformation.
Another problem with several of the foregoing splicing devices is that they used rigid substrates to clamp the fibers. There are several disadvantages to the use of rigid substrates. First of all, it is generally more difficult to form grooves in a rigid material, such as by etching, grinding or erosion, which increases manufacturing cost. Rigid substrates must also be handled more carefully since they are brittle and thus easily damaged. Most importantly, the use of a rigid substrate having grooves therein results in poor alignment of the fiber pairs (as well as unnecessary fiber deformation), leading to higher insertion loss. These problems are compounded in stacked configurations such as those shown in U.S. Pat. Nos. 3,864,018, 4,046,454 and 4,865,413.
These difficulties may be avoided by the use of a substrate which is malleable, elastomeric or ductile. Unfortunately, however, the use of such materials has not been fully appreciated nor implemented. For example, U.S. Pat. No. 4,046,454 teaches that the rigid V-grooves may be lined with a ductile material. This complicates the manufacturing process, however, and adds significant cost. In U.S. Pat. No. 4,102,561, the splice device utilizes two alignment members formed of a resilient material which may deform against the fiber surfaces. That splice, however, requires the attachment of two subassemblies prior to insertion of the fibers into the alignment members, and further uses about a dozen clamps and bolts, making the device very difficult to use in the field (similar problems apply to the device illustrated in U.S. Pat. No. 4,045,121). The primary clamping action directly at the fiber interface also causes deformation of the fiber resulting in more signal loss than if there were a more gradual clamping toward the interface. This problem also applies to other splice designs, such as that depicted in European Patent Application No. 88303777.2, which further suffers from the non-uniform application of clamping forces to different fibers.
In light of the foregoing, it would be desirable and advantageous to devise a high performance splice device for multiple optical fibers which does not require fusion welding, or adhesives and polishing. The device should provide a uniform clamping force to each of the fibers, and provide gradual clamping to minimize undesirable deformations such as microbending at the clamp transition. The cleave length of the fibers should not be critical, and means should be provided to optimize fiber alignment, including the use of malleable clamping surfaces. Finally, the splice should be simple to use, especially for field installation.
SUMMARY OF THE INVENTION
The foregoing objectives are achieved in a device for splicing multiple optical fibers comprising a splice element, a body surrounding the splice element, and a wedge providing uniform, transverse clamping of the fibers in the splice element. The body may be comprised of a jacket portion and a cap portion which interlock to hold the splice element. The splice element is preferably formed of a malleable material, and is hinged to define two plates, one plate having a series of parallel V-grooves, and the plates being folded together prior to actuation by the wedge. Stop pads are interposed between the plates to insure gradual clamping when the wedge is forcibly urged against the plates or against a tongue which is interposed between the plates and the wedge. The splice element may further have an extension or porch, with a ramp to facilitate insertion of the fibers into the splice element.
A stacked splice element may be provided in the body having more than two plates, e.g., a three-plate stack accommodating two layers of fiber splices. Special guides positioned at each end of the plates may be used to direct some fibers upward to one splice layer and others downward to the other layer. End covers are provided to protect the splice element and exposed fibers, and to provide an environmental seal.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features and scope of the invention are set forth in the appended claims. The invention itself, however, will, best be understood by reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of the multiple optical splice device of the present invention;
FIG. 2 is an exploded perspective view of the splice device of the present invention;
FIG. 3 is a perspective view of the splice element used in the multiple fiber splice device of the present invention, in its unfolded state;
FIG. 4 is an enlarged sectional perspective of one end of the splice element of FIG. 3 showing the porch and ramp;
FIG. 5 is a sectional perspective view of the fully assembled splice device of the present invention;
FIG. 6 is a sectional elevation of an alternative end cover used with the splice device of the present invention, having a compartment therein for index matching gel; and
FIG. 7 is a perspective view of the stacked splice embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the figures, and in particular with reference to FIG. 1, there is depicted the multiple optical fiber splice device 10 of the present invention. Although the term "connector" may be applied to splice 10, that term is usually reserved for devices which are intended to provide easy connection and disconnection, as opposed to a splice which is usually considered permanent. Nevertheless, the term "splice" should not be construed in a limiting sense since splice 10 can indeed allow removal of the fibers, as explained further below.
With further reference to FIG. 2, splice 10 includes a generally rectangular body 12 which is essentially oomprised of a jacket 14 and a Cap 16. Splice 10 also includes a splice element 18 and longitudinal actuation means 20 for applying pressure to splice element 18. In the preferred embodiment, actuation means 20 comprises a wedge 22 having surfaces defining an acute angle, which is captured between jacket 14 and cap 16. A tongue 24, which is integrally molded with cap 16, is advantageously interposed between wedge 22 and splice element 18 as discussed further below. Jacket 14 has a longitudinal slot 26, rectangular in cross-section and extending through jacket 14, for receiving a splice element 18; slot 26 is slightly shorter than splice element 18, allowing both ends of element 18 to extend beyond the ends of slot 26. Jacket 14 also has an integrally molded male coupling element or projection 28 which fits within a cavity 30 formed in cap 16. Projection 28 has two transverse bumps 32 which snap into recesses 34 of cap 16, providing a snug fit between jacket 14 and cap 16.
Jacket 14 and cap 16 each have extensions 36 and 38, respectively, which receive end covers 40 and 42, respectively. Extensions 36 and 38 have recessed surfaces which support the fibers at the entrance to slot 26. End covers 40 and 42 impart protection to the spliced fibers and splice element 38 against environmental influences. End covers 40 and 42 are attached to extensions 36 and 38 of the jacket and cap, respectively, by any convenient means, such as arcuate jaws 44 which snap onto and rotatably grip trunnions 46. The side edges 48 of extensions 36 and 38 are rounded to allow end covers 40 and 42 to rotate on trunnions 46. End covers 40 and 42 also include hooks forming latches 50 which snap into notches 52 in extensions 36 and 38 and securely maintain the end covers in a tightly closed position.
Jacket 14 and cap 16 define many overlapping surfaces which impart additional environmental sealing and further inhibit separation of these two components of body 12 by, e.g., bending of body 12. For example, projection 2s has a lower tier 54 which slides under a canopy 56 formed on cap 16. Cap 16 also includes bosses 58 which fit into recesses (not visible in the Figures) in the corresponding face of jacket 14. Projection 28 and cap 16 further have inclined surfaces 60 and 62 which result in a greater contact surface area and make it more difficult to pop jacket 14 and cap 16 apart by bending them near their interface.
Turning now to FIGS. 3 and 4, splice element 18 is described in further detail. Splice element 18 may be formed from a sheet of deformable material, preferably a malleable metal such as aluminum, although polymeric materials may also be used. Material selection is described further below. Certain features are embossed, coined, stamped, molded or milled into element 18. First of all, a groove 70 is formed on the outside surface 72 of element 18. Groove 70 forms an area of reduced thickness to define a bend line or hinge, and separates element 18 into two legs Or plates 74 and 76 having essentially the same width. The hinge is preferably formed by additionally embossing a notch 78, opposite groove 70, on the inside surface 80 of element. This creates a "focus hinge" which provides more accurate registration of plates 74 and 76 when they are folded together, as explained further below. A slot 81 may also be punched out of element 18 to facilitate folding.
In one embodiment of the present invention, plate 76 has a series of V-shaped grooves 82 embossed on the inside surface 80 of element 18. V-grooVes 82 are generally parallel With groove 70. Those skilled in the art will appreciate that the V-grooves may instead be formed in plate 74, or in both plates, and further that the shape of the grooves is not limited to a "V" cross-section. Nevertheless, in the preferred embodiment only one of the plates has grooves therein, and these are V-shaped having an interior angle of about 60°. In this manner, when a fiber is placed in one of the grooves and clamped by surface 80 of plate 74, the points of contact between element 18 and the fiber generally form an equilateral triangle which minimizes transverse offset and thus reduces signal loss in the splice.
Plate 74 is further distinguished from plate 76 in that plate 74 has extensions or porches 84 which also have grooves 86 therein, although 9rooves 86 do not extend the full length of plate 74. Grooves 86 are also wider than V-grooves 82 since it is intended that the portion of the fibers lying on porches 84 will still have their buffer coating, but this coating is stripped from the fiber ends which are clamped between plate 74 and V-grooves 82 (i.e., the buffered portions of the fiber have a larger diameter than the exposed portions). Grooves 86 are further recessed in surface 80, and are adjacent to ramps 88 leading up to surface 80, as more clearly seen in FIG. 4. Ramps 88 eliminate microbending (which causes further signal loss) which would result if the buffered portion of the fiber and the exposed portion were to lie in the same plane. In other words, the transition from buffered fiber to exposed fiber occurs proximate ramps 88. Accordingly, the height of ramps 88 is approximately equal to the thickness of the buffer surrounding the fiber. Ramps 88 may be formed in porch areas 84 although they are preferably formed in plate 74 whereby they lie under plate 76 when the plates are folded together.
As an alternative to ramps 88, recesses (not shown) may be provided in extensions 36 and 38, under porches 84, to allow the porches to be bent slightly downward. Such a construction would be most advantageous if the alignment grooves on the porch of the element were continuous with the V-grooves in the center of the element, i.e., both sets of grooves were formed in only one of the plates forming the splice element. In this manner, after the fibers had been inserted and the element actuated, the porches could be bent down to relieve bending strain on the fiber caused by the transition in the effective diameter thereof due to the buffer coating.
The number of V-grooves 82 and 86 in splice element 18 is variable, depending upon the desired application. Grooves 86 should be aligned with V-grooves 82 when splice element 18 is folded, to insure proper positioning of the fibers during the clamping operation. Thus, while registration of plates 74 and 76 is not as critical as with some prior art splice devices (since there are no V-grooves on plate 74 which directly oppose V-grooves 82) it is still beneficial to use the aforementioned focus hinge in order to optimize th alignment of grooves 82 and 86.
In the stamping process which creates splice element 18, stop pads 90 are also advantageously formed on both plates 74 and 76 at the corners of the rectangle defined by the overlap of the plates. These pads are slightly raised with respect to the otherwise flat inside surface 8o of element 18. In this manner, When element 18 is folded as in FIG. 1, stop pads 90 provide a clearance space between plates 74 and 76, facilitating insertion of the fibers therebetween. Alternative methods of providing such a clearance space will become apparent to those skilled in the art. More importantly, however, stop pads 90 insure that, when element 18 is actuated and clamps the fibers, the maximum clamping force is exerted only along the central width of element 18, and the clamping force gradually decreases moving from the center toward the ends of element 18. This gradual clampinq transition has been found to significantly reduce signal loss resulting from the deformation of the fibers, i.e., prior art splice devices exhibited an abrupt clamping deformation which induced higher losses.
Assembly and operation of splice 10 are both straightforward and may best be understood with reference to FIG. 5. Splice element 18 is placed in slot 26 in a folded state; in this state, clearance is still provided by stop pads 90 to allow insertion of the fibers, so this may be considered an open state, as opposed to the closed, clamping state. An index matching gel is preferably deposited near the center of element 18. Wedge 22 is then placed adjacent tongue 24, and jacket 14 is snapped into cap i6, whereupon wedge 22 becomes disposed against another ramp 92 formed in the lower portion of jacket 14. The upper surface of wedge 22 is generally parallel with plates 74 and 76, while the lower surface of wedge 22 is parallel with ramp 92. Tongue 24 is further supported at its distal end by a shelf 94 formed in the lower portion of jacket 14, above ramp 92. End covers 40 and 42 may be attached to extensions 36 and 38 at any time in the assembly process (although they are not snapped into the closed position until after the fibers have been spliced). All of the foregoing steps take place in the factory, and splice 10 is provided to the user in the state shown in FIG. 1 (less the fiber ribbon).
When the user has located the fibers to be spliced, they should be stripped and cleaved according to well-known methods. In this regard, splice 10 may be used to splice the fiber ribbons 96a and 96b shown in FIG. 1, or may be used to splice a plurality of individual, discrete fibers. Such discrete fibers may be more conveniently handled by first arranging them side-by-side and applying a piece of tape or other means to effectively create a fiber ribbon. If fiber ribbon is being spliced, the outer coating which surrounds the individual buffered fibers should also be removed.
Once the fibers or ribbons have been inserted into body 12, splice 10 may be actuated by longitudinally sliding wedge 22 toward jacket 14. In this regard, the term "longitudinal" refers to movement parallel with the fibers and grooves 82. The sliding action may be accomplished by simply using a screwdriver or other tool to push wedge 22 forward. The screwdriver may be applied to the cutout 98 formed in wedge 22. As wedge 22 moves forward onto ramp 92, it causes tongue 24 to press against the outer surface of plate 74, clamping the fibers between plates 74 and 76. The width of tongue 24 is approximately equal to the groove sets in the plates As discussed above, the clamping forces gradually decreases towards the ends of splice element 18 due to stop pads 90. This effect may be enhanced by making the lengths of wedge 22 and tongue 24 shorter than the length of plates 74 and 76 so that the clamping force is applied primarily at the center of splice element 18, and not at its ends. In the preferred embodiment, the length of that portion of wedge 22 contacting tongue 24 is about one-half the length of plate 76. The use of tongue 24 also prevents undue deformation of plate 74 which might otherwise occur if wedge 22 were to contact splice element 18 directly Wedge 22 provides excellent mechanical advantages, including high transmission of forces, and the uniform application of force parallel to plates 74 and 76. Also, due to the coefficient of friction of the materials used for jacket 14, wedge 22 and tongue 24, actuation means 20 (i.e., wedge 22) may be self-locking, provided it has an angle of less than about 9°. The preferred angle is about 5°. If wedge 22 is provided with a detent or catch 99, which abuts a facing surface of cap 16, then self-locking capability is unnecessary. Simplicity in the use of splice 10 is evident from a summary of the above steps: stripping and cleaving the fibers, inserting them into body 12, and sliding wedge 22 forward. A double wedge (not shown) may be used in lieu of single wedge 22.
After the splice is completed, end covers 40 and 42 may be moved to the closed, latched position to provide environmental sealing and protect the exposed fibers. In this regard, legs 100 of the end covers, which rest on stage areas 102 of porches 84, help keep the fiber ribbon aligned with splice body 12, i.e., they oppose sideways bending of the ribbon proximate the entrance to slot 26. Legs 100 also provide additional sealing of slot 26 since they are positioned at the sides thereof. Although not designed for disconnection and reconnection, splice 10 may allow removal of fibers by simply opening end covers 40 and sliding wedge 22 backward. A space 103 may be provided between jacket 14 and wedge 22, in the actuated state, to allow insertion of a screwdriver or other tool for this purpose.
Several different materials may be used in the construction of splice 10. Splice element 18 may be constructed from a variety of malleable metals, such as soft aluminum. The preferred metal is an aluminum alloy conventionally known as "3003," having a temper of 0 and a hardness on the Brinnell scale (BHN) of between 23 and 32. Another acceptable alloy is referred to as "1100," and has a temper of 0, H14 or H15. Acceptable tensile strengths vary from 35 to 115 megapascals.
Other metals and alloys, or laminates thereof, may be used in the construction of splice element 18. Such metals include copper, tin, zinc, lead, indium, gold and alloys thereof. It may be desirable to provide a transparent splicing element to facilitate the splicing operation. In such a case, a clear polymeric material may be used. Suitable polymers include polyethylene terephthalate, polyethylene terephthalate glycol, acetate, polycarbonate, polyethersulfone, polyetheretherketone, polyetherimide, polyvinylidene fluoride, polysulfone, and copolyesters such as Vivak (a trademark of Sheffield Plastics, Inc., of Sheffield, Mass.).
As an alternative to providing a splice element constructed of a deformable material, it may instead be formed of a more rigid material provided that V-grooves 82 and/or surface 80 are lined with a deformable material. The primary requisite is to provide a material which is softer than the glass comprising the optical fiber and cladding, and which is malleable under the clamping pressures applied to the optical fiber. It is also desirable that the material be elastic at low stress levels to afford sufficient elasticity to maintain a continual compressive force on the optical fibers once plates 74 and 76 have been brought together. Furthermore, a coating may be applied to the malleable material to reduce skiving of the material as the fiber is inserted. For example, an obdurate coating in the range of 1 to 2 μm may be applied to surface so of splice element 18.
Splice body 12 may also be constructed of a variety of materials, basically any durable material and preferably one that is injeotion moldable, although die cast metals are acceptable. The material should not be too rigid as it is desirable to allow the inner walls forming slot 26 to flex slightly to store excess clamping forces from wedge 22 in order to insure constant clamping force on the fibers during temperature cycling. Injection moldable materials include liquid crystal polymer, such as that sold under the trademark VECTRA A130 by Hoechst Celanese Corp. of Summit, N.J.
The dimensions of splice 10 may vary widely according to the desired application. The following (approximate) dimensions, for the preferred embodiment, are exemplary only and should not be construed in a limiting sense. The oVerall length of splice 10 is 38 mm, its height 6.7 mm and its width 13 mm. The length of the main portion of jacket 14 is 14 mm, while projection 28 is about 7.1 mm long and 9.7 mm wide. Cap 14 is 7.6 mm long, and extensions 36 and 38 are each 8.3 mm long. Wedge 22 has an overall length of 14 mm, but the length of the portion contacting tongue 24 is 10 mm. The width of wedge 22 is 6.5 mm, while its maximum thickness is 1.5 mm and its minimum thickness is 0.76 mm.
With respect to splice element 18, several of the following approximate dimensions are based on the size of conventional multiple fiber ribbon cables. The length of plate 74 (including porches 84) is 28 mm, while the length of plate 76 is 20 mm. Both plates have a thickness of 530 μm, and stop pads 90 rise 18 μm above surface 80. V--grooves 82, preferably spaced 250 μm apart, are 130 μm deep and have a maximum width of 180 m. Grooves 86, which are approximately trapezoidal in the preferred embodiment, also have a maximum width of 80 μm, and a minimum width of 120 μm, and are 180 μm deep. Ramp 88 descends 250 μm, i.e., the upper surfaces of grooves 86 are 250 μm from surface 80.
Two alternative embodiments and design modifications are shown in FIGS. 6 and 7. FIG. 6 illustrates a modified end cover 42, which may be used on both jacket extension 36 and cap extension 38. End cover 42' is used to provide additional environmental sealing, by means of a compartment 104 defined by a wall 106 which is attached to the inner surface of cover 42' by a living hinge 108. As end cover 42, is closed, wall 106 contacts extension 38, Causing wall 106 to compress a sealant material, whioh may include index matching gel, residinq in compartment 106. Wall io6 has channels 110 therein which allow the sealant to escape from compartment 104, and flow in and around the entrance to slot 26. A web 112 is preferably integrally formed with wall 106, extending into compartment 104, which assures that sealant will be directed out of channels 110 when cover 42' is closed, and also provides resistance against such closure to prevent accidental leakage of the sealant.
FIG. 7 depicts a stacked splice device 10' which utilizes a splice element 18' having two layers of splices. Stacked splice element 18' may be formed of three separate elements, but it is preferably constructed of a single element having two integral hinges, folded into a Z-shape (accordion-fold). In this manner, the three sections of the sheet defined by the hinges result in three different plates 114, 115 and 116. It is not necessary that the two splice layers formed thereby be parallel, but this is preferred to simplify the wedge actuation. An alternative construction would provide a single sheet of material having two parallel hinges separated by a small distance, e.g., 50 μm, forming the upper and lower plates, with a third plate inserted therebetween. A plug 118 having two sets of orifices 124 is advantageously used to guide a first set of fibers, i.e., every other fiber, upwards to the top splice layer, and the remaining fibers downwards to the bottom splice layer. Guide plug 118 has grooves 120 formed in a porch area 122 thereof, similar to porch 84 of element 18; grooves 120 help align the fibers with orifices 124. Of course, the use of an accordion fold and guide plug could be expanded to splice elements having more than two splice layers.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. For example, a multiple fiber splice device may be constructed to allow separate termination of each fiber set by providing two actuation wedges, one at each end of splice body 12; this would allow the pretermination of one fiber set in the clamped state. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined in the appended claims.
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A device for splicing multiple optical fibers includes a splice element having means for holding the optical fibers, a splice body having a slot containing the splice element, and extensions on either end of the splice body for supporting a portion of the fibers. Each of the extensions has an end cover positionable in open and closed positions which provides protection to the fibers against environmental influences. The end covers may advantageously include collapsible compartments filled with a sealant material whereby, when the covers are moved to the closed positions, the sealant material is channeled towards the slot containing the splice element.
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FIELD OF THE INVENTION
[0001] The field of the invention relates to a tap dance barre practice and exercise device.
BACKGROUND OF THE INVENTION
[0002] Current methods used to teach advanced tap steps include grasping a ballet barre while demonstrating steps for one foot at a time. Another method, similar to that with the barre, is done while gripping the back of a folding chair. These methods limit range of motion which, in turn, hinders teaching. Additionally, students tend to hunch over to keep their balance, because it is extremely difficult to support oneself upright (not hunched) grasping a surface in front of the torso. Applicant's free-standing tap barre device provides support on two sides of the student's torso, and permits extended lateral leg movement in essentially all directions. Tap students can keep their ankles loose and properly execute specific tap sounds. The optional portable wooden board also enhances the students' ability to hear the steps they are practicing, further enhancing their tap skills. Additionally, the tap barre device allows the students to practice advanced tap steps slowly while maintaining the proper upright posture necessary to execute them correctly. This device aids intermediate tap dancers to advance, and it helps instructors demonstrate advanced movements to students, such as “wings” and “pullbacks,” two steps that require that both feet be airborne simultaneously.
[0003] The present invention is a device that has a horizontally fixed barre that may be curved for gripping attached to vertical support, which is in turn attached to a base which sits on a flat surface, such as a floor, and allows the device to be free-standing. It is critical that the barre be fixed horizontally for tap dance practice. If the barre rotated horizontally, it would cause the dancer to lose balance and possibly fall. Only a barre that is fixed horizontally can be used according to the present invention for practicing tap dance steps. Optionally the height of the barre can be raised or lowered vertically as needed. Further optionally, the vertical support can have a seat, and optionally the seat can pivot around the vertical support. The fixed barre substantially aligns vertically with the base, so that a user can support his torso by gripping or leaning on the barre, and the device remains balanced and free-standing. The device is designed to have the user's center of gravity located over the base, providing stability.
[0004] U.S. Pat. No. 4,637,604 (DuPont) discloses a device having a straddle seat chair and a stand with a post supporting an upwardly directed handle bar used to grip while sitting or standing and exercising the legs. The seat has a forward ledge, and the post is positioned in a base. FIG. 3 of DuPont discloses a seated user gripping the handle bar and practicing tap dancing. FIG. 4 of DuPont discloses a standing user with an extended arm gripping with one hand the handle bar while practicing tap dancing to the side of the device. The handle bar has an adjustable clamp 18 which allows the handle to be adjusted vertically and horizontally. U.S. Pat. No. 4,637,604 fails to disclose the present invention having a horizontally fixed barre which extends over the base, thereby providing a stable, free-standing device when used.
[0005] U.S. Pat. No. 6,726,608 discloses an exercise device having a base with a support rod extending from the base. A chair is placed atop the support rod and a swingable means is formed by a main arm, an auxiliary arm, a handle and at least one bearing. The device is used for exercise by having the user sit in the fixed seat, grasp the handle and swing the swingable means to exercise. This patent fails to disclose the present invention having a horizontally fixed barre which extends over the base, thereby providing a stable, free-standing device when used.
[0006] U.S. Pat. No. 7,559,881 discloses an exercise device having a base, a central shaft and an auxiliary shaft rotatably attached to the base with handles at the top of the shaft and leg rails at the bottom of the shaft. The device is used by placing a chair next to the device to seat the user, who places his hands on the handles and his feet on the leg rails and rotates the shafts by pushing and pulling the handles and leg rails. Neither this patent nor any permissible combination of the above patents teaches or suggests the present invention.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The present invention is a tap barre practice and exercise device that has a horizontally fixed barre that may be curved with at least one arm for gripping attached to a substantially straight vertical support, which is in turn attached to a base which sits on a flat surface and allows the device to be free-standing. Preferably, the barre has at least two arms. Optionally, the height of the barre can be raised or lowered vertically as needed. Further optionally, the vertical support can have a seat, and optionally the seat can pivot around the vertical support and be locked in one of two positions. The horizontally fixed barre substantially aligns vertically with the base, so that a user can support his torso by gripping or leaning on the barre and have his center of gravity located over the base, thereby providing a stable, free-standing device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
[0009] FIG. 1 is a side perspective elevated view of the tap barre practice and exercise device of the present invention;
[0010] FIG. 2 is a side perspective elevated view of the tap barre practice and exercise device of the present invention;
[0011] FIG. 3 is a side perspective elevated view of the barre portion of the practice and exercise device of the present invention;
[0012] FIG. 4 is a side perspective elevated view of the base portion of the practice and exercise device of the present invention; and
[0013] FIG. 5 is a side perspective elevated view of the tap barre practice and exercise device of the present invention with the optional tap board over the base.
DETAILED DESCRIPTION OF THE INVENTION
[0014] One embodiment of the present invention is disclosed in FIG. 1 . The tap barre device 1 is broadly disclosed in four components, the barre 10 , the vertical support 20 , the seat 30 and the base 40 . The barre 10 is approximately horizontal and may be curved tubing having at least one arm, and preferably two or more arms 12 . The barre 10 material can be a strong metal such as steel or aluminum, a composite or polymeric material. The material must have sufficient strength to bear the weight of the user without bending or breaking. Preferably, 1.25 inch o.d. steel pipe is used for construction. The curved shape provides optionally removable gripping surfaces 14 that can sustain the user's weight on two sides of the torso, rather than on one side of the torso. As shown in FIG. 3 , approximately mid-way along the curve of the barre 10 is a shaft 16 that extends downward and is designed to engage by insertion with the barre end 26 of the vertical support 20 . The shaft 16 has a bullet catch 18 that is used to engage one of the openings 22 in the vertical support 20 and adjust the vertical height of the barre 10 . The bullet catch 18 also works to fix the barre 10 horizontally, so that it does not rotate around the shaft 16 . Other forms of engagement with the openings 22 are also contemplated in this invention, including bolts, pins or locks. Preferably, there are about 5 openings 22 spaced to give an adjustment range of about 4 inches.
[0015] The vertical support 20 is essentially straight and vertical and extends from the barre end 26 to the base end 28 , and must be strong enough to bear the weight of the user without bending or breaking. Preferably, two inch o.d. steel pipe is used for the vertical support 20 , and is of sufficiently large diameter that the shaft 16 can be inserted into the vertical bar 20 . Near the barre end 26 of the vertical support 20 are spaced openings 22 that engage with the bullet catch 18 of the shaft 16 of the barre 10 . Near the base end 28 of the vertical support 20 is a bullet catch 29 which is used to engage an opening 46 in the upright 48 of the base 40 . When the bullet catch 29 is engaged with the opening 46 of the base 40 , the vertical support 20 is horizontally locked and cannot rotate. Optionally, the seat 30 is attached to the vertical support 20 by resting on a fixed collar 24 , which may be fixed by welding or other mechanical means, such as bolts or bullet catches, to support the removable seat 30 . As shown in FIG. 2 , the seat 30 is installed by sliding over and down the vertical support 20 and resting on the fixed collar 24 . Optionally, the seat 30 is able to rotate around the vertical support 20 and can be pivoted to the opposite side of the support 20 , away from the barre 10 , as is shown in FIG. 2 . Optionally, the seat 30 can be locked in one of two positions using a bullet catch, a bolt or other locking means (not shown). Optionally, the seat can be raised with the addition of removable collars (not shown) that are installed in a fashion similar to that of the seat 30 .
[0016] The base end 28 of the vertical support 20 is insertable into the upright 48 of the base 40 . As shown in FIG. 4 , the upright 48 is essentially vertical and is attached to the at least two legs 50 of the base 40 , which are essentially horizontal and rest on the floor. Optionally the legs 50 are curved and are aligned with the vertical support 20 to provide support essentially vertically under the barre 10 . The location of the legs 50 is critical to the stability of the tap barre device 1 , as it allows the weight of the user to be directly supported by the base 40 . The bullet catches 18 and 29 when engaged with the vertical support 20 and the base 40 allow the barre 10 to be substantially vertically aligned with the base 40 . Optionally, the base has reinforcing 42 along the curve of the legs 50 to further stabilize it and to prevent bending of the base as the barre 10 is used. Further optionally, there is at least one wheel 44 attached to the upright 48 which engages the floor when the vertical support 20 is tipped, allowing the device 1 to be moved by rolling rather than by lifting or dragging. Preferably, there are two or more wheels 44 .
[0017] As shown in FIG. 2 , the seat 30 is constructed of any suitable strong and durable material, such as metal, wood or plastic. Preferably, the seat is made of ½ inch plywood 38 , which is padded and covered with materials well-known in the art (not shown). The plywood seat rests on a sheet metal support 36 which is welded to a metal pipe collar 34 and reinforced with a sheet metal gusset 32 . The collar 34 is of sufficient diameter to fit over the vertical support 20 , and rest on the fixed collar 24 .
[0018] As shown in FIG. 5 , the optional tap board 52 rests on at least two pads 54 and is used as surface to practice tap dancing. The pads are used to raise the board 52 equal to or above the height of the legs 50 of the base 40 to stabilize the board 52 . Preferably there are four or more pads. The pads can be from about ½ inch to 1 inch high and made of rigid foam to absorb shock when used. Part of the process of learning tap dancing is listening to and making the appropriate tap sounds. A tap board 52 helps with that process. Any commercially available tap board can be used. Preferably, the tap board 52 is made of three layers of ¼ inch hardwood, with grain patterns perpendicular to each other for reinforcement, glued together and finished. Most preferably, 6 blocks are placed around the perimeter of the bottom of the tap board 52 .
[0019] The tap barre device 1 can be assembled as follows:
1. The base 40 is moved to the desired location. 2. The base end 28 of the vertical support 20 is inserted into the upright 48 of the base 40 . The bullet catch 29 on the vertical support 20 engages with the opening 46 of the base. 3. The collar 34 of the seat 30 is slid down the vertical support 20 and rests on the fixed collar 24 . 4. The shaft 16 of the barre 10 is inserted into the barre end 26 of the vertical support 20 . The bullet catch 18 of the barre 10 engages with one of the spaced openings 22 on the vertical support 20 , horizontally fixing the barre.
[0024] Optionally, the tap barre device 1 can be used without the chair 30 , and that step of the assembly can be eliminated. Optionally, the height of the chair can be raised by adding removable collars before installing the seat 30 . Optionally, the steps outlined above can be reversed or interchanged. There is no criticality in order of assembly, except that the chair must be installed before barre end 26 of the vertical support 20 is covered.
[0025] The tap barre device 1 can be disassembled by reversing the above steps and removing the parts. This allows the device to be stored or transported easily.
[0026] The assembled tap barre device 1 can easily be moved by tipping the vertical support 20 back onto the optional wheels 44 and rolling the device to the desired location.
[0027] To use the tap barre device 1 , a user can face the vertical support 20 and place his hands or forearms on the grips 14 , thereby supporting himself and moving his feet to practice steps. Alternatively, the user can have his back to the vertical support 20 , facing outward, place his hands or forearms on the grips 14 , and practice steps. During these two exercises, either the seat 30 is not installed, or it is rotated away from the barre side of the tap barre device 1 . Another method of use involves sitting on the seat 30 while resting the arms on the barre and practicing the steps while seated. The seat 30 is positioned on the barre side of the device when using this method. In any of the above methods may or may not use the tap board 52 .
[0028] While the invention has been described with respect to a certain specific embodiment, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.
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The present invention is a tap barre practice and exercise device that has a horizontally fixed barre with at two arms for gripping attached to a substantially straight vertical support, which is in turn attached to a base which sits on a flat surface and allows the device to be free-standing. The height of the barre can be raised or lowered vertically as needed, and the vertical support can have a seat, and optionally the seat can pivot around the vertical support and be locked in one of two positions. The barre substantially aligns vertically with the base, so that a user can support his torso by gripping or leaning on the barre and have his center of gravity located over the base, thereby providing a stable, free-standing device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to analogs of uracil nucleosides in the treatment of viral infections. More particularly, this invention relates to carbocyclic analogs of uracil nucleosides in which the pentose moiety of the nucleosides is replaced by a cyclopentane ring in the treatment of viral infections. This invention also relates to certain novel carbocyclic analogs of uracil nucleosides.
2. Description of the Prior Art
Uracil nucleosides and the phosphate derivatives (nucleotides) of these nucleosides are obligatory components of the biosynthesis of nucleic acids, of certain interconversions of pyrimidine nucleosides and nucleotides, and of other essential biochemical events. Structural analogs of uracil nucleosides may interfere with enzymatic processes that require uracil nucleosides and nucleotides. Because of the essential involvement of uracil nucleosides and nucleotides in vital biochemical processes, interference with their functions may be manifested as important biological activity. The best known examples of clinically useful, antiviral nucleosides are 5-iodo-2'-deoxyuridine (IdUrd), a uracil nucleoside, and 9-β-D-arabinofuranosyladenine (Ara-A), a purine nucleoside. The antiviral activities, the clinical usefulness, and the disadvantages of IdUrd have been described in review articles such as "Recent Advances in Chemotherapy of Viral Diseases" by W. H. Prusoff in Pharmacological Reviews, volume 19, pages 209-250, 1967; "Purines and Pyrimidines" by F. M. Schabel, Jr., and J. A. Montgomery in Chemotherapy of Virus Diseases, The International Encyclopedia of Pharmacology and Therapeutics, volume 1, edited by D. J. Bauer, Pergamon Press, Oxford and New York, 1972; and "Antiviral Agents as Adjuncts in Cancer Chemotherapy" by W. M. Shannon and F. M. Schabel, Jr., in Pharmacology and Therapeutics, volume 11, pages 263-390, Pergamon Press, Oxford, Great Britain, 1980. Reviews of the antiviral activity of Ara-A include the latter review of Shannon and Schabel and "The Antiviral Activity of 9-β-D-arabinofuranosyladenine (Ara-A)" by F. M. Schabel, Jr., in Chemotherapy, volume 13, pages 321-338, 1968.
The term "carbocyclic analog of a nucleoside" designates a compound that has the same chemical structure as the nucleoside except that the oxygen atom of the furanose moiety of the nucleoside is replaced by a methylene group in the carbocyclic analog; or, differently expressed, in the carbocyclic analog a cyclopentane ring replaces the tetrahydrofuran ring of the analogous nucleoside. Such nucleoside analogs were designated carbocyclic analogs of nucleosides by Shealy and Clayton, Journal of the American Chemical Society, volume 88, pages 3885-3887, 1966. The natural nucleosides and many of their true nucleoside analogs are subject to the action of enzymes (phosphorylases and hydrolases) that cleave the nucleosides to the pentose and pyrimidine (or purine) moieties. The biological effects of such true nucleoside analogs may be lessened by the action of these degradative enzymes. In contrast, carbocyclic analogs of nucleosides do not possess the glycosidic bond present in the true nucleosides and, therefore, are not subject to the action of these degradative enzymes. They may also be more selective in their biological actions.
Carbocyclic analogs of uracil nucleosides in which X of Formula I, below, is hydrogen or methyl have been previously described by Shealy and O'Dell, Journal of Heterocyclic Chemistry, volume 13, pages 1015-1020, 1041-1047 and 1353-1354, 1976; and by Shealy, O'Dell and Thorpe, Journal of Heterocyclic Chemistry, volume 18, pages 383-389, 1981. Certain carbocyclic analogs of cytosine nucleosides have also been synthesized and described and their antiviral activity revealed by Shealy and O'Dell in U.S. Pat. No. 4,177,238, Dec. 4, 1979; U.S. Pat. No. 4,232,154, Nov. 4, 1980; and Journal of Heterocyclic Chemistry, volume 17, pages 353-358, 1980. The two U.S. patents disclose that analogs in which X of Formula I, below, is hydrogen, lower alkyl or halogen may be used as intermediates in the preparation of the cytosine nucleoside analogs. These patents also disclose that the hydroxyl groups on such compounds may be reacted with an acylating agent. Murdock et al in Journal of the American Chemical Society, volume 84, pages 3758-3764 (1962) claimed the formula of the carbocyclic analog of thymidine, i.e., the formula: ##STR2## However, Shealy, O'Dell, and Thorpe, Journal of Heterocyclic Chemistry, Volume 18, pages 383-389, 1981, have shown that the compound claimed by Murdock is not the carbocylic analog of thymidine. None of these references disclose that the carbocyclic analogs of uracil nucleosides mentioned therein exhibit antiviral activity.
SUMMARY OF THE INVENTION
It has now been found that certain carbocyclic analogs of uracil nucleosides exhibit potent and advantageous activity against herpes viruses and other DNA viruses. Thus, in accordance with this invention, there is administered to a host animal, including man, afflicted with a viral infection a therapeutically effective amount of a carbocyclic analog of a nucleoside represented by Formula I ##STR3## wherein X of chlorine, bromine, iodine, a lower alkyl group or an amino group of the formula --NHR 2 wherein R 2 is a lower alkyl group; and R and R 1 can be the same or different members selected from the group consisting of hydrogen, an alkanoyl group or an aroyl group. By "lower alkyl" is meant an alkyl group containing from one to six carbon atoms.
Compounds of Formula I are analogs of 5-substituted-2'-deoxyuridines in which the pentose moiety of the true (or conventional) nucleosides is replaced by an appropriately substituted cyclopentyl group; i.e., the tetrahydrofuran ring of the conventional nucleoside structure is replaced by a cyclopentane ring.
DETAILED DESCRIPTION OF THE INVENTION
Syntheses of the analogs of 5-substituted-2'-deoxyuridines may be carried out by beginning with the corresponding carbocyclic analogs of uracil nucleosides; i.e., compounds of Formula I wherein X is hydrogen. The synthesis of these precursor carbocyclic analogs was described by Shealy and O'Dell, Journal of Heterocyclic Chemistry, volume 13, pages 1015-1020, 1976. Alternatively, certain carbocyclic analogs of 5-substituted-2'-deoxyuridines may be synthesized from acyclic precursors according to the route described in the Journal of Heterocyclic Chemistry, volume 13, pages 1015-1020, 1976, except that the acyclic precursor bears a group positioned so as to become the desired 5-substituted-2'-deoxyuridine analog. For example, treatment of the carbocyclic analog of Formula I, wherein X, R and R 1 are each hydrogen, with bromine after the hydroxy groups have been acylated produces carbocyclic analogs of acylated 5-bromo-2'-deoxyuridines (Formula I, X=Br and R and R 1 are acyl groups). Hydrolysis of the acyl derivatives then produces the corresponding unacylated compound in which R and R 1 are hydrogen. The carbocyclic analogs (Formula I, X=I) of 5-iodo-2'-deoxyuridines may be synthesized by treating the precursor analogs (Formula I, X=H) with iodine in a mixture of chloroform and nitric acid. The compounds that are carbocyclic analogs of 5-(substituted-amino)-2'-deoxyuridines may be obtained by treating the appropriate 5-halouracil analogs (Formula I, X=Br, I, or Cl) with the appropriate amine.
The carbocyclic analogs of 5-substituted-2'-deoxyuridines of Formula I have pronounced antiviral activity and may be used in the treatment of various human and animal diseases caused by DNA viruses, such as herpes simplex viruses. For such uses, certain of these compounds offer distinct advantages over known and currently used antiviral nucleosides. Thus, certain of the carbocyclic analogs of 5-substituted-2'-deoxyuridine nucleosides are more active in inhibiting the replication of herpes simplex virus, type 1, than is, the clinically active drug 9-β-D-arabinofuranosyladenine (Ara-A). Furthermore, the carbocyclic analog of 5-iodo-2'-deoxyuridine (IdUrd) is active against experimental herpes simplex virus infection of the brain (encephalitis) as demonstrated by treatment of mice innoculated intracerebrally with herpes simplex virus, whereas IdUrd itself does not exhibit this type of antiviral activity (F. M. Schabel, Jr., Chemotherapy, volume 13, pages 321-328, 1968). The compounds of Formula I are administered in any physiologically acceptable method, e.g., topically or parenterally, in a therapeutically effective amount. Determination of optimum dosages is within the skill of the art.
The following examples illustrate the preparation of the compounds of Formula I. In these examples, the system of designating the orientation of substituents on the cyclopentane ring as α or β is that used by Chemical Abstracts, beginning with volume 76, in the Chemical Substance Index.
EXAMPLE 1
(±)-5-Bromo-1-[(1α,3β,4α)-3-hydroxy-4-(hydroxymethyl)cyclopentyl]-2,4(1H,3H)-pyrimidinedione Diacetate (Formula I, X=Br, R=R 1 =CH 3 CO--)
A mixture of acetic anhydride (11 ml) and (±)-1-[(1α,3β,4α)-3-hydroxy-4-(hydroxymethyl)cyclopentyl]-2,4(1H,3H)-pyrimidinedione (the carbocyclic analog of 2'-deoxyuridine) (1.00 gram) was boiled under reflux until the mixture became a homogeneous solution. The solution was cooled to room temperature and was stirred and maintained at 25° C. while a solution of bromine (826 mg.) in 1.1 ml. of acetic acid was added dropwise. The resulting solution was stirred at room temperature for 3 hours and then stored overnight at low temperature (about 5° C.) after additional reagent (206 mg. of bromine in 0.3 ml. of acetic acid) had been added. Volatile components were evaporated from the reaction solution under reduced pressure, and the crystalline residue was triturated with an ethanol-ether (1:1) mixture. The white solid was collected by filtration and dried under reduced pressure at 78° C.: weight, 1.605 grams (93% yield). Ultraviolet absorption data showed that this material was comparable to an analytically pure specimen. This compound may be purified, if desired, by recrystallizing it from ethanol: recovery, 84%; m.p. 164°-167° C.; ultraviolet absorption maxima in nanometers at 284 (ε10,400) and 212 (ε10,000) at pH 1, 282 (ε9900) and 211 (ε9600) at pH 7, and 280 (ε7100) at pH 13; mass spectral peaks (M=molecular ion) at m/e 388 (M), 328 (M--CH 3 COOH), 285 (M--CH 3 CO--CH 3 COOH), 268 (M--2CH 3 COOH), 190 (5-bromouracilyl group+H); infrared spectrum (KBr disc, bands in the 1800-1400 cm -1 region): 1740, 1720, 1700, 1680, 1620, 1500 (weak), 1460 (shoulder), 1450, 1430, 1380, 1360, 1320.
Analysis. Calcd. for C 14 H 17 BrN 2 O 6 : C, 43.20; H, 4.40; N, 7.20. Found: C, 43.06; H, 4.50; N, 7.24.
EXAMPLE 2
(±)-5-Bromo-1-[(1α,3β,4α)-3-hydroxy-4-(hydroxymethyl)cyclopentyl]-2,4(1H,3H)-pyrimidinedione (Formula I, X=Br, R=R 1 =H), The Carbocyclic Analog of 5-Bromo-2'-deoxyuridine
A solution of the diacetate (540 mg.) of Example 1 in 25 ml. of ammonia in methanol (10% ammonia) was stirred at room temperature for 72 hours and then concentrated to dryness under reduced pressure. The residue was dissolved in hot water (10 ml.), the solution was treated with activated carbon and filtered, and the filtrate (plus washings) was concentrated to about one-half of the original volume. After the concentrated solution had been stored at low temperature (about 5° C.), the white crystalline product was collected by filtration, washed sparingly with water, and dried in vacuo at 78° C.: yield 251 mg. (52%); m.p. 188°-193° C. After the filtrate had been concentrated and refrigerated, an additional quantity (60 mg., total yield=73.7%) of the desired carbocyclic analog was obtained in the same manner: m.p. 189°-194° C.; ultraviolet absorption maxima in nanometers at 284 (ε10,000) and 212 (ε9400) at pH 1, 284 (ε10,000) and 212 (ε9600) at pH 7, and 280 (ε7400) at pH 13; mass spectral peaks (M=molecular ion) at m/e 304 (M), 286 (M--H 2 O), 274, 255 (M--H 2 O--CH 2 OH), 247, 217 (5-bromouracilyl group+C 2 H 4 ), 191 (5-bromouracilyl group+2H), 190 (5-bromouracilyl group+H); infrared spectrum (KBr disc, bands in the 1800-1300 cm -1 region): 1695, 1685, 1645, 1630 (shoulder), 1610, 1505 (weak), 1460, 1445, 1425, 1415 (shoulder), 1375, 1345, 1310.
Analysis. Calcd. for C 10 H 13 BrN 2 O 4 : C, 39.49; H, 4.29; N, 9.21. Found: C, 39.19; H, 4.29; N, 9.16.
EXAMPLE 3
(±)-1-[(1α,3β,4α)-3-Hydroxy-4-(hydroxymethyl)cyclopentyl]-5-iodo-2,4(1H,3H)-pyrimidinedione (Formula I, X=I, R=R 1 =H)
A solution of iodine (2.49 g.) in chloroform (13 ml.) was added to a solution of 2.175 g. of the carbocyclic analog (Formula I, X=R=R 1 =H) of 2'-deoxyuridine in 1 N nitric acid (22 ml.), and the resulting mixture was heated under reflux for 2 hours and then stored overnight in a refrigerator (at about 5° C.). The chloroform layer was separated, and the water layer, which now contained a white solid, was again refrigerated. The white crystalline solid was collected by filtration, washed with cold water, and dried in vacuo at room temperature. The crude product (2.914 g.) was dissolved in hot water (75 ml.); the solution was filtered and then refrigerated; and the recrystallized product was collected by filtration, washed with cold water, and dried in vacuo at 78° C.: yield, 2.58 g. (76%); m.p. 197°-199° C.; ultraviolet absorption maxima (in nanometers) at 292 (ε8800) and 217 (ε10,900) at pH 1, 293 (ε8700) and 217 (ε11,000) at pH 7, 283 (ε6400) at pH 13; mass spectral peaks (M=molecular ion) at m/e 352 (M), 334 (M--H 2 O), 322, 303 (M--H 2 O--CH 2 OH), 295, 293, 265 (5-iodouracilyl group+C 2 H 4 ), 260, 239 (5-iodouracilyl group+2H), 238 (5-iodouracilyl group+H), 225 (M--I); infrared spectrum (KBr disc, bands in the 1800-1300 cm -1 region): 1690, 1640, 1600, 1505, 1460, 1420, 1400 (shoulder), 1345, 1305; proton nuclear magnetic resonance spectrum (100.1 MHz, dimethylsulfoxide-D 6 solution, δ in parts per million downfield from tetramethylsilane as internal standard): 1.2-1.7 and 1.7-2.3 (overlapping multiplets), 3.3-3.7 (multiplet), 4.0 (approximate center of multiplet), 4.5-4.7, 4.6-4.8, 4.6-5.2 (overlapping multiplets), 8.13 (singlet), 11.58 (broad singlet).
Analysis. Calcd. for C 10 H 13 IN 2 O 4 : C, 34.11, H, 3.72; N, 7.96. Found: C, 33.93; H, 3.77; N, 8.25.
EXAMPLE 4
(±)-1-[(1α,3β,4α)-3-Hydroxy-4-(hydroxymethyl)cyclopentyl]-5-iodo-2,4(1H,3H)-pyrimidinedione Diacetate (Formula I, X=I, R=R 1 =CH 3 CO--)
A solution prepared from 450 mg. of the carbocyclic analog of 5-iodo-2'-deoxyuridine (Example 3), pyridine (20 ml.), and acetic anhydride (1 ml.) was stirred at room temperature for 3 days and then concentrated to a low volume. Cold water was added dropwise to the concentrated solution, and the resulting mixture, containing a gummy precipitate, was placed in a refrigerator to allow crystallization to occur. The crystalline precipitate was collected by filtration, washed well with cold water, and dried in vacuo at 78° C.: yield, 550 mg. (99%); m.p. 183°-186° C.; ultraviolet absorption maxima in nanometers at 293 (ε8100) and 218 (ε10,200) at pH 1, 292 (ε8000) and 217 (ε10,200) at pH 7, and 284 (ε5800) at pH 13; mass spectral peaks (M=molecular ion) at m/e 436 (M), 376 (M--CH 3 COOH), 316 (M-- 2CH 3 COOH), 303 (M--CH 3 COOH--CH 2 OCOCH 3 ), 265 (5-iodouracilyl group+C 2 H 4 ), 239 (5-iodouracilyl group+2H), 238 (5-iodouracilyl group+H); infrared spectrum (KBr disc, bands in the 1800-1300 cm -1 region): 1725, 1690, 1665, 1610, 1590, 1515 (weak), 1445, 1435, 1420, 1375, 1355, 1345, 1320, 1305.
Analysis. Calcd. for C 14 H 17 IN 2 O 6 : C, 38.55; H, 3.93; N, 6.42. Found: C, 38.64; H, 4.05; N, 6.43.
EXAMPLE 5
(±)-1-[(1α,3β,4α)-3-Hydroxy-4-(hydroxymethyl)cyclopentyl]-5-(methylamino)-2,4(1H,3H)-pyrimidinedione (Formula I, X=--NHCH 3 , R=R 1 =H)
A solution of the carbocyclic analog of 5-bromo-2'-deoxyuridine (Example 2, 175 mg.) in a 50% solution (30 ml.) of methylamine in methanol was heated at 90°-100° C. for 20 hours in a sealed stainless-steel bomb. The reaction solution was removed from the bomb, concentrated with a current of nitrogen to remove ammonia, and then concentrated in vacuo to a foam. A water (25 ml.) solution of the residue was chromatographed on a column of a cation resin (Amberlite CG-120, H + form). The resin column was washed thoroughly with water, and the 5-(methylamino)-2'-deoxyuridine analog was eluted from the column with 1 N aqueous ammonia. The basic eluate was concentrated to dryness in vacuo, ethanol (3 ml.) was added to the residue, the cloudy solution was filtered, and the clear filtrate was diluted carefully with ether (10 ml.). A white solid was collected by filtration, washed with ether, and dried in vacuo at 78° C.; weight, 37 mg. The filtrate was diluted with ether, and a second crop of white solid was then obtained in the same way; weight, 73 mg. (total yield as a hemihydrate=65.8 %). The two crops of product were combined in hot ethanol, the solution was filtered, and the hot filtrate was diluted with ether. The white precipitate was collected by filtration, washed with ether, and dried in vacuo at 78° C.: recovery, 73%, ultraviolet absorption maxima in nanometers at 270 (ε9400) at pH 1, 303 (ε6400) and 236 (ε6800) at pH 7, and 294 (ε5800) and 230-240 (slight shoulder) at pH 13; mass spectral peaks (M=molecular ion) at m/e 256 (M+1), 255 (M), 237 (M--H 2 O), 224 (M--CH 2 OH), 206 (M--H 2 O--CH 2 OH), 167, 141 (5-(methylamino)uracilyl group+H); infrared spectrum (KBr disc, bands in the 1800-1300 cm -1 region): 1700, 1660, 1635, 1595, 1585 (shoulder), 1510, 1500, 1475, 1465, 1455, 1440, 1425, 1395, 1370, 1320.
Analysis. Calcd. for C 11 H 17 N 3 O 4 .0.5H 2 O: C, 49.99; H, 6.87; N, 15.90. Found: C, 50.02; H, 6.71; N, 15.70.
EXAMPLE 6
(±)-5-(Butylamino)-1-[(1α,3β,4α)-3-hydroxy-4-(hydroxymethyl)cyclopentyl]-2,4(1H,3H)-pyrimidinedione (Formula I, X=--NHC 4 H 9 , R=R 1 =H)
A solution of the carbocyclic analog (Example 1, 400 mg.) of 5-bromo-2'-deoxyuridine diacetate in butylamine (25 ml.) was heated under reflux for 20 hours and then concentrated in vacuo to a gummy residue. Water (20 ml.) was added to the residue, and the aqueous mixture was extracted three times with 20-ml. portions of ether and then concentrated in vacuo to a colorless syrup (weight, 280 mg.). A water (50 ml.) solution of the residual syrup was chromatographed on a column of a cation resin as described in Example 5, and the basic eluate was concentrated in vacuo to a syrup that was dissolved in ethanol. The ethanol solution was filtered and concentrated to a colorless syrup; weight, 248 mg. (81% yield calculated as the free base form of the compound named in the title). The free base was converted to a sulfate salt as follows: 1 N sulfuric acid (1 ml.) was added to an ethanol (20 ml.) solution of the free base, the solution was concentrated to a low volume, the addition of ethanol and the concentration of the resulting solution were repeated several times to remove water, and ether was then added to the concentrated solution. A white solid, collected in two crops, was separated by filtration, washed with ether, and dried in vacuo at 78° C.: yield, 170 mg. (44% calculated as a sulfate, 1.25 hydrate); mass spectral peaks (M=molecular ion) at m/e 297 (M), 279 (M--H 2 O), 254 (M--C 3 H 7 ), 236 (M--C 3 H 7 --H 2 O), 183 (5-butylamino)uracilyl group+H); infrared spectrum (KBr disc, bands in the 1800-1000 cm -1 region): broad bands centered at 1690, 1585, 1495, 1465, 1440, 1395, 1380 (shoulder), 1310 (shoulder), 1280, 1210, 1165, 1115, 1040.
Analysis. Calcd. for C 14 H 23 N 3 O 4 .0.5H 2 SO 4 .1.25H 2 O: C, 45.58; H, 6.97; N, 11.40. Found: C, 45.55; H, 6.82; N, 11.85.
EXAMPLE 7
Antiviral Activity of Carbocyclic Analogs of 5-Substituted-Uracil Nucleosides
Carbocyclic analogs of 5-substituted-2'-deoxyuridines were tested for antiviral activity against viruses that replicate in mammalian cells growing in cell culture. The results of these tests against herpes simplex virus, Type 1, growing in rabbit kidney cells are summarized in Table 1. The Virus Rating (VR) is a weighted measurement of antiviral activity determined by the method of Ehrlich et al, Annals of the New York Academy of Science, volume 130, pages 5-16, 1965. In tests carried out by this method, a VR of 0.5-0.9 indicates marginal to moderate antiviral activity and a VR equal to or greater than 1 indicates definite antiviral activity. The higher the value of VR, the greater is the antiviral activity. The MIC 50 (minimum inhibitory concentration, 50%) is the concentration of a test compound required for 50% inhibition of virus-induced cytopathogenic effect. The tests summarized in Table 1 show that carbocyclic analogs of 5-substituted-2'-deoxyuridines possess definite antiviral activity. Especially significant is the very high activity exhibited by the carbocyclic analog (Example 2) of 5-bromo-2'-deoxyuridine, the carbocyclic analog (Example 3) of 5-iodo-2'-deoxyuridine, the carbocyclic analog (Example 5) of 5-(methylamino)-2'-deoxy-uridine and the carbocyclic analog of thymidine. Furthermore, the compounds of Examples 2, 3, and 5 and the carbocyclic analog of thymidine showed high activity against Type 2 herpes simplex virus, values of VR being 1.5, 3.4, 1.2, and 3.2, respectively.
The advantage conferred by the presence of a substituent at position 5 of carbocyclic analogs of 2'-deoxyuridines is demonstrated by the fact that the parent compound, the carbocyclic analog of 2'-deoxyuridine (Formula I, X=H, R=R 1 =H), is not active against herpes simplex virus (Table 1). However, not all carbocyclic analogs of 5-substituted-2'-deoxyuridines exhibit activity against herpes simplex virus. For example, the representative of Formula I wherein X is a primary amino group (NH 2 ) and R and R 1 are hydrogen was devoid of significant activity (VR=0.1) in the same type of test in which the compounds of Examples 5 and 6 (X=--NHR 2 ) are active (Table 1). Furthermore, in contrast to the high activity (Table 1) of the 5-halogen derivatives of Example 2 (Formula I, X=Br, R=R 1 =H) and Example 3 (Formula I, X=I, R=R 1 =H), another 5-halogen derivative, the carbocyclic analog of 5-fluoro- 2'-deoxyuridine (Formula I, X=F, R=R 1 =H), was not active (VR=0) in the same type of test against herpes simplex virus (Table 1).
Carbocyclic analogs of 5-substituted-2'-deoxyuridines may inhibit the replication of other DNA viruses. Thus, the carbocyclic analog (Example 3) of 5-iodo-2'-deoxyuridine is active against varicella-zoster virus replicating in human foreskin fibroblasts (Table 2). In a virus yield-reduction experiment, Example 3 produced a reduction in the titer of virus progeny ≧4.0 log 10 , and there were no observable virus-induced cytopathogenic effects at 10 days postinfection. The IdUrd analog (Example 3) was also active against murine leukemia virus, an RNA tumor virus. Replication of this virus in mouse embryo cells was completely inhibited at a drug concentration of 32 μg/ml.
TABLE 1______________________________________Antiviral Activity of Carbocyclic Analogs of5-Substituted-2'-deoxyuridines Herpes Simplex Virus, Type 1Compound Virus Rating (VR) MIC.sub.50 (mcg/ml)______________________________________Example 1 1.3 92Example 2 6.2 0.3Example 3 7.1 0.3Example 4 2.4 10Example 5 3.9 15Example 6 2.0 290Carbocyclic analog 5.4 0.8of thymidineFormula I, X = F, 0R = R.sup.1 = HFormula I, X = H, 0R = R.sup.1 = H______________________________________
TABLE 2______________________________________Inhibition of Varicella-Zoster Virus ReplicationIn Human Foreskin Fibroblasts by Example 3DrugCon- Virus-Induced Virus Log.sub.10centra- Cytopathogenic Yield Reductiontion, Effects at 10 Days Log.sub.10 in VirusμM Postinfection, % CCID.sub.50 /ml Titer______________________________________Virus 0 90 ≧4.5 0ControlsExample 3 320 0 ≦0.5 ≧4.0 100 0 ≦0.5 ≧4.0 32 0 ≦0.5 ≧4.0______________________________________ Virus titers are expressed in terms of log.sub.10 CCID.sub.50 (cell culture infectious dose, 50%) units per ml., and the reduction in virus yield after drug treatment is expressed as a logarithm.
EXAMPLE 8
Comparisons of Antiviral Activity
The results of antiviral tests, performed as described in Example 7, of 5-iodo-2'-deoxyuridine (IdUrd), the carbocyclic analog (Example 3) of 5-iodo-2'-deoxyuridine, 9-β-D-arabinofuranosyladenine (Ara-A), the carbocyclic analog (Example 2) of 5-bromo-2'-deoxyuridine, the carbocyclic analog (Example 5) of 5-(methylamino)-2'-deoxyuridine and the carbocyclic analog of thymidine are summarized in Table 3. These results show that these carbocyclic analogs are more active than is Ara-A and that the carbocyclic analog of IdUrd is comparable in activity in these tests to IdUrd.
TABLE 3______________________________________Comparisons of Antiviral Activity Herpes Simplex Virus, Type 1 Virus MIC.sub.50Compound Rating (VR) (mcg/ml)______________________________________5-Iodo-2'-deoxyuridine 6.9, 7.9 0.3Carbocyclic analog of 5-iodo- 7.9, 7.4 0.1, 0.42'-deoxyuridine (Example 3)9-β-D-Arabinofuranosyladenine 2.7 (average) 9.8(Ara-A)Carbocyclic analog of 5'-bromo- 6.2 0.32'-deoxyuridine (Example 2)Carbocyclic analog of 5- 4.2 10.0(methylamino)-2'-deoxy-uridine (Example 5)Carbocyclic analog of thymidine 5.4 0.8______________________________________
EXAMPLE 9
Activity of the Carbocyclic Analog of 5-Iodo-2'-deoxyuridine In Vivo
Mice were inoculated intracerebrally with ten times the LD 50 of herpes simplex virus. (The LD 50 is the amount of virus that would be lethal to 50% of the inoculated animals.) Some of these virus-infected mice were treated for seven days with the carbocyclic analog (Example 3) of IdUrd, and some of these virus-infected mice were not treated and served as a control group. The results of this experiment are summarized in Table 4. These results show that this compound is active against herpes encephalitis in experimental animals; in contrast, it has been shown that IdUrd itself is not active against herpes encephalitis in mice (F. M. Schabel, Jr., Chemotherapy, volume 13, pages 321-328, 1968).
TABLE 4______________________________________Activity of the Carbocyclic Analog of 5-Iodo-2'-deoxyuridineAgainst Intracerebral Herpes Simplex Virus in Mice % of % of Infected Mice Infected MiceDose that lived less that lived 10 Median Survivalmg./kg. than six days days or longer Time in Days______________________________________400 0 50 8.8300 10 40 9.20 (control 50 10 6.1 group)______________________________________
Although the invention has been described in considerable detail with specific reference to certain advantageous embodiments thereof, variations and modifications can be made without departing from the scope of the invention as described in the specification and defined in the appended claims.
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There is provided a method for the treatment of viral infections by treating a host animal with a pharmaceutically effective amount of a carbocyclic analog of a nucleoside represented by Formula I: ##STR1## wherein X is chlorine, bromine, iodine, a lower alkyl group or an amino group of the formula --NHR 2 wherein R 2 is a lower alkyl group; and R and R' can be the same or different members selected from the group consisting of hydrogen, an alkanoyl group or an aroyl group.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to sutures for use in surgery.
2. Description of the Prior Art
Sutures of silk have long been known and used for various surgical applications. Conventional sutures are of various types and include those prepared by twisting, braids formed by plaiting, and braids having a core. The known suture is made of silk only and therefore has the drawback of being low in stiffness and having very poor ability to restore itself when deformed. For example, the suture wound on a reel remains helically curled when unwound therefrom and is difficult to straighten to a corrected form. The same difficulty is also encountered with the suture wound around a paper core.
If the suture used is as curled the suture will coil around the arm or hand of the surgeon or hang down in a helical form due to its excessive flexibility and causes great frustration to the surgeon.
To overcome this problem, we have proposed a suture comprising a core of synthetic fiber filament yarn and a braid or the like of silk strands covering the core (Japanese Utility Model Application No. 41670/1987). The proposed suture is given suitable flexibility due to the appropriate rigidity of the filament yarn as afforded by doubled polyester filament strands in combination with the flexibility of the silk strands covering the yarn, whereby the suture is made amenable to the correction of its deformation such as the curl due to winding so as to be easily handled. Furthermore, the suture has a higher breaking strength than those consisting solely of silk strands owing to the presence of the core of synthetic fiber filament yarn. However, the suture still remains to be improved since there is a demand for sutures having higher strength.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide a surgical suture meeting this demand, and more particularly a suture which has a suitable flexibility and high amenability to the correction of deformation such as the curl due to winding on a reel and is easy to handle and which further has an exceedingly high breaking strength.
To fulfill the above object, the present invention provides a surgical suture characterized in that the suture comprises a core of at least one synthetic fiber filament yarn, and a covering layer formed of a plurality of silk strands and sheathing the core, the core and the covering layer having substantially the same elongation at break.
The core can be formed of a plurality of synthetic fiber filament yarns extending in parallel to one another and each having substantially the same elongation at break as the covering layer.
Furthermore, the core can be formed of single-twisted or plied filament yarns of synthetic fiber and made to have substantially the same elongation at break as the covering layer.
Furthermore, the core can be formed by plaiting a plurality of synthetic fiber filament yarns and made to have substantially the same elongation at break as the covering layer.
The covering layer can be formed by plaiting the plurality of silk strands and made to have substantially the same elongation at break as the core.
The synthetic fiber filament yarn can be made of any of various materials such as nylon, polyester, polypropylene and acrylic, among which polyester which has high breaking strength per denier is especially desirable from the viewpoint of giving improved strength to the suture.
The suture of the present invention has a suitable flexibility due to the rigidity of the core of synthetic fiber filament yarn and because of the flexibility of the covering layer of silk strands, and is thereby given high amenability to the correction of deformation such as the curl due to winding on reels and made easy to handle, hence outstanding advantages. The suture has another advantage; that it is readily deformable to a form suited to suturing during surgery. These great advantages appear attributable also to the fact that slippage occurs more smoothly between the synthetic fiber filament yarn core and the silk strand covering layer than between silk strands.
In the case of the suture already proposed (Japanese Utility Model Application No. 41670/1987) comprising a core of synthetic fiber filament yarn, the filament yarn generally has a higher elongation at break than the silk strands, so that when the suture is stretched under tension, the silk strands reach the limit of elongation (elongation at break) and break first. The force thereafter acts only on the filament yarn to break the yarn. Consequently, the overall breaking strength of the suture is lower than the sum of the individual breaking strengths of the yarn and the silk strands. According to the invention, on the other hand, the core of synthetic fiber filament yarn has substantially the same elongation at break as the covering layer of silk strands, with the result that when the suture breaks under tension, both the core and the covering layer break at the same time. Thus, the sum of the individual breaking strengths of the two is substantially equal to the overall breaking strength of the suture. In this case, synthetic fiber filaments increase in modulus of elasticity as they are made smaller in elongation at break by adjustment through thermal drawing. Accordingly, when the suture comprising such synthetic fiber filaments is compared with the suture comprising usual synthetic fiber filaments, the tensile force acting on the suture when the silk strands are stretched to break is greater on the former suture than on the latter by an amount corresponding to the increase in the modulus of elasticity. Thus, the former suture has a corresponding higher breaking strength. Moreover, the suture has further increased breaking strength because the synthetic fiber filament has higher breaking strength with a decrease in elongation at break. Because of the improved strength, sutures of small diameter are usable for wider application and are advantageous in avoiding injuries to the tissues of the human body to be sutured.
The reduction in the elongation at break gives somewhat increased rigidity to synthetic fiber filaments, makes them more suitable to use and is advantageous in facilitating correction of the deformation of the suture rendering the suture handleable with greater ease.
In the case where the core is formed of synthetic fiber filament yarns extending substantially parallel to one another, it is desirable that the filament yarns be at least 18% to not greater than 24%, more preferably at least 19% to not greater than 21%, in elongation at break because silk strands are generally 18to 19% in elongation at break and exhibit an elongation at break of 18 to 24%, usually 19 to 21%, when formed into a covering layer by plaiting and so on.
When the core is prepared from synthetic fiber filament yarns by single twisting, plying or plaiting, the core thus formed is adapted to have the same elongation at break as the covering layer, and the elongation is suitably determined in view of twisting or plaiting density, strength, etc.
When the suture to be obtained has a relatively large size of USP2-0 or greater, it is especially desirable to form the core by plying the yarns so that the first twist and the final twist are in opposite directions to offset the torques due to the twists. For sutures of relatively small size of USP3-0 or smaller, single twisting achieves satisfactory results. Although the number of twists for the core is preferably greater to give improved breaking strength to the suture, the filament yarns may be loosely twisted with about 20 to about 50 T/m when made into a compacted ply.
To assure facilitated correction of deformation and improved breaking strength, it is desirable for the suture to have the core in a greater proportion as will become apparent from the following embodiments, especially from the results given in Table 1.
The present invention will become more apparent from the embodiments to be described below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view partly broken away showing a suture embodying the invention;
FIG. 2 is a view in section taken along the line A--A in FIG. 1;
FIG. 3 is a perspective view showing a core of another embodiment; and
FIG. 4 is a graph showing the relationship between the load and the elongation, as determined for the suture of the invention and a conventional suture and involving a break.
DETAILED DESCRIPTION OF INVENTION
Embodiment 1
Silk strands were each prepared from two scoured silk yarns substantially of 27 denier (median of fineness values involving usual variations) by twisting the yarns together in S direction at about 300 T/m (s27 Naka/2). Silk strands of another type were also prepared each from two silk yarns, the same as those used above, by twisting the yarns together in Z direction at about 300 T/m (z27 Naka/2). A plied yarn serving as a core was prepared by twisting together eight polyester filament yarns (product of Teijin Limited, T300s, 20 denier, composed of 6 filaments, 19% in elongation at break) in S direction at 200 T/m to obtain a twisted unit, and twisting three such twisted units together in Z direction at 137 T/m. The core thus obtained was about 20% in elongation at break. The core was then sheathed with a covering layer by arranging the two types of silk strands alternately on a braiding machine and plaiting the strands, 16 in total number, into a braid at a density of 26 stitches/cm, whereby a suture of USP1-0 in size was obtained. The covering layer formed was about 20% in elongation at break.
The structure of the suture obtained is shown in FIG. 1, in which indicated at 1 is the covering layer formed by plaiting the silk strands, and at 2 is in the core of plied polyester yarn.
The suture prepared in this way had a breaking strength of 2.92 kgf which was 11% higher than that of conventional sutures made of silk yarns only and having the same size. The suture had suitable flexibility (i.e. suitable stiffness), was highly amenable to deformation such as curling and can easily be handled free of trouble. Embodiment 2
A single twist yarn serving as a core 2' as shown in FIG. 3 was prepared from three polyester filament yarns (product of Toray Industries, Inc., S200, 20 denier, composed of 6 filaments, 19% in elongation at break) by twisting the yarns together in S direction at 200 T/m. The core obtained was about 19% in elongation at break. The core 2' was then sheathed with a covering layer which was formed in the same manner as in Embodiment 1 by plaiting twelve silk strands into a braid at a density of 29 stitches/cm, whereby a suture of USP4-0 in size was obtained. The covering layer was about 19% in elongation at break.
The suture thus obtained and having a small size also exhibited excellent characteristics like the suture of Embodiment 1.
Other Embodiments
Sutures of varying sizes were prepared in the same manner as above and tested in comparison with conventional sutures. The results are shown in Table 1, in which the sutures of USP1-0 and USP4-0 in size were made of materials different from those of Embodiments 1 and 2. Accordingly, these sutures were slightly different from the above sutures in the results achieved.
TABLE 1__________________________________________________________________________USP size 2 1 1-0 2-0 3-0 4-0 5-0 6-0__________________________________________________________________________InventionNumber of component 16 16 16 16 12 12 8 6strands of covering layerCore ratio (%) 47 33 33 33 20 20 11 14Elongation of break (%) 27.8 25.0 23.7 22.2 20.3 20.0 19.4 18.5Breaking strength (kgf) 6.05 3.88 2.92 2.27 1.48 0.95 0.58 0.30Flexibility (cm) 18.5 17.5 17.0 17.0 16.0 15.5 12.0 11.0PriorBreaking strength (kgf) 5.68 3.76 2.86 2.18 1.41 0.91 0.54 0.28Art APriorNumber of component 16 16 16 16 12 12 8 6Art Bstrands of covering layerCore ratio (%) 15 15 15 15 4 4 0 0Elongation at break (%) 29.9 27.1 25.2 23.8 22.4 21.8 20.2 19.1Breaking strength (kgf) 4.94 3.50 2.79 2.04 1.30 0.83 0.46 0.25Flexibility (cm) 16.0 15.0 1.5.5 15.0 14.0 11.5 9.5 8.0__________________________________________________________________________
With reference to Table 1, the core ratio is the ratio of the core to the entire suture in weight as expressed in percentage. The flexibility was determined according to the method of JIS L-1096A. Prior Art (prior-art suture) A was prepared in the same manner as the suture of the invention except that a usual polyester filament yarn (24% in elongation at break) was used as the core. Prior Art (prior-art suture) B had a silk yarn as the core.
The suture of the invention and a conventional suture comprising a core of usual synthetic fiber filament yarn, both USPI in size, were subjected to a tensile test. FIG. 4 is a graph showing the results. The graph reveals that the suture of the invention has exceedingly higher breaking strength (peak value). The graph also shows that with the conventional suture, the descending line representing a break has an intermediate peak, which indicate that the break involves a time lag between the core and the covering layer. With the suture of the invention, the descending line extends downward almost straight, indicating that the core and the covering layer broke at the same time.
When actually used for operations by surgeons, the sutures of the above embodiments were evaluated as being highly amenable to the correction of curls and like deformations, suitably flexible (suitably stiff), easy to handle to assure an efficient operation and free of any break during handling even when of a reduced size.
The suture of the invention is not limited to the foregoing embodiments but can be modified variously within the scope of the invention defined in the appended claims.
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A suture comprising a core of at least one synthetic fiber filament yarns, and a covering layer formed of a plurality of silk strands and sheathing the core, the core and the covering layer having substantially the same elongation at break. The filament yarns have increased modulus of elasticity and increased breaking strength to thereby give the suture improved breaking strength and also have enhanced rigidity to render the suture highly amenable to the correction of its deformation and easier to handle.
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FIELD OF THE INVENTION
[0001] This invention relates generally to a method and apparatus for mixing systems that for the improvement of flow deep into conical or cone geometry tanks, for example. More particularly, the present invention relates, for example, to an improved directional or draft tube system or the like, for use with mixing conditions utilizing vessels having cone geometries, for example.
BACKGROUND OF THE INVENTION
[0002] Mixing tank arrangements for processing liquid and solid material sometimes employ a draft tube or directional tube apparatuses, or the like to assist with flow of solid suspension mixing. The mixing tank arrangements typically employ a down-pumping impeller near the top of the draft tube along with flow control vanes near the down-pumping impeller. Typical draft tube designs utilized in the art also may include vertical slots extending from the bottom or bottom rim of the draft tube to above the level to which solids may settle. The vertical slots function to allow the startup of the mixing tank in conditions where the solids have settled by solids by enabling the solids that have settled in the mixing tank, due to inactivity of the mixing tank, to pass through the tops of the vertical slots. The flow of the settled solids through the tops of the vertical slots usually functions to scour away and re-suspend the settled solid material in the tank region adjacent the vertical slots.
[0003] Many processes require suspension of solid particles in a liquid within a tank. Mixing tank arrangements utilizing a draft tube are commonly used to accomplish the aforementioned suspension as previously discussed above. Oftentimes circumstances arise which require that these mixing processes be shut down or halted for various reasons and long periods of time. During these shut-down times or periods of inactivity, the solids that are suspended in the liquid mixture begin to settle at the bottom of the mixing tank. As previously discussed, draft tubes often extend into the mixing vessel in which they are disposed so that their lower ends are submerged in, or extend into, the settled solids. This orientation or positioning of the draft tube wherein the lower end of the draft tube is submerged, oftentimes causes difficulty during startup of the mixing vessel. This difficulty oftentimes is the result of the settled solids clogging the lower end of the draft tube, preventing the impeller from being started.
[0004] Methods currently employed in the art that address the aforementioned startup problem include first, draining the mixing vessel and removing or shoveling the settled solid material away from the bottom of the draft tube to clear the opening in the bottom of the draft tube. Once the opening of the draft tube is cleared, the mixing vessel is refilled with the liquid and the impeller is started and the solids are then added back to the mixing vessel.
[0005] Another method currently employed in the art is to set up and arrange pipes that extend to the bottom of the mixing vessel. These pipes proceed to extend into the vessel and into the bottom region of the draft tube. Next, pressurized or compressed air is provided or forced through the pipes to agitate and loosen the settled solids. The compressed air enables the liquid to move through solid material and begin to scour away and suspend and/or re-suspend the particles of the settled solids.
[0006] Still another method currently used in mixing assemblies or mixing apparatuses is to limit the length of the draft tube and not extend the draft tube a specified distance. For example, in these arrangements, the draft tube extends into the mixing vessel however it does not extend into or below the level of the settled solids.
[0007] The aforementioned solids re-suspension methods and apparatuses have drawbacks however. Some methods and apparatuses, as previously discussed, require expensive auxiliary equipment adding cost while others require shut-down time which also adds cost to the operation of the mixing vessel. Furthermore, when solids loading of the mixing vessel is increased, oftentimes the impeller is unable to provide the necessary head to overcome the mixing system resistance. In these increased solids loading conditions, re-suspension may cause the mixing system power requirements to increase until possible overload of the motor driving the impeller. Furthermore, in draft tube systems similar to the ones previously described, motor overloads and subsequent process failure may be experienced in start up conditions having high concentration of settled solids. This is oftentimes due to mixing systems lacking significant enough velocity head to break the interface between the liquor and the settled solids without overloading or short circuiting the mixing system flow pattern.
[0008] Another drawback to the above-discussed draft tube arrangements is that they are often utilized in flat-bottom mixing vessels and are not conducive to being employed with cone shaped or conical shaped vessels. Cone shaped or conical shaped vessels are oftentimes preferred in mixing applications such as pharmaceutical applications and/or mining slurry applications where it is advantageous to easily drain the contents of the mixing vessel.
[0009] Accordingly, there is a need in the art to provide an directional tube apparatus and method for the mixing of solids and slurries or the like, in vessels have non-flat bottom vessels. More specifically, it is desirable to provide a directional tube apparatus for use with cone shaped and conical shaped mixing vessels.
SUMMARY OF THE INVENTION
[0010] The foregoing needs are met, to a great extent, by the present invention, wherein aspects of a mixing assembly start-up method are provided.
[0011] In accordance with an embodiment of the present invention, a mixing assembly for mixing settled solids in a liquid or the like, having a longitudinal axis is provided, comprising: a mixing vessel comprising: a first upper wall that extends generally parallel to the longitudinal axis; a second upper wall that extends generally parallel to the longitudinal axis and opposes sais first upper wall a first lower wall that extends from said first upper wall that extends toward the longitudinal axis away from said first upper wall; a second lower wall that extends from said second upper wall that extends toward the longitudinal axis away from said second upper wall, wherein said first and second lower walls meet at an apex; a directional tube having a first end and a second end wherein said second end, wherein said directional tube further comprises at least one slot located proximate to said second end wherein said at least one slot extends generally normal to the longitudinal axis; and a first impeller disposed within said directional tube, connected to a rotatable shaft.
[0012] In accordance with another embodiment of the present invention, a method for suspending or mixing solids in a liquid using a mixing assembly having a longitudinal axis is provided, comprising: a mixing vessel comprising: a first upper wall that extends generally parallel to the longitudinal axis; a second upper wall that extends generally parallel to the longitudinal axis and opposes said first upper wall a first lower wall that extends from said first upper wall that extends toward the longitudinal axis away from said first upper wall; a second lower wall that extends from said second upper wall that extends toward the longitudinal axis away from said second upper wall, wherein said first and second lower walls meet at an apex; a directional tube having a first end and a second end wherein said second end, wherein said directional tube further comprises at least one slot located proximate to said second end wherein said at least one slot extends generally normal to the longitudinal axis; and a first impeller disposed within said directional tube, connected to a rotatable shaft, said steps comprising: rotating the first impeller in a first rotational direction for a first period of time, wherein said rotating of the impeller in the first rotational direction causes the liquid to flow in a first axial direction along the longitudinal axis through the directional tube away from the first end and out through the at least one slot; and forcing the fluid through to contact the apex as it exits the at least one slot.
[0013] In accordance with yet another embodiment of the present invention, a mixing assembly for mixing settled solids in a liquid or the like, having a longitudinal axis is provided, comprising: a mixing means comprising: a first upper wall that extends generally parallel to the longitudinal axis; a second upper wall that extends generally parallel to the longitudinal axis and opposes sais first upper wall a first lower wall that extends from said first upper wall that extends toward the longitudinal axis away from said first upper wall; a second lower wall that extends from said second upper wall that extends toward the longitudinal axis away from said second upper wall, wherein said first and second lower walls meet at an apex; a directional means having a first end and a second end wherein said second end, wherein said directional means further comprises at least one slot located proximate to said second end wherein said at least one slot extends generally normal to the longitudinal axis; and a first agitator disposed within said directional means, connected to a rotatable shaft, said steps comprising: means for rotating the first agitator means in a first rotational direction for a first period of time, wherein said means for rotating of the agitator in the first rotational direction causes the liquid to flow in a first axial direction along the longitudinal axis through the directional tube away from the first end and out through the at least one slot; and means for forcing the fluid through to contact the apex as it exits the at least one slot.
[0014] There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
[0015] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
[0016] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic cross-sectional view of a mixing assembly having a directional tube in accordance with an embodiment of the present invention.
[0018] FIG. 2 is a schematic view of the mixing assembly depicted in FIG. 1 during operation in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION
[0019] Various preferred embodiments of the present invention provide for a re-suspending of settled solids, such as alumina, in mixing systems or the like. It should be understood, however, that the present invention is not limited in its application to mixings systems or the suspension of alumina, but, for example, may be used with other processes and/or apparatuses requiring the suspension or re-suspension of solids. Preferred embodiments of the invention will now be further described wither reference to the drawing figures, in which like reference numerals refer to like parts throughout.
[0020] Referring now to FIG. 1 , a mixing assembly, generally designated 10 , is depicted for mixing a liquid in which a solid material is suspended. The mixing assembly 10 includes a mixing vessel 12 and a directional tube or draft tube 14 positioned at a central location within the mixing vessel 12 . The mixing assembly 10 also includes an upper impeller 16 that is sized for the process for which the assembly is being utilized. This upper impeller 16 may be a radial impeller, up-pumping impeller, down pumping impeller or any combination thereto. As illustrated in FIG. 1 , the impeller 16 is connected to a rotatable shaft 18 which is in turn connected to a gear drive which is driven by a motor (each not pictured). The motor and gear drive operate to rotate or turn to drive the shaft.
[0021] As illustrated in FIG. 1 , the assembly 10 further comprises a second impeller 20 attached to the shaft 18 . As depicted, the impeller 20 is disposed within the directional or draft tube 14 . In one embodiment of the present invention, the impeller 20 is preferably an axial down pumping impeller however depending upon the process in which the assembly 10 is used, alternative impellers may be employed. As previously, discussed, the impeller 20 is mounted to the shaft 18 , however a steady bearing 22 may be provided to assist with support and stabilization of said shaft 18 and impeller 20 .
[0022] The aforementioned motor and drive mechanism operate such that they can drive the shaft 18 in a first direction so that the second impeller 20 pumps, or down pumps, liquid material downward through the directional or draft tube 14 . The motor and drive mechanism may also operate in an alternative mode to rotate or turn the shaft 18 in an opposite, second direction so that the second impeller 20 pumps, or up pumps, the liquid material upward through the directional or draft tube 14 .
[0023] Turning now more specifically to directional or draft tube 14 , the directional or draft tube 14 is conduit attached or mounted to the vessel 12 . Preferably, the directional or draft tube 14 is mounted to the vessel 14 such that it extends vertically above the apex 24 of vessel 14 . As illustrated in FIG. 1 , the vessel 14 has a diameter “T” whereas the conduit has a diameter D T . In one preferred embodiment of the present invention, D T /T is greater than or equal to 0.03 and equal to 0.7. In another embodiment of the present invention, D T /T is approximately 0.2 to approximately 0.3.
[0024] As depicted in FIG. 1 , the directional or draft tube 14 has a series of radial cut-outs or slots 26 perforating the lower portion of the wall of the directional or draft tube 14 . Preferably, said slots 26 positioned in the vicinity or adjacent the apex of the vessel 12 . Depending upon the application, the directional or draft tube 14 may employ more or less slots 26 . Moreover, depending upon the application, the slots may vary in size and geometry.
[0025] For example, the slots can have a tapered geometry. This exemplary geometry of the slots 26 can provide less resistance to liquid flow. The above-described slots 26 typically allow for a the apex 24 area of the vessel 12 to be sufficiently mixed during operation. This orientation also allows for the desired scouring away and clearing of the settled solids at the bottom of the mixing vessel 12 .
[0026] Turning now to FIG. 2 , during standard operation of the mixing assembly 10 , the mixing vessel 12 is charged with liquid such as liquor and solid material such as alumina and the impeller 20 is driven in the aforementioned first direction. During standard operation, the rotation of the impeller 20 down pumps, forcing a jet stream of liquid downward through the inside of the directional or draft tube 14 toward the bottom of the mixing vessel 12 as indicated by the arrow. As the liquid is forced downward through the directional or draft tube 14 , the flow or jet stream approaches the bottom of the mixing vessel 12 where it is turned and deflected upward and outward, as indicated by arrows, creating a flow rising around the apex 24 of the mixing vessel 12 .
[0027] The above-described flow pattern that exists during the standard operation of the mixing assembly 10 functions to scour away and maintain the liquid suspension of the solid materials that tend to settle in conical or cone shaped mixing vessels. As the liquid flow approaches the top of the directional or draft tube 14 , the liquid with solid material suspended therein, may flow inward toward the directional or draft tube 14 away from the outer walls of the vessel 12 . It again is pumped downward through the directional or draft tube 14 , as previously described, in continuous circulation within the mixing vessel 12 .
[0028] The assembly 10 may be alternatively operated in an alternative mode as previously discussed. By alternative mode, it understood that the impeller 20 is driven or operated in the reverse or the opposite direction than during standard operation of the mixing assembly 10 . The impeller 20 is rotated in the reverse direction, causing upflow from the suction head within the directional or draft tube 14 . This action creates a head differential. The resulting flow will discharge as a swirling area of liquor (flow) in the tank and the draft tube liquor initially begins to re-suspend the settled solids. The aforementioned re-suspension of the settled solids provides a higher density liquor which is capable of breaking through the liquid-solid interface of the mixing system 10 that results from the settling of the solids. The aforementioned re-suspension of the settled solids also functions to re-suspend a portion of the settled solids so as to uncover the slots 26 of the directional or draft tube 14 .
[0029] The above-described operation of the mixing assembly 10 in the alternative mode, i.e., with the impeller 20 driven or operated in the reverse or the opposite direction than rotation during standard operation, enables the mixing assembly 10 to be started in conditions having high concentration of settled solids. The above-described operation of the mixing assembly 10 in the alternative mode also prevents the likelihood of motor overload during start-up of the mixing assembly 10 due to high head conditions which can be caused by high system head resulting from the high concentration of settled solids.
[0030] The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A mixing assembly for mixing settled solids in a liquid or the like, having a longitudinal axis, comprising: a mixing vessel having an apex. The assembly includes a directional tube having a first end and a second end wherein said second end, wherein the directional tube further comprises at least one slot located proximate to said second end wherein said at least one slot extends generally normal to the longitudinal axis. The assembly further includes an impeller disposed within the directional tube, connected to a rotatable shaft.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage application of International Application No. PCT/EP2007/051959 filed Mar. 1, 2007, which designates the United States of America, and claims priority to German application number 10 2006 022 357.8 filed May 12, 2006, the contents of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The invention relates to a method or a device for determining the gas composition of a fuel tank of a motor vehicle filled with a CNG mixture.
BACKGROUND
[0003] It is already known that motor vehicles equipped with an Otto engine can be operated with a natural gas, known as CNG (Compressed Natural Gas). The CNG mixture is also known as natural gas. With the appropriate equipment, such a CNG motor vehicle can be operated either exclusively with natural gas (monovalent operation) or as a bi-fuel variant with the option of gasoline or natural gas operation. The natural gas is heavily compressed at high pressure of around 200 bar and fed into one or more pressurized fuel tanks in the motor vehicle. The main component of natural gas is methane (CH 4 ) with 85-98%. In addition however natural gas also contains significant proportions of higher hydrocarbons such as ethane (C 2 H 6 ), propane (C 3 H 8 ) and butane (C 4 H 10 ). This is then referred to as a wet natural gas. The reason for this lies in the fact that the ethane, propane and butane components have a relatively low vapor pressure and thus vaporize quickly under pressure. The vapor pressure at 20° C. amounts to around 38 bar for ethane, 8.5 bar for propane and 2.0 bar for butane. Methane, the main component of the natural gas, only has a vapor pressure of 1.47 bar at a temperature of minus 157° C.
[0004] If the fuel tank is filled with the CNG mixture at high pressure, it is essentially methane that is available in a gaseous form, with the ethane, propane and butane components mostly being present in a liquid phase. These liquid components collect on the floor of the fuel tank and are not used while the gas pressure in the fuel tank is greater than the vapor pressure of ethane, propane or butane. If on the other hand the gas pressure in the fuel tank reaches the value of the vapor pressure of ethane, then the liquid ethane proportion evaporates first, for which the vapor pressure at 20° C. lies at around 38 bar. If the gas pressure in the fuel tank falls further, then at 8.5 bar the propane proportion and finally at 2 bar the butane proportion evaporate. The result of this physical behavior is that when the gas mixture is injected into the internal combustion engine in conjunction with the induced air, the chemical composition of the gas mixture changes continuously. With a full fuel tank a pure methane-air mixture is injected or burned, with the gas pressure in the fuel tank (system pressure) falling continuously. When the vapor pressure of ethane is reached at around 38 bar, this begins to evaporate and a mixture of methane and ethane is produced. The system pressure remains constant until such time as the ethane proportion in the fuel tank is evaporated. Subsequently the system pressure falls further. When the system pressure reaches the vaporization threshold of propane at around 8.5 bar. the liquid propane proportion evaporates. As from this point a fuel mixture of methane, ethane and propane is burned.
[0005] As the tank is emptied further, the butane proportion also evaporates at appr. 2 bar. In practice the latter situation will hardly ever occur since as a rule the injection pressure in the cylinder of the internal combustion engine is driven to over 2 bar and thus the butane proportion remains liquid and in such cases accumulates continuously in the fuel tank.
[0006] Since the different components of the CNG have different energy contents, significant effects emerge for the operating behavior of the internal combustion engine in relation to the cylinder filling, the mixture formation, the duration of the fuel injection and the combustion. The exhaust gas emissions can also be especially influenced by this.
SUMMARY
[0007] The gas injection into the combustion chamber of an internal combustion engine can be improved, taking into account the current composition of the CNG in the fuel tank. According to an embodiment, a method for determining the gas composition of a fuel tank of a motor vehicle filled with a CNG mixture, may comprise the steps of permanently measuring the gas pressure and the gas temperature in the fuel tank of the motor vehicle, wherein an algorithm is used to determine from the measured temperature and the measured gas pressure in the fuel tank the current vapor pressure of at least one component of the CNG mixture, especially for methane, ethane, propane and/or butane, and if the gas pressure of one of the components of the CNG mixture in the fuel tank falls below a threshold, a corresponding current composition of the gas mixture is determined.
[0008] According to a further embodiment, the current vapor pressure of a component of the CNG can be taken from a stored table or pressure curve. According to a further embodiment, on further withdrawal of gas packets, the start of evaporation of one of the components of the CNG can be taken from the horizontal pressure characteristic of the stored pressure curve. According to a further embodiment, the computation of the gaseous methane amount (m methane ) can be calculated immediately before the evaporation of ethane according to the formula
[0000] m methane =p d *V/ ( R methane *T ),
[0000] with p d being the vapor pressure, V the gas volume, R methane a gas constant and T the gas temperature in the fuel tank. According to a further embodiment, the vapor pressure p d can be calculated according to the formula
[0000] p dethane =ρ ethane *R ethane *T.
[0000] with T being the gas temperature in the fuel tank, R a gas constant and ρ the gas density. According to a further embodiment, a mixed gas constant
[0000] R Mix =( m methane *R methane +m ethane *R ethane )/( m methane +m ethane )
[0000] can be computed for further gas packages of methane and ethane withdrawn. According to a further embodiment, the gas volume V in the fuel tank can be computed according to the formula
[0000] V =(Δ m methane *R methane )/( P 1 /T 1 −P 2 /T 2 )
[0000] According to a further embodiment, the measured vapor pressure can be compared with the computed required value.
[0009] According to a further embodiment, the amount of gas to be injected for the internal combustion engine of the motor vehicle can be adapted depending on the current gas composition. According to a further embodiment, the amount of gas to be injected into an internal combustion engine, can be adapted taking into account the current gas composition in the fuel tank and/or its energy value in relation to a modelled consumption behavior of the internal combustion engine. According to a further embodiment, the duration of the injection and/or the ignition angle can be adapted. According to a further embodiment, the ignition angle can be adapted to current operating conditions of the internal combustion engine, especially in the start phase, while the engine is warming up and/or during lean-burn operation. According to a further embodiment, a calculation can be made to check the volume, in which case, assuming a known amount of methane gas, a fall in pressure in the fuel tank is measured, from which the specified tank volume can be deduced. According to a further embodiment, with a parked motor vehicle if ambient conditions change, especially the temperature and/or the gas pressure in the fuel tank a new composition of the gas mixture can be computed and the new composition of the gas mixture can accordingly be taken into consideration when the engine is started again.
[0010] According to another embodiment, a device for determining the composition of the gas mixture of a fuel tankfilled with a CNG mixture, may comprise a program-controlled processing unit, wherein the processing unit is operable to determine the gas composition with the aid of an algorithm and using a measured temperature and gas pressure in the fuel tank.
[0011] According to a further embodiment, the processing unit may be part of an engine management device present in the motor vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] An exemplary embodiment of the invention is shown in the drawing and will be explained in greater detail in the description given below.
[0013] FIG. 1 shows a block diagram of a device according to an embodiment for determining the gas composition,
[0014] FIG. 2 shows a first diagram with a pressure curve,
[0015] FIG. 3 shows a second diagram and
[0016] FIG. 4 shows a flowchart for the device according to an embodiment.
DETAILED DESCRIPTION
[0017] The method for determining the gas composition or the device according to various embodiments may have the advantage that, independently of the prevailing gas pressure (system pressure) in the fuel tank, a gas mixture is always made available which, with a current engine requirement, corresponds to the specified setpoint value. This enables not only the power curve of the internal combustion engine to be improved, but in particular the exhaust gas emission to be optimized as well. This is especially achieved in that, with the aid of an algorithm, the current vapor pressure of at least one component of the CNG mixture, especially for ethane, propane and/or butane, is able to be determined. When the vapor pressure of one of the said components falls below a lower threshold a corresponding current composition of the gas mixture is established.
[0018] The measures specified in the dependent claims provide advantageous developments and improvements of the method specified in claim 1 . It is viewed as especially advantageous that the current vapor pressure of a component of the CNG can be taken very easily from a previously stored table or pressure curve. Since the temperature and the gas pressure in the fuel tank are measured continuously, with further ongoing gas removal the current vapor pressure of ethane for example can be taken from the horizontal curve part of the stored pressure curve.
[0019] Also useful is the fact that the gaseous methane amount, which is withdrawn immediately before the evaporation of ethane, can be computed with a very simple formula.
[0020] The vapor pressure can be computed with a further formula if the gas temperature in the fuel tank, the gas constant and the gas density are known.
[0021] An important variable is the knowledge of the gas volume in the fuel tank. Furthermore a very simple formula allows the volume to be checked. Then a drop in pressure occurs in the fuel tank when a known amount of methane fuel is withdrawn.
[0022] To validate measurement and computation there is provision for the measured vapor pressure (actual value) to be compared with the computed setpoint value. An error can be identified very easily in this way.
[0023] Another advantage of the various embodiments can also be seen in that the amount of gas to be injected for the internal combustion engine of the motor vehicle is adapted as a function of the current gas composition. In particular this allows energetic differences of the gas components to be compensated for. It is also viewed as especially advantageous that the amount of gas to be injected is adapted taking into account its energy content in relation to the modelled fuel consumption behavior of the internal combustion engine. This adaption can for example be made by the adjustment of the ignition angle and/or alternately by changing the injection duration and thus the amount of fuel injected. In particular these adaptations can be performed for example in the start phase, when the engine is warming up and/or during lean-burn operation.
[0024] A very advantageous solution is also seen in the fact that, when a motor vehicle is parked, a new value is computed for the gas composition, especially if the ambient conditions, above all the temperature and/or the gas pressure in the fuel tank, have changed. The newly determined gas composition is then taken into account accordingly when the engine is next started.
[0025] Finally the various embodiments also may have the advantage that the device for determining the gas composition features a program-controlled processing unit. With this processing unit, with the aid of an algorithm and using the temperature and the gas pressure measured in the fuel tank, the gas composition can be determined very easily and without any great computing effort. In such cases it has proved to be particularly advantageous for the processing unit to be integrated into an engine control device which is already present in the motor vehicle. The available engine control unit merely needs an appropriate software program with which the methods according to various embodiments can be realized.
[0026] The block diagram of FIG. 1 shows an exemplary embodiment, in which an internal combustion engine 1 is connected to an injection system 3 . The internal combustion engine 1 is embodied as an Otto engine. The Otto engine in such cases can be embodied monovalent for combustion of the CNG or in bivalent operation for switching between gasoline injection or gas injection. The gas is injected by means of the injection system 3 . The injection system 3 is connected via a hydraulic line 7 to a fuel tank 2 in which the CNG mixture is stored. The fuel tank 2 is a embodied to resist high pressure so that it withstands the usual filling pressure of up to 200 bar. Because of the high gas pressure the CNG mixture is partly stored in the liquid state. The CNG mixture contains 85-98% Methane as its main component, which because of a vapor pressure is present in gaseous form. The components ethane, propane and butane exhibit a significantly lower vapor pressure so that these proportions are stored in liquid form in the fuel tank 2 .
[0027] Furthermore a pressure sensor 4 and also a temperature sensor are arranged in or on the tank. These sensors 4 , 5 continuously measure the temperature T as well as the gas pressure (system pressure) P within the fuel tank 2 . The measured values are transferred via corresponding electrical lines to a processing unit 6 . As a result of the data received the processing unit 6 computes a current composition of the gas within the fuel tank 2 or the gas system, with the aid of an appropriate algorithm which will be explained in greater detail below. The processing unit 6 essentially has a control program with which the various parameters, for example the vapor pressure of a component of the CNG mixture, the tank volume, the gas composition etc. are calculated.
[0028] In an alternate embodiment the processing unit 6 is integrated into an engine control device which is present in any event for control of the internal combustion engine.
[0029] The functioning of this arrangement is explained in greater detail with reference to the first diagram of FIG. 2 . The diagram shows a pressure curve on which the gas pressure p in the fuel tank, as measured by the pressure sensor 4 , is plotted on the Y axis. The timing of the gas pressure p which is measured by the pressure sensor 4 is plotted on the X axis. The fuel tank in this case is filled with the CNG mixture, with the CNG mixture, in addition to methane, also including the components ethane, propane and butane. It is assumed that the fuel tank is filled at a gas pressure of 200 bar. The pressure curve shown in FIG. 2 shows an example of the ratio between the components methane, ethane and propane. The pressure curve would continue in a similar manner for the butane proportion.
[0030] With the aid of the available pressure and temperature sensors the gas temperature and the gas pressure are measured continuously in the fuel tank. Simultaneously the vapor pressure of ethane is computed in the processing unit. The computation of the vapor pressure of ethane can alternatively also be determined from the pressure curve shown in FIG. 2 , since the time at which the evaporation of the ethane proportion begins can be taken from the point at which it reaches the vapor pressure value at around 38 bar. This part corresponds to the part of the curve 2 running horizontally. The falling part of the curve 1 , which runs between at the pressure values of 200 and 38 bar, by contrast specifies that in this pressure range only the methane gas is present since the other components of the gas mixture are present in their liquid phase in the range below 38 bar On reaching the gas pressure or 38 bar ethane begins to evaporate so that, despite the further removal of gas, the gas pressure in the fuel tank does not fall any further but also does not rise. This can be seen from the fact that the curve runs horizontally 2 . Since the pressure in the fuel tank generally drops very slowly this point of the part of the curve 2 can be determined more simply and more precisely if knowledge of the vapor pressure is available. On the other hand the vapor pressure value determined from the curve shape can conversely be compared to the calculated value in order especially to check the measurement accuracy and thereby exclude a possible error. This allows the system security to be increased in an advantageous manner.
[0031] The vapor pressure is defined by the following formula
[0000]
p
d
=ρ*R*T
[0000] with p d being the vapor pressure, ρ the gas density, R a gas constant and T the gas temperature.
[0032] If the case now arises in which the fuel tank is emptied far enough for the pressure to fall below the vapor pressure p d =38 bar of ethane, the processing unit or the engine management device reacts. The tank content at this point in time comprises the remaining gaseous components and the amount of liquid ethane collected in the past. At this vapor pressure of p d ≈38 bar ethane evaporates, so that the engine now burns a gas mixture of methane, ethane and air, with its energy content differing from that obtaining when pure methane combustion is taking place. The amount of gas to be brought into the cylinder must be adapted according to the current gas mixture quality to cater for the changed chemical composition of the fuel (X % methane, Y % ethane) and to maintain the defined air-fuel ratio. The composition of the gas mixture and thus the injection amount to be set by the engine management device changes continuously. The change occurs until such time as the entire ethane proportion has evaporated. As well as the adaptation of the injection amount, further adaptations are undertaken especially when the internal combustion engine is started, while it is warming up and above all during lean-burn operation. In particular the ignition angle can be adjusted and/or the duration of the injection can be adapted in accordance with the energy content or the calorific value of the gas mixture. Furthermore the modelled injection behavior of the engine is to be corrected in accordance with the current composition of the gas mixture.
[0033] While ethane is evaporating, the system is balanced and the tank pressure remains constant, as can be seen from curve part 2 of FIG. 2 . Only when the entire ethane proportion is evaporated does the tank pressure continue to fall further in accordance with curve part 3 .
[0034] The computation of the composition of the gas mixture for the period in which methane and ethane are present in their gaseous state is explained in greater detail below.
[0035] As can also be seen from FIG. 2 , the evaporation of the gas components for propane occurs in a similar way to the way previously described for ethane. If the tank pressure falls to around 8.5 bar, the liquid propane proportion then evaporates so that the pressure in the fuel tank remains constant in accordance with curve part 4 . Only if the entire propane proportion has evaporated and gas continues to be withdrawn does the gas pressure in the fuel tank continue to fall in accordance with curve part 5 .
[0036] A particular situation can arise if the vehicle is parked and if the ambient conditions, especially the temperature and the pressure conditions in the fuel tank, change while the vehicle is standing. Changes in temperature can for example cause the gas pressure in the fuel tank to become greater than the vapor pressure of a gas proportion. If the temperature falls the gas pressure can become less or constant with the vapor pressure. There is provision for these special cases for the amount of ethane or propane in vapor form to be recalculated. When the engine is started again the new composition of the gas mixture is then used as a basis.
[0037] In the other diagram of FIG. 3 the ratio between methane and ethane is shown on the Y axis. The amount of gas removed in kg is plotted on the X axis. It is evident from the falling branch of the methane/ethane curve that at higher gas pressure and smaller amount of gas removed the methane proportion in the gas mixture is up to 22 times greater than the ethane proportion. When only around 0.5 kg of the gas mixture is removed the methane proportion is only around three times as high as the ethane proportion. The methane proportion falls further so that for a mass of gas of around 3 kg removed, the ratio of methane to ethane is around 1:1. Based on this curve shape it is clear that the injection conditions for the internal combustion engine are continuously to be adapted to the current gas composition in the fuel tank.
[0038] The computation of the current gas mixture composition in the fuel tank is explained in greater detail below using a methane and ethane as an example. The amount of methane in the fuel tank at the point in time directly before the evaporation of methane, i.e. at the beginning of the horizontal curve part 2 ( FIG. 2 ) is computed with the following formula
[0000] m methane =p d *V/ ( R methane *T )
[0039] It is assumed that an amount of gas Δm is withdrawn in one working cycle. The amount of gas Δm to be withdrawn is assumed to be known. For example the value of Δm is determined from the mass of air sucked in and the corresponding λ value. The first gas to be withdrawn from the fuel tank is pure methane gas. The continuous withdrawal of gas finally causes the tank pressure to fall below the vapor pressure of ethane (appr. 38 bar). This causes as much ethane to evaporate as to reach the vapor pressure again.
[0040] The formula for calculating the first evaporated amount of ethane is as follows:
[0000]
m
ethane
=Δm*R
methane
/R
ethane
[0041] The further gas packages withdrawn contain both methane and also ethane. Thus a mixed gas constant R Mix is to be used, which corresponds to the composition of the gas mixture. The mixed gas constant R Mix is recalculated for each working cycle in accordance with the following formula
[0000] R Mix =( m methane *R methane +m ethane *R ethane )/( m methane +M ethane )
[0042] Each further evaporated ethane amount is calculated in accordance with the following formula
[0000]
m
ethane
=Δm*R
Mix
/R
ethane
[0043] The actual partial pressure p of ethane is calculated according to the formula
[0000]
p
ethane
=m
ethane
*R
ethane
*T/V,
[0000] with V being the current tank volume.
[0044] The current partial pressure p of methane is calculated in accordance with the following formula
[0000] p methane =P d P ethane
[0045] Furthermore the amount or a ethane currently present is calculated in accordance with the formula
[0000] m ethane =( P ethane *V )( R ethane *T )
[0046] The next gas package Δm withdrawn is composed of methane and ethane. In this case an ideal mixing of the gas is used as the starting point so that the gas package Δm can be calculated as follows:
[0000] Δm−Δm methane +Δm ethane
[0000] Δm methane −Δm*S/(1+S)
[0000] Δ m ethane =Δm *(1 −S/( 1 +S ))
[0047] This produces the current gas composition S in accordance with the formula
[0000]
S
current
=
m
methane
,
current
m
ethane
,
current
1
=
m
methane
,
old
-
S
alt
1
-
S
alt
-
Δ
m
current
m
ethane
,
old
-
(
1
-
S
old
1
+
S
old
)
·
Δ
m
current
+
R
Mix
,
current
R
ethane
,
current
·
Δ
m
current
1
[0048] By using at the previously calculated parameter values.
[0049] The calculation of the mixture composition is undertaken iteratively and is recalculated for each working cycle in which a gas mixture is withdrawn and a specific ethane proportion is evaporated.
[0050] The evaporation of liquid ethane means that the volume of the tank increases slightly and does so by precisely the proportion that ethane occupies in its liquid form. The factor ρ is the density of the liquid ethane (0.54 kg/l). This produces a change in volume ΔV
[0000] Δ V=Δm ethane ·ρ ethane
[0051] The current tank volume V is once again computed for each working cycle. This produces the following result
[0000]
V=V
old
+ΔV
[0052] An alternate calculation method is explained below. The alternate calculation method is physically equivalent to the calculation method mentioned previously. It has the advantage however that with this calculation method the processing unit can be presented in a structurally simpler way. In this alternate calculation method the current gaseous components of methane, mmethane and ethane methane are administered separately. The ratio X of the respective proportion to the overall amount of vapor is formed.
[0000] X methane = m methane m methane + m ethane X ethane =1 −X methan
[0053] The amount of gas injected per working cycle m is then made up as follows:
[0000] Δ m methane =X methane ·Δm
[0000] Δ m ethane =X ethane ·Δm
[0054] The respective proportions Δm methane and Δm ethane are then derived from the last Δm methane and Δm ethane values determined. This produces the following current amounts for methane and ethane:
[0000]
m
methane. current
=m
methane, old
−Δm
methane
[0000]
m
ethane, current
=m
ethane, old
−Δm
ethane
+Δm
ethane, evaporated
[0055] The amount of methane evaporating in a working cycle is then determined in a similar manner to that described previously.
[0056] If the gas pressure in the fuel tank falls below the vapor pressure of propane, propane evaporates and a fuel mixture of methane, ethane and propane is produced, as has previously been explained for FIG. 2 (curve parts 4 and 5 ). In this case the above formulae can be used in a similar manner. The only difference arising is that initially a fixed R Mix for the constant mass ratio of methane to ethane has to be calculated. For the rest of the calculation, instead of the values of methane, those of the mixed gas methane/ethane and instead of the value for ethane, that of propane is to be used.
[0057] Particular account should be taken of special cases which arise if the vehicle is parked and the external conditions, especially the ambient temperature and thereby the conditions in the tank change. A distinction is made between the following cases.
Case 1:
[0058] The temperature rises so far that ethane (or propane) which has already evaporated liquifies again. The gas pressure p is then greater than vapor pressure p d .
[0059] In this case pure methane is present in the gaseous state. The proportion of ethane is zero. The calculation is undertaken in the manner already described above.
Case 2:
[0060] The temperature has dropped so far that the entire proportion of ethane is evaporated. In this case the gas pressure p is smaller than the vapor pressure p d . The proportion of ethane is determined in this case as follows:
[0000]
m
ethane
=
(
p
·
V
T
-
m
ethane
·
R
methane
)
/
R
ethane
Case 3:
[0061] The temperature has risen or fallen so far that the vapor pressure currently predominates (p=p d ). This is merely a special case of case 2 and is treated exactly like case 2.
[0062] The way in which the volume of the tank is determined is explained below.
[0063] The tank volume is an important variable in the formulae given above. Depending on how large the proportion of liquid in gas components is, the value can vary. The volume is determined as follows. In the phase in which only methane is present in gaseous form, a specific amount Δm methane is burned. The amount Δm methane is known to the processing unit and can be calculated for example from the amount of air sucked in and the λ number. The withdrawal of the amount of fuel leads to a fall in pressure in the tank Δp=p 1 −p 2 . The tank volume can be computed from this. If the gas temperature changes while the fuel is being withdrawn, this change is also taken into account in accordance with the following formula:
[0000]
V
=
Δ
m
methane
·
R
methane
P
1
T
1
-
P
2
T
2
[0064] The flow diagram of FIG. 4 shows a flowchart for modeling the tank content. Initially, in box 10 and 11 the gas pressure in the fuel tank or the temperature in the fuel tank is determined with the aid of built-in sensors. The gas pressure or the gas temperature is then available in boxes 12 and 13 and is buffered. Subsequently, in box 14 the vapor pressure is computed in accordance with the following formula
[0000]
P
d
=ρ*R*T
[0000] which has been explained previously.
[0065] A check is performed in box 15 as to whether the current gas pressure in the fuel tank is less than the vapor pressure of a gas element. If it is not, the program returns to box 12 and the cycle is repeated. Otherwise, if the gas pressure in the fuel tank is less than the vapor pressure, the composition of the gas mixture is then computed in box 16 . Furthermore, in box 17 a current fuel consumption is computed and this value is taken into account when computing the composition of the gas mixture. Subsequently, in box 18 , depending on the current composition of the gas mixture, the injection is corrected accordingly.
[0066] This correction can for example be made by adjusting the ignition, especially the ignition angle, by changing the injection duration, by an induction manifold model calculation and/or suchlike. After this correction the program jumps back to box 12 and the cycle is repeated once again.
LIST OF REFERENCE SYMBOLS
[0000]
1 internal combustion engine
2 Fuel tank
3 Injection system
4 Pressure sensor
5 Temperature sensor
6 Processing unit/device
7 Hydraulic line
10 . . . 18 Boxes in the flowchart
m Gas amount (mass)
p Gas pressure
p d Vapor pressure
T Gas temperature (in the fuel tank)
t Time axis
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In a process and device for determining the composition of a gas mixture of the fuel tank of a motor vehicle filled with a CNG gas, the measured values of a pressure sensor and a temperature sensor, which are generally present in conventional fueled motor vehicles, are used to determine the vapor pressure (pd) of at least one of the gases in the gas mixture, in particular ethane, propane and/or butane. If the vapor pressure of one of the components of the CNG gas in the fuel tank falls short, then one relevant, current composition of the gas mixture is determined. This offers the advantage in an internal combustion engine that as much gas can always be injected with the 20 requisite energy value, as is called for by the specified air-fuel ratio (λ-value) and the conditions of operation. This achieves optimum combustion with minimal exhaust.
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STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalities thereon or therefor.
BACKGROUND OF THE INVENTION
The present invention relates generally to multiple order gradiometers and more particularly, to such gradiometers which have heavy, bulky and costly components associated therewith.
Magnetic fields are commonly measured using either a magnetometer or a gradiometer. A magnetometer is an instrument which measures magnetic field intensity in direct proportion to the sensitivity of a single sensing element and therefore, provides no magnetic field background or noise rejection. Various types of magnetometers are known, such as those which utilize moving and stationary coils, Hall Effect Devices, thin films, fluxgates, magnetic resonance devices, superconducting devices and as disclosed in U.S. Pat. No. 4,433,291, a magnetostrictive segment on an optical fiber element. A gradiometer is an instrument which measures the difference between the magnetic field intensities at two separate locations, with at least one pair of magnetometers. Therefore gradiometers provide common made background or noise rejection which can be enhanced by increasing the number of magnetometer pairs to increase the order of the gradiometer.
Although multiple order gradiometers which utilize various types of magnetometers are known in the art, where extreme sensitivity is required superconducting quantum interference devices (SQUIDs) are commonly utilized therein. Because such gradiometers must be cooled to cryogenic temperatures, such as with liquid helium, the applications therefor are severely limited due to the greater size, weight and expense thereof. Furthermore, where applications do exist for such gradiometers, difficulties are encountered therewith in regard to balancing and trimming, which is usually only accomplished by successive approximations. Magnetostrictive segments on optical fiber elements have been utilized in first order gradiometers to overcome the problems encountered with SQUIDs, as disclosed in my U.S. Pat. No. 4,644,273.
SUMMARY OF THE INVENTION
It is the general object of the present invention to decrease the size, weight and expense of multiple order gradiometers, while facilitating the balancing and trimming thereof.
In accordance with the above stated general object, it is a specific object of the present invention to provide multiple order gradiometers which operate at ambient temperatures.
Another specific object in accordance with the above stated general object, is to structurally consolidate a plurality of magnetometers within multiple order gradiometers.
These and other objects are accomplished in accordance with the present invention by utilizing at least one magnetostrictive segment on optical fiber elements for each magnetometer required in a multiple order gradiometer. Structural consolidation of such magnetometers is accomplished by integrating a plurality of magnetostrictive segments on the same optical fiber elements.
The scope of the present invention is only limited by the appended claims for which support is predicated on the preferred embodiments hereinafter set forth in the following description and the attached drawings wherein like reference characters refer to like parts throughout the several figures.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates one preferred embodiment of the present invention wherein magnetostrictive optical fiber elements serving as magnetometers, are arranged to provide a second order gradiometer;
FIG. 2(a) is an electrically unconnected bar schematic of the magnetometers in the FIG. 1 gradiometer;
FIG. 2(b) is a bar schematic for another second order gradiometer which illustrates how pluralities of magnetometers therein can be consolidated on optical fiber elements relative to the FIG. 2(a) bar schematic;
FIG. 3 illustrates a second order gradiometer with the consolidated arrangement of magnetometers from FIG. 2(b) incorporated therein;
FIG. 4(a) is an electrically unconnected bar schematic of the magnetometers in a third order gradiometer for still another preferred embodiment of the invention;
FIG. 4(b) is a bar schematic for another third order gradiometer which illustrates how pluralities of magnetometers therein can be consolidated on optical fiber elements relative to the FIG. 4(a) bar schematic;
FIG. 4(c) is a bar schematic for still another third order gradiometer which illustrates how pluralities of magnetometers therein can be consolidated further on optical fiber elements; and
FIG. 5 illustrates a third order gradiometer with the consolidated arrangement of magnetometers from FIG. 4(c) incorporated therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One preferred embodiment of the invention is illustrated in FIG. 1 wherein a multiple or higher order gradiometer 10 is shown to have a plurality of magnetometers 12 arranged in pairs 14 to detect a second order gradient. Each magnetometer 12 is a magnetostrictive segment on an optical fiber element and is longitudinally disposed across an axis 16 passing through a magnetic field H, adjacent to at least one other magnetometer 12. Optical fiber elements having a single magnetostrictive segment disposed thereon are well known, as discussed extensively in my U.S. Pat. No. 4,644,273. Such elements need only include magnetostrictive material which is arranged to induce strain in the optical fiber of a magnitude that varies in accordance with, the intensity of the magnetic field H.
Each magnetometer pair 14 in FIG. 1 is conventionally arranged and connected to measure the field inftensity H at a location along the axis 16 with the well known quadrature phasing technique that is utilized in Mach-Zehnder and other types of interferometers. A single frequency laser source 18 directs light through a primary splitter 20 to secondary splitters 22, each of which distributes light beams of equal intensity to each magnetometer 12 in one of the magnetometer pairs 14. Separate beams of light depart from the magnetometers 12 in each magnetometer pair 14 and pass through a combiner 24 which passes those beams on to a field appraisal means 25 for maintaining quadrature and measuring the difference between the field intensities H which are sensed by the magnetometers 12. An initial differencing circuit 26 is disposed in each means 25 and of course, includes a means (not shown) for translating each light beam into an electrical signal, such as a photodiode. Of course, any conventional means can be utilized to provide the differencing function, such as an operational amplifier arranged to subtract the signal outputs from the photodiodes. A conventionally known control means is also included in each differencing circuit 26 for feeding back a phase modulating signal to a stretcher 28 which maintains the quadrature relationship between the light beams which pass through each combiner 24. Because of this quadrature relationship, each field appraisal means 25 produces an output which passes from the differencing circuit 26 and is equivalent to the first order gradient of the magnetic field H. These outputs from the field appraisal means 25 are directed to a means 30 for progressively measuring the difference between pairs of such outputs until a final output 32 is attained having the desired gradient order magnitude. As is well known by those skilled in the art of gradiometers, the number of field appraisal means 25 doubles for each numeric increase in the gradient order magnitude and therefore, the multiple order gradiometer 10 of FIG. 1 measures the magnetic field H as a second order gradientd. It should also be appreciated by those skilled in the art that in higher order gradiometers which are arranged in the manner illustrated by FIG. 1, the difference measuring means 30 will be a ladder structure of differencing circuits which progressively decrease in number by fifty percent at each ladder step until the final output 32 is derived from one last differencing circuit.
Due to the very compact nature thereof, many more magnetostrictive optical fiber elements than are shown in FIG. 1 can be arranged in a reasonably compact multiple order gradiometer 10 of the invention. Also, the substantially perpendicular orientation of the axis 16 relative to the magnetic field H in FIG. 1 is not a limitation and the desired orientation thereof may be made to suit the application of the multiple order gradiometer 10. Furthermore, even though the magnetometers 12 are shown to be adjacently disposed longitudinally across the axis 16 in FIG. 1, for many applications it would be preferable to adjacently dispose the magnetometers 12 longitudinally in tandem, collinearly in the direction of the magnetic field H.
A bar schematic representing the physical arrangement of the magnetometers 12 and the effective polarity thereof in the multiple order gradiometer 10 of FIG. 1, is illustrated by FIG. 2(a). Of course, the magnetometers 12 are adjacently disposed, longitudinally across the axis 16 and in each magnetometer pair 14, one magnetometer 12 makes a positive contribution (arrowhead facing left) to the final output 32 of the multiple order gradiometer 10 and the other magnetometer 12 makes a negative contribution (arrowhead facing right) thereto. However, the effective polarity of the contribution to the final output 32 by the comparably positioned magnetometers 12 in the magnetometer pairs 14 is reversed, because the final output 32 is the result of a second order differential.
The construction generally of multiple order gradiometers 10 can be greatly simplified to further reduce the size, weight and cost thereof, by arranging those magnetometers 12 therein which have the same effective polarity in at least two magnetometer pairs 14 on the same optical fiber elements. For the multiple order gradiometer 10 of FIG. 1, the magnetometers 12 having the same effective polarity in the two magnetometer pairs 14 illustrated by the bar schematic of FIG. 2(a), are so arranged in the bar schematic of FIG. 2(b). The distance separating the magnetometers 12 on each optical fiber element may vary depending on the baseline separation between the magnetometers 12 in the multiple order gradiometer 10. For each optical fiber element in the bar schematic of FIG. 2(b), a summation process inherently occurs therein relative to the contributions made by the plurality of magnetometers 12 disposed thereon. This summation process allows for the multiple order gradiometer 10 of FIG. 1 to be greatly simplified, as shown in FIG. 3 by eliminating the primary splitter 20 and the difference measuring means 30. Furthermore, it should be understood from a comparison of FIGS. 1 and 3 that the number of secondary splitters 22, combiners 24, initial differencing circuits 26 and stretchers 28 in the multiple order gradiometer 10 is decreased by one for each additional magnetometer 12 which is disposed on the optical fiber elements.
Of course, the number of magnetometers 12 required in any multiple order gradiometer 10 is dependent on the gradient order magnitude to be attained thereby. Although theoretical considerations strongly support the conclusion that the number of magnetometers 12 in any multiple order gradiometer 10 may be reduced in number, for the present state of the art this number doubles for each numeric increase in the gradient order magnitude. Consequently, a second order gradiometer includes four magnetometers 12, as shown in FIGS. 1, 2(a and b) and 3, while a third ordder gradiometer includes eight magnetometers 12, as shown in FIGS. 4(a, b and c) and 5. The eight magnetometers 12 in the third order gradiometer may each be disposed on an individual optical fiber element, as shown in the bar schematic of FIG. 4(a), where the magnetometers 12 are arranged in magnetometer pairs 14 to provide a direct analogy with the magnetometers 12 in the bar schematic of FIG. 2(a). Consequently, as was the case in regard to the second order gradiometer of FIG. 1 to which FIG. 2(a) relates, light departing from the magnetometers 12 in each magnetometer pair 14 of the bar schematic in FIG. 4(a) will pass through a combiner 24 to a field appraisal means 25. Of course, an initial differencing circuit 26, and stretcher 28 is combined in each field appraisal means 25. Also, a more complex primary splitter 20 will be required for directing the light from the source 18 to the increased number of secondary splitters 22. Furthermore, the difference measuring means 30 will be a two step ladder structure having two differencing circuits in the first step and one differencing circuit in the second step, with the final output 32 being derived from the latter.
As was explained previously in regard to FIG. 2(b), the construction of multiple order gradiometers 10 is greatly simplified to further reduce the size, weight and cost thereof, by arranging those magnetometers 12 of the same effective polarity in at least two magnetometer pairs 14 on the same optical fiber elements. Of course, the construction of the multiple order gradiometer 10 to which the bar schematic of FIG. 4(a) relates would be somewhat simplified by so arranging the magnetometers 12 in only two magnetometer pairs 14. In such an arrangement, the number of splitters 22, combiners 24, initial differencing circuit 26 and stretcher 28 combinations, as well as the differencing circuits at each step in the ladder structure of the difference measuring means 30 is reduced by one. This simplification is analogous to that accomplished for the multiple order gradiometer 10 of FIG. 1 by consolidating the arrangement of optical fiber elements in FIG. 2(a) as shown in FIG. 2(b), to derive the multiple order gradiometer 10 of FIG. 3.
Other more practical approaches to simplifying the construction of multiple order gradiometers 10 are possible, such as to consolidate the FIG. 4(a) arrangement of optical fiber elements in the manner illustrated by the FIG. 4(b) arrangement, wherein each such optical fiber element has a plurality of magnetometers 12 disposed thereon. In FIG. 4(b) each optical fiber element includes two magnetometers 12, having outputs of the same effective polarity which are to be summed. It should be noted by comparison that in FIG. 4(a) two optical fiber elements are required for each magnetometer pair 14 whereas in FIG. 4(b) only two optical fiber elements are required for each two magnetometer pairs 14. Consequently, the total number of optical fiber elements in the FIG. 4(b) arrangement is equal to half the total number of magnetometers 12 in the multiple order gradiometer 10 to which that arrangement relates, and this is also true in regard to the FIG. 2(b) arrangement. Furthermore, only half the number of splitters 22, combiners 24, initial differencing circuit 26 and stretcher 28 combinations, as well as steps in the ladder structure of the difference measuring means 30, are required for the multiple order gradiometer 10 having the FIG. 4(b) arrangement, as are required for the multiple order gradiometer 10 having the FIG. 4(a) arrangement. This is so because each pair of optical fiber elements in FIG. 4(b) includes magnetometers 12 from two magnetometer pairs 14 of the FIG. 4(a) arrangement.
As shown in FIG. 4(c), the arrangement of optical fiber elements in a third order gradiometer can be consolidated still further than is illustrated in FIG. 4(b), by disposing all the magnetometers 12 on a single pair of optical fiber elements. In the FIG. 4(c) arrangement, all of the magnetometers 12 of each effective polarity are disposed on a single optical fiber, so that one half of the magnetometers 12 in the multiple order gradiometer 10 are disposed on one optical fiber element, while the other half of the magnetometers 12 are disposed on another optical fiber element. Because this arrangement includes only one pair of optical fiber elements, only one splitter 22, combiner 24, initial differencing circuit 26 and stretcher 28 combination is required therefor in the multiple order gradiometer 10, as shown in FIG. 5 for the third order gradiometer to which the FIG. 4(c) arrangement applies. Furthermore, no difference measuring means 30 is required therein.
Those skilled in the art will appreciate without any further explanation that many modifications and variations are possible to the above disclosed multiple order gradiometer embodiments within the concept of this invention. Consequently, it should be understood that all such modifications and variations fall within the scope of the following claims.
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Magnetometers disposed as magnetostrictive segments on optical fiber elems are incorporated in multiple order gradiometers to reduce the size, weight and cost thereof. In the preferred embodiments, such reductions are greatly enhanced by consolidating a plurality of magnetometers on individual optical fiber elements, which also serves to decrease the number of devices associated with the magnetometers in the multiple order gradiometers.
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RELATED APPLICATION DATA
[0001] This application claims the benefit of and priority under 35 U.S.C. §119(e) to U.S. Patent Application Serial No. 60/401,034, filed Aug. 6, 2002, entitled “The Bear Claw,” which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to barrier devices. In particular, this invention relates to a portable, modular, vehicle barrier.
[0004] 2. Description of Related Art
[0005] Vehicle barriers come in a plurality of different sizes, shapes and materials. For example, the “Jersey Wall” is one of the most common and widely used barrier devices. Typically Jersey Walls are made of preformed concrete and are moved with a forklift or dedicated Jersey Wall mover.
[0006] An alternative type of barrier are those seen around military installations and heavily guarded facilities where a hydraulically operated steal plate is embedded in the roadway. To block incoming traffic, the steal plate is raised in a ramp-like configuration to a height suitable for stopping traffic. These types of devices are permanent in nature and are usually installed in a concrete road surface and have an associated control and power facility.
SUMMARY OF THE INVENTION
[0007] While existing systems tend to provide a certain level of protection, they are not always portable, scalability can be difficult to achieve and they tend to be more of a permanent type barrier.
[0008] An exemplary embodiment of the invention is directed toward a barrier, such as a vehicle barrier. The barrier can be used in, for example, high risk traffic stops, as a barrier around or partially around a protected facility, as a barricade for forward stationed basis, or, for example, by a security team around compounds, facilities and/or homes.
[0009] The exemplary barrier, due to its configuration, not only provides incredible vehicle stopping power but also disables vehicles that breach the barrier by, for example, causing significant damage to the undercarriage, motor components and tires.
[0010] Aspects of the present invention relate to a barrier. In particular, aspects of the invention relate to a vehicle barrier.
[0011] Aspects of the invention further relate to a modular vehicle barrier that is disassembleable.
[0012] Aspects of the invention further relate to a vehicle barrier whose components are scalable.
[0013] Furthermore, aspects of the present invention relate to a vehicle barrier that engages with a surface to facilitate stopping of an oncoming vehicle.
[0014] Additional aspects of the invention also relate to a barrier device adapted to support additional security features such as, for example, barbed wire, constantina wire, spikes, or the like.
[0015] These and other features and advantages of this invention are described in, or apparent from, the following detailed description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The embodiments of the invention will be described in detailed, with reference to the following figures, wherein:
[0017] [0017]FIG. 1 is a environmental view of an exemplary barrier according to this invention;
[0018] [0018]FIG. 2 is a side view of a first exemplary embodiment of a plate according to this invention;
[0019] [0019]FIG. 3 is a side view of a second exemplary embodiment of a plate according to this invention;
[0020] [0020]FIG. 4 is a side view of a third exemplary embodiment of a plate according to this invention;
[0021] [0021]FIG. 5 is a side view of a plate according to this invention;
[0022] [0022]FIG. 6 is a perspective view of an exemplary interconnected barrier system according to this invention;
[0023] [0023]FIG. 7 is a perspective view of a second exemplary embodiment of a barrier system according to this invention;
[0024] [0024]FIG. 8 is a partial cross-sectional view of a plate according to this invention;
[0025] [0025]FIG. 9 is a partial cross-sectional view of a plate according to this invention; and;
[0026] [0026]FIG. 10 is a partial cross-sectional view of a plate according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The exemplary systems of this invention will be described in relation to a barrier. However, to avoid unnecessarily obscuring the present invention, the following description omits well-known structures and devices that may be shown in a summarized form. For the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It should be however appreciated that the present invention may be practiced in a variety of ways beyond the specific details set forth herein.
[0028] For example, while the present invention will be described in relation to a barrier having, in general, a hat-shaped structure, it is to be appreciated that the barrier can be combined with one or more other barriers using an interlocking mechanism as discussed herein to further expand the protection afforded by the unit. Furthermore, it should be appreciated that while the exemplary embodiment is illustrated as having substantially flat plates, other sizes, shapes and combinations of shaped plates could also be used without affecting the operability of the system. Additionally, while the panels are preferable constructed of a steal, such as AR500 or Birnell steal, it should be appreciated that other types of steals, compositions, composites, and combinations of materials can be used. For example, the plates could be a multi-layered material that could include carbon fiber, Kevlar® or the like.
[0029] [0029]FIG. 1 illustrates an exemplary embodiment of the barrier 1 . The barrier 1 comprises a plurality of plates 100 interconnected by interconnecting member 5 . As can be seen in FIG. 1, and in accordance with this exemplary embodiment, the plates 100 have a witch-hat shaped design that, when combined with one or more other plates 100 provides a self-standing barrier 1 .
[0030] Thus, in operation, when the barrier 1 is approached by a vehicle generally in direction “A” the barrier is capable of stopping or substantially reducing the speed of the oncoming vehicle by pivoting on the corners opposite the side on which the vehicle engages the barrier.
[0031] While the exemplary barrier 1 illustrated in FIG. 1 comprises nine plates 100 and two interconnecting members 5 , it should be appreciated that any number of plates and interconnecting members can be used without effecting the operation of the invention. For example, to facilitate portability, the barrier 1 could be provided as a kit comprising four plates 100 and two interconnecting members 5 .
[0032] [0032]FIG. 2 is a side view of a exemplary plate 100 according to this invention. In particular, the plate 100 comprises a top portion 10 , feet 20 and 30 , sidewalls 40 and 50 and interconnecting members 5 . In accordance with this exemplary embodiment, the plate 100 has an witch-hat shaped configuration where the top portion 10 is substantially parallel to the base comprising the feet 20 and 30 . Similarly, the sidewalls 40 and 50 are provided at an orientation that the distance there between is greater where they intersect the feet than where they intersect the top portion 10 . While this configuration facilitates uprighting of the plate 100 upon contact by a vehicle, it should be appreciated that the exact dimensions and configuration can be varied in size and shape and the feet adjusted without affecting the operation of the invention. For example, the size and shape of the feet 20 can be varied based on the material the barrier is to be placed on. Specifically, and for example, in an asphalt type environment, it may be advantageous to have the feet 20 and 30 in a pointed type configuration. Alternatively, in a sandy environment, it may be advantageous to have the feet 20 and 30 in a flattened or partially-flattened configuration to aid in supporting the barrier 1 on top of the sand. Likewise, it may be advantageous to have foot 20 in a pointed configuration and foot 30 in flattened configuration or any other combination of feet structures as appropriate for the given conditions.
[0033] In accordance with this exemplary embodiment, the plate 100 is attached to adjacent plates via two interconnecting members 5 that are, for example, round and pipe-shaped that interconnect the plurality of plates 100 .
[0034] [0034]FIG. 3 is a side view of the second exemplary embodiment of a plate 200 . The plate 200 comprises a rounded top portion 210 , feet 200 and 230 , and interconnecting members 25 . In this particular exemplary embodiment, the interconnecting members 25 are bar-shaped and can be, for example, tubular or a solid member constructed out of any type of material. The rounded top portion 210 provides a less aggressive top portion that, while still maintaining the functionality of the barrier 1 , may be more appropriate around highly populated areas or areas where a large number of personnel may be in close proximity to the barrier 1 .
[0035] [0035]FIG. 4 illustrates a third exemplary plate 300 . The exemplary plate 300 comprises a top spiked portion 310 , feet 320 and 330 , and interconnecting members 35 and 45 . In accordance with this exemplary embodiment, the top portion 310 has two or more spike-shaped protrusions that provide a more aggressive barrier 1 and can, for example, provide additional stopping power as the barrier is rotated onto the top portion upon contact by a vehicle. Furthermore, the exemplary plate 300 is interconnected to adjacent plates by a bar 35 and/or T-shaped interconnecting member 45 . Additionally, the feet 320 and 330 are configured such that the plate 300 substantially has an inverted T-shaped configuration.
[0036] While the exemplary embodiments of the plates 100 , 200 and 300 in FIGS. 2, 3 and 4 show various combinations of feet, interconnecting members and top portions, it should be appreciated that these various features can be swapped and interchanged in any combination as appropriate. Also, the top portions and feet can also be different shapes such as semi-hexagonal, semi-octagonal, jagged, or the like. Furthermore, it should be appreciated that the interconnecting members can be in any number, size, shape or configuration, fixed or removable, provided they are capable of supporting a plurality of plates 100 in a substantially upright configuration.
[0037] In addition, it should be appreciated that the plates 100 , 200 and 300 can be fitted with, for example, reflective tape to facilitate visibility, painted in any color, provided with a facade to help facilitate, for example, blending into a particular environment, or provided with supports to carry additional barrier devices that are commonly seen around compounds, facilities and homes such as barbed wire, razor wire, electric fence, signs, a continuous or pseudo-continuous board above the top portion and substantially parallel to the uppermost interconnecting member, or the like.
[0038] [0038]FIG. 5 illustrates a side view of an exemplary embodiment of the plate 100 in an overturned position after, for example, contact by a vehicle. Thus, in operation, as a vehicle approaches from direction “A” as illustrated in FIG. 1, and comes into contact with the barrier 1 , the barrier 1 overturns with foot 30 acting as a fulcrum forcing foot 20 into the undercarriage of the vehicle with the top portion 10 engaging the ground surface 3 to facilitate stopping of the vehicle. Given the symmetric nature of the plate 100 , regardless of the direction of impact, the barrier 1 is capable providing the same type of stopping and undercarriage damaging characteristics. In addition to foot 20 causing undercarriage damage to the vehicle, the foot 20 is also capable of lifting the vehicle that struck the barrier 1 off the ground to further facilitate stopping.
[0039] [0039]FIG. 6 illustrates a perspective view of an exemplary configuration of a plurality of interconnected barriers 1 . In particular, the barriers 1 are set up in a substantially parallel but offset pattern and interconnected by fastener 25 . Using this toe-to-toe configuration, the plurality of barriers can be established in a stair-shaped pattern, a zig-zag pattern, or any other pattern as appropriate. For example, while in the exemplary embodiment in FIG. 6 the two barriers 1 are connected by fastener 25 , it should be appreciated that the barriers need not be interconnected by fasteners but could also be placed end-to-end or substantially end-to-end as appropriate.
[0040] Specifically, FIG. 7 illustrates an exemplary embodiment where two barriers 1 are interconnected end-to-end with fasteners 75 . The fasteners 75 , as with the fastener 25 , can be any known or later developed fastener such as a nut and bolt, pin and cotter key, or any other known or later developed fastener. Likewise, while the illustrated embodiments in FIGS. 6 and 7 show the particular orientations of the barrier sections in relation to one another, it should be appreciated that the barriers can be arranged in any configuration and interconnected in any matter as appropriate.
[0041] [0041]FIG. 8 is a partial cross-sectional view of plate 100 . In this exemplary embodiment, the interconnecting members 5 pass through the plate 100 and the plate 100 is secured between two fasteners 15 . In accordance with this exemplary embodiment, the fasteners 15 are keys however it should be appreciated that any type of fastener can be used in conjunction with the barrier systems and plates discussed herein. Furthermore, while the exemplary embodiment illustrated in FIG. 8 shows the interconnecting members 5 being removable from and slideable through the plate 100 , it should be appreciated that the interconnecting members 5 could also be securely fastened to the plate 100 for example, by welding, or the like. In addition, it should be appreciated that the interconnecting members 5 could extend beyond an end plate and be adapted to beinterconnect with an adjoining barrier. For example, the interconnecting members could have a male-female relationship where adjoining interconnecting members of the barriers would slide together thereby providing a substantially uniform interconnecting member between the plurality of barriers. In addition, it should be appreciated that the spacing between the plates 100 can be varied for example, by placing a plurality of holes 17 in the interconnecting member 5 as illustrated in FIG. 10. This could provide, for example, additional rigidity by allowing an increased number of plates in the barrier 1 which may be appropriate for a particular application.
[0042] [0042]FIG. 9 is a partial cross sectional view of a plate 100 in accordance with another exemplary embodiment of this invention. In particular, in this embodiment, the interconnecting member 5 comprises a threaded male portion 21 and a threaded female portion 23 . The interconnecting member 5 has a greater diameter than the threaded male portion 21 and the threaded female portion 23 thereby securing the plate 100 there between.
[0043] It is, therefore, apparent that there has been provided, in accordance with the present invention, a barrier system. While this invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications, variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, the disclosure is intended to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of this invention.
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A portable and scaleable barrier uses a unique combination of feet, interconnecting members and top portions to provide a vehicle barrier that is capable of, for example, lifting the vehicle of the ground and providing substantial undercarriage damage. The interconnecting nature of the barrier allows the barrier to be configured or adapted based on, for example, a particular environmental condition or application.
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REFERENCE TO RELATED APPLICATION
The present application is a Divisional application of U.S. application Ser. No. 12/489,760, filed Jun. 23, 2009, which status is allowed as U.S. Pat. No. 8,062,632, and claims priority to U.S. Provisional Application No. 61/074,673, filed Jun. 23, 2008, all of which are herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to hepatocytes, and more specifically to method of making hepatocytes from extrahepatic somatic stem cells.
BACKGROUND OF THE INVENTION
The liver is an extraordinary organ capable of modulating its mass according to functional requirements, proliferating under conditions of functional deficiency, and undergoing apoptosis under functional excess [1]. Upon surgical removal of two-thirds of tissue compensatory growth of the remaining portion is observed in the liver to restore the resected mass, although without anatomical reconstitution [2]. While stem or progenitor cells present in postnatal tissue may contribute to the regeneration of liver, the process takes place without the dependence of such cells. Serial repeated partial hepatectomies performed on rodent liver demonstrated restoration of resected tissue mass in the absence of apparent oval cell proliferation [3]. Further, transplantation of a small number of hepatocytes into urokinase-type plasminogen activator transgenic mice resulted in complete repopulation of the liver [4]. These findings demonstrate that hepatocytes possess proliferative potentials under in vivo environments.
Many patients suffer from liver dysfunctions and diseases and, in the shortage of organ donors, there is an increasing clinical demand for hepatocytes for transplantation-based therapy. Although hepatocytes have been shown to exhibit great replicative capacity in vivo, it has been difficult to obtain primary cultures of hepatocytes that both proliferate and maintain liver-specific functions in vitro [5, 6]. Long-term primary cultures of hepatocytes from various mammalian species have been studied extensively over the past three decades and, while improvements in culture conditions have been made to sustain characteristic hepatic functions, cultured hepatocytes show little replicative capacity in vitro [7-16]. It was not until more recently that Hino et al. and Katsura et al. reported conditions enhancing the in vitro proliferative potential of human hepatocytes while retaining differentiated phenotypes [17, 18]. Nevertheless, it is difficult to obtain large numbers of human hepatocytes for clinical applications.
Somatic stem cells, such as mesenchymal stem cells, are multipotent stem cells capable of differentiating into various lineages of the mesoderm, and are easily accessible from bone marrow, umbilical cord blood, and numerous other postnatal tissues [19-23]. It has been previously demonstrated that somatic stem cells isolated from human bone marrow and umbilical cord blood can differentiate into hepatocyte-like cells with morphology, gene expression, and in vitro functions characteristic of hepatocytes [20, 24, 25]. Albeit the differentiated cells exhibit a number of hepatic characteristics, these cells do not possess and sustain a complete repertoire of the properties of parenchymal liver cells, indicating that the differentiation process is only partial.
A previously unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies, especially in connections with culturing hepatocytes.
SUMMARY OF THE INVENTION
In one aspect, the invention relates to a method for preparing hepatocytes, comprising the steps of: a) culturing extrahepatic somatic stem cells in a medium comprising hepatic growth factor (HGF) to cause the somatic stem cells to differentiate toward hepatocytes; b) culturing cells from a) in a medium comprising HGF and oncostatin M (OSM) to facilitate the process of cell differentiation toward hepatocytes; and then c) culturing cells from b) in a medium comprising OSM to cause the differentiated cells to mature into hepatocytes, thereby producing a cell population that has the morphological features of hepatocytes and at least four of the following characteristics: i) antibody-detectable expression of albumin; ii) Real-time reverse transcriptase-polymerase chain reaction-detectable expression of α-fetoprotein, HNF-1α, HNF-3β, HNF-4, HNF-6, α1-antitrypsin, alkaline phosphatase, tryptophan 2,3-dioxygenase, tyrosine aminotransferase, cytochrome P450 family 2 subfamily E polypeptide 1, glutamine synthetase, and/or low density lipoprotein receptor; iii) evidence of urea secretion; iv) evidence of cytochrome p450 enzyme activity; v) evidence of glycogen storage; and vi) evidence of uptake of low density lipoprotein.
In one embodiment of the invention, the aforementioned step a) comprises culturing extrahepatic somatic stem cells in a medium comprising HGF, fibroblast growth factor-2 (FGF-2) and fibroblast growth factor-4 (FGF-4).
In another embodiment of the invention, the aforementioned step b) comprises culturing cells in a medium comprising OSM, HGF, FGF-2, FGF-4 and a bone morphogenic protein (BMP).
In another embodiment of the invention, the BMP is at least one selected from the group consisting of BMP2, BMP3, BMP4, BMP6, BMP7 and BMP8a.
In another embodiment of the invention, the BMP is replaced with a composition comprising nicotinamide, ascorbic acid, insulin, human transferrin and selenous acid.
Further in another embodiment of the invention, the step c) comprises culturing cells in a medium comprising OSM, HGF, FGF-1, FGF-2, FGF-4, dexamethasone, insulin, human transferrin, selenous acid, nicotinamide and ascorbic acid.
Yet in one embodiment of the invention, the culturing in step a) is for a period of at least about 4 days, the culturing in step b) is for a period of about from one to five days, and the culturing in step c) is for a period of at least about 9 days.
In another aspect, the invention relates to a method for preparing hepatocytes comprising the steps of a) culturing extrahepatic somatic stem cells in a medium comprising HGF, fibroblast growth factor-2 (FGF-2) and fibroblast growth factor-4 (FGF-4); b) culturing cells from a) in a medium comprising OSM, HGF, FGF-2, FGF-4 and a bone morphogenic protein (BMP); and then c) culturing cells from b) in a medium comprising OSM, HGF, FGF-1, FGF-2, FGF-4, dexamethasone, insulin, human transferrin, selenous acid, nicotinamide and ascorbic acid, thereby producing hepatocytes.
Further in another aspect, the invention relates to isolated hepatocytes prepared according to one of the aforementioned methods.
Further in another aspect, the invention relates to a method for promoting and/or restoring liver function in an animal in need thereof comprising the step of administering to the animal an effective amount of the aforementioned hepatocytes.
Yet in another aspect, the invention relates to a method for identifying a compound that affects the expression of a hepatic cell marker comprising the steps of: a) exposing the aforementioned hepatocytes to a test compound; b) detecting the expression level of the hepatic cell marker in the hepatocytes exposed to the test compound; and c) comparing the expression level of the hepatic cell marker in the hepatocytes exposed to the test compound with the expression level of the hepatic cell marker in the hepatocytes not exposed to the test compound to determine whether the test compound affects the expression of the hepatic cell marker.
The hepatic cell marker may be selected form the group consisting of albumin, α-fetoprotein, HNF-1α, HNF-3β, HNF-4, HNF-6, α1-antitrypsin, alkaline phosphatase, tryptophan 2,3-dioxygenase, tyrosine aminotransferase, cytochrome P450 family 2 subfamily E polypeptide 1, glutamine synthetase, low density lipoprotein receptor, urea secretion, glycogen storage, and low density lipoprotein uptake.
In another aspect, the invention relates to a method for identifying a compound that affects the expression of a hepatic cell marker comprising the steps: a) exposing the aforementioned hepatocytes to a test compound; b) detecting the expression level of the hepatic cell marker in the hepatocytes exposed to the test compound; and c) comparing the expression level of the hepatic cell marker in the hepatocytes exposed to the test compound with that in the hepatocytes not exposed to the test compound to determine whether the test compound affects the expression of the hepatic cell marker.
Further in another aspect, the invention relates to a method for identifying a compound that affects liver function comprising the steps: a) exposing the aforementioned hepatocytes to a test compound; b) detecting the level of urea secretion, cytochrome p450 enzyme activity and/or uptake of low density lipoprotein of the hepatocytes exposed to the test compound; and c) comparing the level of urea secretion, cytochrome p450 enzyme activity and/or uptake of low density lipoprotein of the hepatocytes exposed to the test compound with that of the hepatocytes not exposed to the test compound to determine whether the test compound affects a liver function.
These and other aspects will become apparent from the following description of the preferred embodiment taken in conjunction with the following drawings, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure.
The accompanying drawings illustrate one or more embodiments of the invention and, together with the written description, serve to explain the principles of the invention. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows the morphology of hepatocytes differentiated from somatic stem cells cultured under hepatogenic conditions.
FIG. 1B shows the expressions of various liver marker genes in hepatocytes differentiated from somatic stem cells cultured under hepatogenic conditions.
FIG. 1C shows the results of immunostaining for albumin in hepatocytes differentiated from somatic stem cells cultured under hepatogenic conditions.
FIG. 1D shows the results of immunostaining for cytokeratin-18 in hepatocytes differentiated from somatic stem cells cultured under hepatogenic conditions.
FIG. 1E shows the results of assay for low density lipoprotein uptake in hepatocytes differentiated from somatic stem cells cultured under hepatogenic conditions.
FIG. 1F shows the results of the detection of cytochrome P450 enzymatic activity in hepatocytes differentiated from somatic stem cells cultured under hepatogenic conditions in the absence of Phenobarbital.
FIG. 1G shows the results of the detection of cytochrome P450 enzymatic activity in hepatocytes differentiated from somatic stem cells cultured under hepatogenic conditions in the presence of phenobarbital stimulation.
FIG. 2 shows the morphology of bone marrow-derived stem cells cultured under (A) stem cell maintenance conditions, and (B) after treatment with the first hepatogenic medium, (C) after treatment with the second hepatogenic medium, and (D) after treatment with the third hepatogenic medium.
FIGS. 3A-3G shows the expression of liver marker genes in somatic stem cells cultured under maintenance conditions (day 0), and in somatic stem cell-differentiated cells growing under hepatogenic conditions for 1 and 2 weeks.
FIG. 4 shows (A) immunostaining for albumin, (B) low density lipoprotein uptake, (C) the ability td secrete urea, (D) the detection of cytochrome P450 enzymatic activity, (E) the staining results for glycogen storage in hepatocytes differentiated from somatic stem cells cultured in hepatogenic medium for 28 days.
FIG. 5 shows the survivorship of NOD-SCID mice with CCl 4 -induced liver failure after transplantation with either placebo or somatic stein cell-differentiated hepatocytes (SCDH).
FIG. 6A shows the post-mortem liver histology of NOD-SCID mice with CCl 4 -induced liver failure that had been transplanted with placebo (control). Arrows indicate large areas of necrotic tissue; arrowheads denote clusters of viable cells.
FIG. 6B shows the post-mortem liver histology of NOD-SCID mice with CCl 4 -induced liver failure that had been transplanted with somatic stem cell-differentiated hepatocytes cultured under hepatogenic conditions for 28 days.
FIG. 6C shows immunostaining for human albumin in the liver of mice transplanted with somatic stem cell-differentiated hepatocytes cultured under hepatogenic conditions for 28 days, with the arrow indicating a cluster of human albumin-positive cells.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
The terms used in this specification generally have their ordinary meanings in the art, within the context of the invention, and in the specific context where each term is used. Certain terms that are used to describe the invention are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the invention. For convenience, certain terms may be highlighted, for example using italics and/or quotation marks. The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that same thing can be said in more than one way. Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this specification.
Unless otherwise defined, 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 pertains. In the case of conflict, the present document, including definitions will control.
As used herein, “around”, “about” or “approximately” shall generally mean within 20 percent, preferably within 10 percent, and more preferably within 5 percent of a given value or range. Numerical quantities given herein are approximate, meaning that the term “around”, “about” or “approximately” can be inferred if not expressly stated.
As used herein, “somatic stem cell,” shall generally mean multipotent stem cells that can differentiate into a variety of cell types. Cell types that somatic stem cells have been shown to differentiate into in vitro or in vivo include osteoblasts, chondrocytes, myocytes, adipocytes, and beta-pancreatic islets cells. The term somatic stem cells can encompass multipotent cells derived from other non-marrow tissues, such as adult muscle side-population cells or the Wharton's jelly present in the umbilical cord, adipose tissue, as well as in the dental pulp of deciduous baby teeth. Because somatic stem cells yet do not have the capacity to reconstitute an entire organ, the term “multipotent stromal cell” has been proposed as a better replacement.
As used herein, “extrahepatic somatic stem cell” shall generally mean any type of somatic stem cells derived from tissues other than the liver, e.g., muscle-derived stem cells, adipose-derived stem cells, placenta-derived stem cells, umbilical cord/umbilical cord-blood-derived stem cells, menstrual blood-derived stem cells, etc.
As used herein, “ITS+ Premix” is a universal culture supplement which contains insulin, human transferrin, and selenous acid, the three most universally essential components of defined culture media. They stimulate cell proliferation of a variety of cells under serum-reduced conditions.
The full names for abbreviations used herein are as follows: ALPL for alkaline phosphatase, TDO2 for tryptophan 2,3-dioxygenase, TAT for tyrosine aminotransferase, GLUL for glutamine synthetase, LDLR for low density lipoprotein receptor, CYP2E1 for cytochrome P450 family 2 subfamily E polypeptide 1.
EXAMPLES
Without intent to limit the scope of the invention, exemplary instruments, apparatus, methods and their related results according to the embodiments of the present invention are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the invention. Moreover, certain theories are proposed and disclosed herein; however, in no way they, whether they are right or wrong, should limit the scope of the invention so long as the invention is practiced according to the invention without regard for any particular theory or scheme of action.
Example 1
Materials and Methods
Isolation of human somalic stem cells. Human bone marrow was aspirated from the femur of healthy donors during fracture surgery with informed consent. Total mononuclear cells were obtained by negative immuno-depletion of CD3, CD14, CD19, CD38, CD66b, and glycophorin-A positive cells using antibodies (RosetteSep®, StemCell Technologies, Vancouver, BC, Canada), followed by Ficoll-Paque (Amersham-Pharmacia, Piscataway, N.J., USA) density gradient centrifugation (1.077 g/cm 3 ), and plated in tissue culture flasks (Becton Dickinson, Franklin Lakes, N.J., USA) with Iscove's modified Dulbecco's medium (IMDM, Gibco BRL, Grand Island, N.Y., USA) and 10% Fetal Bovine Serum (FBS, Hyclone, Logan, Utah, USA) supplemented with 10 ng/ml epidermal growth factor (EGF; R&D Systems, Minneapolis, Minn., USA), 10 ng/ml fibroblast growth factor-2 (FGF-2; R&D Systems), 100 U penicillin, 1000 U streptomycin, and 2 mM L-glutamine (Gibco BRL). Non-adherent cells were removed by medium changes at 12-18 hours post plating. Adherent cells were cultured and colonies that developed from the culture were transferred into new vessels and culture expanded under the same conditions. Cells that showed proliferative advantage were collected and were regarded as stem cells.
Generation of hepatocytes from extrahepatic somatic stem cells. To generate hepatocytes from extrahepatic somatic stem cells, stem cells were seeded at about 1.7×10 4 cells/cm 2 and treated sequentially with the following media: Day 0-7: L-15 Medium supplemented with 20 ng/ml hepatocyte growth factor (HGF; R&D Systems), 10 ng/ml FGF-2 (R&D Systems), and 10 ng/ml FGF-4 (R&D Systems). Day 8-12: L-15 medium supplemented with 5 ng/ml FGF-2, 5 ng/ml FGF-4, 10 ng/ml HGF, 10 ng/ml oncostatim M (OSM; R&D Systems), 10 mM nicotinamide (Sigma-Aldrich), 1 mM ascorbic acid (Sigma-Aldrich), and 1% (v/v) ITS+ premix supplement (Becton-Dickinson). Day 13-28: L-15 medium supplemented with 1 ng/ml FGF-2, 1 ng/ml FGF-4, 2 ng/ml HGF, 20 ng/ml OSM, 10 mM nicotinamide, 1 mM ascorbic acid, 10 −6 M dexamethasone, and 1% (v/v) ITS+ premix supplement.
Total RNA isolation and reverse transcriptase polymerase chain reaction (RT-PCR). Total RNA was prepared from cells using RNEasy kit (Qiagen, Stanford, Valencia, Calif., USA). The first strand cDNA was synthesized using Advantage RT-for-PCR kit (Clontech, Palo Alto, Calif., USA). cDNA was amplified by PCR using Eppendorf MasterCycler Gradient (Eppendorf, Hamburg, Germany). The PCR profile was an initial cycle of 5 min at 94° C., followed by 36 cycles of 30 sec at 94° C., 30 sec at 60° C., and 40 sec at 72° C., and a final cycle of 5 min at 72° C.
Immunocytochemistry. To investigate the formation of hepatocytes from stem cells, somatic stem cells and hepatocytes differentiated therefrom were assessed for the production of albumin, which is a function specific to hepatocytes. Briefly, cells growing on 4-well-chamber slides (Becton Dickinson) at about 1.0−1.7×10 4 cells/cm 2 were fixed in 4% formaldehyde and permeabilized with 0.1% Triton X-100 (Sigma-Aldrich) for 10 minutes. Samples were washed 3 times with blocking solution (phosphate buffered saline (PBS), 5% normal goat serum) each for 5 minutes and incubated with mouse IgG primary antibody (anti-human albumin, Sigma-Aldrich, 1:50; anti-cytokeratin-18, Sigma-Aldrich, 1:50) for 16-20 hours at 4° C. Samples were washed 3 times in PBS each for 5 minutes and incubated with Cy3-conjugated goat anti-mouse IgG secondary antibody (Sigma-Aldrich, 1:100) for 1 hour at room temperature, then washed 3 times in PBS each for 5 minutes. Staining results were visualized with an epifluorescence microscope and images were taken using a SPOT RT imaging system (Diagnostic Instruments, Sterling Heights, Mich., USA).
Uptake of Low-Density Lipoprotein (LDL). Normal hepatocytes are capable of LDL uptake. The ability to take up LDL is therefore an indicator of stem cell-differentiated hepatocytes. Undifferentiated stem cells and stem cell-differentiated hepatocytes growing on 4-well chamber slides (Becton Dickinson) at about 1.0−1.7×10 4 cells/cm 2 were incubated with fluorochrome-conjugated LDL (DiI-Ac-LDL; Biomedical Technologies, Stoughton, Mass., USA) for 4-8 hours at 37° C., 5% CO 2 , which enables the detection of LDL-uptake by cells with an epifluorescence microscope. Imagine was performed using SPOT RT imaging system.
Pentoxyresorufin-O-dealkylase (PROD) assay. Pentoxyresorufin is dealkylated by cytochrome P450 to resorufin, which emits a red fluorescence signal upon excitation with an epifluorescence microscope. The presence of this activity denotes that stem cells are well differentiated into hepatocytes, which have drug-metabolizing enzymes. The assay was performed as follows: Briefly, undifferentiated somatic stem cells and differentiated hepatocytes growing on 4-well chamber slides (Becton Dickinson) at about 1.0-1.7×10 4 cells/cm 2 were stimulated with 1 mM phenobarbital in culture media for 72 hours and then treated with 10 μM pentoxyresorufin. The cytochrome P450 enzyme activity was examined with an epifluorescence microscope. Imaging was performed using SPOT RT imaging system.
Results
Differentiation of Somatic stem cells into functional hepatocytes. Somatic stem cells treated sequentially with different factors under the aforementioned conditions differentiated into cells that manifested phenotypic characteristics of hepatocytes. FIG. 1A shows hepatocyte-like cells differentiated from somatic stem cells cultured under hepatogenic conditions. These differentiated cells exhibited polygonal morphologies characteristic of hepatocytes. They were further characterized by the expression of a comprehensive panel of liver marker genes such as α-fetoprotein, albumin, hepatocytes nuclear factor-1α (HNF-1α), hepatocytes nuclear factor 3β (HNF-3β), hepatocytes nuclear factor 4 (HNF-4), hepatocytes nuclear factor 6 (HNF-6), α1-antitrypsin, glutamine synthetase, tryptophan 2,3-dioxygenase and tyrosine aminotransferase ( FIG. 1B ). GAPDH serves as house-keeping gene. The expressions of these genes suggest that stem cells have become hepatocytes under the hepatogenic conditions.
To further confirm the hepatic phenotype of stem cell-differentiated hepatocytes, a number of assays were performed to assess the functions of differentiated cells. Somatic stem cell-differentiated hepatocytes were stained positive for albumin ( FIG. 1C ). These somatic stem cell-differentiated hepatocytes were also stained positive for cytokeratin-18, a liver filament protein ( FIG. 1D ). The results of the LDL-uptake as determined by epifluorescence microscopy indicated that the somatic stem cell-differentiated hepatocytes exhibited the ability to take up fluorochrome-conjugated LDL ( FIG. 1E ). These somatic stem cell-differentiated hepatocytes exhibited cytochrome P450 enzyme activity, i.e., the ability to convert pentoxyresorufin into resorufin, as shown under the epifluorescence microscopy ( FIG. 1F ). Resorufin produces a red fluorescence upon excitation. The cytochrome P450 enzyme activity in the somatic stem cell-differentiated hepatocytes could be stimulated by Phenobarbital ( FIG. 1G ). Taken together, these results demonstrate that stem cells cultured under hepatogenic conditions acquire phenotypic and functional characteristics of hepatocytes.
Many patients suffer from metabolic liver diseases such as haemochromatosis, Wilson disease, α 1 -antitrypsin deficiency, glycogen storage disease, hereditary tyrosinaemia type I, chronic hepatitis, liver cirrhosis, and cystic fibrosis, as well as acute liver failures resulting from viral, drug, toxin, or immune-mediated insults. In most cases, liver transplantation is currently the only effective treatment for these patients, but the availability of donor organs for clinical use is very limited. For those suffering from acute liver failures, patients often die before an appropriate organ is available [26]. Fortunately, many of the disorders treated by liver transplantation are diseases caused by hepatocyte dysfunction and are unnecessary to replace the entire organ, and could potentially be overcome by hepatocyte transplantation [27]. For this reason, extensive efforts have been devoted to exploring the use of cell transplantation as an alternative to the entire organ and, although limited, some success has been reported [4, 28, 29].
Although normal hepatocytes may serve as an alternative to organ transplantation, the availability of large quantities of cells for clinical use remains to be a problem, and efforts are ongoing in the search for alternative sources for cell transplantation. In contrast to normal hepatocytes, somatic stem cells are readily accessible from the bone marrow, and have also been shown to be isolatable from trabecular bone, synovial membrane, lipoaspirates and umbilical cord blood [19-23]. The ability of somatic stem cells to be propagated prior to and following hepatic differentiation could potentially overcome the shortage of cells for transplantation and provide functional support for patients suffering from liver failure and thus making it an ideal candidate in the clinical setting. In addition, the ability to differentiate somatic stem cells into mature hepatocytes functionally equivalent to those derived from the liver suggest potential applications in drug screening and pharmacological studies as exemplified by the ability to metabolize pentoxyresorufin into resorufin.
Example 2
Materials and Methods
Generation of hepatocytes from extrahepatic somatic stem cells. Extrahepatic somatic stem cells were first isolated according to the procedures as aforementioned. To generate hepatocytes from the extrahepatic somatic stem cells, stem cells were seeded at about 1.7×10 4 cells/cm 2 and treated sequentially with the followings media: Day 0-9: DMEM/F12 supplemented with 20 ng/ml hepatocyte growth factor (HGF; R&D Systems), 10 ng/ml FGF-2 (R&D Systems), 10 ng/ml FGF-4 (R&D Systems). Day 9-12: DMEM/F12 supplemented with 20 ng/ml oncostatin M (OSM; R&D Systems), 20 ng/ml HGF, 2 ng/ml FGF-2, 2 ng/ml FGF-4, 10 ng/ml bone morphogenetic protein 2 (BMP-2; R&D Systems). Day 12-28: DMEM/F12 supplemented with 20 ng/ml OSM, 1 ng/ml HGF, 0.1 ng/ml FGF-1, 0.1 ng/ml FGF-2, 0.1 ng/ml FGF-4, 10 −6 M dexamethasone (Sigma-Aldrich), 1×ITS+ premix supplement (Becton-Dickinson), 0.61 g/L nicotinamide (Sigma-Aldrich), 200 mM ascorbic acid (Sigma-Aldrich). Media changes were performed at 3-day intervals.
Real-lime reverse transcriptase-polymerase chain reaction. To investigate the formation of hepatocytes from somatic stem cells, expression of numerous marker genes that are characteristic of mature hepatocytes were investigated: albumin (ALB), alkaline phosphatase (ALPL), tryptophan 2,3-dioxygenase (TDO2), tyrosine aminotransferase (TAT), glutamine synthetase (GLUL), low density lipoprotein receptor (LDLR) and cytochrome P450, family 2, subfamily E, polypeptide 1 (CYP2E1). Total RNA was prepared from cells using RNEasy kit (Qiagen, Stanford, Valencia, Calif., USA). First strand cDNA was synthesized using Advantage RT-for-PCR kit (Clontech, Palo Alto, Calif., USA). For detection of genes expression by real-time PCR, the first strand cDNA (300 ng) was diluted in a 10 μl reaction containing 2×PCR MasterMix reagent, 200 nM each of sense and anti-sense primers, 100 nM of Universal ProbeLibrary probe. The reactions were incubated in a LightCycler 480 (Roche) at 95° C. for 10 minutes, 40 cycles of 95° C. for 10 seconds followed by 60° C. for 1 minute, and finally 40° C. for 10 seconds. Primers used for real time PCR detection of liver marker genes are shown in Table 1.
TABLE 1
SEQ ID
SEQ ID
Gene
Forward primer
NO.
Reverse primer
NO.
ALB
aatgttgccaagctgctga
1
cttcccttcatcccgaagtt
2
ALPL
agaaccccaaaggcttcttc
3
cttggcttttccttcatggt
4
TDO2
cgatgacagccttggacttc
5
cggaattgcaaactctgga
6
TAT
ccatgatttccctgtccatt
7
ggatggggcatagccattat
8
GLUL
tctcgcggcctagctttac
9
agtgggaacttgctgaggtg
10
LDLR
ccactcgcccaagtttacc
11
tgcagcctcagcctctgt
12
CYP2E1
caagccattttccacagga
13
caacaaaagaaacaactccatgc
14
GAPDH
agccacatcgctcagacac
15
gcccaatacgaccaaatcc
16
Immunocytochemistry. To investigate the formation of hepatocytes from somatic stem cells, cells were assessed for the production of albumin. Cells growing on 4-well chamber slides (Becton Dickinson) at about 1.0-1.7×10 4 cells/cm 2 were fixed in 4% formaldehyde, and permeabilized with 0.1% Triton X-100 (Sigma-Aldrich) for 10 minutes. Samples were washed 3 times, each for 5 minutes, with blocking solution (phosphate buffered saline (PBS), 5% normal goat serum) and incubated with mouse IgG anti-human albumin antibody (Sigma-Aldrich, 1:50) for 16-20 hours at 4° C. Samples were washed 3 times in PBS, each for 5 minutes, and incubated with Cy3-conjugated goat anti-mouse IgG secondary antibody (Sigma-Aldrich, 1:100) for 1 hour at room temperature, then washed 3 times in PBS, each for 5 minutes. Staining results were visualized with an epifluorescence microscope and imaging was performed with SPOT RT imaging system (Diagnostic Instruments, Sterling Heights, Mich., USA).
Low-density lipoprotein (LDL) uptake. The ability of somatic stem cell-differentiated hepatocytes to take up LDL was examined according to the aforementioned method.
Urea secretion. The ability of somatic stem cell-differentiated hepatocytes to secrete urea was investigated because urea secretion is a function characteristic of normal hepatocytes. Culture media were collected from cultures of undifferentiated stem cells and from stem cell-differentiated hepatocytes. Urea concentrations were determined by the QuantiChrome urea assay kit (BioAssay Systems, Hayward, Calif., USA) and analyzed with a Bio-Rad Model 680 microplate reader (Hercules, Calif., USA).
Pentoxyresorufin-O-dealkylase (PROD) assay. The activity of pentoxyresorufin-O-dealkylase was assayed to investigate the ability of somatic stem cell-differentiated hepatocytes to metabolize drugs according to the procedure as aforementioned.
Periodic acid-Schiff (PAS) for glycogen. The ability to store glycogen is a function characteristic of normal hepatocytes. Thus, glycogen storage in the somatic stem cell-differentiated hepatocytes was examined on undifferentiated somatic stem cells and somatic stem cell-differentiated hepatocytes. Cells growing on 4-well chamber slides (Becton Dickinson) at about 1.0-1.7×10 4 cells/cm 2 were fixed in 4% formaldehyde, permeabilized with 0.1% Triton X-100 for 10 minutes. The cells were then oxidized in 1% periodic acid for 5 minutes, rinsed 3 times in dH 2 O, treated with Schiff's reagent for 15 minutes and rinsed in dH 2 O for 5-10 minutes.
Rescue of fulminant hepatic failure. An animal model of acute liver failure was used to evaluate the capability of stem cell-differentiated hepatocytes to rescue recipient animals from liver failure. To avoid rejection of human cells when transplanted into mice, non-obese diabetic severe combined immunodeficient (NOD-SCID) mice were used. NOD-SCID mice were purchased from Tzu Chi University Laboratory Animal Center (Hualien, Taiwan). All animal experiments were performed with the approval of the Animal Care Committee. To induce fulminant hepatic failure in NOD-SCID mice, carbon tetrachloride (CCl 4 ) was dissolved in mineral oil at 10% concentration and administered to animals by gavage at a dosage of 0.28 ml CCl 4 /kg body weight. This led to submassive necrosis of the liver and resulted in 100% lethality in recipient animals by day-6 after administration of CCl 4 . To test the ability of stem cell-differentiated hepatocytes to rescue recipient animals, transplantation of 4.2×10 7 /kg stem cell-differentiated hepatocytes was performed at 24 hours post administration of CCl 4 under 3% isoflurane inhalation anesthesia. Control animals were transplanted with PBS as placebo.
Histological and immuno-histological analysis. To assess the extent of liver damage induced by the administration of CCl 4 as well as the extent of regeneration after cell transplantation, mice were sacrificed at 4 weeks post administration of CCl 4 and liver tissue were excised from NOD-SCID mice (both placebo and cell-transplant group) for sectioning and staining. Tissues were fixed in 3.7% formaldehyde, dehydrated, embedded in paraffin blocks and sectioned at 3-4 μm. For histology, sections were stained with Hematoxylin and Eosin (Sigma-Aldrich). To further investigate the engraftment and functionality of transplanted cells in the liver of recipient animals, liver sections were assessed for the presence of human albumin produced by the transplanted cells. Sections were blocked with blocking solution and incubated with mouse IgG anti-human albumin antibody (Sigma-Aldrich, 1:50) for 16-20 hours at 4° C. Samples were washed 3 times in PBS, each for 5 minutes, and incubated with Cy3-conjugated goat anti-mouse IgG secondary antibody (Sigma-Aldrich, 1:100) for 1 hour at room temperature, then washed 3 times in PBS, each for 5 minutes. Staining results were visualized with an epifluorescence microscope and imaging was performed with SPOT RT imaging system.
Results
Multipotent somatic stem cells isolated from bone marrow specimens and cultured under stem cell maintenance conditions were fibroblast-like in morphology. ( FIG. 2A ). The somatic stem cells developed a broadened morphology after they were cultured in the first medium ( FIG. 2B ). Subsequent to culturing in the second medium, the cells bodies retracted and exhibited more polygonal morphologies with initial formation of cytoplasmic granules ( FIG. 2C ). Further culturing under the third medium, the cells acquired mature cuboidal morphology of normal hepatocytes, characterized by a large nucleus, few nucleoli and numerous cytoplasmic granules ( FIG. 2D ).
To characterize and assess the differentiation of stem cells cultured under hepatogenic conditions, expression of numerous liver marker genes were examined by real-time PCR. Albumin, alkaline phosphatase, tryptophan 2,3-dioxygenase, tyrosine aminotransferase, glutamine synthetase, low density lipoprotein receptor, and cytochrome P450 family 2 subfamily E polypeptide 1 are all genes representing mature functions characteristic of normal hepatocytes and, thus, the expression of these genes were evaluated. As shown in FIGS. 3A-3G , compared to the somatic stem cells cultured under maintenance conditions, expressions of liver marker genes were significantly induced after culturing in the first medium for 1 week, and are further up-regulated after 2 weeks of induction, suggesting lineage commitment into hepatocytes. Culturing stem cells in the second medium sustained the expression of liver marker genes during the transition from the first medium to the third medium (data not shown). While previous studies in the literature have reported differentiation of mesenchymal stem cells into hepatocyte-like cells, those studies demonstrate the expression of genes representative of early and intermediate stages of liver specification [24, 30]. In contrast, the method and condition to induce hepatogenic differentiation described in the current invention significantly enhances the frequency and effectiveness of hepatic lineage commitment. As shown in FIGS. 3A-G , expression of liver marker genes characteristic of advanced hepatic specification and functions only acquired by mature hepatocytes were induced within 2 weeks of culturing stem cells under the hepatogenic conditions described, suggesting the rapidity and high frequency of differentiation.
The first medium initiates the commitment of somatic stem cells into hepatic endodermal phenotype, and induces expression liver marker genes. Treatment'period for the first medium can range between 4 and 18 days or longer. The second medium is a transition medium which sustains the expression of liver marker genes and primes the cells for phenotypic maturation, and optimizes the expression of liver marker genes. Treatment period for the second medium can range between 1 and 5 days or longer. The third medium causes maturation of the cells into functional hepatocytes, and sustains the expression of liver marker genes representative of advanced stages of hepatic differentiation. Treatment with the third medium can be applied for 9 days or longer. The third medium is also used to maintain the hepatocytes differentiated from stem cells, although, fetal bovine serum can be further supplemented to enhance viability of the differentiated hepatocytes.
To further investigate the function of somatic stem cell-differentiated hepatocytes cultured under hepatogenic conditions, a number of in vitro liver, function assays were used. Stem cells cultured under maintenance conditions were negative for albumin while somatic stem cell-differentiated hepatocytes were stained positive for albumin ( FIG. 4A ). Stem cells cultured under maintenance conditions did not take up fluorochrome-conjugated LDL while somatic stem cell-differentiated hepatocytes were fluorescence positive ( FIG. 4B ). The level of urea was undetectable in the medium when stem cells were cultured under maintenance conditions while somatic stem cell-differentiated hepatocytes showed detectable levels of urea in the medium ( FIG. 4C ). Stem cells cultured under maintenance conditions in the presence of phenobarbital did not exhibit the ability to metabolize pentoxyresorufin while somatic stem cell-differentiated hepatocytes showed the ability to convert pentoxyresorufin into resorufin ( FIG. 4D ), which produces a red fluorescence upon excitation, suggesting the presence of cytochrome P450 enzyme activity. Somatic stem cells cultured under maintenance conditions were not stained for intracellular glycogen while somatic stem cell-differentiated hepatocytes reacted positive to the staining ( FIG. 4E ), suggesting the storage of glycogen in cells. Taken together, these data were consistent with the gene expression results shown in FIGS. 3A-3G . The in vitro assays demonstrate that somatic stem cells cultured under hepatogenic conditions acquired mature functions characteristic of the liver, suggesting lineage commitment into hepatocytes with high efficiency.
To investigate the in vivo function of somatic stem cell-differentiated hepatocytes, a previously reported mouse model [31] of chemically-induced acute liver failure was used. As shown in FIG. 5 , transplantation of placebo in recipient mice failed to rescue mice from acute liver failure. In contrast, of the mice that had received transplantation of somatic stem cell-differentiated hepatocytes cultured in hepatogenic conditions for 28 days, three out of five mice were rescued from the hepatic failure.
The post-mortem histological analysis showed submassive necrosis of the liver in the mice that had received placebo transplantation, which was consistent with the induced lethality of animals in the control group ( FIG. 6A ). In comparison, animals that were rescued by transplantation of somatic stem cell-differentiated hepatocytes showed complete regeneration of the liver architecture ( FIG. 6B ). The results of immunocytochemistry showed that clusters of human albumin-positive cells could be identified in the liver of mice rescued by transplantation of somatic stem cell-differentiated hepatocytes ( FIG. 6C ). These results suggest somatic stem cell-differentiated hepatocytes can engraft the liver to rescue NOD-SCID mice undergoing acute liver failure, and are functionally similar to normal hepatocytes.
Taken together, these results demonstrate that when cultured under the hepatogenic condition described above somatic stem cells rapidly acquire phenotypic and functional characteristics of hepatocytes with extremely high frequency.
The foregoing description of the exemplary embodiments of the invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching.
The embodiments and examples were chosen and described in order to explain the principles of the invention and their practical application so as to enable others skilled in the art to utilize the invention and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein.
Some references, which may include patents, patent applications and various publications, are cited and discussed in the description of this invention. The citation and/or discussion of such references is provided merely to clarify the description of the present invention and is not an admission that any such reference is “prior art” to the invention described herein. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference.
REFERENCES
1 Su A I, Guidotti L G, Pezacki J P, et al. Gene expression during the priming phase of liver regeneration after partial hepatectomy in mice. Proc Natl Acad Sci USA. 2002; 99:11181-11186.
2 Bucher N L. Regeneration of mammalian liver. Int Rev Cytol. 1963; 15:245-300.
3 Simpson G E, Finckh E S. The pattern of regeneration of rat liver after repeated partial hepatectomies. J Pathol Bacteriol. 1963; 86:361-370.
4 Rhim J A, Sandgren E P, Degen J L, et al. Replacement of diseased mouse liver by hepatic cell transplantation. Science. 1994; 263:1149-1152.
5 Ryan C M, Carter E A, Jenkins R L, et al. Isolation and long-term culture of human hepatocytes. Surgery. 1993; 113:48-54.
6 Chen H L, Wu H L, Fon C C, et al. Long-term culture of hepatocytes from human adults. J Biomed Sci. 1998; 5:435-440.
7 Rojkind M, Gatmaitan Z, Mackensen S, et al. Connective tissue biomatrix: its isolation and utilization for long-term cultures of normal rat hepatocytes. J. Cell Biol. 1980; 87:255-263.
8 Clement B, Guguen-Guillouzo C, Campion J P, et al. Long-term co-cultures of adult human hepatocytes with rat liver epithelial cells: modulation of albumin secretion and accumulation of extracellular material. Hepatology. 1984; 4:373-380.
9 Dunn J C, Yarmush M L, Koebe H G, et al. Hepatocyte function and extracellular matrix geometry: long-term culture in a sandwich configuration. FASEB J. 1989; 3:174-177.
10 Lanford R E, Carey K D, Estlack L E, et al. Analysis of plasma protein and lipoprotein synthesis in long-term primary cultures of baboon hepatocytes maintained in serum-free medium. In Vitro Cell Dev Biol. 1989; 25:174-182.
11 Tong J Z, Bernard O, Alvarez F. Long-term culture of rat liver cell spheroids in hormonally defined media. Exp Cell Res. 1990; 189:87-92.
12 Dunn J C, Tompkins R G, Yarmush M L. Lone-term in vitro function of adult hepatocytes in a collagen sandwich configuration. Biotechnol Prog. 1991; 7:237-245.
13 Roberts E A, Letarte M, Squire J, et al. Characterization of human hepatocyte lines derived from normal liver tissue. Hepatology. 1994; 19:1390-1399.
14 Tong J Z, Sarrazin S, Cassio D, et al. Application of spheroid culture to human hepatocytes and maintenance of their differentiation. Biol Cell. 1994; 81:77-81.
15 Berthiaume F, Moehe P V, Toner M, et al. Effect of extracellular matrix topology on cell structure, function, and physiological responsiveness: hepatocytes cultured in a sandwich configuration. FASEB J. 1996; 10:1471-1484.
16 Tateno C, Yoshizato K. Long-term cultivation of adult rat hepatocytes that undergo multiple cell divisions and express normal parenchymal phenotypes. Am J. Pathol. 1996; 148:383-392.
17 Hino H, Tateno C, Sato H, et al. A long-term culture of human hepatocytes which show a high growth potential and express their differentiated phenotypes. Biochem Biophys Res Commun. 1999; 256:184-191.
18 Katsura N, Ikai I, Mitaka T, et al. Long-term culture of primary human hepatocytes with preservation of proliferative capacity and differentiated functions. J Surg Res. 2002; 106:115-123.
19 Pittenger M F, Mackay A M, Beck S C, et al. Multilineage potential of adult human mesenchymal stem cells. Science. 1999; 284:143-147.
20 Lee O K, Kuo T K, Chen W M, et al. Isolation of multipotent mesenchymal stem cells from umbilical cord blood. Blood. 2004; 103:1669-1675.
21 Sottile V, Halleux C, Bassilana F, et al. Stem cell characteristics of human trabecular bone-derived cells. Bone. 2002; 30:699-704.
22 De Bari C, Dell'Accio F, Tylzanowski P, et al. Multipotent mesenchymal stem cells from adult human synovial membrane. Arthritis Rheum. 2001; 44:1928-1942.
23 Zuk P A, Zhu M, Ashjian P, et al. Human adipose tissue is a source of multipotent stem cells. Mol Biol Cell. 2002; 13:4279-4295.
24 Lee K D, Kuo T K, Whang-Peng J, et al. In vitro hepatic differentiation of human mesenchymal stem cells. Hepatology. 2004; 40:1275-1284.
25 Banas A, Yamamoto Y, Teratani T, Ochiya T. Stem cell plasticity: learning from hepatogenic differentiation strategies. Dev Dyn. 2007; 236:3228-3241.
26 Gill R Q, Sterling R K. Acute liver failure. J Clin Gastroenterol. 2001; 33:191-198.
27 Grompe M. Liver repopulation for the treatment of metabolic diseases. J Inherit Metab Dis: 2001; 24:231-244.
28 Grompe M, Lindstedt S, al-Dhalimy M, et al. Pharmacological correction of neonatal lethal hepatic dysfunction in a murine model of hereditary tyrosinaemia type I. Nat. Genet. 1995; 10:453-460.
29 Fox I J, Chowdhury J R, Kaufman S S, et al. Treatment of the Crigler-Najjar syndrome type I with hepatocyte transplantation. N Engl J. Med. 1998; 338:1422-1426.
30 Banas A, Teratani T, Yamamoto Y, Tokuhara M, Takeshita F, Quinn G, Okochi H, Ochiya T. Adipose tissue-derived mesenchymal stem cells as a source of human hepatocytes. Hepatology. 2007; 46:219-228.
31 Kuo T K, Hung S P, Chuang C H, Chen C T, Shill Y R, Fang S C, Yang V W, Lee O K. Stem cell therapy for liver disease parameters governing the success of using bone marrow mesenchymal stem cells. Gastroenterology. 2008; 134:2111-2121.
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A method for preparing isolated hepatocytes is disclosed. The method comprises: a) culturing mesenchymal stem cells (MSCs) in a medium comprising hepatic growth factor (HGF) to cause the MSCs to differentiate toward hepatocytes, wherein the MSCs are isolated from bone marrow or umbilical cord blood; b) culturing cells from a) in a medium comprising HGF and oncostatin M (OSM) to facilitate the cell differentiation toward hepatocytes; and c) culturing cells from b) in a medium comprising OSM to cause the differentiated cells to mature into hepatocytes, and thereby producing the isolated hepatocyte cells.
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FIELD OF THE INVENTION
[0001] The field of the invention is subterranean tools that deploy by swelling and more particularly construction details and techniques that accelerate the swelling rate for faster deployment.
BACKGROUND OF THE INVENTION
[0002] Packers made of an element that swells in oil or water have been in use for some time as evidenced by U.S. Pat. Nos. 7,997,338; 7,562,704; 7,441,596; 7,552,768; 7,681,653; 7,730,940 and 7,597,152. These designs focus on construction techniques for faster deployment, mechanical compression assists to the swelling or enhancing the performance of an inflatable using an internal swelling material to enhance the seal, elimination of leak paths along the mandrel after swelling and running conduits through the swelling sealing element and still having a good seal.
[0003] Shape conforming screens that take the shape of open hole and act as screens have been disclosed using shape memory foam that is taken above its transition temperature so that the shape reverts to an original shape which is bigger than the surrounding open hole. This allows the foam to take the borehole shape and act effectively as a subterranean screen. Some examples of this are U.S. Pat. Nos. 7,013,979; 7,318,481 and 7,644,773. The foam used heat from surrounding wellbore fluids to cross its transition temperature and revert to a shape that let it conform to the borehole shape.
[0004] One problem with swelling materials is that the swelling rate can be very slow and that effective deployment requires the swelling to complete to a particular degree before subsequent tasks can commence at the subterranean location. What is known is that if there is more heat that the swelling to the desired configuration, so that subsequent operations can commence, can happen sooner rather than later. Since time has an associated cost, it has been an object to accelerate the swelling or reverting to a former shape process, depending on the material involved.
[0005] Various techniques have added heat with heaters run in on wireline or embedded in the packer itself and triggered from a surface location, or have used the heat from well fluid at the deployment location, or heat from a reaction to chemicals pumped to the deployment location, or induction heating of shape memory metals. Some examples are: U.S. Publication 2010/0181080; U.S. Pat. No. 7,703,539; U.S. Publication 2008/0264647; U.S. Publication 2009/0151957; U.S. Pat. No. 7,703,539; U.S. Pat. No. 7,152,657; U.S. Publication 2009/0159278; U.S. Pat. No. 4,515,213; U.S. Pat. No. 3,716,101; U.S. Publication 2007/0137826; CN2,078,793 U (steam injection to accelerate swelling); and U.S. Publication 2009/0223678. Other references have isolated reactants and a catalyst in composite tubulars that have not been polymerized so they are soft so that they can be coiled for deployment and upon deployment expansion of the tubular allows the reaction to take place to make the tubular string rigid. This is illustrated in U.S. Pat. No. 7,104,317.
[0006] Bringing together discrete materials downhole for a reaction between them is illustrated in U.S. Pat. No. 5,582,251.
[0007] The present invention seeks to accelerate swelling in packers and screens made of swelling material by a variety of techniques. One way is to embed reactants and, if necessary, a catalyst in the swelling material and allow the reaction to take place at the desired location to speed the swelling to conclusion. This generally involves a removal of a barrier between or among the reactants in a variety of ways to get the exothermic reaction going. Various techniques of barrier removal are described. The heat is given off internally to the swelling member where it can have the most direct effect at a lower installed cost.
[0008] Another heat addition alternative involves addition of metallic, preferably ferromagnetic particles or electrically conductive resins or polymers in the swelling material. Induction heating is used to generate heat at the particles or resin or polymer to again apply the heat within the element while taking up no space that is of any consequence to affect the ability of the packer to seal when swelling or the screen to exclude particles when the screen is against the borehole wall in an open hole, for example. Optionally the mandrel can be dielectric such as a composite material so that the bulk of the heating is the particles alone. Otherwise the mandrel itself can also be heated and transfer heat to the surrounding element. Induction heating of pipe is known for transfer of heat to surrounding cement as discussed in U.S. Pat. No. 6,926,083 but the rate of heat transfer is very much dependent on a temperature gradient from the pipe into the cement and is less effective than inductively heating the object that needs the heat directly as proposed by the present invention. Also relevant is U.S. Pat. No. 6,285,014 which heats casing with an induction heater lowered into the casing with the idea that the heated casing will transfer heat to the surrounding viscous oil and reduce its viscosity so that it can flow.
[0009] Those skilled in the art will better appreciate additional aspects of the invention by a review of the detailed description of the preferred embodiments and the associated drawings while recognizing that the full scope of the invention is to be determined by the appended claims.
SUMMARY OF THE INVENTION
[0010] The swelling rate of a swelling packer element or a conforming foam screen material is accelerated with heat. In one variation reactants that create an exothermic reaction plus a catalyst, if needed, are allowed to come into contact upon placement at the desired location. In another technique metallic, preferably ferromagnetic, particles or electrically conductive resins or polymers are interspersed in the swelling material and heat is generated at the particles by an inductive heater. A dielectric mandrel or base pipe can be used to focus the heating effect on the ferromagnetic particles or the electrically conductive resins or polymers in the sealing element or swelling foam screen element to focus the heating there without heating the base pipe. The heat accelerates the swelling process and cuts the time to when the next operation can commence downhole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic illustration of the embodiment where the reactants are held apart until they are allowed to mix and react to cause a release of heat to accelerate the swelling of the element; and
[0012] FIG. 2 is a schematic illustration of an alternative embodiment using ferromagnetic particles or the electrically conductive resins or polymers in the element and induction heating to accelerate swelling in the element;
[0013] FIG. 3 shows the barrier between reactants broken with a shifting sleeve extending a knife;
[0014] FIG. 4 illustrates the use of a sliding sleeve to move a protective anode out of contact with a barrier and bring a cathode into barrier contact to accelerate barrier degradation and the onset of the exothermic reaction;
[0015] FIG. 5 illustrates the use of a corrodible conductive barrier whose failure is accelerated with inductive heating.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Referring to FIG. 1 , the mandrel 1 supports an element 2 that can be a swelling packer element or a porous screen material that swells. In either case the objective is to speed up the swelling process with the addition of heat so that the next operation at the subterranean location can take place without having to wait a long time for the swelling to have progressed to an acceptable level. FIG. 1 illustrates heat added directly into the element 2 as opposed to indirect ways that depend on thermal gradients for heat transfer such as using the temperature in the surrounding well fluids in the annulus 8 of the wellbore 10 , which is preferably open hole but can also be cased or lined. Compartments 3 and 5 are separated by a barrier 4 . The individual reactants and a catalyst, if needed, are stored in compartments 3 and 5 . At the desired location or even on the way to the desired location the objective is to make the barrier fail or become porous or otherwise get out of the way of separating the reactants in the compartments 3 and 5 so that such reactants with a catalyst, if any, can come together for an exothermic reaction that will enhance the swelling rate of the element 2 .
[0017] Arrow 12 schematically illustrates the variety of ways the barrier 4 can be compromised. One option is a depth actuation where one side of the barrier is sensitive to hydrostatic pressure in the annulus 8 and the other compartment is isolated from hydrostatic pressure in the annulus 8 . Exposure to pressure in annulus 8 to say compartment 3 can be through a flexible membrane or bellows that keeps well fluid separate from a reactant in compartment 3 . At a given depth the annulus pressure communicating through compartment 3 and into the barrier 4 puts a differential pressure on the barrier to cause it to fail allowing compartments 3 and 5 to communicate and the exothermic reaction to start. Another variation on this if the annulus pressure is too low is to pressurize the annulus 8 when it is desired to start the reaction and the rest takes place as explained above when relying on hydrostatic in the annulus 8 .
[0018] Another way is to use a timer connected to a valve actuator that when opened allows well fluid to get to the barrier 4 and either melt, dissolve or otherwise fail the barrier 4 . The power for the timer and the actuator can be a battery located in the element 2 .
[0019] Another way is to rely on the expected temperature of well fluid to permeate the element 2 and cause the barrier 4 to melt or otherwise degrade from heat from the well fluids.
[0020] FIG. 3 illustrates the compartments 3 and 5 separated by the barrier 4 located within the element 2 that is mounted to the mandrel or base pipe 1 . A sleeve 20 has a ball seat 22 that accepts a ball 24 . Pressure from above on the ball shifts the sleeve 20 and force knife 26 to move radially to penetrate the barrier 4 . Note that the knife 26 moves through a wall opening 28 . Alternatively the knife 26 can be induced to move axially to slice through the barrier 4 using a physical force as described above or equivalent physical force or by using an indirect force such as a magnetic field. If the operator finds the use of a wall opening 28 unacceptable in a swelling packer application then the knife can be magnetized and located within compartment 3 and a magnet can be delivered to the location of the element 2 so that the repulsion of the two magnets can advance the knife 26 axially or radially through the barrier 4 . If the element 2 is a porous screen the tubular 1 will be perforated under the element 2 so that an opening 28 for the knife 26 should be of no consequence for the operator.
[0021] Another variation is to use galvanic corrosion using one or more electrodes associated with the barrier 4 . In run in mode an electrode can be energized to prevent the onset of corrosion and ultimate failure of barrier 4 , while in another mode the corrosion can be initiated using the same electrode or another electrode associated with the barrier 4 . The process can be actuated from the surface or in other ways such as by time, pressure or temperature triggers to initiate the corrosion process. Alternatively, the barrier 4 , itself can be the sacrificial member of a galvanic pair and just corrode over time. Alternatively a corrosive material can be stored in a pressurized chamber with a valve controlled by a processor to operate a valve actuator to allow the corrosive material to reach the barrier 4 and degrade the barrier to start the exothermic reaction.
[0022] Another alternative is to use at least one reactant that over time will attack the barrier 4 and undermine it.
[0023] In another variation, one compartment contains a reactant corrosive to the barrier 4 , for example NaCl aqueous solution or seawater. The second compartment contains dry super-corroding Mg alloy powder or sintered powder (see U.S. Pat. No. 4,264,362), or powder or sintered powder prepared by grinding Mg and Fe powder (see U.S. Pat. No. 4,017,414). NaCl or KCl, for example, may be added to the second compartment. The barrier 4 is preferably made of a Mg alloy. Its corrosion rate depends on the temperature. Since the barrier 4 is electrically conductive, its temperature can be increased using the induction heater 32 as shown in FIG. 5 . This will accelerate the barrier corrosion and, thus, will initiate the exothermic reaction between the chemicals in two compartments.
[0024] In another variation, the compartment containing NaCl solution also contains a Mg electrode with a corrosion potential lower than that of the Mg alloy barrier. This Mg electrode is in mechanical and electrical contact with the barrier 4 , so it acts as a sacrificial anode immersed into the same electrolyte and preserves the barrier from corrosion. A dielectric “knife” 26 actuated by a sleeve as described above, separates the sacrificial anode from the Mg alloy barrier and, thus, the barrier corrosion rate increases.
[0025] In another variation, “knife” is composed of anodic and cathodic portions, which are separated by a dielectric. Initially, anodic part of the knife is in electrical and mechanical contact with the corrodible barrier. In this configuration, the barrier is preserved by the sacrificial anode. As the knife moves, cathodic part of the knife starts contacting the barrier while the anodic part is disconnected from the barrier. This will accelerate the corrosion of the barrier since it is now a sacrificial anode, as shown in FIG. 4 .
[0026] In another version, the “knife” is cathodic with respect to the barrier. Initially it does not contact the barrier. Motion of the sleeve places the knife in contact with the barrier and the electrolyte. Now the barrier serves as a sacrificial anode.
[0027] Thus for a swelling material that acts as a packer the compartments 3 and 5 and the barrier 4 between them can be embedded in the element 2 . The same goes for the use of swelling foam that acts as a self-conforming screen with the difference being that the foam is deliberately porous and the mandrel or pipe 1 is perforated.
[0028] Another alternative technique is schematically illustrated in FIG. 2 . Here the swelling material 2 is impregnated or infused or otherwise produced to have a distribution of metal particles and preferably ferromagnetic particles, or particles made of electrically conductive resins or polymers, 30 . The particles can be positioned in swelling foam by forcing the particles through the material 2 during the fabrication process. This can be done with flow through the foam and can be coordinated with compressing the foam to get its profile reduced for run in. An induction heater 32 is preferably run in on wireline 34 for a power source although local power and a slickline can also be used. The heater 32 can be radially articulated once in position so that its coils extend into close proximity of the tubular inside wall. While electromagnetic induction heating can also be used to locally increase the temperature of a ferromagnetic pipe 1 on which a packer or a totally conformable screen 2 is mounted, the preferred method is to use a dielectric mandrel 1 and, thus, to generate heat in the electrically conductive particles 30 distributed within the swelling element 2 directly. If the pipe 1 is metallic, it will increase the temperature of the packer or the screen 2 mounted on it and, thus, will stimulate deployment. Induction heating is the process of heating an electrically conducting object (usually a metal) by electromagnetic induction, where eddy currents are generated within the metal and resistance leads to Joule heating of the metal. In an induction downhole heater 32 , a coil of insulated copper wire is placed inside the production pipe 1 opposing the packer or the conformable screen 2 . An alternating electric current from the power source on the ground level delivered for example through wireline 34 , is made to flow through the coil, which produces an oscillating magnetic field which creates heat in the base pipe in two different ways. Principally, it induces an electric current in the base pipe, which produces resistive heating proportional to the square of the current and to the electrical resistance of the pipe. Secondly, it also creates magnetic hysteresis losses in the base pipe due to its ferromagnetic nature. The first effect dominates as hysteresis losses typically account for less than ten percent of the total heat generated. Induction heaters are faster and more energy-efficient than other electrical heating devices. Moreover, they allow for instant control of heating energy. Since the induction heaters are more efficient when in the close proximity to the base pipe, it is suggested that the copper wire coils are mounted on an expandable, toward the pipe wall, wire line tool activated when it reaches the level of the packer or the screen.
[0029] If the mandrel 1 is dielectric, then the full effect of the heater 32 will go into the ferromagnetic particles 30 that are embedded in the element 2 and locally heat the element 2 from within. Preferably the particles will be randomly distributed throughout the element 2 so that the swelling process can be accelerated. Alternatively the mandrel 1 can be electrically conductive and the heating effect will take place from the mandrel 1 and from the ferromagnetic particles 30 , if the field is not completely shielded by the pipe 1 .
[0030] The ferromagnetic particles 30 are most simply incorporated into the element 2 at the time the element 2 is manufactured. In the case of a foam element 2 the ferromagnetic particles 30 can be in a solution that is pumped through the foam under pressure so as to embed the particles in the foam from a circulating process. The particles can also be incorporated into the manufacturing process for the element 2 rather than being added thereafter. Another more complex alternative is to add the particles to the element 2 after the element is at the desired subterranean location but monitoring the effectiveness of this mode of ferromagnetic particle addition can be an issue.
[0031] As an alternative to the metal or ferromagnetic particles the element 2 can be impregnated with electrically conductive resins or polymers also shown schematically as 30 and with induction heater 32 the result is the same as the heating effect described above using ferromagnetic particles.
[0032] The heater 32 can be moved in a single trip to accelerate swelling at a series of packers or screen sections. In the case of packers pressure can be applied to see if there is leakage or not past the packer after a predetermined time of heat application.
[0033] The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.
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The swelling rate of a swelling packer element or a conforming foam screen material is accelerated with heat. In one variation reactants that create an exothermic reaction plus a catalyst, if needed, are allowed to come into contact upon placement at the desired location. The heat accelerates the swelling process and cuts the time to when the next operation can commence downhole.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a contact lens care system for cleaning and disinfecting contact lenses, and to the method therefor. More particularly, the contact lens care system is a multi-electrode device which utilizes the principles of electrolysis and electrophoresis to both disinfect and clean contact lenses.
2. Description of the Related Art
It is particularly important that so-called soft contact lenses be kept sterile, because they tend to cause infections in the eye if they are not periodically disinfected.
Past methods of disinfecting such lenses have involved such cumbersome steps as boiling them for a predetermined length of time, or immersing them in a disinfecting solution, particularly hydrogen peroxide solutions. The latter method also requires immersing the lenses in a neutralizing or rinsing solution to remove the disinfecting solution from the lenses, because this solution can be highly irritating to the eye.
These methods suffer from various drawbacks, for example the lens disinfection unit may be cumbersome to use, since it may require the insertion and removal of the lens holder several times during the course of the process. Additionally, the user may forget to neutralize the lenses after disinfection, or confuse the disinfecting and rinsing solutions with one another, since both solutions are usually clear solutions. Needless to say, it is extremely dangerous to insert into one's eye a contact lens which has not had the disinfecting solution entirely removed.
Contact lenses must also be cleaned to remove contaminants from the lenses such as proteinaceous substances, and methods for cleaning contact lenses to remove these substances include the immersion of the lenses in surface active agents (i.e. soaps), enzymes, etc. These methods typically require that the cleaning solution be rinsed from the lenses, and the methods typically do not accomplish a satisfactory disinfection of the lenses.
Methods for cleaning contact lenses using an electrophoretic system have been known, such as those described in U.S. Pat. Nos. 4,921,544 and 4,732,185, however these methods have not proved to be completely satisfactory. These methods involve the immersion of the contact lenses in a buffer solution, and the creation of an electric field in the solution by a pair of spaced electrodes. Contaminants on the lenses such as proteins become charged and are attracted to the oppositely charged electrode, thereby cleaning the lenses.
Some drawbacks to these methods are that in order to disinfect the lenses, a disinfecting agent is typically required to be added to the buffer solution. As in the above-described methods, the disinfecting agent must be neutralized or rinsed from the lenses before insertion into the eye. Other drawbacks are, for example, that protein may be accumulated on the electrodes during electrolysis, and that a lengthy disinfection time may be needed.
Methods for disinfecting contact lenses using an electrolytic system have been known, such as proposed in Japanese Patent Publication No. 60-2055, however these methods have not proved entirely satisfactory. These methods involve the creation of a disinfecting solution by the electrolysis of a saline solution to produce chlorine (Cl 2 ). Such methods are ineffective in completely removing proteinaceous materials from the contact lenses so that surface active agents, enzymes, etc. are typically needed to clean the lenses. The lenses must also be rinsed at the completion of that type of disinfecting process before insertion in the eye of the wearer to remove the chlorine.
Other known methods for cleaning contact lenses using the principle of electrolysis include the method proposed in Japanese Patent Publication 63-254416. That method uses a multi-electrode device which cleans contact lenses by the electrolysis of a physiologic saline solution to produce a high pH solution in the well containing the contact lenses. The highly alkaline solution dissolves the proteinaceous substances on the lenses, and an ultrasound cleaning device is used to help remove these substances from the lens surfaces. After cleaning of the lenses, the alkaline solution is then neutralized by reversing the polarity of the electrodes, thereby avoiding the need of rinsing or neutralizing the alkaline solution on the lenses before insertion in the eyes. This method does not disinfect the contact lenses.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved contact lens care system and method for both cleaning and disinfecting contact lenses, which method is simple and easy to use and overcomes the above-described disadvantages of known methods and devices for cleaning and disinfecting contact lenses.
More particularly, it is an object of the invention to provide a contact lens care system which can both clean and disinfect contact lenses, and which can then neutralize the cleaning and disinfecting solution used, so that the lenses may be immediately placed in the eyes of the wearer after cleaning and disinfecting without the need for any rinsing of the lenses.
It is a further object of the invention to provide a contact lens care system and method which can accomplish cleaning and disinfecting of contact lens without the need to digitally clean the lenses (i.e. by hand); without the need to change the solution; without the need to add any additional chemicals to the solution; and without the need to insert and remove the lenses in the device several times during the process.
With the foregoing objects in mind, the contact lens care system of the present invention will be briefly described, after which the contact lens care system will be described in detail hereinbelow with reference to the preferred embodiments of the invention.
The contact lens care system of the present invention is a multi-electrode device comprising a housing having one or two wells which serve as cavities for holding the contact lenses and for immersing the contact lenses in the cleaning and disinfecting solution. Regardless of whether one or two lens wells are provided, each lens well is provided with two opposing electrodes spaced apart from each other for inserting one or two contact lens or lenses therebetween. When one lens well is provided, the opposing electrodes are preferably spaced apart for receiving two contact lenses therebetween, so that two lenses may be cleaned at the same time. The opposing electrodes in such a single well may be spaced apart for receiving and cleaning only a single contact lens, but such system has the disadvantage of only being capable of cleaning a single contact lens at a time. On the other hand, when two lens wells are provided, the opposing electrodes may be spaced apart for receiving a single contact lens therebetween, thereby two contact lenses may be cleaned at the same time using this design.
The contact lens or lenses are placed in the lens well between the opposing electrodes. Preferably, a lens holding means is provided for holding the contact lens or lenses in the well between the electrodes. The surfaces of the opposing faces of the electrodes which face the contact lens may be adapted to serve as the lens holding means, for example by configuring the shape of the opposing faces of the electrodes into complementary convex and concave configurations, adapted to the shape of the curved contact lens. In this case, the opposing electrodes are preferably spaced apart for receiving a single contact lens. Alternatively, the lens holding means may be a lens basket for holding one or two contact lenses in a spaced apart arrangement. In this case, the opposing electrodes are spaced apart for receiving the lens basket therebetween.
In addition to the lens wells, the housing of the device is provided with another cavity for holding the disinfecting and cleaning solution. This cavity or reservoir has at least one electrode.
The lens well or wells are connected to the reservoir by an ion permeable bridge such as a narrow channel, a porous inert divider, an ion permeable membrane, or any other conventional structure which functions as a salt bridge. If two lens wells are provided, the two lens wells may also be connected to each other so that the cleaning and disinfecting solution in the two lens wells may communicate. Alternatively, the lens wells may be isolated from each other so that the cleaning and disinfecting solution may not communicate between the wells except through the reservoir.
If a narrow channel is used as the ion permeable divider, it is desirable that the channel between the lens well or wells and the reservoir be completely filled with the disinfecting and cleaning solution, so that air bubbles in the channel can be minimized, and so that the most effective salt bridge may be established between the lens well or wells and the reservoir. In order to accomplish this object, the present invention utilizes a novel method for filling the lens well or wells and the channel with the disinfecting and cleaning solution.
That is, the reservoir is first filled with the disinfecting and cleaning solution to a predetermined level. A solution displacement block, adapted to fit into an upper portion of the reservoir, is then inserted into the reservoir. The solution displacement block forces a predetermined amount of cleaning and disinfecting solution from the reservoir through the channel into the lens well or wells. The predetermined amount of solution forced into the lens well or wells is sufficient to totally immerse the opposing surfaces of the electrodes and the contact lens inserted therebetween. And, due to the location of the channel opening and the electrode in the reservoir, the level of disinfecting and cleaning solution which remains in the reservoir after insertion of the solution displacement block is sufficient to immerse the channel opening and the reservoir electrode, thereby allowing for electrolytic reactions to occur at the electrode, and thereby allowing for ion communication between the reservoir and the lens well or wells through the channel.
The device of the present invention also includes a control means, operatively connected to the electrodes of the lens well or wells and the reservoir. The control means permits the control of the polarity of each electrode and the amount of potential voltage applied to each electrode. Preferably the control means is automatic and controls the electrode polarity and potential voltage according to a predetermined program. Preferably, the control means also includes a timing means for automatically controlling the length or duration of the polarity and the potential applied to each electrode.
Thus, the lens care system of the present invention is effective in both cleaning and disinfecting contact lenses using the principles of electrolysis and electrophoresis. The following is a summary of the cleaning and disinfecting process.
The disinfecting and cleaning solution used in the lens care system of the present invention may be any halide-containing electrolytic buffer solution. Examples of preferable electrolytic buffer solutions are borate, phosphate or other physiologically compatible buffer saline solutions. Examples of preferable halide compounds are NaCl, KCl, NaBr and KBr.
The contact lens or lenses are placed in the lens holding means of the lens well or wells of the device. The lens well or wells and the reservoir are filled with disinfecting and cleaning solution according to the above-described process. The device is then turned on by the user.
In a first step, opposite electrical potentials are applied to the opposing electrodes in the well or wells by action of the control means, causing the two opposing electrodes to exhibit opposite polarities. No potential need be applied to the reservoir electrode during this initial step.
An electric field is established between the oppositely charged electrodes in the electrolytic buffer solution of the well or wells. The electric field generated causes contaminants on the contact lenses to become charged and attracted to the oppositely charged electrode, thereby cleaning the lenses electrophoretically.
At the same time, the opposite electric potentials applied to the opposing electrodes causes an electrolytic reaction to occur in the halide-containing electrolytic buffer solution at the positive and negative electrodes.
At the positive electrode, the halide in the buffer solution, for example Cl - , which is likely in salt form such as NaCl, is converted to the halogen form Cl 2 . The reaction taking place at the surface of this electrode is:
NaCl→1/2Cl.sub.2 +Na.sup.+ +e.sup.-
Other reactions taking place at the positive and negative electrodes have essentially no effect on the pH of the solution due to use of the electrolytic buffer solution.
The first step is continued for a sufficient length of time, at the particular electric potentials applied to the electrodes, to disinfect and clean the lenses of contaminants.
Then, in a second step, the polarity of the electrodes is changed. A positive charge is applied to the reservoir electrode, and a negative charge is applied to both opposing electrodes in the lens well or wells.
The second step has the effect of reversing the electrolytic reaction which forms the halogen Cl 2 from the halide. During this step, the halogen is converted back to its halide salt form. The surfaces of the lens well electrodes are also cleaned of contaminants during this polarity changing process.
The second step is continued for a sufficient length of time to eliminate or at least reduce the concentration of halogen in the lens well or wells to such an amount that no rinsing of the lenses is necessary before insertion of the lenses into the eye of the wearer.
The foregoing constitutes a summary of the lens care system of the present invention. By way of example, the preferred embodiments of the present invention will be described with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-D are illustrations of a first embodiment of the contact lens care system of the present-invention having a reservoir and a single lens well.
FIGS. 2A-C are illustrations of a second embodiment of the contact lens care system of the present invention having a reservoir and two lens wells.
FIGS. 3A-C are illustrations of a variation of the second embodiment shown in FIGS. 2A-C showing a different well electrode structure.
FIGS. 4A-C are illustrations of a third embodiment of the contact lens care system of the present invention having a reservoir and two lens wells.
FIGS. 5A-C are illustration of a variation of the third embodiment shown in FIGS. 4A-C showing a different well electrode structure.
FIGS. 6A-B are illustrations of the control unit and housing unit in the form of separate units which are connected to each other by a cable or an interlocking arrangement.
FIGS 7A-B are illustrations of the control unit and housing unit in the form of separate units, wherein the housing unit is removably insertable into the control unit.
The unit of measurement shown in the drawings is inches.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1A-D, a preferred device of the present invention is shown which comprises a housing 9 and a top 8 which may be made out of any conventional non-electrical conducting material.
The housing 9 contains one lens well 4 for immersing the contact lens and a reservoir 7. The lens well 4 and reservoir 7 are connected by a narrow channel 5 made of a conventional material. A solution displacement block 6 fits into the upper portion of the reservoir.
The lens well 4 contains two opposing electrodes 1,2 for generating an electric field therebetween. The two lens well electrodes 1,2 are spaced apart for placing the contact lenses therebetween. In this embodiment, the contact lenses are held in a contact lens basket.
The electrodes 1,2 need not be spaced apart any specific distance, however the closer the distance the opposing electrode surfaces are spaced to each other, the less time is generally required to generate a disinfecting concentration of halogen in the well, and the less time is required to neutralize the halogen. Preferably, the electrodes are spaced apart a distance of about 3/16's of an inch or so, which allows a very short time period to be required to generate and neutralize the halogen concentration.
In this embodiment using a lens basket, the distance between the electrodes must be greater and is dictated by the size of the lens basket.
The reservoir 7 has one electrode 3 in this embodiment. A reservoir is not limited to one electrode and may have two or more electrodes.
The electrodes are comprised of a conventional inert electrically conductive material, e.g. platinum, graphite, palladium, etc., or a conductive polymer.
The upper electrode may be integrally connected to the top 8 of the device. Preferably, the top 8 is hinged to the housing so that the electrical connection between the upper electrode and the rest of the device is protected.
In this embodiment, the opposing surfaces of the two opposing well electrodes are flat to accomodate a lens basket 10. The lenses may be held in the lens basket 10 in any orientation but it is preferable that the lenses be oriented in a horizontal direction one over the other. The lens basket may be of the conventional type which hold two lenses in separate side by side compartments and which have separate openings marked with an indication of which lens (left or right) is placed in the respective compartment.
In addition to the above-described features, the device must have a means for operatively connecting the electrodes to a power source, e.g. a DC power source. This is not specifically shown in the figures.
Also not shown is the control means of the device, which preferably is a control or programming unit for automatically controlling the electrode polarity and potential of the electrodes, as well as the timing and duration of the process steps, so that the optimum disinfection and cleaning efficacy is obtained.
Referring to FIGS. 2A-C, a second preferred embodiment of the present invention is shown which has two lens wells 4 which are connected so that the electrolytic buffer solution may intermix.
The opposing surfaces of the lens well electrodes are complementary concave and convex configurations for placing a lens therebetween. The surfaces of the lens well electrodes are preferably spaced apart about 3/16's of an inch or so in order to minimize the time required to complete the disinfecting and cleaning process.
Referring to FIGS. 3A-C, a variation of the second preferred embodiment is shown, in which the lens well electrodes have a configuration which is a mirror image to those shown in FIGS. 2A-C.
Referring to FIGS. 4A-C, a third preferred embodiment is shown having two lens wells 4 which are isolated from each other so that the electrolytic buffer solution in the lens wells may not intermix.
Referring to FIGS. 5A-C, a variation of the third preferred embodiment is shown, in which the well electrodes have the opposite configuration to those shown in FIGS. 4A-C.
Referring to FIGS. 6A-B, the control unit may be a separate unit from the housing unit and they may be connected to each other by cable or an interlocking socket arrangement. Alternatively, the control unit may be permanently incorporated in the housing unit.
FIGS. 7A-B shows another embodiment of the control unit and the housing unit as separate units, in which case the housing unit is insertable into and removable from the control unit, for example as illustrated in FIGS. 7A-B. Alternatively, the control unit may be insertable into and removable from the housing unit.
In referring to the control and housing units above, the term "control unit" means a unit containing the electronic circuitry for operatively connecting the electrodes with the power source and for controlling the polarity of the electrodes. The control unit may optionally contain a power pack (AC or DC battery), an automatic switching mechanism, indicator means, etc. The term "housing unit" means a unit containing the lens wells, reservoir, electrodes, lens baskets, etc.
The device may be designed so that it is turned on by the user using a hand-operated switching device. Alternatively, the device may be automatically activated, for example, upon the insertion of the housing unit into the control unit (embodiment of FIGS. 7A-B), or the connection of the housing unit with the control unit (embodiment of FIGS. 6A-B), or upon closing of the top 8 of the device (such as in embodiment of FIGS. 1A-D).
The method of the present invention for cleaning and disinfecting contact lenses will now be explained in detail.
The present method comprises immersing a contact lens or lenses in a halide-containing electrolytic buffer solution which is contained in a well having two spaced apart electrodes. The electrodes and lens holding means are adapted to expose the surface of the contact lenses inserted therebetween to the disinfecting and cleaning solution.
The lens or lenses are placed by the user of the device in the lens holding means between the opposing surfaces of the two lens well electrodes.
The reservoir is filled with the halide-containing electrolytic buffer solution, and the solution displacement block is inserted in the reservoir. The solution displacement block forces halide-containing electrolytic buffer solution through the narrow channel into the lens well(s), so as to completely fill the channel and to immerse the contact lens or lenses contained in the lens well(s).
The halide-containing electrolytic buffer solution may contain any alkali or alkaline earth halide compounds such as NaCl, KCl, KBr, NaBr, etc. The electrolytic buffer solution is preferably a borate, phosphate or physiologically compatible buffer saline. The solution may contain a preservative as an optional ingredient. A protein removal agent may also be added to improve cleaning efficacy.
In the first step, a unidirectional electric field is generated in the halide-containing electrolytic solution by application of a potential voltage to the two electrodes, so that the two electrodes have an opposite polarity. Preferably, the polarity and potential applied to the electrodes is set according to a predetermined program of the control means.
The electric field causes the generation of the halogen from the halide in the lens well or wells. The electric field is maintained for a duration of time until a disinfecting concentration of the halogen is generated and until the lenses are disinfected. If a predetermined program is used, the duration of this step may be predetermined and set.
Then, the polarity of the electrodes is changed, so that the two well electrodes have a negative charge, and the reservoir electrode has a positive charge. This causes the reconversion of the halogen back to the halide. This step is maintained until the concentration of the halogen is substantially reduced or eliminated, so that the contact lenses need not be rinsed before inserting them into the eyes of the user. If a predetermined program is used, the initiation of this step, its duration, and the potential applied to the electrodes, may be predetermined and set.
Between the disinfection and neutralization steps, there may be another step whereby the polarity of the two lens electrodes is reversed and opposite from each other. This step causes the generation of a further amount of halogen, and the step helps better clean the surfaces of the lens well electrodes.
One of ordinary skill in the art will recognize that the same essential results of the present invention may be obtained by the application of different sequences of polarities to the various electrodes depending upon the timing sequence, etc., as well as by the application of different voltages and durations. These scenarios are intended to be fully covered by the present invention.
The following table summarizes typical operating conditions of the lens care system of the present invention and possible ranges of the operating conditions:
______________________________________Typical Operating ConditionsTime for step 1 (disinfection) 2 secondsTime for step 2 (neutralization) 10 minutesVoltage of steps 1 and 2 6 VConcentration of Cl.sub.2 generated 80 ppmat end of step 1Final Cl.sub.2 concentration at less than 3 ppmend of step 2Possible Ranqes for Operating ConditionsTime for step 1 (disinfection) 1 sec. to 10 minutesTime for optional disinfection 0 to 20 minutesstep between steps 1 and 2Time for step 2 (neutralization) 2 to 40 minutesVoltage of steps 1 and 2 1.0 V to 9 VVoltage for optional step 0 V to 6 VConcentration of Cl.sub.2 generated at least 10 ppmat end of step 1Final Cl.sub.2 concentration at less than 3 ppmend of step 2______________________________________
Examples 1-6
Using a device of the present invention according to FIGS. 5A-C, two soft contact lenses were placed in respective lens wells 4. The lens wells 4 and reservoir 7 were filled with a borate buffer saline solution. The top was placed on the housing and the electrodes were connected to the controller.
The controller which was used had the capability of supporting different voltages of from 0.0 V to 9.0 V and different polarities (+ or -). The controller also had at least three different output voltages and variable timing for every event requirement.
The device used could be provided with a rechargeable battery, and it could be programmed to operate under battery voltage conditions.
The specific settings of the controller concerning the potential voltage, polarity of the electrodes, and duration of each step, for each of Examples 1-6 are summarized in Table 1 below.
At the end of the whole process, the residual chlorine in the lens wells 4 was evaluated by a spectrophotometric method. The results for each example are shown in Table 1.
EXAMPLE 7
The procedure of Example 1 was duplicated, except that the time of event programming was lengthened, and the buffer solution employed was SOFTWEAR (TM), which contains 50-60 ppm hydrogen peroxide in a borate buffer saline. The residual chlorine is shown in Table 1.
From the foregoing results, it is demonstrated that the concentration of the halogen which can be generated by the method and device of the present invention reaches a very high level in a very short period of time. Thus, the disinfection time is very short. The halogen concentration may also be easily controlled by time and voltage.
Further, the overall time required for the entire process is quite short in comparison to the time required in conventional disinfecting methods and apparatuses.
Furthermore, by the construction and operation of the present device, the concentration of the disinfecting agent is essentially eliminated. And by the use of a halide-containing electrolytic buffer solution, the solution maintains a neutral pH (7.0+0.5). Therefore, rinsing of the contact lenses after cleaning is not required.
TABLE 1__________________________________________________________________________ Polarity of Potential Electrode Residual BufferExampleStep (V) 1 2 3 1a 2a Time Chlorine Saline__________________________________________________________________________1 1 6 - + 0 - + 2 sec 0.4 ppm Borate2 6 - - + - - 10 min2 1 6 - + 0 - + 2 sec 2.0 ppm Borate2 0 10 min3 6 - - + - - 10 min3 1 6 - + 0 - + 2 sec 0.3 ppm Borate2 6 - - + - - 20 min4 1 3 - + 0 - + 5 sec 0.1, 0.3 ppm Borate2 6 - - + - - 20 min5 1 3 - + 0 - + 5 sec 1.0 ppm Borate2 3 + - 0 + - 5 sec3 6 - - + - - 20 min6 1 3 - + 0 - + 10 sec 0.2 ppm Borate2 6 - - + - - 20 min7 1 3 - + 0 - + 3 min 1.1, 3.4 ppm SOFTWEAR ™2 6 - - + - - 20 min__________________________________________________________________________
It will be understood by those skilled in the art that various other arrangements than those described herein will occur to those skilled in the art, which arrangements are within the scope and spirit of the present invention. It is, therefore, to be understood that the invention is not intended to be limited to the specific embodiments disclosed herein but is extended to obvious variations and equivalents thereto.
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A contact lens care device and method for cleaning and disinfecting contact lenses. The invention utilizes both principles of electrophoresis and electrolysis. The device uses a halide-containing electrolytic buffer solution for disinfecting and cleaning. A halogen concentration is generated electrolytically from the halide in the contact lens containing well by the generation of an electrical field between the two electrodes disposed in the well. The field is maintained for a time sufficient to generate a concentration of halogen which can disinfect the lens. The lens is cleaned electrophoretically at the same time. Then, the conversion of the halide to halogen is reversed to remove the halogen from the contact lens containing well. This is done by generating an electrical field between the well electrodes and another electrode located in a reservoir connected to the well by a narrow channel or inert divider. The elimination of halogen is so complete that the lens does not need to be rinsed before insertion in the eye. The device may include an automatic control means.
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This is a division of application Ser. No. 913,071, filed June 6, 1978, now U.S. Pat. No. 4,235,261.
BACKGROUND OF THE INVENTION
The present invention relates to important improvements in the weft transport grippers for shuttleless looms, of the type wherein a first gripper (carrying) grasps the weft thread at one side of the loom and carries it to the centre of the warp shed, while the second gripper (drawing) receives the weft thread at the centre of the warp shed from the carrying gripper, and transports it to the opposite side of the loom, where it releases the same.
The pair of grippers according to the invention comprises grippers of reduced weight and dimensions which cooperate with each other without penetrating one into the other and which may move along a common plane, which may be differently oriented in respect of the plane of the loom reed.
SUMMARY OF THE INVENTION
The improved pair of weft transport grippers according to the invention is essentially characterized in that, in both grippers, the weft thread grasping and holding members are mounted on head parts of the grippers disposed on opposite sides of a sliding plane, along which said head parts move side by side, cooperating between them for grasping and releasing the weft thread. Said sliding plane may be parallel, perpendicular or differently inclined in respect of the plane of the loom reed.
The carrying gripper of the pair of grippers according to the invention is characterized by a rear part, whose side close to the sliding plane projects beyond said plane in respect of the head part of the gripper, so as to form a guide for the weft thread parallel to the plane itself, said head part comprising a pair of pegs for positioning the end of the weft thread, said pegs being arranged close to the free end of the thread grasping and holding means, on one side and on the other thereof, and in a position such as to cause the weft thread to be positioned between said guide and the first of said pegs only slightly inclined (about 25° at the most) in respect of the sliding plane.
Moreover, said carrying gripper mainly comprises a basic gripper body, the rear part of which is fixed to the gripper advancement strap and forms said guide for the weft thread, and the head part of which is equipped with said weft thread grasping and holding means, and a cover adapted to be applied on said basic body and comprising an opening for housing said weft thread grasping and holding means, said pegs projecting from said cover and fitting into said basic body or viceversa.
The drawing gripper of the same pair of grippers is also characterized by the fact that the thread guard of its head part comprises a profiled appendix, extending parallel to the gripper body for covering the weft thread grasping and holding means.
The invention also comprises shuttleless weaving looms using the aforespecified grippers.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a front view of a loom part corresponding to the warp shed, showing a first type of a pair of weft thread transport grippers according to the invention, in a thread exchange position;
FIG. 2 is a section along the line II-II of FIG. 1;
FIG. 3 is a top view according to the arrow III of the arrangement of FIG. 1;
FIG. 4 is a view similar to that of FIG. 1, but showing a modified embodiment of the pair of grippers according to the invention on the loom, in the position of weft thread exchange;
FIG. 5 is a top view according to the arrow V of the arrangement of FIG. 4;
FIG. 6 is a top view of a third embodiment of the pair of grippers according to the invention in a condition which slightly procedes the weft thread exchange between the two grippers;
FIG. 7 is a front view of the body part of the carrying gripper, with the cover removed;
FIG. 8 is a bottom plan view of FIG. 7;
FIG. 9 is a bottom plan view of the removed cover of the carrying gripper;
FIG. 10 is a front view of the removed cover of the carrying gripper; and
FIGS. 11 and 12 are a schematic side view and a fragmentary perspective view of the head part of the drawing gripper, illustrating the appendix for protecting the thread guard of said gripper.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in the drawings, the pair of grippers according to the invention comprises a carrying gripper 1 and a drawing gripper 2, in which the weft thread grasping and holding means 3 and 4 are mounted on head parts 5 and 6 of the grippers themselves which are arranged on one side and, respectively, on the other side of a plane α along which the gripper head parts 5 and 6 slide on each other in their working motion, cooperating between them with the mutually sliding parts of each disposed only on one side of that plane for exchanging the weft thread f.
In the arrangement of FIGS. 1 to 3, the plane α is perpendicular to the plane of the reed P, parallel to which are arranged the gripper advancement straps or tapes 7 and 8, sliding in special guiding supports 9, and the grippers themselves.
In the arrangement of FIGS. 4 and 5, the plane α and the grippers are again arranged as in FIGS. 1 to 3, while their advancement straps are arranged along a plane parallel to the plane α and move along the same.
In the arrangement of FIG. 6, the plane α is parallel to the plane of the reed P and the grippers and straps are arranged, more traditionally, perpendicular to said reed plane and parallel to the top plane of the sley (as well as perpendicular to the plane α).
Although not shown, other arrangements of the grippers and straps could be provided, with the plane α lying inclined to different extents in respect of the plane of the reed and of the plane of the sley.
The carrying gripper of the pair of grippers according to the invention (FIGS. 1 to 10) comprises a head part 5, in which are mounted the weft thread grapsing and holding members 3, consisting of a longitudinal elastic lamina 10, pressed by a leaf spring 11, which may for example correspond to those of U.S. Pat. No. 3,580,291 and of a pair of pegs 12 and 13, arranged close to the point of said elastic lamina, on one side and on the other thereof. The head comprises moreover a rear part 14, whose side close to the sliding plane α projects beyond said plane.
The carrying head 5 is formed (FIGS. 7 to 10) by two elements of plastic material associated with each other: a basic head body 16, the rear part of which 14' is fixed to the advancement strap 7, and the head part of which is equipped with the elastic lamina 10, for grasping and holding the weft thread, and with the associated leaf spring 11; and a cover 17, applied to the basic body 16 and comprising an opening 18 for the lamina 10 and related leaf spring 11. The rear part 14 of the cover 17 has its side close to the sliding plane α projecting beyond said plane and beyond the corresponding side of the rear part 14' of the underlying basic gripper body 16. On said cover side is formed a hollow guide 15 for the weft thread, which is parallel to and spaced away from the plane α. The pegs 12 and 13 are carried by the cover 17, being fitted into the assembly in appropriate seats in the body 16 (of course, it could also be viceversa).
The removed cover 17 is separately shown in FIGS. 9 and 10, which latter figure shows the cover in the same position as in FIG. 6.
The head part 5 of the carrying gripper 1 further comprises a top fin 19, emerging perpendicular from the end of the body 16 which is not covered by the cover 17, with the function of protecting the warp yarns by preventing the weft thread grasping members from hitting the same. It is moreover appropriate to create in the gripper body 16 a hardened zone cooperating with the elastic lamina 10, for example by applying into said body a hard metal element, or in some other way.
The drawing gripper 2 according to the invention has its head part 6 (FIGS. 11 and 12) shifted sideways in respect of the rear part 20 connected to the advancement strap 8. On the head part 6 of the gripper are arranged (FIGS. 11 and 12) weft thread grasping and holding means 4, of the type described in U.S. Pat. No. 4,040,454. The gripper 2 draws the weft thread from the gripper 1 when--as in FIGS. 1 to 6--these two members meet and their heads 5 and 6 come up side by side on a single side. Such means comprise a fixed hook 21 and an oscillating lever 22, whose head wedges into the hook 21 so as to lock therein the weft thread under the action of spring means 23 (FIGS. 1 to 6). According to the invention, the head part 6 of gripper 2 is provided (FIGS. 11 and 12) with a thread guard 24 comprising a profiled appendix 25 extending substantially parallel to the gripper 2 for covering the hook 21.
With the pair of grippers heretofore described and illustrated, the weft thread f will lie in the guide 15 of head part 5, in alignment with its feeding path and very slightly inclined (no more than 25°) in respect of this alignment (and thus in respect of the sliding plane α between the heads of the grippers) in the area between the guide 15 and the peg 12 of the head 5 of the gripper 1, namely in the area in which the weft thread is grasped by the grasping elements 4 of gripper 2. Between the peg 12 and the peg 13, the weft thread is instead arranged to extend between these pegs, being engaged by the elastic lamina 11.
The arrangement according to the invention introduces the use of light and slender grippers (particularly remarkable in the case of the carrying gripper, up to date always very bulky), which exchange the weft at the centre of the warp shed by simply coming close to each other with their head parts, on one side only, with evident progress and advantage compared to the known technique of inserting the whole head of the drawing gripper into an appropriate housing of the carrying gripper.
In fact, the surfaces of the two grippers coming into contact at the moment of thread exchange are reduced to a third, or even to a fourth, thereby preventing or highly reducing impacts, frictions, possible jamming and failed grasping of the weft thread.
A further remarkable improvement and advantage is obtained, according to the invention, thanks to the arrangement of the weft thread, which is slightly inclined in respect to its feeding alignment, in the gripping area between the guide 15 and the peg 12 of the head 5 of the carrying gripper 1. Thanks to this arrangement, the weft thread is not subjected, at the moment of exchange, to the traditional front impact (substantially at 90° over a very short thread length) by the hook of the drawing gripper; on the contrary, the engagement takes place very smoothly, progressively and over a very long thread length; this helps to prevent, or at least to highly reduce cases of tears, abrasions and weakening of the weft thread, in general, which compromise the proper outcome of the thread exchange. This latter may be carried out with a reduced braking of the thread and consequently with less breaks. Also the vibrations characteristic of the thread upon its exchange, are reduced, thereby improving even further the operation. On the other hand, it should also be said that it is the actual aforedescribed arrangement of the weft thread in the grasping area which allows the construction of compact and light grippers, which are well balanced as to the distribution of the masses and which make it hence possible--as confirmed by practical experience--to obtain weft insertion speeds which are clearly higher than those obtained with the traditional systems, though keeping the mechanical stresses within reasonable limits.
The reduced dimensions and the specific shape of the grippers, as described, allow one to eliminate in the carrying gripper according to the invention the normal profile protecting the warp yarns, with remarkable advantages and, that is, extreme easiness of insertion, and consequent reduction of the weft stresses and of the brakings required in order to overcome the inertia of the thread, as well as the facilitated drawing out of the weft thread from the carrying gripper upon thread exchange, due to the absence of slippage and consequent frictions which normally take place on the thread guard. The easiness of the weft disinsertion is also improved by the considerable simplicity and freedom of the weft thread guiding elements on the carrying gripper.
Finally, it should be noted that the appendix provided on the drawing gripper to protect the hook, favours the grasping of the weft by the appropriate members of such gripper, in that it opposes the possible "ballon" of the weft thread resulting from the deceleration of the grippers movement upon thread exchange, thus allowing one to reduce the braking power for the weft thread to be inserted.
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A pair of grippers for shutterless looms, of the type wherein a first gripper (carrying) grasps the weft thread at one side of the loom and carries it to the center of the warp shed, while the second gripper (drawing) receives the weft thread at the center of the warp shed from the carrying gripper, and transports it to the opposite side of the loom, where it releases the same. The weft thread grasping and holding members are mounted on head parts of the grippers disposed on opposite sides of a sliding plane. Along said sliding plane said head parts move side by side, cooperating between them for grasping and releasing the weft thread.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. Non-Provisional application Ser. No. 11/023,667, filed Dec. 28, 2004, which is hereby incorporated by reference as though fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] a. Field of the Invention
[0003] The present invention relates to catheters and sheaths and methods of using catheters and sheaths. More particularly, the present invention relates to a fixed dimensional control handle for steerable catheters and sheaths and methods of manufacturing and using such an handle, with the control handle generally maintaining its exterior dimensions during operation thereof.
[0004] b. Background Art
[0005] Catheters (i.e., catheters or sheaths) that have flexible tubular bodies with deflectable distal ends and control handles for controlling distal end deflection are used for many noninvasive medical procedures. For example, catheters having conductive electrodes along the distal ends of their bodies are commonly used for intra-cardiac electrophysiology studies. The distal end of a catheter body is typically placed into a patient's heart to monitor and/or record the intra-cardiac electrical signals during electrophysiology studies or during intra-cardiac mapping. The orientation or configuration of the distal end is controlled via an actuator located on the catheter's control handle, which remains outside the patient's body. The electrodes conduct cardiac electrical signals to appropriate monitoring and recording devices that are operatively connected at the control handle.
[0006] Typically, a catheter body is cylindrical and electrically non-conductive. The catheter body includes a flexible tube constructed from polyurethane, nylon or other electrically non-conductive flexible material. The catheter body further includes braided steel wires or other non-metallic fibers in its wall as reinforcing elements. Each electrode has a relatively fine electrically conductive wire attached thereto and extending through the catheter body. The conductive wire extends from the distal end to a proximal end where electrical connectors such as plugs or jacks are provided to be plugged into a corresponding socket provided in a recording or monitoring device.
[0007] The distal portion of the catheter body is selectively deformed into a variety of curved configurations using the actuator on the control handle. The actuator is commonly internally linked to the distal portion of the catheter body by at least one deflection wire. Some catheter bodies employ a single deflection wire, which is pulled (i.e., placed in tension) by the actuator in order to cause the distal portion of the catheter body to deform. Other catheter bodies have at least two deflection wires, where the displacement of one wire (i.e., placing one wire in tension) results in the other wire going slack (i.e., the wire does not carry a compressive load). In such catheters, where the deflection wires are not adapted to carry compressive loads (i.e., the deflection wires are only meant to be placed in tension), the deflection wires are commonly called pull or tension wires.
[0008] To deform the distal end of the catheter body into a variety of configurations, a more recent catheter design employs a pair of deflection wires that are adapted such that one of the deflection wires carries a compressive force when the other deflection wire carries a tensile force. In such catheters, where the deflection wires are adapted to carry both compressive and tension loads, the deflection wires are commonly called push/pull or tension/compression wires and the corresponding catheter actuators are called push-pull actuators. U.S. Pat. No. 5,861,024 to Rashidi, which issued Jan. 19, 1999, is representative of a push-pull actuator of this type, and the details thereof are incorporated herein by reference.
[0009] Prior art control handles for controlling distal end deflection of catheter bodies have several drawbacks that adversely impact the handles' ability to be operated precisely by a single hand. First, the control handles are often excessively bulky. Second, the control handles are often inadequate with respect to their ability to provide finely controlled deflection adjustment for the distal end of the catheter body. Third, the control handles often provide inadequate deflection wire travel for a desired medical procedure. Fourth, the control handles often have a mechanical advantage that is less than desirable and, as a result, require significant effort to operate on the part of a user. Fifth, once a desired body distal end deflection has been reached, the control handles typically require the physician to take a conscious step to maintain the catheter at the desired deflection. Sixth, the wire displacement mechanisms within the control handles have a tendency to permanently deform the deflection wires. Seventh, the wire displacement mechanisms within the control handles typically make it difficult, if not impossible, to provide a lumen that runs uninterrupted from the proximal end of the control handle to the distal end of the catheter body.
[0010] There is a need in the art for a catheter control handle that offers improved single hand operation and deflection adjustment of the distal end of the catheter body. There is also a need in the art for such a handle with a lumen there through. There is also a need in the art for a method of manufacturing and using such a control handle.
BRIEF SUMMARY OF INVENTION
[0011] A fixed dimensional and bi-directional steerable catheter control handle may include an apparatus for imparting a tensile force to deflect a distal portion of a catheter while maintaining its exterior dimensions. The apparatus may include a handle grip including generally oval or circular cross-sections of generally predetermined exterior dimensions, and a longitudinal axis. A flexible elongate member may include proximal and distal end portions, with the proximal end portion being coupled to the handle grip. An adjustment knob may include a generally circular cross-section of generally predetermined exterior dimensions, and may be rotatably coupled to the handle grip around the longitudinal axis of the handle grip. One or more elongate deflection members may be operably coupled to the adjustment knob and to the distal end portion of the elongate member. Rotation of the adjustment knob may impart a tensile force to the elongate deflection member thereby causing the distal end portion of the elongate member to deflect from a prior configuration while maintaining the generally predetermined exterior dimensions of the handle grip and the adjustment knob.
[0012] For the apparatus described above, in an embodiment, the elongate deflection member may include a filament, a braided cord, or a resin-based member. In an embodiment, the adjustment knob may be operably coupled to an intermediate body portion or a distal portion of the handle grip. In an embodiment, the elongate deflection member may include a first pull wire. The apparatus, in an embodiment, may include one or more additional pull wires operably coupled to the adjustment knob.
[0013] For the apparatus described above, in an embodiment, the apparatus may include means for simultaneously imparting a tensile force to the first pull wire and releasing a tensile force on the additional pull wire. The adjustment knob may include an interior surface forming an aperture generally orthogonally oriented with respect to the longitudinal axis of the handle grip, with the interior surface including one or more sets of threaded grooves which cooperate with the means. The means may include a pair of generally axially displaceable members disposed within the handle grip, and rotation of the adjustment knob may impart opposing forces to the axially displaceable members.
[0014] For the apparatus described above, in an embodiment, the elongate member may include one or more longitudinal lumens. In an embodiment, the apparatus may include one or more electrodes coupled to the elongate member. The elongate member, in an embodiment, may include a biocompatible electrically insulative material. The electrically insulative material may be a flexible material. Alternatively, the electrically insulative material may include a polyurethane material or a nylon material. The apparatus, in an embodiment, may include one or more reinforcing elements disposed within a portion of the elongate member. The reinforcing element may include braided members, which may include a conductive material.
[0015] For the apparatus described above, in an embodiment, the elongate member may include a segment of a braided metallic wire and/or a non-metallic fiber. The apparatus, in an embodiment, may include a hemostasis valve coupled to the handle grip. In an embodiment, an exterior surface of the adjustment knob may includes a generally longitudinal groove and/or a generally longitudinal protuberance.
[0016] For the apparatus described above, in an embodiment, the prior configuration may include a substantially straight configuration. In an embodiment, the elongate deflection member may include an elongate wire. In an embodiment, the apparatus may include an anchor ring coupled to the distal portion of the elongate member, and the elongate deflection member may include one or more elongate pull wires coupled to the anchor ring.
[0017] In an embodiment, an apparatus for imparting a tensile force to deflect a distal portion of a catheter while maintaining its exterior dimensions may include a handle grip including a cross-section of generally predetermined exterior dimensions, and a longitudinal axis. A flexible elongate member may include proximal and distal end portions, with the proximal end portion being coupled to the handle grip. An adjustment knob may include a cross-section of generally predetermined exterior dimensions, and be rotatably coupled to the handle grip around the longitudinal axis of the handle grip. One or more elongate deflection members may be operably coupled to the adjustment knob and to the distal end portion of the elongate member. Rotation of the adjustment knob may impart a tensile force to the elongate deflection member thereby causing the distal end portion of the elongate member to deflect from a prior configuration while maintaining the generally predetermined exterior dimensions of the handle grip and the adjustment knob.
[0018] For the apparatus described above, the handle grip may include a generally oval or circular cross-section, and in an embodiment, the adjustment knob may include a generally circular cross-section.
[0019] In an embodiment, an apparatus for imparting a tensile force to deflect a distal portion of a catheter while maintaining its exterior dimensions may include a substantially hollow handle grip having a tactile outer surface having a longitudinal axis. An adjustment knob having a tactile outer surface may be coupled to the handle grip approximately equidistant from the longitudinal axis. A relatively thin elongated flexible body may have a distal end portion and a proximal portion, with the proximal portion coupled to the handle grip. One or more elongated members may be operatively coupled to the adjustment knob and to the distal end portion. Means may be disposed within the handle grip and operatively coupled to the adjustment knob for imparting a tensile force to the elongated member when the adjustment knob is rotated about the longitudinal axis so that the distal end portion of the flexible body deflects from a first configuration to a second configuration. The tactile outer surfaces of the handle grip and the adjustment knob may be substantially unchanged when the flexible body is disposed in the first and second configurations.
[0020] For the apparatus described above, the handle grip may include a generally oval or circular cross-section, and in an embodiment, the adjustment knob may include a generally circular cross-section.
[0021] The foregoing and other aspects, features, details, utilities, and advantages of the invention will be apparent from reading the following description and claims, and from reviewing the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is an isometric view of one embodiment of the present invention, which is a control handle for a catheter or sheath.
[0023] FIG. 2 is an isometric view of the handle exploded to show its various components.
[0024] FIG. 3 is a longitudinal sectional elevation of the handle taken along section line AA of FIG. 1 .
[0025] FIG. 4 is an isometric view of the right and left slides with their respective deflection wires attached.
[0026] FIG. 5 is a side elevation of an exemplary slide illustrating a means of securing a deflection wire to the proximal end of the slide.
[0027] FIG. 6 is a longitudinal sectional elevation of the adjusting knob taken along section line AA of FIG. 1 .
[0028] FIG. 7 is a plan view of another embodiment of the handle.
[0029] FIG. 8 is a side elevation of the handle depicted in FIG. 7 .
[0030] FIG. 9 is an isometric view of the distal end of the handle depicted in FIG. 7 .
[0031] FIG. 10 is a longitudinal sectional plan view of the handle taken along section line BB of FIG. 9 .
[0032] FIG. 11 is a longitudinal sectional plan view of the knob taken along section line BB in FIG. 9 .
[0033] FIG. 12 is a right side isometric view of the slides displaced about the wire guide.
[0034] FIG. 13 is a left side isometric view of the slides displaced about the wire guide.
[0035] FIG. 14 is a longitudinal sectional elevation of the handle grip taken along section line CC in FIG. 7 .
[0036] FIG. 15 is a latitudinal sectional elevation of the handle grip taken along section line DD in FIG. 8 .
[0037] FIG. 16 is an isometric view of the distal end of a control handle for a catheter wherein the handle has a through lumen.
[0038] FIG. 17 is an isometric view of the slides, the wire guide, the wire tubing, and the lumen illustrating the path the lumen takes through the handle.
[0039] FIG. 18 is an elevation view of the extreme proximal end surfaces of the slides as viewed from arrow A in FIG. 17 and illustrating the path the lumen and wire tubing take into the passage formed by the channels of the slides.
[0040] FIG. 19 is an isometric view of the lumen, deflection wires, and electrical wires of the tube exiting the catheter body-retaining nut on the distal end of the handle.
[0041] FIG. 20 is an isometric view of another embodiment of the handle exploded to show its various components.
[0042] FIG. 21 is a longitudinal sectional elevation taken along section line ZZ in FIG. 20 .
[0043] FIG. 22 is isometric views of the slides oriented to show their respective portions of the passage and their planar slide faces.
[0044] FIG. 23 is an isometric view of another embodiment of the handle exploded to show its various components.
[0045] FIG. 24 is a longitudinal sectional elevation of the handle taken along section line YY of FIG. 23 .
[0046] FIG. 25 is the same longitudinal sectional elevation of the adjusting knob as depicted in FIG. 24 , except the adjusting knob is shown by itself.
[0047] FIG. 26 is a side elevation of the slides.
[0048] FIG. 27A is a latitudinal sectional elevation of the handle, as taken along section line XX in FIG. 24 , wherein the wire guide has a square cross section.
[0049] FIG. 27B is the same latitudinal sectional elevation depicted in FIG. 27A , except the wire guide has a circular cross section and a key/groove arrangement.
[0050] FIG. 28 is a side elevation of one embodiment of the wire guide equipped with a groove.
[0051] FIG. 29 is a longitudinal sectional elevation of another embodiment of the handle taken along section line YY of FIG. 23 .
[0052] FIG. 30 is a longitudinal sectional plan view of the handle depicted in FIG. 29 taken along section line VV in FIG. 23 and wherein section line VV forms a plane that is perpendicular to the plane formed by section line YY in FIG. 23 .
[0053] FIG. 31 is an isometric view of one embodiment of the wire guide.
[0054] FIG. 32 is a latitudinal sectional elevation of the handle as taken along section line WW in FIG. 29 .
[0055] FIG. 33 is a longitudinal sectional elevation of the handle taken along section line AA of FIG. 1 .
[0056] FIG. 34 is a side elevation of an exemplary slide employed in the embodiment depicted in FIG. 33 .
[0057] FIG. 35 is a longitudinal sectional elevation of the adjusting knob taken along section line AA of FIG. 1 .
[0058] FIG. 36 is a diagrammatic illustration of the control handle of the subject invention being employed in a surgical procedure on a patient.
DETAILED DESCRIPTION OF THE INVENTION
[0059] Referring FIG. 1 is an isometric view of one embodiment of the present invention. which is a control handle 2 for a flexible tubular, body 4 of a catheter 5 . Throughout this specification, the term catheter is meant to include, without limitation, catheters, sheaths and similar medical devices. As shown in FIG. 1 , in one embodiment, the distal end of the handle 2 is connected to the catheter body 4 and the proximal end of the handle 2 is connected to tubing 6 that contains electrical wire and extends to an electrical connector 8 . The handle 2 includes an adjusting knob 10 and a handle grip 12 . As will become clear from this specification, the handle 2 of the present invention is advantageous in that it is compact and allows a user to manipulate the catheter body's extreme distal end 14 in a bi-directional manner by pivoting the adjusting knob 10 relative to the handle grip 12 in one direction or the other about the longitudinal axis of the handle 2 . Furthermore, in one embodiment, the handle 2 has a lumen that runs uninterrupted from the proximal end of the handle 2 to the extreme distal end 14 of the catheter body 4 . This lumen can be used to provide contrast injection for guide wire insertion.
[0060] For a more detailed discussion of the handle 2 , reference is now made to FIGS. 2 and 3 . FIG. 2 is an isometric view of the handle 2 exploded to show its various components. FIG. 3 is a longitudinal sectional elevation of the handle 2 taken along section line AA of FIG. 1 .
[0061] As shown in FIGS. 2 and 3 , the adjusting knob 10 is pivotally attached to a mounting shaft (i.e., a slide base or base portion) 16 contained within the handle grip 12 . To pivotally attach the knob 10 to the mounting shaft 16 , a dowel pin 18 is inserted into a pinhole 20 in the distal end of the shaft 16 and mates with a groove 22 in a hub portion 23 of the knob 10 . A silicone o-ring 24 exists between the hub portion 23 of the knob 10 and the distal end of the shaft 16 .
[0062] As indicated in FIGS. 2 and 3 , a wire guide 26 is positioned within the adjusting knob 10 and is held in place by a retaining ring 28 . A right slide or member 30 and a left slide or member 32 are slideably positioned within a slot (i.e., a slide compartment) 34 in the mounting shaft 16 . A catheter body-retaining nut 36 is used to secure the catheter body 4 to the distal end of the wire guide 26 .
[0063] As illustrated in FIG. 3 , a pair of deflection wires 38 extend from the extreme distal end 14 of the body 4 , through the body 4 , the wire guide 26 and a passage 40 formed between the two slides 30 , 32 , to a point near a proximal portion of the slides 30 , 32 . Each wire 38 then affixes to an individual slide 30 , 32 via a retention screw 42 .
[0064] For a more detailed discussion of the slides 30 , 32 and their relationship to the deflection wires 38 , reference is now made to FIG. 4 , which is an isometric view of the deflection wires 38 a , 38 b attached to the right and left slides 30 , 32 . As shown in FIG. 4 , the slides 30 , 32 , which are mirror images of each other, each have a rectangular box-like proximal portion 44 and a half-cylinder distal portion 46 . Each proximal portion 44 has a generally planar outer sidewall and bottom wall. These planar surfaces slideably displace against the generally planar sides and bottom of the slot 34 , which act as thrust surfaces for the slides 30 , 32 .
[0065] Each half-cylinder distal portion 46 is hollowed out along its longitudinal axis to form the passage 40 through which the deflection wires 38 a , 38 b and, as indicated in FIG. 3 , the narrow proximal portion of the wire guide 26 extend when the slides 30 , 32 are in the assembled handle 2 . Each slide 30 , 32 has a planar slide face 48 that is meant to slideably abut against the planar slide face 48 of the opposing slide 30 , 32 . Thus, as illustrated in FIG. 2 , when the planar slide faces 48 of the slides 30 , 32 abut against each other and the extreme proximal ends of each slide 30 , 32 are flush with each other, the half-cylinder distal portions 46 of each slide 30 , 32 combine to form a complete cylinder with a channel or passage 40 there through.
[0066] As shown in FIG. 4 , in one embodiment, the proximal end of each deflection wire 38 a , 38 b forms a loop 50 through which a retention screw 42 passes to secure the wire 38 a , 38 b to the proximal portion of the respective slide 30 , 32 . As indicated in FIG. 5 , which is a side elevation of an exemplary slide 30 , in one embodiment, the proximal end of each deflection wire 38 forms a knot 52 . The wire 38 passes through a hollow tension adjustment screw 54 and the knot 52 abuts against the head 55 of the screw 54 , thereby preventing the wire 38 from being pulled back through the screw 54 . In one embodiment, the screw's longitudinal axis and the longitudinal axis of the slide 30 , 32 are generally parallel. Each tension adjustment screw 54 is threadably received in the proximal end of its respective slide 30 , 32 . Tension in a wire 38 may be increased by outwardly threading the wire's tension adjustment screw 54 . Conversely, tension in a wire 38 may be decreased by inwardly threading the wire's tension adjustment screw 54 .
[0067] As can be understood from FIG. 4 , in one embodiment where the wires 38 a , 38 b are intended to only transmit tension forces, the wires 38 a , 38 b may deflect or flex within an open area 45 defined in the proximal portion 44 of each slide 30 , 32 when the slides 30 , 32 displace distally. Similarly, as can be understood from FIG. 5 , in another embodiment where the wires 38 are intended to only transmit tension forces, the wires 38 may slide proximally relative to the screw 54 when the slides 30 , 32 displace distally.
[0068] As shown in FIG. 4 , in one embodiment, the outer circumference of the half-cylinder distal portion 46 of the right slide 30 is threaded with a right-hand thread 56 , and the outer circumference of the half-cylinder distal portion 46 of the left slide 32 is threaded with a left-hand thread 58 . In one embodiment, the outer circumference of the half-cylinder distal portion 46 of the right slide 30 is threaded with a left-hand thread, and the outer circumference of the half-cylinder distal portion 46 of the left slide 32 is threaded with a right-hand thread.
[0069] For a better understanding of the relationship of the slide threads 56 , 58 to the rest of the handle 2 , reference is now made to FIG. 6 , which is a longitudinal sectional elevation of the adjusting knob 10 taken along section line AA of FIG. 1 . As indicated in FIG. 6 , a cylindrical hole or shaft 60 passes through the knob 10 along the knob's longitudinal axis. In the hub portion 23 of the knob 10 , the inner circumferential surface of the shaft 60 has both right hand threads 62 and left hand threads 64 . These internal threads 62 , 64 of the knob 10 mate with the corresponding external threads 56 , 58 of the slides 30 , 32 . More specifically, the right internal threads 62 of the knob 10 mate with the right external threads 56 of the right slide 30 , and the left internal threads 64 of the knob 10 mate with the left external threads 58 of the left slide 32 .
[0070] Thus, as can be understood from FIGS. 2 , 3 , 4 and 6 , in one embodiment, as the knob 10 is rotated clockwise relative to the longitudinal axis of the handle 2 , the internal and external right threads 62 , 56 engage and the internal and external left threads 64 , 58 engage, thereby causing simultaneous opposed displacement of the right and left slides 30 , 32 longitudinally within the slot 34 in the handle 10 . Specifically, because of the threading arrangement of the knob 10 and the slides, 30 , 32 , the right slide 30 moves distally within the slot 34 and the left slide 32 moves proximally within the slot 34 when the knob 10 is rotated clockwise relative to the handle grip 12 of the handle 2 . Conversely, when the knob 10 is rotated in a counterclockwise manner relative to the handle grip 12 of the handle 2 , the right slide 30 moves proximally within the slot 34 and the left slide 32 moves distally within the slot 34 .
[0071] As can be understood from FIGS. 4 and 6 , when the knob 10 is rotated such that the right slide 30 is urged distally and the left slide 32 is urged proximally, the deflection wire 38 a connected to the right slide 30 is placed into compression and the deflection wire 38 b connected to the left slide 32 is placed into tension. This causes the extreme distal end 14 of the catheter body 4 to deflect in a first direction. Conversely, when the knob 10 is rotated such that the right slide 30 is urged proximally and the left slide 32 is urged distally, the deflection wire 38 a connected to the right slide 30 is placed into tension and the deflection wire 38 b connected to the left slide 32 is placed into compression. This causes the extreme distal end 14 of the catheter body 4 to deflect in a second direction that is opposite the first direction.
[0072] The control handle 2 of the present invention as described has several advantages. First, the handle 2 is compact and may be operated with a single hand. Second, the threaded slides 30 , 32 and knob 10 allow a physician to make fine, controlled adjustments to the bend in the distal end 14 of the catheter body 4 . Third, once the knob 10 is rotated so as to cause a bend in the distal end 14 of the catheter body 4 , the threads 56 , 58 , 62 , 64 interact to maintain the bend without requiring any action on the physician's part. Fourth, because the slides 30 , 32 simply displace distally and proximally along the longitudinal axis of the handle 2 , they are less likely to permanently deform the wires 38 as compared to the wire displacement mechanisms in some prior art handles. Fifth, the threads 56 , 58 , 62 , 64 are mechanically advantageous in that they provide increased deflection wire travel and reduced actuation effort for the physician, as compared to some prior art handles.
[0073] While FIGS. 2-6 depict an embodiment where the slides 30 , 32 have external threads 56 , 58 and the knob 10 has internal threads 62 , 64 , in other embodiments the threading arrangement is reversed. For a discussion of one such embodiment, reference is made to FIGS. 33-35 . FIG. 33 is a longitudinal sectional elevation of the handle 2 taken along section line AA of FIG. 1 . FIG. 34 is a side elevation of an exemplary slide employed in the embodiment depicted in FIG. 33 . FIG. 35 is a longitudinal sectional elevation of the adjusting knob taken along section line AA of FIG. 1 .
[0074] A comparison of the embodiment depicted in FIGS. 33-35 to the embodiment depicted in FIGS. 3 , 5 and 6 reveals that the two embodiments are generally the same, except as will be described in the following discussion of FIGS. 33-35 . Reference numbers utilized in FIGS. 33-35 pertain to the same or similar features identified by the same reference numbers in FIGS. 3 , 5 and 6 .
[0075] As shown in FIG. 33 , the adjusting knob 10 is pivotally attached to a mounting shaft (i.e., a slide base or base portion) 16 contained within the handle grip 12 . A wire guide 26 is positioned within the adjusting knob 10 . Like the embodiment depicted in FIG. 2 , the embodiment illustrated in FIG. 33 includes a right slide or member 30 and a left slide or member 32 that are slideably positioned within a slot (i.e. a slide compartment) 34 in the mounting shaft 16 .
[0076] As can be understood from FIG. 34 , the slides 30 , 32 , which are mirror images of each other, each have a rectangular box-like proximal portion 44 and a distal portion 46 that may be rectangular or half-cylindrical. Each proximal portion 44 has a generally planar outer sidewall and bottom wall. These planar surfaces slideably displace against the generally planar sides and bottom of the slot 34 , which act as thrust surfaces for the slides 30 , 32 .
[0077] Each distal portion 46 is hollowed out to form half of a cylindrical passage 40 that is created when the slides 30 , 32 are abutted against each other in a side-by-side relationship. Thus, each distal portion 46 of each slide 30 , 32 includes an inner circumferential surface, which when combined with the inner circumferential surface of the other slide 30 , 32 , defines the cylindrical passage 40 .
[0078] As indicated in FIG. 34 , in one embodiment, the inner circumferential surface of the right slide 30 is threaded with a right-hand thread 56 . Similarly, as can be understood from FIG. 34 , the inner circumferential surface of the left slide 32 is threaded with a left-hand thread 58 . Thus, the distal portion 46 of each slide 30 , 32 is equipped with internal threads. In another embodiment, the inner circumferential surface of the right slide 30 is threaded with a left-hand thread 58 . Similarly, the inner circumferential surface of the left slide 32 is threaded with a right-hand thread 56 .
[0079] As indicated in FIG. 35 , the knob 10 includes an outer hub 23 a surrounding an inner hub 23 b . A space 65 exists between, and is defined by, the inner and outer hubs 23 a , 23 b . The space 65 is adapted to receive the distal ends 46 of each slide 30 , 32 . The outer circumferential surface of the inner hub 23 b has both right hand threads 62 and left hand threads 64 . These external threads 62 , 64 of the knob 10 mate with the corresponding internal threads 56 , 58 of the slides 30 , 32 . More specifically, the right external threads 62 of the knob 10 mate with the right internal threads 56 of the right slide 30 , and the left external threads 64 of the knob 10 mate with the left internal threads 58 of the left slide 32 .
[0080] As can be understood from FIG. 33 , in one embodiment, as the knob 10 is rotated clockwise relative to the longitudinal axis of the handle 2 , the internal and external right threads 56 , 62 engage and the internal and external left threads 58 , 64 engage, thereby causing simultaneous opposed displacement of the right and left slides 30 , 32 longitudinally within the slot 34 in the handle 10 . Specifically, because of the threading arrangement of the knob 10 and the slides, 30 , 32 , the right slide 30 moves distally within the slot 34 and the left slide 32 moves proximally within the slot 34 when the knob 10 is rotated clockwise relative to the handle grip 12 of the handle 2 . Conversely, when the knob 10 is rotated in a counterclockwise manner relative to the handle grip 12 of the handle 2 , the right slide 30 moves proximally within the slot 34 and the left slide 32 moves distally within the slot 34 .
[0081] As can be understood from FIG. 33 , when the knob 10 is rotated such that the right slide 30 is urged distally and the left slide 32 is urged proximally, the deflection wire 38 connected to the right slide 30 is placed into compression and the deflection wire 38 connected to the left slide 32 is placed into tension. This causes the extreme distal end 14 of the catheter body 4 to deflect in a first direction. Conversely, when the knob 10 is rotated such that the right slide 30 is urged proximally and the left slide 32 is urged distally, the deflection wire 38 connected to the right slide 30 is placed into tension and the deflection wire 38 connected to the left slide 32 is placed into compression. This causes the extreme distal end 14 of the catheter body 4 to deflect in a second direction that is opposite the first direction.
[0082] For a detailed discussion of another embodiment of the handle 2 of the present invention, reference is now made to FIGS. 7 , 8 and 9 . FIG. 7 is a plan view of the handle 2 . FIG. 8 is a side elevation of the handle 2 . FIG. 9 is an isometric view of the distal end of the handle 1
[0083] As shown in FIGS. 7-9 , the handle 2 includes an adjusting knob 10 on its distal end and a handle grip 12 on its proximal end. As can be understood from FIGS. 7-9 , in one embodiment, the knob 10 has a generally circular cross-section and the handle grip 12 has a generally oval cross-section. In one embodiment, both the knob 10 and the handle grip 12 have generally circular cross-sections. The oval cross-section of the handle grip 12 is advantageous because it provides the physician with a tactile indication of the catheter's rotational position.
[0084] For a more detailed discussion of the components of the handle 2 , reference is now made to FIG. 10 , which is a longitudinal sectional plan view of the handle 2 taken along section line BB of FIG. 9 . As shown in FIG. 10 , an o-ring 24 is located between the handle grip 12 and a groove in the knob 10 . The knob 10 is pivotally affixed to the handle grip 12 via a rotating retaining-ring 60 that resides within grooves in both the knob and the handle grip 12 .
[0085] As illustrated in FIG. 10 , a catheter body-retaining nut 36 is threadably affixed to the distal end of a wire guide 26 that extends along the axial center of the knob 10 . As indicated in FIG. 10 and more clearly shown in FIG. 11 , which is a longitudinal sectional plan view of the knob 10 taken along section line BB in FIG. 9 , a cylindrical hole or shaft 60 passes through the knob 10 along the knob's longitudinal axis. The inner circumferential surface of the shaft 60 has both right hand threads 62 and left hand threads 64 that extend towards the distal end of the knob 10 from a hub portion 23 of the knob 10 . As shown in FIG. 11 , in one embodiment, the knob 10 is a singular integral piece.
[0086] As indicated in FIG. 10 , a right slide 30 and a left slide 32 are longitudinally displaceable within the handle 2 and about the proximal end of the wire guide 26 . As shown in FIGS. 12 and 13 , which are, respectively, aright side isometric view of the slides 30 , 32 displaced about the wire guide 26 and a left side isometric view of the slides 30 , 32 displaced about the wire guide 26 , each slide 30 , 32 has a planar slide face 48 that abuts and slideably displaces against the slide face 48 of the opposed slide 30 , 32 . Also, each slide 30 , 32 has a channel 40 that combines with the channel 40 of the opposed slide 30 , 32 to form a passage 40 through which the proximal end of the wire guide 26 passes as the slides 30 , 32 displace about the wire guide 26 . As shown in FIG. 10 , the passage 40 formed by the channels 40 also provides a pathway along which the deflection wires 38 a , 38 b (represented by dashed lines in FIG. 10 ) travel from a proximal portion of the slides 30 , 32 , through the wire guide 26 , and onward to the extreme distal end 14 of the catheter body 4 .
[0087] As indicated in FIGS. 12 and 13 , each slide 30 , 32 has a half-cylinder distal portion 46 and a shorter and wider half-cylinder proximal portion 47 . The right slide 30 has a right-handed thread 56 on its distal portion 46 . Similarly, the left slide 32 has a left-handed thread 58 on its distal portion 46 . Thus, as can be understood from FIG. 10 , when the knob 10 is rotated in a clockwise direction relative to the handle grip 12 , the right handed threads 62 within the knob 10 engage the right handed threads 56 of the right slide 30 , and the left handed threads 64 within the knob 10 engage the left handed threads 58 of the left slide 32 . As a result, the right slide 30 is distally displaced within the handle 2 and the left slide 32 is proximally displaced within the handle 2 . Accordingly, the deflection wire 38 a attached to the right slide 30 is pushed (i.e., subjected to a compressive force) and the deflection wire 38 b attached to the left slide 32 is pulled (i.e., subjected to a tension force). Conversely, if the knob is rotated counterclockwise, the opposite displacement of the slides 30 , 32 and deflection wires 38 a , 38 b will occur.
[0088] As indicated in FIG. 10 , each deflection wire 38 a , 38 b is attached to the proximal portion 47 of its respective slide 30 , 32 via retention screws 42 . The retention screws, which are more clearly illustrated in FIGS. 12 and 13 , are threadably mounted in the proximal portions 47 .
[0089] As shown in FIGS. 12 and 13 , each half-cylindrical proximal portion 47 of a slide 30 , 32 has an upper and lower planar notch 64 adjacent their respective planar slide faces 47 . The function of these notches 64 may be understood by referring to FIGS. 14 and 15 .
[0090] FIG. 14 is a longitudinal section elevation of the handle grip 12 taken along section line CC in FIG. 7 . FIG. 15 is a latitudinal section elevation of the handle grip 12 taken along section line DD in FIG. 8 . As shown in FIGS. 14 and 15 , the handle grip 12 is one integral piece having an interior cylindrical void 66 in which the proximal portions 47 of the slides 30 , 32 may displace as indicated in FIG. 10 .
[0091] As shown in FIGS. 14 and 15 , upper and lower ribs 68 extend from the walls that form the interior cylindrical void 66 . The ribs 68 run longitudinally along a substantial portion of the cylindrical void's length. As can be understood from FIGS. 12-15 , the upper planar notches 64 on the proximal portions 47 of the slides 30 , 32 interface with, and displace along, the upper rib 68 as the slides 30 , 32 displace within the cylindrical void 66 . Similarly, the lower planar notches 64 on the proximal portions 47 of the slides 30 , 32 interface with, and displace along, the lower rib 68 as the slides 30 , 32 displace within the cylindrical void 66 . Thus, the ribs 68 act as thrust surfaces for the slides 30 , 32 .
[0092] For a detailed discussion of another embodiment of the handle 2 depicted in FIGS. 7-15 , reference is now made to FIG. 16 . FIG. 16 is an isometric view of the distal end of a control handle 2 for a catheter 5 wherein the handle 2 and catheter body 4 have a through lumen 70 . As shown in FIG. 16 , in one embodiment, the lumen 70 and the electrical wire tube 6 , which extends to the electrical connector 8 , pass through strain reliefs 71 and into the proximal end of the handle grip 12 . In one embodiment, the lumen 70 terminates at its proximal end with a stopcock 72 . In one embodiment, the stopcock 72 has a hemostasis seal 74 that can be utilized for guide wire insertion. While a long flexible length of lumen 70 , as depicted in FIG. 16 , provides motion isolation while inserting contrast from a syringe, in one embodiment, the lumen 70 does not extend from the handle grip 12 . Instead, the stopcock 72 or luer fitting is simply attached to the lumen 70 where it exits the proximal end of the handle 12 .
[0093] For a better understanding of the path of the lumen 70 , reference is now made to FIGS. 17 , 18 and 19 . FIG. 17 is an isometric view of the slides 30 , 32 , the wire guide 26 , the wire tubing 6 , and the lumen 70 illustrating the path the lumen 70 takes through the handle 2 . FIG. 18 is an elevation view of the extreme proximal end surfaces of the slides 30 , 32 as viewed from arrow A in FIG. 17 and illustrating the path the lumen 70 and wire tubing 6 take into the passage 40 formed by the channels 40 of the slides 30 , 32 . FIG. 19 is an isometric view of the lumen 70 , deflection wires 38 a , 38 h , and electrical wires 76 of the wire tube 6 exiting the catheter body-retaining nut 36 on the distal end of the handle 2 .
[0094] As shown in FIGS. 17 and 18 , the lumen 70 and the wire tubing 6 pass through their respective reliefs 71 and into the passage 40 formed by the channels 40 in each slide 30 , 32 . In one embodiment, soon after the wire tubing 6 and the lumen 70 enter the passage 40 , the wires 76 of the wire tubing 6 exit the wire tubing 6 and are dispersed about the outer circumference of the lumen 70 as depicted in FIG. 19 .
[0095] As illustrated in FIG. 17 , in another embodiment, after the wire tube 6 and lumen 70 enter the passage 40 , the wire tube 6 and the lumen 70 continue on their pathway to the distal end 14 of the catheter body 4 by passing, in a side-by-side arrangement, through the remainder of the passage 40 formed into the slides 30 , 32 and into an internal passage that extends along the longitudinal axis of the wire guide 26 . Near the end of the wire guide 26 , the wire 76 exists the wire tube 6 . The wire 76 , lumen 70 and deflection wires 38 a , 38 b then pass into the catheter by exiting the catheter body-retaining nut 36 of the handle as indicated in FIG. 19 .
[0096] For a detailed discussion of another embodiment of the handle 2 , reference is now made to FIG. 20 , which is an isometric view of the handle 2 exploded to show its various components. As can be understood from FIG. 20 , the features of the handle 2 depicted in FIG. 20 are similar to the features of the handle depicted in FIG. 2 , except the handle 2 depicted in FIG. 20 is configured to have a relatively large, generally uniform in diameter, pathway extend the full length of the handle 2 (i.e., from the distal opening 102 in the wire guide 26 , through the passage 40 defined in the slides 30 , 32 and through an exit hole 104 in the proximal end of the shaft 16 ).
[0097] The configuration of the handle 2 that allows a relatively large generally uniform in diameter pathway to pass through the length of the handle 2 , as depicted in FIG. 20 , is more clearly shown in FIG. 21 , which is a longitudinal sectional elevation taken along section line ZZ in FIG. 20 . As illustrated in FIG. 21 , in one embodiment, the pathway 100 , which includes the passage through the wire guide 26 and the passage 40 through the slides 30 , 32 , is large enough that the catheter body 4 itself may pass through the pathway 100 and be connected to the proximal end of the shaft 16 at the exit hole 104 . Thus, in one embodiment, to prevent the catheter body 4 from rotating with the adjusting knob 10 , the catheter body 4 is affixed to the shaft 16 at the exit hole 104 . In one embodiment, the catheter body 4 runs the full length of the handle 4 as depicted in FIG. 21 , except the body 4 is affixed to the wire guide 26 at or near the distal opening 102 . In other embodiments, the catheter body 4 is affixed to both the wire guide 26 at or near the distal opening 102 and the shaft 16 at the exit hole 104 .
[0098] As can be understood from FIG. 21 and as more clearly depicted in FIG. 22 , which is isometric views of the slides 30 , 32 oriented to show their portions of the passage 40 and their planar slide faces 48 , the passage 40 is large enough in diameter to displace over the outer diameter of the wire guide 26 . As shown in FIGS. 21 and 22 , a catheter body passage 110 passes through the proximal portion 44 of each slide 30 , 32 , thereby allowing the slides 30 , 32 to displace back and forth over the outer surface of the catheter body 4 .
[0099] As indicated in FIG. 21 , in one embodiment, the catheter body 4 has an opening 111 in its wall that allows the wires 38 to exit the body 4 and connect to the slides 30 , 32 . In one embodiment, the wires 38 connect to the slides 30 , 32 via tension adjustment screws 54 as previously discussed.
[0100] Due to the configuration of the slides 30 , 32 , the wire guide 26 and the shaft 16 , the catheter body 4 may run uninterrupted the full length of the handle 2 . As a result, electrical wiring 76 (see FIG. 19 ) and a lumen 70 may be routed the full length of the handle 2 by way of the body 4 .
[0101] For a detailed discussion of another embodiment of the handle 2 of the present invention, reference is now made to FIGS. 23 and 24 . FIG. 23 is an isometric view of the handle 2 exploded to show its various components. FIG. 24 is a longitudinal sectional elevation of the handle 2 taken along section line YY of FIG. 23 . Generally speaking, the features of the handle 2 depicted in FIGS. 23 and 24 are similar to the features of the handle depicted in FIG. 20 , except the two embodiments employ different slider arrangements. For example, the embodiments depicted in FIGS. 1-22 employ parallel slides or members 30 , 32 (i.e., the slides 30 , 32 exist within the handle 2 in a parallel or side-by-side arrangement). As will be understood from FIGS. 23 and 24 and the following figures, in the embodiment of the handle 2 depicted in FIGS. 23 and 24 , the slides or members 150 , 152 exist within the adjustment knob 10 in a series arrangement (i.e., the slides 150 , 152 are not parallel or side-by-side to each other, but are oriented end-to-end along a longitudinal axis of the handle 2 ).
[0102] As shown in FIGS. 23 and 24 , the adjusting knob 10 is pivotally coupled to the distal end of the mounting shaft (i.e., base portion) 16 . The wire guide 26 extends through the center of the adjusting knob 10 and the mounting shaft 16 . The catheter body 4 is coupled to the distal end of the wire guide 26 and, in one embodiment, extends through the wire guide 26 and out of the proximal end of the mounting shaft 16 .
[0103] As shown in FIGS. 23 and 24 , a distal slide 150 is located in a distal portion of the adjusting knob 10 , and a proximal slide 152 is located in a proximal portion (i.e., hub portion 23 ) of the adjusting knob 10 . As illustrated in FIG. 24 , the outer surface of each slide 150 , 152 has threads 154 that mate with threads 156 on an interior surface of the adjusting knob 10 .
[0104] As illustrated in FIG. 24 , each deflection wire 38 a , 38 b travels along the interior of the wire guide 26 until it exits the wire guide 26 at a hole 157 in the sidewall of the wire guide 26 . Each deflection wire 38 a , 38 b then extends to the slide 150 , 152 to which the deflection wire 38 a , 38 b is attached. In one embodiment, in order to attach to a slide 150 , 152 , a deflection wire 38 a , 38 b passes through a passage 159 in the slide 150 , 152 and attaches to a hollow tension adjustment screw 54 via a knot 52 as previously described in this Detailed Description.
[0105] For a better understanding of the orientation of the threads 154 , 156 , reference is now made to FIGS. 25 and 26 . FIG. 25 is the same longitudinal sectional elevation of the adjusting knob 10 as it is depicted in FIG. 24 , except the adjusting knob 10 is shown by itself. FIG. 26 is a side elevation of the slides 150 , 152 .
[0106] As shown in FIGS. 25 and 26 , in one embodiment, the distal slide 150 has right hand threads 154 that engage right hand threads 156 in the distal portion of the adjusting knob 10 , and the proximal slide 152 has left hand threads 154 that engage left hand threads 156 in the proximal portion of the adjusting knob 10 . Thus, as can be understood from FIGS. 23-26 , when the adjusting knob 10 is rotated relative to the mounting shaft 16 in a first direction about the longitudinal axis of the handle 2 , the slides 150 , 152 will converge along the wire guide 26 , thereby causing the first wire 38 to be placed into tension and the second wire 38 to be compressed. As a result, the distal end 14 of the catheter body 4 will deflect in a first direction. Similarly, when the adjusting knob 10 is rotated in a second direction that is opposite from the first direction, the slides 150 , 152 will diverge along the wire guide 26 , thereby causing the first wire 38 to be compressed and the second wire 38 to be placed into tension. As a result, the distal end 14 of the catheter body 4 will deflect in a second direction generally opposite from the first direction.
[0107] In one embodiment, to prevent the slides 150 , 152 from simply rotating around the wire guide 26 when the adjusting knob 10 is rotated, the slides 150 , 152 and wire guide 26 are configured such that the slides 150 , 152 will displace along the wire guide 26 , but not rotationally around it. For example, as indicated in FIG. 27A , which is a latitudinal sectional elevation of the handle 2 as taken along section line XX in FIG. 24 , the wire guide 26 has a square cross section that mates with a square hole 162 running the length of the slide 150 , 152 . The interaction between the square hole 162 and the square cross section of the wire guide 26 prevents a slide 150 , 152 from rotating about the wire guide 26 , but still allows the slide 150 , 152 to displace along the length of the wire guide 26 .
[0108] In another embodiment, as shown in FIG. 27B , which is the same latitudinal sectional elevation depicted in FIG. 27A , each slide 150 , 152 has a hole 162 with a circular cross section. Each hole 162 runs the length of its respective slide 150 , 152 and includes a key 160 that extends into the hole 162 from the interior circumferential surface of the hole 160 . The key 160 engages a groove or slot 158 that runs along the length of the wire guide 26 as depicted in FIG. 28 , which is a side elevation of one embodiment of the wire guide 26 . The interaction between the key 160 and the slot 158 prevents a slide 150 , 152 from rotating about the wire guide 26 , but still allows the slide 150 , 152 to displace along the length of the wire guide 26 .
[0109] As shown in FIGS. 27A and 27B , a hollow shaft 165 extends through the wire guide 26 . This allows a catheter body 4 with a lumen to extend completely through the handle 2 as shown in FIG. 24 .
[0110] For a detailed discussion of another embodiment of the handle 2 that is similar to the embodiment depicted in FIG. 23 , reference is now made to FIGS. 29 and 30 . FIG. 29 is a longitudinal sectional elevation of the handle 2 as if taken through section line YY of FIG. 23 . FIG. 30 is a longitudinal sectional plan view of the handle 2 as if taken through section line VV in FIG. 23 and wherein section line VV forms a plane that is perpendicular to the plane formed by section line YY in FIG. 23 .
[0111] As illustrated in FIGS. 29 and 30 , the handle 2 includes an adjusting knob 10 pivotally coupled to the distal end of the mounting shaft (i.e., base portion) 16 . In one embodiment, the adjusting knob 10 includes a proximal end 170 , a distal end 172 and a threaded shaft 173 , which is connected to the proximal end 170 and extends distally along the longitudinal axis of the adjusting knob 10 . The threaded shaft 173 includes a distal end 174 , a proximal end 176 , a series of right hand threads 178 along a distal portion of the shaft 173 , and a series of left hand threads 180 along a proximal portion of the shaft 173 .
[0112] As shown in FIGS. 29 and 30 , a distal slide 150 is located in a distal portion of the adjusting knob 10 , and a proximal slide 152 is located in a proximal portion (i.e., hub portion 23 ) of the adjusting knob 10 . Each slide has a hole 155 through which the threaded shaft 173 passes. The inner circumferential surface of the hole 155 for the distal slide 150 has right hand threads that mate with the right hand threads 178 on the distal portion of the shaft 173 . Similarly, the inner circumferential surface of the hole 155 for the proximal slide 152 has left hand threads that mate with the left hand threads 180 on the proximal portion of the shaft 173 . In other embodiments, the locations for the left and right threads are reversed.
[0113] As can be understood from FIGS. 29 , 30 and 31 , which is an isometric view of one embodiment of the wire guide 26 , a hollow center shaft 182 extends from the distal end of the wire guide 26 , through the threaded shaft 173 of the adjustment knob 10 , and to the proximal end of the base shaft 16 . Thus, in one embodiment, a catheter body 4 may be routed through the lumen 165 of the wire guide's hollow center shaft 182 to exit the proximal end of the handle 2 , as illustrated in FIGS. 29 and 30 .
[0114] As illustrated in FIG. 29 , each deflection wire 38 a , 386 travels along the interior of the wire guide 26 until it exits the wire guide 26 at a hole 157 in the sidewall of the wire guide 26 . Each deflection wire 38 a , 38 b then extends to the slide 150 , 152 to which the deflection wire 38 a , 38 h is attached. In one embodiment, in order to attach to a slide 150 , 152 , a deflection wire 38 a , 38 b passes through a passage 159 in the slide 150 , 152 and attaches to a hollow tension adjustment screw 54 via a knot 52 as previously described in this Detailed Description.
[0115] In one embodiment, as shown in FIG. 29 , the deflection wire 38 b leading to the proximal slide 152 passes through a second passage 161 in the distal slide 150 . The second passage 161 has sufficient clearance that the passage 161 may easily displace along the wire 38 b when the distal slide 150 displaces distally and proximally. The second passage 161 serves as a guide that stiffens the wire 38 b and helps to reduce the likelihood that the wire 38 b will bend when compressed.
[0116] As can be understood from FIGS. 29 and 30 , when the adjusting knob 10 is rotated relative to the mounting shaft 16 in a first direction about the longitudinal axis of the handle 2 , the slides 150 , 152 will converge along the threaded shaft 173 , thereby causing the first wire 38 a to be placed into tension and the second wire 38 b to be compressed. As a result, the distal end 14 of the catheter body 4 will deflect in a first direction. Similarly, when the adjusting knob 10 is rotated in a second direction that is opposite from the first direction, the slides 150 , 152 will diverge along the threaded shaft 173 , thereby causing the first wire 38 a to be compressed and the second wire 38 b to be placed into tension. As a result, the distal end 14 of the catheter body 4 will deflect in a second direction generally opposite from the first direction.
[0117] In one embodiment, to prevent the slides 150 , 152 from simply rotating with the threaded shaft 173 within the adjusting knob 10 when the adjusting knob 10 is rotated, the slides 150 , 152 and wire guide 26 are configured such that the slides 150 , 152 will displace along the threaded shaft 173 , but not rotationally within the adjusting knob 10 . For example, as indicated in FIGS. 31 and 32 , which is a latitudinal sectional elevation of the handle 2 as taken along section line WW in FIG. 29 , the wire guide 26 has right and left semicircular portions 190 that oppose each other and extend along the length of the hollow center shaft 182 of the wire guide 26 . As shown in FIG. 32 , the generally planar opposed faces 192 of the semicircular portions 190 abut against the generally planar side faces 194 of the slides 150 , 152 . This interaction prevents a slide 150 , 152 from rotating within the adjustment knob 10 when the knob 10 is rotated, but still allows the slide 150 , 152 to displace along the length of the threaded shaft 173 .
[0118] As can be understood from FIG. 36 , which is a diagrammatic illustration of the control handle 2 of the subject invention being employed in a surgical procedure on a patient 200 , the distal end 14 of the catheter body 4 is inserted into the patient 200 (e.g., intravenously via a body lumen 202 of the patient 200 , percutaneously, or via other avenues for entering the patient's body). The distal end 14 of the catheter body 4 is advanced until positioned in a selected location within the patient 200 (e.g., within a chamber 204 of the patient's heart 206 or other organ, with a body cavity of the patient, etc.). The distal end of the catheter body 4 is then deflected by rotating the adjustment knob 10 about a longitudinal axis of a base portion 16 . As can be understood from FIGS. 1-35 , this causes the slides 30 , 32 within the handle 2 to displace along the longitudinal axis in opposite directions. Since each slide 30 , 32 is coupled to its respective deflection wire 38 and each deflection wire 38 runs through the catheter body 4 and is coupled to the distal end 14 , the distal end 14 of the catheter body 4 is deflected.
[0119] Although a number of embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. For example, all joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative, only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.
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An apparatus for imparting a tensile force to deflect a distal portion of a catheter while maintaining its exterior dimensions may include a handle grip including a cross-section of generally predetermined exterior dimensions, and a longitudinal axis. A flexible elongate member may include proximal and distal end portions, with the proximal end portion being coupled to the handle grip. An adjustment knob may include a cross-section of generally predetermined exterior dimensions, and is rotatably coupled to the handle grip around the longitudinal axis. An elongate deflection member may be operably coupled to the adjustment knob and to the distal end portion of the elongate member. Rotation of the adjustment knob may impart a tensile force to the deflection member thereby causing the distal end portion of the elongate member to deflect from a prior configuration while maintaining the generally predetermined exterior dimensions of the handle grip and the adjustment knob.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] The present invention relates generally to an apparatus and method for inserting and retrieving pipeline pigs into pipelines, and more specifically to an apparatus and method for installing an in-line piggable wye fitting into a pipeline for the insertion and removal of in-line inspections tools.
[0005] The primary purpose of pipeline pigs is to clean and obtain vital information concerning the integrity of the pipeline. The pigs used in most oil and liquid products pipelines are typically used to remove paraffins, sludge, and water from the pipeline. The most common pigs that are used in oil and liquid products pipelines are in the shape of spheres or bullets that are made of a polyurethane material. As a result, these foam pigs are lightweight, easy to work with, and able to negotiate uncommon piping, fittings, and valves. Other types of cleaning pigs are solid cast pigs and steel mandrel scraper pigs. In other applications, such as oil and gas and natural gas pipelines, intelligent pigs (also called in-line inspection (ILI) tools) are used to determine the integrity of the pipe wall for such conditions as corrosion, wall thinning, and other defects that may affect the pipeline operations. Common types of these intelligent pigs include ultrasonic (UT) and magnetic flux leakage (MFL) induced sensors, such as the SmartScan sensors made by GE and many others well known in the art.
[0006] A pig must be launched into the pipeline for cleaning or inspection (typically by a launching station) and removed from the pipeline (typically by a receiving station) to allow for normal operation of the pipeline when the pig is in the pipeline. The pig is typically introduced into the pipeline by means of a bypass loop that diverts the flow of the pipeline product to the launch vessel by the use of valves and other pipeworks. When the pipeline product is diverted to the launcher, a valve downstream of the launcher is opened and the pig is introduced into the pipeline by means of the launching station. In most cases, the tool travels along the length of the pipeline with special seals that allow the product flowing in the pipeline to push the tool. As the tool travels, it cleans the pipeline and/or performs inspections on the pipeline and is received into the receiving vessel at the end of the pipeline run. The receiver is similar to the launcher in that a bypass loop is established with valving and pipeworks to divert the tool into the receiver without substantially disrupting the pipeline operations. In most oil and liquid products pipelines, launch and receive stations are permanently installed at various locations during installation of the pipelines to allow the cleaning of paraffin deposits and other mineral build-ups. Because the valving and pipeworks of these pipeline systems were designed for the use of pigs (i.e., the valves in these pipelines typically include an orifice the same size as the internal pipeline and consistently sized piping was used between launch and receive stations), the pigs are able to inspect a long length of pipeline between the launch and receive stations.
[0007] The most comprehensive method to give an overall assessment of a natural gas and crude pipeline is to run intelligent pigs that can map many inspection points along the internal length of the pipeline. The challenge in using intelligent pigs in these pipelines is the piping configurations that prevented previous technologies from gathering the required information on a cost effective basis, often called “unpiggable” pipelines. Pipelines can be “unpiggable” for a variety of reasons, including changes in diameter (because of compressibility of gas, the use of multi-diameter pipes is common), presence of unsuitable valves, tight or mitered bends (less than three diameters), low operating pressure, low flow or absence of flow, lack of launching and receiving facilities, dented or collapsed areas, and excessive debris or scale build-up. Natural gas pipelines are particularly known for having a high number of “unpiggable” pipelines. Further, in natural gas pipelines, products rarely produced deposits onto the pipe walls and did not require cleaning during the service life of the pipelines. Thus, the use of pipeline cleaning or in-line inspection pigs, and the use and installation of launch and receive stations, were traditionally not common in natural gas pipelines. Rather, the integrity of the pipeline was monitored by various means such as by using sacrificial corrosion coupons (e.g., pipe samples taken from the pipeline wall), visual inspection, and/or digs to perform pipe wall thickness analyses to predict corrosion rates. Unfortunately, these methods are only indicative of the conditions at the specific spots of inspection.
[0008] Techniques were developed for a method and system that uses “hot tap” technology to access the existing pipeline by adding a new connection to the pipeline without interruption of service. In this technique, after a 45 degree hot tap is made in the pipeline, a chute housing is connected to the hot tap valve. The chute within the housing is inserted through the hot tap valve to provide a path for the inspection tool to follow into the pipeline. After the chute is inserted, the bypass piping with the launch vessel is assembled to the pipeline and chute housing, and gas is allowed to flow from the pipeline so as to enter behind the inspection tool. The mainline valve is closed and the bypass valve is opened launching the tool into the pipeline. The inspection tool proceeds through the pipeline performing pipeline integrity tests and then is removed from the pipeline when it enters into the receiver station that is substantially similar to the launch station. At both the launching and receiving sites, the chute is retracted and the chute housing and associated pipeworks are removed prior to insertion of the completion plugs. The completion plugs are set to allow the hot tap valves to be removed. Once the completion plug is set, a blind flange is installed and the pipeline can be covered. A similar system is described in WO 2005/119117, incorporated herein by reference.
[0009] Although this “hot tap” method has been used in industry, it suffers from numerous and significant disadvantages. The complexity of the hot tap technique for insertion of launch and receive vessels to be connected to chute housings requires customization for every application. Another primary disadvantage is that the equipment for introducing and retrieving an inspection tool into and from a pipeline by the hot tap method are extremely large and heavy. The chute housings with the actuators can extend over 50 feet above the pipeline requiring considerable lifting capabilities as well as supports for the equipment. Using this equipment requires detailed planning for transportation, assembly, and use, such as acquiring right of ways for transportation of the equipment to the work site. Additionally, the equipment is limited in application due to the complexity of the tool geometry, which lends itself to larger diameter pipelines, so inspection tools typically cannot not be inserted into smaller diameter pipelines according to this “hot tap” method. Another problem is the high cost for the use of such chute housings and launch and receive vessels and associated methods for use and installation. Typical launch/receive stations (including the chute housings) for this “hot tap” method require a large investment in piping and facilities with little payback, and often run into the millions of dollars per station. As a result, many pipelines cannot be efficiently and/or effectively inspected, if even inspected at all.
[0010] What is needed is an apparatus and method for inserting a pig or inline inspection tool into a pipeline that will simplify the design, installation, and operation of fittings and associated pipeworks for launching/receiving inspection tools, reduce installation time of such equipment, reduce the equipment size, allow for temporary launch/receive facilities, reduce capital and operating costs, allow for inspection of previously unpiggable pipes (such as smaller diameter pipelines), and allow for more frequent and easier insertion and removal of tools into the pipeline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates a preferred embodiment of the present invention including an exterior view of the in-line piggable wye fitting.
[0012] FIG. 2A illustrates a cross-sectional side view of the piggable wye fitting shown in FIG. 1 with the guide withdrawn from the pipeline.
[0013] FIG. 2B illustrates a cross-sectional side view of the piggable wye fitting shown in FIG. 1 with the guide extended into the pipeline.
[0014] FIG. 3 illustrates a preferred embodiment of the piggable wye fitting shown in FIG. 1 connected to a pipeline with a launch vessel and temporary valving.
[0015] FIG. 4 illustrates a preferred embodiment of the piggable wye fitting shown in FIG. 1 connected to a pipeline without a launch vessel and temporary valving.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring to FIG. 1 , a preferred embodiment of the present invention is illustrated. FIG. 1 shows an in-line piggable wye fitting 2 , including sweep piping 4 , pup piping 6 , wye body 1 , and flange 12 attached to an extended branch of sweep piping 4 that is inset into wye body 1 (the inset being shown in more detail in FIGS. 2-3 ). Piggable wye fitting 2 allows the insertion and retrieval of a pig or inspection tool into a pipeline. Pup piping 6 (a first fitting portion of wye fitting 2 ) is preferably the same diameter and material as the pipeline to which pup piping 6 is connected and is substantially straight and parallel to the pipeline to which it is connected so as to not impede flow in the pipeline during normal operation. Indeed, pup piping 6 can alternatively be the pipeline itself. Pup piping 6 connects piggable wye fitting 2 and the launch/receive vessel (not shown) to the pipeline by means of welding and/or flanged ends. The piggable wye fitting 2 in combination with a launch or receive vessel and corresponding pipeworks is generally termed a launch or receiving station.
[0017] As indicated, in one embodiment pup piping 6 is preferably connected to the pipeline by welding or flanging each end of pup piping 6 directly in-line to the pipeline. Thus, a first end of pup piping 6 may be connected to a first end of the pipeline, and a second end of pup piping 6 may be connected to a second end of the pipeline to permit normal operation of the pipeline through wye body 1 and pup piping 6 . This portion of wye body 1 between the first and second ends of pup piping 6 is referred to as the run portion of wye body 1 . Sweep piping 4 (a second fitting portion of wye fitting 2 ) is inset into wye body 1 and connects wye fitting 2 to launch or receive facilities through flange 12 . In a preferred embodiment, wye body 1 is a cast body, to which flange 26 is bolted and sweep piping 4 is inset.
[0018] In a preferred embodiment, sweep piping 4 is the same diameter and material as the pipeline to which pup piping 6 is connected. Guide feed 8 (shown in FIGS. 2A and 2B ) extends and withdraws guide 32 (shown in FIGS. 2A and 2B ) into and out of the run portion of wye body 1 in order to divert the pipeflow into sweep piping 4 and the inspection tool into or out of the launch or receive vessels. Depending on the directional flow of fluid in this portion of wye body 1 , the orientation of wye fitting 2 as shown in FIG. 1 can be connected to either the launching vessel or the receiving vessel.
[0019] In a preferred embodiment, wye fitting 2 has a radial sweep of three pipe diameters as measured between pup piping 6 and sweep piping 4 . Such a radial sweep allows current technology inspection tools (that often have multi-units forming a train of sensing hardware) to more easily navigate into and out of the pipeline. In this embodiment, the wye body 1 is made, or cast, with a predetermined angle (identified as angle A in FIGS. 2A and 2B ) with a radius of three times the nominal line size to allow for the inspection tool to enter and exit the pipeline, such as approximately a 45 degree angle.
[0020] Referring to FIGS. 2A and 2B , a preferred embodiment of the present invention is illustrated showing cross-sectional side views of piggable wye fitting 2 with guide 32 withdrawn from ( FIG. 2A ) and extended into ( FIG. 2B ) the run portion of wye body 1 . Piggable wye fitting 2 as illustrated in FIGS. 2A and 2B includes sweep piping 4 , pup piping 6 , guide feed 8 , wye body 1 , and guide assembly 10 . In a preferred embodiment, guide feed 8 includes feedscrew shaft 22 , feednut 24 , gasketed plate 26 , and packing gland 28 . In this embodiment, the housing of guide feed 8 is cast wye body 1 , as shown in FIG. 1 . The top of guide feed 8 is enclosed by gasketed plate 26 that is bolted to wye body 1 . Feedscrew shaft 22 can be rotated (by way of a rotator attached to feedscrew shaft 22 ) counter-clockwise a predetermined amount of turns until the guide is completely withdrawn into the fitting housing of guide feed 8 so as to not impede pipe flow, or conversely rotated clockwise for extension into what is effectively an extension of pup piping 6 .
[0021] A few examples of such a rotator include a handle or wheel, which can be attached to a portion of feedscrew shaft 22 that extends through gasketed plate 26 . An indicator 5 can be located on the outer feedscrew extension that shows how deep the guide is placed into the pipeline. Packing gland 28 encases elastomeric seals in gasketed plate 26 and against feedscrew shaft 22 . Guide feed 8 is connected to guide assembly 10 by a feed attachment such as feednut 24 , which is preferably attached to guide assembly 10 by screws and is preferably made of a brass alloy to aid in lubrication and ensure an even actuation of guide feed 8 . Guide assembly 10 includes guide 32 , guide support 34 , and guide extender 36 . Guide 32 is extended into the run portion of wye body 1 by guide feed 8 to divert the pipeflow into sweep piping 4 and an inspection tool into or out of the launch or receive vessels and the pipeline. Guide 32 is attached to guide extender 36 , which is connected to feednut 24 . In one embodiment, guide extender 36 is rolled plate that conforms to the outside diameter of the sweep piping 4 . Guide support 34 is attached to the bottom of guide 32 to provide support and a positive stop of guide 32 at the bottom of the pipeline wall of pup piping 6 .
[0022] It will be apparent to one of ordinary skill in the art that the specifications of wye fitting 2 can be modified for insertion or extraction of an inspection tool into a pipeline depending on the particular situation. For example, the neck of sweep piping 4 and feedscrew 22 can be extended to allow for operation of the wye fitting above ground level that does not require excavation during use. In another embodiment, rather than using a feedscrew to position a guide into the pipeline, a swing check can be utilized that retracts and extends guide assembly 10 into the pipeline.
[0023] FIG. 3 illustrates a preferred embodiment of the piggable wye fitting shown in FIG. 1 connected to a launch vessel and corresponding pipeworks to allow for normal operation of the wye fitting. As depicted in FIG. 3 , the orientation of wye fitting 2 along with flow F of pipeline fluid indicates that the wye fitting is to be utilized in a launching station for the introduction of an inspection tool or pig into the pipeline. It will be apparent to one of ordinary skill in the art that the orientation depicted in FIG. 3 can be reversed to utilize the piggable wye fitting in a receiving station setup. It will also be apparent to one of ordinary skill in the art how the arrangement and operation of the launching/receiving vessels and valves and other associated pipeworks operate in conjunction with the piggable wye fitting.
[0024] As shown in FIG. 3 , in-line piggable wye fitting 2 is installed on pipeline 44 and connected to launch vessel 42 . Mainline valve 54 is connected to pipeline 44 and exists on the pipeline upstream of piggable wye fitting 2 . Bypass valve 56 is connected to pipeline 44 via bypass flange 13 and launch vessel 42 and exists on pipeline 44 upstream of piggable wye fitting 2 and mainline valve 54 . It will be apparent to one of ordinary skill in the art that launch vessel 42 can be a common launching vessel for the introduction of pigs or in-line inspections tools into a pipeline, and that its specifications may vary depending upon the requirements of the pipeline, pipeline fluid, and/or inspection tool. Full port ball valve 52 is connected on one end to flange 12 of wye fitting 2 and on the other end to launch vessel 42 . In a preferred embodiment, wye fitting 2 stays permanently connected to pipeline 44 during normal operation of the pipeline by keeping the guide withdrawn from the pipeline so as to not impede pipeline flow. Before an inspection tool has been inserted into the pipeline (or after an inspection tool has been utilized and removed from the pipeline), launch vessel 42 , full port ball valve 52 , and bypass valve 56 are not needed for normal operation of the pipeline and can be removed from the piping configuration (as shown in FIG. 4 ). In this situation, flange 12 of wye fitting 2 and bypass valve flange 13 are temporarily capped until the launch vessel and corresponding valves and pipeworks need to be re-assembled for insertion or retrieval of the inspection tool.
[0025] In another preferred embodiment, a method is used to directly insert and retrieve an inspection tool into a pipeline according to the following procedure. In operation, and after a piggable wye fitting 2 and necessary pipeworks has already been connected to a pipeline using procedures described above and well known to those of ordinary skill in the art, full port ball valve 52 is bolted to flange 12 . A completion plug setter is removed through valve 52 , valve 52 is closed, and the completion plug setter is bled down of internal pressure. Launch vessel 42 , bypass valve 56 , and other pipeworks are connected to pipeline 44 and full port ball valve 52 using procedures well known to those of ordinary skill in the art. A similar operation is repeated downstream at an equivalent receiving station. After the inspection tool is assembled in launch vessel 42 , and with bypass valve 56 and full port ball valve 52 opened according to procedures well known to those of ordinary skill in the art, mainline valve 54 is slowly closed, reducing flow in the pipeline at guide 32 . Once the flow has been diverted, guide 32 is linearly actuated into the pipeline by rotating feedscrew 22 clockwise a predetermined number of turns until guide support 34 rests on the bottom of the inside pipe wall of pup piping 6 . The guide is at this point set and able to steer the pig or inspection tool into the main pipeline. The tool is allowed to travel through the pipeline and inspect the pipeline according to procedures well known in the art.
[0026] A similar installation and operation procedure is repeated at the receiving station to allow the inspection tool to exit the main pipeline through a second piggable wye fitting into a receiving vessel. When the inspection tool is received into the receive vessel, the pipeline can be restored to normal operation and the guide can be withdrawn from the pipeline by rotating the feedscrew counter-clockwise a predetermined amount of turns until the guide is completely withdrawn so as to not impede pipeline flow.
[0027] In another preferred embodiment, a method is used to insert the piggable wye fitting into an existing and operational line according to the following procedure. Line stops are installed near the proximity of the location where piggable wye fitting is to be installed. A bypass loop around the insertion point of the piggable wye fitting can be established through the line stops. The piping between the line stops is de-pressurized, the necessary amount of pipeline between the line stops is removed, and a piggable wye fitting is installed in the removed portion of the pipeline by welding the ends of the piggable wye fitting pup piping to the ends of the pipeline. The mainline pipe is pressured between the line stops and the line stops are removed. Completion plugs are installed at all necessary locations and the site is returned to normal conditions. An inspection tool can be inserted into and retrieved from the pipeline according to the procedures described above.
[0028] It will be apparent to one of skill in the art that described herein is a novel apparatus and method for inserting and retrieving an in-line inspection tool into a pipeline by the use of an in-line piggable wye fitting. While the invention has been described with references to specific preferred and exemplary embodiments, it is not limited to these embodiments. For example, it will be apparent to one of skill in the art that the piggable wye fitting can be installed in new construction or as a retrofit to an existing pipeline. The invention may be modified or varied in many ways and such modifications and variations as would be obvious to one of skill in the art are within the scope and spirit of the invention and are included within the scope of the following claims.
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A fitting for inserting a pig into a pipeline. The fitting comprises a cast body having a first end for connecting to a first end of a pipeline and a second end for connecting to a second end of the pipeline. The cast body further comprises a third end arranged at a predetermined angle to the first and second end of the cast body. A retractable guide within the cast body can be at least partially inserted into a run portion of the cast body for delivery or retrieval of the pig.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Under 35 U.S.C. 120, this application is a divisional application and claims priority to U.S. application Ser. No. 11/314,033, filed Dec. 20, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates generally to combs and scissors and more specifically to a combination comb and scissor tool.
BACKGROUND OF THE INVENTION
[0003] Many scissors and combs available today for hair styling are not flexible in positioning in respect to the handle, and do not have replaceable comb scissors and heads. Moreover, when such combs and scissors are used, the user first has to equalize the distance of the hair from the head by measuring it with a comb, then put the comb down and pick up scissors to trim the hair. These actions must be performed repeatedly to equalize and cut the hair, thus contributing to user fatigue, often causing carpal tunnel syndrome, and requiring additional time to go through the repeated movements.
[0004] Accordingly, what is needed is a system and method for reducing the number of repetitive movements needed first to equalize the length of the hair to be cut, and then to cut the hair, thereby minimizing user fatigue, minimizing the risk of contracting carpal tunnel syndrome, and reducing the time needed for completing a haircut. The present invention addresses such a need.
SUMMARY OF THE INVENTION
[0005] A tool comprising a scissors, the scissors including two handles, each handle including an aperture therethrough is disclosed. The tool includes a comb attached to the scissors. The comb includes a handle portion and a comb portion. The handle portion of the comb includes a plurality of extensions therefrom, the extensions for engaging the aperture of one of the handles of the scissors, wherein the comb can be removed from the scissors by disengaging the extensions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a first embodiment of the present invention.
[0007] FIG. 2 shows the clip-on comb in accordance with the present invention with extensions on its handle in more detail.
[0008] FIG. 3 is a photograph showing measurement of the length of hair to be cut utilizing the comb in accordance with the present invention.
[0009] FIG. 4 is a photograph showing cutting of the hair utilizing the comb in accordance with the present invention.
[0010] FIG. 5 illustrates a second embodiment of the present invention, comprising a mechanized comb-scissors device/tool/mechanism with a lever.
[0011] FIG. 6 illustrates the measurement or equalization of hair to be cut.
[0012] FIG. 7 shows the operation of the second embodiment of the present invention.
[0013] FIG. 8 illustrates an inner cam located inside the handle in the second embodiment of the present invention.
[0014] FIG. 9 illustrates a third embodiment of the present invention, comprising a mechanized comb-scissors device with a thumb tab.
DETAILED DESCRIPTION
[0015] The present invention relates generally to combs and scissors and more specifically to a combination comb and scissor tool.
[0016] The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiments and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein.
[0017] FIG. 1 shows a first embodiment of the present invention, comprising a comb 10 which clips onto one of the apertures (finger holes) 18 a and 18 b of a pair of scissors 12 . The scissors 12 comprise handle portions 20 a and 20 b and blade portions 22 a and 22 b. The handle portions 20 a and 20 b include apertures 18 a and 18 b, one of which through which the user's finger (not shown) is inserted, depending upon whether the user is left or right handed. The comb 10 comprises a comb portion 26 , a handle portion 24 , and has a plurality of extensions 14 a - 14 c on its handle 24 which clip onto one of the handles 16 a and 16 b of the scissors 12 through the apertures 18 a and 18 b one of which into which the user's finger (not shown) is inserted.
[0018] FIG. 2 shows the clip-on comb 10 in accordance with the present invention with extensions 14 a ′- 14 c ′ on its handle 24 in more detail. The handle 24 comprises a circular-like portion 202 with raised pads 14 a ′- 14 c ′ thereon. The clip-on comb 10 may be utilized by either a person who is left-handed or a person who is right-handed, since the extensions 14 a ′- 14 c ′ shown in FIGS. 1 and 2 allow the comb 10 to be attached to either side of the scissors (not shown).
[0019] FIG. 3 is a photograph showing measurement of the length of hair to be cut utilizing the comb in accordance with the present invention. When the comb 10 in accordance with the present invention is clipped onto the scissors 12 using the extensions 14 a - c on its handle as described in FIGS. 1 and 2 , the user first measures or equalizes the length of the hair to be cut and then positions the hair with the comb 10 . In this way the hair is prepared to be cut.
[0020] FIG. 4 is a photograph showing cutting of the hair utilizing the comb in accordance with the present invention. After the hair length to be cut is measured, as shown in FIG. 3 , the user then moves the comb 10 out of the way or to the side, and cuts the hair with the scissors 12 , as shown in FIG. 4 .
[0021] By utilizing the clip-on comb 10 and scissors 12 combination to cut hair, as shown in FIGS. 3 and 4 , time is saved since the user does not need to use a second hand to operate a pair of scissors while holding the comb with the first hand to equalize the length of the hair to be cut and also position the hair.
[0022] FIG. 5 illustrates a second embodiment of the present invention, comprising a mechanized comb-scissors device 500 with a lever 504 . The device 500 comprises a handle portion 502 , a lever 504 with an opening for a finger, a comb 506 and a scissors cutting blade(s) 508 .
[0023] In order to cut hair using the device 500 , the user first measures or equalizes the length of hair to be cut, as shown in FIG. 6 . Referring to FIG. 7 , the back-and-forth movement of the lever (not shown) causes a scissors blade(s) 508 to move in such a way as to cut the hair which is being held and positioned by the comb 506 , thereby accomplishing both positioning and “equalizing” the length of the hair to be cut via the comb 506 and then cutting the hair with the scissors 508 .
[0024] FIG. 8 illustrates an inner cam 702 located inside the handle 502 ′ which links the scissors blade(s) 508 ′ to the lever 504 ′, causing the scissors blade(s) 508 ′ to move up and down to cut the hair as the user moves the lever 504 ′ back and forth with their finger.
[0025] FIG. 9 illustrates a third embodiment of the present invention, comprising a mechanized comb-scissors device 900 with a thumb tab 904 . The device 900 comprises a handle portion 902 , a thumb tab 904 , a comb 906 and a scissors cutting blade(s) 908 . In this embodiment, the user moves the thumb tab 904 back and forth, thereby causing the scissors cutting blade(s) 908 to move up and down to cut the hair which is being positioned and measured to an “equalized” length by the comb 906 .
[0026] A person skilled in the art can see that other means by which a user causes the scissors cutting blade(s) to move up and down in combination with a comb to cut the hair would also be within the scope of the present invention.
[0027] Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.
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A tool comprising a scissors, the scissors including two handles, each handle including an aperture therethrough is disclosed. The tool includes a comb attached to the scissors. The comb includes a handle portion and a comb portion. The handle portion of the comb includes a plurality of extensions therefrom, the extensions for engaging the aperture of one of the handles of the scissors, wherein the comb can be removed from the scissors by disengaging the extensions.
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CROSS-REFERENCES TO RELATED APPLICATIONS
U.S. patent application Ser. Nos. 525,910, filed Aug. 24, 1983 .Iadd.now U.S. Pat. No. 4,649,526 .Iaddend.by Winbow and Baker; U.S. Ser. No. 440,140, filed Nov. 8, 1982 .Iadd.now abandoned .Iaddend.by Winbow, et al.; U.S. Ser. No. 395,449, filed July 6, 1982 .Iadd.now U.S. Pat. No. 4,606,014 .Iaddend.by Winbow and Chen; and U.S. Ser. No. 379,684 filed May 19, 1982 .Iadd.now U.S. Pat. No. 4,932,003 .Iaddend.by Winbow, et al.; all assigned to Exxon Production Research Company, relate to the general field of this invention.
BACKGROUND OF THE INVENTION
This invention relates to acoustic well logging in general and more particularly to methods and apparatus for generating and detecting acoustic waves in a formation, particularly of the acoustic shear wave type.
It has long been known in the investigation of subsurface earth formations traversed by a borehole that measurements or "logs" of acoustic energy introduced into the formation can yield extremely useful information about various formation parameters and characteristics. Accordingly, it has been conventional to introduce a logging sonde into the borehole containing some form of acoustic wave generator and receiver, to direct acoustic energy from the generator into the formation adjacent the borehole elevation of interest, and to thereafter record with the receiver the resultant acoustic waves returning from the formation.
One acoustic wave of particular interest is known in the art as the "shear" or "S" wave, which may develop in a formation as a result of vibratory motion in the formation at right angles to the direction of travel of the wave. A general discussion of this and related "compressional" (or "pressure") wave phenomena may be found in "The Full Acoustic Wave Train In A Laboratory Model Of A Borehole" by S. T. Chen, Geophysics, Volume 47, No. 11, November 1982, and in the aforementioned patent applications, all of which are herewith incorporated by reference for all purposes.
Shear wave logging has become increasingly useful in the detection of formation fractures as well as in determination of lithological properties of formations and the like. However, several problems have contributed to the difficulty in successful usage of this technique.
For example, often it has been found that the amplitude of the shear wave is insufficient for effective processing and analysis. Typically, the shear wave requires a greater travel time than the compressional wave to traverse the longitudinal distance through the formation between the acoustic generator and the detector. Accordingly, it was often found difficult to discriminate between this first-arriving compressional wave and the later-arriving shear wave (which may arrive before the compressional wave has completely attenuated.
Attempts were made to increase the magnitude of the S wave impinging upon the formation in order to increase the magnitude of the received S wave relative to the other signals, thereby increasing the signal to noise ratio. Such research produced some useful results, such as the realization that the angle at which the acoustic energy was introduced into the formation could enhance the formation of S waves, and the further discovery that multipole acoustic sources, such as quadrupole sources (discussed in aforementioned U.S. patent application Ser. No. 379,684), could more effectively produce desired S waves and provide a means for direct S-wave logging. The expression "multipole source" is used herein to denote sources of dipole, quadropole or higher order acoustic waves; but not to denote axially symmetric monopole sources.
However, severe problems still remained in the successful production of such S waves. For example, it has been known that multipole sources are less efficient acoustic radiators than are monopole sources. Accordingly, to obtain the benefits of multipole sources for direct S-wave logging, with improved signal to noise ratios over the compressional wave "noise" and other noise, more powerful multipole order sources were required.
Several design constraints were presented which hampered the creation of more powerful S wave sources. In particular, for conducting acoustic S-wave logging operations in soft formations it was often necessary to provide strong sources of S waves having frequencies less than three KHz. This, in turn, generally suggested physically large sources to obtain the necessary low resonant frequencies. However, use of large high-voltage source power supplies to energize such physically large sources was disadvantageous due to the attendant need for complicated electric circuit design and due to high voltage noise interference problems associated with such high voltage noise interference problems associated with such high voltage supplies.
SUMMARY OF THE INVENTION
The method and apparatus of the present invention are for the generation and transmission of acoustic waves into a subsurface earth formation traversed by a borehole. The method of the invention generally comprises generating one or more pairs of pressure waves using pairs of vibrating rods, where one element of a given pair vibrates in phase with one element of each of the other pairs (and out of phase with the other element of each of the other pairs), so that the pressure waves initially propagate within a sonde in substantially the same direction parallel to the longitudinal central axis thereof, and thence reflecting each wave radially outwards of the sonde and into the formation at approximately the same borehole elevation whereby a multipole shear wave is established in the formation.
The apparatus of the present invention generally comprises a sonde, adapted to be moved along the borehole, housing an acoustic wave generator means and an acoustic reflector means for respectively generating and reflecting radially outwards the aforesaid pressure waves.
In a preferred embodiment, four pressure waves are generated so at to propagate initially along four axes whose intersection with any plane perpendicular to the central axis of the sonde define the four corners of a quadrilateral and preferably a square. The hereinbefore noted subsequent reflection of any given one of these pressure waves into the formation is such that most of the energy in such reflected wave propagates wave is in a general direction normal to a plane defined by the two axes which in closest proximity to the axis of the given pressure wave. Moreover, the given pressure wave will be out of phase with the pressure waves initially propagating along such two nearest axes.
In such preferred embodiment, the acoustic wave generator means includes four cylindrical rods aligned coaxially along the four axes whereby the rod centers lie on a circle perpendicular to the central axis and are circumferentially equally spaced about the circle, thereby defining first and second pairs of such rods, each pair comprised of two diametrically opposed rods. The rods of the first pair are of an identical first magentostrictive material having a first strain constant and those of the second pair are, in like manner, of an identical magnetostrictive second material different from the first material and further having a second strain constant different from the first strain constant.
Coils around each rod, when electrically energized, induce a magnetic field in the rods parallel to their axes causing surface vibrations at the upper ends of the rods constituting a quadrupole motion, e.g., motion along the rod axes whereby motion of each rod of a given pair is in phase with one another but out of phase with those of the other pair, thereby generating the four pressure waves.
In an embodiment in which four pressure waves are generated by the acoustic wave generator means, the acoustic reflector means preferably comprises an acoustically reflective material defining an inverted, truncated, four-faced pyramid coaxially aligned with the central axs, whereby the upper end of each rod is disposed adjacent to and below a respective face and the axis of each rod intersects the respective face.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view, partly schematic, depicting an acoustic logging system of the present invention.
FIG. 2 is a pictorial view, partly in section, depicting a preferred embodiment of a quadrupole shear wave logging source illustrated in FIG. 1.
FIG. 3 is an elevational view, in cross-section, of the logging source of FIG. 2 taken on a plane which includes the longitudinal central axis common to the logging sonde depicted in FIG. 1 and the logging source of FIG. 2 contained therein.
FIG. 4 is a plan view in cross-section of the logging source of FIG. 3 taken along line 4--4.
FIG. 5 is a pictorial view of the rod elements and associated coils of the logging source of FIG. 2 illustrating schematically the electrical wiring thereof.
FIG. 6A is a pictorial view of the acoustic reflector of the logging source depicted in FIG. 2.
FIG. 6B is a plan (bottom) view of the acoustic reflector depicted in FIG. 6A.
FIG. 7 is a plan view in cross-section of a 16-pole shear wave logging source illustrating an alternate embodiment of the logging source of FIG. 3.
FIG. 8A is a pictorial view of the acoustic reflector of the alternate embodiment of the logging source depicted in FIG. 7.
FIG. 8B is a plan (bottom) view of the acoustic reflector depicted in FIG. 8A.
FIG. 9 is a pictorial view of an alternate embodiment of the rod elements and associated coils of the logging source of FIG. 2 illustrating schematically the electrical wiring thereof.
FIG. 10 is a cross-sectional view of a dipole acoustic shear wave source, taken in a plane perpendicular to the longitudinal central axis of the source, illustrating another embodiment of the invention.
FIG. 11 is a pictorial view of the acoustic reflector of the logging source depicted in FIG. 10.
FIG. 12 is a plan (bottom) view of the acoustic reflector depicted in FIG. 11.
FIG. 13 is a cross-sectional view of an octopole acoustic shear wave source, taken in a plane perpendicular to the longitudinal central axis of the source, illustrating another embodiment of the invention.
FIG. 14 is a pictorial view of the acoustic reflector of the logging source depicted in FIG. 13.
FIG. 15 is a plan (bottom) view of the acoustic reflector depicted in FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The multipole nomenclature is based on consecutive powers of two, that is, 2 n , n being an integer and n=1, 2, 3, and so on indefinitely. Thus, the multipoles include dipole (n=1), the quadrupole (n=2) and the octopole(n=3). The nomenclature for higher order multipoles is based upon 2 n with n=4, 5, 6, and so on indefinitely. The multipoles do not include the monopole (n=0).
FIG. 1 is a pictorial view of an acoustic logging system of the present invention adapted particularly for use in the logging of acoustic shear waves in a subsurface earth formation traversed by a borehole. A subsurface formation 10 to be investigated is traversed by a well borehole 12 typically containing a fluid 14. A logging sonde 16 is provided which is adapted to be moved vertically along the borehole 12 to the desired borehole elevation at which the formation is to be investigated.
The sonde 16 is conventionally of a sectional configuration, and may include an acoustic wave generating source section 18, and one or more acoustic wave detector sections such as sections 20, 22, and 24. Each detector section is provided with a corresponding detector, which detectors shall be collectively referred to as detector array 25. Detector sections 20, 22, and 24 contain, respectively, detectors D 1 , D 2 , and D n of detector array 25. Other detector sections containing other detectors of detector array 25 are not shown or are only partly shown in FIG. 1.
Similarly, source section 18 will house acoustic source 26 of the present invention. It will be noted that the detector sections 20, 22, and 24 will typically be physically isolated from the source section 18 by a spacer section 29 in a manner well known in the art, and that sections 18-24 will further be coaxially aligned about a longitudinal central axis 28 to form the cylindrical sonde 16. When the sonde 16 is disposed within borehole 12, central axis 28 will be seen to also preferably approximate the axis of borehole 12.
A closer inspection of FIG. 1 reveals that sections 18, 20, 22, and 24 are each provided with a respective set of acoustic windows 27, 36, 38 and 40. Although each of sets 27, 36, 38, and 40 is shown in FIG. 1 to include four windows, each set may include more than or less than four windows. In operation, source 26 will generate four acoustic wave pulses (only one of which is depicted as pressure wave 30) in a manner to be hereinafter described in greater detail. Each wave pulse will propagate away from source 26 at a θ angle 34 relative to the plane which includes line 32 and is normal to central axis 28. A portion of the acoustic energy in each wave pulse (including wave 30) will traverse borehole fluid 14, enter the formation 10, and travel longitudinally downward whereupon it will re-enter fluid 14, and be detected by the detectors of detector array 25 in a manner later described in more detail.
A firing and recording control unit 44 is used to control the energization of source 26 at appropriate desired times, functionally depicted by the presence of switch 42. Acoustic wave forms generated by detectors D 1 , D 2 and D n of detector array 25 in response to acoustic energy impinging thereupon from formation 10 will be delivered on respective signal lines 46, 48 and 50 (and other signal lines, not shown, corresponding to other detectors of detector array 25) to uphole circuitry 52, 54, 56, and 58 for processing, recording, display, and the like as desired.
More particularly, and as functionally depicted by switch 52, each signal on lines 46-50 will be filtered by an appropriate band pass filter 54, amplified by amplifier 56, and then delivered to a time interval unit 58, all in a manner and for purposes well known in the art. Travel times of the acoustic energy from source 16 through formation 10 to a given detector of detector array 25 may then be determined from which velocity of acoustic waves in the formation 10 may be derived.
FIG. 2 is a pictorial view, depicting a preferred embodiment of a quadrupole acoustic wave logging source 26 of the present invention illustrated in FIG. 1 and contained in section 18. The source 26 comprises a hollow cylindrical housing 60 through which passes a lower support mandrel 62. Mandrel 62 supports a disc-shaped base 64 which carries four cylindrical rods 66, 68, 70 and 72. A middle support mandrel 74 interconnects base 64 to an acoustic energy reflector 76, which, in turn, is interconnected to an upper support mandrel 78.
In the upper portion of housing 60 are windows 27 previously mentioned (only two of which are shown for clarity). Each window is an aperture, extending across which is a thin membrane such as rubber sheeting or the like which is substantially acoustically transparent, whereby acoustic pulses generated internally of the housing 60 may be transmitted through the membrane to the surrounding formation 10. The membrane will of course be sealingly engaged to the wall of housing 60, so as to prevent seepage of borehole fluid 14 into the interstices of housing 60, by any convenient means such as metal clips.
The lower base 64 will have provided on the outer cylindrical surface thereof a lower O-ring retainer groove 83 carrying an O-ring 84 which provides sealing engagement between base 64 and the internal surface of housing 60. Also, first, second, third, and fourth helical coils 86, 88, 90, and 92 will be seen disposed about respective rods 66, 68, 70, and 72, such coils being comprised of insulated coil electrical wire.
First and second apertures 94 and 96 extend transversely to middle mandrel 74 for receiving end leads of respective coils 86 and 88, routing these leads to an appropriate source of electrical power to be hereinafter described. Additional apertures (not shown) in mandrel 74 may be provided if necessary for routing ends leads of coils 90 and 92 in like manner.
Acoustic reflector 76 will, similarly to base 64, include an upper O-ring retainer groove 116 which carries an upper O-ring 118 for sealing engagement between the outer cylindrical periphery of reflector 76 and the inner surface of housing 60. In this manner, it will be understood that an inner volume 124 (shown in FIG. 3) will thus be provided which is sealed off from the outside of housing 60 and from areas above and below reflector 76 and base 64, respectively. Volume 124 will preferably be filled with a fluid such as oil or the like for acoustical impedance matching with fluid 14.
Referring now to FIGS. 3 and 4 in greater detail, it will be recalled that these FIGURES are, respectively, elevational and plan views of the acoustic source 26 of FIG. 2 showing additional detail thereof. First, it will be noted that internally and longitudinally of middle mandrel 74, reflector 76 and upper mandrel 78 along central axis 28 respective coaxially aligned passages 98, 100, and 102 are disposed.
Passage 98 communicates with apertures 94 and 96, thereby providing means for routing end leads of coils 86-92 through apertures 94 and 96 and through passages 98-102 to an appropriate source of electrical energy.
Still referring to FIGS. 3 and 4, threaded recesses 104 and 106 are provided in base 64, and threaded recesses 108 and 110 in reflector 76 for threadably receiving matingly threaded end portions of lower, middle and upper mandrels 62, 74, and 78, respectively. Similarly threaded recesses such as 112 and 114 in base 64 provide convenient means for mounting the four rods 66-72 to base 64.
Two permanent magnets 120 and 122 are shown disposed within and carried by reflector 76, each mounted coaxially with and above a respective one of rods 66 and 70, for purposes to be described later in more detail with respect to an alternate embodiment. It will be understood, however, that in the preferred embodiment of FIG. 3 the magnets will be omitted.
In FIG. 4, an X and Y axis, 126 and 128, respectively, have been illustrated perpendicular to each other and intersecting central axis 28 for facilitating the detailed described which follows. For like purpose, a circle 130 has been indicated therein lying in the plane defined by axis 126 and 128 and passing through the longitudinal axes or centers of rods 66-72.
FIG. 5 is a pictorial view of the rods 66-72 and corresponding coils 86-92 of the logging source 26 of FIG. 2, intended to depict functionally the electrical connection thereof and their configuration in more detail. In the preferred embodiment of the present invention, rods 66-72 are each constructed of a ferromagnetic material exhibiting the property known as the magnetostrictive phenomenon whereby when a magnetic field is applied to the material in the direction of its longitudinal axis, corresponding changes in length of the material in the direction of its longitudinal axis are produced.
The magnitude of the change and whether the material expands or contracts upon magnetization is a function of the particular material. Thus, various materials exhibit differing material strain constants (changes in length per unit length due to magnetostriction), some of which may be positive or negative (indicating the material lengthens or shortens with magnetization, respectively). Moreover, such constants may be either large or small (indicating larger or small percentage changes in length for a given magnetic field strength, respectively). Applying the foregoing to the embodiment of FIG. 5, it will be understood that the magnetostrictive phenomenon just described may be utilized to .[.constuct.]. .Iadd.construct .Iaddend.a magnetostrictive vibrator capable of generating an acoustic pressure wave. More particularly, in the embodiment of FIG. 5, rods 66 and 70 will desirably be constructed of a ferromagnetic material known as 2V Permendur having a positive strain constant, whereas rods 68 and 72 may be made of a ferromagnetic material such as nickel having a negative strain constraint with an absolute value less than that of 2V Permendur.
From the foregoing, it will be noted that upon application of a magnetic field to rods 66 and 70 by closing switch 42, and thereby energizing corresponding coils 86 and 90 from electrical energy source 132, the upper circular surfaces of the rods 66 and 70 (which lie in a plane parallel to that defined by axes 126 and 128) will move upwards as the rods 66 and 70 lengthen in the direction of central axis 28. (It will be recalled that the lower ends of rods 66-72 are mounted on base 64 and constrained from longitudinal movement.)
Upon opening the switch 42 and thereby de-energizing coils 86 and 90, rods 66 and 70 will return to their normal length. Accordingly, by varying the strength of the applied magnetic field, as, for example, by rapid opening and closure of switch 42, upper surfaces of rods 66 and 70 will oscillate in phase at the same frequency thereby creating two acoustic waves traveling vertically upwards toward reflector 76 along the axes of rods 66 and 70 and in the direction of central axis 28.
In like manner, because rods 68 and 72 have a strain constant of opposite sign to that of rods 66 and 70, upon simultaneous energization of their corresponding coils 88 and 92 with those of rods 66 and 70, upper circular surfaces of rods 68 and 72 will be made to oscillate in the direction of central axis 28 in phase with each other at the same frequency but 180° out of phase with those of rods 66 and 70. This will create two additional acoustic waves also traveling vertically upwards toward reflector 76 as previously described and out of phase therewith.
Due to the absolute value of the strain constants for 2 V Permendur being larger than that of nickel, for a given magnetic field strength, the amplitude of vibration of rods 66 and 70 would be larger than that of rods 68 and 72. Accordingly, in the embodiment of FIG. 5 just described, the number of turns of coils 86 and 90 may be made less than those of coils 88 and 92 in order to produce vibrations of approximately equal amplitude, which is desirable in order for source 26 to transmit quadrupole acoustic waves into formation 10.
In several embodiments disclosed herein, some of the rods used in constructing a source according to the present invention will have a first strain constant and some will have a second strain constant whose absolute value differs from that of the first strain constant. For example, the absolute value of the strain constant of nickel is about half of that of 2 V Permendur. In these embodiments, the effective strain constants of the rod materials used may be matched by wrapping the rods having larger absolute strain constant with an electrically conducting metal element (which may be a wire) so that the metal element is wrapped between each such rod and the corresponding surrounding energizing coil which produces the magnetic field at the rod. This wrap will partially shield the rod from the magnetic field, thus reducing the effective strain constant of the wrapped rod. For example, in a source having some nickel and some 2 V Permendur rods, a thin aluminum wire wrap around each 2 V Permendur rod will achieve the desired effect of matching the strain constants of the rods.
In FIGS. 6A and 6B there are illustrated a pictorial and plan view, respectively, of the acoustic reflector 76 within the logging sonde 26 of FIG. 2. In particular, the reflector 76 will be seen to define an inverted pyramid truncated by the surface adjacent recess 108. More particularly, the pyramid thus defined will further be seen to have four reflecting faces 134, 136, 138, and 140.
From the orientation of faces 134-140 relative to axes 126 and 128 and the coaxial alignment of reflector 76 along central axis 28, it will be understood that each rod 66-72 is disposed adjacent to and below a corresponding respective one of the faces 134-140, with the longitudinal axis of each rod intersecting its respective face.
The purpose of such alignment may be seen from the arrow 135 which represents an acoustic wave generated from one of the rods 66-72 as just described traveling longitudinally upwards in the direction of central axis 28 and along the axis of the particular rod toward reflector 76. Upon striking reflector 76, the wave will be reflected as wave 30 at a θ angle 34 relative the plane which includes to horizontal reference line 32 and is normal to central axis 28.
In this manner, by appropriately shaping faces 134-140, vertically traveling acoustic pressure waves generated by each rod 66-72 will be reflected in a direction generally normal to central axis 28 so that the main lobes of the acoustic wave energy reflected from reflector 76 will travel out of source section 18 (through set of windows 27), and into the formation 10 substantially in the four directions indicated by axes 126 and 128.
The reflector 76 is preferably constructed of an efficient acoustic reflector material such as aluminum or steel to maximize transfer of energy from the reflector to the formation. It has also been found desirable that the reflective wave lobes be reflected not at an angle exactly normal to central axis 28 but rather at an offset, desirably in the range of about 20° to about 45° with respect to a plane normal to central axis 28, in order to enhance conversion (in a manner described in the following two paragraphs) of the compressional wave thereby created in borehole fluid 14 to the desired quadrupole shear waves in formation 10. This may, of course, be accomplished by adjusting the angle of incline of faces 134-140 relative to central axis 28, adjusting the orientation of axes of rods 66-72 relative to faces 134-140, or both.
It should be recognized that at the interface between borehole fluid 14 and formation 10, not only will a portion of the compressional wave energy propagating in borehole fluid 14 away from source 26 be converted to acoustic shear wave energy which will also propagate in formation 10, but another portion of such compressional wave energy in fluid 14 will be converted to acoustic compressional wave energy which will propagate in formation 10. The shear waves induced in formation 10 will interfere to produce a quadrupole shear wave in formation 10. Similarly the compressional waves induced in formation 10 will interfere to produce a quadrupole compressional wave in formation 10. The ratio of quadrupole shear wave energy to quadrupole compressional wave energy produced by source 26 in formation 10 will depend on the aforementioned angle at which the pressure waves in fluid 14 are incident at the interface between fluid 14 and formation 10 and will also depend on the source frequency.
For direct acoustic shear wave logging, it is desirable to enhance generation of shear waves in formation 10 relative to generation of compressional waves therein. This may be accomplished in the manner described in the paragraph immediately preceding the above paragraph. In contrast, for efficient acoustic compressional wave logging it may be desirable to enhance generation of compressional waves in formation 10 relative to generation of shear waves therein.
Source 26, operated in the same mode described herein with reference to quadrupole shear wave logging, may be used for performing quadrupole acoustic compressional wave logging. The quadrupole compressional wave arrival at the detectors will occur prior to the quadrupole shear wave arrival at the detectors, so that the concurrent generation of quadrupole shear waves in formation 10 (with the quadrupole compressional waves of interest in quadrupole compressional wave logging) will not hinder compressional wave logging operations. To efficiently perform quadrupole acoustic compressional wave logging using source 26, it is desirable that the angle of incline of faces 134-140 relative to central axis 28 and the orientation of the axes of rods 66-72 relative to faces 134-140 be adjusted so that the reflective wave lobes propagate in a direction normal to central axis 28, so that generation of compressional waves in formation 10 is enhanced relative to generation of shear waves therein.
It will be apparent to those ordinarily skilled in the art that the dipole, octopole, and other embodiments of the acoustic source of the present invention described below are similarly suitable for either multipole acoustic shear wave logging or for multipole acoustic compressional wave logging.
It has also been noted that it is desirable that the upward traveling acoustic waves from each upper rod 66-72 surface originate from points as radially inward toward central axis 28 as practicable. This is in order to approximate as closely as possible four closely spaced monopole sources which are required for a quadrupole source and may be effected by decreasing the diameter of circle 130 about which the rods 66-72 are evenly spaced.
ALTERNATE EMBODIMENTS
FIGS. 7, 8A, and 8B correspond to FIGS. 4, 6A, and 6B, respectively, in that they depict similar views of an alternate embodiment of the present invention. Specifically, whereas the preceding description of the present invention has been limited to a quadrupole wave generator or source, the invention is not intended to be so limited and fully contemplates other embodiments.
Thus, in accordance with the references cited herein, for some applications a dipole acoustic wave source, as illustrated in FIGS. 10, 11, and 12, or a source of higher order than the quadrupole source, such as the octopole acoustic wave source illustrated in FIGS. 13, 14, and 15, or the 16-pole acoustic wave source illustrated in FIGS. 7, 8A, and 8B may be desired.
The number of rods in the embodiments of the dipole, the octopole, and the 16-pole .[.souce.]. .Iadd.source .Iaddend.to be described below does not match the nomenclature of the dipole, octopole, and 16-pole sources. Thus, a dipole (n=1) source comprises two times one or two rods. A quadrupole (n=2) source comprises two times two or four rods. An octopole (n=3), a 16-pole (n=4) and a 32-pole (n=5) source comprises six, eight, and ten rods respectively. Therefore, in general a 2 n -pole source will comprise 2n rods, n being an integer where n=1, 2, 3, and so on indefinitely.
In general, for a 2 n -pole source of the present invention, 2n rods (where n=1, 2, 3, and so on indefinitely) are disposed substantially evenly about the central axis of a logging sonde. Preferably, the rods are disposed substantially evenly about the central axis. Adjacent rods, with respect to angular position about the central axis, produce pressure waves which are substantially 180° out of phase with respect to each other and which initially propagate toward the reflector and are thereafter reflected generally radially outward from the central axis.
Accordingly, referring now to FIG. 7 in comparison to FIG. 4, it may be appreciated that instead of only four rods 66-72, eight rods 158, 160, 162, 164, 166, 168, 170, and 172 are provided (with corresponding coils which are not shown) as well as eight corresponding windows 142, 144, 146, 148, 150, 152, 154, and 156 radially outwards from the rods.
In similar manner to the embodiment of FIGS. 1-6B, the eight rods 158-172 and corresponding coils will be oriented so that their centers are evenly spaced about the circumference of circle 130 and their axes are parallel to central axis 28. Similarly, the rods will alternate between a first and second ferromagnetic material as circle 130 is circumferentially traversed. Finally, the rods may be energized in a manner similar to that functionally depicted in FIG. 5.
It will thus be understood that in the embodiment of FIGS. 7, 8A, and 8B, instead of four pressure waves being produced which travel upwards within the sonde 16 toward reflector 76, eight such waves will be produced. Accordingly, it is necessary to modify reflector 76 as depicted in FIGS. 8A and 8B so as to provide corresponding reflecting surfaces 174, 176, 178, 180, 182, 184, 186, and 188, which will cause each such wave to be reflected out its respective window 142, 146, 148, 150, 152, 154, and 156, into formation 10 in eight separate and distinct radially outward directions from central axis 28.
FIG. 10 is a cross-sectional view of a dipole acoustic shear wave source illustrating another embodiment of acoustic source 26 of the invention. Instead of four rods, only two rods 258 and 260 are provided (with corresponding helical coils which are not shown) as well as two corresponding windows 254 and 256 radially outwards from rods 258 and 260 respectively.
In a similar manner to the embodiment of FIGS. 1 through 6B, rods 258 and 260 and corresponding coils are oriented substantially 180° away from each other on the circumference of circle 230 and their axes are parallel to central axis 28. Similarly, one of rods 258 and 260 is made of a first magnetostrictive material having a positive strain constant (such as a 2 V Permendur) and the other is made of a second magnetostrictive material having a negative strain constant (such as nickel). Rods 258 and 260 are energized in a manner similar to that functionally depicted in FIG. 5.
It will thus be understood that in the embodiment of FIG. 10, two pressure waves (one 180° out of phase with respect to the other) will be produced as to propagate initially within sonde 16 toward reflector 278. Reflector 278 is positioned above the upper ends of rods 258 and 260 by threading threaded recess 208 onto matingly threaded upper end portion of mandrel 74.
Reflector 278, depicted in FIGS. 11 and 12 is provided with reflecting surfaces 274 and 276, for respectively reflecting the pressure waves from rods 258 and 260 out windows 254 and 256, so as to propagate substantially radially outward from central axis 28. Reflector 278 is generally shaped as an inverted solid cone, truncated by the surface adjacent recess 208, and having reflecting surfaces 274 and 276 formed on oppositely facing regions of its generally conical outer surface. The axes of rods 258 and 260 intersect faces surfaces 274 and 276, respectively, when reflector 278 is properly positioned relative to the rods.
FIG. 13 is a cross-sectional view of an octopole acoustic shear wave source illustrating yet another embodiment of acoustic source 26 of the invention. Referring to FIG. 13 in comparison with FIG. 4, it may be appreciated that instead of only four rods 66-72, six rods 358, 360, 362, 364, 366, and 368 are provided (with corresponding coils which are not shown) as well as six corresponding windows 344, 346, 348, 350, 352, and 354 radially outwards from the rods.
In similar manner to the embodiment of FIGS. 1-6B, the six rods 358-368 and corresponding coils will be oriented so that their centers are evenly spaced about the circumference of circle 370 and their axes are parallel to central axis 28. Similarly, the rods will alternate between a first and second ferromagnetic material as circle 370 is circumferentially traversed. Finally, the rods may be energized in a manner similar to that functionally depicted in FIG. 5.
It will thus be understood that in the embodiment of FIGS. 13, 14, and 15, instead of four pressure waves being produced which travel upwards within the sonde 16 toward reflector 76, six such waves will be produced. Accordingly, it is necessary to employ a modified reflector 376 as depicted in FIGS. 14 and 15 (rather than reflector 76 in the embodiment depicted in FIGS. 6A and 6B) so as to provide six corresponding reflecting surfaces 380, 382, 384, 386, 388, and 390, which will cause each such wave to be reflected out its respective window 344, 346, 348, 350, 352, and 354, into formation 10 in six separate and distinct radially outward directions from central axis 28.
It will be recalled from the foregoing that in the embodiment of FIG. 3 it was mentioned that in an alternate embodiment thereof it is desirable to provide two biasing magnets (such as those two depicted therein as 120, 122). This alternate embodiment will now be discussed in greater detail.
In the alternate embodiment presently being discussed, all the rods thereof such as rods 66-72 of FIG. 3 may be made of the same ferromagnetic material, a material chosen with a relatively high strain constant in order to produce relatively higher vibrational amplitudes of the rods and accordingly a stronger acoustic source.
One problem with using rods of the same material is in achieving the desired hereinbefore noted out-of-phase relationship between the generated acoustic waves (generated by each rod and achieved previously due to use of rods with two differing strain constants). By providing a biased magnetic field on two diametrically opposed rods such as 66 and 70 of the four depicted in FIG. 3, this out-of-phase operation may nevertheless still be achieved.
More particularly, rods 66 and 70 may, for example, be prestrained by corresponding permanent magnets 120 and 122 carried above them in reflector 76 (alternatively electromagnetic coils may be substituted for magnets 120 and 122 in some applications in which permanent magnets might be prohibitively bulky).
These rods 66 and 70 will either be strained further or relieved from prestrained conditions as a function of the direction of the magnetic field applied by corresponding coils 86 and 90 to rods 66 and 70. Whereas magnetostrictive material having a positive strain constant will elongate (and magnetostrictive material having a negative strain constant will contract) with magnetization independent of the sign (positive or negative) of the magnetic field applied, the amount of such movement is related to the absolute magnitude of the applied magnetic field.
Thus, by alternating the direction of the energizing current to coils 86 and 90, the magnitude of the net magnetic field exerted on rods 66 and 70 may be made to vary on either side of the pre-biased or prestrained value, thereby causing the rods 66 and 70 to move in either desired direction of central axis 28 from a prestrained position either to a less or greater strained position. This, in turn, permits creation of the desired out-of-phase motion between diametrically opposed rod pairs 66-70 and 68-72.
Referring now to FIG. 9, yet another embodiment of the present invention may be seen depicted therein. More particularly, FIG. 9 depicts an alternative method of constructing the vibrating rods utilized in the embodiments of the acoustic wave source illustrated in FIGS. 3, 7, or 10.
Each magnetostrictive rod with associated coil, such as rod 66 and coil 86 of FIG. 3, may have substituted therefor a piezoelectric rod such as the four shown in FIG. 9 in exploded view.
Each rod will be seen to be comprised of a plurality of polarized discs such as disc 198, 200, 204, and 206 of FIG. 9 fashioned from a suitable piezoelectric crystal material, such as that commercially supplied by the Vernitron Company of Bedford, Ohio. These discs will be stacked and coaxially aligned along respective axes 190, 192, 194, and 196. These axes will be seen to correspond to longitudinal axes of previously described rods 66-72 extending parallel to center axis 28.
Piezoelectric crystals have the property that they will either expand or contract in response to an applied electrical potential and whether the crystal expands or contracts is controllable by the direction of the applied potential and the direction of the crystal polarization.
Accordingly, with the crystal discs 198-206 polarized according to the arrows as shown, stacked, and wired, it will be understood that because wiring of stacks aligned along axis 190 and 194 is opposite to those aligned along axis 192 and 196, upon energization of all four stacks from energy source 132 by closing switch 42, two diametrically opposed stacks will expand longitudinally in the direction of central axis 28, whereas the remaining two will contract, thus achieving the desired generation of two sets of out-of-phase longitudinal acoustic waves previously described with respect to the embodiment of FIG. 2.
As previously noted, due to the longitudinal displacement mode of the rods of the present invention and further due to the relatively greater longitudinal dimensions of sonde 16 (as opposed to transverse dimensions) available for housing a vibrating member, it is possible to build acoustic sources in accordance with the teachings of the present invention which may generate extremely powerful out-of-phase acoustic pressure waves in the sonde 16 sufficient to easily establish strong dipole, quadrupole, or higher order shear waves in the formation of interest.
The desired frequency of the acoustic waves to be generated will govern the choice of the particular lengths of rods 66-72 in a manner well known in the art, inasmuch as the natural frequency of the rods, a function of their length, will be related to this desired frequency. However, for acoustic shear wave logging the typical desired frequency ranges of oscillation for rods 66-72 in the quadrupole embodiment shown in FIG. 2 will be in the range of just below 3 KHz to about 14 KHz or even higher, with frequencies about 3 KHz being often typical for direct shear wave logging relatively "soft" formations and about 6 KHz or higher for direct shear wave logging in "hard" formations.
Due to the strength of acoustic waves which may be generated with the sonde of the present invention, it has been found that the first harmonic of the nominal oscillating frequency of the rods (which first harmonic is also present in the oscillations) may be of sufficient magnitude such that the source 26 may be operated for both soft and hard formations at the same frequency.
Moreover, also due to the strength of the instant source, well-to-well logging may even be achieved wherein the formation may be acoustically excited at one borehole situs and the acoustic signature detected at an adjacent borehole situs.
Because oscillating magnetostrictive rods may be provided which are energized by magnetic fields, relatively small power supply requirements of low voltage are required to energize their respective coils. This is a distinct advantage over conventional piezoelectric vibrating elements which characteristically require higher voltage supplies with attendant noise problems and the like. However, when "stacked array" rods of a piezoelectric disc material are substituted for magnetostrictive rods, as in the case of the alternate embodiment of FIG. 9, these problems may be reduced by careful design.
It will be appreciated that the operating principles of the sonde 26 of the present invention disclosed herein may be adapted with relatively minor changes to construct acoustic wave detectors, and such detectors are accordingly specifically within the scope and spirit of the subject invention.
For example, with reference to FIG. 2, it is readily apparent that if the source depicted therein is used as a detector, acoustic waves from the formation to be detected will travel opposite to those generated when it is acting as a source. More particularly, acoustic waves will enter through windows 79, 81, etc., and be reflected downward by reflector 76 onto rods 66-72.
This energy impinging upon rods 66-72 will cause vibrations therein which may be used to induce measurable potential signal levels in coils 86-92 functionally related to the acoustic waves.
It is therefore apparent that the present invention is one well adapted to obtain all of the advantages and features hereinabove set forth, together with other advantages which will become obvious and apparent from a description of the apparatus itself. It will be understood that certain combinations and subcombinations are of utility and may be employed without reference to other features and subcombinations. Moreover, the foregoing disclosure and description of the invention is only illustrative and explanatory thereof, and the invention admits of various changes in the size, shape and material composition of its components, as well as in the details of the illustrated construction, without departing from the scope and spirit thereof.
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Method and apparatus for acoustic wave generation and transmission into a subsurface earth formation. A logging sonde adapted to be suspended in a borehole within the formation houses a generator means for simultaneously generating a plurality of acoustic waves traveling in the direction of and spaced substantially evenly about the .[.logitudinal.]. .Iadd.longitudinal .Iaddend.axis of the sonde. An acoustic energy reflector means within the housing reflects the waves radially outwards of the axis and into the formation at angles generally perpendicular to the axis. Detectors within the housing spaced longitudinally from the generator and reflector detect acoustic energy in the formation resulting from the reflected waves. In a preferred embodiment, the generator means comprises four cylindrical magnetostrictively energized elements disposed about the central axis of the sonde, each having an axis parallel to the central axis, so that the four axes of the elements, when viewed in the direction of the central axis, define four corners of a square. The elements are designed so that upon energization, a given element vibrates longitudinally out of phase relative to the two elements adjacent thereto, vibration of the four elements in concert generating two positive and two negative waves which, when reflected into the formation, interfere to produce a quadrupole shear wave.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a method for forming a die protecting layer, and more particularly to a method for forming a die protecting layer on one side of a wafer opposite to the other side having dies.
[0003] 2. Description of the Prior Art
[0004] For contemporary semiconductor field, the chip formed on the wafer has a minute and delicate structure, and usually is incorporated with other elements (such as capacitor or inductor) to form an integrated circuit. Hence, the chip usually is packaged after its formation and before its operation.
[0005] FIG. 1A shows a wafer 10 having a plurality of light emitting diode (LED) dies 11 to be packaged, wherein each LED die 11 has electrodes 16 . The wafer 10 must be scribed to separate every LED die 11 in order to package every LED die 11 . FIG. 1B and FIG. 1C show results of forming protecting layers on LED dies 11 respectively. The LED die 11 shown in FIG. 1B emits light from the backside and hence the protecting layer 12 is formed on the light emitting side. The protecting layer 12 comprises a transparent material and a fluorescence material. The LED die 11 shown in FIG. 1C emits light from the front side and the protecting layer 14 is formed on the electrodes 16 . The protecting layer 14 comprises a transparent material with fluorescence materials of various colors. Since the protecting layer must be applied to each LED die 11 one by one, applying the protecting layer to every LED die 11 would cost lots of production time and work force. Moreover, manually applying the protecting layer to each LED die 11 would cause variation of production standard and unstable quality thereby increase production cost and decrease the yield ratio.
[0006] Since the conventional technology still has above mentioned drawbacks. It is desired to further develop new technologies to overcome the drawbacks.
SUMMARY OF THE INVENTION
[0007] One main object of the invention is to provide a method for forming a die protecting layer to solve issues of production standard variation and unstable quality.
[0008] Another main object of the invention is to provide a method for forming a die protecting layer to decrease production cost and increase yield ratio.
[0009] Still a main object of the invention is to provide a method for forming a die protecting layer to increase convenience for the following package process.
[0010] The method of the invention comprises the following steps. First of all, a wafer having a plurality of dies, a first surface and an opposite second surface is provided, wherein the dies are on the first surface. Then a transparent polymer material and fluorescence materials are pre-mixed to form a transparent protecting material. Next the transparent protecting material is applied to and covers the first surface or the second surface. Finally, the transparent protecting material is cured by heating to form a transparent protecting layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the accompanying drawing forming a material part of this description, there is shown:
[0012] FIG. 1A shows a wafer having a plurality of light emitting diode (LED) dies to be packaged;
[0013] FIG. 1B and FIG. 1C show results of forming protecting layers on LED dies respectively;
[0014] FIG. 2A shows a wafer having a first surface and an opposite second surface as well as a plurality of light emitting diode (LED) dies to be packaged;
[0015] FIG. 2B shows a transparent protecting layer formed on the second surface and covers the second surface;
[0016] FIG. 2C shows the transparent protecting material formed on the first surface and covers the first surface; and
[0017] FIG. 3 shows the method for forming a die protecting layer of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings.
[0019] Furthermore, the key characters of the invention are related to the method of packing dies but are not related to the amendment(s) of dies' structures or dies' distribution. Therefore, to avoid the risk of confusing and to simply the drawings, all drawings only show the existence of dies and electrodes but never show the real shape of dies and electrodes.
[0020] Referring to FIG. 2A , a wafer 20 having a first surface and an opposite second surface is shown. Herein, numerous dies 22 are formed in/on the first surface and the wafer 20 comprises a transparent wafer or a translucent wafer. Herein, each die 22 has at least one electrode 23 .
[0021] Referring to FIG. 2B , a transparent protecting layer 24 is formed on the second surface and covers the second surface. The transparent protecting layer 24 comprises transparent polymer materials with fluorescence materials of various colors or combinations thereof. The transparent protecting layer 24 is formed by mixing the transparent polymer materials and the fluorescence materials firstly to form a transparent protecting material so that the die 22 can illuminate lights of various colors. Then the transparent protecting material is formed on the second surface by a spin-on process, a coating method, a squeeze method and a sol-gel process. The transparent polymer material comprises, but is not limited to, the following material or the any combinations of the following materials: spin-on glasses, epoxy, Acrylonitrile butadiene styrene copolymer resin, gum, epoxy, Polyimide, plexus, silicone, transparent material and translucent material, Polyetherimides, polyamide-Imide, Polyphenylene sulfide, and Polymethyl Methacrylate. Any materials having suitable viscosity, transparency, heat resistance and mechanical strength could be used.
[0022] The transparent polymer material of the transparent protecting material is then cured to form the transparent protecting layer 24 which covers the second surface. The transparent protecting material is heated to over a curing temperature to form the transparent protecting layer 24 . The curing temperature is adjusted to a level until the dies 22 of the wafer 20 would be harmed. For example, the curing temperatures of general package materials such as epoxy are in the range of about 150˜200° C., the curing temperatures of the transparent polymer materials are in the range of about 150˜300° C.
[0023] The transparent protecting layer 24 can also be formed on the first surface of the wafer 20 instead of the second surface according to various package specifications. As shown in FIG. 2C , the transparent protecting material is formed on the first surface and covers the first surface. The transparent polymer material of the transparent protecting material is then cured to form the transparent protecting layer 24 which covers the first surface. The transparent protecting material comprises transparent polymer materials with fluorescence materials of various colors such as red, yellow, green, blue, white or combinations thereof. The transparent protecting layer 24 is formed by mixing the transparent polymer materials and the fluorescence materials firstly to form a transparent protecting material so that the die 22 can illuminate lights of various colors. The transparent protecting material is formed on the first surface by a spin-on process, a coating method, a squeeze method and a sol-gel process. The transparent polymer material comprises, but is not limited to, the following material or the any combinations of the following materials: spin-on glasses, epoxy, Acrylonitrile butadiene styrene copolymer resin, gum, epoxy, Polyimide, plexus, silicone, transparent material and translucent material, Polyetherimides, polyamide-Imide, Polyphenylene sulfide, and Polymethyl Methacrylate. Any materials having suitable viscosity, 20 transparency, heat resistance and mechanical strength could be used.
[0024] Comparing to the conventional technologies, the invention forms the transparent protecting layer on either side of the wafer before the wafer is scribed while the conventional technologies scribe the wafer into dies and uses additional tools to mount the dies and apply the protecting layer thereon. Therefore, the invention can effectively simplify package process and decrease package cost. Moreover, all dies are separated after the protecting layer is formed.
[0025] Referring to FIG. 3 , the method for forming a die protecting layer comprises the following steps. First of all, a wafer having a plurality of dies, a first surface and an opposite second surface is provided, wherein the dies are on the first surface as shown in step 32 . Then as shown in step 34 , a transparent polymer material and fluorescence materials are pre-mixed to form a transparent protecting material. Next the transparent protecting material is applied to and covers the first surface or the second surface as shown in step 36 . Finally, the transparent protecting material is cured by heating to form a transparent protecting layer as shown in step 38 .
[0026] Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from what is intended to be limited solely by the appended claims.
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A method for forming a die protecting layer is disclosed. The method comprises the following steps: providing a wafer with numerous dies on a first surface and a second surface, forming a transparent protecting layer on the second surface of the wafer. Clearly, the transparent protecting layer is directly formed on the backside or the front side of the wafer.
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TECHNICAL FIELD
[0001] This invention relates to electronic devices that are operated in synchronism with a clock signal, and more particularly to a system and method for compensating for variations in the propagation delay of clock signals in comparison to the propagation delay of other signals.
BACKGROUND OF THE INVENTION
[0002] The operating speed of electronic devices, such as memory devices, can often be increased by synchronizing the operation of the device to a clock signal. By operating the device synchronously, the timing at which various function occur in the device can be precisely controlled thereby allowing the speed at which these functions are performed to be increased by simply increasing the frequency or speed of the clock signal. However, as the speeds of clock signals has continued to increase with advances in semiconductor fabrication techniques, the propagation delays of clock signals within integrated circuit devices have become a problem. More specifically, internal clock signals are often generated from an external clock signal applied to the integrated circuit device. These internal clock signals are coupled throughout the integrated circuit device to control the timing of a variety of circuits. The times required for the internal clock signals to propagate to these circuits is difficult to either control or predict. As clock speeds continue to increase, the unpredictable and/or uncontrolled variations in internal clock signal propagation times can cause internal clock signals to be applied to circuits either too early or too late to allow the circuits to properly perform their intended functions. This problem, known as “clock skew,” threatens to limit the speed at which integrated circuit devices can function.
[0003] Various solutions have been proposed to address this clock skew problems. Some of these solutions are described in Takanori Saeki et al., “A Direct-Skew-Detect Synchronous Mirror Delay for Application-Specific Integrated Circuits,” IEEE Journal of Solid - State Circuits , Vol. 34, No. 3, March 1999. The article by Takanori Saeki et al. describes both open-loop and closed-loop clock skew compensation approaches. Closed-loop approaches include the use of phase-locked loops (“PLL”) and delay-locked loops (“DLL”) to synchronize the phase or timing of an internal clock signal to the phase or timing of an external clock signal used to generate the internal clock signal. These closed-loop approaches use a feedback signal to indicate the timing variations within the device. A phase comparator, such as a phase detector, is required to compare the phase or timing of the feedback signal to the phase or timing of a reference signal. Unfortunately, a significant amount of time may be required to achieve lock of the PLL or DLL.
[0004] Open-loop designs described in the Takanori Saeki et al. article include synchronized mirror delay (“SMD”) circuits and clock synchronized delay (“CSD”) circuits. CSD circuits generally include a variable delay line, usually a series of inverters, and latch circuits for selecting the output of one of these inverters as the delay line output. An internal clock signal is applied to the CSD circuit, and the magnitude of the delay provided by the CSD circuit is controlled in an attempt to set the phase or timing at which the internal clock signal is applied to an internal circuit. SMD circuits are basically the same as CSD circuits except that CSD circuits require the use of latches to store information. On the other hand, SMD circuits require specially shaped input clock signals. In order to generate internal clock signals on both the rising and falling edges of a clock signal (i.e., double data rate operation), SMD circuits, but not CSD circuits, require two variable delay lines, one for the clock signal and one for its compliment. In view of the similarity of CSD circuits and SMD circuits, they will be generically referred to herein as CSD/SMD circuits.
[0005] A conventional CSD/SMD circuit 10 described in the Takanori Saeki et al. article is shown in FIG. 1. An external clock signal XCLK is applied to an input buffer 12 , and the output of the buffer 12 is applied to a delay model circuit 14 . The output of the delay model circuit 14 is coupled through a measurement delay line to set a delay of a variable delay line 20 . The delay of both the measurement delay line 16 and the variable delay line 20 is set to integer multiples of a clock period of the external clock signal less the delay of the delay model circuit 14 , i.e., n*tCLK−d mdl , where n is an integer, tCLK is the period of the XCLK signal, and d mdl is the delay of the delay model circuit 14 . The variable delay line 20 outputs a clock signal to a clock driver 24 . The clock driver 24 then outputs an internal clock signal ICLK to an internal clock line 28 . The internal clock line 28 is coupled to a number of internal circuits 32 through respective circuit paths, which are collectively known as a “clock tree” 36 .
[0006] The external clock signal XCLK is coupled through the input buffer 12 with a delay of d 1 , through the measurement delay line 16 with a delay of d 2 , through the variable delay line 20 with a delay of d 3 , and through the clock driver 24 with a delay of d 4 . For the phase of the internal clock signal ICLK to be synchronized to the phase of the external clock signal XCLK before the CSD/SMD circuit 10 has been locked, the sum of these delays, i.e., d 1 +d mdl +d 2 +d 3 +d 4 , should be equal to integer multiples of one period tCLK of the external clock signal XCLK.
[0007] In operation, the delay d 3 of the variable delay line 20 is set in a conventional manner so that it is equal to the delay of the measurement delay line 16 . The delay d 2 of the measurement delay line 16 is set by conventional means to the difference between integer multiples of the period tCLK of the external clock signal XCLK and the delay d mdl of the delay model circuit 14 , i.e., d 2 =n*tCLK−d mdl . Thus, after one clock period tCLK, the delay d 3 of the variable delay line 20 has been determined. The total delay from the input of the input buffer 12 to the internal clock line 28 is given by the equation: d 1 +d 3 +d 4 . The delay d mdl of the delay model circuit 14 is set to the sum of the delay d 1 of the input buffer 14 and the delay d 4 of the clock driver 24 . This can be accomplished by implementing the delay model circuit 14 with a “dummy” input buffer 42 and a “dummy” clock driver 44 . The dummy input buffer 42 is preferably identical to the input buffer 12 and thus also provides a delay of d 1 . Similarly, the dummy clock driver 44 is preferably identical to the clock driver 24 and thus also produces a delay of d 4 . Using the equation d 3 =d 2 =n*tCLK−d mdl , the above equation d 1 +d 3 +d 4 for the total delay can be rewritten as: d 1 +n*tCLK−d mdl +d 4 . Combining this last equation and the equation d mdl =d 1 +d 4 allows the equation for the total delay from the input of the input buffer 12 to the ICKL line 28 to be rewritten as: d 1 +n*tCLK−d 1 −d 4 +d 4 . This last equation can be reduced to simply n*tCLK, or 1 clock period of the external clock signal XCLK, assuming the delay of the delay model circuit 14 is less than a period of the external clock signal, i.e., d mdl <tCLK. Thus, by using the delay model circuit 14 to model the delay d 1 of the input buffer 12 and the delay d 4 of the clock driver 24 , the phase of the internal clock signal ICLK can be synchronized to the phase of the external clock signal XCLK. Moreover, the total lock time, including the delay through the delay model circuit 14 and the measurement delay line 16 , is equal to d 1 +d mdl +d 2 +d 3 +d 4 , which can be reduced to 2n*tCLK. Therefore, this phase matching of the ICLK signal can be accomplished after only two periods of the external clock XCLK signal so that the integer “n” may be set equal to one.
[0008] Although the SMD/CSD circuit 10 shown in FIG. 1 can properly synchronize the phase of the internal clock signal ICLK to the phase of the external clock signal XCLK, it does so only at the internal clock line 28 . The SMD/CSD circuit 10 does not compensate for propagation delays in the clock tree 36 used to couple the internal clock signal ICLK from the internal clock line 28 to the internal circuits 32 .
[0009] An SMD/CSD circuit 48 somewhat similar to the SMD/CSD circuit 10 can be used in a clock skew compensation circuit 50 as shown in FIG. 2 to compensate for propagation delays in a clock tree. The SMD/CSD circuit 48 is shown as being used to generate an internal clock signal from an external clock signal XCLK that is used to latch an external data signal DATA in a latch 52 . The external data signal is coupled to the latch through a data input buffer 56 having a delay of d 1 . The external clock signal XCLK is applied to an input buffer 60 having a delay of d 2 , and the output of the input buffer 60 is applied through a delay model circuit 62 to a measurement delay line 64 . The delay model circuit 62 has a delay of d mdl , and the measurement delay line 64 has a delay of d 3 . The output of the input buffer 60 is also applied to a variable delay line 70 that is controlled so that it has the same delay d 3 as the measurement delay line 64 , as previously explained. The output of the variable delay line 70 is applied to a clock driver 74 having a delay of d 4 . Finally, the internal clock signal has a propagation delay of d 5 as it is coupled through a clock tree 78 from the clock driver 74 to the clock input of the latch 52 .
[0010] The total delay from the input of the input buffer 60 to the clock input of the latch 52 is thus given by the equation: d 2 +d 3 +d 4 +d 5 after the delay of the variable variable delay line 70 is determined. For the internal clock signal to enable the latch 52 to capture the data signal, the total delay should be reduced by the delay d 1 of the DATA signal propagating through the data input buffer 56 . The timing relationship between the XCLK signal and the DATA signal as they are applied to the latch 52 will then be the same as the timing relationship between the XCLK signal and the DATA signal as they are externally received. The XCLK signal is coupled to the latch with a total delay of: d 2 +d 3 +d 4 +d 5 . Substituting d 3 =[n*tCLK−d mdl ] in the above equation yields for the total delay: d 2 +[n*tCLK−d mdl ]+d 4 +d 5 . If the delay model circuit 62 models not only the delays of the input buffers 56 , 60 and the clock driver 74 , but also the delay d 5 of the clock tree 78 , the delay of the delay model circuit 62 is given by the formula: d mdl =d 2 −d 1 +d 4 +d 5 . The above equation for the total delay can then be expressed as: d 2 +[n*tCLK−d 2 +d 1 −d 4 −d 5 ]+d 4 +d 5 . This equation can be reduced to simply n*tCLK+d 1 , or n periods of the XCLK signal plus the delay of the DATA signal through the input buffer 56 . Letting n-i, the XCLK signal will thus be applied to the latch 52 one clock periods after the DATA signal is applied to the latch 52 so that the XCLK and DATA signals will have the same timing relationship at the latch 52 as the XCLK and DATA signals have at the external input terminals. To calculate the time for the SMD/CSD circuit 48 to achieve lock, the total delay time should be increased by the delay d mdl of the delay model circuit 62 and the delay d 3 of the measurement delay line 64 . Thus, the total time to achieve lock is d 2 +d mdl +(n*tCLK−d mdl )+(n*tCLK−d mdl )+d 4 +d 5 , which, for n=1 and d mdl <tCLK, can be reduced using the formula d mdl =d 2 −d 1 +d 4 +d 5 to 2*tCLK+d 1 .
[0011] The clock skew compensation circuits 50 improves the operation of synchronous digital circuits by attempting to compensate for propagation delays in a clock tree 78 coupled to a latch 52 . As explained above, the circuit 50 attempts to compensate for clock tree propagation delays by attempting to model the propagation delay of the clock tree 78 . However, it is significantly more difficult to model the propagation delay of the clock tree 78 compared to modeling the propagation delay of other circuits, such as the input buffers 56 , 60 and the clock driver 74 . The input buffers 56 , 60 and clock driver 74 , for example, can be modeled by simply including “dummy” buffers and drivers in the delay model circuit 62 . But it is generally not practical to include an entire clock tree in the delay model circuit 62 . Moreover, propagation delays can be different in different branches of the clock tree 78 , and the propagation delay in even a single branch of the clock tree 78 can vary as a function of time and temperature, for example. With the continued increases in clock speed needed to increase the operating speed of integrated circuit devices, these variations in the propagation delays in the clock tree 78 can prevent the proper operation of integrated circuit devices.
[0012] There is therefore a need for a suitable system and method for compensating for clock signal skew as internal clock signals are coupled to various circuits through a clock tree.
SUMMARY OF THE INVENTION
[0013] A clock skew compensation circuit according to the present invention includes a synchronized mirror delay or clock synchronized delay having a measurement delay line and a variable delay line. A clock signal is coupled to the variable delay line of the synchronized mirror delay, optionally through a buffer that may delay the clock signal by a first delay value. A clock tree is coupled to an output terminal of the synchronized mirror delay. The clock tree generates a feedback signal that is coupled to an input terminal of the measurement delay line input terminal. The feedback signal corresponds to the propagation delay of the clock signal being coupled through the clock tree. The clock signal coupled through the clock tree may be used to capture a digital signal in a suitable circuit, such as a latch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a block diagram of a conventional synchronized mirror delay circuit that can be used to compensation for some clock signal skew in integrated circuit devices.
[0015] [0015]FIG. 2 is a block diagram of a conventional clock skew compensation circuit using a synchronized mirror delay circuit.
[0016] [0016]FIG. 3 is a block diagram of a clock skew compensation circuit according to one embodiment of the invention.
[0017] [0017]FIG. 4 is a block diagram of a clock skew compensation circuit according to another embodiment of the invention.
[0018] [0018]FIG. 5 is a block diagram of a memory device using a clock skew compensation circuit in accordance with an embodiment of the invention.
[0019] [0019]FIG. 6 is a block diagram of a computer system using the memory device of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0020] A clock skew compensation circuit 110 according to one embodiment of the invention is shown in FIG. 3. The compensation circuit 110 includes an SMD/CSD circuit 114 having a measurement delay line 116 and a variable delay line 118 that operate in the same manner as the SMD/CSD circuits described with reference to FIGS. 1 and 2. An external clock signal XCLK is applied to the SMD/CSD circuit 114 through an input buffer 120 that introduces a delay of d 1 . Each of the delay lines 116 , 118 in the SMD/CSD circuit 114 introduces a delay of d 2 . The output of the SMD/CSD circuit 114 is applied to one input of a multiplexer 124 that is controlled by a lock detector 130 . The lock detector 130 causes the multiplexer 124 to initially couple the output of the input buffer 120 to a clock tree 140 , which, in turn, is coupled to an internal data or “DQ” path 144 . Once the measurement delay line 116 has set the proper delay of the variable delay line 118 , the lock detector 130 causes the multiplexer 124 to couple the output of the SMD/CSD circuit 114 to a latch (not shown) in the tree 140 , which, in turn, strobes data through a signal line 142 and through the DQ path 144 . As previously mentioned, it requires only two periods of the external clock XCLK signal for the proper delay of the variable delay line 118 to be set. Thus, the lock detector 130 can be implemented by a conventional circuit that simply counts two clock pulses and then generates a signal to switch the multiplexer 124 .
[0021] Unlike the clock skew compensation circuits 50 shown in FIG. 2, the clock skew compensation circuit 110 does not use any circuit to model the delay of the clock tree 140 . Instead, the delay of the clock tree is determined from the clock tree 140 itself. More specifically, a feedback signal from a chosen node of the clock tree 140 is coupled through a line 148 to the input of the measurement delay line 116 through a delay model circuit 150 . However, the delay model circuit 150 does not model the delay of the clock tree 140 . Instead, the delay model circuit 150 models only the delay d 1 of the input buffer 120 and the DQ path 144 . As previously explained, it is substantially easier to model a clock driver or a single data path than it is to model a clock tree. In the clock skew compensation circuit 110 , the delay model circuit 150 is implemented by a “dummy” input buffer 154 , which is identical to the input buffer 120 , and an additional delay circuit 155 , which provides a delay corresponding to the delay of the DQ path.
[0022] The delay of the clock tree 140 from the output of the SMD/CSD circuit 114 to the chosen node can be designated as d 3 . Since the feedback signal coupled to the input of the delay model circuit 150 corresponds to the delay of the clock tree 140 , the signal applied to the input of the measurement delay line 116 corresponds to the delay of the input buffer 120 plus the delay of the clock tree 140 . The signal applied to the measurement delay line 116 thus replicates the signals that the delay model circuits provide to the measurement delay lines in the clock skew compensation circuits 50 shown in FIG. 2.
[0023] The equations explaining the operation of the clock skew compensation circuit 110 are as explained below with the assumption that n=1 and d mdl <tCLK. As previously mentioned, d 1 is the delay of the input buffer 120 , d 2 is the delay of the delay of the SMD/CSD circuit 114 , d 3 is the delay of the clock tree 140 to the node where the feedback signal is taken, and d 4 is the delay of the DQ path 144 : The delay d 2 of the SMD/CSD circuit 114 is given by the equation d 2 =tCLK-d 1 −d 3 −d 4 . Substituting this equation in the earlier equation provides: d 1 +[tCLK−d 1 −d 3 −d 4 ]+d 3 +d 3 , which may be expanded to d 1 +tCLK−d 1 −d 3 −d 4 +d 3 +d 4 , which can be simplified to tCLK, or one period of the external clock signal XCLK. The total time to achieve lock is given by the formula d 1 +d 3 +d mdl +(tCLK−d 3 −d mdl )+(tCLK−d 3 -d mdl )+d 3 +d 4 , which can be reduced to d 1 +2tCLK−d mdl +d 4 . Using the formula d mdl =d 1 +d 4 , the formula for calculating the total time to achieve lock can be reduced to simply 2tCLK.
[0024] The delay lines 116 , 118 used in the clock skew compensation circuit 110 of FIG. 3 may be implemented with series coupled logic circuits, such as inverters (not shown). In such case, the resolution of the delay lines 116 , 118 , i.e., the minimum delay increments, will be limited to the approximately 200 ps delay time of two logic gates. With time interpolation, the resolution chould be improved to a fraction of the two logic gate delay, such as about 50 ps. To allow the delay lines 116 , 118 to interpolate the delay time of each logic circuit, a clock skew compensation circuit 160 as shown in FIG. 4 may be used. The circuit 160 uses many of the same components used in the clock skew compensation circuit 110 of FIG. 3. In the interest of brevity, these components have been provided with the same reference numerals, and an explanation of their structure and operation will not be repeated. The clock skew compensation circuit 160 includes a DLL used to interpolate in fine increments within the minimum resolution of the delay lines 116 , 118 . The DLL includes a fine delay line 92 that can alter the delay of the clock signal applied to the clock tree in fine increments. The fine delay is incremented or decremented under control of an UP/DOWN signal generated by a phase detector 94 . The phase detector 94 compares the phase of the clock signal at the output of the input buffer 120 with the phase of the feedback clock signal from a predetermined node of the clock tree 140 . The compensation circuit 160 also differs from the compensation circuit 110 of FIG. 3 by the inclusion of a clock driver 170 for applying the internal clock ICLK signal to the clock tree 140 . Also, the compensation circuit 160 includes a latch 52 that uses the ICLK signal to capture an external DATA signal.
[0025] The following equation explain the operation of the clock skew compensation circuit 160 , in which d 1 is the delay of the input buffer 120 , d 2 is the delay of the SMD/CSD circuit 114 , d 3 is the delay of the fine delay circuit 92 , d 4 is the delay of the clock driver 170 , d 5 is the delay of the clock tree 140 to the node where the feedback signal is taken, and d 6 is the delay of the data driver circuit 56 . In order to balance the load of each output of the clock tree 140 , the feedback signal is coupled from the tree 140 through a signal line that is independent from, but has the same electrical length as, the signal lines used to couple the clock signal to other circuits, such as to the clock input of the latch 52 . The total delay from the external clock terminal where the external clock signal XCLK is applied to the clock input of the latch 52 is given by the formula: d 1 +d 2 +d 3 +d 4 +d 5 , where d mdl =d 1 -d 6 . The delay d 2 of each delay line 116 , 118 in the SMD/CSD circuit 114 is given by the equation d 2 =tCLK−d mdl −d 3 −d 4 −d 5 . Substituting the equations for d mdl and for d 2 in the total delay equation yields: d 1 +[tCLK−d 1 +d 6 −d 3 −d 4 −d 5 ]+d 3 +d 4 +d 5 , which can be simplified to tCLK+d 6 . The ICLK signal will thus be applied to the latch 52 one clock period after the DATA signal is applied to the latch 52 . The time to achieve lock can be calculated using the procedure describe above as: d 1 +d 6 +2[tCLK−d mdl −d 3 −d 4 −d 5 ]+[d mdl +d 3 +d 4 +d 5 ]+d 3 +d 4 +d 5 , which can be reduced to 2tCLK+d 6 .
[0026] Alternatively, rather than include the negative delay d 6 of the data input buffer 56 in the delay model circuit 150 , an additional input buffer (not shown) like the buffer 56 can be added between the input buffer 120 and the variable delay line 118 .
[0027] The clock skew compensation circuits 110 , 160 can be used to latch commands or addresses into and data into and out of a variety of memory devices, including the memory device shown in FIG. 5. The memory device illustrated therein is a synchronous dynamic random access memory (“SDRAM”) 200 , although the invention can be embodied in other types of synchronous DRAMs, such as packetized DRAMs and RAMBUS DRAMs (RDRAMS”), as well as other types of synchronous devices. The SDRAM 200 includes an address register 212 that receives either a row address or a column address on an address bus 214 . The address bus 214 is generally coupled to a memory controller (not shown in FIG. 5). Typically, a row address is initially received by the address register 212 and applied to a row address multiplexer 218 . The row address multiplexer 218 couples the row address to a number of components associated with either of two memory banks 220 , 222 depending upon the state of a bank address bit forming part of the row address. Associated with each of the memory banks 220 , 222 is a respective row address latch 226 , which stores the row address, and a row decoder 228 , which applies various signals to its respective array 220 or 222 as a function of the stored row address. The row address multiplexer 218 also couples row addresses to the row address latches 226 for the purpose of refreshing the memory cells in the arrays 220 , 222 . The row addresses are generated for refresh purposes by a refresh counter 230 , which is controlled by a refresh controller 232 .
[0028] After the row address has been applied to the address register 212 and stored in one of the row address latches 226 , a column address is applied to the address register 212 . The address register 212 couples the column address to a column address latch 240 . Depending on the operating mode of the SDRAM 200 , the column address is either coupled through a burst counter 242 to a column address buffer 244 , or to the burst counter 242 which applies a sequence of column addresses to the column address buffer 244 starting at the column address output by the address register 212 . In either case, the column address buffer 244 applies a column address to a column decoder 248 which applies various signals to respective sense amplifiers and associated column circuitry 250 , 252 for the respective arrays 220 , 222 .
[0029] Data to be read from one of the arrays 220 , 222 is coupled to the column circuitry 250 , 252 for one of the arrays 220 , 222 , respectively. The data is then coupled through a read data path to a data output register 256 , which applies the data to a data bus 258 . Data to be written to one of the arrays 220 , 222 is coupled from the data bus 258 through a data input register 260 and a write data path to the column circuitry 250 , 252 where it is transferred to one of the arrays 220 , 222 , respectively. A mask register 264 may be used to selectively alter the flow of data into and out of the column circuitry 250 , 252 , such as by selectively masking data to be read from the arrays 220 , 222 .
[0030] The above-described operation of the SDRAM 200 is controlled by a command decoder 268 responsive to command signals received on a control bus 270 . These high level command signals, which are typically generated by a memory controller (not shown in FIG. 5), are a clock enable signal CKE*, a clock signal CLK, a chip select signal CS*, a write enable signal WE*, a row address strobe signal RAS*, and a column address strobe signal CAS*, which the “*” designating the signal as active low. Various combinations of these signals are registered as respective commands, such as a read command or a write command. The command decoder 268 generates a sequence of control signals responsive to the command signals to carry out the function (e.g., a read or a write) designated by each of the command signals. These command signals, and the manner in which they accomplish their respective functions, are conventional. Therefore, in the interest of brevity, a further explanation of these control signals will be omitted. The CLK signal, shown in FIGS. 3 and 4 as the external clock signal XCLK, is preferably coupled through a clock skew compensation circuit in accordance with the invention, such as the clock skew compensation circuits 110 , 160 shown in FIGS. 3 and 4, respectively. The compensation circuits 110 , 160 can then be used to generate an internal clock signal ICLK that latches addresses from the address bus 214 , latches data from the data bus 258 , or latched data onto the data bus 258 , as previously explained.
[0031] [0031]FIG. 6 shows a computer system 300 containing the SDRAM 200 of FIG. 5. The computer system 300 includes a processor 302 for performing various computing functions, such as executing specific software to perform specific calculations or tasks. The processor 302 includes a processor bus 304 that normally includes an address bus, a control bus, and a data bus. In addition, the computer system 300 includes one or more input devices 314 , such as a keyboard or a mouse, coupled to the processor 302 to allow an operator to interface with the computer system 300 . Typically, the computer system 300 also includes one or more output devices 316 coupled to the processor 302 , such output devices typically being a printer or a video terminal. One or more data storage devices 318 are also typically coupled to the processor 302 to allow the processor 302 to store data in or retrieve data from internal or external storage media (not shown). Examples of typical storage devices 318 include hard and floppy disks, tape cassettes, and compact disk read-only memories (CD-ROMs). The processor 302 is also typically coupled to cache memory 326 , which is usually static random access memory (“SRAM”), and to the SDRAM 200 through a memory controller 330 . The memory controller 330 normally includes a control bus 336 and an address bus 338 that are coupled to the SDRAM 200 . A data bus 340 is coupled from the SDRAM 200 to the processor bus 304 either directly (as shown), through the memory controller 330 , or by some other means.
[0032] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
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A synchronized mirror delay circuit is used to generate an internal clock signal from an external clock signal applied to the synchronized mirror delay. The internal clock signal is then coupled through a clock tree, and a feedback signal is generated that is indicative of the propagation delay of the internal clock signal through the clock tree. The feedback signal is applied to the synchronized mirror delay to allow the synchronized mirror delay to delay the internal clock signal by a delay interval that compensates for the propagation delay in the clock tree. A lock detector may be used to initially generate the internal clock signal directly from the external clock signal. A fine delay circuit that delays the internal clock signal in relatively fine increments may be used to couple the internal clock signal to the clock tree.
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FIELD OF THE INVENTION
Background of the Invention
This invention is directed to a load sensing system for vehicles subjected to cantilever loading. The system is for the purpose of detecting the result of the sum of variable conditions which, through an infinite combination of weight, distance, height and vehicle attitude, can cause tipping of the vehicle with possible injury to the vehicle, to the load which it is carrying, to the operator, and to workmen and equipment in the vicinity of the loader vehicle. The system functions by detecting the result of the combination of conditions which may lead to tipping which manifests itself by lifting the load bearing wheels from the ground. The system functions to make the operator aware of the fact that the load has reached the limit of safe extension, and to render inoperative all controls which, if activated, could induce tipping.
One exemplary form of loader vehicle with which the sensing system of the present invention may be used is the high lift loader disclosed in Frederick et al U.S. Pat. No. 4,147,263, the disclosure of which is incorporated herein by reference. That loader is characterized by a fork lift or other load handling device carried at the end of an extendible telescopic boom, which in turn is carried by a longitudinally extendible transfer carriage supported in a frame carried by the vehicle axles. The frame is mounted for limited pivotal movement on a longitudinal axis so that the loader may be used on a slope or other non-level terrain. Extension and lifting of the load is accomplished by double acting hydraulic cylinders. It is easy to conceive of circumstances which, because of the weight of the load being carried, the distance it is extended forwardly of the vehicle, the height to which it is raised, and the attitude of the vehicle itself relative to level, may, if the operator does not exercise great care, cause the vehicle to tip. The present invention is directed to a system to alert the operator short of the critical tipping condition to inactivate his controls so that corrective action can be taken.
The Prior Art
No prior art is known which is directed to a mechanical system for preventing tipping of loader vehicles subjected to cantilever loading.
SUMMARY OF THE INVENTION
The invention is directed to a sensing system for a load carrying vehicle having a hydraulically controlled load carrier which is subjected to cantilever loading such that tipping of the vehicle may occur. A hydraulic system including double acting cylinders lifts and extends the load carrier. The vehicle includes a load bearing frame and an axle supporting that frame. The frame is mounted through a sub-frame assembly so as to be separable to a limited degree from the axle. The initiation of this separation signals the dangerous load condition. The sub-frame assembly includes a longitudinally extending deflection beam at one end through which the sub-frame assembly is securely fastened to the axle. At the opposite end of the sub-frame assembly, a tapered bolster plate is securely fastened to the vehicle axle and a pair of spaced apart movement limiting bars are secured to the sub-frame in engagement with the bolster plate. This secures the sub-frame to the axle but permits limited relative movement therewith. A load sensing device in the form of a mechanically actuated relief valve is disposed between the axle and the sub-frame assembly adjacent to the movable end of the sub-frame to detect the initiation of separation of the sub-frame from the axle. The sensing device is connected into the hydraulic system to disable further movement of the load carrier responsive to flow of hydraulic fluid from the sensing device to prevent further lifting or extension of the load which could induce tipping.
The load sensing device comprises a cylindrical housing having a pair of axially spaced apart hydraulic fluid ports in its wall for connection to the hydraulic system of the vehicle. The housing has a fixed bottom including an annular seal plate and a movable cover. A control piston is adapted for limited reciprocal movement in the housing. The top of the control piston is secured to the housing cover and the bottom normally engages the seal plate. The control piston includes a pair of axially spaced circumferential annular channels, each of which is in communication with one of the hydraulic fluid ports. A longitudinal channel within the control piston permits flow of fluid from the inlet channel to the outlet channel when the sensing device is operative to disable the load carrier controls. The control piston has a cylindrical recess in its top in which a smaller spring biased sensitive piston is adapted for limited reciprocal movement. This sensitive piston has an upward extension projecting in sealed relationship through a central opening in the housing cover. This upward extension engages the sub-frame while the sensing device housing rests on the axle. A fluid bleed passage permits continuous flow of a small amount of hydraulic fluid from the inlet channel through the sensitive piston recess to the outlet channel, as described more fully hereinafter.
The initial slight separation of the sub-frame assembly from the axle induced when the load being carried approaches tipping conditions permits the sensitive piston to be moved, which in turn permits the control piston to be moved so as to permit flow of hydraulic fluid to control means to disable the system against further extension of the load carrier, all as described fully hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated by the accompanying drawings in which corresponding parts are identified by the same numerals and in which:
FIG. 1 is an isometric view showing a load carrying sub-frame assembly of a mobile loader supported on the axle thereof;
FIG. 2 is an elevation of the axle and sub-frame assembly on the line 2--2 of FIG. 1 and in the direction of the arrows;
FIG. 3 is an end elevation on the line 3--3 of FIG. 1 and in the direction of the arrows showing engagement of the bolster plate and movement limiting bars;
FIG. 4 is a vertical section on an enlarged scale on the line 4--4 of FIG. 2 and in the direction of the arrows showing details of construction of the load sensing device in its normal at-rest position;
FIG. 5 is a similar section showing the sensing device in its operative position; and
FIG. 6 is a schematic illustration of a hydraulic system incorporating the sensing device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and particularly to FIGS. 1 through 3, there is shown the axle 10 of a load carrying vehicle subjected to cantilever loading. A sub-frame assembly, indicated generally at 11, is disposed on the top side of the axle. The sub-frame assembly is rectangular in form and includes a longitudinally extending horizontal deflection beam 12 securely fastened to axle 10, as for example by being welded to plate 13 and bolted by bolts 14 to plate 15 which is welded to the top surface of the axle 10. A pair of parallel spaced apart transverse horizontal beams 16 and 17 are welded at one end to deflection beam 12 and at the other to a longitudinally extending horizontal bolster beam 18. A plurality of braces 19-21 welded to the interior of the sub-frame insures a strong rigid assembly.
A longitudinally extending bolster thrust plate 22 is securely fastened to the axle at the end of the sub-frame opposite from the deflection beam 12. Bolster plate 22 is fastened, for example, by means of welding to a support plate 23 fastened by means of bolts 24 to a plate 25 welded to the top surface of axle 10. As seen in FIG. 3, the opposite ends 26 and 27 of the bolster plate taper upwardly and inwardly. The bottom ends of the bolster plate 22 are recessed to form shoulders 28 and 29. A pair of movement limiting bars 30 and 31 are securely fastened as by welding to the outside surface of bolster beam 18 of the sub-frame assembly. The inside edges of bars 30 and 31 taper upwardly and inwardly so as to engage the corresponding tapered ends 26 and 27, respectively, of the bolster plate 22 to transmit the weight of the sub-frame and the load which it carries to the bolster plate and axle. Each movement limiting bar has an inwardly projecting extension or hook tab 32 and 33, respectively, whose inside surfaces are positioned and adapted to engage bolster plate shoulders 28 and 29, respectively, to limit lifting movement of the sub-frame assembly and the load which it carries from axle 10. The frame of the loader may be pivoted relative to the vehicle wheels and axles on a longitudinal axis by mounting on a shaft or other suitable fittings journaled in the sub-frame assembly at 34 and 35.
When the cantilevered load being carried by the loader approaches tipping conditions, the positive rear axle load is reduced to near zero. Through the special mechanical means described, the sub-frame is enabled to slightly separate from the axle. Deflection beam 12 is so designed as to deflect slightly from the gravitational force acting on the free end of the axle during separation. The arrangement permits separation at negative axle load while locking the frame and axle together under normal operating conditions.
A sensor control device, indicated generally at 36, mounted between the sub-frame and axle, detects the slight separation of the sub-frame from the axle to activate appropriate valves to stop the flow of hydraulic fluid to any and all cylinder sides that further cantilever load while leaving the operator with control of fluid to retract or reduce cantilever. Under normal operating conditions, the sensor device is not subjected to any vehicle weight or load.
Referring now to FIGS. 4 and 5, the details of construction of the separation sensing device 36 are shown in normal at-rest and control disabling positions, respectively. The sensing device comprises a cylindrical housing 37 having a fixed bottom 38 and movable cover 39. A pair of axially spaced apart ports 40 and 41 adapted to receive fittings from hydraulic fluid inlet and outlet lines 42 and 43, respectively, extend through the housing wall.
An annular seal plate 44 is disposed in the bottom of the cylindrical chamber within the sensor housing. Seal plate 44 is desirably formed from a rigid but relatively soft and deformable material, such as a synthetic resinous plastic or aluminum, such that in the event that a metal chip or other foreign particle gains entrance to the cylinder, it may be forced to sink into the sealing surface so as not to otherwise hold the control piston 45 off its seat.
The control piston, indicated generally at 45, is positioned within the cylindrical chamber of the sensor housing for limited reciprocal movement. The control piston is provided with a first circumferential channel or inlet annulus 46 in direct fluid communication with inlet port 40 and an axially spaced apart circumferential channel or outlet annulus 47 in direct fluid communication with outlet port 41. A pair of annular grooves 48 and 49 spaced on opposite sides of circumferential channel 47 and fitted with O-rings 49 and 50, or similar seal rings, maintain a sliding seal between the control piston and cylinder wall. The top of the control piston is secured to cover 39 by a plurality of screws 52. The bottom of the control piston normally engages seal plate 44 in sealing engagement.
A central cylindrical recess 53 is formed in the top of control piston 45. A central axial aperture 54 extends from the bottom of the cylindrical recess to the bottom of the control piston. The upper end of aperture 54 is of larger diameter than the lower end so that a shoulder is formed at the juncture between the upper and lower ends of the aperture. A tubular sleeve is disposed in aperture 54 with a loose slide fit such that fluid may pass through the annular space between the sleeve and aperture. The top end of sleeve 55 is provided with an outwardly extending flange or collar 56, the bottom edge of which is adapted to engage the shoulder of aperture 54. Sleeve 55 is maintained rigidly secured to the sensor housing by means of a screw 57. The maximum length of the stroke of control piston 55 is determined by the distance between the sleeve collar 56 and the shoulder in aperture 54 when the control piston is in at-rest position. The collar limits the upward stroke of the control piston, a safety feature.
A longitudinally extending passage 58 from the bottom of the control piston to circumferential channel 47 permits flow of hydraulic fluid from inlet channel 46 to outlet channel 47 when the control piston is in its upper position, as seen in FIG. 5. Ordinarily this flow is blocked by virtue of the sealing engagement of the bottom of the control piston with sealing plate 44. Thus, the control piston functions as a valve preventing normal flow of hydraulic fluid from inlet line 42 to outlet line 43.
A smaller diameter sensitive piston 59 is disposed for limited reciprocal movement in recess 53 in the top of the control piston. Sensitive piston 59 is provided with a circumferential groove 60 in which is fitted an O-ring 61 or similar sealing ring to maintain sealing engagement between the piston 59 and wall of the cylindrical recess. An upwardly projecting height adjuster pad or piston extension member 62 extends through a central aperture in the housing cover 39 and engages the sub-frame. An O-ring 63 in a peripheral groove around the central opening maintains a sealing engagement between the member 62 and housing cover. The height adjuster pad or member 62 externally adjusts the height of piston 59 and permits a dirt/dust seal to be incorporated in the cover. Member 62 may be integral with the piston 59 but desirably is separate. The height of the height adjustment member 62 is such that when the sensor unit 36 is installed on a vehicle between the axle 10 and sub-frame assembly 11, the sensor unit is not subjected to any vehicle weight or load. However, when the sub-frame assembly begins to separate from the axle as a result of an excessive load, then, as explained hereafter, because of the force exerted on member 62 from within the sensor unit, member 62 moves upwardly in response to the frame separation activating the sensor control.
A plurality of recessed spring seats 64 (of which only one is shown) are uniformly spaced apart in the bottom of cylindrical recess 53 around aperture 54. Preferably four such recessed spring seats are provided. A compressed coil spring 65 is seated in each recess. The top end of each spring 65 extends into the cylindrical recess and engages the bottom surface of sensitive piston 59, the springs exerting upward force on the sensitive piston and downward force on the control piston.
A bleed hole 66 is provided between the circumferential inlet fluid channel 46 in the control piston and the cylindrical recess 53, in this instance through spring recess 64. Fluid line 42 is connected to a source of hydraulic fluid under pressure. A small percentage of this fluid passes through the bleed passage 66 and recess 64 into the bottom of recess 53. The bleed fluid thence passes through aperture 54 through the annular space between the aperture and sleeve 55 into longitudinal passage 58 into circumferential channel 47 and out through outlet line 43. This bleed fluid serves four functions simultaneously. First, it warms up the unit to increase responsiveness. Secondly, it exerts upward force on the sensitive piston 59 to cause the height adjuster or extension member 62 to move immediately in response to axle/frame separation. Thirdly, it creates a down force, always in proportion to inlet pressure, on the control piston to effect a better seal between the bottom of the piston and seal plate. Lastly, this same down force also temporarily cancels the up force generated in the inlet annulus 46.
In the operation of the sensing system, when the various load factors are such that tipping of the loaded vehicle is imminent, the positive rear axle load is reduced to near zero. Then the special mechanical means of the sub-frame assembly including the deflection beam 12, bolster plate 22, limiting bars 30-31 and hook tabs 32-33, permit limited separation of the frame from the axle. When this occurs, the height adjuster extension member 62 of the sensing control moves upwardly in response to the upward forces exerted upon sensitive piston 59, primarily by virtue of the upward force exerted by the bleed fluid and to a lesser extent by spring pressure acting under the sensitive piston. As the axle/frame separation occurs, the sensitive piston contacts the cover plate 39. At this moment, lockup occurs between the sensitive piston and the control piston 45. This cancels all down force on the control piston and enables up force created by the fluid pressure in the inlet annulus 46 to lift the control piston off its seat with seal plate 44 in proportion to the axle/frame separation. The full flow of fluid from the inlet 40 to the outlet 41 through passage 58 causes relief now to take place to stop all cantilever increasing fluid flow. Relief is maintained until the operator reduces cantilever force and regains positive axle loading.
As seen schematically in FIG. 6, the sensing unit functions basically as a mechanically actuated relief valve. Hydraulic lines serving double acting cylinders that promote cantilever loading are manifolded to the sensor inlet. When a load is in a configuration which maintains positive axle loading, no relief occurs. When positive axle loading nears zero, all fluid flow which would permit further extension of the load is disabled, but the operator is free to retract the load to correct the conditions tending to induce tipping.
When the axle and frame reunite, the sensitive piston 59 is forced downwardly to contact the control piston 45 and push it down. However, because there is an intended space to be maintained between the bottom of the sensitive piston and the cylindrical recess in the control piston, and bleed pressure is not occurring, the force exerted by the sensitive piston upon springs 65 pushes the control piston down to its seat in contact with the sealing plate and, at the same time, the springs push the sensitive piston upward to maintain frame contact. Bleed pressure is restored and the sensor unit is reactivated to detect the next incipient tipping episode.
Although the invention is described in terms of a sub-frame assembly disposed between a separate load-bearing main frame and the axle, the sub-frame assembly of course is part of the load bearing frame and bears the load of the main frame. In some installations the sub-frame assembly may be integral with the main frame with the deflection beam built into the main frame. The operation of the system remains precisely as described.
It is apparent that many modifications and variations of this invention as hereinbefore set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of example only and the invention is limited only by the terms of the appended claims.
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A sensing system for a load carrying vehicle having a hydraulically controlled load carrier which is subjected to cantilever loading such that tipping of the vehicle may occur. The vehicle includes a load bearing frame and an axle supporting that frame. The frame is mounted through a sub-frame assembly so as to be separable to a limited degree from the axle. The initiation of this separation signals the dangerous load condition. A load sensing device disposed between the axle and the sub-frame assembly detects the initiation of separation of the sub-frame from the axle. The sensor functions as a mechanically actuated relief valve in the hydraulic system by which cantilever loading is accomplished. Flow of hydraulic fluid from the sensing device functions to prevent further extension of the load which could induce tipping. Details of the sub-frame assembly and sensing device are disclosed.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application 61/291,592, filed Dec. 31, 2009, and is incorporated herein by reference.
GOVERNMENT RIGHTS
The present application was made with United States government support under Contract No. F33615-03-D-2357 awarded by the United States government. The United States government may have certain rights in the present application.
FIELD OF THE INVENTION
The present invention relates to gas turbine engines, and more particularly, to gas turbine engine frames.
BACKGROUND
Structures such as frames for gas turbine engines remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.
SUMMARY
One embodiment of the present invention is a unique gas turbine engine. Another embodiment is a unique frame for a gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and gas turbine engine frames. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
FIG. 1 schematically depicts a gas turbine engine having an intermediate frame in accordance with an embodiment of the present invention.
FIG. 2 is an exploded side view of an intermediate frame for a gas turbine engine in accordance with an embodiment of the present invention.
FIG. 3 is a cross section of the intermediate frame of FIG. 2 .
FIGS. 4A and 4B are end views of the intermediate frame of FIG. 2 .
DETAILED DESCRIPTION
For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nonetheless be understood that no limitation of the scope of the invention is intended by the illustration and description of certain embodiments of the invention. In addition, any alterations and/or modifications of the illustrated and/or described embodiment(s) are contemplated as being within the scope of the present invention. Further, any other applications of the principles of the invention, as illustrated and/or described herein, as would normally occur to one skilled in the art to which the invention pertains, are contemplated as being within the scope of the present invention.
Referring now to the drawings, and in particular, FIG. 1 , a non-limiting example of a gas turbine engine 10 in accordance with an embodiment of the present invention is depicted. Engine 10 includes a fan system 12 , an intermediate frame 14 , a compressor system 16 , a combustor 18 and a turbine system 20 . In one form, engine 10 is a multi-spool engine. In other embodiments, engine 10 may be a single spool engine or a multi-spool engine having any number of spools. In one form, engine 10 is a turbofan engine, wherein fan system 12 includes a plurality of fan stages (not shown). In other embodiments, engine 10 may be another type of gas turbine engine, such as a turbojet engine, a turboshaft engine or a turboprop engine, or a turbofan engine having only a single fan stage.
Fan system 12 is operative to pressurize air received into engine 10 , some of which is directed into compressor system 16 as core flow. The balance of the air pressurized by fan system 12 is directed into a bypass duct system (not shown) and discharged by turbofan engine 10 to generate thrust. In one form, fan system 12 includes two fan stages (not shown). In other embodiments, a greater or lesser number of fan stages may be employed.
Intermediate frame 14 is operative to direct air pressurized by fan system 12 toward compressor system 16 , and to transmit engine 10 mechanical loads to an engine mount system 22 , such as an intermediate engine mount. Although depicted as being disposed between fan system 12 and compressor system 16 , it will be understood that in other embodiments intermediate frame 14 may take other forms and/or may be located in other positions. For example, in other embodiments, intermediate frame 14 may be located between compressor 16 and combustor 18 ; between combustor 18 and turbine system 20 ; and/or may be considered a portion of compressor system 16 or turbine system 20 , and/or may house all or a portion of one or more of fan system 12 , compressor system 16 , combustor 18 and turbine system 20 .
Compressor system 16 is operative to compress the core flow discharged by fan system 12 . In one form, compressor system 16 includes two multi-stage compressors (not shown), each of which includes a plurality of blades and vanes in a plurality of stages for compressing air received by compressor system 16 . In other embodiments, compressor system 16 may be in the form of a single multi-stage compressor. In still other embodiments, compressor system 16 may include more than two compressors, e.g., a low pressure (LP) compressor, an intermediate pressure (IP) compressor and a high pressure (HP) compressor.
Combustor 18 is in fluid communication with compressor system 16 . Combustor 18 is operative add fuel and combust air pressurized by compressor system 16 .
Turbine system 20 is in fluid communication with combustor 18 . Turbine system 20 operative to expand the hot gases received from combustor 18 and to extract energy therefrom to drive compressor system 16 and fan system 12 . In one form, turbine system 20 includes two turbines, i.e., an LP turbine and an HP turbine. In other embodiments, a greater or lesser number of turbines may be employed. Each turbine includes one or more stages of blades and vanes.
Referring now to FIG. 2 , an exploded view of a non-limiting example of intermediate frame 14 is depicted and described. Intermediate frame 14 includes a metallic inner hub 24 , a metallic outer construction 26 , a composite flowpath 28 , a metallic flange 30 , a plurality of service tubes 34 , a plurality of metallic struts 32 and a plurality of strut caps 36 .
Metallic inner hub 24 is a structural component of intermediate frame 14 and houses, for example, a bearing sump and a gearbox, for which metallic inner hub 24 provides structural support. In one form, the bearing sump includes mainshaft bearings, such as rolling element bearings, that support all or part of one or more engine 10 rotors. Metallic inner hub 24 is formed of a metallic material, such as a titanium, aluminum or magnesium alloy.
Metallic inner hub 24 includes a plurality of strut pedestals 38 and a contoured outer surface 39 . Strut pedestals 38 extend outward from contoured outer surface 39 . In one form, strut pedestals 38 extend radially outward from contoured outer surface 39 . In other embodiments, strut pedestals may extend outward from contoured outer surface 39 in other fashions, e.g., tangentially from contoured outer surface 39 or tangentially from a reference diameter. Strut pedestals 38 are configured for engagement with service tubes 34 and metallic struts 32 . In one form, strut pedestals 38 and outer surface 39 are part of an integral unit forming metallic inner hub 24 . In other embodiments, strut pedestals 38 and/or outer surface 39 may be formed as separate components and assembled together to form metallic inner hub 24 . In one form, outer surface 39 is generally parallel to an inner flowpath wall inside intermediate frame 14 (e.g., inner wall 52 of composite flowpath 28 , described below). In other embodiments, outer surface 39 may form part of the inner flowpath surface.
Metallic outer construction 26 is formed of a metallic material, such as a titanium, aluminum or magnesium alloy. Metallic outer construction 26 is adapted to interface with strut caps 36 and with engine mount system 22 . Metallic outer construction 26 is operative to maintain the circumferential orientation of metallic struts 32 and service tubes 34 . Metallic outer construction is also operative to transmit engine 10 mechanical loads to engine mount system 22 .
Composite flowpath 28 is radially disposed between metallic inner hub 24 and metallic outer construction 26 . Composite flowpath 28 is formed of a composite material. In one form, the composite material is a carbon bismaleimide composite. A non-limiting example of a carbon bismaleimide composite is Cycom 5250-4 BMI, commercially available from Cytec Industries Inc., headquartered in Woodland Park, N.J., USA. Other composite materials may be used in other embodiments, e.g., including ceramic matrix composites, metal matrix composites, organic matrix composites and/or carbon-carbon composites. In one form, composite flowpath 28 is formed via a resin transfer molding (RTM) process. In other embodiments, other manufacturing processes and techniques suitable for use in manufacturing composites may be employed in addition to or in place of RTM. In one form, composite flowpath 28 has a cavity 42 adapted to receive metallic inner hub 24 .
Metallic flange 30 is adapted to interface with both composite flowpath 28 and with metallic inner hub 24 . Metallic flange 30 is operative to secure composite flowpath 28 to metallic inner hub 24 . Service tubes 34 and metallic struts 32 of intermediate frame 14 extend between metallic inner hub 24 , e.g., strut pedestals 38 , and outer construction 26 . Metallic struts 32 are formed of a metallic material, such as a titanium, aluminum or magnesium alloy. Engine mechanical loads, such as rotor loads, inertial loads and engine weight loads are reacted by metallic inner hub 24 for transmission to engine mount system 22 via strut pedestals 38 . Strut pedestals 38 transmit the mechanical loads from metallic inner hub 24 into metallic struts 32 .
Strut caps 36 are adapted to interface with, service tubes 34 and metallic outer construction 26 , and may also include interface features for connection to engine externals, such as tubing and a wiring harness. Metallic struts 32 transmit the mechanical loads to metallic outer construction 26 via strut caps 36 . The loads are transmitted from metallic outer construction 26 to mount system 22 .
Strut pedestals 38 and strut caps 36 are adapted to interface with service tubes 34 . Service tubes 34 , which may also be referred to as transfer tubes, provide passages between metallic inner hub 24 and metallic outer construction 26 for the provision of services to and from metallic inner hub 24 . For example, in some embodiments, service tubes 34 are structured to conduct one or more of pressurized lube oil, scavenge oil, seal charging air, sump vent air, cooling air, one or more sensors, one or more shafts, such as a tower shaft 40 for transmitting power to an accessory gearbox, and/or one or more communications links and/or power cables between metallic inner hub 24 and metallic outer construction 26 . The communications links include, for example, wired and/or optical links to transmit sensor data and/or control inputs, as well as wired links to transmit electrical power. In one form, service tubes 34 are fitted on either end into holes in metallic inner hub 24 and strut caps 36 , and are sealed, e.g., with an o-ring or gasket.
Referring now to FIGS. 3 , 4 A and 4 B, the exemplary intermediate frame of FIG. 2 is depicted as assembled. FIG. 3 is a cross section of intermediate frame 14 , and FIGS. 4A and 4B are end views of intermediate frame 14 .
Composite flowpath 28 is disposed radially between metallic inner hub 24 and metallic outer construction 26 . Composite flowpath 28 defines flowpaths for the working fluid of engine 10 . A flowpath is a passageway that channels bulk working fluid flow through engine 10 , i.e., core airflow and bypass airflow, as opposed to fluid passages that transmit relatively small quantities of fluids, e.g., cooling air, pressure balance air, vent air and seal charging air, such as service tubes 34 . As illustrated in FIG. 3 , composite flowpath 28 defines both a primary flowpath 46 and a secondary flowpath 48 . In other embodiments, a greater or lesser number of flowpaths may be defined by composite flowpath 28 . In one form, secondary flowpath 48 is disposed radially outward of primary flowpath 46 , although other arrangements may be employed in other embodiments. In one form, primary flowpath 46 is operative to conduct fan system 12 discharge flow to compressor system 16 , and secondary flowpath 48 is operative to conduct fan system 12 discharge flow as a bypass flow.
Composite flowpath 28 includes a composite primary flowpath outer wall 50 and a composite primary flowpath inner wall 52 spaced apart from outer wall 50 . Inner wall 52 is disposed radially inward of outer wall 50 . Outer wall 50 and inner wall 52 define primary flowpath 46 . Composite flowpath 28 also includes a composite secondary flowpath outer wall 54 and a composite secondary flowpath inner wall 56 spaced apart from outer wall 54 . Inner wall 56 is disposed radially inward of outer wall 54 . Outer wall 54 and inner wall 56 define secondary flowpath 48 .
Composite flowpath 28 includes a plurality of hollow composite struts 44 . Composite struts 44 are subdivided two groups: inner composite struts 44 A and outer composite struts 44 B. In one form, inner composite struts 44 A and outer composite struts 44 B are hollow. In other embodiments, some or all of inner composite struts 44 A and outer composite struts 44 B may be solid.
Composite struts 44 A extend between composite primary outer wall 50 and composite primary inner wall 52 . Composite struts 44 A are adapted to receive strut pedestals 38 , metallic struts 32 and service tubes 34 . Composite struts 44 B extend between composite secondary flowpath outer wall 54 and composite secondary flowpath inner wall 56 . Composite struts 44 B are adapted to receive metallic struts 32 and service tubes 34 . In one form, composite flowpath 28 is integrally formed as a unitary single piece structure, including outer wall 50 , inner wall 52 , outer wall 54 , inner wall 56 , and composite struts 44 A and 44 B. In other embodiments composite flowpath 28 may be in the form of discrete composite components that are assembled together.
Composite flowpath 28 and metallic inner hub 24 are adapted to interface and transmit aerodynamic loads on composite flowpath 28 to metallic inner hub 24 . For example, loads resulting from pressures and flows in primary flowpath 46 and secondary flowpath 48 are transmitted to metallic inner hub 24 . In addition loads resulting from the pressures in cavities of composite flowpath 28 , e.g., cavity 42 and a cavity 58 disposed between primary flowpath outer wall 50 and secondary flowpath inner wall 56 , are transmitted to metallic inner hub 24 . In one form, composite struts 44 A and strut pedestals 38 are adapted to jointly form an interface for transmitting aerodynamic loads from composite flowpath 28 to metallic inner hub 24 . In other embodiments, intermediate frame 14 may be configured to transmit aerodynamic loads from composite flowpath 28 to other structures, such as contoured outer surface 39 or a face of metallic hub 24 , one or more of metallic struts 32 and/or metallic outer construction 26 .
In one form, intermediate frame 14 is assembled by inserting inner metallic hub 24 into cavity 42 of composite flowpath 18 . Composite flowpath 28 is secured onto metallic inner hub 24 with metallic flange 30 . For example, in some embodiments, metallic flange 30 is bolted onto metallic inner hub 24 to clamp composite flowpath 28 between metallic inner hub 24 and metallic flange 30 . Metallic struts 32 and service tubes 34 are inserted into composite struts 44 for interface with metallic inner hub 24 , e.g., via strut pedestals 38 . Strut caps 36 are then installed over metallic struts 32 and service tubes 34 . Metallic outer construction 26 is then assembled over strut caps 36 and secured to strut caps 36 , e.g., using bolts (not shown).
Metallic inner hub 24 , metallic struts 32 and metallic outer construction 26 , as assembled, form a loadpath that transfers engine mechanical loads between metallic inner hub 24 and metallic outer construction 26 , and from metallic outer construction to engine mount system 22 . The loadpath passes through the metallic structures of intermediate frame 14 , and bypasses composite flowpath 28 . By being divorced from the loadpath, composite flowpath 28 does not require the strength of metallic materials, which allows the use of composite materials to form flowpath 28 , which may in some embodiments reduce the weight of intermediate frame 14 relative to similar structures formed solely or primarily of metallic materials.
Embodiments envisioned include a gas turbine engine frame, including a metallic inner hub; a metallic outer construction; and a composite flowpath disposed between the metallic inner hub and the metallic outer construction, the composite flowpath defining a primary flowpath for a working fluid of the gas turbine engine.
In a refinement, the gas turbine engine frame also includes metallic struts extending between the metallic inner hub and the metallic outer construction, wherein the metallic inner hub, the metallic struts and the metallic outer construction are assembled to form a loadpath to transfer engine mechanical loads between the metallic inner hub and the metallic outer construction. In another refinement, the loadpath bypasses the composite flowpath. In a further refinement, the gas turbine engine frame is structured to transmit aerodynamic loads from the composite flowpath to one of the metallic inner hub, the metallic struts and the metallic outer construction.
In another refinement, the composite flowpath is formed as a single piece structure.
In yet another refinement, the composite flowpath includes a composite inner flowpath wall and a composite outer flowpath wall spaced apart from the composite outer flowpath wall, and wherein the composite inner flowpath wall and the composite outer flowpath wall define the primary flowpath. In one form, the composite flowpath includes a plurality of composite struts, wherein at least a portion of each composite strut extends between the composite inner flowpath wall and the composite outer flowpath wall. In a refinement, the composite inner flowpath wall, the composite outer flowpath wall and the plurality of composite struts are integrally formed.
Embodiments also include a gas turbine engine, including a compressor; a turbine; and an engine frame, the engine frame including a metallic load-bearing structure and a composite flowpath, wherein the metallic load-bearing structure defines a loadpath operative to transmit engine mechanical loads to an engine mount of the gas turbine engine, and wherein the composite flowpath is divorced from the loadpath.
In a refinement, the composite flowpath defines a primary flowpath for a working fluid of the gas turbine engine. In a further refinement, the composite flowpath includes a primary flowpath outer wall and a primary flowpath inner wall disposed radially inward of the primary flowpath outer wall, wherein the primary flowpath outer wall and the primary flowpath inner wall define the primary flowpath.
In another refinement, the composite flowpath further defines a secondary flowpath for the working fluid of the gas turbine engine. In one form, the composite flowpath includes a secondary flowpath outer wall and a secondary flowpath inner wall disposed radially inward of the secondary flowpath outer wall, and wherein the secondary flowpath inner wall and the secondary flowpath outer wall define the secondary flowpath. In a refinement, the composite flowpath includes a composite strut extending through the secondary flowpath. In another refinement, the metallic load-bearing structure includes a metallic strut disposed within the composite strut, wherein the metallic strut is operative to transmit the engine mechanical loads through the secondary flowpath.
In another refinement, the metallic load-bearing structure includes a metallic inner hub disposed radially inward of the composite flowpath; a metallic outer construction disposed radially outward of the composite flowpath; and a metallic strut extending between the metallic inner hub and the metallic outer construction.
In yet another refinement, the gas turbine engine includes a service tube extending between the metallic inner hub and the metallic outer construction, wherein the service tube is structured to conduct between the metallic inner hub and the metallic outer construction at least one of pressurized lube oil; scavenge oil, seal charging air; sump vent air, cooling air, a sensor, and a communications link. In one form, the composite flowpath includes a composite strut disposed at least partially around the service tube. In one form, the composite flowpath is formed as a single piece structure.
In still another refinement, the composite flowpath includes a composite strut disposed at least partially around the metallic strut.
Embodiments also include a gas turbine engine, including a compressor; a turbine; and an engine frame, the engine frame including composite means for defining a primary flowpath for a working fluid of the gas turbine engine; and means for transmitting engine mechanical loads to an engine mount of the gas turbine engine, wherein the composite means are divorced from the engine mechanical loads.
In a refinement, the engine frame also includes composite means for defining a secondary flowpath for the working fluid of the gas turbine engine.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.
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One embodiment of the present invention is a unique gas turbine engine. Another embodiment is a unique frame for a gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and gas turbine engine frames. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to assemblies comprising stacks refills containing elements such as pipette cones.
2. Background of the Invention
An assembly of this type is known comprising a series of stacked trays each carrying pipette cones, the trays being enclosed in a case of transparent material in the form of a tower that is closed at its top end. The tower can receive a loader at its bottom end, thereby temporarily fixing the trays of the stack to one another. Since the trays are placed one on another in the stack, it is necessary to turn the tower upside-down to place the loader at its top end in order to prevent the trays and the cones becoming dispersed. It is only afterwards that the tower can be put back the right way up. The loader is in turn mounted on a rack or carrier. With the stack and the loader received in this way on the rack, the assembly is arranged in such a manner that downward pressure on the stack causes it to move downwards and a tray to be loaded onto the rack. Thereafter the rack is removed from the loader and the stack to give access to the pipette cones of the tray thus received on the rack. That type of tower has the advantages of being relatively simple to operate, that it saves space for storing the trays and thus the cones, and that it avoids direct contact between the user and the trays or the cones, which could contaminate them. Nevertheless, the assembly is still relatively bulky and difficult to manipulate.
SUMMARY OF THE INVENTION
An object of the invention is to provide a refill assembly that is simpler to manipulate and that is more compact.
To achieve this object, the invention provides an assembly for elements, in particular pipette cones, the assembly comprising at least two refills suitable for forming a stack and carrying elements, loader means for receiving the stack and separating one of the refills from the remainder of the stack, and fixing means for fixing the refills to one another within the stack, wherein at least one of the refills comprises the fixing means.
Thus, since the refills are fixed directly to one another, there is no need to provide a rigid case containing the stack of refills. Under such circumstances, in the absence of such a case, the height of the stack decreases as the refills are used up. This gives rise to a considerable saving of space. The assembly nevertheless remains simple to manipulate.
Advantageously, the fixing means comprise fixing portions suitable for mutual male-female engagement.
Thus, the fixing means are compact.
Advantageously, the loader means are suitable for applying force to the fixing portions so as to disengage them.
Advantageously, on each refill, the fixing means comprise an orifice, and a catch suitable for engaging the orifice of another refill.
Advantageously, the loader means include a member suitable for applying force to the catch from a side of the orifice opposite from the catch.
Advantageously, the loader means are suitable for carrying the stack prior to unlocking the fixing means.
Thus, the stack is supported by the loader means before the user causes a refill to be released from the stack.
Advantageously, the loader means are suitable for carrying the remainder of the stack after the fixing means have been unlocked.
Thus, the remainder of the stack is supported separately from the released refill.
Advantageously, the loader means are suitable for carrying the stack or the remainder of the stack via a single refill.
Advantageously, the assembly includes fixing means for fixing the stack to the loader means, in particular prior to the refill fixing means being unlocked.
Thus, it is easy to move the assembly without running the risk of causing it to fall apart.
Advantageously, the stack fixing means are suitable for fixing a single refill of the stack to the loader means.
Advantageously, the assembly includes fixing means for fixing the remainder of the stack to the loader means, in particular after the refill fixing means have been unlocked.
Thus, it is easy to access the released refill without causing the remainder of the stack to come apart.
Advantageously, the fixing means of the remainder of the stack are suitable for fixing a single refill of the remainder of the stack to the loader means.
Advantageously, the assembly includes centering means for centering the stack on the loader means.
This makes them easier to assemble.
Advantageously, the loader means comprise at least one portion in relief that is movable between a locking position in which it prevents relative displacement of one of the refills and a transfer position in which it allows such displacement.
Advantageously, the assembly includes return means for returning the portion in relief into the locking position.
Advantageously, the portion in relief is suitable for being moved from the locking position to the transfer position under the effect of the portion in relief being subjected to a force from the refill.
Thus, the refill is released under the effect of the user applying a force in this direction to the assembly, thereby reducing the risk of the refill being released in untimely manner.
Advantageously, the loader means are suitable for unlocking the refill fixing means when the refill is in an in-use position for the elements.
Thus, unlocking to separate a refill is automatic. Having the refills fixed directly in one another therefore does not prevent the assembly being simple to manipulate.
Advantageously, the loader means are suitable for unlocking the refill fixing means under the effect of the stack moving relative to the loader means.
Advantageously, the loader means comprise a receptacle suitable for receiving one of the refills in an in-use position for the elements after the refill has been separated from the stack.
Advantageously, the assembly includes centering means for centering one of the refills on the receptacle.
This facilitates transfer of a refill onto the receptacle.
Advantageously, the loader means comprise a loader suitable for receiving the stack, and a receptacle suitable for receiving one of the refills in the in-use position for the elements from the loader.
Advantageously, the assembly includes means for centering the loader on the receptacle.
Advantageously, the receptacle is suitable for receiving the refill from the loader under the effect of the stack moving relative to the loader mounted on the receptacle.
Advantageously, the assembly is arranged in such a manner that the stack provides greater resistance to said movement when the loader is separate from the receptacle than when it is mounted on the receptacle.
This reduces the risk of a refill being released in untimely manner from the stack while the loader is not received on the receptacle.
Advantageously, the receptacle is suitable for unlocking the fixing means.
Advantageously, for the portion in relief belonging to the loader, the receptacle is suitable for placing the portion in relief in an intermediate position between the locking position and the transfer position, or in the transfer position, when the loader is received on the receptacle.
Thus, the position of the loader on the receptacle makes it easier to release the refill. This reduces the risk of release occurring outside the receptacle without making it more difficult to release a refill on the receptacle.
Advantageously, the assembly is arranged in such a manner that when the loader is not received on the receptacle, one of the refills co-operates by a camming effect with the loader so as to tend to hold the portion in relief in the locking position when a force is applied to the stack in order to achieve said displacement.
Advantageously, the portion in relief is secured to a tab extending in an opening in a wall of the loader means, in particular of the loader.
Advantageously, the portion in relief is secured to a flexible wall of the loader means, in particular of the loader.
Advantageously, each refill comprises a tray and at least one rib parallel to the tray and projecting from a side face of the refill.
This rib can co-operate with the portion in relief for fixing and/or releasing the refill.
Advantageously, each refill comprises a tray and spacers suitable for supporting the tray on a plane support and at a distance therefrom.
Thus, the refill when separated from the stack can be used directly as a rack without needing to be associated with a rack specifically provided for that purpose, e.g. in the receptacle, as is the case in prior devices. This eliminates the problem which consisted in ensuring proper centering between the refill to be released and the receiving rack in order to obtain accurate coincidence of their respective orifices arranged in a matrix, where failure to obtain such centering would either prevent release from taking place or else cause the cones to be dispersed. Furthermore, since the receptacle no longer has to carry a rack to begin with, it can be used successively to receive refills carrying elements of different sizes. Finally, the racks can be designed so that they themselves constitute a stack which is closed at least in part, thereby causing the elements carried by at least some of the racks to be isolated from the outside. These elements are thus protected from the surroundings.
Advantageously, one of the orifice and the catch is contiguous with an edge of the tray.
Advantageously, the assembly is arranged in such a manner that receiving a refill in the in-use position on the receptacle causes the refill to be fixed rigidly to the receptacle.
Advantageously, each refill includes at least one catch suitable for co-operating with a portion in relief of the receptacle in order to achieve said rigid fixing.
Advantageously, the assembly includes a stand suitable for directly supporting the stack when the loader is carrying the stack and when the receptacle is not receiving the loader.
Advantageously, the receptacle includes a lid and a holder suitable for extending in register with elements of a rack received in the receptacle so as to prevent the elements from leaving the rack when the lid closes the receptacle, the holder and the lid having means for releasably securing the holder to the lid.
The invention also provides an assembly for elements, in particular for pipette cones, the assembly comprising at least one refill suitable for carrying elements and forming a stack with an identical refill, loader means for receiving the stack and for separating the refill from the remainder of the stack, and fixing means for fixing the refill to an identical refill in the stack, wherein the refill comprises the fixing means.
Other characteristics and advantages of the invention will appear further in the following description of two preferred embodiments given as non-limiting examples. In the accompanying drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cutaway perspective view of a first preferred embodiment of the assembly of the invention prior to loading a rack in the case;
FIGS. 2 and 3 are two views on a larger scale showing two details of FIG. 1;
FIGS. 4 and 5 are respectively a longitudinal section and a cross-section of the FIG. 1 loader;
FIG. 6 is a view half in longitudinal section and half in elevation showing the assembly of FIG. 1;
FIG. 7 is a view on a larger scale showing a detail of FIG. 6 with the deformed parts;
FIGS. 8 and 9 are views analogous to FIGS. 6 and 7 showing the FIG. 1 assembly after a rack has been loaded into the box;
FIG. 10 is a view half in side view and half in cross-section showing the assembly of FIG. 1;
FIG. 11 is a view analogous to FIG. 10 showing the assembly after a rack has been loaded;
FIG. 12 is a view on a larger scale showing a detail of FIGS. 10 and 11;
FIGS. 13 and 14 are perspective views of the FIG. 1 box respectively with a rack and without a rack;
FIG. 15 is a view half in elevation and half in cross-section of the box of FIG. 13;
FIG. 16 is a view half in cross-section and half side view of the box of FIG. 13;
FIG. 17 is a perspective view from below of a rack in a second embodiment;
FIG. 18 is a perspective view from above of the box in the second embodiment for co-operating with the rack of FIG. 17;
FIGS. 19 to 21 are fragmentary longitudinal section views respectively of the box of FIG. 18, of the rack of FIG. 17, and of the box receiving the rack;
FIGS. 22 to 24 are partially cutaway views respectively in perspective, in elevation, and in perspective showing the box of FIG. 18 of the second embodiment in its closed position and receiving a rack with a holder;
FIG. 25 is a perspective view of the FIG. 24 assembly with the box open;
FIG. 26 is a perspective view of the lid of the FIG. 22 box on its own;
FIG. 27 is a perspective view of the holder of FIG. 22 on its own;
FIG. 28 is a perspective view of a stand forming a portion of the second embodiment of the invention;
FIG. 29 is an overall view of the second embodiment received on the stand of FIG. 28; and
FIG. 30 is a view analogous to FIG. 29 that has been partially cut away.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the first embodiment of the invention, the assembly of FIG. 1 is designed to carry elements, and specifically pipette tips or cones 3 . The assembly comprises a plurality of refills 2 , in this case identical to one another, and specifically in the form of racks or carriers. It also comprises a receptacle, in this case in the form of a box 4 , and a loader 6 . The box and the loader constitute loader means.
The racks 2 are described first. Each rack comprises a generally plane tray 8 in the form of a plane rectangle. In conventional manner, the tray 8 presents orifices 14 disposed regularly in a matrix of rows and columns, adapted to receive the pipette cones 3 and to support them. More precisely, the tray 8 has a top face 10 and a bottom face 12 which are respectively slightly convex and slightly concave. This makes it easier to take the pipette cones 3 with a multichannel pipette by making it easier to engage the cones in a row successively on the respective channels of the pipette by an appropriate rocking motion of the user's hand.
The rack 2 has two longitudinal walls 16 and two transverse walls 18 extending perpendicularly to the general plane of the tray 8 , from the same face thereof, extending from its edges and giving the rack the general shape of a rectangular parallelepiped. At the junction between the tray and each longitudinal or transverse wall, the rack has a shaped shoulder 20 suitable for receiving the bottom free edges of the longitudinal and transverse walls of another rack 2 when two racks 2 are stacked directly one on another in corresponding positions, as shown in FIG. 1, with their trays 8 being parallel. Thus, the tray 8 of a lower rack in a stack penetrates a little way between the walls 16 , 18 of the rack above it. As a result, the two racks are centered and spaced apart relative to each other. In addition, the longitudinal walls 16 and transverse walls 18 of the two racks then extend continuously one from another, thereby isolating the cones 3 to some extent from the surroundings. The racks are thus suitable for being stacked on one another to make up a stack in the form of a tower which can have a height of ten to twelve racks before the cones start being used. To clarify the drawings, the stack shown in the figures has only four racks. The walls of each rack constitute spacers for supporting the rack on a plane support with the tray 8 of the rack extending at a distance therefrom.
The racks 2 have direct fixing means that emerge between one another in the stack, said fixing means being constituted by fixing portions suitable for providing male-female coupling for fixing the racks together. Specifically, with reference in particular to FIGS. 2, 3 , and 13 , each rack has two rectangular orifices 22 formed in the tray 8 in the middles of its transverse edges, contiguous with the shoulder 20 . In addition, each transverse wall 18 has in its middle, at its bottom free edge, a catch 24 extending towards the inside of the rack and suitable for engaging in the orifice 22 of the rack beneath it in the stack.
This catch has a plane bottom guide face 26 that slopes relative to the wall 18 carrying the catch and relative to the tray 8 , facing towards the bottom rack of the stack. The orifice 22 has a top edge designed to come into contact with the guide face 26 and presenting a top guide facet 24 that slopes relative to the tray 8 and to the adjacent end face 18 so as to be parallel to the guide face 26 of the catch. When two racks 2 are stacked one on the other, the guide faces 26 of the two catches 24 come into surface contact with the facets 28 of the corresponding orifices 22 , thereby forcing outwards each transverse wall 18 that carries a catch 24 so that the catch 24 can move past the edge of the orifice 22 . Because of the resilience of the material constituting the wall 18 , the catch 24 is then returned towards the orifice 22 so as to be received therein.
The edge of the orifice 22 contiguous with the bottom face 12 of the tray is sharp and male. The top end of the catch 24 has a top shaped female shoulder suitable for receiving the sharp edge. The sharp edge and the shoulder are arranged in such a manner that when the catch 24 is engaged in the orifice 22 , the racks can be separated only by forcing the catch 24 outwards.
Each rack has a rectilinear rib 30 parallel to the tray 8 and projecting from the outside face of each longitudinal wall 16 , contiguously with the shoulder 20 , and also has a rectilinear rib 32 parallel to the tray and extending from the outside face of each transverse wall 18 contiguously with the free bottom edge of said wall. The ribs 30 and 32 are suitable for co-operating with the loader and the box as explained below. Each rack 2 can be made as a single piece of plastics material.
The box 4 is described below. It has a plane bottom wall 36 , two longitudinal walls 38 , and two transverse walls 40 extending perpendicularly from the bottom wall to give the box the general shape of a rectangular parallelepiped. At their free top edges, the longitudinal walls 38 have respective setbacks 42 making it easier to take hold of a rack 2 housed in the box in order to extract it. The box 4 has a lid 44 generally in the form of a rectangular parallelepiped connected to the rear longitudinal wall 38 via hinges. With the lid in the closed position, the box isolates the rack contained inside the box from the outside.
The box has studs 46 , 47 extending parallel to one another parallel to the walls 38 , 40 , projecting from the bottom 36 of the box to a level close to the level of the free top edges of the walls. Six of the studs 46 are close to the center of the box (they are referred to as “central” studs) and the other six studs 47 extend close to the transverse walls 40 (they are referred as “peripheral” studs), two studs close to the vertical edges of each wall and a middle stud in the vicinity of the center of the wall 40 . The purpose of the central studs 46 is specifically to support the tray 8 of the rack via its bottom face 12 bearing on the studs when the rack is received in the box. The peripheral studs 47 come into contact with the inside faces of the transverse walls 18 and the longitudinal walls 16 of the rack to center it relative to the box. The two middle peripheral studs penetrate slightly into the respective orifices 22 , in particular to finish off centering.
The loader 6 is described below, in particular with reference to FIGS. 4 and 5. It has two longitudinal walls 50 and two transverse walls 52 that are generally parallel in pairs, giving it the general shape of a rectangular parallelepiped and defining two mouths. At their bottom free edges, the longitudinal walls 50 have respective setbacks 54 . The loader presents a general midplane that is perpendicular to its walls 50 and 52 and to its height direction, subdividing the loader into two portions, a top portion and a bottom portion, such that the length and the width of the top portion are smaller than the length and the width of the bottom portion. This difference in size is obtained by each of the walls 50 and 52 having a profile that is S-shaped. On the outside faces of the walls, the transition between the top and bottom portions is marked by a sloping facet 56 , whereas on their inside faces the transition is provided by a shoulder forming a plane facet 58 perpendicular to the walls and facing downwards. The length and the width of the inside volume of the bottom portion are large enough to enable it to be engaged on and around the box 4 , unlike the dimensions of the top portion. When the loader 6 is mounted in this way on an open box 4 , the inside faces of the walls 50 and 52 of the bottom portion face the outside faces of the walls 38 and 40 of the box. The loader then bears against the free top edges of the walls of the box via its facet 58 , or alternatively it bears against studs projecting therefrom.
The inside faces of the bottom portion have ribs 60 extending parallel to the height of the loader for the purpose of bearing against the outside faces of the walls 38 and 40 of the box so as to contribute to centering the loader on the box. The ribs 60 are chamfered at their bottom ends so as to facilitate engaging the loader on the box.
The means providing co-operation between the loader 6 and the rack 2 are described below. Each longitudinal wall 50 of the loader has catches 70 , in this case two such catches, projecting from the inside face of the wall. Each catch 70 has its tip extending downwards. It is designed to enable a rack 2 to move downwards relative to the loader while preventing it subsequently from moving upwards. Each catch 70 has a plane top face 72 facing upwards, sloping downwards away from its top edge on the inside face and inwards towards the inside of the loader. The catch then continues downwards with a plane lower face 74 extending perpendicularly to the longitudinal inside face. Each catch 70 is contiguous to the top edge of the wall 50 and is located halfway between the longitudinal middle of said edge and a respective one of its ends.
When a stack of racks 2 is inserted into the top mouth of the loader, the longitudinal ribs 30 of the rack situated at the bottom end of the stack bear against the sloping top faces 72 of the catches 70 . The four catches 70 are suitable for supporting the stack in this position which is referred to as the “topmost” or “unfixed high” position, the rack or the stack of racks still being capable at this stage of being extracted upwards from the loader. Each of the longitudinal walls 52 of the top portion of the loader has two vertical ribs 76 projecting from the inside face of said wall. The ribs 76 contribute to spacing and centering the bottom rack of the stack in the loader, by bearing against the longitudinal ribs 32 of the rack. These ribs 76 have chamfered top ends so as to facilitate insertion of the rack 2 or the stack into the loader.
Each of the longitudinal walls 50 in the top portion of the loader has a rectilinear rib 78 of triangular profile extending horizontally and projecting from its inside face beneath the catches 70 , in register with the gap between them, but not in register with them. This rib 78 has sloping top and bottom faces respectively facing upwards and downwards.
Each of the transverse walls 52 in the bottom portion of the loader has two openings or holes 80 of rectangular shape into which there extend respective tabs 82 of corresponding shape. Each tab 82 is connected to the associated wall 52 via its top edge only, thereby allowing the tab 82 to move resiliently in bending through the opening 80 , both inwards and outwards relative to the loader 52 . When at rest, each tab 82 lies in the thickness of the wall. The outside face of the tab has an S-shape identical to that of the wall.
Each tab 82 has a catch 84 extending towards the inside of the loader projecting from the inside face of the transverse wall 52 when the tab is in its rest position. The catch 84 has two upper ribs 86 spaced apart from each other and facing each other at the same height, each having a top chamfer. The two ribs 86 could be replaced by a chamfer and a vertical face (which amounts to filling the empty space between the two ribs 86 with material). The catch 84 also has a horizontally shaped tip 88 extending inwards, projecting from the ribs 86 and sloping slightly upwards when the tab is in its rest position.
Starting from the above-mentioned topmost position, a small force urging the stack of racks downwards causes the racks 2 to move down to a “high” or a “fixed high” position. During this downwards movement, the longitudinal ribs 30 of the bottom rack of the stack force the catches 70 on the longitudinal wall of the loader outwards by forcing the longitudinal walls 50 that carry them to deform elastically outwards so as to allow the ribs to go past. Once they have gone past, the longitudinal ribs 30 of the rack bear against the two longitudinal ribs 78 of the loader and co-operate in centering therewith, and the transverse ribs 32 of the rack bear against the tips 88 of the catches 84 . The longitudinal ribs 78 of the rack and the tips 88 of the catches prevent further downwards movement of the stack in the absence of force being applied by the user. In addition, the longitudinal catches 70 of the loader prevent the longitudinal ribs 30 of the rack from allowing the rack to move back upwards relative to the loader. The stack of racks 2 is thus fixed to the loader 6 solely via the rack that is situated at the bottom end of the stack. The subassembly can thus be manipulated in any direction quite freely without running the risk of the racks coming apart. The assembly of the invention advantageously has a rack cover 90 that is identical to the racks 2 in all features except that its tray 8 does not have any orifices 14 for receiving cones and does not have any fixing orifices 22 . When fixed via its catches 24 to the top rack in the stack, it serves to protect the cones of that rack and to hold these cones in their orifices 14 . When the above-mentioned subassembly is provided with this cover 90 , it can be turned in any direction without running the risk of losing any cones. This position of the loader and of the stack is shown in FIGS. 1, 2 , 3 , 6 , 7 , 10 , and 12 . In this fixed high position, the subassembly with the loader can be removed from the box 4 or can be replaced thereon.
It is assumed below that the subassembly with the loader is received in the high position on the box that does not have a rack, as shown in FIG. 1 . The tabs 82 of the loader have chamfers 91 at their bottom ends that face downwards and that are defined either by a face of the tab or by ribs thereon as shown, said chamfers projecting from the inside face of the transverse wall 52 when the tab is in its rest position. These chamfers 91 can be seen more particularly in FIGS. 4, 5 , 7 , and 9 . When the loader 6 is engaged on the box 4 , the chamfers 91 come into contact with the free top edges of the transverse walls 40 of the box and thus act as cams for forcing the respective tabs 82 outwards. This outwards movement causes the tip 88 of the catch 84 of each tab to move away from the rack, which rack continues to be supported by the internal longitudinal ribs 78 of the loader. Thus, the bottom rack is no longer supported by the catches 84 . In addition, the position of the catch then allows the stack to move downwards on application of a force that is much less than that which would be needed in the absence of the box. In this respect, it is specified that FIG. 2 shows the parts assembled together but not deformed even though the tab in this position is normally deformed so that the catch 88 leaves a clear path for the rack. In addition, in this position, the central and peripheral studs 46 and 47 of the box already extend very slightly between the walls of the bottom rack. In particular, the middle peripheral studs 47 have their top ends bearing against the sloping bottom faces 26 of the transverse catches 24 of the rack so as to cause them to start moving apart, i.e. outwards as shown in FIG. 2 . The ribs 60 serve to center the loader 6 (and thus the outline of the rack) relative to the box 4 .
When the user forces the stack of racks downwards, e.g. by pressing on the top of the stack, the longitudinal ribs 30 of the bottom rack force the longitudinal ribs 78 of the loader to move apart together with the walls 50 carrying them, thereby enabling the rack to move downwards until it is received in the box. During this movement, the middle peripheral studs 47 move the catches 24 of the bottom rack further outwards by the camming effect of the ramps at the ends of the studs engaging the faces 26 of the catches. Immediately before the bottom rack is received so that it bears against the central studs 46 of the box, the top ends of the middle peripheral studs 47 come to bear via the inside of the bottom rack through the corresponding orifices 22 with the catches 24 associated with the next rack up in the stack. The stud 47 bears against the bottom face 26 of the catch, thereby urging it outwards by a camming effect. This outwards movement is sufficient to disengage the catch 24 of the next rack up from the orifice 22 of the rack that is about to be received in the box. This unlocks the rack fixing means.
As the stack moves downwards, the next rack up takes up the fixed high position. Once the downwards movement has come to an end, the central studs 46 prevent any further downwards movement of the stack. The subassembly comprising the remainder of the stack and the loader 6 fixed thereto can then be removed from the box 4 . This operation gives access to the rack 2 received in the box and above all to its cones 3 which can then be used directly.
After the cones have been used, it suffices to remove the rack 2 from the box, to replace the subassembly on the box, and to load a new full rack in the box by using the same operations of forcing the stack downwards. The same operations can be repeated until the last rack of the stack which, once in the box, leaves the cover 90 on its own in the loader 6 .
As shown in FIG. 2, each rack can, at each location of its bottom edge that is to come into register with the catch 88 , present a bottom sloping ramp face 91 facing towards the inside of the rack and suitable for coming into surface contact with an associated sloping top ramp face 93 of the catch 88 and facing towards the transverse wall 52 of the loader carrying the tab 82 . Thus, when the loader is supporting the stack of racks without being received on the box but standing on a work surface, the two ramp surfaces 91 and 93 come mutually into contact. Thus, under the effect of gravity or of untimely thrust from a user, the stack of racks tends to move downwards with the camming co-operation between the two faces 91 and 93 tending to move the catch 88 towards the inside of the rack, i.e. in the direction opposite to the direction that would allow the rack to be released when the loader is received on the box. This provides a safety feature that locks the stack of racks against moving down inside the loader whenever the loader is not received on a box.
The box whose dimensions are not tied to the dimensions of the cones 3 can be associated with stacks of racks 2 containing cones of different diameters.
As the racks are used up, the height of the assembly decreases, thereby saving space.
A second preferred embodiment of the invention is described below with reference to FIGS. 17 to 30 . The assembly is very similar to that of the first embodiment. Nevertheless, it incorporates a number of variants, which can indeed be implemented independently of one another.
In the assembly constituting the first embodiment, the rack 2 in its in-use position in the box 4 is fixed rigidly thereto by friction, in particular by the contact between the middle studs 47 and the transverse catches 24 . The rack is thus clamped to the box.
However, it is advantageous for such an assembly to be capable of being put into an autoclave while in this configuration. Typically, the autoclave includes a step of raising temperature to 121° C. over a period of 20 minutes. However, it has been found that under the effect of temperature rise, the plastics material of the rack softens and the rack deforms so that the clamping is reduced to nothing. After a period in the autoclave, the assembly cools down but its parts retain their deformation: there is no longer any clamping. Consequently, the rack is no longer fixed to the box and that gives rise to problems when users take cones or knock the box over.
The first of the variants described below seeks to mitigate that drawback. Each rack 2 comprises above each catch 24 another catch 101 that likewise projects inwards. The middle studs 47 for unlocking purposes present respective cavities 100 in their peripheral faces within which the corresponding catch 101 is received once the rack 2 has been received in the box 4 in the in-use position. The catch 101 is received in said cavity because of the resilience of the wall 18 which is elastically deformed immediately prior to the rack being received in the box. The cavity 100 forms an edge with which the catch 101 comes into engagement to prevent the rack 2 from being separated from the box unless a particularly large amount of force is exerted in this direction by the user. They are thus rigidly fixed together. In this position, the catch 101 can be received in the cavity, possibly without exerting force on the middle stud.
By means of such fixing, the assembly can be subjected to successive passages through an autoclave without degrading fixing between the rack and the box. Furthermore, in the above-described case where the catch 101 is received without applying force to the rack 2 , the passage through an autoclave does not give rise to any deformation. The assembly of the invention can thus be subjected to repeated passages through an autoclave.
Another variant incorporated in this embodiment consists in making at least one plane rib 102 parallel to the studs in the box and interconnecting some of them so as to reinforce them. Specifically, the rib 102 extends in a middle longitudinal plane of the box and interconnects the middle peripheral studs 47 .
Furthermore, as seen in the first embodiment, when the loader 6 supports the stack of racks 2 outside the box 4 , the stack of racks stands on the catches 88 and thus on the flexible tabs 82 . Unfortunately, in the event of an impact, it can happen that the stack of racks exerts sufficient force on the tabs as to cause at least one of the tabs to break.
A variant incorporated in the second embodiment seeks to mitigate that drawback. To this end, the assembly constituting the second embodiment includes a stand 106 shown in FIGS. 28 to 30 . The stand is made as a single part. It presents a central body 108 of shape and dimensions close to those of a rack 2 except that it does not have a tray between the top edges of its walls, but in contrast it does have a bottom 110 between their bottom edges.
The rectangular top edge 112 of this central body is suitable for directly supporting the bottom edge of the rack 2 at the bottom of the stack. For this purpose it has cutouts, in particular for providing a volume for receiving the catches 24 of the rack. The stand 106 also has a rectangular peripheral collar 112 surrounding the central body 108 at a distance therefrom, and of slightly smaller height. The central body 108 converges slightly in an upward direction while the collar 112 flares slightly in that direction. The stand 106 is designed to be suitable for receiving the loader 6 supporting a stack of racks after it has been removed from the box 4 , as shown in FIGS. 29 and 30. For this purpose, the loader 6 is placed on the stand 106 by inserting its walls between the central body 108 and the collar 112 . On penetrating into the loader, the central body comes into contact with the bottom edge of the bottom rack 2 of the stack that it is supporting. Under such circumstances, the tabs 82 of the loader are no longer carrying the stack of racks. The stack of racks can thus accommodate considerable impacts without running any risk of damaging the loader. The loader 6 together with the stack can then subsequently be taken freely from the stand 106 and put back on the box 4 .
To fix the stand 106 to the loader 6 in the position of FIG. 29, the collar 112 has fluting 114 to form ribs of semicircular cross-section on the inside face of the collar. When the loader 6 is placed on the stand 106 , the walls of the loader are jammed between the fluting 114 and the central body 108 . This provides a friction connection between the loader and the stand. Specifically, some of the fluting is located so as to extend in register with the tabs 82 .
Furthermore, the assemblies in both embodiments of the invention are designed to be suitable for receiving pipette cones of different models, in particular cones with a variety of collar heights, where the term “collar” is used for the larger portion of the cone that extends above the tray of the rack while the cone is being carried by a rack.
In the first embodiment, in order to place high-collar cones in the box, it is necessary to provide sufficient space between the curved surface of the rack (against which the collars bear) and the end wall of the lid. Under such circumstances, when small-collar cones are placed in the box, should the user for any reason happen to overturn the box (e.g. while putting it in an autoclave), then the cones escape from their housings. On opening the box, the user will find cones that are disposed in a jumble and that are thus unusable.
In the second embodiment, a variant is incorporated that seeks to remedy that drawback. Thus, with reference to FIGS. 22 to 27 the assembly constituting the second embodiment has a holder 120 comprising a flat rectangular body 121 presenting orifices 122 . Overall, the body has the same shape and the same dimensions as the top tray 8 of the racks 2 . The holder 120 has struts 124 projecting from its transverse edges, e.g. two such struts, suitable for engaging in blind orifices 126 in the transverse walls of the lid 44 so as to secure the holder in releasable manner to the lid. These orifices 126 extend in this case close to an edge of the lid that is a bottom edge when the lid is in the closed position. The struts 124 therefore slope.
The holder also has spacers 126 in the form of fingers extending from a plane face of the body 121 towards the end wall of the lid 44 so as to maintain a minimum spacing between the body 121 and the end wall of the lid.
When cones of low collar height are stored in the box, the holder 120 is mounted in the lid 44 . When the lid is closed, the body 121 comes into register with the collars in the immediate vicinity thereof and prevents them from escaping from the rack, even if the box is turned upside-down. If cones of greater collar height are to be stored, then it suffices to remove the holder 120 from the lid prior to closing it.
The box could be implemented with the holder independently of the characteristics of the tower of racks and independently even of the presence of a tower of racks.
Refills could be provided in the form of trays provided with legs having mutual fixing tabs.
Each of these elements comprising the loader, the box, and its lid can be made as a single piece, e.g. out of plastics material.
The assembly could be designed to carry other elements, e.g. ice cream cones.
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A number of racks make up a stack. An upper rack includes releasable catches received into orifices in the next lower rack to releasably attach the two racks to one another. A loader and receptacle cooperate with one another to release the bottommost rack from the stack and deposit it into the receptacle where pipette cones held therein are accessible for use. The bottom rack is placed into the loader where it is held by catches engaging ribs of the rack. The stack of racks with the loader attached is placed onto the receptacle. The stack of racks is pressed downwardly. The downward movement releases the bottom rack from the loader. At the same time, studs projecting up from the bottom of the receptacle engage catches of the second-from-the-bottom rack and free the bottom rack. The bottom rack now rests freely in the receptacle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. National Phase Application of PCT International Application PCT/JP2013/085163, filed Dec. 27, 2013 which claims priority to Japanese Application No. 2012-289043, filed Dec. 28, 2012, the contents of which are incorporated herein by reference in their entireties for all purposes.
TECHNICAL FIELD
The present invention relates to a bacterial cellulose and a bacterium producing it, and particularly to a bacterial cellulose excellent in dispersibility in liquids and a bacterium producing it.
BACKGROUND OF THE INVENTION
A bacterial cellulose typically consists of a nanofiber having a width of about 50 nm, and has received attention as a material capable of being utilized in various industrial fields since it has characteristics, such as high mechanical strength and biocompatibility and biodegradability. The bacterial cellulose is typically obtained in the form of a film consisting of a gelled substance (hereinafter, referred to as “gelled film”) on the culture medium surface by subjecting a bacterium, such as an acetic acid bacterium, to stationary culture; however, the gelled film has a problem, such as being poorly applicable as an actual material since it is poor in moldability and miscibility with other substances when applied to materials and high in cost because of being low in production efficiency.
To address such a problem, there is a need for a bacterial cellulose not in the form of a gelled film but dispersible in liquids and therefore excellent in applicability. For example, Non Patent Literature 1 discloses a bacterial cellulose obtained by subjecting Acetobacter xylinum subsp. sucrofermentans to aerated and agitated culture, and Non Patent Literature 2 also discloses a bacterial cellulose obtained by subjecting Gluconacetobacter xylinum strain JCM10150 to rotary shaking culture in a culture medium containing carboxymethyl cellulose (CMC).
CITATION LIST
Non Patent Literature
Non Patent Literature 1: Yoshinaga, et al., Kagaku To Seibutsu (Chemistry and Biology), vol. 35, no. 11, p. 7-14, 1997
Non Patent Literature 2: S. Warashina, et al., 2010 Cellulose R&D Abstracts at the 17th Annual Meeting of the Cellulose Society, p. 98, 2010
SUMMARY OF THE INVENTION
Technical Problem
However, the bacterial cellulose described in Non Patent Literature 1 is not high in dispersibility in water as is evident from the description that it is not one produced using a culture medium containing CMC having the effect of improving the dispersibility of a bacterial cellulose and that it is dispersed “in the form of tiny grains or fibers” in water (ibid; page 9, right column). Consequently, the bacterial cellulose is insufficient in terms of moldability and miscibility with other substances for practical use. The bacterial cellulose described in Non Patent Literature 2 is also not high in dispersibility in water since water containing the bacterial cellulose is higher in white turbidity at the bottom than at the top and has sedimentation observed and cellulose grains are visibly large (ibid; FIG. 1 ) in any of the cases where the amount of addition of CMC to the culture medium is 0.5%, 1%, and 2%. Consequently, this bacterial cellulose is insufficient in terms of moldability and miscibility with other substances, necessary for practical use.
Thus, the bacterial celluloses described in both of Non Patent Literatures 1 and 2 are insufficient in moldability as a material and miscibility with other substances, and also poor in practicability in terms of efficiency of material production.
The present invention has been made to solve such problems and an object thereof is to provide a bacterial cellulose high in dispersibility in liquids, favorable in moldability and miscibility with other materials in being put to practical use, and excellent in applicability as an actual material, and a bacterium producing the bacterial cellulose.
Solution to Problem
As a result of intensive studies, the present inventors have found that the bacterial cellulose is highly water-dispersible, which is obtained by subjecting the strain SIID9587 as a new strain of Gluconacetobacter intermedius (accession number NITE BP-01495) (hereinafter, sometimes referred to as “strain NEDO-01 ( G. intermedius strain SIID9587)”) to agitated culture in a CMC-containing culture medium using a glycerol-containing by-product generated in producing a biodiesel fuel from vegetable oil (Bio Diesel Fuel By-product; BDF-B, waste glycerin), reagent glycerol, or molasses as a carbon source, thereby accomplishing the following inventions.
(1) The bacterial cellulose according to the present invention has the physical characteristic of a transmittance of light at a wavelength of 500 nm of water containing the bacterial cellulose at a final concentration of 0.1±0.006% (w/w) of 35% or more.
(2) The bacterial cellulose according to the present invention further has the physical characteristic of a retention volume of the peak top of the chromatogram in the gel permeation chromatography performed under the following conditions i) to vi) of from 2.5 mL inclusive to 3.0 mL exclusive:
i) column: a column 6.0 mm in inside diameter and 15 cm in length, packed with a methacrylate polymer having a particle diameter of 9 μm; ii) guard column: 4.6 mm in inside diameter and 3.5 cm in length; iii) column temperature: 35° C.; iv) feed flow rate: 0.07 mL/minute; v) eluent: a 40 to 42% (w/w) tetrabutylphosphonium hydroxide aqueous solution; and vi) final concentration of the bacterial cellulose in the eluent: 0.2% (w/w).
(3) The bacterial cellulose according to the present invention is preferably produced by the assimilation of BDF-B.
(4) The bacterial cellulose according to the present invention is preferably produced by the assimilation of 1 or 2 or more selected from the group consisting of sugar, a sucrose-containing by-product generated in producing sugar, and hydrolysates thereof, and isomerized sugar.
(5) The by-product is preferably molasses when the bacterial cellulose according to the present invention is produced by the assimilation of the sucrose-containing by-product generated in producing sugar.
(6) The bacterial cellulose according to the present invention may be one produced by Gluconacetobacter intermedius.
(7) The bacterial cellulose according to the present invention may be one produced by Gluconacetobacter intermedius strain SIID9587 (strain NEDO-01) (accession number NITE BP-01495).
(8) The bacterium according to the present invention is characterized by producing the bacterial cellulose according to any one of (1) to (5) above.
(9) The bacterium according to the present invention may be Gluconacetobacter intermedius strain SIID9587 (strain NEDO-01) (accession number NITE BP-01495) producing the bacterial cellulose according to any one of (1) to (5) above.
Advantageous Effects of Invention
The bacterial cellulose according to the present invention can provide a bacterial cellulose almost uniformly dispersible in liquids such as water, and can contribute to an improvement in the quality of the final product and production efficiency or a reduction in production cost since this bacterial cellulose is excellent in moldability and miscibility with other substances. The present invention can provide a bacterial cellulose almost uniformly dispersible in liquids by purification under mild conditions without requiring steps of refining with a mixer and the like, and can provide a bacterial cellulose having a relatively large average molecular weight. In addition, the present invention can contribute to effective resource utilization by using a sucrose-containing by-product generated in producing sugar, such as BDF-B or molasses, as a carbon source, and enables the achievement of the reduction of bacterial cellulose price. Further, the present invention can efficiently provide a large amount of a bacterial cellulose by production using Gluconacetobacter intermedius or Gluconacetobacter intermedius strain SIID9587 (strain NEDO-01).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram showing a protocol for isolating a bacterium producing a bacterial cellulose by assimilating BDF-B. In the figure, the bacterial cellulose is abbreviated as BC.
FIG. 2-1 is a diagram showing points of identity and difference between the 16S rDNA nucleotide sequences of the strain SIID9587 and G. intermedius strain TF2. In the figure, the points of identity in the nucleotide sequences are represented by *marks and the points of difference are represented by quadrangular boxes. In the figure, G. intermedius indicates G. intermedius strain TF2.
FIG. 2-2 is a diagram showing points of identity and difference between the 16S rDNA nucleotide sequences of the strain SIID9587 and G. intermedius strain TF2. In the figure, the points of identity in the nucleotide sequences are represented by *marks and the points of difference are represented by quadrangular boxes. In the figure, G. intermedius indicates G. intermedius strain TF2.
FIG. 3 is a pair of tables showing bacteriological properties of the strain SIID9587.
FIG. 4 is a series of charts showing IR spectra of a bacterial cellulose obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to stationary culture (top chart) and products obtained by aerated and agitated culture using BDF-B and reagent glycerol as carbon sources (middle and bottom charts).
FIG. 5 is a series of photographs showing the appearance of waters each containing bacterial celluloses obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to aerated and agitated culture and stationary culture (left and middle) and a pulp-derived bacterial cellulose nanofiber (right).
FIG. 6 is a series of drawings showing the light transmittance at a wavelength of 500 nm of waters containing bacterial celluloses obtained by subjecting strain NEDO-01 ( G. intermedius strain SIID9587) to aerated and agitated culture using molasses and reagent glycerol as carbon sources, respectively, and the amount of the bacterial cellulose produced (amount of the BC produced) and the rate of production thereof (BC production rate).
FIG. 7 is a series of drawings showing the light transmittance at a wavelength of 500 nm of waters containing bacterial celluloses obtained by subjecting strain NEDO-01 ( G. intermedius strain SIID9587) and the known bacterial cellulose-producing bacteria G. hansenii strain ATCC23769 , G. xylinus strain ATCC53582 , G. xylinus strain ATCC700178 (BPR2001), G. xylinus strain JCM10150 , G. intermedius strain DSM11804, and G. xylinus strain KCCM40274 to aerated and agitated culture, and the amount of the BC produced, the BC production rate, and the BC production rate ratio.
FIG. 8 is a chart showing chromatograms of the gel permeation chromatography of a bacterial cellulose obtained by subjecting strain NEDO-01 ( G. intermedius strain SIID9587) to rotation culture using BDF-B as a carbon source (sample B), a pulp-derived cellulose nanofiber (pulp-derived CNF solution), and pullulan.
FIG. 9 is a pair of photographs showing the fiber widths and the transmission electron microscope-observed images of bacterial celluloses obtained by subjecting strain NEDO-01 ( G. intermedius strain SIID9587) to aerated and agitated culture (agitated-culture BC solution) and stationary culture (mixer-treated stationary-culture BC solution).
FIG. 10 is a pair of photographs showing the transmission electron microscope-observed images of a bacterial cellulose obtained by subjecting strain NEDO-01 ( G. intermedius strain SIID9587) to aerated and agitated culture (agitated-culture BC solution) and a pulp-derived cellulose nanofiber (pulp-derived CNF solution).
FIG. 11 is a pair of photographs showing the polarization microscope-observed images of a bacterial cellulose obtained by subjecting strain NEDO-01 ( G. intermedius strain SIID9587) to aerated and agitated culture (agitated-culture BC solution) and a pulp-derived cellulose nanofiber (pulp-derived CNF solution).
FIG. 12 is a graph showing the weight of bacterial celluloses obtained by subjecting strain NEDO-01 ( G. intermedius strain SIID9587) and the known bacterial cellulose-producing bacteria G. hansenii strain ATCC23769 , G. xylinus strain ATCC53582, and G. xylinus strain ATCC700178 (BPR2001) to stationary culture using reagent glycerol or BDF-B as a carbon source.
FIG. 13 is a graph showing the weight of bacterial celluloses obtained by subjecting strain NEDO-01 ( G. intermedius strain SIID9587) and the known bacterial cellulose-producing bacteria, the strain ATCC53582 and the strain ATCC23769, to shake culture using reagent glycerol or BDF-B as a carbon source.
DETAILED DESCRIPTION OF THE INVENTION
The bacterial cellulose according to the present invention and a bacterium producing it will be described below in detail. The bacterial cellulose according to the present invention refers to a cellulose produced by a bacterium.
For the purpose of the present invention, bacterial cellulose “being dispersed” in a liquid such as water refers to bacterial cellulose being floated or suspended in the liquid. The high dispersibility refers to, for example, the particle diameter or fiber width of a bacterial cellulose as a dispersoid being relatively small in a liquid, or the bacterial cellulose as a dispersoid being relatively uniformly floated or suspended in the liquid.
The bacterial cellulose according to the present invention has a high dispersibility in such an extent that it is almost uniformly dispersed in a liquid. Here, the liquid in which the bacterial cellulose is dispersed may be any of an organic solvent and an aqueous solvent; however, an aqueous solvent is preferable.
How high or low the dispersibility of a bacterial cellulose is can be measured, for example, using the light transmittance as an index; the relationship holds true that higher dispersibility results in a larger light transmittance and lower dispersibility results in a smaller light transmittance. The light transmittance can be determined by providing water containing the bacterial cellulose at a predetermined concentration to a spectrophotometer, irradiating the water with light at a predetermined wavelength, and measuring the amount of the transmitted light.
The bacterial cellulose according to the present invention has the physical characteristic of a transmittance of light at a wavelength of 500 nm of water containing the bacterial cellulose at a final concentration of 0.1±0.006% (w/w) of 35% or more. Here, examples of the transmittance of light at a wavelength of 500 nm of water containing the bacterial cellulose at a final concentration of 0.1±0.006% (w/w) according to the present invention can include 35% or more as well as 36% or more, 37% or more, 38% or more, 39% or more, 40% or more, 35% to 99% (both inclusive), 36% to 99% (both inclusive), 37% to 99% (both inclusive), 38% to 99% (both inclusive), 40% to 99% (both inclusive), 35% to 95% (both inclusive), 36% to 95% (both inclusive), 37% to 95% (both inclusive), 38% to 95% (both inclusive), 40% to 95% (both inclusive), 35% to 90% (both inclusive), 36% to 90% (both inclusive), 37% to 90% (both inclusive), 38% to 90% (both inclusive), 40% to 90% (both inclusive), 35% to 85% (both inclusive), 36% to 85% (both inclusive), 37% to 85% (both inclusive), 38% to 85% (both inclusive), 40% to 85% (both inclusive), 35% to 80% (both inclusive), 36% to 80% (both inclusive), 37% to 80% (both inclusive), 38% to 80% (both inclusive), and 40% to 80% (both inclusive).
The bacterial cellulose according to the present invention may also have a large average molecular weight compared to that of a plant-derived cellulose, such as a pulp-derived cellulose nanofiber. The average molecular weight of a cellulose can be measured using, for example, a chromatogram in the gel permeation chromatography as an index; the relationship holds true that a smaller molecular weight results in a larger retention volume of the peak top of such a chromatogram and a larger molecular weight results in a smaller retention volume. Specifically, the bacterial cellulose according to the present invention may have the physical characteristic of a retention volume of the peak top of the chromatogram in the gel permeation chromatography performed under the following conditions i) to vi) of from 2.5 mL inclusive to 3.0 mL exclusive: i) the column is a column 6.0 mm in inside diameter and 15 cm in length, packed with a methacrylate polymer having a particle diameter of 9 μm; ii) the guard column is 4.6 mm in inside diameter and 3.5 cm in length; iii) the column temperature is 35° C.; iv) the feed flow rate is 0.07 mL/minute; v) the eluent is a 40 to 42% (w/w) tetrabutylphosphonium hydroxide aqueous solution; and vi) the final concentration of the bacterial cellulose in the eluent is 0.2% (w/w).
The bacterial cellulose according to the present invention can be produced, for example, by causing a bacterium to produce a bacterial cellulose by culture in a culture medium containing a suitable carbon source.
Here, examples of the carbon source can include monosaccharides, such as glucose and fructose; disaccharides, such as sucrose, maltose, and lactose; oligosaccharides; sugar; sucrose-containing by-products generated in producing sugar, hydrolysates thereof, and isomerized sugar; saccharides, such as starch hydrolysates; mannitol; ethanol; acetic acid; citric acid; glycerol; and BDF-B. The carbon source can be properly set depending on the type of a bacterium, the culture conditions, the cost of production, and the like. BDF-B consists of 41.5% of glycerol, 21.4% of fatty acid, 12.4% of methanol, 6.3% of ignition residue, and 18.4% of others (Japan Food Research Laboratories) as a typical composition, and is a composition containing a large amount of glycerol available as a carbon source for a bacterium.
Here, sugar refers to a sweetener consisting essentially of sucrose (Kohjien, 6th Ed.), and, for the purpose of the present invention, may be a chemically synthesized one, or one produced using a natural product, such as sugar cane, sugar beet (white beet), sugar maple, gomuti ( Borassus flabellifer ), or sweet sorghum ( Sorghum bicolor dulciusculum ), as a raw material. Examples of the sugar according to the present invention can include non-centrifugal sugar, such as muscovado, shiroshita-to, casonade (brown sugar), wasanbon, or maple sugar, and centrifugal sugar, such as raw sugar or refined sugar. Examples of the refined sugar can include hard sugar, such as shirozara-to, coarse crystal medium soft sugar, or granulated sugar; soft sugar, such as white superior soft sugar or yellow soft sugar; processed sugar, such as cube sugar, crystal sugar, powdered sugar, or frost sugar; and liquid sugar.
The sucrose-containing by-product generated in producing sugar refers to one containing sucrose among by-products generated in a step of producing sugar, and specific examples thereof can include the pomace of natural raw materials, such as sugar cane and sugar beet as above described; molasses; and the residue generated in a purification step using filtration or ion-exchange resin.
The hydrolysate of a disaccharide, an oligosaccharide, sugar, or a sucrose-containing by-product generated in producing sugar refers to one obtained by subjecting the disaccharide, oligosaccharide, sugar, or sucrose-containing by-product generated in producing sugar to hydrolysis treatment, such as heating in an acidic solution.
The components in the culture medium other than the carbon source may be the same ones as those in well-known culture media used for the culture of bacteria, and preferably contain CMC. Specific examples of such a culture medium can include common nutrient culture media containing CMC, nitrogen sources, inorganic salts, and, as needed, organic trace nutrients, such as amino acids and vitamins. Examples of the nitrogen source can include organic or inorganic nitrogen sources, such as ammonium salts (e.g., ammonium sulfate, ammonium chloride, and ammonium phosphate), nitrates, urea, or peptone. Examples of the inorganic salt can also include phosphates, magnesium salts, calcium salts, iron salts, and manganese salts. Examples of the organic trace nutrient can include amino acids, vitamins, fatty acids, nucleic acids, and further peptone, casamino acids, yeast extracts, and soybean protein hydrolysates containing the nutrients. When an auxotrophic mutant requiring amino acids for growth is used, the required nutrients may further be supplemented.
The bacterium is not particularly limited provided that it can produce a bacterial cellulose; however, preferred is a bacterium capable of producing the bacterial cellulose under agitated culture or aerated culture, more preferably a bacterium assimilating BDF-B. Specific examples thereof can include bacteria of the genus Acetobacter , the genus Gluconacetobacter , the genus Pseudomonas , the genus Agrobacterium , the genus Rhizobium , and the genus Enterobacter . More specific examples thereof can include Gluconacetobacter intermedius, Gluconacetobacter hansenii, Gluconacetobacter swingsii, Acetobacter pasteurianus, Acetobacter aceti, Acetobacter xylinum, Acetobacter xylinum subsp. sucrofermentans, Acetobacter xylinum subsp. nonacetoxidans, Acetobacter ransens, Sarcina ventriculi, Bacterium xyloides , and Enterobacter sp.; however, among these, Gluconacetobacter intermedius is preferable. Still more specific examples thereof can include Gluconacetobacter intermedius strain SIID9587 (strain NEDO-01) (accession number NITE BP-01495), Gluconacetobacter xylinus strain ATCC53582 , Gluconacetobacter hansenii strain ATCC23769 , Gluconacetobacter xylinus strain ATCC700178 (BPR2001), Gluconacetobacter swingsii strain BPR3001E, Acetobacter xylinum strain JCM10150, and Enterobacter sp. strain CJF-002; among these, Gluconacetobacter intermedius strain SIID9587 (strain NEDO-01) (accession number NITE BP-01495) is preferable.
Culture methods can include, for example, agitated culture and aerated culture. Specific examples of the agitated culture can include culture using a fermenter, not involving aeration (non-aerated and agitated culture), culture using a fermenter, involving aeration (aerated and agitated culture), culture under swaying from side to side using a baffled flask (shake culture), and rotary culture using a baffled flask (rotation culture). The culture conditions may be well-known culture conditions used for the culture of the above bacteria; examples thereof can include culture conditions of an aeration volume of 1 to 10 L/minute, a rotation number of 100 to 800 rpm, a temperature of 20 to 40° C., and a culture period of 1 day to 7 days.
In the production of the bacterial cellulose according to the present invention, a step of pretreating a carbon source, a pre-preculture step, a preculture step, a step of purifying, drying, and suspending the bacterial cellulose, and the like may be carried out, as needed.
The bacterial cellulose according to the present invention can be used, for example, as an additive for paper strong agents, thickeners for food products, suspension stabilizers, and the like.
Then, the bacterium according to the present invention produces the above-described bacterial cellulose. For bacteria producing the bacterial cellulose according to the present invention, the same or equivalent components to those of the bacterial cellulose according to the present invention will not be described again.
The bacterial cellulose according to the present invention and a bacterium producing it will be described below based on Examples. However, the technical scope of the present invention is not intended to be limited to the features exhibited by these Examples.
EXAMPLES
Example 1
Isolation and Identification of Bacteria
(1) Isolation of Bacteria
Bacteria producing a bacterial cellulose by assimilating BDF-B were isolated. Specifically, using the protocol shown in FIG. 1 , enrichment culture was first carried out employing a culture medium containing 2% (w/v) of reagent glycerol (a guaranteed reagent from Wako Pure Chemical Industries Ltd.) in place of glucose in Hestrin-Schramm standard culture medium (composition; bacto pepton 0.5% (w/v), yeast extract 0.5% (w/v), Na 2 HPO 4 0.27% (w/v), citric acid 0.115% (w/v), glucose 2% (w/v); HS culture medium) (HS/glycerol culture medium) using apple and prune as separation sources. The resultant bacteria were inoculated on an HS/glycerol culture medium containing a cellulose staining reagent and cultured on plates at 30° C., and 15 bacterial strains producing bacterial celluloses were selected. Subsequently, these strains were inoculated on an LB culture medium (composition; trypsin 1% (w/v), yeast extract 0.5% (w/v), and sodium chloride 0.5% (w/v)) containing 2% (w/v) of reagent glycerol (a guaranteed reagent from Wako Pure Chemical Industries Ltd.) and subjected to stationary culture at 30° C. to form gelled films. The dry weight of the gelled films (hereinafter, referred to as “dry film weight”) was measured, and 8 strains for which the dry film weight was large were selected as bacteria assimilating glycerol and having a high bacterial cellulose-producing ability. Then, these strains were inoculated on an LB culture medium containing BDF-B and cultured on plates at 30° C., and further inoculated on the HS culture medium and subjected to stationary culture at 30° C. to form gelled films. The operation of selecting a bacterial strain for which the dry film weight was large among these bacteria, culturing on plates with the glycerol-containing LB culture medium or the HS/glycerol culture medium, and then subjecting the resultant to stationary culture on the HS culture medium was repeated to select one bacterial strain having a BDF-B-assimilating property and having a high bacterial cellulose-producing ability, which was called strain SIID9587.
(2) Identification of Bacteria
Sequencing was carried out according to an ordinary method for the strain SIID9587 of 1 (1) of this Example to determine the nucleotide sequence of the full-length 16S rDNA (1367 bp; SEQ ID NO: 1). Subsequently, 16S rDNA nucleotide sequence analysis and bacteriological property test were performed in TechnoSuruga Laboratory Co., Ltd.
[2-1] 16S rDNA Nucleotide Sequence Analysis
The 16S rDNA nucleotide sequence analysis was carried out using Aporon 2.0 (TechnoSuruga Laboratory Co., Ltd.) as software and Aporon DB-BA 6.0 (TechnoSuruga Laboratory Co., Ltd.) and the International Nucleotide Sequence Databases (GenBank/DDBJ/EMBL) as databases. As a result of homology search with Aporon DB-BA 6.0, the 16S rDNA nucleotide sequence for the strain SIID9587 (SEQ ID NO: 1) was found to have high homology to the 16S rDNA nucleotide sequence for the genus Gluconacetobacter and have the highest homology to the 16S rDNA nucleotide sequence for G. intermedius strain TF2 (accession number Y14694) (homology rate: 99.8%). As a result of homology search with GenBank/DDBJ/EMBL, the 16S rDNA nucleotide sequence for the strain SIID9587 (SEQ ID NO: 1) was also found to have high homology to the 16S rDNA nucleotide sequence for the genus Gluconacetobacter , and that for the type strain was found to have high homology to the 16S rDNA nucleotide sequence for G. intermedius strain TF2 (accession number NR_026435) (homology rate: 99.8%). The sequence of the accession number Y14694 is identical to the sequence of the accession number NR_026435. The results of the comparison between the 16S rDNA nucleotide sequences for the strain SIID9587 and G. intermedius strain TF2 (accession number Y14694 or NR_026435) are shown in FIGS. 2-1 and 2-2 . As shown in FIGS. 2-1 and 2-2 , 4 nucleotides were different between both sequences. In homology search with Aporon DB-BA 6.0, as a result of simplified molecular phylogenetic analysis based on the 16S rDNA nucleotide sequences for the top 15 strains having high homology, the strain SIID9587 was found to be included in the cluster formed by the species of the genus Gluconacetobacter.
[2-2] Bacteriological Property Test
The results of bacteriological property test are shown in FIG. 3 . As shown in FIG. 3 , the strain SIID9587 was different in property in terms of not growing on a 5% acetic acid-containing culture medium from known G. intermedius and not different in other properties therefrom (BRENNER et al., Bergey's manual of Systematic Bacteriology. Vol. 2. The Proteobacteria, Part C The Alpha-, Beta-, Delta-, and Epsilonproteobacteria. 2005. Springer. p72-77).
The above results of (2) [2-1] and [2-2] of this Example 1 showed that the strain SIID9587 belonged to Gluconacetobacter intermedius . On the other hand, it was shown that the strain SIID9587 was a new strain of G. intermedius since differences exist in the 16S rDNA nucleotide sequence and the bacteriological property between the strain SIID9587 and Gluconacetobacter intermedius strain TF2 as the type strain for G. intermedius as described above. Accordingly, this bacterial strain was deposited in the National Institute of Technology and Evaluation, Patent Microorganisms Depositary (NITE-IPOD; #122, 2-5-8 Kazusakamatari, Kisarazu-shi, Chiba 292-0818, Japan) under the accession number NITE BP-01495, Dec. 21, 2012. Hereinafter, the Gluconacetobacter intermedius strain SIID9587 (accession number NITE BP-01495) is called strain NEDO-01 ( G. intermedius strain SIID9587).
(3) Determination of Product
The strain NEDO-01 ( G. intermedius strain SIID9587) was precultured to proliferate bacterial cells. Subsequently, the culture solution obtained by the preculture (preculture solution) was added to the HS culture medium (carbon source; glucose), which was then subjected to stationary culture at 30° C. for about 8 days to perform the main culture to form a gelled film on the culture medium surface. The infrared spectroscopy (IR) spectrum and x-ray diffraction profile of the gelled film were obtained and analyzed according to an ordinary method. As a result, the gelled film was shown to be a cellulose having a I-type crystal structure. As a result of obtaining and analyzing a scanning electron microscope image according to an ordinary method, cellulose fibers having a width of the nano order (cellulose nanofibers) were shown to form a network structure in the gelled film. From these results, the strain NEDO-01 ( G. intermedius strain SIID9587) was determined to produce a cellulose.
Example 2
Evaluation of Product Obtained by Aerated and Agitated Culture
(1) Preparation of Product by Aerated and Agitated Culture
BDF-B was subjected to neutralization treatment and further subjected to autoclave treatment to provide pretreated BDF-B.
Culture media were prepared in which reagent glycerol (a guaranteed reagent from Wako Pure Chemical Industries Ltd.) was added in place of glucose as a carbon source in an HS culture medium containing 2% (w/v) CMC (chemical grade, from Wako Pure Chemical Industries Ltd.) and in which the pretreated BDF-B was added to a concentration of 2% (w/v) in place of glucose in the CMC-containing HS culture medium, and called a main-culture medium with glycerol and a main-culture medium with BDF-B, respectively. The strain NEDO-01 ( G. intermedius strain SIID9587) was first precultured to proliferate bacterial cells. Then, the preculture solution was inoculated on 5 L each of the main-culture medium with glycerol and the main culture medium with BDF-B and using the fermenter, subjected to aerated and agitated culture for 4 days under conditions of an aeration volume of 7 to 10 L/minute, a rotation number of 200 to 800 rpm, and a temperature of 30° C. to perform main culture. A 1% (w/v) NaOH aqueous solution was added to the culture solution obtained by the main culture (main-culture solution), which was then shaken at 60° C. and 80 rpm for 4 to 5 hours to lyse bacterial cells. After subjecting the resultant to centrifugation, the supernatant was removed to recover the precipitate to remove water-soluble bacterial cell components. The operation of adding ultrapure water thereto, performing centrifugation, and then removing the supernatant was repeated until the pH of the precipitate in a wet state reaches 7 or less to purify the product, and the resultant was called an agitated-culture BC solution.
(2) Preparation of Bacterial Cellulose by Stationary Culture
A gelled film was obtained by the method described in (3) of Example 1 and cut to a size of about 1 cm×1 cm. Subsequently, a 1% (w/v) NaOH aqueous solution was added thereto, which was then shaken at 60° C. and 80 strokes/minute for 4 to 5 hours and then shaken overnight at 20° C. The liquid was removed by filtration using a metal gauze to recover a gelled film. The operation of adding ultrapure water thereto and shaking the resultant overnight at 20° C. was repeated until pH reaches 7 or less for purification, followed by suspension treatment using a mixer for several minutes, and the resultant was called a mixer-treated stationary-culture BC solution.
(3) Analysis
The agitated-culture BC solution of (1) of this Example 2 and the mixer-treated stationary-culture BC solution of (2) of this Example 2 were each added dropwise onto a silicon plate, dried, and then provided to an infrared spectrophotometer (FT/IR-4200; JASCO Corporation), and measured at a cumulative number of 32 and a resolution of 2 cm −1 or 4 cm −1 to provide an IR spectrum. The results are shown in FIG. 4 . As shown in FIG. 4 , the IR spectra of the agitated-culture BC solutions obtained using the main-culture medium with BDF-B and the main-culture medium with glycerol had similar shapes to the IR spectrum of the mixer-treated stationary-culture BC solution. From these results, the product obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to agitated culture using BDF-B or reagent glycerol as a carbon source was determined to be a cellulose.
Example 3
Dispersibility of Bacterial Cellulose in Water
(1) Appearance of Water Containing Bacterial Cellulose
The agitated-culture BC solution using the main-culture solution with BDF-B of (1) of Example 2 and the mixer-treated stationary-culture BC solution of (2) of Example 2 were provided. Commercial pulp-derived cellulose nanofibers were added to water for dispersion, and the resultant was called a pulp-derived CNF solution. The agitated-culture BC solution, the mixer-treated stationary-culture BC solution, and the pulp-derived CNF solution were allowed to stand for 1 day, followed by observing their appearance. The results are shown in FIG. 5 .
As shown in FIG. 5 , the cellulose precipitation was observed in the pulp-derived CNF solution. Massive bacterial cellulose was observed in the mixer-treated stationary-culture BC solution, showing that the dispersion state of the bacterial cellulose was non-uniform. In contrast, in the agitated-culture BC solution, no precipitation or massive bacterial cellulose was observed and the bacterial cellulose was observed to be in the state of being uniformly dispersed. These results showed that the bacterial cellulose obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to agitated culture had high dispersibility and was uniformly dispersed in a liquid, such as water, compared to the bacterial cellulose obtained by subjecting the pulp-derived cellulose nanofibers or the strain NEDO-01 ( G. intermedius strain SIID9587) to stationary culture.
(2) Light Transmittance of Water Containing Bacterial Cellulose
[2-1] Comparison Between Bacterial Cellulose Obtained by Stationary Culture and Pulp-Derived Cellulose
In the method described in (1) of Example 2, rotation culture was performed under conditions of 150 rpm and a temperature of 30° C. for 3 days using a baffled flask in place of the fermenter as main culture to prepare agitated-culture BC solutions, which were called sample A (obtained using the main-culture medium with glycerol) and sample B (obtained using the main-culture medium with BDF-B). The agitated-culture BC solution obtained using the Main-culture medium with BDF-B of (1) of Example 2 was called sample C, and the agitated-culture BC solution obtained using the main-culture medium with glycerol was called sample D. The mixer-treated stationary-culture BC solution of (2) of Example 2 and the pulp-derived CNF solution of (1) of Example 3 were provided. These solutions were adjusted to a final cellulose concentration of 0.1±0.006% (w/w) and 1 mL each thereof were added to cells and subjected to a spectrophotometer (U-2001 double-beam spectrophotometer; Hitachi, Ltd.) to measure the transmittance of light at a wavelength of 500 nm. A polyethylene disposable cuvette (semi-micro, having a light path length of 10 mm and a light path width of 4 mm) was used as each cell, and ultrapure water was used as a reference. The results are shown in Table 1.
TABLE 1
Final Concentration
of Cellulose
Culture Method
Carbon Source
(% (w/w))
Transmittance (%)
Sample A
Agitated culture (Baffled Flask)
Reagent Glycerol
0.10505
74.75
Sample B
Agitated culture (Baffled Flask)
BDF-B
0.10309
70.53
Sample C
Agitated culture (Fermenter)
BDF-B
0.09570
63.82
Sample D
Agitated culture (Fermenter)
Reagent Glycerol
0.10375
49.66
Mixer-Treated Stationary-
Stationary culture
Glucose
0.09964
19.19
culture BC Solution
Pulp-Derived CNF Solution
0.10514
12.72
As shown in Table 1, the transmittance of the samples A, B, C, and D was 74.75%, 70.53%, 63.82%, and 49.66%, respectively, prominently high compared to 19.19% for the mixer-treated stationary-culture BC solution and 12.72% for the pulp-derived CNF solution, and roughly in the range of from 40% to 80% (both inclusive).
[2-2] Comparison Between Presence and Absence of CMC in Culture Medium
In the method described in (1) of Example 2, the HS culture medium containing 2% (w/v) CMC and the HS culture medium containing no CMC were each used to provide agitated-culture BC solutions. However, molasses was used in place of glucose as a carbon source. When molasses was used as a carbon source, the number of days in the main culture was set to 3 days in place of 4 days since the carbon source in the culture medium virtually disappeared at day 3 of the main culture. Subsequently, the light transmittance of bacterial cellulose-containing waters was measured by the method described in (2) [2-1] of Example 3. The results are shown in the following Table 2.
TABLE 2
CMC in
Carbon
Transmittance
Culture Medium
Culture Method
Source
(%)
Contain
Agitated culture
Molasses
57
Not Contain
Agitated culture
Molasses
18
As shown in Table 2, the transmittance when the HS culture medium containing CMC was used was 57%, whereas the transmittance when the HS culture medium containing no CMC was used was 18%.
The above results of (2) [2-1] and [2-2] of this Example 3 showed that the water containing the bacterial cellulose obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to agitated culture in the CMC-containing culture medium at a final concentration of 0.1±0.006% (w/w) had a transmittance of light at a wavelength of 500 nm of 40% to 80% (both inclusive). In other words, the agitated culture of the strain NEDO-01 ( G. intermedius strain SIID9587) in the CMC-containing culture medium was shown to provide a bacterial cellulose having a prominently high dispersibility in a liquid and uniformly dispersible in the liquid.
Example 4
Comparison in Transmittance and Bacterial Cellulose Production Rate Between Different Carbon Sources
Agitated-culture BC solutions were each obtained by the method described in (1) of Example 2. However, molasses and reagent glycerol were used as carbon sources in place of glucose. When molasses was used as a carbon source, the number of days in the main culture was set to 3 days in place of 4 days. Subsequently, the light transmittance of each bacterial cellulose-containing water was measured by the method described in (2) [2-1] of Example 3. The agitated-culture BC solution was dried to measure the absolute dry weight of the bacterial cellulose, and the concentration of the bacterial cellulose per 1 L of the culture medium was calculated based on the measurement results and defined as the amount of the bacterial cellulose produced (amount of BC produced; g/L). A value provided by dividing the amount of BC produced by the number of days in the main culture is calculated, and the value was defined as the bacterial cellulose production rate (BC production rate; g/L/day). The results are shown in FIG. 6 .
As shown in the table and left bar graph of FIG. 6 , the transmittance when molasses was used as a carbon source was 57% and was the same (57%) as that when reagent glycerol was used as a carbon source. These results showed that the culture of the strain NEDO-01 ( G. intermedius strain SIID9587) using molasses as a carbon source provided a bacterial cellulose having a high light transmittance at a wavelength of 500 nm of water containing the bacterial cellulose at a final concentration of 0.1±0.006% (w/w) and was the same as when reagent glycerol was used as a carbon source. In other words, the culture of the strain NEDO-01 ( G. intermedius strain SIID9587) using molasses as a carbon source was shown to provide a bacterial cellulose having high dispersibility and uniformly dispersible in a liquid.
As shown in the table and right bar graph of FIG. 6 , the BC production rate when molasses was used as a carbon source was 1.48 g/L/day and was about 1.5 times higher than that (0.95 g/L/day) when reagent glycerol was used as a carbon source. These results showed that the culture of the strain NEDO-01 ( G. intermedius strain SIID9587) using molasses as a carbon source provided a bacterial cellulose having high dispersibility in high amounts in a short period of time.
Example 5
Comparison in Transmittance and Bacterial Cellulose Production Rate Between Different Bacteria
An agitated-culture BC solution was obtained by the method described in (1) of Example 2. However, molasses was used as a carbon source in place of glucose. The strain NEDO-01 ( G. intermedius strain SIID9587) and Gluconacetobacter hansenii strain ATCC23769 , Gluconacetobacter xylinus strain ATCC53582 , Gluconacetobacter xylinus strain ATCC700178 (BPR2001), Gluconacetobacter xylinus strain JCM10150 , Gluconacetobacter intermedius strain DSM11804, and Gluconacetobacter xylinus strain KCCM40274 as known bacterial cellulose-producing bacteria were used as bacteria, respectively. When the strain NEDO-01 ( G. intermedius strain SIID9587) was used, the number of days in the main culture was set to 3 days in place of 4 days since the carbon source in the culture medium virtually disappeared at day 3 of the main culture. On the other hand, when the strain DSM11804 was used, the number of days in the main culture was set to 5 days in place of 4 days since the decrease in the carbon source in the culture medium was small in magnitude even at day 4 of the main culture. Subsequently, the light transmittance of each bacterial cellulose-containing water was measured by the method described in (2) [2-1] of Example 3. The amount of BC produced (g/L) and the BC production rate (g/L/day) were calculated by the method described in Example 4, and the transmittance and the BC production rate were quantified in bar graphs. The results are shown in FIG. 7 .
As shown in the table and left bar graph of FIG. 7 , the transmittance when the strain NEDO-01 ( G. intermedius strain SIID9587) was used was 57%, whereas the transmittance when G. hansenii strain ATCC23769 , G. xylinus strain ATCC53582 , G. xylinus strain ATCC700178 (BPR2001), G. xylinus strain JCM10150, G. intermedius strain DSM11804, and G. xylinus strain KCCM40274 were used was 20%, 33%, 29%, 27%, 9%, and 13%, respectively. These results showed that the transmittance of light at a wavelength of 500 nm of the water containing the bacterial cellulose obtained by culturing the strain NEDO-01 ( G. intermedius strain SIID9587) at a final concentration of 0.1±0.006% (w/w) was prominently high (35% or more) compared to the light transmittance of the water containing the bacterial cellulose obtained by culturing each of the strains other than NEDO-Ol ( G. intermedius strain SIID9587). In other words, the culture of the strain NEDO-01 ( G. intermedius strain SIID9587) was shown to be capable of providing a bacterial cellulose having high dispersibility and uniformly dispersible in a liquid.
As shown in the table and right bar graph of FIG. 6 , the BC production rate when the strain NEDO-01 ( G. intermedius strain SIID9587) was used was 1.48 g/L/day, whereas the BC production rate when G. hansenii strain ATCC23769 , G. xylinus strain ATCC53582 , G. xylinus strain ATCC700178 (BPR2001), G. xylinus strain JCM10150 , G. intermedius strain DSM11804, and G. xylinus strain KCCM40274 were used was 1.05 g/L/day, 1.03 g/L/day, 1.11 g/L/day, 1.10 g/L/day, 0.42 g/L/day, and 0.43 g/L/day, respectively. In other words, the BC production rate when the strain NEDO-01 ( G. intermedius strain SIID9587) was used was prominently high compared to the BC production rate when the strains other than NEDO-01 ( G. intermedius strain SIID9587) were used. These results showed that the culture of the strain NEDO-01 ( G. intermedius strain SIID9587) could provide a bacterial cellulose having high dispersibility in high amounts in a short period of time.
Example 6
Molecular Weight of Bacterial Cellulose
The samples A, B, C, and D and pulp-derived CNF solution of (2) of Example 3 were provided as samples. These samples were each freeze-dried, added to a 57 to 59% tetrabutylphosphonium hydroxide aqueous solution, and dissolved by standing at 35° C., followed by adding water to a tetrabutylphosphonium hydroxide concentration of 40 to 42% (w/w) and a sample concentration of 0.2% (w/w). Subsequently, centrifugation was carried out to precipitate impurities to recover the supernatant. The supernatant was subjected to the gel permeation chromatography under the following conditions to measure the retention volume of the peak top of the chromatogram. The supernatant was measured 3 times under the same conditions. The results are shown in Table 3, and a randomly selected chromatogram is shown in FIG. 8 .
Condition for Gel Permeation Chromatography
Instrument; high-performance liquid chromatograph (Shimadzu Corporation)
Column; a column 6.0 mm in inside diameter and 15 cm in length, packed with a methacrylate polymer having a particle diameter of 9 μm (TSKgel super AWM-H; Tosoh Corporation) Guard column; 4.6 mm in inside diameter and 3.5 cm in length (TSK guardcolum super AW-H; Tosoh Corporation)
Column temperature; 35° C.
Feed flow rate; 0.07 mL/minute
Sample injection volume; 10 μL
Eluent; a 40 to 42% (w/w) tetrabutylphosphonium hydroxide aqueous solution
Final concentration of bacterial cellulose in the eluent; 0.2% (w/w)
Control sample; pullulan having a molecular weight of 85.3×10 4 (Shodex standard P-82)
TABLE 3
Standard
Retention
Retention
Average/
Deviation/
Time/Minute
Volume/mL
mL
mL
Sample A (1st)
40.4
2.828
2.79
0.05
Sample A (2nd)
39.1
2.737
Sample A (3rd)
40
2.8
Sample B (1st)
39.8
2.786
2.81
0.03
Sample B (2nd)
39.9
2.793
sample B (3rd)
40.7
2.849
Sample C (1st)
40.1
2.807
2.82
0.02
Sample C (2nd)
40.5
2.835
Sample C (3rd)
40.1
2.807
Sample D (1st)
39.2
2.744
2.76
0.02
Sample D (2nd)
39.4
2.758
Sample D (3rd)
39.8
2.786
Pulp-derived
42.9
3.003
3.04
0.04
CNF Solution (1st)
Pulp-derived
43.4
3.038
CNF Solution (2nd)
Pulp-derived
43.9
3.073
CNF Solution (3rd)
Pullulan (1st)
45.7
3.199
3.24
0.04
Pullulan (2nd)
46.8
3.276
Pullulan (3rd)
46.4
3.248
As shown in Table 3 and FIG. 8 , the retention volume of the peak top of each of the samples A, B, C, and D was on average 2.79 mL, 2.81 mL, 2.82 mL, and 2.76 mL, respectively and small compared to 3.04 mL for the pulp-derived CNF solution and 3.24 mL for pullulan. These results showed that the average molecular weight of the bacterial cellulose obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to agitated culture was larger than that of the pulp-derived cellulose and more than 85.3×10 4 in terms of pullulan. Table 3 also showed that when the bacterial cellulose obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to agitated culture was subjected to the gel permeation chromatography under the above conditions, the retention volume of the peak top of the chromatogram reached 2.5 mL (inclusive) to 3.0 mL (exclusive) since the retention volume of the peak top of each of the samples A, B, C, and D was in the range of 2.737 to 2.849 mL.
Example 7
Morphology of Bacterial Cellulose
(1) Measurement of Fiber Width
The agitated-culture BC solution using the main-culture medium with glycerol of (1) of Example 2 and the mixer-treated stationary-culture BC solution of (2) of Example 2 were provided. These cellulose solutions were each adjusted to a concentration of about 0.001% (w/w), and then, 10 μL of each solution was added dropwise onto a Formvar-coated copper grid and air-dried. Subsequently, 5 μL of a 5% (w/v) gadolinium acetate aqueous solution was added dropwise thereto, and the excess solution was removed with a paper filter 10 seconds later for negative staining. The resultant was observed under a transmission electron microscope at an acceleration voltage of 80 kV and an observation magnification of 30,000 times to measure the width of cellulose fibers based on the observed image. The results are shown in FIG. 9 .
As shown in FIG. 9 , the width of the cellulose fibers was 17±8 nm for the agitated-culture BC solution, was prominently small compared to 55±22 nm for the mixer-treated stationary-culture BC solution, and had a small standard deviation. These results showed that the bacterial cellulose obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to agitated culture formed fine and uniform fibers showing small variations in width between the fibers.
(2) Determination of Uniformity of Fiber Width and Aggregation State
The agitated-culture BC solution using the main-culture medium with BDF-B of (1) of Example 2 and the pulp-derived CNF solution of (1) of Example 3 were provided. These cellulose solutions were each adjusted to a concentration of about 0.01% (w/w), and then, the operation of spraying the solution on a Formvar-coated copper grid and drying it using a dryer was repeated 10 times. Subsequently, 5 μL of a 5% (w/v) gadolinium acetate aqueous solution was added dropwise thereto, and the excess solution was removed with a paper filter. In addition, the sequence of dropwise adding 5 μL of ultrapure water and then removing the excess solution with a paper filter was repeated 2 times, followed by negative staining by air-drying. The resultant was observed under a transmission electron microscope at an acceleration voltage of 80 kV and an observation magnification of 10,000 times. The results are shown in FIG. 10 . It was also observed with crossed nicols using a polarizing microscope. The results are shown in FIG. 11 .
As shown in FIG. 10 , many cellulose fibers having comparable widths of the nano-scale were observed in the agitated-culture BC solution, whereas cellulose fibers having various widths, including widths as large as about 500 nm or more, were observed in the pulp-derived CNF solution. From these results, it was again determined that the bacterial cellulose obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to agitated culture formed fibers having a uniform width of the nano-scale.
As shown in FIG. 11 , relatively thick fibers as shown by arrows were definitely observed in the pulp-derived CNF solution, whereas dim images were observed in the portion enclosed by a dotted line in the agitated-culture BC solution. These results showed that relatively thick fibers, such as submicrofibers and microfibers, were present for the pulp-derived cellulose, whereas thin fibers of the nano-scale were uniformly dispersed for the bacterial cellulose obtained by subjecting the strain NEDO-01 ( G. intermedius strain SIID9587) to agitated culture.
Example 8
Evaluation of Bacterial Cellulose-Producing Ability
(1) Production Ability in Stationary Culture
Culture media were prepared in which pretreated BDF-B and reagent glycerol, respectively, were added in place of glucose as a carbon source in the LB culture medium, and called LB/BDF-B culture medium and LB/glycerol culture medium, respectively. The strain NEDO-01 ( G. intermedius strain SIID9587), Gluconacetobacter xylinus strain ATCC53582 , Gluconacetobacter hansenii strain ATCC23769, and Gluconacetobacter xylinus strain ATCC700178 (BPR2001) were each inoculated on each of the LB/glycerol culture medium and the LB/BDF-B culture medium and subjected to stationary culture at 30° C. for 7 days to form a gelled film. The operation of adding a 1% (w/v) NaOH aqueous solution thereto and performing autoclave treatment was repeated until the gelled film became white. Thereafter, the operation of adding water and performing autoclave treatment was repeated until pH reached 7 or less for purification. The bacterial cellulose obtained by drying after purification was measured for the absolute dry weight. The results are shown in FIG. 12 .
As shown in FIG. 12 , G. hansenii strain ATCC23769 produced small weights of bacterial celluloses in both of the LB/glycerol culture medium and the LB/BDF-B culture medium. G. xylinus strain ATCC53582 and G. xylinus strain ATCC700178 (BPR2001) produced relatively large weights of bacterial celluloses in the LB/glycerol culture medium, whereas no bacterial cellulose production was observed in LB/BDF-B culture medium. In contrast, the strain NEDO-01 ( G. intermedius strain SIID9587) produced comparably large weights of bacterial celluloses in both of the LB/glycerol culture medium and the LB/BDF-B culture medium. These results showed that the strain NEDO-01 ( G. intermedius strain SIID9587) could efficiently produce a bacterial cellulose by being subjected to stationary culture using either reagent glycerol or BDF-B as a carbon source. Its feature of being capable of producing a bacterial cellulose using BDF-B as a carbon source is a feature which other compared strains do not have, also advantageous on the practical side in which the by-product can be utilized, and greatly contributes to a reduction in production cost.
(2) Production Ability in Agitated Culture
The strains NEDO-01 ( G. intermedius strain SIID9587), strain ATCC53582, and strain ATCC23769 were each inoculated on 10 mL of the HS culture medium and subjected to stationary culture at 30° C. for 3 days for pre-preculture. Subsequently, the culture solution obtained by the pre-preculture was inoculated on 10 mL of the HS culture medium and subjected to stationary culture at 30° C. for 3 days for preculture. Then, 100 mL of each of the main-culture medium with glycerol and the main culture medium with BDF-B of (1) of Example 2 was placed in a bladed Erlenmeyer flask, and the preculture solution was inoculated in an amount corresponding to the same number of bacterial cells for each bacterial strain thereon and subjected to shake culture for 3 days under conditions of 150 rpm and 30° C. for the main culture. Subsequently, a bacterial cellulose in the main-culture solution was purified by the method described in (1) of Example 2. However, shake was performed at 60° C. and 80 rpm for 4 to 5 hours, followed by further shaking at 20° C. overnight. The purified bacterial cellulose was dried and measured for the absolute dry weight. The results are shown in FIG. 13 .
As shown in FIG. 13 , G. xylinus strain ATCC53582 was not observed to produce a bacterial cellulose in each of the main-culture medium with glycerol and the main culture medium with BDF-B. For G. hansenii strain ATCC23769, the absolute dry weight of the bacterial cellulose was relatively large when the main-culture medium with glycerol was used, but no bacterial cellulose production was observed when the main culture medium with BDF-B was used. In contrast, for the strain NEDO-01 ( G. intermedius strain SIID9587), the absolute dry weight of the bacterial cellulose was large when each of the main-culture medium with glycerol and the main culture medium with BDF-B was used. These results showed that the strain NEDO-01 ( G. intermedius strain SIID9587) could efficiently produce the bacterial cellulose by either stationary culture or agitated culture using either reagent glycerol or BDF-B as a carbon source.
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[Problem]
To provide a bacterial cellulose which is highly dispersible in a liquid, shows excellent molding properties and high miscibility with other materials when applied to materials, and, therefore, has a high applicability as a practical material, and a bacterium which produces the bacterial cellulose.
[Solution]
A bacterial cellulose, water that contains said bacterial cellulose at a final concentration of 0.1±0.006 (w/w) showing a light transmittance at a wavelength of 500 nm of 35% or greater, and a bacterium producing the bacterial cellulose. According to the present invention, the bacterial cellulose that is uniformly dispersible in a liquid such as water can be obtained. The bacterial cellulose shows excellent molding properties and high miscibility with other materials and, therefore, can contribute to the improvement in the qualities of a final product or production efficiency thereof or to the reduction of production cost.
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BACKGROUND OF THE INVENTION
This invention relates to a curved bar apparatus for smoothing and guiding moving webs such as paper or textiles.
Moving webs such as paper or textiles are processed at relatively high speeds by passing them over and between rollers to and from various processing steps to which the web is subjected such as drying, printing, etc. During movement over the rollers, these webs have a tendency to form wrinkles or folds which are undesirable since non-uniform treatment of the wrinkled web surface will result. Presently, the most commonly employed means for smoothing the surface of a moving web is by passing the moving web over a bowed roller, the surface of which rotates about its central axis and wherein the bow is in a direction such that the central portion of the web is elevated above the ends of the web. This roller configuration applies a tensile force in the lateral direction of the web thereby stretching it and unfolding or collapsing any wrinkles therein. While this means is generally effective for its intended purpose, it has disadvantages primarily resulting from the high cost thereof. For example, the bowed rollers are constructed with a central bowed bar which is enclosed by a plurality of bearings around which bearings extends a rubber cylinder which also is bowed and which rotates in contact with the moving web. The bearings employed are expensive to produce and to maintain and therefore are undesirable. Furthermore, there is a friction force between the roller and web which results in undesirable wear of the roller surface.
SUMMARY OF THE INVENTION
The present invention provides a curved bar adapted to oscillate linearly or angularly in a direction such that one component of the oscillating bar is in a direction normal to the web surface. The bar is supported so that it is located in contact with or adjacent to the moving web. The bar typically has a curvature of between about 0.5 and 5 percent as measured by the height of the center of the bar above the end of the bar divided by the linear distance between the bar ends. The bar is oscillated resonantly or nonresonantly so that the ratio of the frequency of the disturbing force to the frequency of free vibration of the system is as low as about 0.5 and as high as about 1.5. In one embodiment, the bar is formed from a hollow cylinder having a web-treating surface with openings such as slots or ports extending through its surface and is provided with a means for introducing a gas at superatmospheric pressure into the bar interior and through the ports. This invention is useful for smoothing the surfaces of relatively thin flexible moving webs such as paper or textiles.
The invention thus provides a nonrotating curved bar that is driven back and forth in a direction normal to the web surface passing thereover, and pressured air or other gas exits through the bar to create an air stream between the bar and the web. The reciprocating movement of the bar preferably is at a resonance of the moving system, i.e. of the dynamic system which is driven by the reciprocating movement of the bar.
DESCRIPTION OF THE FIGURES
This invention will be more fully described with reference to the accompanying figures.
FIG. 1 is an elevated view, in partial cross section, of a curved bar of this invention.
FIG. 2 is a cross-sectional view taken on line 2--2 of FIG. 1.
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 1.
FIG. 4 is an elevated cross-sectional view of an alternative embodiment of this invention.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 4.
FIG. 6 is an elevational view of the bar of this invention in use.
FIG. 7 is a side cross-sectional view of an apparatus of this invention with means for regulating gas flow.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 through 3, the illustrated oscillating bar 1 comprises a bowed hollow cylinder 2 having a plurality of ports or slots 3 therein connecting the interior of the cylinder to the outside atmosphere. The end 6 of the cylinder 2 is sealed and the end 4 of the cylinder 2 is connected to a conduit 5 which in turn is connected to a pump (not shown) adapted to supply gas under superatmospheric pressure into the cylinder 2. The cylinder 2 is supported by flange 7 and flange 8. Flange 8 rests upon flexible supports 9 made, for example, from rubber or other elastomeric material or structure and which extend along a sufficient portion of the length of the flange 8 to provide support for the flange 8 and cylinder 2. A plurality of electromagnets 10 are spaced apart along the length of and below the flange 8. Ferromagnetic masses 11 are attached to the bottom surface of the flange 8 and positioned above and adjacent to each electromagnet 10. Two flexible mountings 12 and 13 are attached to and extend along the length of the top surface of flange 8 and are located on either side of flange 7. The flexible mountings 12 and 13 are maintained under a slight compressive force by means of bars 14 and 15 which extend along the entire top surface of the flexible mountings 12 and 13. Bars 14 and 15 are fixed, at each end, to housing 16 so that they do not move during oscillation of cylinder 2. The housing 16 is fixed to supports 17 and 18 by any suitable means, preferably an adjustable means which permits adjusting the angle of contact of the cylinder 2 to a moving web which passes over the surface of cylinder 2.
In use, the amount and frequency of the power to the electromagnets are controlled so that the cylindrical bar 2, which functions somewhat like a nonrotating roller, will vibrate resonantly or nonresonantly and the electromagnets are operated from the same power source so that they operate in unison. The bar is caused to vibrate resonantly or nonresonantly so that the ratio of the frequency of the disturbing force to the frequency of free vibration of the system is as low as about 0.5 or as high as about 1.5. The electromagnets alternately attract and repel the ferromagnetic masses 11 with the amplitude of vibration being controlled by the amount of power supplied to the electromagnets 10. The frequency and amplitude of vibration are controlled so that the surface velocity of the cylinder or bar 2 causes the wrinkles or folds in the moving web to become collapsed. Increased surface velocity can be obtained by increasing either the frequency or the amplitude of vibration. Generally, the amplitude of oscillation of the cylinder 2 can be varied between 0.005 and 0.10 inch at frequencies varying about 60 or 360 cycles per second although successful operation may be achieved in certain situations with other parameters. Wrinkle collapse in the moving web can be obtained either by oscillating the cylinder 2 or by effecting the oscillation in conjunction with passing gas under pressure from the cylinder interior through the ports 3 and into the web. Increased gas pressures increase the effectiveness of the oscillating cylinder to collapse wrinkles in the web.
It is preferred, however, that the bar be oscillated (reciprocated) and that the air or other gas be ejected from the bar into the web-bar interface space concurrently. The two phenomena, i.e. bar movement and a gas stream, appear to cooperate in collapsing wrinkles and other deformities in the web and hence in smoothing it. Resonant movement of the bar, i.e. at a resonant frequency of the dynamic system which the electromagnets drive and which includes the mass of the curved bar and its mounting structure, is preferred because, relative to nonresonant operation, it requires far less input electrical power to the driving electromagnets and it develops fewer wearing forces in the mechanism.
Referring to FIGS. 4 and 5, the embodiment shown therein is constructed so that the spring element is located within the oscillating cylinder rather than outside it. As shown, the spring element comprises rubber mountings 20, 21 and 22. The mountings 21 and 22 are the same size and extend along the oscillating cylinder 23 at the same positions. The mountings 20, 21 and 22 are attached to fixed bar 24 which in turn is fixed to supports 25 and 26. Ferromagnetic masses 27 are attached to the bottom of fixed bar 24 along spaced-apart intervals and are located above and adjacent to the electromagnets 28. The mountings 21 and 22 are spaced apart from the electromagnets 28 and the ferromagnetic masses 27 so that electrical leads for the electromagnets 28 can be passed therebetween into the cylinder 23 which is caused to oscillate about fixed bar 24 in the same manner as the construction described above. The construction shown in FIGS. 4 and 5 also can be provided with ports communicating the cylinder interior with the outside atmosphere with one end of the cylinder being sealed and the other connected to a source of pressurized gas.
Referring to FIG. 6, a web 30 is passed sequentially over roller 31 under roller 32 over oscillating cylinder 2 and between rollers 33 and 34. The angle of contact between moving web 30 and oscillating cylinder 2 can be adjusted by loosening the bolt 35, positioning the oscillating roller 2 at the desired angle, and thereafter tightening the bolt 35. Any wrinkles that are formed in web 30 by contacting rollers 31 and 32 are removed during contact with oscillating roller 2 so that the wrinkles are not permanently pressed into the web 30 when passed between rollers 33 and 34.
An important aspect of the present invention will be discussed with reference to FIG. 7. The embodiment shown in FIG. 7 provides a means for maintaining a relatively stable gas cushion between the moving web 40 and the outer surface 41 of the reciprocating bar, i.e. oscillating cylinder 42. On each rod 43 and 44 are mounted a plurality of rollers 45 and 46. The rollers 45 and 46 are spaced apart along the length of each rod 43 and 44, which rods are bent to the contour of the cylinder 42. The ends of the rods 43 and 44 extend through end plates (not shown) of the cylinder 42 and are rotatable around an axis generally parallel to the main axis of the cylinder 42. Any means such as handles at one end of each rod 43 and 44 can be provided to rotate the rods. When the rods 43 and 44 are rotated, the rollers 45 and 46 also are rotated and, since they are in contact with semi-rigid plates 47 and 48, cause the plates 47 and 48 to move along the inside peripheral surface 49 of the cylinder 42. The plates 47 and 48 are shaped to conform to the general contour of the surface 49 and extend the length of cylinder 42. Thus the plates 47 and 48 can be positioned to selectively block some of ports 50 which extend through the cylinder 42 and to maintain the remaining ports 51 open to the atmosphere. When gas pressure is supplied to the interior of the cylinder 42, the plates 47 and 48 are pressed against the adjacent ports 50 to form a seal between the ports 50 and the interior of the cylinder 42. The number of ports selectively closed will depend upon the angle of contact between the web 40 and cylinder 42.
In operation, the embodiment shown in FIG. 7 provides a relatively stable air cushion between the moving web 40 and the surface 41. Gas is exited from the interior of the cylinder 42 through ports 51 but not through ports 50 by virtue of gas pressure provided within cylinder 42. The exited gas increases the gas pressure between the moving web 40 and surface 41 and when the web is relatively gas impermeable, the gas proceeds toward the open areas 52 and 53 between the web 40 and surface 41. As the gas proceeds toward openings 52 and 53, its pressure is reduced so that there is relatively slow exit of gas from the area between the web 40 and surface 41. In this manner, the desired gas cushion is maintained while requiring only relatively low gas pressures within cylinder 42 in the order of less than 20 psig. and in most cases about 5 psig. This embodiment provides substantial advantages in that lower gas pressures and less gas mass flow are required so that when the gas must be cleaned or dehumidified prior to contact with the web, less cleaning or dehumidification capacity is needed.
It is to be understood that the means for selectively closing the ports in the cylinder shown in FIG. 7 is merely illustrative and any conventional means can be used.
The web-treating surface of the oscillating bar in contact with the moving web should have a curvature of between about 0.5% (or even 0.1%) and 5% so that the moving web, during contact with the bar, is subjected to a tensile and/or shear force in a direction perpendicular to the direction of movement of the web. This force together with the force generated by the movement of the bar effectively collapse any wrinkles in the web. It has been found that the force generated by the gas exiting from the ports in the bar into the moving web is insufficient to smooth the web but that oscillation of the bar alone is sufficient to smooth the web. However, it has been found that by employing the moving gas in conjunction with the oscillating bar effects improved results as compared with using the oscillating bar alone.
While the present invention has been described above with reference to the use of electromagnets to obtain the desired oscillation, it is to be understood that any mechanical, pneumatic or electromechanical means can be employed to obtain oscillation. For example, the flange 7 or the housing 16 (FIGS. 1-3) could be attached to a driven cam mechanism or to a reciprocating pneumatic means to obtain the desired oscillation. Furthermore, any spring means other than rubber mountings can be employed such as metal springs. The rubber mountings can be intermittent or continuous throughout the length of the oscillating bar 2. In addition bars 14 and 15 can be intermittent or continuous throughout the length of the oscillating bar 2, and, when intermittent can be fixed by any suitable means such as being bolted to housing 16 which bolts can extend through the rubber mountings and through a clearance hole in flange 8. If desired, electromagnets 28 can be attached to the fixed bar 24 while the ferromagnetic masses are attached to the oscillating curved bar.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained. The curved and gas-cushioning reciprocating bar of the invention does not rotate and hence is free of bearing problems and other deficiencies of prior rotating apparatus. Moreover, the equipment of the invention provides successful web-smoothing operation and operates with efficient power consumption due to the resonant motion and optimized air cushion features. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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This invention provides an apparatus for removing wrinkles in a thin flexible moving web such as paper or textiles. The web is passed over a bar curved to effect a shear force on the web and/or a tensile force on the web in a direction perpendicular to the direction of movement of the web. The bar is oscillated resonantly or nonresonantly with one component of the oscillation being in a direction normal to the web surface so that its intermittent contact with the web causes any wrinkles therein to collapse. Gas, under super-atmospheric pressure can be passed through ports in the bar surface and into contact with the web to assist in collapsing wrinkles. SP
REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of Application Ser. No. 521,179, filed Nov. 6, 1974, now abandoned, which is a continuation-in-part of now-abandoned Ser. No. 436,838, filed Jan. 28, 1974, which in turn is a continuation-in-part of now-abandoned Ser. No. 331,199, filed Feb. 9, 1973.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the power flow analysis of a power grid embedded with a generalized power flow controller in the technical field, and more particularly to a method to incorporate the steady-state model of a generalized power flow controller into a conventional Newton-Raphson power flow algorithm, which can be applied to calculate the power flow solution of a power grid embedded with the generalized power flow controller.
[0003] 2. Description of Related Art
[0004] In the last decade, the power industry has extensively employed an innovative Flexible Alternative Current Transmission System (FACTS) technology to improve the utilization of existing transmission facilities. Connecting several Voltage Sourced Converters (VSCs) together forms various multiple functional FACTS controllers, such as: Static Synchronous Compensator (STATCOM), Unified Power Flow Controller (UPFC), and Generalized Unified Power Flow Controller.
[0005] The STATCOM, as shown in FIG. 1 , has one shunt VSC. The AC side of the shunt VSC connects to a bus of a power grid through a coupling transformer, and the DC side connects to a capacitor. The STATCOM provides reactive power compensation to regulate the voltage magnitude of the connected bus at a fix level.
[0006] The UPFC, as shown in FIG. 2 , has one shunt VSC and one series VSC. The AC side of the shunt VSC connects to a bus through a shunt coupling transformer, whereas the AC side of the series VSC is in series with a transmission line through a series coupling transformer. The DC sides of the shunt and series VSCs sharing the same capacitor. The shunt VSC can regulate the voltage magnitude of the connected bus at a fixed level, and the series VSC can control the active and reactive power of the connected transmission line.
[0000] The GUPFC, as shown in FIG. 3 , comprises one shunt VSC and a plurality of series VSCs. The connections and functions of the VSCs of GUPFC like those in the UPFC. These VSCs enable the GUPFC to control the voltage magnitude of the bus connected with the shunt VSC, and to control the active and reactive power of each transmission line which is in series with the series VSC.
[0007] The disclosed generalized power flow controller has a more flexible structure than the GUPFC. Comparing FIG. 3 and FIG. 4 , both the GUPFC and the generalized power flow controller has one shunt branch and a plurality of series branches. In GUPFC, the shunt branch and the receiving-end of each series branch connect to a common bus, bus s 1 , however, in the disclosed generalized power flow controller, the shunt branch and the receiving-end of each series branch are allowed to connect to different buses, bus s 1 , bus s 2 ˜s n , respectively.
[0008] The versatility of the generalized power flow controller can be applied to equalize both the active and reactive power in the transmission lines, relieve the overloaded transmission lines from the burden of reactive power flow, and restore for declines in resistive as well as reactive voltage drops.
[0009] Developing a steady-state model of the generalized power flow controller is fundamentally important for a power flow analysis of a power grid embedded with the generalized power flow controller. The power flow analysis provides the information of impacts on a power system after installing the generalized power flow controller. Many steady-state models of STATCOM, UPFC and GUPFC applied to power flow analysis have been set forth. In 2000, a STATCOM steady-state model accounting for the high-frequency effects and power electronic losses is proposed in an article “An improved StatCom model for power flow analysis”, by Zhiping Yang; Chen Shen; Crow, M. L.; Lingli Zhang; in IEEE Power Engineering Society Summer Meeting, 2000, Volume 2, Page(s):1121-1126.
[0010] A conventional approach to calculate the power flow solution of a power grid that includes a unified power flow controller is disclosed in an article “Unified power flow controller: a critical comparison of Newton-Raphson UPFC algorithms in power flow studies” by C. R. Fuerte-Esquivel and E. Acha in IEE Proc. Generation, Transmission & Distribution, 1997, and in an article “A comprehensive Newton-Raphson UPFC model for the quadratic power flow solution of practical power network” by C. R. Fuerte-Esquivel, E. Acha and H. Ambriz-Perez in IEEE Trans. Power System, 2000. In 2003, X.-P. Zhang developed a method to incorporate a voltage sourced based model of GUPFC into a Newton-Raphson power flow algorithm in an article “Modeling of the interline power flow controller and the generalized unified power flow controller in Newton power flow”, IEE Proceedings. Generation, Transmission & Distribution, Vol. 150, No. 3, May. 2003, pp. 268-274. The method included the voltage magnitude and phase angle of the equivalent voltage source into the state vector of Newton-Raphson iteration formula. The number of appended state variables is twice the number of VSCs. Thus, the length of state vector is varied depending on the number of VSCs. Therefore, the prior art can only be applied to the case with fixed number of VSCs. It can not be extended to the applications of STATCOM and UPFC. Besides, the speed of convergence is sensitive to the initial values of control variables of GUPFC. The initial values of control variables need a careful selection. Improper selection of the control variables may cause the solutions oscillating or even divergent.
[0011] Although the steady-state models of STATCOM, UPFC and GUPFC have been widely discussed individually, a method to incorporate steady-state models of STATCOM, UPFC, GUPFC and the generalized power flow controller into a Newton-Raphson power flow algorithm in a single framework have not been disclosed.
SUMMARY OF THE INVENTION
[0012] It is, therefore, an object of the present invention to provide a method to incorporate the steady-state model of a generalized power flow controller into a Newton-Raphson power flow algorithm with a robustness and rapid convergence characteristic, wherein the convergence speed is not sensitive to the selection of initial values of control variables of the generalized power flow controller.
[0013] It is another object of the present invention to provide a method to incorporate the steady-state model of the generalized power flow controller into a Newton-Raphson power flow algorithm, wherein the steady-state model has a flexible structure which can be applied to calculate the power flow solution of a power grid embedded with STATCOM, UPFC, GUPFC and the generalized power flow controller in a single framework.
[0014] To carry out previously mentioned objects, an innovative steady-state model of the generalized power flow controller is disclosed. The steady-state model has a flexible structure, wherein the sending-end of the each series VSC doesn't confine to connect to the same bus as the shunt converter connected. The feature of the steady-state model is expressing the variables of the steady-state model in a rectangular coordinate. Transforming the phasor from a conventional polar coordinate into d-q components reduces the appended state variables in the Newton-Raphson iteration. As a result, the increased iterations introducing by the generalized power flow controller is fewer than the prior art. The power flow calculation can preserve a rapid convergence characteristic.
[0015] In addition, a method to incorporate the steady-state model of the generalized power flow controller is disclosed. The method only incorporates the control variables of the shunt VSC into the state vector of Newton-Raphson power flow algorithm. The equivalent voltages of the series VSCs are calculated directly from the power flow control objectives and the bus voltages. Thus, the length of the state vector is the same regardless the number of series VSCs. As a result, the present invention can be utilized to calculate the power flow solution of a power grid embedded with STATCOM, UPFC, GUPFC and the generalized power flow controller.
[0016] The above and other objects and efficacy of the present invention will become more apparent after the description takes from the preferred embodiments with reference to the accompanying drawings is read.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is the interconnection of a STATCOM and a power grid according to the present invention;
[0018] FIG. 2 is the interconnection of a UPFC and a power grid according to the present invention;
[0019] FIG. 3 is the interconnection of a GUPFC and a power grid according to the present invention;
[0020] FIG. 4 is the interconnection of a generalized power flow controller and a power grid according to the present invention;
[0021] FIG. 5 is an equivalent circuit of a generalized power flow controller according to the present invention;
[0022] FIG. 6 is a flow chart for finding the power flow solution of a power grid embedded with the generalized power flow controller according to the present invention;
[0023] FIG. 7 shows the progress of control variables of the generalized power flow controller at each iteration according to the present invention.
[0024] FIG. 8 shows power mismatches of buses of the generalized power flow controller at each iteration according to the present invention; and
[0025] FIG. 9 shows a quadratic convergence pattern of the solution process according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] The generalized power flow controller 100 is a multi-functional FACTS controller. As depicted in FIG. 4 , the generalized power flow controller comprises a plurality of voltage sourced converters (VSCs) 111 , 121 , 131 and a plurality of coupling transformers 112 , 122 , 132 . These VSCs are connected back-to-back to share a common DC bus. The AC sides of VSCs couple to a power grid through coupling transformers, and the DC sides of VSCs link together to a DC coupling capacitor 110 .
[0027] One of these VSCs, VSC 1 111 , connects to an AC bus 113 in parallel, and the other VSCs 121 , 131 coupled to transmission lines 125 , 135 in series. These VSCs exchange active power via the common DC bus. The shunt VSC, VSC 1 111 , can provide the reactive power compensation to regulate the voltage magnitude at its connected bus s 1 113 , whereas each of the series VSCs, VSC 2 -VSC n 121 , 131 , can provide both the active and reactive power compensation to concurrently control the active and reactive power of the connected transmission line 125 , 135 .
[0028] The main function of VSC 1 is to keep a fixed DC voltage at DC bus by balancing the active power transfer among VSCs. The remaining capacity of VSC 1 is utilized to regulate the voltage magnitude at bus s 1 . In other words, the active power generated/absorbed by VSC 1 is restricted by the operation of other VSCs. Thus, the VSC 1 111 has only one control degree of freedom. It can provide the reactive power compensation to regulate the voltage magnitude of bus s 1 . On the other hand, each of series VSCs, VSC 2 -VSC n 121 , 131 , has two control degrees of freedom. It can simultaneously provide the active and reactive power compensation to control the active and reactive power in transmission line.
[0029] The equivalent circuit of the generalized power flow controller according to the present invention is derived next. As shown in FIG. 5 . The equivalent circuit includes one shunt branch and a plurality of series branches. Each branch comprises an equivalent voltage source in series with an impedance, wherein the equivalent voltage source models the VSC, and the impedance models the coupling transformer. The operation of these equivalent voltage source is dependent on each other. An active power balance equation, which will be derived later, must be satisfied to conform the energy conservation law.
[0030] The distinct feature of the present invention is expressing the control variables of the equivalent circuit in a rectangular coordinate. These variables are decomposed into d-q components by an orthogonal projection technique. For each generalized power flow controller, the voltage of the bus connecting the shunt branch is chosen as a reference phasor. The d component is in phase with the reference phasor, whereas the q component leads the reference phasor by 90 degree. For examples, the d-q decomposition on a voltage phasor, V xk =|V xk |∠θ xk , is expressed as:
[0000] V xk D =|V rk | cos(θ rk −θ s1 ); V xk Q =|V rk | sin(θ rk −θ s1 ) eq. (1)
[0000] where θ s1 , is the phase angle of the voltage at bus s 1 . The superscripts “D” and “Q” symbolize the d-q components of the corresponding variables, subscript “k” is the index of the VSC. The subscript “x” can be replaced with “s”, “r”, “sh” or “ser” to represent variables related to the sending-end, receiving-end, shunt branch and series branch, respectively. The d-q decomposition of a current phasor can be performed in a similar way.
[0031] The steady-state model of the generalized power flow controller can be incorporated into a Newton-Raphson power flow algorithm by replacing the generalized power flow controller with equivalent loads at the ends connected with the power grid. By the definition of the complex power, the equivalent load of the shunt branch is:
[0000]
[
P
s
1
Q
s
1
]
=
[
V
s
1
0
0
-
V
s
1
]
[
I
sh
D
I
sh
Q
]
,
.
eq
.
(
2
)
[0000] where I sh D and I sh Q are the d-q current components of the shunt branch. The equivalent load at the receiving-end of each series branch is set to achieve a power flow control objective as,
[0000]
[
P
rk
Q
rk
]
=
-
[
P
linek
ref
Q
linek
ref
]
,
k
=
2
,
Λ
,
n
,
eq
.
(
3
)
[0000] where n is the total number of VSCs, P linek ref and Q linek ref are the reference commands of the active and reactive power from the receiving-end of the kth series branch toward the connected transmission line. The equivalent load at the sending-end of the kth series branch is,
[0000]
[
P
sk
Q
sk
]
=
-
[
V
sk
D
V
sk
Q
V
sk
Q
-
V
sk
D
]
[
I
serk
D
I
serk
Q
]
,
k
=
2
,
Λ
,
n
,
eq
.
(
4
)
[0000] where I serk D and I serk Q are the d-q current components of the kth series branch, which can be obtained explicitly as:
[0000]
[
I
serk
D
I
serk
Q
]
=
-
1
V
rk
2
[
V
rk
D
V
rk
Q
V
rk
Q
-
V
rk
D
]
[
P
rk
Q
rk
]
.
[0000] Balancing the active power transfer among VSCs is a main function of VSC 1 . The remaining capacity of VSC 1 can provide the reactive power compensation to regulate the voltage magnitude of the connected bus at a fixed level. Therefore, the voltage magnitude at the bus connecting the shunt branch can be set to achieve a voltage magnitude control objective,
[0000] | V s1 |=V s1 ref , eq. (5)
[0000] where V s1 ref is the desired voltage magnitude at the bus s 1 .
Under the lossless assumption of the VSCs, the sum of the active power generated by the VSCs must equal to zero. Therefore, the active power generated by the VSCs must be constrained by an active power balance equation,
[0000]
P
dc
=
P
sh
+
∑
k
=
2
n
P
serk
=
0
,
eq
.
(
6
)
[0000] where P sh is the active power generated from the equivalent voltage source of the shunt branch, and P serk is the active power generated from the equivalent voltage source of the kth series branch,
After simple algebra manipulations, P sh and P serk , can be expressed as:
[0000] P sh =I sh D V s1 D +( I sh D 2 +I sh Q 2 ) R sh
[0000] P serk =I serk D ( V rk D −V sk D )+ I serk Q ( V rk Q −V sk Q )+( I serk D 2 +I serk Q 2 ) R serk
[0000] Each of STATCOM, UPFC, GUPFC and the generalized power flow controller has different numbers of series VSCs. However, they are in common by having one shunt VSC. Consequently, UPFC, STATCOM and GUPFC can be regarded as a subdevice of the generalized power flow controller. For example, if the shunt branch and series branches share the same sending-end bus, ie. bus s 1 , s 2 and s n connect together, the foregoing derivations can be applied to the GUPFC. Similarly, UPFC has only one series branch, set n=2 in Eq (6) in a UPFC application. Furthermore, because the STATCOM has no series branch, the summation part of Eq (6) is omitted, ie. Eq. (6) becomes P dc =P sh , in a STATCOM application.
[0032] In the present invention, regardless of the number of series VSCs, and whether the shunt branch and the series branch share the same sending-end or not, the power flow solution can be found under the same procedures. That is, the present invention can be utilized to calculate the power flow solution of a power grid embedded with STATCOM, UPFC, GUPFC and the generalized power flow controller.
[0033] The power flow solution can be obtained by solving power flow equations, which is a set of nonlinear equations describing the power balance at each bus of a power grid. The Newton-Raphson power flow algorithm is an iterative procedure to solve power flow equations. The iterative formula of the algorithm is expressed as,
[0000] x i+1 =x (i) −[J ( x (i) )] −1 f ( x (i) ), eq. (7)
[0000] where x is a state vector, f(x) is a mismatch vector, and i means the ith iteration. The elements of the state vector are called state variables which include the voltage magnitudes and the phase angles of buses of a power grid. The elements of the mismatch vector include the net active and reactive power flowing into each bus, and the other constraints of the power system. J is a corresponding Jacobian matrix which is formed by the first-order partial derivatives of the mismatch vector. After considering the equivalent loads of the generalized power flow controller, the mismatch vector is modified as:
[0000] f′=f+Δf GUPFC , eq. (8)
[0000] where Δf GUPFC =[Δf bus |Δf control ] T =[P s1 Q s1 P sk Q sk P rk Q rk | P dc ] T ,
The first part of Δf GUPFC , Δf bus , relates to the equivalent loads at the ends of the generalized power flow controller. The elements of Δf bus are added to the corresponding position of f. The second part of Δf GUPFC , Δf control , is the added constraints introduced by the generalized power flow controller. The element of Δf control augments the size of the mismatch vector. Therefore, the length of f′ is longer than that of f by 1. The elements of Δf GUPFC have been derived in eq. (2), (3), (4) and (6).
[0034] With regard to the state vector of the iteration formula, Instead of selecting the voltage magnitudes and phase angles as state variables, the d-q current components of the shunt branch have been chosen as state variables. Hence, elements of the state vector associated with the generalized power flow controller are expressed as:
[0000] x GUPFC =[x bus |x control ] T =[θ s1 θ sk |V sk |θ rk |V rk ||I sh D I sh Q ] T , eq. (9)
[0000] where x bus consists of the original state variables relevant to the generalized power flow controller, and x control consists of the added state variables introduced by the generalized power flow controller. Because |V s1 | is regulated by I sh Q at a fixed voltage level, |V s1 | has been omitted from x bus . The elements of x control augments the size of the original state vector. Thus, one element is omitted and two new elements are appended to the state vector. The length of the state vector is increased by one after embedding the generalized power flow controller. The Jacobian matrix is also modified according to the first-order partial derivatives of f′ as:
[0000]
J
′
=
J
+
Δ
J
GUPFC
,
Eq
.
(
10
)
where
Δ
J
GUPFC
=
[
0
0
0
0
0
∣
∂
P
s
1
∂
I
sh
D
∂
P
s
1
∂
I
sh
Q
0
0
0
0
0
∣
∂
Q
s
1
∂
I
sh
D
∂
Q
s
1
∂
I
sh
Q
∂
P
sk
∂
θ
s
1
∂
P
sk
∂
θ
sk
∂
P
sk
∂
V
sk
∂
P
sk
∂
θ
rk
∂
P
sk
∂
V
rk
∣
0
0
∂
Q
sk
∂
θ
s
1
∂
Q
sk
∂
θ
sk
∂
Q
sk
∂
V
sk
∂
Q
sk
∂
θ
rk
∂
Q
sk
∂
V
rk
∣
0
0
0
0
0
0
0
∣
0
0
0
0
0
0
0
∣
0
0
-
-
-
-
-
⊣
-
-
∂
P
d
c
∂
θ
s
1
∂
P
d
c
∂
θ
sk
∂
P
d
c
∂
V
sk
∂
P
d
c
∂
θ
rk
∂
P
d
c
∂
V
rk
∣
∂
P
d
c
∂
I
sh
D
∂
P
d
c
∂
I
sh
Q
]
[0035] The upper left part of ΔJ GUPFC adds to the corresponding position of the original Jacobian matrix J. The other parts of ΔJ GUPFC augment the size of J. Since P r2 □Q r2 □P rk and Q rk are constants, the elements of ΔJ GUPFC in the fifth and sixth rows are all zeros. Because the length of the mismatch vector and the state vector are both increased by one, the size of J′ is bigger than J by one row and one column.
[0036] After modifying the mismatch vector and Jacobian matrix, the iterative formula for updating the state vector becomes
[0000] x (i+1) =x (i) −[J′ ( x (i) )] −1 f′ ( x (i) ) eq. (11)
[0037] When the state vector converges within a specified tolerance, the equivalent voltage of shunt VSC can be recovered from I sh D and I sh Q . Simple manipulations yield the d-q components of the equivalent voltage of the shunt VSC,
[0000]
[
V
sh
D
V
sh
Q
]
=
[
R
sh
-
X
sh
X
sh
R
sh
]
[
I
sh
D
I
sh
Q
]
+
[
V
s
1
0
]
.
Eq
.
(
12
)
[0000] The equivalent voltages of the series VSCs can be calculated explicitly by:
[0000]
[
V
serk
D
V
serk
Q
]
=
[
R
serk
-
X
serk
X
serk
R
serk
]
[
I
serk
D
I
serk
Q
]
+
[
V
rk
D
-
V
sk
D
V
rk
Q
-
V
sk
Q
]
,
k
=
2
,
Λ
,
n
.
Eq
.
(
13
)
[0000] Finally, the polar form of the equivalent voltage of the shunt VSC and the series VSC can be obtained by:
[0000]
V
sh
∠
θ
sh
=
V
sh
D
2
+
V
sh
Q
2
∠
(
tan
-
1
V
sh
Q
V
sh
D
+
θ
s
1
)
Eq
.
(
14
)
V
serk
∠
θ
serk
=
V
serk
D
2
+
V
serk
Q
2
∠
(
tan
-
1
V
serk
Q
V
serk
D
+
θ
s
1
)
Eq
.
(
15
)
[0038] Under the assumption of known generations and loads, the basic power flow solutions, including voltages of all buses in the power grid and the equivalent voltages of the shunt and series VSCs of the generalized power flow controller, can be find by using the disclosed method, and the detail power flow solutions, including the active and reactive power flows into each transmission line, reactive power output of each generator, can be determined by using the basic power flow solution together with the fundamental circuit theory. A summary of procedures to calculate the power flow solution of a power grid embedded with the generalized power flow controller is depicted in FIG. 6 .
Step 301 : set the initial value of the state vector, wherein the elements of the state vector, called state variables, comprising the voltage magnitudes of all buses excluding the bus connected to the shunt branch of the generalized power flow controller, the phase angles of all buses, the d-q components of the shunt branch current of the generalized power flow controller; the voltage magnitude of each bus initially sets to 1.0 p.u., the phase angle of each bus, the d and q components of the shunt branch current of the generalized power flow controller all initially set to 0. Step 302 : construct the mismatch vector, f of a power grid ignoring the generalized power flow controller. Step 303 : establish the corresponding Jacobian matrix J using the first order derivatives of the mismatch vector f obtained in step 302 . Step 304 : perform a d-q decomposition on the voltage of the receiving-end of each series branch by eq. (1). The d-q decomposition uses the voltage of the bus connected to shunt branch of the generalized power flow control as a reference phasor. The d component, V rk D , is in phase with the reference phasor, whereas the q component, V rk Q , leads the reference phasor by 90 degree. Step 305 : use eq. (2) to calculate the equivalent load of the shunt branch of the generalized power flow controller. Step 306 : judge whether there exists a series VSC, if it exists, go to step 307 , otherwise, go to step 308 . Step 307 : calculate the equivalent loads at the sending-end and receiving-end of each series branch by using eq. (3) and eq. (4), from the 2 nd to n th series branch, wherein n is the number of VSCs. Step 308 : use eq. (6) to calculate the total active power generated from VSCs, P dc . Step 309 : modify the mismatch vector by using eq. (8). Step 310 : modify the Jacobian matrix by using eq. (10). Step 311 : substitute the modified mismatch vector and modified Jacobian matrix into eq. (11) to update the state vector. Step 312 : judge whether the state vector converges within specified tolerance. If it does not, go back to step 302 . Otherwise, proceed to step 313 . Step 313 : calculate the equivalent voltages of the VSCs by using use eq. (14) and eq. (15). Step 314 : calculate the power flow solution, which includes the voltage of each bus, the active and reactive power flow of each transmission line, the reactive power generated from each generator.
[0053] Simulating several test systems embedded with STATCOM, UPFC, GUPFC and the generalized power flow controller has been performed to validate the present invention. The descriptions of the test systems are as follows:
Case 1: IEEE 300-bus test system without installing FACTS controller, referred to as a base case. This case provides a comparison basis with other cases. Case 2: Similar to Case 1, except that it has been installed with one additional GUPFC. The GUPFC has one shunt branch and three series branches. The shunt branch is in parallel with bus 37 to control its voltage magnitude. The series branches are in series with line 37 - 49 (the transmission line linking bus 37 and bus 49 ), line 37 - 89 and line 37 - 40 , respectively, to control their active and reactive power flow. Case 3: Similar to Case 2 except that it has been installed with one additional generalized power flow controller, it is referred to as GPFC. GPFC has one shunt branch and two series branches. The shunt branch is in parallel with bus 102 to control its voltage magnitude. The series branches are in series with line 102 - 104 and line 103 - 105 , respectively, to control their active and reactive power flow. Case 4: Similar to Case 3 except that it has been installed with one additional UPEC. The UPFC has one shunt branch and one series branch. The shunt branch is in parallel with bus 7 to control its voltage magnitude. The series branch is in series with line 7 - 131 to control its active and reactive power. Case 5: Similar to Case 4 except that it has been installed with one additional STATCOM. The STATCOM has one shunt branch, and it is in parallel with bus 81 to control its voltage magnitude.
[0059] In the above test cases, assuming the coupling transformers have the same impedances as 0.01+j0.05 p.u. The allowable tolerance of Newton-Raphson algorithm is set to 10 −12 . The initial values for the state variables are 1∠0° for the bus voltages, and 0 for I sh D and I sh Q . Table 1 shows the iteration numbers required for obtaining power flow solution in the different test systems. The simulation results showed that incorporating the steady-state model of the generalized power flow controller will not increase the iteration number for obtaining the power flow solution within the same allowable tolerance.
[0000]
TABLE 1
Iteration numbers required for obtaining power
flow solution in the different test systems
Case
1
2
3
4
5
Iteration
6
6
6
6
6
numbers
[0060] FIG. 7 shows the convergence pattern of state variables of the GUPFC. As shown, the current components I sh Q and I sh D converge to their target values after six iterations, respectively.
[0061] Case 3 is designed to demonstrate a distinguishing feature of the present invention. Even through the sending-ends of shunt branch and series branches of the GPFC connect to different buses, the power flow solution converges as rapid as the base case does. FIG. 8 shows the power mismatches at the sending-end and receiving-end buses of the GPFC. After six iterations, the power mismatches are within a tight tolerance, and thus a precise power flow solution is obtained. Therefore, it is well demonstrated that the power flow calculation achieves a rapid convergence characteristic using the steady state model of the generalized power flow controller according to the present invention.
[0062] FIG. 9 shows a quadratic convergence pattern of the solution process of Case 4, in which the dotted line is a typical quadratic convergence pattern and the solid line is the convergence curve of Case 4. It reveals that the quadratic convergence characteristic is preserved after embedding one STATCOM, one UPFC, one GUPFC and one generalized power controller into a power grid.
[0063] According to the simulation results, the power flow solution of the test cases, installed with STATCOM, UPFC, GUPFC the generalized power flow controller, can converge as rapidly as the base case does. It concludes that incorporating the steady-state model of the generalized power flow controller will not degrade the convergence speed of Newton-Raphson algorithm.
[0000] Many changes and modifications in the above described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.
|
A method to incorporate the steady-state model of the generalized power flow controller into a Newton-Raphson power flow algorithm is disclosed. The disclosed method adopts a flexible steady-state model of the generalized power flow controller, which can be applied to calculate the power flow solution of a power grid embedded with STATCOM, UPFC, GUPFC and the generalized power flow controller in a single framework. The disclosed method only incorporates the control variables of the shunt voltage sourced converter into the state vector of Newton-Raphson power flow algorithm. The increment of state variables due to incorporating the generalized power flow controller is less than the prior art. Further, the method can preserve the quadratic convergence characteristic of the Newton-Raphson power flow algorithm after embedding the generalized power flow controller into a power grid.
| 6
|
BACKGROUND OF THE INVENTION
The present invention relates to a network priority determining system which, in a network in which various computers, terminals, etc., transmit data to one another, and in which a priority for transmitting terminals is established in such a manner as to efficiently operate the network with a minimized standby time.
A network system in which various computers, terminals, etc., transmit data to one another via a common line or lines requires a system for giving access (transmission rights) to nodes sequentially.
An example of such an access system is a system in which a certain frame (hereinafter referred to as "a free token" when applicable) is circulated through nodes sequentially wherein a node wishing to make a transmission request "catches" the token and changes it into a busy token, which is transmitted with a data packet. As described in IEEE Draft Standard 802.5, "Token Ring Access Method and Physical Layer Specifications", Sept. 23, 1983, a method has been proposed in which the order of priority is given to transmission packets in such a manner that a packet higher in priority is transmitted earlier. This method is carried out as follows:
(1) The token has a priority field P and a reservation field R, and each node writes these levels in respective registers P r and R r whenever it receives the token. (The levels contained in the respective fields and registers are designated by the same reference characters for convenience).
(2) If the priority of the free token is P, and the priority level P m of the transmission request packet of the node is higher than or equal to that of the free token, the free token is changed to a busy token for transmission of the data.
(3) After the packet is transmitted, the node outputs a free token. In this case, the levels of P and R are determined as follows:
(i) for P r >max (R r , P m )
P=P r , R=max (R r , P m ),
(ii) for P r <max (R r , P m )
P=max (R r , P m ), R=0,
where P r is the level held in the priority field register (indicating the present priority level), R r is the level of the reservation field register, P m is the priority level of the transmission request packet, P is the set level of the priority field of the transmitting token, R is the set level of the reservation field of the transmitting token, and "0" represents the lowest level of priority.
(4) The node which has increased the level of the priority field in the token stores the original level in a stack S r and the resultant level in a stack S x . The number of stacks S r provided is equal to the available number of priority levels, as is the number of stacks S x . This node is referred to as a stacking station.
(5) When the stacking station node confirms that none of the nodes have a packet whose level of priority is higher than that of the network outputted by the node, the level of priority is lowered as follows:
(i) In the case of S r >R r ,
the stack S x is moved up, a token with P=S r and R=R r is transmitted, and the stack S r is moved up. When the stack S r has been depleted, the stacking station is released.
(ii) In the case of R r >S r ,
the stack S x is moved up, a free token with P=R r and R=0 is transmitted, and the level of P is placed in the stack S x . (The stacking station is not changed.)
(6) The reservation field is revised when the following conditions are satisfied:
(i) the priority of the transmission request packet is lower than that of the network, and
(ii) the level R r of the reservation of the reservation field is lower than the level of the priority of the transmission request packet.
(7) In order to transmit the free token after the transmission of the data packet, the following operations are carried out:
(i) In the case of P r >R r and P r >P m , in order to output a free token with P=P r and R=max (R r , P m ), comparators (1), (2) and (3) are used to determine the relative levels of P and R.
(ii) In the case of P r <max (R r , P m ), in order to output the free token of P=max (R r , P m ) and R=0, the comparators (1), (2) and (3) are used for decision, to determine the levels of P and R. In this operation, the level of P r is placed in the stack S r , and the level of P is placed in the stack S x .
FIG. 1 is a block diagram showing a priority determining system as described in IEEE Draft Standard 802.5, which is an example of the conventional priority determining system.
In FIG. 1, three registers 1 hold the latest token's priority level and reservation field level and a transmission request packet's priority level. Six comparators 5 are provided for comparison of the contents of the three registers 1 with the contents of stacks 3 and 4.
A priority level control circuit 6 performs the following operations according to the outputs of the comparators 5 and a token output timing signal:
(i) The circuit 6 determines the levels of S r and S x .
(ii) The circuit 6 outputs a selection signal for determining the priority level P and the level R in the reservation field of the token to be transmitted. A data selector 2 operates to select the levels of P and R with the aid of the selection signal from the priority level control circuit 6. The height of the stacks S r and S x coincides with the available number of priority levels.
The operation in the case where the stacking station lowers the priority of the network will now be described.
If, in the case where the stacking station has no transmission data packet or the comparator 6 has found P m =S x , the comparator 5 determines that the priority level P r of a received free token is equal to S x then:
(i) when the comparator 4 determines S r >R r , the stack S x is moved up, a free token with P=S r and R=P r is transmitted, and the stack S r is moved up,
(ii) if S r <R r , a free token with P=R r and R=0 is transmitted, and the level of P is placed in the stack S x .
The level of the reservation field is renewed by establishing R=P m in the case where the comparator 2 has determined R r ≧P m and the comparator 3 has determined P m ≧R r .
As described above, the levels of P and R are selectively determined by the data selector 2 with the aid of the output of the priority control circuit.
The above-described prior art method suffers from the following problems:
(i) Level of priority of the free token:
If, when the node outputs a free token whose priority is increased, and the present priority P r of the network is higher than the levels of R r and P m , a free token of priority P r is outputted. If R r is lower than P r , the probability is small that a data packet whose priority is higher than P r is present in other nodes. Therefore, the probability is high that the token will return to the node which has outputted the token, and hence an operation of lowering the priority is carried out.
If a priority of P=max (R r , P m ) is employed in outputting the free token, the period of time for which the token circulates through the nodes without being caught is decreased, and therefore the efficiency of the network is increased.
(ii) Standby time when the level of priority is changed.
It is assumed that the priority level is changed in the order of "1", "2", "3", and "5". These changes mean that the priority of each of the stacking stations is increased by one step in sequence. Therefore, when it is required to lower the priority level "5" of the token to the priority "1", the priority level "5" must be lowered through the priority levels "3" and "2" to reach the priority level "1"; that is, it is impossible to decrease the priority level "5" directly to "1". Therefore, if only a packet having a priority level of "1" exists in the network, then the standby time which elapses until a free token is caught which allows transmission of the packet is about three times as long as in a case where the priority level is changed form "5" directly to "1".
Moreover, the method of determining the priority level according to data from the reservation field in the above-described system suffers from the following problems when the size of a data packet is large compared with the transmission speed of the network, that is, in the case where a long period of time is required for the transmission of the data packet and therefore a new transmission request packet occurs during the period of time:
(1) In the case where, in outputting a free token, the priority level has been determined according to the reservations made by the nodes, a significant period of time has passed after the reservations were made. Therefore, transmission request packets whose priority level are higher than the aforementioned priority level may occur in the nodes. In this case, a packet having higher priority should be dealt with earlier, but it is not.
(2) In the case of data such as audio data which should be especially high in real-time response, the delay characteristic fluctuates, causing distortion in the reproduced sound.
Still further, the above-described prior art system suffers from the following problems:
(i) Level of priority of the free token:
If, when the node outputs a free token whose priority level is increased, the present priority level P r of the network is higher than the levels of R r and R m , a free token whose priority level is P r is outputted. If R r is lower than P r , the probability is small that a data packet whose priority level is higher than P r is present in other nodes. Therefore, the probability is high that the token will return to the node which has outputted the token, whereupon the operation of lowering the priority is carried out.
If a priority level of P=max (R r , P m ) is employed in outputting the free token, the period of time for which the token circulates through the nodes without being caught is decreased, and therefore the efficiency of the network is increased. Therefore, the probability is large that the token will return to its home node (the node which outputted the token) and its priority thus lowered.
If, in outputting a free token, the priority level is set to P=max (R r , P m ), the period of time in which the token is circulated without being caught is decreased, with the result that the efficiency of the network is improved.
(ii) Change of the free token:
If the level of priority is changed in the order of "1", "2", "3", and "5", then it is necessary to lower it in the order of "5", "3", "2", and "1". That is, the priority is not lowered from "5" directly to "1". Therefore, if only packets of priority "0" are present in the network, the waiting time which elapses before the transmission-enabling free token is caught is about three times as long as that in the case where the priority is lowered from "5" directly to "1".
(iii) Each of the nodes (equal in number to the number of available priority levels) requires two stacks, and therefore the hardware is necessarily intricate. The number of stacks used at all times is no more than (the number of available priority levels)×2 in the overall network. This means that hardware circuits which are scarcely used must nevertheless be provided.
SUMMARY OF THE INVENTION
As object of the invention is therefore to solve the above-described problems accompanying a conventional access system.
In accordance with this and other objects, an access method is provided by the invention wherein a priority level is determined from the levels of R r and P m . Therefore, the priority level can be changed immediately. Accordingly, it is unnecessary for the stacking station to perform this function. Thus, the time required for changing the priority level and for standby processing in outputting the free token is greatly reduced.
In accordance with another aspect of the invention, there is provided a priority level determining system in which a priority control field P c is provided in a token and utilized for both a free token and a busy token in the network, whereby the number of priority level bits in a frame is halved and the priority can be changed in an extremely short time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a conventional network priority level determining system;
FIG. 2 is a diagram showing an example of a token frame used in the conventional system of FIG. 1;
FIG. 3 is a block diagram of a network priority determining system according to a first embodiment of the invention;
FIGS. 4A and 4B are block diagrams showing network priority level systems according to a second embodiment of the invention;
FIG. 5 is a block diagram showing a network priority determining system in accordance with a third embodiment of the invention; and
FIG. 6 shows the arrangement of a token frame employed in the system of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The inventive access method will now be described in detail.
(1) A token is assumed to have a priority field P and a reservation field R, and each node writes its level in P r and R r whenever it receives the token.
(2) If the priority level of a free token is P, and the priority level P m of a transmission request packet of a node is higher than that of the free token, the free token is changed into a busy token to allow transmission of the data.
(3) After the packet is transmitted, the node outputs a free token. In this case, the levels of P and R are determined as follows:
(i) when the transmitting packet remains in the cue,
P=max (R r , P m )
R=0,
(ii) when no transmitting packet remains in the cue,
P=R r
R=0.
(4) No stack is provided. (Changes in the priority levels are not stored.)
(5) The reservation field is revised when the following conditions are satisfied:
(i) the priority level of the transmission request packet is lower than that of the network; and
(ii) the level R r of the reservation field is lower than the priority level of the transmission request packet.
When the transmission packet remains in the cue (as described in (3)(i)), the levels of P and R can be determined as follows:
P=max (R r , P m ), and
R=min (R r , and P m ).
Determining the levels of P and R in this manner has the advantage that the number of times of writing data in the reservation field is reduced because the data in the past circulation of the token remains in the reservation bits.
If is the above-described network priority determining method of the invention, in the case where a node exits from the cue of a transmission request packet after writing the priority level in the reservation field, a free token in which the priority level of the reservation field is shifted into the priority field circulates and all nodes have transmission request packets of lower priority, then the free token cannot be caught by the nodes, and therefore the circulation of the free token is continued. This difficulty may be eliminated by the following two methods:
(1) Control of the node which has transmitted the free token is utilized:
When the node outputs the free token, its level is stored in a register. The content of the register is reset when a busy token or a free token different in priority level is received. If, when a free token having the same priority level (other than the lowest priority level) is received before the register is reset and the priority level of the transmission request packet is lower than that of the free token, a new token is transmitted which has in its priority field the higher of the level of the reservation field of the free token and the priority level of the transmission request packet, and in its reservation field the lowest priority level. Accordingly, a free token having a priority level other than the lowest level of priority circulates continuously, which prevents the difficulty that, in other nodes, a packet lower in priority level is caused to wait for transmission.
(2) Monitor node is utilized;
A monitor node is provided in the network which detects when a free token whose priority is other than the lowest possible priority level has passed through the monitor node at least twice. In one example of such detection, whenever a free token whose priority is other than the lowest level passes through the monitor node, the content of the counter is increased by one, and when a busy token or a free token having the lowest priority passes through the monitor node, the counter is reset. Thus, when the content of the counter reaches a predetermined value (two), the circulation of a free token whose priority is other than the lowest level is detected. Upon detection of the circulation of this free token, similar to (i) above, the level of the reservation field is compared with the level of the priority of the transmission request packet of the monitor node, and a new free token is transmitted which employs the higher of the two values as the level in its priority field and which has in its reservation field the lowest priority.
FIG. 3 shows an example of a network priority level determining system according to this invention. In FIG. 3, three registers 11 hold the latest token's priority level and reservation field level, and a transmission request packet's priority level.
Two comparators 15 compare the level of P m with the levels of P r and R r . A priority control circuit 16, receiving the outputs of the comparators 15 and a token output timing control signal, determines the levels of the priority level P and the reservation field level R of a token to be transmitted. Data selectors 12 select the levels of P and R in response to selection signals provided by the priority control circuit 16.
In outputting a free token, the output of the second comparator 2 is checked, and the first data selection is controlled so that, if P m >R r , the level of P m is provided as the level of P, and if P m <R r , the level of R r is provided as the level of P. At the same time, the second data selector is controlled to determine the level of R. When P m >P r , the level of P r is outputted as the level of R. When P m <P r , the level of P m is outputted as the level of R. (In the algorithm in which the level of R is put at the lowest place, R=0 is outputted.)
In the case of a busy token, the level of P r is outputted as the level of P, when P m >R r the level of P m is outputted as the level of R, and when P m <R r the level of R r is oututted as the level of R.
As is apparent from the comparison of the system of the invention with the conventional system, in the system of the invention, the number of comparators is smaller, the priority control circuit is simpler, and it is unnecessary to use stacks. That is, the system of the invention is much simpler in circuit arrangement than the conventional system.
In the network priority determining system of the invention, a node outputs a free token according to the levels of R r and P m , and therefore the priority level can be inceased or decreased immediately. Accordingly, the system of the invention requires a shorter time for changing the priority levels than the conventional system in which a stacking station changes the degree of priority. Furthermore, since it is unnecessary to use stacks in the system of the invention, the hardware is considerably simplified.
A second embodiment of the invention will now be described. In accordance with this embodiment, the priority level of a free token is determined according to the following methods:
I. Describing the priority level one step at a time:
(1) When a node which has caught a free token and transmitted a data packet outputs a new free token, its priority is set to the highest available level.
(2) In the case where a free token having the highest available priority has circulated through the nodes and returned to the node which outputted the free token, namely, in the case where a busy token or free token whose priority level is other than the highest level have not been received, a free token whose priority level is next to the highest level is outputted.
(3) If the free token returns to its home node, the above-described operation is carried out until the priority level reaches the lowest available level.
If collection of reservation data is taken into account in outputting the free token of the highest priority, the following system is employed:
II. Using reservation data during circulation of a free token:
(1) When a node which has caught a free token and transmitted a data packet outputs a new free token, its priority is set to the highest available level, and the level of the reservation field is employed as the lowest priority level or the highest priority level of the transmission request packet of the node.
(2) When a free token of the highest priority level has circulated through the nodes and returned to its home node, the level of the reservation field is compared with the level of the priority of the transmission request packet of the home node. When the level of the reservation field is higher, the free token is transmitted with the level of the reservation field as its priority level. When the level of the priority of the transmission request packet is higher, the packet is transmitted.
A system of determining the priority level according to the second embodiment of the invention (hereinafter referred to as "system A") will be described.
A. (1) A free token has a priority field. Whenever each node receives a free token, the level from this field is written in register P r .
(2) When the priority level P m of a transmission request packet of a node is higher than that of a free token, the free token is converted into a busy token, and the data packet transmitted.
(3) After the packet has been transmitted, the node outputs a free token. In this case, the priority of the free token is set to the highest level, and the node stores the transmitted priority level.
(4) When the node has received a free token whose priority level is equal to the transmitted priority level, namely, when the transmitted free token has returned to the node before a busy token or a free token whose priority level is other than the highest is received, the priority of the free token is decreased by one step and the free token is transmitted again. In this case also, the transmitted priority level is stored.
(5) Whenever the free token returns to its home node, its priority level is lowered to the next in sequence in the above-described manner.
(6) The stored priority level is reset when a busy token is received or when a free token of different priority is received.
(7) It is unnecessary to provide stacks.
(8) No reservation field is utilized.
If, in the above-described system, a reservation field is utilized in the circulation of the free token, and collection of the priority level data of the nodes is taken into consideration, then the following system (hereinafter referred to as "system B") may be provided:
B. (1) A free token has a priority level field and a reservation field, and whenever each node receives a free token, the levels thereof are stored as P r and R r .
(2) When a free token has a priority level P, and the priority of a transmission request packet of a node is higher than P, the free token is converted into a busy token, and the data packet is transmitted.
(3) The levels of P and R at the time of transmission of a free token after the transmission of the data packet are as follows:
(i) P: highest priority level available
(ii) R: lowest priority level available (or the priority level of a transmission request packet of a node). In this operation, the transmission of a free token of the highest priority is stored.
(4) When a node receives a busy token or a free token whose priority is different from that of the transmitted free token, that is, when a free token returns to the home node which has transmitted the free token, the level of P is reset.
(5) When a node has received a free token whose priority is equal to that of the transmitted free token before receiving a busy token or a free token whose priority is different, the following free token is transmitted:
(i) P: the higher of the reservation field level and the highest of the priority levels of transmission request packets of the node.
R: the lowest available priority level (or the lower of the reservation field and the priority level of a transmission request packet of the node).
In this operation, the transmission of the free token of the highest priority is stored.
(6) Whenever the transmitted free token returns to its home node, the operation described in paragraph (5) is carried out.
(7) It is unnecessary to provide stacks.
The above-described system, being free from the operation of lowering the priority one step at a time, is effective in the case where it is required to greatly change the level of priority; that is, in such a case, the priority can be changed in a much shorter period of time.
The processing time can be further reduced by changing (5) above as follows:
When a node receives a free token whose priority is equal to that of the transmitted free token before receiving a busy token or a free token whose priority is different, the following operations are carried out:
(a) When the level of the reservation field is higher than the level of a transmission request packet of the node, the following free token is transmitted:
(i) P: the level of the reservation field
(ii) R: the lowest priority level or the priority level of a transmission request packet of the node.
(b) When the level of the reservation field is lower than the priority level of a transmission request packet of the node, the data packet is transmitted. After the transmission of the data packet, transmission of a free token is carried out (The operation described B. (3) above is carried out.)
FIG. 4A shows an example of an implementation of system A. In this figure, a register 11 holds the latest free token's priority level and reservation field level, and a transmission request packet's priority level. A comparator 25 compares the level of P m with the level of P r . A priority control circuit 26 receives the output of the comparator 25 and a token input/output timing control signal and in response outputs a selection signal for determining the priority level P of a token to be transmitted. In accordance with the selection signal provided by the priority control circuit 26, a data selector 22 selects the level of P. A memory register 27 temporarily stores the level of P. In the case where a free token is outputted after a data packet has been transmitted, the priority control circuit cause the data selector to output the highest priority level P max . When a free token transmitted by a node is returned to the node, the priority thereof is returned to the next lower level. The levels for a transmitted free token are stored in the memory register 27, and the latter is reset when a busy token is received or a free token whose level of priority is different.
The comparator 25 is used when, at the time of receiving a free token, it is determined whether or not the data packet can be transmitted, and the free token is converted into a busy token. (A free token/busy token control signal is set to the busy-token state.)
FIG. 4B shows an example of an implementation of system B discussed above. In FIG. 4B, a register 31 holds the latest free token's priority level and reservation field value, and a transmission request packet's priority level.
A comparator 35 compares the level of P m with the levels of P r and R r . A priority control circuit 36 receives the outputs of the comparator 35 and a token output timing control signal and in response outputs a selection signal for determining the priority level P and the level of the reservation field R of a token to be transmitted. A data selector 32 select the levels of P and R in response to a selection signal outputted by the priority control circuit 36. A memory register 37 temporarily stores the level of P.
When a free token is outputted after the transmission of a data packet, the first data selector (1) is set to output the highest priority level P max . When a free token has returned to its home node which transmitted the free token, the output of the second comparator (2) is checked, and the data selector (1) is set so that it outputs the level of P m as P when P m >P r , and outputs the level of R r as P when P r <P m . At the same time, the second data selector (2) is controlled to determine the level of R.
When P m >R r , the level of R r is selected, and when P m <R r , the level of P m is selected. If the level of R is held at the lowest possible level at all times, the second data selector (2) can be eliminated.
The level for the transmitted free token is stored in the memory register 37, which is reset by the priority control circuit when a free token of different priority or a busy token is received.
The second comparator (2) is used also when, at the time of receiving a free token, it is determined whether or not a data packet can be transmitted and the priority level control circuit changes the free token to a busy token. (The free token/busy token control signal is set to the busy mode.)
As is apparent from the above-description of FIGS. 4A and 4B, in the system of the invention, the number of comparators is smaller and the priority control circuit is simpler than those in the conventional system. Especially, in the system of the invention, unlike the conventional system, no stacks are used. That is, the system of the invention is much simpler in arrangement than the conventional system.
The embodiment of the invention has the following advantageous effects:
(1) Even when the size of a transmitting packet is large compared with the speed of transmission of the network, because the highest level of priority is employed in outputting the free token, a transmitting packet of highest priority is always transmitted first.
(2) When system B is employed, the reservation field also is used. Therefore, the time required for decreasing the priority successively is reduced.
(3) It is unnecessary to perform a processing operation with respect to a busy token. Therefore, no mechanism or time for processing a busy token is required.
A third embodiment of the invention will now be described.
(1) A token used in this embodiment has a priority control field P c . This field is used for indicating the priority level of the network in the case of free token, and it is used for reservation in the case of a busy token.
(2) When the priority level P m of a transmission request packet of a node is larger than the priority level P of a free token, the free token is converted into a busy token to effect the transmission of data.
(3) After transmitting the packet, the node outputs a free token. In this operation, the level of P c is determined as follows (here, R r is the level which is obtained by circulating the busy token; other symbols are the same as above):
(i) When a node has a transmission data packet,
P c =max (P r , P m ).
(ii) When a node has no transmission data packet,
P c =P r .
(4) Changing of the level of priority is not stored. Accordingly, no stacks are provided.
(5) The priority control field of the busy token is changed only when the priority level of the transmission request packet is higher than that of the priority control field.
As is apparent from the above description, when a node outputs a free token, the level of P c is determined according to the levels of P r and P m . Therefore, in the system of the third embodiment of the invention, compared with the conventional system in which a stacking station is used to determine the level of the priority control field, the time required for changing the priority is short and the hardware is simple since the stacks are eliminated. Furthermore, since the priority control field is used both for indication of the priority of the network and for reservation, the number of bits in the frame can be halved.
As is clear from the above description, if, when a node leaves the cue of a transmission request packet after writing the priority level in the reservation field and a free token, into the priority level field to which the priority level of the reservation field has been transferred, circulates through the network, the priority levels of transmission request packets of all the nodes are lower than that of the token being circulated, and hence the free token is continuously circulated through the network without being caught.
This difficulty can be eliminated by the following methods:
(i) When the node outputs the free token, its value is stored in the register. The content of the register is reset when a busy token or a free token of different priority is received. If, when a free token having the same priority (other than the lowest priority) is received before the register is reset and the node has a transmission request packet, a new free token having the same priority is transmitted, and if, under the same condition, the node has no transmission request packet, a free token having the lowest available priority is transmitted.
(ii) A monitor node is provided in the network which detects when a free token whose priority level is other than the lowest possible priority level has passed through the monitor node at least twice. In the example of the detecting method, whenever a free token whose priority is other than the lowest passes through the monitor node, the content of the counter is increased by one, and when a busy token or a free token having the lowest priority passes through the monitor node, the counter is reset. Thus, when the count value of the counter reaches the predetermined value (two), the circulation of a free token whose priority is other than the lowest is detected.
Immediately upon detection of the circulation of this free token, a free token is transmitted as follows: If, as in (i) above, the monitor node has a transmission request packet, a free token whose priority control field is made to have the level of priority of the packet is transmitted, and if the monitor node has no transmission request packet, a free token whose priority control field is made to have the lowest priority is transmitted.
FIG. 5 shows the arrangement of an implementation of a priority determining system according to the third embodiment of the invention.
In FIG. 5, registers 4 hold the priority level P m of the latest free token, and the priority level of a transmission request packet. A comparator (1) of a pair of comparators 45 compares the level of P m with the level of P r , and a comparator (2) compares the level of P m with the level of R r . A priority level control circuit 46 receives the outputs of the comparators and a token output timing control signal and in response outputs a selection signal for determining the priority level P and the level R of the reservation field of a token to be transmitted. A data selector 42 receives the selection signal from the priority level control circuit and in response sets a priority level control field P c .
In outputting a free token, the output of the comparator (2) is checked, and the data selector is controlled so that if P m >R r , the level of P m is outputted for P c , and if P m <R r , the level of R r is outputted for P c .
In outputting a busy token, for the level of the priority level control field P c :
(i) the lowest priority level P 0 is outputted, or
(ii) when the node has a transmission request packet, its priority level P m is outputted.
FIG. 2 shows an example of a token frame in the conventional system, and FIG. 6 shows an example of a token frame in the system of the invention. As is apparent from a comparison of FIGS. 2 and 6, the capacity of the priority control field in the system of the invention can be half the capacity of the priority control field in the conventional sytem.
In the priority determining system of the third embodiment of the the number of comparators is small and the priority control circuit is simple compared with the conventional system. Furthermore, in the system of the third embodiment of the invention, as in the case of the first and second embodiments, it is unnecessary to use stacks. That is, the system of the invention is much simpler than the conventional system. In addition, the number of bits used for priority control can be half that of the conventional system.
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A network priority determining system in which the percentage of utilization of the network transmission medium is significantly increased and the number and complexity of hardware components is reduced. When the network is not being used for transmission of data packets, a free token is circulated having a priority controlling field and a reservation field, while when the network is to be used for transmission, a busy token is circulated. To begin transmission, a network can catch a free packet if its priority level is equal to or less than that of the free token. The reservation field value and priority field value contained in the free token may be set in accordance with a reservation value of the previously circulated busy token.
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CROSS-REFERENCE
This application claims the benefit of provisional patent application Ser. No. 60/625,359 filed Nov. 6, 2004.
TECHNICAL FIELD
The process of this invention uses a unique combination of steps to produce glass ceramic billets for use in making semiconductor dopant sources. The resulting billets may be tailored to provide a variety of desirable properties including B 2 O 3 evolution rates.
BACKGROUND OF THE INVENTION
This invention is an improvement over the method used in making glass-ceramics for semiconductor doping as described in U.S. Pat. Nos. 3,907,618, 3,962,000, 3,998,667 and 4,282,282. The disclosure of these patents is herein incorporated by reference. These patents describe a material and a method to make a glass-ceramic material by first melting a special glass composition at a high temperature, casting it into a round billet, cooling it to room temperature and then partially crystallizing the glass by passing the glass billet through a heat treatment cycle. The treated billets are then turned round and cut into thin wafers for use as planar diffusion sources for doping silicon wafers in semiconductor production. In addition, U.S. Pat. No. 5,145,540 describes a CIP process for sintering powders to make ceramic bodies. The method combines 40-90% oxides and 10-60% of a glass powder. The process of this invention differs in that billets are made of glass powders containing up to about 10% oxide additions.
In planar diffusion doping, a planar (i.e., flat) surface of a solid dopant host and a planar surface of a silicon wafer to be doped are positioned close and parallel to each other during the diffusion cycle. The ceramic wafer evolves B 2 0 3 which deposits on the silicon wafer during the diffusion cycle. The B 2 O 3 then reduces to boron which in turn diffuses into the silicon wafer to create a semiconductor device.
The above four US patents give many compositions from the RO—Al 2 0 3 -B 2 0 3 -SiO 2 system were RO is one or more alkaline earth oxides (BaO), MgO, etc.). The compositions that can be melted, cast into billets, cooled to a relatively low temperature or to room temperature, and then passed through a heat treatment cycle to partially crystallize the glass in a controlled manner into what is known as a glass-ceramic. A major criteria for the glass-ceramic process is to select a composition that does not devitrify (uncontrolled crystallization) when it is cast into billets and is cooled. If any uncontrolled crystallization occurs, the final billet will contain relatively large crystals that can cause problems in semiconductor processing. These problems can include trapping impurities during cutting of the planar diffusion sources which evolve during use or can include breaking of the source during use because of stresses concentrating at the crystal. The larger the diameter of the billet to be cast, the more difficult it is to cool the glass billet without devitrication. It is therefore becoming very difficult to meet the demands of the semiconductor industry for large diameter planar diffusion source using the glass-ceramic process. These problems are overcome using the “fused glass powder” process of this invention.
It is possible to adjust the glass compositions so that large diameter glass billets can be cast and cooled to room temperature without devitrification. However, these more stable compositions do not produce planar diffusion sources that are rigid enough when the billets are heat treated and cut into planar diffusion sources for use in semiconductor doping. These planar diffusion sources quickly warp during use making them unusable. My “fused glass powder” process overcomes these problems.
SUMMARY OF THE INVENTION
This invention is a method to produce ceramic billets of a variety of shapes and sizes from powders made from a variety of glass compositions by fusing the powders together into a dense ceramic billet using a heat treatment cycle. The powders may be made from melted glass. The powders may be made from melted glass poured between rollers to make ribbon or poured into water to make cullet for ball milling. Water-quenched cullet grinds differently from ribbon quenched between water-cooled rollers. Powder from either method, however, has been found to work well in this invention. Preferred glass compositions are selected from the following components:
Components
Mole %
SiO 2
40-60
Al 2 O 3
10-30
B 2 O 3
15-45
BaO
1-15
RO
3-20
Where RO is selected from BaO, MgO, CaO, SrO and mixtures thereof. Where the mole ratio Al 2 0 3 /RO=1.5-9.0.
More preferred are the glass compositions that are selected from the following components:
Components
Mole %
SiO 2
35-55
Al 2 O 3
15-25
B 2 O 3
15-45
BaO
2-6
MgO
2-6
Where the mole ratio Al 2 0 3 /BaO+MgO)=1.5-5.0.
The billets are made by heat treating glass powders and preferably are made by adding 0-4% water to glass powders as a binder. The ceramic materials of this invention should not be confused with glass ceramics. “Glass-ceramics” has a special meaning. The melt is cast as a glass. The glass is then heat treated and crystallized in a controlled manner.
Prior to heat treatment, the powdered glass is made into a billet using one of the following methods:
1. Putting loosely packing glass powders in a ceramic crucible and heat treating the powder. 2. Isostatic pressing the powders and heat treating the pressed powder. 3. Axial pressing the powders in a ring and piston mold. Heat treating the pressed powder follows this step.
The powders may be made from more than one composition. The different compositions may be located in the billet so as to produce different B 2 0 3 evolution rates at different positions across the diameter of a wafer cut from the billet. The powders of the different compositions and up to 10% of stable oxides such as Al 2 O 3 or SiO 2 are blended to produce sintered materials that have different properties than any of the individual compositions.
The heat treatment cycle has a low fusion temperature for initial sintering followed by a high sintering temperature for densifying the powder into a solid billet. Preferably, the heat treatment cycle has a low fusion temperature around 750° C.-850° C. and a high sintering temperature around 1000°-1200° C. One embodiment stacks the pressed billets in the heat treatment furnace so that they will stick together during the heat treatment cycle. The billets are cut into planar diffusion wafers for use in semiconductor production. The final application may include the following embodiments:
1. Concentric cylinder with one composition in the center and a different one on the outside. 2. Blended powders of two or three or more different compositions. 3. Blended powder of one or more compositions with up to 10% Al 2 O 3 , SiO 2 or other similar stable oxides as an additive.
Other objects and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description of the preferred embodiments and the accompanying drawings.
DETAILED DESCRIPTION OF THE INVENTION
The prior art provides for compositions that can be made into 3″ diameter planar diffusion sources that have improved resistance to warpage over those disclosed in previous patents when cycled between 900° C. and 1050° C. The need for even larger diameter planar diffusion sources (now up to 6″ in diameter and even larger) for use at temperatures at and above 1150° C. have made even these compositions difficult to manufacture into large glass billets without devitrification. The new “fused glass powder” process overcomes this problem. The glass melts must also be made very homogeneous when cast into glass billets in the glass-ceramic process of this invention. Otherwise, the cord (streaks of non-uniform glass) in the final planar diffusion sources may create problems with the sources (breakage) or with the manufacture of semiconductor devices. Since these RO—B 2 O 3 —Al 2 O 3 —SiO 2 compositions can dissolve many refractory crucibles (i.e., fused silica), it is difficult to eliminate the cord originating from the crucible when they are melted in refractory crucibles. Consequently, these melts are usually made in large platinum crucibles with platinum stirrers which, of course, are very expensive resulting in very high manufacturing costs.
The new “fused glass powder” process of this invention overcomes this problem and permits fused silica, alumina or similar refractory crucibles instead of platinum crucibles to be used for melting. This “fused glass powder” invention provides a method to make high quality large diameter billets for cutting into planar diffusion sources utilizing compositions that can be used with the glass-ceramic process. The invention also provides a method to make high quality large diameter billets with compositions that cannot be used with the glass-ceramic process because the glass billets might devitrify or partially devitrify during cooling. The invention also permits melting in silica, alumina or similar refractory crucibles which are much less expensive than platinum crucibles often used in the glass-ceramic process. The prior art provides for a wide range of compositions in the BaO—MgO—B 2 O 3 —Al 2 0 3 —SiO 2 system. The manufacture of planar diffusion sources utilizing the following examples illustrates how the new “fused glass powder” invention provides significant improvement and unexpected results over the prior method of manufacturing planar diffusion sources.
Example 1
In a specific example of the invention, the following composition was melted in a fused silica crucible at about 2900° F.
Component
Mole %
wt %
SiO 2
46.3
37.0
Al 2 O 3
20.7
28.0
MgO
3.73
2.0
BaO
4.92
10.0
B 2 O 3
24.3
22.5
Cl 2
0.5
0.5
Al 2 O 3 /RO
2.4
This glass could also be melted in a platinum crucible, cast into billets and processed according normal procedures utilized in the glass-ceramic process. However, in this example, the glass was melted in a silica crucible and cast between water-cooled rollers to make ribbon. The ribbon was ball milled to make a powder having a screen fraction of about −80. The powder was then made into a billet using the technique described below. A technique to make the billet from this composition was to loosely pack the powder into a 2½ ″diameter×2″ high Al 2 0 3 crucible having a thin layer of Al 2 0 3 powder on the bottom. The Al 2 0 3 powder insures that the ball milled powder will not stick to the crucible. The crucible filled with powder was placed in a heat treatment furnace and given the following heat treatment cycle:
Ramp from room temperature to 750° C.
Hold at 750° C. for about 16 hrs.
Ramp to 1150° C.
Hold 1150° C. for 2 hours.
Ramp to room temperature.
The “fused glass powder” billet pulled away from the walls of the Al 2 0 3 crucible and was easily removed from the crucible. The “fused glass powder” billet was cut open and surprisingly was found to be very hard having the typical appearance of a billet made through the glass-ceramic process. Since the powder was not pressed, the material was much less dense than if it were made as a glass-ceramic material. This process permits a lighter dopant source to be made which is desirable and easier to handle by manufacturing personnel.
A wafer cut from this “fused glass powder” billet was then placed in the diffusion furnace and was used to periodically dope a silicon wafer for 1 hour in nitrogen at 1100° C. Four silicon wafers were doped over the hours that the source was held at 1100° C. The color of the deposited glass on the four doped silicon wafers was blue to yellow indicating a deposited B 2 0 3 glass film thickness of about 1200 angstroms. This is about the thickness of the glassy film that is obtained from planar diffusion sources of this composition made with the glass-ceramic process. The sheet resistivity of the four doped silicon wafers was about 2.9 ohm/sq. This is also close to the sheet resistivity that is obtained from planar diffusion sources of this composition made with the glass-ceramic process. These results show that the material from the “fused glass powder” process evolves B 2 0 3 at an acceptable rate for at least 105 hours at use temperatures near 1100° C.
Example 2
In a second specific example of the invention, the following composition was melted in a fused silica crucible at about 2900° F.:
Component
Mole %
wt %
SiO 2
48.3
38.6
Al 2 O 3
21.6
29.3
MgO
3.9
2.1
BaO
5.2
10.6
B 2 O 3
21.0
19.4
Al 2 O 3 /RO
2.4
This glass could also be meted in a platinum crucible, cast into billets and processed according normal procedures utilized in the glass-ceramic process. However, this glass composition is much more difficult to make than the glass in Example 1 and is therefore more prone to devitrification. In this example, the glass was melted in a silica crucible and was cast between water-cooled rollers to make ribbon. The ribbon was ball milled to make a powder having a screen fraction of about −80. The powder was then made into billets using various techniques which includes the two examples below.
The first technique to make a billet with the powder from Example 2 was to add 4% deionized water to the powder and press the powder into two billets 1.5″ diameter and 1″ long in a Carver axial press with about 10,000 lbs pressure. The green strength of the pressed billets was good, the billets were hard, and they were easy to handle without crumbling. These billets were then placed on top of each other and heated to 750° C. for about 2 hours. When cooled to room temperature, surprisingly, the “fused glass powder” billets were hard and stuck together. This fusion is desirable because it is easier to cut a long billet into wafers on a ceramic saw than several small billets. The heat treating of the billets then continued with the following heat treatment cycle:
Ramp from room temperature to 750 C
Hold at 750 C for about 16 hrs
Ramp to 1065 C
Hold for 1 hr
Ramp to 1150 C
Hold at 1150 C for 2 hrs
Ramp to room temperature
The “fused glass powder” billet was first held at 750 C for 16 hrs because this is the temperature where the powders initially stick together and the billet begins to shrink. The billets were held at 1065 C for one hour because a sample of this material that had been run in a dilatometer showed that significant shrinkage occurred near this temperature. Obviously, this is the temperature for this composition where the glass powders fuse together into a dense “fused glass powder” billet.
When the billets were removed from the heat treatment furnace, the “fused glass powder” billets were very hard, more dense than the billet obtained in Example 1 and stuck together. The inside of the “fused glass powder” billets, surprisingly, looked like a glass-ceramic billet that might have been made using the glass-ceramic method.
Example 3
The second technique to make a billet from the powder of Example 2 is to add 4% deionized water to the powder and cold isostatically press (CIP) the powder into a 4.5″ diameter by 2″ long billet at about 36,000 psi. The green billet was then heat treated according to the following heat treatment cycle:
Ramp from room temperature to 750° C. at about 1° C./min.
Hold at 750° C. for about 16 hrs.
Ramp to 1065° C. at about 1° C./min.
Hold for 1 hour.
Ramp to 1150° C. at about 0.5° C./min.
Hold 1150° C. for 2 hours.
Ramp to room temperature at about 0.5° C./min.
When the “fused glass powder” billet was removed from the heat treatment furnace, it was hard and more dense than the billet obtained from the first technique of example 2 and again resembled a billet that might have been made through the glass-ceramic route.
One skilled in the art might expect the powders of these examples to stick together when heat treated to a high temperature. However, it was unexpected to see the material to initially fuse together at a low temperature (near 750° C.) and then dramatically densify at a high temperature (1065-1150° C.) to such an extent that it resembles a source made through the conventional glass-ceramic route. It was also unexpected to observe the sources made through this “fused glass powder” process to dope silicon wafers similar to those made through the conventional glass-ceramic process, even though they exhibited different densities.
Other advantages of this “fused glass powder” process over the glass-ceramic process are as follows. The “fused glass powder” process would break up any cord in the glass originating from silica crucibles and uniformly disperse it throughout the powder during ball milling. This permits the use of fused silica or similar ceramic crucibles and eliminates the need for using expensive platinum crucibles.
Since the glass is rapidly quenched between rollers, the “fused glass powder” process permits very unstable and very rigid glasses containing Al 2 0 3 /RO mole ratios of over 3.0 to be made. Compositions having these higher Al 2 0 3 /RO mole ratios can be quenched into glass ribbon between rollers, ball milled into powders and made into “fused glass powder” billets according to the procedures outlined above. These compositions would produce planar diffusion sources that would exhibit even better warpage resistance during use at high temperatures than those shown in examples 1, 2 & 3.
In addition, the above described method of making “fused glass powder” billets also permits melting the glass in less expensive refractory crucibles for a much shorter melting time. The “fused glass powder” method of processing the glass permits making shapes other than round such as square planar diffusion sources for use in doping solar cell silicon. The “fused glass powder” method also permits combining more than one composition in a billet to obtain special B 2 O 3 evolution rates at different positions such as the edges of the planar diffusion source. The “fused glass powder” method also permits inclusion of high purity Alumina and/or silica fibers to further increase its strength and resistance to warpage during use. The “fused glass powder” method also permits blending powders of different compositions or other oxides such as Al 2 O 3 , SiO 2 or other relatively stable oxides as solid particles or as bubbles to adjust properties such as resistance to warpage, density, B 2 O 3 evolution rate, and the like.
In summary, the above “fused glass powder” process overcomes the shortcomings of the conventional glass-ceramic process and produces a planar diffusion source exhibits properties that are equivalent or better than those made by the glass-ceramic process. Very unstable compositions that cannot be made into large diameter billets using the glass-ceramic process can be made into very good billets using the “fused glass powder” billets. These billets will exhibit a hard material that can be cut into wafers which will exhibit superior warpage resistance. Almost any diameter or shape of planar diffusion sources can be made using the “fused glass powder” process with CIP, axial presses and/or even lose-packed crucibles.
The above detailed description of the present invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims.
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This process is a fused glass powder process for making ceramic billets for semiconductor dopants. The powder process uses a unique combination of steps for packing, compacting and heat treating the powders. The resulting billets may be tailored in composition to provide a variety of densities, rigidities and B 2 O 3 evolution rates. Further, the resulting wafers have a large diameter to meet the needs of semiconductor production.
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[0001] This application is a Divisional of co-pending U.S. application Ser. No. 14/336,581 filed Jul. 21, 2014, which claims priority to U.S. Provisional Application Ser. No. 61/875,402 filed Sep. 9, 2013, each of which is expressly incorporated by reference herein in their entirety. This invention was made with government support under Grant No. 60NANB11D174 awarded by NIST-BFRL Extramural Fire Research Grants Program. The government has certain rights in the invention.
TECHNICAL FIELD
[0002] The present application relates to coatings, and methods for preparing the coatings, which can be applied to a variety of surfaces and/or materials, the coatings providing a flame retardant function or characteristic to the surface and/or material. Specifically, in certain embodiments, the coatings are derived from biological materials, such as dopamine, phytic acid, and melamine.
BACKGROUND
[0003] Broadly defined, there are generally 5 main classes of flame retardants: metal oxides, hydroxides, and hydrates; halogens; (organo)phosphorus compounds; inorganic fillers; and intumescing materials. Regardless of the type of flame retardant, they generally follow one (or a combination) of three mechanisms for reducing fire hazards: vapor phase inhibition, solid phase char formation, and quenching/cooling.
[0004] For vapor phase inhibition materials, the flame retardant additive reacts with the burning material, such as a polymer, in the vapor phase. The vapor inhibition materials disrupt the production of free radicals at a molecular level and shut down the combustion process. This mechanism is commonly used with halogenated flame retardant systems. Char-forming flame retardant additives modify the decomposition pathway of the burning material by promoting the formation of a solid residue (char) on the material's surface and decreasing the amount of combustible volatiles. This char layer insulates the material, slowing pyrolysis, and creates a barrier that hinders the release of additional gases to fuel combustion. This method is commonly deployed by inorganic acids or acid precursors (e.g., phosphate salts) that induce crosslinking between, for example, polymer chains of the burning material. Nitrogen compounds, e.g. melamine, can be used in combination with phosphorous containing flame retardants to promote the formation of a porous char with enhanced thermal insulation and thermal stability through a synergistic mechanism observed when P—N bonds form prior to or during combustion.
[0005] Hydrated minerals are often used as halogen-free flame retardant systems commonly used for extruded applications like wire and cable. During combustion, the hydrated materials participate in an endothermic reaction to release water molecules that cool the burning material and dilute the combustion process.
[0006] The char forming mechanism can be enhanced by choosing compounds that intumesce. Intumescent compounds are insulating char forming materials that reduce heat and oxygen transport between the flame and unburned fuel source. In various embodiments, intumescent materials are comprised of (a) an acid source, which dehydrates, for example, a carbon source and/or the substrate, and is typically a phosphorus compound, such as ammonium polyphosphate, and (b) a carbonization agent or carbon source which chars during decomposition. Pentaerythritol and its derivatives have been most commonly used as a carbon source. The intumescent material may additionally comprise a blowing agent, which generates gas during decomposition. Blowing agents generally comprise a nitrogen compound. Melamine or urea have been used as blowing agents. In some embodiments, the blowing agent may be part of the acid and/or carbon source, for example, when the acid and/or carbon source contains N-containing groups, such as ammonium polyphosphate.
SUMMARY
[0007] In one aspect, a coating composition comprising poly(dopamine) and either tris(hydroxymethyl)aminomethane or gaseous ammonia is provided. In various embodiments, the poly(dopamine) is substantially water insoluble. The coating composition can further comprise at least one additional component selected from the group consisting of melamine, a cationic clay, a phosphorus-containing compound, sulfur-containing compound, an amine-containing compound, aluminosilicates, silicon oxides, and combinations thereof. In various embodiments, the coating composition is an intumescent composition.
[0008] In accordance with a particular aspect, an article comprising a substrate and the described coating composition is provided, where the substrate comprises glass, metal, wood, synthetic polymer, natural fiber, or other flammable and/or combustible material.
[0009] In accordance with another aspect, a method for preparing the coating composition is provided, comprising mixing dopamine with tris(hydroxymethyl)aminomethane at a pH greater than 7 or subjecting dopamine to gaseous ammonia under conditions to form poly(dopamine) comprising both water insoluble and water soluble fractions, and subjecting the formed poly(dopamine) to dialysis or centrifugation to remove substantially all the water soluble fraction.
[0010] Other aspects include methods for increasing flame retardant properties of a substrate, the method comprising either forming the coating composition and applying the coating composition to a substrate, or applying dopamine to a substrate, and subjecting the dopamine to an alkaline condition, under suitable conditions, to form a poly(dopamine) comprising water soluble and water insoluble fractions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1A and 1B are pictures of the residues after microcombustion calorimeter for dopamine (DOPA) (left), AMPA (Center) and DOPA+AMPA on the right, with FIG. 1A a side view and FIG. 1B a top view.
[0012] FIG. 2 shows x-ray analysis of a DOPA containing composition.
DETAILED DESCRIPTION
[0013] The following detailed description will illustrate the general principles of the invention, embodiments of which are additionally provided in the accompanying examples.
[0014] Dopamine Polymerization
[0015] Dopamine (4-(2-aminoethyl)benzene-1,2-diol) (DOPA), when placed in an alkaline aqueous solution of about pH 8 to about 10, and particularly a pH of about 8.5, self-polymerizes and adheres to a wide variety of substrates, regardless of polarity, including inorganic materials, such as glass, minerals, etc., synthetic polymers, such as Teflon, polyethylene glycol (PEG), etc., and natural polymers, such as cellulose, chitosan, etc. In one embodiment, a composition comprising dopamine, and any additional components described, is polymerized using tris(hydroxymethyl)aminomethane (Tris) at an alkaline pH. In another embodiment, a composition comprising dopamine, and any additional components described, is polymerized using ammonia gas. The poly(dopamine) composition can be applied to a substrate to impart flame retardant characteristics onto the substrate.
[0016] Alternatively, dopamine, and optionally any of the described additional components, can be applied to the substrate and subsequently subjected to polymerization conditions. The adhesion of dopamine, during the polymerization process, to a substrate, is promoted by the formation of covalent bonds with the substrate, as well as other strong intermolecular interactions, such as hydrogen-bonding, metal chelation, and π-π interactions. In various embodiments, dopamine is combined with the substrate to be coated, and subjected to alkaline conditions to induce polymerization of the dopamine, as well as facilitating adhesion of the poly(dopamine) coating to the substrate. In additional embodiments, dopamine can be polymerized prior to coating the substrate, depending on the type of substrate to be rendered as a flame retardant. In various embodiments, the polymerized dopamine or the monomeric dopamine composition may contain additional components which facilitate adherence or binding or association of the poly(dopamine) and/or monomeric dopamine composition to the substrate. In one example, the poly(dopamine) contains a clay component.
[0017] There is significant debate over the exact mechanism of dopamine polymerization, but there are two well accepted models. In both cases, the alkaline solution oxidizes the dopamine to a mixture of 5,6-dihydroxyindoline and its dione derivative. In one model, these two oxidation products polymerize and cross-link through the formation of covalent bonds. In the other model, a supramolecular aggregate forms between the two oxidation products through strong intermolecular forces, including charge transfer, π-stacking, and hydrogen bonding. Both mechanisms may actually be occurring. A Tris-HCl-based buffer system has been used in dopamine polymerization reactions to achieve the desired alkaline condition. However, we have found that the formation of insoluble poly(dopamine) does not work when using a borate-based buffer at the same alkaline pH. The structure of tris(hydroxymethyl)aminomethane (Tris) contains the same end groups that are found in dopamine, —OH and —NH 2 groups. Without being held to a single theory, it is believed that tris(hydroxymethyl)aminomethane participates, or is incorporated, at some level, in the cross-linked structure of poly(dopamine).
[0018] Furthermore, we have found that poly(dopamine) actually consists of a water soluble and a water insoluble fraction, which can be separated by dialysis and/or centrifugation. It is likely that the insoluble fraction consists of covalently linked monomers. In various embodiments, monomeric dopamine, and any optional components, is applied to a substrate and subjected to alkaline conditions, to form the water soluble and water insoluble fractions of poly(dopamine), to coat and impart flame retardant characteristics to the substrate. The coated substrate may be washed to remove the water soluble fractions. In other embodiments where poly(dopamine) is first created and then applied to a substrate, the substantially water insoluble portion of the poly(dopamine) composition may be applied to the substrate. Alternatively, the poly(dopamine) composition containing both water soluble and insoluble portions can be applied to the substrate, and the water soluble portion can be subsequently washed off. In yet other embodiments, the water soluble portion of poly(dopamine) is not washed off.
[0019] In various embodiments, a substrate coated with the poly(dopamine) composition is subjected to a further drying step. In one embodiment, the coated substrate is dried between 50° C. and 150° C. for 1 hour to 24 hours. In one embodiment, the coated substrate is dried at ≧80° C. The maximum drying temperature is limited by the thermal stability of the substrate. For example, coating of polyurethane foam substrates which were dried for at least 2 hours and 80° C. or 90 minutes at 110° C. produced suitable results.
[0020] Poly(Dopamine) Flame Retardant
[0021] Whether the poly(dopamine) is formed through covalent polymerization or strong physical attraction, poly(dopamine) forms a durable layer that can entrap additional molecules. These entrapped additional molecules can serve a variety of purposes, as described below. We found that after polymerization of dopamine, the water insoluble fraction of the product exhibits the best properties in terms of fire resistance, compared to the water soluble fraction, as demonstrated by microcombustion calorimetry, where the water insoluble fraction had a much lower heat of combustion. The water insoluble fraction is likely formed by highly irreversibly, cross-linked structures comprising covalent bonds, and not formed by hydrogen-bonding, metal chelation, and π-π interactions. The poly(dopamine) structure is comprised of unsaturated carbons, nitrogen atoms, and oxygen atoms, all of which promote the formation of char when heated.
[0022] In addition, the use of an additional drying step of the coated substrate is thought to render the poly(dopamine) coating more durable and increase adhesion properties by thermal annealing of the polymer to the substrate.
[0023] In one aspect, a flame retardant coating comprising poly(dopamine) is provided, with its primary flame retardant mechanism being the formation of a char layer. As stated earlier, charring and char layer stability of the coating can be enhanced through the use of P—N synergies, addition of aluminosilicates (e.g. clay or talc), or addition of silicon oxides (e.g. glass or polyhedral oligomeric silsesquioxane). In one embodiment, the described poly(dopamine) coating is an intumescent material and in various embodiments, wherein the poly(dopamine) provides a carbon source which chars during decomposition, and at least one of an acid source which dehydrates the substrate and/or the carbon source. In various embodiments, the acid source is a phosphorus compound or a sulfur-containing compound. Additionally, the composition may comprise a blowing agent, such as a nitrogen containing compound, which generates gas during decomposition. In some embodiments, one or both the carbon source and/or acid source also provides blowing agent characteristics, for example, by containing nitrogen.
[0024] To enhance the formation of the char layer by the poly(dopamine) coating, the addition of phosphorus and nitrogen rich compounds, and clays may be included in the composition.
[0025] Melamine (MLM) is a compound readily derived from urea, a natural, biological compound, that has been shown to contribute to char formation, enhance intumescing behavior, and produce ammonia, which acts as an inert diluent which functions as a quenching mechanism. In various embodiments, melamine is included in the poly(dopamine) coating.
[0026] Sodium montmorillonite is a natural, expandable, anionic clay with exchangeable cations. Other suitable 2:1 exchangeable anionic clays include smectites, such as saponite, beidellite, or nontronite, illites, and vermiculite. Like most aluminosilicates, sodium montmorillonite typically enhances the structural integrity of char during combustion of a carbon source. In one embodiment, prior to the formation of poly(dopamine), the sodium of the sodium montmorillonite can be exchanged with dopamine under acidic conditions, which following application to a substrate and subsequent alkaline conditions, should allow for cross-linking, as described above, within the layers of clay, having the advantageous effect of expanding the layers of clay. Topical applications of clay, including layer-by-layer assembly, onto a substrate are typically non-durable and removed through simple washings. The subsequent cross-linking of dopamine may improve durability of clay coatings used as flame retardants. In various embodiments, the poly(dopamine) coating comprises sodium montmorillonite or proton-exchanged montmorillonite.
[0027] Aminomethylphosphonic acid (AMPA) contains both a phosphate and an amine group (nitrogen containing group), which should enhance char formation and integrity. AMPA may also participate in the crosslinking of dopamine, as described above, and can also be co-exchanged with dopamine in montmorillonite samples. Similarly, 2-aminoethylsulfonic acid (taurine) contains both a sulfate and an amine group, which behaves similarly to AMPA under fire conditions. It, too, may participate in dopamine crosslinking. In various embodiments, the poly(dopamine) coating comprises AMPA or taurine.
[0028] We have also investigated the use of phosphorylated and aminated carbohydrates, such as glucosamine, fructose-1,6-bisphosphate, inositol phosphates and glucosamine-6-phosphate (GA6P), as alternatives to melamine and AMPA, or as additional additives. Phytic acid and glucosamine-6-phosphate (GlcN6P) are particularly suitable for inclusion into the poly(dopamine) coating. Phytic acid, also referred to as inositol hexakisphosphate, is a naturally occurring compound that is the principal storage form of phosphorus in many plant tissues. The high phosphate content should enhance char formation and may also add vapor phase inhibition, as phosphorus compounds may act in both the condensed and vapor phases. Also, two of the phosphate groups in phytic acid are quite acidic, with a pK of about 1.6, which should improve intumescent behavior and char strength. Phytic acid can also readily phosphorylate natural fibers, such as cellulose as the substrate. In addition, phytic acid can be partially neutralized with an amine-containing base, such as urea, guanidine, or an amino acid, so that it may participate in the poly(dopamine) cross-linked structure as well as add a gas-forming agent to the formulation. In various embodiments, the additional phosphate groups promotes interactions between the poly(dopamine) composition and the substrate, such as by covalent bonds, such that the described flame retardant coating becomes more durable. In various embodiments, the poly(dopamine) coating comprises a phosphorylated and aminated carbohydrate.
[0029] Like AMPA, GlcN6P has an amine group and a phosphate group. As described above, the presence of both groups will enable exchange of components of clay, such as the counter cation sodium, by protonating the amine group and potentially generate P—N synergies in the described. In various embodiments, the poly(dopamine) coating comprises GlcN6P.
[0030] GA6P also contains three hydroxyl groups, so it may participate in the cross-linking of dopamine, similarly to Tris, as described above, and could potentially be phosphorylated by treatment with phosphoric acid.
[0031] Since all of the above described phosphates are acidic, they can be mixed with dopamine without the danger of premature polymerization that may occur with more basic organophosphates typically used as flame retardants, such as triphenylphosphate or tris(1,3-dichloro-2-propyl) phosphate.
[0032] In various embodiments, known flame retardant materials can be added to the described compositions. For example, halogenated sugars, such as Sucralose, urea, guanidinium phosphate, and/or melamine phosphate may be included in the described compositions.
[0033] Spot Flame Test
[0034] In one case, flexible polyether foams (PUF) were exposed to a butane torch flame to test fire resistance. Foams were first soaked in dopamine, dopamine-melamine, or dopamine-AMPA in water/methanol (50/50 by mass) solutions and squeezed to remove excess liquid. Dopamine or dopamine containing mixtures were cross-linked by moving the foam into a sealed container containing ammonium hydroxide at 40° C. Methanol helps swelling the foam to promote diffusion of dopamine into the foam and generate an interpenetrating network of a charring dopamine polymer in the foam. The first samples were soaked and sonicated for 1 hour to promote diffusion of dopamine. The sonication resulted in an 18% increase in mass due to enhanced liquid pick-up. These samples exhibited a very good flame retardant effect, with no collapse of the foam and flame extinguishment with a Bunsen burner. Sonication was not performed on subsequent samples and these samples did not show very good results in the scaled-up cone calorimeter test, where the foam collapsed. It is not believed that the lack of sonication is necessarily the reason for the different behavior, but the extent of cross-linking between dopamine molecules, the other additives in the coating, and the PUF was certainly a factor.
[0035] Horizontal Burn Test
[0036] Horizontal burn tests were conducted to evaluate flame spread on foam samples. A 4 cm propane flame was used as ignition source. The flame impinged for 6 s on the foam sample on one extremity; the other extremity of the sample was clamped to keep the sample horizontal. The foam samples had a length of 110 mm and a cross-section of 25 mm by 25 mm. In this example, foams were coated with a thin water-based spray coating of dopamine, AMPA, sodium montmorillonite (NaMT), or a combination of AMPA and NaMT (1:1 mass ratio) or dopamine and NaMT (1:1 mass ratio) using an oil spray bottle. The solid content was 10% by mass and the volume was 15 mL in all spray formulations. The sample treated with dopamine only was sprayed again 2 h after the first application with 15 mL solution containing 0.97 g of TRIS buffer. In all other samples the crosslinking in the dopamine was promoted by the other additives. All samples were dried at 50° C. for 12 hours. These formulation were water based and no methanol was used. Methanol based formulation might be preferred for promoting the diffusion of dopamine into PUF and potentially increase the effectiveness of the coating. The uptake of sprayed material was reasonably not homogeneous throughout the sample; the concentration decreased moving from the surface of the foam towards the core of the foam. The control foams (no coating) burned completely after application of the ignition flame. All AMPA coated foams, by itself or in combination with dopamine and NaMT, did not burn after the removal of the ignition flame. Sustained and complete combustion was eventually observed after multiple ignition flame impingements once the flame reached the unprotected foam core.
[0037] The coating visibly melted and sloughed off the surface of the foam during burning, failing to establish a protective char. The use of NaMT produced a much more viscous fluid prior to application and adhered better to the surface of the foam during burning. The exterior of the foam was clearly protected with a char layer, retaining the shape of the foam, though the interior of the foam continued to burn to completion.
[0038] Microcombustion Test
[0039] Microcombustion tests were conducted on a wide-range of coating mixtures to assess prevention of heat release and visibly observe extent of intumescence upon combustion. The data in Table 1 show a potential synergy between dopamine with Na-MT and between dopamine and MLM. Dopamine is typically cross-linked using a 10 mM Tris-HCl solution (sample DOPA+Tris-HCl*). We found that Tris-HCl promotes cross-linking not only because it stabilizes the pH around 8.5, but also because hydroxyl groups in Tris-HCl can likely react with dopamine (DOPA). DOPA can also react with hydroxyl groups in NaMT and amine groups of AMPA. When the sample DOPA+Tris-HCl* is washed to remove the soluble fraction of the product, the obtained product (DOPA+Tris-HCl*Insol) has a high cross-linking density as indicated by the high residue, low THR (total heat released), and low HRC (heat release capacity). The control sample which was not cross-linked (DOPA) produces significantly less char and a higher heat release than any of the samples cross-linked with Tris-HCl.
[0000]
TABLE 1
Final residues, total heat evolved and heat release
capacity measured by microcombustion calorimeter.
The calculated theoretical data for a mixture based
on the single components are shown in parenthesis.
Residue
THR
HRC
Sample ID
(%)
(kJ/g)
(kJ/g)
PUF
0.3
25
510
DOPA
15.3
14.7
280
DOPA + Tris-HCl*
27
10.0
110
DOPA + Tris-HCl* Insol
58
1.1
13
AMPA
16.8
5.1
92
AMPA1 + DOPA1
39.8
(32.1)
9.2
(9.6)
174
(186)
AMPA1 + Tris-HCl 1
16.3
(8.4)
12.8
(11.3)
150
(248)
Tris-HCl
0.0
17.6
403
MLM
0.0
15.1
486
DOPA1 + MLM
19.3
(7.2)
6.3
(14.9)
128
(383)
DOPA1-NaMT 1
61.8
(51.1)
2.9
(7.4)
39
(140)
NaMT
86.9
0
0
DOPA1-AMPA1-NaMT 0.1
49.50
(19.4)
5.9
(9.4)
89
(177)
AMPA1-NaMT 1
72.0
(51.9)
2.8
(2.6)
52
(46)
MLM
0
15.1
390
DOPA1 + MLM1
19.3
(7.7)
6.4
(14.9)
128
(204)
AMPA + DOPA is a 1/1 mass ratio of AMPA and DOPA.
AMPA1 + Tris-HCl 1 is a 1/1 mass ratio of AMPA and Tris-HCl
AMPA1-NaMT 1 is a 1/1 mass ratio of AMPA and NaMT
DOPA1-AMPA1-NaMT 0.1 is a 1/1/0.1 mass ratio between DOPA, AMPA and NaMT.
DOPA1 + MLM1 is a 1/1 mass ratio of DOPA and MLM.
DOPA + Tris-HCl* is a DOPA sample crosslinked in water with catalytical amount of Tris-HCl
[0040] Comparison between the theoretical and observed microcombustion data indicates that the combination of melamine (MLM) and DOPA and the combination of DOPA and NaMT act synergistically to prevent combustion, as indicated by higher char and lower heat release. AMPA appears to act synergistically only when combined with DOPA and NaMT, and showed a 80% increase in organic content over the DOPA+NaMT test and only a slightly lower inhibition of combustion. It should be noted that the microcombustion calorimeter cannot capture physical effects on flammability like intumescence. FIGS. 1A and 1B show the residues of DOPA, AMPA and AMPA+DOPA. There is an obvious intumescence effect when DOPA and AMPA are combined together.
[0041] Microcombustion tests were also conducted on coated PUF samples. The foam samples were roughly cubic, measuring 5 mm per side and weighing 4 mg to 5 mg. In this example, foams were first soaked in dopamine, dopamine-AMPA, dopamine-phytic acid or dopamine-GlcN6P in water solutions and squeezed to remove excess liquid. The solutions may also have included proton-exchanged montmorillonite (HMT). The PUF samples were soaked and squeezed 3 times in a solution to promote uptake throughout the sample. The samples were cross-linked at room temperature in a chamber containing concentrated ammonia for 90 minutes, then dried at 90° C. for 2 h. The coating uptake after drying was 10% to 25% by mass. The control foams (no coating) burned completely during the microcombustion test. Most dopamine-AMPA-HMT coated foams and dopamine-GlcN6P-HMT coated foams, inhibited or prevented collapse of the foam structure. The formation of a stable foam-like residue is beneficial in terms of flammability reduction because it can act as a protective thermal insulating layer, capable to protect the underlying unburned foam in real scale burning.
[0042] Cone calorimeter tests were conducted on coated PUF samples. The foam samples measured 10 cm×10 cm×1 in and weighed 11 g to 12 g. In this example, foams were first soaked in dopamine-AMPA, dopamine-phytic acid or dopamine-urea phytate, monobasic in water solutions and squeezed to remove excess liquid. The solutions also included proton-exchanged montmorillonite (HMT). The PUF samples were soaked and squeezed 3 times in a solution to promote uptake throughout the sample. Three replicate samples were prepared from a single solution of a particular formulation. Some samples were cross-linked at room temperature in a chamber containing concentrated ammonia for 90 minutes, then dried at 90° C. for 2 h. Others were dried at 90° C. for 2 h, then cross-linked at room temperature in a chamber containing concentrated ammonia for 90 minutes. The coating uptake after drying was 20% to 25% by mass.
[0000]
TABLE 2
Ignition times, heat release rates, and char as measured by cone calorimetry.
t ign
t PHRR
PHRR
AHRR
THR
ΔH comb
Char
Sample
(s)
(s)
(kW/m 2 )
(kW/m 2 )
(MJ/m 2 )
(MJ/kg)
(%)
Foam
3.8
67.5
435
256
33.1
30.0
3.0
DA-dx
4.0
77.0
345
226
30.9
23.9
13.0
DP-dx
4.3
80.3
382
227
31.4
24.7
13.0
DP-xd
5.3
83.0
431
251
30.3
23.4
16.0
DUP-xd
4.5
83.0
373
205
30.6
23.5
14.9
DA-dx: DOPA/AMPA, dried then cross-linked
DP-dx: DOPA/Phytic acid, dried then cross-linked
DP-xd: DOPA/Phytic acid, cross-linked then dried
DUP-xd: DOPA/Urea phytate, monobasic, cross-linked then dried
[0043] Dopamine based coating all delayed time to ignition and time to peak heat release rate while reducing the heat release rate and heat of combustion. Increased char yields approximately correlate with reductions in the heat of combustion. The most significant effects were on the delay of peak heat release and reduction in heat release rates. There was a slight reduction in total heat release. The presence of amine compounds, regardless of the phosphate source, resulted in the largest reductions in flammability. The order of drying and crosslinking had a significant effect on the cone data.
[0044] When Na-MT is also added to DOPA, a nanostructured material is obtained. In fact, as shown by x-ray analysis in FIG. 2 , DOPA is capable of diffusing between the 1-nanometer-thick layers of Na-MT. The average distance between the clay layers increased from 1.15 nm to 1.38 nm. The same distance of about 1.4 nm (not shown) was observed also when AMPA was added to the formulation. Such nanostructures are capable of improving the mechanical strength of the material and reduce its permeability; all features that make the protective coating more effective.
[0045] The embodiments of this invention shown in the drawings and described above are exemplary of numerous embodiments that may be made within the scope of the appended claims.
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A flame retardant coating composition comprising poly(dopamine) and either tris(hydroxymethyl)aminomethane) or gaseous ammonia, as well as an article comprising a substrate and the flame retardant coating composition, is provided. In various embodiments, the poly(dopamine) is substantially water insoluble. The coating composition can further comprise at least one additional component selected from the group consisting of melamine, an anionic clay, a phosphorus-containing compound, an amine-containing compound, aluminosilicates, silicon oxides, and combinations thereof. Also provided are methods for forming the flame retardant coating composition and methods for increasing flame retardant properties of a substrate.
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CROSS REFERENCE OF RELATED APPLICATION
This is a divisional application of U.S. patent application Ser. No. 09/155 017, filed Sep. 16, 1998, now U.S. Pat. No. 6,161,956, titled “PROCESS AND DEVICE FOR THE SYNCHRONOUS CONVEYING OF FLOWABLE MATERIALS IN MIXING DEVICE” which is a 371 of PCT/EP97/01181 filed Mar. 8, 1997.
FIELD OF THE INVENTION
The invention relates to a process for the synchronous conveying of flowable materials. The invention relates furthermore to a device for implementing such a process. More specifically, the invention relates to a process for the synchronous conveying of flowable materials with conveyor pumps in a mixing device, from which the mixture of these materials can be fed to a consumer, for example a spray-paint pistol, whereby the conveyor pumps are each operated by means of a hydraulic adjusting unit, in which one operating piston is guided in an operating cylinder, and whereby the adjusting units lie in a hydraulic circuit of a drive fluid loading the operating pistons. The invention relates furthermore to a device for implementing such a process.
BACKGROUND OF THE INVENTION
A process of this type and an associated device are already known from the Patent Application EP 0 644 025 A1, in which two dosing conveyor pumps convey the individual materials into one single mixing device in such a manner that a drive member of a first conveyor pump is loaded with a constant flow pressure and the flow pressure of the drive fluid loading a second drive member are each controlled by adjusting commands of a control device such that the through-flow measured values of the conveyor streams fed by the conveyor pumps have a predetermined relationship, which can be superimposed onto the control device as a desired value.
During a relatively slow conveying of the materials such a control indeed assures their homogeneous mixing. It is possible, at relatively high conveying speeds, for inhomogeneities to occur in the conveyed mixed goods, which can cause difficulties during technical use.
Moreover, the operating efficiency of the control depends essentially on the pressure measurements and controls in the circuit of the drive fluid, which demand measuring devices for the occurring pressures. The demand measuring devices can be calibrated and operate reliably over long periods of time. The measured values from these pressure measurements must thereby be connected with measured values for the travel paths covered by the operating pistons, for the determination of which distance sensors are mounted on the operating cylinders, which are controlled by the operating pistons themselves or by back and forth moving structural parts connected to these. The measured values of pressure and travel distance must then in addition be mathematically connected in order to obtain therefrom the actual values for the conveyor streams out of the conveyor pumps and, therefrom the actual mixture ratio of the materials fed to the mixer. Time delays must be expected in particular for mechanical measurement of the pressures. It is therefore not certain that the materials are continuously processed into a homogeneous mixture, which at all times has the desired mixture ratio. Rather local heterogeneities and deviations from the mixture ratio can, at times, not be avoided in the finished mixture.
It is also already known to carry out the conveying of the materials by means of conveyor pumps, each single one of which is driven by a hydraulic adjusting unit, and in which the flow of the drive fluid active in the adjusting unit can each be adapted by a control valve, which is controlled by a proportional governor. Even though high conveying pressures and performances can be easily handled here, the arrangement often cannot accomplish a mixing of homogeneous goods, which mixing is constant in a wide conveying range, because the adjusting units cannot be synchronized with one another in such a manner that the conveying directions correspond always in various adjusting units, especially when a reversal in direction of the operating piston movement takes place at the same time.
Therefore one obvious solution already used is to enable the drive of several adjusting units to be carried out only by one single drive unit so that the conveyor pumps are now operated simultaneously and one indeed achieves a homogeneous distribution of the conveyed materials in the mixed goods. The condition for a satisfactory operation is hereby a fixed and unchangeable mixture ratio. However, if one wants to change the mixture ratio, the conveyor pumps must be changed. In addition, adjustable gearing does not help when the technical parameters are supposed to be maintained very precisely without earlier additional expensive tests being carried out on the system.
Such a gearing is also called a swivel arm, with which at times a kinematic connection between the operating pistons is created, and which can be adjusted in such a manner that the ratio of the operating strokes carried out with the operating pistons can be changed. The maximum operating stroke of one of the adjusting units is mostly left constant and the operating stroke of the second adjusting unit is changed. The system must also be newly adjusted after each change. More difficult yet is that only limited drive and conveying performances can be realized with such lever gearings. The adjustment is connected with a considerable time input.
EP Patent 0 116 879 B1 discloses a process including an associated device, in which, in place of the pressure measured values, the through-flow measured values of the conveyor streams are measured and are superimposed as counting impulses onto a control device, and the conveyor volume of the participating materials are thereby determined in such a manner that in a first mixer, the mixing block, a desired mixture ratio is approached. The finished mixture is partially transported into a second mixer, the mixing pipe, from which it then can be continuously removed by a consumer. Thus at least two mixers are needed in order to create a continuously conveyed mixture.
The basic purpose of the invention is therefore to design a process and an associated device of the type identified in detail in the beginning in such a manner that a continuous mixing of the materials in one single mixing chamber and in one specified mixture ratio to one another occurs, the size of which moves in an interval, which meets all demands. Homogeneous throughout mixed goods are thereby obtained. A simple, robust and inexpensive device is able to be operated with an inexpensive control.
The purpose is attained, according to the invention, by a process wherein the control of the mixture ratios is very much simplified because now merely the operating strokes must be measured in the adjusting units. The ratio is characterized by a constant operating stroke of a first adjusting unit and an operating stroke of the second and each further adjusting unit, which operating stroke can be changed and defines the mixture ratio. Since the movements of the operating pistons occur simultaneously, and merely the flow of the operating fluid is controlled by the second and each further adjusting unit, the speed of the operating pistons change in the following adjusting units. Successful distance sensors are available for length measurement of the operating strokes, which sensors are already being used in such processes.
To carry out the process of the invention, a device can be used having at least two. Two adjusting units which are designed as double-acting hydraulic cylinders and are hydraulically connected with one another in such a manner that the drive fluid conveyed under the influence of the drive motor out of the first adjusting unit drives the second adjusting unit in the same direction. Thus, the first adjusting unit functions hereby as the drive of both a first conveyor pump for a first material and also as the drive of a second adjusting unit and thus of a second conveyor pump associated with same for a further material without the adjusting units having been mechanically connected with one another. The above-described disadvantages of such a connection are avoided here. Also a separate drive for each of the conveyor pumps is not needed in the case of the device of the invention. Its adjusting units are separately hydraulically coupled with one another, and care must merely be taken at the second and eventually each further adjusting unit for a simultaneous course of travel for the other piston strokes with the piston on the first adjusting unit. The state of the art has many possibilities. As long as the drive fluid is not changed, adjustment occurs only once and must be corrected only when through leakages, volume differences occur in the drive fluid.
A hydraulic connection can be created in a simple manner in the adjusting units, which are inventively designed as double-acting hydraulic cylinders, such that the cylinder chambers of the operating cylinders on both sides of the respective operating piston are alternately connected with one another by hydraulic connecting lines, which are best designed as essentially nonblockable. The operating pistons are in this manner at all times loaded synchronously and in the same direction.
The volume of the operating fluid conveyed through the second adjusting unit is influenced such that the connecting lines are connected with one another through a hydraulic control line, and that a controllable blocking device is provided in the control line, whereby the branches of the control line are connected with one another preferably in a hydraulic bridge circuit like a Wheatstone bridge, and the blocking device is arranged in the bridge branch of the bridge circuit. The blocking device can advantageously be controlled by a proportional governor in dependency of the operating signal from the control device. Leakages are compensated for and a buffer is created for differences in amounts during the control when a preferably nonblockable pressure store for excessive drive fluid is provided in the control line.
The return points or reversing points of the back and forth moving operating pistons can be moved into corresponding concruency when the position of the operating piston having an accumulated drive fluid is changed on at least one adjusting unit.
The drive motor is, with respect to its design, basically not dependent on the device of the invention. However, it has been found to be particularly advantageous to operate it by means of compressed air. Thus it is possible that it can be switched in dependency of the pressure difference existing between the connecting lines, for example, by a travel distance valve placed into the pneumatic fluid lines for the drive motor, which in turn can be switched by the pressure difference. The drive motor can, in this manner, only be activated when the hydraulic system is in operation. The direction reversal can be controlled at its return points by contact switches or the like. The use of compressed air as driving energy is particularly advantageous by providing explosion protection when the process of the invention is used for spray painting.
It is advantageous when a drive piston of the drive motor, the operating piston of the first adjusting unit, and a dosing piston of the conveyor pump belonging to the same are rigidly connected with one another, preferably through tight couplings between the respective piston rods.
The control of the drive fluid can occur with a control block of four check valves installed in the control line, which valves are switched such that the drive fluid out of one connecting line is fed at excess pressure against the respective other connecting line through the blocking device into the pressure store or into the respective other connecting line, whereas at underpressure against the respective other connecting line out of the pressure store or out of the output of the blocking device. The control line can for this purpose consist in particular of each branch of the connecting lines, and each one check valve for both flow directions can be provided in each branch, whereby a common supply or discharge line for the blocking valve is connected to the check valves with the same flow direction. The pressure store or reservoir can be connected to the common discharge line by a branch.
Such a simple arrangement assures the control of the second operating drive with very simple means. The control members are successful, reliable structural parts of a simple design with a long life, which furthermore in case of a defect can quickly be exchanged.
It is easily possible that the adjusting unit is flanged to the drive motor in a conventional manner by means of several spacer bolts so that a moved machine part remains visible between the pistons of the drive motor and the adjusting unit. This machine part can be equipped with a motion pickup, which is stationary thereon, and which releases measuring signals to a distance position sensor fixed on the drive motor and/or the adjusting unit. Such an arrangement can also be provided between the adjusting unit and the flanged-on conveyor pump. It is very advantageous when an incrementally operating longitudinal scale rod is thereby used as the distance position sensor. Such primary elements consisting of a motion pickup and a distance position sensor are commercially available in many dimensions and with adjustable measurement lengths.
As a whole it has become possible through the invention that the mixture removed by the consumer at the mixer is not only essentially homogeneous but is also delivered in a constant ratio of the material parts. At the same time, expensive special constructions for the structural and operating elements, which are being used, are thereby avoided and instead structural parts available commercially for a long time are utilized.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be discussed in greater detail hereinafter in connection with one exemplary embodiment and the drawing. The single FIGURE shows thereby a device of the invention in a rather schematic illustration, with which the process of the invention can be advantageously carried out.
DETAILED DESCRIPTION OF THE INVENTION
A device according to the invention includes a pneumatic drive motor 1 , a first hydraulic adjusting unit 2 flanged to the drive motor 1 , a second hydraulic adjusting unit 3 , which is driven from the first adjusting unit 2 , and the associated lines and control devices.
The adjusting units 2 , 3 have the purpose of driving two conveyor pumps 4 for the dosing conveying of one flowable material each into a mixing device 18 , in particular into a static or dynamic mixer of common design, which is schematically shown connected to the conveyor pumps 4 from their outputs 41 a , 42 a through hoses or pipelines.
The adjusting units 2 , 3 each are essentially composed of one operating cylinder 21 , 31 and one operating piston 22 , 32 , whereby piston rods 23 , 33 are provided for the operating pistons 22 , 32 , which piston rods have the purpose of guiding the operating pistons 22 , 32 in the operating cylinders 21 , 31 . Furthermore, the drive of the operating piston 22 is accomplished with the piston rod 23 . It is for this purpose connected with the help of a tight coupling K to a piston rod 12 , which belongs to a drive piston 11 . Another coupling K couples piston rod 12 to a piston rod 15 for a dosing piston 16 . The drive piston 11 is part of the pneumatic drive motor 1 , which is designed as a double-acting piston engine. The corresponding compressed-air lines, which end in its piston cylinder 13 , however, are not shown in the drawing. They are not directly part of the invention and are common state of the art in this field. A pneumatic distributing valve can be arranged in one of these lines, which valve enables switching of the drive motor 1 only in dependency of an orderly switching of the hydraulic area.
The adjusting units 2 , 3 are designed as double-acting just like the drive motor 1 . Their respective cylinder chambers Z 2 , Z 3 or Z 2 ′, Z 3 ′ in the operating cylinders 21 , 31 in front of and back of the operating pistons 22 , 32 are hydraulically connected with one another through connecting lines S. A first connecting line 51 connects thereby one cylinder chamber Z 2 of the adjusting unit 2 to a cylinder chamber Z 3 ′ of the adjusting unit 3 and a second connecting line 52 connects the two remaining cylinder chambers Z 2 ′, Z 3 with one another. The stamping pressure exerted by the operating piston 11 exists thereby in the cylinder chambers Z 2 , Z 3 ′ when the drive piston 11 is driven in conveying direction, whereas the other cylinder chambers Z 2 ′, Z 3 have a significantly lower hydraulic pressure, because the operating pistons 22 , 23 carry out merely the pure operation of movement via the drive fluid. The pressure relationships are correspondingly reversed during a counter-stroke of the operating piston 11 .
Branches 61 a , 61 b of a control line 61 are branched off to a control device 6 from the connecting lines 5 . The control device 6 further includes a blocking device 63 , a control block 64 and a pressure store or reservoir 65 . An electronic control device 66 controls the blocking device 63 . The blocking device 63 is moved by a proportional governor 63 a in such a manner that a second conveyor pump 42 , which is flanged to the adjusting unit 3 and is driven by same, feeds a conveyor volume changeable with respect to a first conveyor pump 41 into the mixer. The volume stream, which is moved through the respective connecting lines 5 by the operating piston 22 , is for this purpose divided by the blocking device 63 into a part, which is fed into one of cylinder chambers Z 3 , Z 3 ′ of the second adjusting unit 3 , and does not at all pass the blocking device 63 , and into a part, which is returned through the other connecting line 5 into the adjusting unit 2 and also into one of its cylinder chambers Z 2 , Z 2 ′.
One can in this manner use the first adjusting unit 2 as a guiding device with a constant operating stroke and constant conveyor stream from the flanged-on conveyor pump 41 . The second adjusting unit 3 , as a follow-up device, carries out a variable operating-stroke, which determines the conveyor stream from the second conveyor pump 42 and the respective mixing ratio of the materials fed to the mixer.
The branches 61 a , 61 b of the control line 61 form a hydraulic bridge circuit B like a Wheatstone bridge, into the bridge branch 60 of which is placed the blocking device 63 . The control stream flowing through the bridge branch 60 directs its flow direction in accordance with the conveying direction of the operating piston 11 , whereby in each case the opposite direction is blocked by check valves R. The blocking direction of each of two strands of the control line 61 , which converge at common ends E 1 , E 2 of the bridge branch 60 , is the same.
The pressure store 65 is also connected to the bridge branch 60 , into which store excessive operating fluid is fed, if necessary, which when needed again is discharged from the pressure store 65 .
The regulating distances of the operating pistons 22 , 32 in the adjusting units 2 , 3 are detected by distance position sensors 66 a , 66 b , which are a part of the control device 66 and the measuring signals of which stand ready as actual values in the control device 66 . Each operating piston 22 , 32 itself can serve as the motion pickup. However, it is also possible to use a separate motion pickup fastened to the piston rods 23 , 33 .
The operating signal, which is obtained through a comparison of the measuring signals delivered from the position sensors 66 a , 66 b with a variable desired value adjusted at the control device 66 , is superimposed from the control directly onto the proportional governor 63 a.
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Instead of a discontinuous mixing process for mixing two or more flowable materials for a paint-spraying plant, a continuous mixing and conveying process is provided. Use is made of individual conveyor pumps driven individually by hydraulic adjusting units in the form of double-acting hydraulic cylinders. Control is exerted by an electronic control device controlling a proportional governor at hydraulic connecting lines between the adjusting units to adjust the stroke of pistons of the adjusting units and thus the ratio of the flowable material conveyed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-026654, filed Feb. 2, 2005, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a quantum computer and quantum computation method utilizing coupling of an optical cavity with an atom.
[0004] 2. Description of the Related Art
[0005] L.-M. Duan et al. have proposed a new method for realizing a controlled phase flip gate (see, for example, L.-M. Duan and H. J. Kimble, Phys. Rev. Lett. 92, 127902 (2004)). In this proposal, quantum bits are expressed by polarization of photons. However, in quantum computers, it is preferable to express quantum bits using atomic states that are more stable and easily usable as memories.
[0006] In light of this, Y.-F. Xiao et al. have proposed a controlled phase flip gate in which a change in light beam intensity in a cavity due to strong coupling between the cavity and an atom is utilized like the method of Duan, but the quantum bits are expressed by ground states of the atoms (see, for example, Y.-F. Xiao, X.-M. Lin., J. Gao, Y. Yang, Z.-F. Han, and C.-C. Guo, Phys. Rev. A 70, 042314 (2004); and Y.-F. Xiao, Z.-F. Han, Y. Yang, and C.-C. Guo, Phys. Lett. A 330, 137 (2004)).
[0007] Xiao et al. state in these papers that the methods are scalable since they exhibit a low error rate.
[0008] However, Xiao et al. suggest nothing about the specific structure of a quantum computer containing three or more quantum bits. Moreover, even if a researcher in this technical field has mastered the methods proposed by Xiao et al., it is still not obvious for them to contrive any specific structure of the quantum computer containing three or more quantum bits.
BRIEF SUMMARY OF THE INVENTION
[0009] In accordance with a first aspect of the invention, there is provided a quantum computer comprising:
[0010] a plurality of optical systems arranged in series each of the plurality of optical systems comprising:
a first half-wave plate which receives a light beam; a first polarizing beam splitter which receives a light beam passing through the first half-wave plate; a first switching mirror which reflects or transmits a first light beam transmitted by the first polarizing beam splitter; a first photodetector which detects the first light beam transmitted by the first switching mirror; a first polarization rotator which receives the first light beam reflected by the first switching mirror; an optical cavity which receives the first light beam passing through the first polarization rotator and contains an atom; a second switching mirror which reflects or transmits a second light beam reflected by the first polarizing beam splitter; a second photodetector which detects the second light beam transmitted by the second switching mirror; a second polarization rotator which receives the second light beam reflected by the second switching mirror; and a high reflection mirror which receives the second light beam passing through the second polarization rotator and reflects the received light beam in a direction opposite to an incident direction of the received light beam, the first polarization beam splitter outputting a third light beam received from the first switching mirror or the second switching mirror to adjacent one of the optical systems;
[0021] a plurality of third switching mirrors each provided between adjacent two optical systems, each of the third switching mirrors reflecting or transmitting a light beam output from one of the two optical systems;
[0022] a plurality of light sources each providing the light beam to the corresponding optical system; and
[0023] a measurement system which measures polarization of an incoming light beam, the measurement system comprising:
a second half-wave plate which receives the incoming light beam output from the last-stage optical system, the last-stage optical system arranged at an down end of the plurality of optical systems: a second polarizing beam splitter which receives the incoming light beam passing through the second half-wave plate; and a pair of third and fourth photodetectors, the third photodetector detecting the incoming light beam reflected by the second polarizing beam splitter, the fourth photodetector detecting the incoming light beam transmitted by the second polarizing beam splitter.
[0027] In accordance with a second aspect of the invention, there is provided a quantum computer comprising:
[0028] a plurality of optical systems arranged in series each of the plurality of optical systems comprising:
a first half-wave plate which receives the light beam; a first polarizing beam splitter which receives a light beam passing through the first half-wave plate; a first switching mirror which reflects or transmits a first light beam transmitted by the first polarizing beam splitter; a first photodetector which detects the first light beam transmitted by the first switching mirror; a first polarization rotator which receives the first light beam reflected by the first switching mirror; an optical cavity which receives the first light beam passing through the first polarization rotator and contains an atom; a second switching mirror which reflects or transmits a second light beam reflected by the first polarizing beam splitter; a second photodetector which detects the second light beam transmitted by the second switching mirror; a second polarization rotator which receives the second light beam reflected by the second switching mirror; and a high reflection mirror which receives the second light beam passing through the second polarization rotator and reflects the received light beam in a direction opposite to an incident direction of the received light beam, the first polarization beam splitter outputting a third light beam received from the first switching mirror or the second switching mirror to adjacent one of the optical systems; and
[0039] a plurality of third switching mirrors each provided between adjacent two optical systems, each of the third switching mirrors reflecting or transmitting a light beam output from one of the two optical systems.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0040] FIG. 1 is a view illustrating an optical system for performing a CZ gate operation on atomic and photonic quantum bits;
[0041] FIG. 2 is a view illustrating the energy level structure of an atom having three energy levels;
[0042] FIG. 3 is a view illustrating a quantum circuit equivalent to a CZ gate acting on quantum bit 1 and quantum bit 2 , which uses additional quantum bit 3 ;
[0043] FIG. 4 is a view illustrating an optical system for performing a CZ gate operation on two atomic quantum bits;
[0044] FIG. 5 is a view illustrating an optical system giving extensibility to a quantum computer according to an embodiment;
[0045] FIG. 6 is a view illustrating the quantum computer of the embodiment;
[0046] FIG. 7 is a view useful in explaining how to realize a CZ gate by the quantum computer of FIG. 6 ;
[0047] FIG. 8 is a view illustrating how to realize a switching mirror using a ring cavity;
[0048] FIG. 9 is a view illustrating how to realize a switching mirror using an etalon;
[0049] FIG. 10 is a view useful in explaining a method for reading a quantum bit in the quantum computer of FIG. 6 ;
[0050] FIG. 11 is a view illustrating a quantum-circuit expression for FIG. 10 ;
[0051] FIG. 12 is a view illustrating the energy level structure of an atom having four energy levels;
[0052] FIG. 13 is a view illustrating a quantum computer for performing a CZ gate operation on atomic and photonic quantum bits, according to example 1;
[0053] FIG. 14 is a view illustrating the energy level of a Pr +3 ion doped in Y 2 SiO 5 crystal;
[0054] FIG. 15 is a view illustrating light beam frequencies for performing the Raman transition;
[0055] FIG. 16 is a view illustrating a quantum computer, according to example 2, for performing a CZ gate operation on atomic and photonic quantum bits, utilizing a single-photon pulse;
[0056] FIG. 17 is a view illustrating a quantum computer for performing a CZ gate operation on two atomic quantum bits, according to example 3;
[0057] FIG. 18 is a view illustrating a quantum computer, according to example 4, in which etalons are used as the switching mirrors; and
[0058] FIG. 19 is a view illustrating a quantum computer, according to example 5, for performing a CZ gate operation on quantum bits corresponding to two atoms contained in cavities that are not adjacent to each other.
DETAILED DESCRIPTION OF THE INVENTION
[0059] The embodiments of the present invention has been developed in light of the above problems, and aims to provide a quantum computer and quantum computation method that are extensible in the number of quantum bits.
[0060] Quantum computers and methods according to embodiments of the invention will be described in detail, referring to the accompanying drawings.
[0061] Firstly, an explanation will be given of fundamental matters related to the quantum computers and methods of the embodiments.
[0062] If an atom is contained in an optical cavity and is strongly coupled with the cavity, when a light beam having a resonant frequency of the cavity enters the cavity, the intensity of the intracavity light is quite different from that in the case where such an atom does not exist.
[0063] In general, the strong coupling between a cavity and an atom means the coupling constant g is greater than the damping rate κ of the cavity and the relaxation rate γ of the atom (g>κ, γ).
[0064] Explaining this phenomenon in more detail, an incident light cannot enter the cavity when an atom strongly coupled with the cavity exists in the cavity, while the incident light enters the cavity when such an atom does not exist. The intensity of the incident light beam is limited. If the intensity is too high, the intensity change of the intracavity light is not caused by such an atom. Therefore, the intensity of the incident light beam must be set to as a low level as enables the intensity change to be caused. As described later, by utilizing this phenomenon, a controlled phase flip gate acting on a quantum bit expressed by polarization of a photon and a quantum bit expressed by the ground states of an atom can be realized.
[0065] The controlled phase flip gate (also called a CZ gate) is a universal gate, and is used together with one-quantum-bit gates to perform an arbitrary quantum computation. The CZ gate performs the following transformation.
α 00 |0>|0>+α 01 |0>|1>+α 10 |1>0>+α 11 |1>1>→α 00 |0>|0>+α 01 |0>|1>+α 10 |1>|0>−α 11 |1>|1> (1)
[0066] The CZ gate employed in this description is similar in principle to that proposed by the above-mentioned Xiao et al., but different therefrom in structure.
[0067] The CZ gate employed in the embodiments is substantially the CZ gate proposed by the above-mentioned Duan et al., which is performed on a quantum bit expressed by polarization of a photon and a quantum bit expressed by the ground states of an atom. Referring first to FIG. 1 , an optical system for realizing this CZ gate will be described.
[0068] As shown in FIG. 1 , this optical system comprises a polarizing beam splitter (PBS) 101 , two polarization rotators (in FIG. 1 , quarter-wave plates (QWPs) 201 and 202 ), a high reflection mirror 301 and a one-sided optical cavity 401 containing an atom with three energy levels such as shown in FIG. 2 .
[0069] The PBS 101 reflects a vertically polarized light beam, and passes therethrough a horizontally polarized light beam.
[0070] The QWPs 201 and 202 invert vertical and horizontal polarizations of the light passing through the QWPs twice. The PBS 101 and QWPs 201 and 202 , which have the above properties, are used to separate an incident light beam and a reflected light beam from each other. In this case, a circularly polarized light beam enters the one-sided optical cavity 401 . If a Faraday rotator and a half-wave plate (HWP) are used instead of the QWPs, an incident light beam and a reflected light beam can be separated from each other, and a linearly polarized light beam enters the one-sided optical cavity 401 . In the embodiment, the QWPs are used.
[0071] The high reflection mirror 301 reflects a light beam in a direction opposite to the direction of the incident.
[0072] The frequency of an incident photon is set equal to the resonant frequency of the cavity. The one-sided optical cavity 401 is, for example, a Fabry-Perot cavity composed of a partially transmitting mirror and a high reflection mirror.
[0073] Referring then to FIG. 2 , the energy levels of the atom contained in the one-sided optical cavity 401 will be described. FIG. 2 is a view illustrating the energy level of the three-level atom. As shown in FIG. 2 , only the atomic transition between |1> and |2> is coupled with an incident light beam (cavity mode).
[0074] In the embodiment, the stable ground states |0> and |1> are used to express quantum bits. The transition between |1> and |2> is strongly coupled with an incident light beam (cavity mode). The expression that the transition between |1> and |2> is strongly coupled with an incident light beam (cavity mode) means that the following three conditions are satisfied: i) a coupling constant between the cavity mode and the |1>−|2> transition is greater than the decay rates of both the cavity and the atom; ii) the transition frequency corresponding to the |1>−|2>transition is equal to the frequency (i.e., equal to the resonant frequency of the cavity) of the incident light beam; iii) owing to a rule of selection, the |11>−|2> transition is coupled with the circularly polarized light beam of the incident light beam, and is not coupled with a light whose polarization is opposite to that of the light mentioned above.
[0075] On the other hand, the |0>−|2> transition does not interact with the incident light beam (cavity mode) because of a large detuning. For simplicity, the incident light beam is assumed to be a single-photon pulse. In the embodiment, a coherent light beam may also be used as the incident light beam. In this case, if the emission of a light beam is stopped when a single-photon is detected, the same result as in the case of using a single-photon pulse can be acquired. Assume here that the coherent light beam is so weak that the intensity change of the intracavity light depending on the existence of the atom strongly coupled with the cavity can be observed.
[0076] Assume that the initial state is given by
|ψ 0 >=α 00 |0>| V>+α 01 |0>| H>+α 10 |1> V>+α 11 |1>| H>, (2)
where the first ket vectors indicate the states of the atom, and the second ket vectors indicate the polarized states of the incident photon. V and H represent vertical polarization (hereinafter referred to as “V-polarization”) and horizontal polarization (hereinafter referred to as “H-polarization”), respectively. Further, assume that V and H correspond to bit “0” and bit “1”, respectively.
[0077] Referring again to FIG. 1 , the V-polarized photon is reflected by the PBS 101 and guided to the high reflection mirror 301 . The photon is then reflected by the high reflection mirror 301 and returned to the PBS 101 . The returned photon is an H-polarized one since it has passed through the QWP 202 twice. Therefore, at this time, it passes through the PBS 101 .
[0078] The H-polarized photon passing through the PBS 101 is guided to the one-sided optical cavity 401 . If the atomic state in the cavity 401 is |0>, the photon enters the cavity 401 and then reflects therefrom, since the cavity 401 is equivalent to a vacuum cavity in this case. In contrast, if the atomic state in the cavity 401 is |1>, the photon reflects therefrom without entering it.
[0079] As found from a simple calculation based on classical optics, the phase of a photon which enters the cavity and reflects from it differs by 180 degrees from that of a photon which reflects from the cavity without entering it. In light of this, the phase flip which occur only when the polarization of a light beam is H-polarization and the atomic state is |1> can be realized. This is equivalent to the realization of a CZ gate in which the ground states |0> and |1> of an atom are used as a control bit, and the polarized states |V> and |H> of a photon are used as a target bit. This CZ gate performs a transformation given by
|ψ 0 >=α 00 |0>| V>+α 01 |0>| H>+α 10 |1>| V>+α 11 |1>| H>→|ψ 1 >=α 00 |0>| H>+α 01 |0>| V>+α 10 |1>| H>−α 11 |1>| V> (3)
[0080] In the above expression, the replacement of |V> and |H> is caused by the QWPs 201 and 202 .
[0081] As described above, a CZ gate acting on atomic and photonic quantum bits is realized simply by applying the photon to a cavity strongly coupled with the atom, apart from the replacement of the V and H polarizations.
[0082] Referring then to FIG. 3 , a description will be given of the fact that a CZ gate between two atoms can be realized using the CZ gate between the atom and the photon. FIG. 3 is a view illustrating a quantum circuit equivalent to a CZ gate acting on quantum bit 1 and quantum bit 2 , which uses additional quantum bit 3 .
[0083] In FIG. 3 , M indicates bit reading, and ZM indicates that if the result of M is 0, nothing is performed, whereas if the result of M is 1, a phase flip gate (hereinafter referred to as “a Z gate”) operation is performed. The Z gate operation is defined by
|0>→|0>, |1>→−|1>(4)
[0084] Further, H in FIG. 3 represents an Hadamard gate (hereinafter referred to “an H gate”), which is defined by
| 0 〉 -> | 0 〉 + | 1 〉 2 , | 1 〉 -> | 0 〉 - | 1 〉 2 ( 5 )
[0085] The H gate can be realized using an HWP in the case of polarization of a photon.
[0086] The quantum circuit shown in FIG. 3 is equivalent to a CZ gate acting on quantum bits 1 and 2 . Explaining in more detail, the CZ gate acting on quantum bits 1 and 2 can be realized by an H gate acting on additional quantum bit 3 , CZ gates acting on quantum bits 1 and 3 and on quantum bits 2 and 3 , measurement of quantum bit 3 , and a Z gate operation acting on quantum bit 1 which is performed or not performed depending on the measurement result. This will now be described briefly. Assume that the initial state is given by
|ψ 0 >=(α 00 ″00>+α 01 |01>+α 10 |10>+α 11 |11>)|0> (6)
[0087] In this case, the state of the quantum circuit immediately before bit reading M is given by
| ψ 1 〉 =
( α 00 | 00 〉 + α 01 | 01 〉 + α 10 | 10 〉 - α 11 | 11 〉 ) | 0 〉 + ( α 00 | 00 〉 + α 01 | 01 〉 - α 10 | 10 〉 + α 11 | 11 〉 ) | 1 〉 2 ( 7 )
[0088] (7)
[0089] In accordance with the result of bit reading M performed thereafter, quantum bits 1 and 2 are varied in the following manners:
|ψ 2 >=α 00 |00>+α 01 |01>+α 10 |10>−α 11 |11>
|ψ 2 >=α 00 |00>+α 01 |01>−α 10 |10>=α 11 |11> (8)
[0090] Accordingly, if nothing is done when quantum bit 3 is 0, and a Z gate operation is performed when quantum bit 3 is 1, the state becomes
|ψ 3 >=α 00 |00>+α 01 |01>+α 10 |10>−α 11 |11> (9)
[0091] Thus, it is found that a CZ gate acting on quantum bits 1 and 2 can be realized by the quantum circuit shown in FIG. 3 .
[0092] Here, a Z gate acting on the atomic quantum bit can be realized by the Raman transition. The Raman transition indicates a phenomenon in which Rabi oscillation between |0> and |1> is caused by a light beam of two frequencies the difference of which is equal to the |0>−|1> transition frequency, and which do not equal the |0>−|2> and |1>−|2> transition frequencies.
[0093] To perform a CZ gate operation on two atomic quantum bits, in the quantum circuit of FIG. 3 , quantum bits 1 and 2 are expressed by the respective atomic states, and quantum bit 3 is expressed by polarization of the photon. Further, CZ gates acting on quantum bits 1 and 3 and on quantum bits 2 and 3 are performed using the scheme shown in FIG. 1 .
[0094] Referring to FIG. 4 , it will be described how the quantum circuit of FIG. 3 is realized using the scheme shown in FIG. 1 . FIG. 4 shows an optical system for performing a CZ gate operation on two atomic quantum bits.
[0095] As shown in FIG. 4 , the optical system comprises PBSs 101 , 102 and 103 , QWPs 201 , 202 , 203 and 204 , high reflection mirrors 301 , 302 , 303 and 304 , one-sided optical cavities 401 and 402 , HWPs 501 , 502 and 503 , and photodetectors 601 and 602 .
[0096] The HWPs 501 to 503 provide H gates acting on photonic quantum bits expressed by polarization as mentioned above.
[0097] The photodetectors 601 and 602 detect whether photons come or not.
[0098] The other device components are similar to those shown in FIG. 1 .
[0099] Quantum bits 1 , 2 and 3 shown in FIG. 3 are expressed by the ground states of an atom in the one-sided optical cavity 401 ( FIG. 4 ), by those of an atom in the one-sided optical cavity 402 ( FIG. 4 ), and by the polarization of a photon, respectively. As mentioned above, |0> and |1> of the photonic quantum bit correspond to V polarization and H polarization, respectively.
[0100] In the CZ gate shown in FIG. 1 , polarization replacement occurs as indicated in the expression (3). In light of the replacement, to realize the quantum circuit of FIG. 3 by the optical system shown in FIG. 4 , it is sufficient if the HWPs 502 and 503 perform a gate operation (hereinafter referred to “the H′ gate operation”) given by the following expression, which differs only in sign from the H gate operation given by the expression (5).
| 0 〉 -> | 0 〉 - | 1 〉 2 , | 1 〉 -> | 0 〉 + | 1 〉 2 ( 10 )
[0101] The operation of the H′ gate is equivalent to that of the H gate after a NOT gate.
[0102] Further, if the HWP 501 also performs the H′ gate operation, an H-polarized light beam is used as an incident light beam instead of a V-polarized light beam. Since it is simple if all the HWPs have the same function, it is hereinafter assumed that all the HWPs are used to perform the H′ gate operation, and an H-polarized light beam is used as an incident light beam.
[0103] From the above, it is found that the optical system of FIG. 4 can realize a CZ gate on two atomic quantum bits using a photon. However, it is not obvious how to construct the optical system in order to increase the number of quantum bits. The embodiment of the invention proposes a method that enables a quantum computer using the CZ gate of FIG. 4 to employ as many quantum bits as possible in principle. This method will now be described.
[0104] The first two of the three PBSs shown in FIG. 4 , i.e., the PBSs 101 and 102 , are used to perform CZ gates on the atomic and photonic quantum bits, while the last PBS 103 is used to measure polarization of a photon. To make the quantum computer extensible, these two functions are made to be executed by a single PBS. As described later, to this end, it is sufficient to use a special mirror (hereinafter referred to as “the switching mirror) which can switch its reflectivity between low (for high transmission) and high (for high reflection).
[0105] Referring to FIG. 5 , an optical system for imparting extensibility to a quantum computer will be described. FIG. 5 shows an optical system in which a single polarizing beam splitter functions for both a quantum gate and a polarization measuring unit, by using a switching mirror that can switch its reflectivity between low (for high transmission) and high (for high reflection).
[0106] The optical system of FIG. 5 is acquired by adding, to the optical system of FIG. 1 , an HWP 501 , photodetectors 601 and 602 , and switching mirrors 701 and 702 . When the switching mirror has high reflection, the optical system of FIG. 5 executes a CZ gate operation on atomic and photonic quantum bits after an H′ gate operation on the photonic quantum bit. In contrast, when the switching mirror performs high transmission, the optical system functions as a polarization-measuring unit for measuring polarization of a photon after an H′ gate operation on the photonic quantum bit. If optical systems similar to the above are prepared and connected to each other via switching mirrors, a CZ gate operation can be performed on quantum bits corresponding to atoms included in any adjacent two of the optical systems. Further, when the optical systems are connected using the switching mirrors, a photon can be directly guided from the outside to any one of the optical systems via the corresponding switching mirror.
[0107] Referring to FIG. 6 , a description will be given of how to connect the optical systems. FIG. 6 shows a quantum computer according to the embodiment.
[0108] As shown in FIG. 6 , optical systems, i.e., an optical system 1 , optical system 2 , . . . , optical system N (N indicates the total number of the optical systems) starting from the left, are connected by switching mirrors. The switching mirror k connects the optical system k to the optical system (k+1) (k=1, 2, N−1). The optical system 2 , . . . , optical system N are similar to the optical system shown in FIG. 5 . However, the optical system 1 and the optical system after the optical system N, shown in FIG. 6 , are not necessarily similar to that of FIG. 5 . Since the optical system 1 does not need to measure polarization of a photon, it may not include photodetectors and switching mirrors. Further, since the optical system after the optical system N merely measures polarization, it only includes a PBS, photodetectors, and an HWP for an H′ gate operation.
[0109] When optical systems are connected as shown in FIG. 6 , a CZ gate operation can be performed on quantum bits corresponding to atoms included in any adjacent two of the optical systems. As a result, a quantum computer in which as many quantum bits as possible are employed can be constructed.
[0110] Referring then to FIG. 7 , a description will be given of how to execute a CZ gate operation on quantum bits k and (k+1) in FIG. 6 , where the quantum bit expressed by the ground states of the atom in the optical system k in FIG. 6 is called quantum bit k.
[0111] As shown in FIG. 7 , a single H-polarized photon pulse enters the optical system k through a switching mirror (k−1) 707 set for high transmission. Using the switching mirrors 701 and 702 in the optical system k for high reflection, a CZ gate operation is performed on the quantum bit k and the photonic quantum bit. Using the switching mirror k 708 for high reflection, the photon is guided to the optical system (k+1). Using the switching mirrors 703 and 704 in the optical system (k+1) for high reflection, a CZ gate operation is performed on the quantum bit (k+1) and the photonic quantum bit. Using the switching mirror (k+1) 709 for high reflection, the photon is guided to the optical system (k+1). Using the switching mirrors 705 and 706 in the optical system (k+2) for high reflection, polarization of the photon is measured. In accordance with the measurement result, a Z gate operation is performed on the quantum bit k.
[0112] By the above operation, a CZ gate acting on the quantum bits k and (k+1) is realized. At the same time, a CZ gate acting on the quantum bits m and (m+1) (m<k−2, m>k+2) can be also realized. Thus, the quantum computer of the embodiment can employ as many quantum bit as possible, and can perform two-quantum-bit gate operations in a parallel manner.
[0113] Referring to FIGS. 8 and 9 , implementation of a switching mirror will be described. FIG. 8 shows a case where a ring cavity is used as a switching mirror, while FIG. 9 shows a case where an etalon is used as a switching mirror.
[0114] The ring cavity can adjust the cavity length. As shown in FIG. 8 , the ring cavity comprises input/output mirrors 801 and 802 , high-reflection mirrors 301 and 302 , and cavity length adjuster 901 . The input/output mirrors 801 and 802 have the same transmission factor. The cavity length adjuster 901 adjusts the optical cavity length. The adjuster 901 can be formed of an electrooptic modulator if the adjustment is based on a change in refractive index, or formed of a piezoelectric transducer if the adjustment is based on a physical distance. The electrooptic modulator changes the optical distance by changing the refractive index, which depends on an applied voltage. Since the electrooptic modulator exhibits a quicker response than the piezoelectric transducer, if the cavity length adjuster 901 utilizes the electrooptic modulator, the cavity length can be adjusted quickly.
[0115] In the above structure, if the cavity length adjuster 901 sets the cavity length to a value that causes the cavity not to resonate with an incident light beam, the incident light beam is reflected therefrom, whereas if the adjuster 901 sets the cavity length to a value that causes the cavity to resonate with an incident light beam, the incident light beam is transmitted therethrough. Thus, the ring cavity can be used as a switching mirror.
[0116] The etalon 1701 shown in FIG. 9 transmits or reflects a light beam depending upon the incident angle of the light beam. In other words, the etalon 1701 can be used as a switching mirror by adjusting the incident angle of the light beam. The incident angle is adjusted by, for example, rotating the etalon 1701 about an axis. If a high reflection mirror 301 is prepared as shown in FIG. 9 , the direction of the light beam reflected from the etalon 1701 can be adjusted.
[0117] Referring to FIG. 10 , the method for reading a quantum bit will be described.
[0118] In this case, the quantum bit k is read. Using the switching mirror (k−1) 705 for high transmission, a single H-polarized photon pulse is guided to the optical system k. Using the switching mirrors 701 and 702 in the optical system k for high reflection, a CZ gate operation is performed on the quantum bit k and the photonic quantum bit. Using the switching mirror k 706 for high reflection, the photon is guided to the optical system (k+1). Using the switching mirrors 703 and 704 in the optical system (k+1) for high reflection, polarization of the photon is measured. As a result, reading of the quantum bit k can be realized, as will be described. Thus, the quantum computer of the embodiment can also perform reading of a quantum bit efficiently.
[0119] Referring to the quantum circuit shown in FIG. 11 , the principle of reading the quantum bit k will be described. FIG. 11 is a quantum circuit diagram useful in explaining why the method shown in FIG. 10 enables to read the quantum bit k.
[0120] The quantum circuit of FIG. 11 is a quantum-circuit expression for FIG. 10 . In the quantum circuit of FIG. 11 , the input of the photonic quantum bit is |0>, and is subjected to an H gate operation. This quantum circuit is a circuit for reading the quantum bit k. Further, this reading method can be applied to both the quantum bit k and quantum bit m (m<k−2, m>k+2) at the same time. Thus, in the quantum computer of the embodiment, quantum bit reading can also be performed in a parallel manner.
[0121] Further, in the quantum computer of the embodiment, if four energy levels (including three lower level states |0>, |1> and |3>, and one upper level |2>) are used instead of three energy levels, a CZ gate operation can also be performed on quantum bits corresponding to atoms contained in cavities which are not adjacent to each other. Referring to FIG. 12 , the case of using the four-level atoms will be described.
[0122] To perform a CZ gate operation on quantum bits k and (k+n) (n is an integer not less than 2), |1> of the quantum bits (k+1) to (k+n−1) are shifted to |3>, and the CZ gates are performed on the quantum bits k and (k+n) in a similar manner to that on the quantum bits k and (k+1), with the switching mirrors k to (k+n−1) set for high reflection. This is because the cavities (k+1) to (k+n−1) are equivalent to a vacant cavity, and hence a photon enters the cavity (k+n) in the same state as that in which it enters the optical system (k+1). Thus, a CZ gate operation can also be performed on quantum bits corresponding to atoms contained in cavities that are not adjacent to each other.
[0123] As described above, a special mirror having its reflectivity changeable between low and high, which can be implemented by a ring cavity having an adjustable cavity length or by an etalon having an adjustable incident angle, enables a single polarizing beam splitter to serve for both a CZ gate and a polarization measuring unit. As a result, a controlled phase flip gate can be performed on any two quantum bits with connected optical systems of the same structure.
[0124] As explained above, in the embodiment, atomic stable states are used as quantum bits, and the phenomenon is utilized in which the intensity of a light in an optical cavity varies because of strong coupling of the cavity with the atom when a light beam enters the cavity. As a result, the embodiment of the invention can provide a quantum computer and quantum computation method in which two quantum bit gate operations can be performed in a parallel manner, and the number of quantum bits can be easily increased.
[0125] Examples according to the embodiment of the invention will be described.
EXAMPLE 1
[0126] Referring to FIG. 13 , a description will be given of an example of the CZ gate on atomic and photonic quantum bits shown in FIG. 1 .
[0127] To confirm whether a CZ gate therebetween is realized or not, bit reading previously described with reference to FIG. 10 is performed. Explaining in more detail, first an atom is preset in a certain known state, then the process shown in FIG. 10 is performed on the atom to measure the state of the atom, and finally it is verified that the measured state corresponds to the preset certain state. When the CZ gate and the bit reading have succeeded, a V-polarized light beam is observed if the preset certain state of the atom is |0>. In contrast, if the preset certain state of the atom is 1>, an H-polarized light beam has to be observed. Accordingly, this example can also be regarded as an example of the reading method.
[0128] In example 1, Pr 3+ ions contained in Y 2 SiO 5 crystal are used as atoms having such three levels as shown in FIG. 2 . The Pr 3+ ions have the energy level structure shown in FIG. 14 . Further, the Pr 3+ ions have the property that they absorb only a linearly polarized light beam. In light of this, in example 1, a Faraday rotator 1501 and HWP 502 are provided, instead of a QWP, in front of an optical cavity 1301 so that a linearly polarized light beam enters the cavity 1301 . The optical cavity 1301 is formed by mirror-polishing the surface of the crystal. The orientation of the crystal is set so that maximum absorption of a V-polarized light beam can be realized. Accordingly, the HWP 502 in front of the optical cavity 1301 is adjusted to apply a V-polarized light beam to the cavity 1301 .
[0129] In this example, the cavity length is 10 mm, the waist radius of the cavity mode is 5 μm, and the transmittance of the input mirror is 10 −6 . In this case, the coupling constant g between the cavity mode and the atom at the waist is 30 kHz, and the damping rate κ of a photon in the cavity mode is 4 kHz. Further, the relaxation rate γ of the exited state of the ion is about 6 kHz. Since in this case, the condition g>κ, γ is satisfied, the coupling of the cavity with the atom in this example is strong.
[0130] The optical cavity 1301 is placed in a cryostat 1401 and kept at 1.4 K by liquid helium therein. A ring dye laser 1101 having a stabilized frequency is used as a light source. The output of the ring dye laser 1101 is an H-polarized light beam. An HWP 504 is provided for converting the output of the laser 1101 into a V-polarized light beam. Acoustooptic modulators 1201 to 1204 perform frequency adjustment.
[0131] In example 1, firstly, an initial state in which only one ion is related to a gate operation is prepared. To this end, firstly, a light beam that resonates with the optical cavity 1301 is applied thereto from the input mirror (i.e., from the left of the optical cavity 1301 in FIG. 13 ) for a while (for about 1 second). As a result, the ions contained in the cavity mode and having an energy level coupled with the cavity mode are made to be in the states which are not coupled with the mode.
[0132] Subsequently, a light beam, whose direction is vertical to the cavity mode, of a frequency higher by 17.30 MHz than the resonant frequency of the cavity is applied to the waist. As a result, the ions positioned near the waist can be returned to the energy level that is coupled with the cavity mode. After that, a light beam is guided to the high-reflection mirror of the cavity 1301 (i.e., from the right of the optical cavity 1301 in FIG. 13 ). While scanning the frequency of the light beam, the intensity of a light beam output through the input mirror is measured. As a result of the measurement, peaks away from each other by 9.5 kHz were observed. This result indicates that one ion is coupled with the cavity mode since the coupling constant g is 30 kHz (9.5=2×30/2π). Thus, the state in which only one ion related to the gate operation exists in the cavity mode can be prepared. Moreover, the state of the ion is |1> in FIG. 14 , which means that the ion is prepared in a known initial state.
[0133] After thus preparing one ion of |1>, a weak H-polarized coherent light beam with an intensity 1 fW (hereinafter, a “weak coherent light beam” indicates a coherent light beam having an intensity of 1 fW) was applied to the cavity via the HWP 501 , and a light beam reflected therefrom was measured by photodetectors 601 and 602 , with the result that a V-polarized photon was acquired. Further, after preparing one ion of |1>, two light beams having two frequencies as shown in FIG. 15 was applied to the ion so that the ion was shifted to |0> by the Raman transition, and the same experiment as the above was performed. As a result, a V-polarized photon was observed. These results indicate that a CZ gate operation on atomic and photonic quantum bits succeeded.
EXAMPLE 2
[0134] In example 2, a single-photon pulse is guided into a cavity, unlike example 1. In example 1, a weak coherent light beam is guided to the cavity. Referring to FIG. 16 , a description will be given of a quantum computer, according to example 2, in which a CZ gate operation is performed on an atom and a photon using a single-photon pulse.
[0135] The right side system of FIG. 16 (i.e., the optical systems located rightward with respect to the PBS 101 , acoustooptic modulator 1204 and beam splitter 1008 ) are similar to those employed in example 1 of FIG. 13 except that the incident light beam is a single-photon pulse. The left side system of FIG. 16 (including the PBS 101 , acoustooptic modulator 1204 and beam splitter 1008 ) are used to generate a single-photon pulse. An optical cavity 1301 included in the left side system is similar to an optical cavity 1302 for a CZ gate.
[0136] A method for generating a single-photon pulse using the left side system will be described. Firstly, a state in which only one ion is in |0> is prepared in the left cavity 1301 by the same method as employed in example 1. Subsequently, a light beam of a frequency higher by 17.30 MHz than the resonant frequency of the optical cavity 1301 is gradually applied to the ion, thereby shifting the state of the ion (atom) to 1> and generating a single photon in the cavity mode via adiabatic passage based on the principle of quantum mechanics. After a while, a single photon in the cavity mode is ejected from the right hand mirror of the optical cavity 1301 . The ejected photon, which is V-polarized, is converted into an H-polarized photon by the HWP 501 and the Faraday rotator 1501 . The H-polarized photon is guided to the right side optical system through the PBS 101 . Thus, a CZ gate operation can be realized using a single-photon pulse.
[0137] Also in example 2, it was found as in example 1 that when the state of the atom in the right hand optical cavity 1301 was initially set to |0>, a V-polarized photon was observed, while when the state of the atom was initially set to |1>, an H-polarized photon was observed. From these results, it is verified that a CZ gate operation between the atom and the photon succeeded.
EXAMPLE 3
[0138] Referring to FIG. 17 , a description will be given of example 3 related to a CZ gate between two atoms.
[0139] Since it is necessary to guide a light beam to a cavity 1302 to lastly read the state of an atom in the cavity 1302 , an optical system including a cavity 1301 is coupled with an optical system including the cavity 1302 via a ring cavity. As shown in FIG. 17 , the ring cavity comprises high reflection mirrors 305 and 306 , input mirrors 801 and 802 , and cavity length adjuster 901 .
[0140] Further, the quantum computer shown in FIG. 17 is fundamentally similar in structure to the CZ gate with extensibility shown in FIG. 7 , therefore example 3 can also be regarded as an example of the CZ gate with extensibility.
[0141] In example 3, to confirm whether a CZ gate operation between two atoms has succeeded, the fact is noticed that a control NOT gate (CNOT) operation can be performed by three gate operations−(an H gate operation on a target bit)→a CZ gate operation→(an H gate operation on a target bit)−. Resulting from the CNOT gate operation,
|0>|0>, |0>|1>, |1>|0>, |1>|1> are respectively changed to
|0>|0>, |0>|1>, |0>|1>, |1>|0>
[0142] By conforming whether these changes have occurred or not, it is confirmed whether the CZ gate operation between two atoms has succeeded.
[0143] Firstly, one ion in each cavity mode is prepared in |1> by the same method as employed in example 1. Subsequently, two light beams having two frequencies as shown in FIG. 15 is applied to the ion in the cavity 1302 , and then an H gate operation is performed by the Raman transition. After that, a weak coherent light beam is applied to the HWP 501 . Cavity length adjusters 901 , 902 and 903 are all adjusted to cause all ring cavities to serve as high reflection mirrors. Polarization of a light beam is measured by photodetectors 603 and 604 . If polarization of a light beam is V-polarization, a control unit 1601 performs nothing, whereas if polarization of a light beam is H-polarization, the control unit 1601 performs a Z gate operation on the ion in the cavity 1301 . Lastly, an H gate operation is performed on the ion in the cavity 1302 by the Raman transition.
[0144] If the CZ gate operation between two atoms has succeeded, the state of the ion in the cavity 1301 has to be kept at |1>, and the state of the ion in the cavity 1302 has to be shifted to |0>. To confirm this, the states of the ions in the cavities 1301 and 1302 are checked in this order.
[0145] To check the state of the ion in the cavity 1301 , the cavity length adjuster 901 is adjusted to cause the ring cavity including it to serve as a high reflection mirror, and the cavity length adjusters 902 and 903 are adjusted to cause the ring cavities including them to serve as high transmission mirrors. After that, a weak coherent light beam is guided to the cavity 1301 through the HWP 501 , and polarization of the light beam is measured by the photodetectors 601 and 602 .
[0146] To check the state of the ion in the cavity 1302 , the cavity length adjuster 901 is adjusted to cause the ring cavity including it to serve as a high transmission mirror, and the cavity length adjusters 902 and 903 are adjusted to cause the ring cavities including them to serve as high reflection mirrors. After that, a weak coherent light beam is guided from the input mirror 801 to the cavity 1302 through the HWP 503 , and polarization of the light beam is measured by the photodetectors 603 and 604 .
[0147] As a result of the measurement, an H-polarized light beam was observed in the case of the ion in the cavity 1301 , and a V-polarized light beam was observed in the case of the ion in the cavity 1302 . From this, it was confirmed that the states of the ions in the cavities 13 . 01 and 1302 were |1> and |0>, respectively.
[0148] Similarly, if the initial states of the ions are |1> and |0>, 0> and |1>, and |0> and |0>, they have to be changed, after the above operation is performed thereon, to |1> and |1>, |0> and |1>, and |0> and |0>, respectively.
[0149] It was confirmed that these changes occurred. The results of the measurements indicate that CZ gate operations were realized between the two atoms (ions).
EXAMPLE 4
[0150] Referring then to FIG. 18 , a description will be given of example 4 in which an etalon is used as a switching mirror. Example 4 differs from example 3 shown in FIG. 17 only in that in the former, etalons with a finesse of about 100 is used instead of the ring cavities. The other structures are similar to those of example 3.
[0151] In example 4, an incident light beam enters each etalon at an incident angle of about 5 degrees. After CZ gate operations were performed on atoms as in example 3, correct results were acquired.
EXAMPLE 5
[0152] Referring to FIG. 19 , a description will be given of example 5 in which a CZ gate operation is performed on quantum bits corresponding to atoms contained in cavities that are not adjacent to each other as shown in FIG. 12 .
[0153] In example 5, a Pr 3+ ion is used as an ion in each cavity as in example 1. Since the Pr 3+ ion has three ground states as shown in FIG. 14 , the ground state other than |0> and |1>, i.e., |3>, is utilized.
[0154] Firstly, the state of an ion in a cavity 1302 in FIG. 19 was set to |3>. Cavity length adjusters 901 to 906 were all adjusted to cause all ring cavities to serve as high reflection mirrors. The states of the ions in cavities 1301 and 1303 were both set to |1>. Next, a CNOT gate operation was performed on the ions in the cavities 1301 and 1303 in the same manner as in example 3.
[0155] Thereafter, the cavity length adjusters 902 and 903 were adjusted so that the corresponding ring cavities serve as high transmission mirrors, whereby a weak coherent light beam is guided to an HWP 501 , and the state of the ion in the cavity 1301 was read by photodetectors 601 and 602 . Subsequently, the cavity length adjuster 906 was adjusted so that the corresponding ring served as a high transmission mirror, and the cavity length adjusters 904 and 905 were adjusted so that the corresponding ring cavities served as high reflection mirrors. After that, a weak coherent light beam is guided to the HWP 505 , and a CZ gate operation on the ion in the cavity 1303 and the photon was performed, whereby the state of the ion in the cavity 1303 was read by photodetectors 605 and 606 . As a result, it was found that the states of the ions in the cavities 1301 and 1303 were |1> and |0>, respectively.
[0156] Similar operations were performed with the initial states of the ions in the cavities 1301 and 1303 set to |0> and |0>, |0> and |1>, and |1> and |0>, respectively. As a result, their states were changed to |0> and |0>, |0> and |1>, and |1> and |1>, respectively. These results indicate that CZ gate operations on the atoms in the cavities 1301 and 1303 that are not adjacent to each other succeeded.
[0157] The quantum computer and quantum computation method of the embodiments are extensible in the number of quantum bits.
[0158] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
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Quantum computer includes optical systems arranged in series each of the plurality of optical systems includes first half-wave plate, first polarizing beam splitter, first switching mirror, first photodetector, first polarization rotator, optical cavity which contains atom, second switching mirror, second photodetector, second polarization rotator, and high reflection mirror, first polarization beam splitter outputting third light beam received from first switching mirror or second switching mirror to adjacent one of optical systems, third switching mirrors each provided between adjacent two optical systems, each of third switching mirrors reflecting or transmitting light beam output from one of two optical systems, light sources each providing light beam to corresponding optical system, and measurement system which measures polarization of incoming light beam.
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FIELD
[0001] The present invention relates to aqueous compositions comprising hydrophilic actives.
BACKGROUND
[0002] For ecological and economic reasons, water is often preferred over organic solvents as a liquid diluent for active compounds. Stable aqueous compositions comprising actives are used in many different technology areas, including the pharmaceutical, agricultural, cosmetic, detergent, and paint industries. For producing stable aqueous compositions comprising lipophilic actives, adjuvants, such as surfactants, are added.
[0003] In contrast, hydrophilic actives typically are simply dissolved in water. However, this method is sometimes problematic. For example, some aqueous compositions containing actives comprise of a large number of ingredients. If hydrophilic actives show lack of stability, there is a tendency of overdosing them to compensate for the stability loss. In other cases, hydrophilic actives dissolved in aqueous compositions may be released to the environment more quickly than desirable. In either scenario (faster release than desired or overdosing), the active may present a variety of problems, such as skin irritation by actives in personal care compositions. Similarly, undesirable interactions, also known as lack of compatibility, between hydrophilic actives and other components may reduce the efficacy of the active.
[0004] Accordingly, it would be desirable to achieve one or more of the following: increased stability of hydrophilic actives in aqueous solutions, reduced impact on substrates to which aqueous compositions comprising the hydrophilic actives are applied, such as skin, controlled release of the hydrophilic actives to the environment, or increased compatibility with other components in aqueous compositions.
SUMMARY
[0005] In one embodiment, the present invention provides compositions, comprising more than 50 weight percent water as the liquid diluent, a hydrophilic active, and a block copolymer comprising at least one block of polymerized ethylene oxide and at least one block of a polymerized alkylene oxide, wherein the alkylene comprises at least 4 carbon atoms.
[0006] The present invention also provides processes for preparing the above aqueous compositions, as well as methods of stabilizing hydrophilic actives and methods of increasing compatibility among hydrophilic actives.
DETAILED DESCRIPTION
[0007] In one embodiment, the present invention provides a composition comprising more than 50 weight percent water as the liquid diluent (i.e., an aqueous composition), a hydrophilic active, and a block copolymer comprising at least one block of polymerized ethylene oxide and at least one block of a polymerized alkylene oxide, wherein the alkylene comprises at least 4 carbon atoms.
[0008] The aqueous composition comprises water as the main liquid diluent, i.e., water amounts to more than 50 percent, preferably at least 70 percent, more preferably at least 90 percent of the total weight of the liquid diluent. In one embodiment, the water is present in a range from about 50 to about 99.5 weight percent, preferably from about 60 to about 98 weight percent, and more preferably from about 65 to about 95 weight percent. The aqueous composition can also comprise one or more organic diluents such as ethyl alcohol, isopropyl alcohol, higher alcohols or propylene glycol, but preferably, water is the only liquid diluent.
[0009] The term “hydrophilic active” as used herein means that the compound is useful in a given aqueous composition for a given end-use, as will be explained, and is soluble at an amount at which the compound is typically used. Preferably, the active's solubility in water is at least 0.1 grams, preferably at least 0.5 grams, more preferably at least 2 grams, most preferably at least 5 grams, in 100 grams of distilled water at 25° C. and 1 atmosphere. It should be noted that unlike the case with a lipophilic active, the block copolymer is not acting as a solubilizer to increase the amount of hydrophilic active which can be incorporated in the aqueous composition. The hydrophilic active is already soluble in the aqueous composition as described above.
[0010] The compositions of the present invention may comprise a wide variety of liquid or solid hydrophilic actives. The hydrophilic actives may be nonionic or ionic. The hydrophilic active may be polymeric, but is preferably monomeric.
[0011] In some embodiments, the compositions of the present invention are personal care compositions. Examples of personal care compositions include hair care, skin care, or mouth care compositions, for example shampoos, conditioners, bleaching compositions, coloring compositions, lotions for skin care, dentifrices, mouth rinses or whitening agents, the hydrophilic actives are, for example, water-soluble anti-inflammatory agents, antibacterial agents, antifungal agents, antiviral agents, anti-seborrhoeic agents, antiacne agents, keratolytic agents, antihistamines, anesthetics, cicatrizing agents, pigmentation modifiers, tanning accelerators, artificial tanning agents, refreshing agents, anti-aging agents, vascular protectors, insect repellants, deodorants, antidandruff agents, agents for preventing hair loss, cleansing agents, fragrances, sunscreens, antioxidants, free-radical scavengers, extracts from plants or algae or man-made components of extracts from plants or algae, water-soluble proteins, protein hydrolyzates, peptides, alpha-hydroxy acids, emollients, moisturizers, such as the sodium salt of pyroglutamic acid, peeling agents, such as glycolic acid, and vitamins. Specific hydrophilic actives which are known compounds of personal care compositions are for example acids, such as salicylic acid, glycolic acid, citric acid, or hyaluronic acid; salts, such as sodium chloride, caffeine derivatives, moisturizers, such as the sodium salt of pyroglutamic acid, glycerol, glycerol derivatives, skin whitening agents, such as dihydroxyacetone, antioxidants such as Vitamin C or sunscreen agents such as benzophenone-4.
[0012] In some embodiments, the compositions of the present invention are pharmaceutical compositions. Pharmaceutical compositions include those for therapeutic, diagnostic, or preventive use, such as small molecules, peptides, proteins, antibodies, vitamins, herbals, and mineral supplements. Pharmaceutical compositions include veterinary and medical uses for human beings. The hydrophilic actives include water-soluble therapeutic agents, diagnostic agents, vaccines, vitamins, herbals and mineral supplements or known adjuvants in pharmaceutical compositions. Specific hydrophilic actives which can be included in pharmaceutical compositions are for example vitamins, such as vitamin C.
[0013] In some embodiments, the compositions of the present invention are liquid detergent compositions wherein the active is a detergent, fabric softener, soil redeposition agent, or other conventional detergent ingredient.
[0014] In some embodiments, the compositions of the present invention are household products such as air fresheners, wipes, or cleaning solutions.
[0015] In some embodiments, the compositions of the present invention are agricultural compositions, for example, to allow a controlled release of an agriculturally beneficial hydrophilic active to the environment.
[0016] In some embodiments, the compositions of the present invention are pharmaceutical compositions, for example, to protect labile actives.
[0017] In some embodiments, the compositions of the present invention are used as an indicator. For example, a hydrophilic dye or pigment active is encapsulated by the block copolymer, and when the temperature of the composition is raised above the stability temperature of the block copolymer, a color change occurs. Alternatively, the incorporated active could be one half of a red-ox pair or a catalyst, such that the composition remains static until heated above a certain temperature, when the active is released.
[0018] The amount of the hydrophilic active in the aqueous composition can vary in a wide range and mainly depends on the desired end-use of the aqueous composition and can be chosen independently of the block copolymer. The hydrophilic active is included in the aqueous composition at an amount that is not higher than its solubility limit in the absence of the block copolymer.
[0019] The block copolymer comprises at least one block of polymerized ethylene oxide (“EO”) and at least one block of a polymerized alkylene oxide, wherein the alkylene comprises at least 4 carbon atoms, preferably 4 to 10 carbon atoms. Preferred alkylene oxides of at least 4 carbon atoms are 1,2-butylene oxide, 1,2-pentylene oxide, 1,2-hexylene oxide, cyclohexylene oxide, or styrene oxide. The most preferred alkylene oxide of at least 4 carbon atoms is 1,2-butylene oxide, which is designated hereafter as “butylene oxide” or “BO.”
[0020] The block copolymer is preferably produced by anionic polymerization.
[0021] Preferably the block copolymer comprises one or two blocks of polymerized ethylene oxide and one or two blocks of a polymerized alkylene oxide of at least 4 carbon atoms. Tri-block polymers of EO-BO-EO are contemplated, provided that the BO block is less than 6 units long. It is beneficial that the EO blocks be terminated with a hydroxyl unit. Particularly, diblock copolymers are preferred.
[0022] In a preferred embodiment, the block copolymer comprises at least one block of ethylene oxide and at least one block of butylene oxide. Thereof, block copolymers comprising 10 to 12 units of polymerized ethylene oxide and 10 to 12 units of polymerized butylene oxide are particularly preferred.
[0023] The weight average molecular weight of the polymerized ethylene oxide block generally is from about 100 to about 2200, preferably from about 100 to about 970, more preferably from about 200 to about 900, and most preferably from about 500 to about 800.
[0024] The block of a polymerized alkylene oxide comprising at least 4 carbon atoms generally has a weight average molecular weight of from about 300 to about 3600, preferably from about 300 to about 1600, more preferably from about 500 to about 1500, and most preferably from about 700 to about 1300.
[0025] The total weight average molecular weight of the block copolymer is preferably less than 5800, more preferably less than 2400, most preferably less than 2000.
[0026] Block copolymers comprising at least one block of polymerized ethylene oxide and at least one block of a polymerized alkylene oxide comprising at least 4 carbon atoms and methods of producing them are known in the art. For example, U.S. Pat. No. 5,587,143, the entirety of which is incorporated herein by reference, discloses butylene oxide-ethylene oxide block copolymers. Likewise, J. Keith Harris et al., “ Spontaneous Generation of Multilamellar Vescicles from Ethylene Oxide/Butylene Oxide Diblock Copolymers” , Langmuir 2002, 18, 5337-5342, the entirety of which is incorporated herein by reference, discusses the behavior of ethylene oxide/butylene oxide diblock copolymers in aqueous solutions.
[0027] The aqueous composition of the present invention preferably comprises from about 0.1 to about 20 weight percent, more preferably from about 0.5 to about 5 weight percent of the block copolymer, based on the total weight of the composition. The weight ratio between the encapsulated hydrophilic active and the block copolymer is preferably from about 0.1 to about 1000:1, more preferably from about 1 to about 100:1.
[0028] It has been found that the resulting aqueous composition is generally stable over a period of at least 1 week, in most cases even over a period of at least 1 month, and, in the preferred embodiments of the present invention, even over a period of at least 3 months.
[0029] While not wishing to be bound by theory, it is contemplated that the block copolymer is useful for encapsulating the hydrophilic active, thus rendering the encapsulated hydrophilic active more stable. It is believed that unilamellar or multi-lamellar vesicles are formed by the block copolymer. These substantially stable vesicles, composed predominantly, by mass, of the block copolymer, self-assemble in water or aqueous solutions. If the aqueous composition comprises an excess of block copolymer, generally from 30 to 95 percent, then typically from 40 to 50 percent of the amount of the hydrophilic active that is present in the aqueous composition is encapsulated. Encapsulation has one or more of the following advantages: increased stability of the hydrophilic active in the aqueous solution, increased compatibility of the hydrophilic active with other components in the aqueous composition, reduced impact on substrates to which the aqueous composition comprising the hydrophilic active is applied, such as skin, and/or controlled release of the hydrophilic active to the environment.
[0030] The capsules comprising a hydrophilic active encapsulated in the above-described block copolymer generally have a diameter of from about 0.05 to about 50 micrometers. The particle size of the capsules can be influenced by ultrasonic treatment or other known procedures if desirable.
[0031] The present invention contemplates additional components to the compositions. For example, encapsulation efficiency can be further improved by adding additional water-soluble ingredients to the external aqueous phase of the aqueous composition after encapsulation of the hydrophilic active in the block copolymer. For example, it has been found that adding a propylene glycol to the aqueous composition improves the encapsulation efficiency. Adding mineral oil also provides improved stability of vesicles and improved encapsulation efficiency.
[0032] Similarly, depending on the intended use, the composition of the present invention may comprise a variety of other components known in the art.
[0033] In one embodiment, a preferred application of the present invention is the stabilization of water-soluble compounds in aqueous formulations, for example stabilization against oxidation. For example, it has been found that vitamin C can be stabilized in aqueous personal care compositions by encapsulating it in the above-described block copolymer. It has also been found that dihydroxyacetone, a skin whitening agent which is used in personal care compositions, can be stabilized in aqueous compositions by encapsulating it in the above-described block copolymer.
[0034] In another embodiment, the present invention improves the compatibility of two compounds in an aqueous formulation, of which at least one is a hydrophilic active. The compatibility of the two compounds can be improved by encapsulating the hydrophilic active in the above-described block copolymer. For example, CARBOPOL™ polymers are cross-linked polymers of acrylic acid which are commonly used as thickeners for lotions. It is well known that their thickening property will be drastically reduced when a salt, such as sodium-2-pyrrolidone carboxylate, is introduced into the lotion. Sodium-2-pyrrolidone carboxylate is a commonly used moisturizer for hair and skin care products. By encapsulating the sodium-2-pyrrolidone carboxylate in the above-described block copolymer, the viscosity of the lotion can be maintained to a substantial extent, as will be shown below.
[0035] Aqueous compositions of the present invention can be produced in a process which comprises the step of blending a hydrophilic active with an above-mentioned block copolymer in an aqueous diluent. All blending types are contemplated, but gentle agitation is generally sufficient to generate closed structures of the above-mentioned block copolymer which encapsulate a hydrophilic active. The blending temperature can vary over a wide range, including room temperature for convenience.
EXAMPLES
[0036] The following examples are for illustrative purposes only and are not intended to limit the scope of the present invention. All percentages are by weight unless otherwise specified.
Example 1
[0037] Encapsulation of a water soluble compound in solution can be determined by the following protocol. A water-soluble fluorescent dye Eosin Y is dissolved in distilled water to prepare a 0.035 weight percent solution. About 10 g of this solution is added to 0.2 g of a diblock copolymer of about 11 units of polymerized ethylene oxide and about 11 units of polymerized butylene oxide, designated as EO 11 BO 11 . The solution and EO 11 BO 11 block copolymer are agitated.
[0038] Examination by plane-polymerized light can detect the formation of multi-lamellar vesicles, which in this protocol would encapsulate a portion of the dye solution. To remove the residual dye in the aqueous phase, the dispersion is mixed with cationic exchange resin. Reexamination of the sample using plane-polymerized light will confirm that the multi-lamellar vesicles are still intact. Finally the multi-lamellar vesicles are disintegrated using tetrahydrofuran to form a clear solution with a definite pink cast confirming that the now released dye was present in the multi-lamellar vesicles during the exchange resin step.
Example 2
[0039] Encapsulation of a water soluble compound in a lotion can be determined by the following protocol.
[0040] A lotion formulation is provided comprising:
100 ppm of vitamin C encapsulated in 1 weight percent of block copolymer EO 11 BO 11 ; 0.5 weight percent of the emulsifier GLUCAMATE™ SS methyl glucoside derivative (CFTA/INCI designation methyl glucose sesquistearate); 1.5 weight percent of the emulsifier GLUCAMATE™ SSE-20 methyl glucoside derivative (CFTA/INCI designation PEG-20 methyl glucose sesquistearate); 4 weight percent of mineral oil; 0.2 weight percent of the thickening agent Carbomer 940, which is commercially available from Noveon under the trademark CARBOPOL™ 940; 0.3 weight percent of triethanolamine; and the remainder being water.
[0047] Using a cross-polarized microscope, if a Maltese Cross pattern is observed, the formation of vesicles by the block copolymer is indicated.
[0048] Substantially following the above protocol, a Maltese Cross pattern was observed.
Example 3
[0049] Encapsulation of yet another water soluble compound in a solution can be determined by the following protocol. Dihydroxyacetone (also known as DHA) is primarily used as an ingredient in sunless tanning products. Reaction of L-lysine with dihydroxyacetone results in a dark brownish color. This color change is used as an indicator in the protocol.
[0050] An aqueous composition comprising 0.2 weight percent dihydroxyacetone is prepared. 1 weight percent, based on water, of EO 11 BO 11 block copolymer is added and the composition is shaken. The composition is filtered through a MWCO dialysis bag (Spectrum Laboratory, Rancho Dominguez, Calif.) to remove any non-encapsulated dihydroxyacetone by filtration.
[0051] 24 weight percent of L-lysine is added to a first sample of the filtered composition, based on the total weight of the sample. If the dihydroxyacetone is encapsulated in the block copolymer, no appreciable color change to brown will occur.
[0052] 9 weight percent of L-lysine and 11 weight percent of ethanol are added to a second sample of the filtered composition, based on the total weight of the sample. The ethanol has the effect that the EO 11 BO 11 block copolymer vesicles are destroyed. Appearance of a brownish color shows that dihydroxyacetone had been encapsulated in the EO 11 BO 11 block copolymer vesicles and is now released upon destruction of the vesicles.
[0053] Substantially following the above protocol, it was observed that dihydroxyacetone is encapsulated in block copolymers comprising a block of polymerized ethylene oxide and a block of polymerized butylene oxide. 2 hours after addition of L-lysine to the first filtered composition, the composition remained colorless. 2 hours after addition of L-lysine to the second filtered composition, the composition developed a brownish color which shows that dihydroxyacetone had been encapsulated in the EO 11 BO 11 block copolymer vesicles.
Example 4
[0054] Encapsulation efficiency in solution can be determined by the following protocol. Aqueous compositions comprising LOWACENE Red-80 dye encapsulated in EO 11 BO 11 vesicles are prepared by blending water with 50 ppm of Red-80 dye and 1 weight percent of EO 11 BO 11 , based on the weight of water. LOWACENE Red-80 dye is an organic water-soluble salt. Degree of encapsulation can be measured as a function of electro-conductivity in the solution. The electro-conductivity of the LOWACENE Red-80 dye is calibrated to render a quantitative value correlating percent of dye encapsulated and conductivity. When the LOWACENE Red-80 dye is encapsulated in block copolymer vesicles, the conductivity will decrease. From the reduction in conductivity measurement, the encapsulation efficiency of block copolymer vesicles can be calculated.
[0055] Substantially following the above protocol, the following results were obtained and are reported in TABLE 1.
[0000] TABLE 1 Encapsulation Sample Ingredients of composition, in addition to water Efficiency (%) 1 50 ppm LOWACENE Red-80 dye 0 2 50 ppm LOWACENE Red-80 dye and 37 1 weight % of EO 11 BO 11 3 50 ppm LOWACENE Red-80 dye and 70 1 weight % of EO 11 BO 11 followed by 0.5 percent of propylene glycol 4 50 ppm LOWACENE Red-80 dye and 65 1 weight % of EO 11 BO 11 followed by 0.5 percent of mineral oil
For Sample 2, the encapsulation efficiency was 37 percent, i.e., 37 percent of the total amount of LOWACENE Red-80 dye in the aqueous composition was encapsulated. The encapsulation efficiency increased to 70 percent by adding 0.5 percent of propylene glycol to the aqueous composition comprising Red-80 dye encapsulated in EO 11 BO 11 in Sample 3. Similarly, the encapsulation efficiency increased to 65 percent by adding 0.5 percent of mineral oil to the aqueous composition comprising Red-80 dye encapsulated in EO 11 BO 11 .
Example 5
[0056] Oxidation of a water soluble compound in solution can be determined by the following protocol. Three aqueous compositions comprising 100 ppm of L-ascorbic acid (vitamin C) are prepared. To prepare the first composition, 100 ppm of vitamin C is dissolved in water. To prepare the second composition, 1 weight percent of EO 11 BO 11 block copolymer based on the weight of water is agitated in water to form vesicles. After vesicle formation, 100 ppm of vitamin C is added to the composition, thus, the vitamin C is not encapsulated in the EO 11 BO 11 block copolymer. To prepare the third composition, 100 ppm of vitamin C is dissolved in water, 1 weight percent of EO 11 BO 11 block copolymer based on the weight of water is added, and the composition is agitated to form EO 11 BO 11 block copolymer vesicles encapsulating vitamin C. The three compositions are placed into an oven at 50° C. for one month to determine the resistance of the vitamin C against oxidation. If vitamin C is oxidized, dehydroxyascorbic acid is formed which absorbs UV light at 350 nm. Vitamin C itself does not absorb UV light at 350 nm. Based on the degree of UV light absorption, the percentage of oxidized vitamin C can be determined.
[0057] Substantially following the above protocol, the following results were obtained and are reported in TABLE 2.
[0000] TABLE 2 % oxidized Sample Ingredients of composition, in addition to water vitamin C 5 100 ppm vitamin C 65 6 100 ppm vitamin C and 1 wt. % EO 11 BO 11 block 43 copolymer, not encapsulated 7 100 ppm vitamin C encapsulated with 1 wt. % 19 EO 11 BO 11 block copolymer
The percentages of oxidized vitamin C, based on the total weight of vitamin C, for each of the three compositions show that encapsulated vitamin C, designated Sample 7, experienced significantly less oxidation than the other samples listed in Table 2.
Example 6
[0058] Salt induced loss of viscosity of a water soluble compound in a cross-linked thickener in water can be determined by the following protocol. Three compositions: 1) 0. 5 wt. % CARBOPOL™ 2020 neutralized and the remainder water, 2) 0.5 wt. % CARBOPOL™ 2020 neutralized, 0.1 wt. % Sodium PCA, and the remainder water, and 3) 0.5 wt. % CARBOPOL™ 2020 neutralized with 0.1 wt. % Sodium PCA and 1 wt. % EO 11 BO 11 block copolymer, and the remainder water, are created. All percentages are based on the weight of water. The viscosity of each composition is measured at a temperature of 24° C. using a Brookfield LV viscometer.
[0059] CARBOPOL™ polymers are cross-linked polymers of acrylic acid which are commonly used as thickeners for lotions. It is well known that the thickening property will drastically reduce when a salt is introduced into the lotion formulation. Sodium-2-pyrrolidone carboxylate (Sodium PCA) salt is a commonly used moisturizer for hair and skin care products.
[0060] Substantially following the above protocol, the following results were obtained and are reported in TABLE 3.
[0000] TABLE 3 Viscosity Sample Ingredients of composition, in addition to water (mPa · s) 8 0.5 wt. % CARBOPOL ™ 2020 neutralized 39151 9 0.5 wt. % CARBOPOL ™ 2020 neutralized 14328 and 0.1 wt. % Sodium PCA 10 0.5 wt. % CARBOPOL ™ 2020 neutralized, 37650 0.1 wt. % Sodium PCA and 1 wt. % EO 11 BO 11 block copolymer
As shown in TABLE 3, by encapsulating the sodium-2-pyrrolidone carboxylate in the block copolymer EO 11 BO 11 , the viscosity of the formulation designated sample 10 can be maintained to a substantial degree as compared to the salt free sample 8.
Example 7
[0061] The skin irritation of an aqueous composition comprising 5 weight percent of glycolic acid in the absence or presence of 1 weight percent of the block copolymer EO 11 BO 11 can be determined by the following protocol.
[0062] The solution is applied onto the dorsal part of the forearm of 10 panelists, spread evenly in a 3 inch area and left on the arm for about 10 minutes. On one arm an aqueous solution A) comprising 5 weight percent of glycolic acid is applied, on the other arm an aqueous solution B) comprising 5 weight percent of glycolic acid and 1 weight percent of the block copolymer EO 11 BO 11 is applied, without disclosing the composition of the solutions to the panelists. Then the panelists are asked to identify which arm feels more irritated, by asking which arm feels less burning sensation.
[0063] Substantially following the above protocol, the following results were obtained. All panelists indicated that the arm to which solution B) has been applied felt less burning sensation. Thus, encapsulation of 5 weight percent of glycolic acid appears to lessen any skin irritation effects.
[0064] It is understood that the present invention is not limited to the embodiments specifically disclosed and exemplified herein. Various modifications of the invention will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the appended claims.
[0065] Moreover, each recited range includes all combinations and subcombinations of ranges, as well as specific numerals contained therein. Additionally, the disclosures of each patent, patent application, and publication cited or described in this document are hereby incorporated herein by reference, in their entireties.
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Aqueous compositions comprising hydrophilic actives and block copolymers comprising at least one block of copolymerized ethylene oxide and at least one block of a polymerized alkylene oxide, the alkylene comprising at least 4 carbon atoms, are described, along with methods of stabilizing hydrophilic actives and methods of increasing compatibility among hydrophilic actives.
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FIELD OF THE INVENTION
The present invention relates to a manufacturing method of diorganopolysiloxane having a functional group at only one end of the molecular chain. Specifically, the invention relates to a manufacturing method of diorganopolysiloxane having a functional group at only one end of the molecular chain of high purity.
BACKGROUND OF THE INVENTION
A diorganopolysiloxane which has a functional group at only one end of the molecular chain can be copolymerized with organic monomer by utilizing the reactivity of the functional group. The siloxane is a useful modifier of the organic resins since it can impart characteristics of organopolysiloxane, such as weather resistance, surface water repellent characteristics, lubricity and as permeability to the organic resin.
A manufacturing method for the preparation of such a diorganopolysiloxane having a functional group at only one end of the molecular chain has been proposed wherein cyclic trisiloxane is subjected to a nonequilibrium polymerization reaction with alkyl lithium, or lithiumsilanolate, as the polymerization initiator, either in the presence or absence of organosilane or organosiloxane which is capped at one end with hydroxyl group and acts as a molecular weight regulator. This nonequilibrium polymerization reaction is terminated by the addition of acid or organo functional group-containing organochlorosilane (refer to JP (Kokai) 59.78236, JP (Kokai) 1-131247, JP (Kokai) 2-92933). However, when the diorganopolysiloxane having a functional group at only one end of the molecular chain obtained by this manufacturing method is copolymerized with organic monomer, there have been such problems as the drastic increase of viscosity during the reaction. In particular, even gelation can occur when the diorganopolysiloxane has molecular weight greater than 10,000. Furthermore, unreacted organopolysiloxane remains after the reaction. In order to study the cause of these problems, the present inventor analyzed such diorganopolysiloxanes having a functional group at only one end of the molecular chain by gel permeation chromatography. It was confirmed that, in addition to the primary peak attributable to such diorganopolysiloxane having a functional group at only one end of the molecular chain, a secondary peak was observed on the higher molecular weight side of the primary peak. Further, the proportion of this secondary peak increased with increasing molecular weight of the diorganopolysiloxane having a functional group at only one end of the molecular chain. It was concluded from these results that the diorganopolysiloxane obtained by the manufacturing method described above contains diorganopolysiloxane having functional groups at both ends and diorganopolysiloxane having functional group at neither end as impurities. Consequently, a manufacturing method for preparing diorganopolysiloxane having a functional group at only one end of the molecular chain of high purity, without forming these by-products, is needed.
The present inventor previously proposed a manufacturing method of diorganopolysiloxane having a functional group at only one end of the molecular chain wherein the nonequilibrium reaction is carried out after a small amount of silanol group-containing impurities existing in the cyclic trisiloxane, used as the raw material of polymerization, are silylated in advance. This method has been effective to inhibit the secondary production of diorganopolysiloxane having functional groups at both ends caused by the silanol group-containing impurities in the cyclic trisiloxane. However, it has not been possible by this method to completely inhibit the secondary production of diorganopolysiloxane having functional group at neither end or diorganopolysiloxane having functional groups at both ends caused by the dimerization or equilibration reaction of α-hydroxydiorganopolysiloxane, which occurs as the side reaction during the polymerization of cyclic trisiloxane.
SUMMARY OF THE INVENTION
The present inventor has discovered that, when the conventional nonequilibrium polymerization reaction is carried out in the presence of a nitrile compound or an ester compound and also a polar solvent which does not contain activated hydrogen, the ratio of side reaction described above is extremely small. The objective of the present invention is to present a manufacturing method for preparing diorganopolysiloxane having a functional group at only one end of the molecular chain in high purity and in high yield.
The present invention therefore relates to a manufacturing method for preparing a diorganopolysiloxane having a functional group at only one end of the molecular chain and having the general formula: R(R 2 SiO) p B wherein R is an identical or different monovalent hydrocarbon group, B is a hydrogen atom or organosilyl group of the formula --SiR 2 R' in which R is an identical or different monovalent hydrocarbon group, and R' is a hydrogen atom or an organic functional group, and p is an integer having a value of at least 1. The method comprises (I) polymerizing (A) cyclic trisiloxane of the general formula ##STR1## wherein R is an identical or different monovalent hydrocarbon group, optionally in the presence of (B) an organosilane or organosiloxane shown by the general formula R(R 2 SiO) m H in which R is an identical or different monovalent hydrocarbon group, and m is an integer of at least 1, using (C) a lithium compound catalyst of the formula R(R 2 SiO) n Li, in which R is an identical or different monovalent hydrocarbon group, and n is an integer of at least 0, and subsequently (II) terminating the above non-equlibrium polymerzation reaction using (D) an acid or an organohalogenosilane of the formula R'R 2 SiX, in which R is an identical or different monovalent hydrocarbon group, R' is a hydrogen atom or an organic functional group, and X is a halogen atom, wherein the above non-equilibrium polymerization reaction (I) is carried out in the presence of (E) a nitrile compound or ester compound and (F) a polar solvent which does not contain activated hydrogen.
The present invention has been disclosed in Japanese Laid Open Patent Application Number Hei 06-113951(94) the full disclosure of which is hereby incorporated by reference.
DETAILED DESCRIPTION OF THE INVENTION
The (A) constituent used in the present invention, cyclic trisiloxane, is the one known as the monomer for nonequilibrium polymerization reaction. In the above formula for this cyclic siloxane, R is an identical or different monovalent hydrocarbon group. Specifically, R can be an alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, or hexyl group; an alkenyl group such as vinyl group, allyl group, or hexenyl group; or an aralkyl group such as benzyl group or phenethyl group. R is preferably a methyl group or vinyl group for ease of manufacture. The cyclic trisiloxane is examplified by 1,1,3,3,5,5-hexamethylcyclotrisiloxane, 1,1,3,3,5,5-hexaphenylcyclotrisiloxane, 1,1,3,3,5,5-hexavinylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5triphenylcyclotrisiloxane, 1,3,5-triethyl-1,3,5-trimethylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5-tripropylcyclotrisiloxane, and 1,3,5-trimethyl-1,3,5-triphenethylcyclosiloxane. The above cyclic trisiloxane usually contains as impurities small amounts of silane or siloxane which contains at least 2 silanol groups. It is therefore preferable to silylate these silanol groups with a silylation agent before carrying out the nonequilibrium polymerization reaction, as was proposed by the present inventor in JP (Application) 5-151052. The silylation agent can be a silylation agent which contains halogen atoms bonded to silicon atoms. Examples include chlorosilanes such as trimethylchlorosilane, dimethyldichlorosilane, phenyldimethylchlorosilane, and t-butyldimethylchlorosilane; bromosilanes such as trimethylbromosilane, and triethylbromosilane. The silylation agent can also contain nitrogen atoms bonded to silicon atoms. Examples of this type include silazanes such as hexamethyldisilazane; and silylamines such as dimethylaminotrimethylsilane, diethylaminotrimethylsilane, and trimethylsilylimidazole; and silylamides such as bis (trimethylsilyl) acetoamide; trimethylsilyldiphenylurea, and bis (trimethylsilyl) urea.
The (B) constituent used in the present invention (i.e., organosilane or organosiloxane) is used as needed to adjust the molecular weight of the diorganopolysiloxane having a functional group at only one end of the molecular chain. Component (B) has the general formula R(R 2 SiO) m H, wherein R has its previous definition, and m is an integer having the value of at least 1, and preferably a value of 1-20. Examples of the organosilane include trimethylsilanol, dimethylvinylsilanol, dimethylphenylsilanol, and triphenylsilanol. Examples of the above organosiloxane include dimethylsiloxane capped with hydroxydimethylsiloxy group at one end and with trimethylsiloxy group at the other end, methylphenylsiloxane capped with hydroxydimethylsiloxy group at one end and with trimethylsiloxy group at the other end, methylphenylsiloxane capped with hydroxydiphenylsiloxy group at one end and with trimethylsiloxy group at the other end, methylphenylsiloxane capped with hydroxydimethylsiloxy group at one end and with dimethylvinylsiloxy group at the other end, methylphenylsiloxane-methylvinylsiloxane copolymer capped with hydroxydimethylsiloxy group at one end and with trimethylsiloxy group at the other end, and methylphenylsiloxane-diphenylsiloxane copolymer capped with hydroxydimethylsiloxy group at one end and with trimethylsiloxy group at the other end. These organosilanes or organosiloxanes can be manufactured, for example, by careful hydrolysis of organomonochlorosilanes, or diorganopolysiloxanes which have halogen atom bonded to silicon atom only at one end of the molecular chain, the hydrolysis taking place in a basic dilute aqueous solution.
The lithium compound (C) acts as catalyst for the nonequilibrium polymerization reaction of the (A) constituent or of the (A) constituent and the (B) constituent. This catalyst has the general formula R(R 2 SiO) n Li, wherein R is an identical or different monovalent hydrocarbon group as defined above. In this formula, n is an integer having a value of at least 0. When n is 1 or greater, it is preferred to have a value of 1-20 for the ease of manufacture. When n is 0, this constituent is an organic lithium compound which is available commercially, and can be easily obtained. On the other hand, when n is an integer 1 or greater, this constituent is lithium silanolate or lithium siloxanolate. The manufacturing methods of these lithium silanolates or lithium siloxanolates are known. For example, they can be obtained by reacting a silanol group-containing organosilane or organosiloxane, such as the (B) constituent, with a lithium compound and forming their respective lithium derivatives. Also, the lithium compound catalyst containing unreacted silanol group-containing organosilane or organosiloxane, obtained by reacting less moles of lithium compound than moles of the silanol groups, can be used as the mixture of the (B) constituent and the (C) constituent. The lithium compound catalyst (C) can be an alkyl lithium such as n-butyl lithium, s-butyl lithium, t-butyl lithium, and methyl lithium; an aryl lithium such as phenyl lithium and xylyl lithium; an alkenyl lithium such as vinyl lithium and allyl lithium; or a lithium salt of an organosilane or an organosiloxane such as lithium trimethylsilanolate, lithium dimethylvinylsilanolate, and lithium triphenylsilanolate. The lithium compound used to prepare lithium silanolate or lithium siloxanolate can also be a lithium amide such as lithiumbis(diisopropyl)amide.
The lithium compound catalyst (C) is used in sufficient amount to cause the ring opening reaction of the cyclic trisiloxane (A). This catalyst is added in such an amount that its molar ratio to the (B) constituent is 100/0 to 0.01/100. Also, for the case when the silylation agent is used for silylation of the silanol group-containing impurity in the (A) constituent, the addition should be preferably in such an amount that the molar ratio of the lithium compound catalyst remaining after the silylation to the (B) constituent is 100/0 to 0.01/100. Furthermore, if this ratio is 0.5/99.5 to 50/50, an appropriate reaction rate of the nonequilibrium polymerization reaction can be obtained, the manufacturing efficiency is improved, and the expensive lithium compound catalyst can be saved.
The (D) constituent used in the present invention, acid or organohalogenosilane, is the constituent used to terminate the nonequilibrium polymerization reaction described above, and it forms a stable lithium salt by reaction with lithium silanolate. The acid can be a mineral acid such as wet carbonic acid gas, hydrochloric acid or sulfuric acid; or a caroxylic acid such as acetic acid, propionic acid, or acrylic acid. The organohalogenosilane (D) has the general formula R'R 2 SiX wherein R is an identical or different monovalent hydrocarbon group, as defined above. R' is a hydrogen atom or organic functional group. Specifically, R' can be an alkenyl group such as vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, and heptenyl group; a 3-methacryloxypropyl group, a 3-acryloxypropyl group, or a 3-chloropropyl group, In the above formula, X is a halogen atom. Examples of organohalogenosilane (D) include dimethylchlorosilane, dimethylvinylchlorosilane, 3-methacryloxypropyldimethylchlorosilane, or 3-chloropropyldimethylchlorosilane.
When acid such as wet carbonic acid gas, mineral acid or carboxylic acid is used as constituent (D) to terminate the above nonequilibrium polymerization reaction, a a diorganopolysiloxane having a silanol group at only one end of the molecular chain is obtained. When an organo functional group-containing organohalogenosilane is used as constituent (D) to terminate the above nonequilibrium polymerization reaction, a diorganopolysiloxane having one end capped with silyl residue (i.e., the remainder of the organo functional group-containing organohalogenosilane from which halogen atoms are removed), is obtained. When halogenosilane, containing hydrogen atom bonded to silicon atom, such as dimethylchlorosilane, is used as constituent (D) to terminate the above nonequilibrium polymerization reaction, a diorganopolysiloxane having one end capped with hydrogen atom bonded to silicon atom is obtained. Further, by addition reaction of this diorganopolysiloxane having hydrogen atom bonded to silicon atom at one end, and an organo functional group-containing alkenyl compound such as allylglycidylether, allylamine, allyl alcohol, trimethylolpropanemonoallylether, glycerolmonoallylether, allylmethacrylate, and the like, in the presence of hydrosilation reaction catalyst such as platinum base catalyst, it is possible to manufacture a diorganopolysiloxane having one end capped with organo functional group bonded to silicon atom. In this process, the organo functional group can be protected by a protecting group such as trimethylsilyl group, as needed. After the addition reaction is completed, this protecting group can be detached. Also, by dehydrohalogenation reaction by adding the organic functional group-containing organohalogenosilane of constituent (D) to the diorganopolysiloxane having a silanol group at only one end of the molecular chain obtained by using acid as constituent (D), it is possible to manufacture a diorganopolysiloxane having one end capped with an organo functional group bonded to silicon atom. In this case, a hydrogen halide scavenger such as an organic amine compound or ammonia is preferrably added.
The (E) constituent used in the present invention, nitrile compound or ester compound, functions to inhibit the formation of by-products during the nonequilibrium polymerization reaction. The nitrile compound and the ester compound, respectively, can be used individually as constituent (E). A mixture of the nitrile compound and the ester compound can also be used. The nitrile compound can be acetonitrile, propionitrile, succinonitrile, butyronitrile, isobutyronitrile, valeronitrile, and α-tolunitrile, and a mixture of two or more of these can be used as well. Among these, acetonitrile is the most preferable considering the ease of removal after the end of the nonequilibrium polymerization reaction and its economy and toxicity. The ester compound can be acetic acid esters such as methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, isopentyl acetate, cyclohexyl acetate, and benzyl acetate; propionic acid esters such as methyl propionate, ethyl propionate, butyl propionate, and isopentyl propionate; or the mixtures of two or more of these. Of the Ester compounds, acetic acid ester is preferred, methyl acetate and ethyl acetate being most preferable considering the ease of removal after the end of the nonequilibrium polymerization reaction, and the economy. Use of nitrile compound described above is preferred for component (E).
The (F) constituent, polar solvent not containing activated hydrogen, is used to promote the nonequilibrium polymerization. This solvent can be tetrahydrofuran, 1,4-dioxane, ethyleneglycoldimethylether, diethyleneglycoldimethylether, dimethylformamide, dimethyl sulfoxide, or hexamethylphosphoric triamide, or a mixture of two or more of these. Among these, tetrahydrofuran, dimethylformamide, and dimethyl sulfoxide are preferred considering their ability to promote the nonequilibrium polymerization, the ease of removal after the end of the nonequilibrium polymerization reaction, and the economy. Since the ability to promote the nonequilibrium polymerization varies as a function of the type of constituent (F) used, the amount to be added is generally determined by routine experimentation. For example, when 1,1,3,3,5,5-hexamethylcyclotrisiloxane is used as the (A) constituent, and constituent (F) is tetrahydrofuran, its amount is preferably 50 to 200% relative to the siloxane; if (F) is dimethyl sulfoxide, its amount is preferably 0.5 to 5 %; and if (F) is dimethylformamide, its amount is preferably 1 to 10again relative to the siloxane.
In the manufacturing method of the present invention, the reaction temperature and the reaction time of the nonequilibrium polymerization reaction are not particularly limited, but is necessary to adjust them carefully enough not to cause equilibrium polymerization (i.e., redistribution reaction). Thus, if the equilibrium polymerization occurs diorganopolysiloxane, capped with lithium silanolate groups or silanol groups at both ends as well as diorganopolysiloxane, in which neither end is capped with lithium silanolate group or silanol group, are formed as by-products. When 1,1,3,3,5,5-hexamethylcyclotrisiloxane is used as the (A) constituent, a preferable condition for this nonequilibrium polymerization reaction is at the temperature of 0 to 40° C. for 1 to 50 hours.
The progress of the non-equilibration polymerization reaction in the preparation method according to the present invention can be followed by monitoring the decrease in component (A) by an analytical means such as gas chromatography and the like. This non-equilibration polymerization reaction is preferably stopped by the addition of component (D) when the component (A) conversion has reached a desired value. While the component (A) conversion must be adjusted to the nature of component (A) and the nature of the monoterminal-functional diorganopolysiloxane product, this conversion will generally be 50 to 100% and preferably 70 to 90%
Also, although the nonequilibrium polymerization reaction can be carried out without using any solvent other than the (E) constituent and the (F) constituent, it is preferable to add an aprotic solvent in order to carry out the nonequilibrium polymerization reaction in a homogeneous condition. The aprotic solvent, which can be used, may be an aromatic solvent such as toluene and xylene; or an aliphatic solvent such as hexane, heptane, and cyclohexane. Prior to the nonequilibrium polymerization reaction described above, it is necessary to remove moisture from each constituent and each solvent as much as possible. If moisture exists in a constituent or solvent, organopolysiloxane which is capped with lithium silanolate groups or silanol groups at both ends is formed as by-product.
The diorganopolysiloxane having a functional group at only one end of the molecular chain manufactured by the method of the present invention has the general formula R(R 2 SiO) p B. In this formula, R is an identical or different monovalent hydrocarbon group, as defined above. B is a hydrogen atom or an organosilyl group of the formula --SiR 2 R', wherein R is the same as described above, and R' is a hydrogen atom or an organo functional group, as defined above and p is an integer having a value of at least 1. The molecular weight of this diorganopolysiloxane is determined by the ratio of the (B) constituent and the (C) constituent existing in the system during the nonequilibrium polymerization reaction relative to the (A) constituent consumed.
Since the content of impurities such as diorganopolysiloxane having functional groups at both ends or diorganopolysiloxane having functional group at neither end is extremely low in the diorganopolysiloxane having a functional group at only one end of the molecular chain obtained by the manufacturing method of the present invention, even if this diorganopolysiloxane is subjected to a copolymerization reaction with an organic monomer, there is no drastic increase in viscosity during the reaction, let alone gelation. Consequently, it is useful as a modifier for various organic polymers, for example, as a modifier to add lubricity, weather resistance, moisture proof, gas permeability, inter alia.
EXAMPLES
In the following, the present invention is explained in detail by Examples. The number average molecular weight and polydispersity of the organopolysiloxane having a functional group at only one end of the molecular chain are calibrated values based on standard polystyrene gel permeation chromatography. Also, trimethylsilanol, dimethylformamide, acetonitrile, and ethyl acetate used in the Examples were dried in advance.
Example 1
1,1,3,3,5,5-hexamethylcyclotrisiloxane (100 grams; 449.5 millimoles) and toluene (75 grams) were mixed and subjected to azeotropic dehydration for 1 hour. After dehydration, the solution was cooled to room temperature, and 1.63 N hexane solution of n-butyl lithium (2.0 milliliters; n-butyl lithium=3.26 millimoles) was added and stirred for 10 minutes at room temperature. Subsequently, trimethylchlorosilane (0.336 gram; 3.1 millimoles) was added and stirred for 5 minutes at room temperature. A mixture of trimethylsilanol (0.741 gram; 8.23 millimoles), dimethylformamide (8.0 grams) and acetonitrile (25.0 grams) was then added and a white precipitate formed as the nonequilibrium polymerization reaction started. After the start of the reaction, at the passage of fixed times (5.5 hours, 8 hours, 22.17 hours), the reaction mixture was sampled and its nonequilibrium polymerization reaction was terminated by adding a drop of acetic acid, and dimethylpolysiloxane having a functional group at only one end of the molecular chain was obtained. From the dimethylpolysiloxane having a functional group at only one end of the molecular chain obtained, the conversion of 1,1,3,3,5,5-hexamethylcyclotrisiloxane was tracked by gas chromatography (hereafter GLC). Also, the number average molecular weight and the polydispersity of the silanol group-functional dimethylpolysiloxane obtained were tracked by gel permeation chromatography (hereafter GPC). These results are shown in Table 1.
Also, to the reaction mixture after 5.5 hours from the start of the reaction, diethylamine and methacryloxypropyldimethylchlorosilane were added in order, and heated and stirred at 60° C. for 2 hours. The by-product salts were then filtered out, and low boiling point substance was distilled off by heating under reduced pressure. After cooling, the precipitated salts were further filtered out and dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain was obtained. According to analysis by GPC of this dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain, its number average molecular weight was 10,723 and the polydispersity was 1.04.
TABLE 1______________________________________ 22.1Reaction time (hrs) 5.5 8 7______________________________________Conversion of 1,1,3,3,5,5- 79.8 88.6 99.6hexamethylcyclotrisiloxane (%)Dimethylpolysiloxane having a silanolgroup at only one end of the molecularchainNumber average molecular weight 10525 11770 13210(Mn)Polydispersity = Mw/mn 1.04 1.04 1.08______________________________________
Comparison Example 1
Nonequilibrium polymerization reaction was carried out in the same way as Example 1 except that the amount of addition of dimethylformamide was 4.0 grams and acetonitrile was not added. After various times (6.17 hours, 8 hours, 22 hours), the reaction mixture was sampled, and in the same way as Example 1, dimethylpolysiloxane having a silanol group at only one end of the molecular chain was obtained. From the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained, the conversion of 1,1,3,3,5,5-hexamethylcyclotrisiloxane was tracked by GLC. Also, the number average molecular weight and the polydispersity of the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained were tracked by GPC. These results are shown in Table 2.
Also, to the reaction mixture after 6.17 hours from the start of the reaction, diethylamine and methacryloxypropyldimethylchlorosilane were added in order and, in the same way as Example 1, dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain was obtained. According to the analysis by GPC of the dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain obtained, its number average molecular weight was 11,952 and the polydispersity was 1.06.
TABLE 2______________________________________Reaction time (hrs) 6.17 8 22______________________________________Conversion of 1,1,3,3,5,5- 80.5 86.9 99.7hexamethylcyclotrisiloxane(%)Dimethylpolysiloxane having a silanolgroup at only one end of the molecularchainNumber average molecular weight 11243 12328 13819(Mn)Polydispersity = Mw/Mn 1.05 1.05 1.13______________________________________
Example 2
Nonequilibrium polymerization reaction was carried out in the same way as Example 1 except that dimethyl sulfoxide (2.0 grams) was used instead of the dimethylformamide in Example 1. After various times (3.83 hours, 5.33 hours, 22 hours), the reaction mixture was sampled, and in the same way as Example 1, dimethylpolysiloxane having a silanol group at only one end of the molecular chain was obtained. From the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained, the conversion of 1,1,3,3,5,5-hexamethylcyclotrisiloxane was tracked by GLC. Also, the number average molecular weight and the polydispersity of the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained were tracked by GPC. These results are shown in Table 3.
TABLE 3______________________________________Reaction time (hrs) 3.83 5.33 22______________________________________Conversion of 1,1,3,3,5,5- 80.6 90.4 100hexamethylcyclotrisiloxane(%)Dimethylpolysiloxane having a silanolgroup at only one end of the molecularchainNumber average molecular weight 9953 11133 12883Polydispersity 1.05 1.05 1.10______________________________________
Comparison Example 2
Nonequilibrium polymerization reaction was carried out in the same way as Example 2 except that acetonitrile was not used. After various times (3.25 hours, 4.5 hours, 22 hours), the reaction mixture was sampled, and in the same way as Example 2, dimethylpolysiloxane having a silanol group at only one end of the molecular chain was obtained. From the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained, the conversion of 1,1,3,3,5,5-hexamethylcyclotrisiloxane was tracked by GLC. Also, the number average molecular weight and the polydispersity of the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained were tracked by GPC. These results are shown in Table 4.
TABLE 4______________________________________Reaction time (hrs) 3.25 4.5 22______________________________________Conversion of 1,1,3,3,5,5- 80.5 90.1 100hexamethylcyclotrisiloxane(%)Dimethylpolysiloxane having a silanolgroup at only one end of the molecularchainNumber average molecular weight 11037 11525 11077Polydispersity 1.06 1.08 1.59______________________________________
Example 3
Nonequilibrium polymerization reaction was carried out in the same way as Example 1 except that ethyl acetate (25 grams) was used instead of the acetonitrile in Example 1. After various times (3.08 hours, 4.32 hours, 22 hours), the reaction mixture was sampled, and in the same way as Example 1, dimethylpolysiloxane having a silanol group at only one end of the molecular chain was obtained. From the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained, the conversion of 1,1,3,3,5,5-hexamethylcyclotrisiloxane was tracked by GLC. Also, the number average molecular weight and the polydispersity of the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained were tracked by GPC. These results are shown in Table 5. ##STR2##
Comparison Example 3
Nonequilibrium polymerization reaction was carried out in the same way as Example 3 except that ethyl acetate was not used. After various times (3 hours, 4.17 hours, 22 hours), the reaction mixture was sampled, and in the same way as Example 3, dimethylpolysiloxane having a silanol group at only one end of the molecular chain was obtained. From the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained, the conversion of 1,1,3,3,5,5-hexamethylcyclotrisiloxane was tracked by GLC. Also, the number average molecular weight and the polydispersity of the dimethylpolysiloxane having a silanol group at only one end of the molecular chain obtained were tracked by GPC. These results are shown in Table 6.
TABLE 6______________________________________Reaction time (hrs) 3 4.17 22______________________________________Conversion of 1,1,3,3,5,5- 81.2 91.1 100hexamethylcyclotrisiloxane(%)Dimethylpolysiloxane having a silanolgroup at only one end of the molecularchainNumber average molecular weight 11668 12840 14308Polydispersity 1.04 1.05 1.18______________________________________
Application Example
The dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain obtained in Example 1, (7.2 grams), butyl acrylate (16.8 grams) and toluene (30 grams) were mixed under a nitrogen atmosphere. To this mixture, 6 grams of toluene solution, which contained azobisisobutyronitrile (0.06 gram), was added dropwise. After completion of this dropwise addition, the mixture was heated and stirred at 60° C. 29 hours, and a toluene solution of a poly(butyl acrylate) grafted polydimethylsiloxane was obtained. Using a Fourier transform infrared spectrophotometer as the detector and the characteristic absorption of SiMe 2 group at 800˜810 cm -1 as the detecting wavelength, GPC measurement (hereafter GPC FT-IR) of the toluene solution of poly(butyl acrylate) grafted polydimethylsiloxane, was carried out. It was found that 95.8% of the dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain used was copolymerized. By this result, it was found that the purity of dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain obtained in Example 1 was 95.8%. The viscosity of the toluene solution of poly(butyl acrylate) graft-bonded polydimethylsiloxane obtained was 944 centipoises.
For comparison, the dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain obtained in Comparison example 1 was copolymerized with butyl acrylate in the same manner as described above. By GPC FT-IR analysis of the toluene solution of poly(butyl acrylate) grafted polydimethylsiloxane, it was found that 91.4% of the dimethylpolysiloxane used was copolymerized. By this result, it was found that the purity of dimethylpolysiloxane having a methacryloxy group at only one end of the molecular chain obtained in Comparison example 1 was 91.4%. The viscosity of the toluene solution of poly(butyl acrylate) graft-bonded polydimethylsiloxane was 2,500 centipoises.
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There is disclosed a method for preparing a diorganopolysiloxane having a functional group at only one end of the molecular chain and having the formula
R(R.sub.2 SiO).sub.p B
wherein R is an independently selected monovalent hydrocarbon group, B is selected from the group consisting of a hydrogen atom and an organosilyl group having the formula
--SiR.sub.2 R'
in which R is as defined above, R' is selected from the group consisting of a hydrogen atom and an organic functional group and p is an integer having a value of at least 1, said method comprising:
(I) polymerizing
(A) a cyclic trisiloxane, using
(C) a lithium compound catalyst, said polymerization reaction taking place in the presence of
(D) a compound selected from the group consisting of a nitrile compound and an ester compound and
(E) a polar solvent which does not contain activated hydrogen; and
(II) terminating the nonequilibrium polymerization reaction product obtained from step (I) using
(F) a compound selected from the group consisting of an acid and an organohalogenosilane.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Continuation-in-Part claims the benefit of Non-provisional application Ser. No. 11/413,317 filed on Apr. 28, 2006
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0003] Not Applicable
BACKGROUND
[0004] The present invention relates generally to building toys and, more particularly, to indoor and all-season outdoor coupleable/decoupleable modular construction toys.
[0005] The background information discussed below is presented to better illustrate the novelty and usefulness of the present invention. This background information is not admitted prior art.
[0006] The market for toys and games is a booming industry in the United States and around the world. Nearly $40 billion dollars each year is spent on the newest and most popular games and toys, and since deregulation of children's television in 1984, there has been an explosion of multi-media based toys. At least half of all new toys this year are projected to be such toys and it is predicted that this ratio will grow.
[0007] In addition to multi-media based toys; there is an abundance of electronic games and gadgets aimed at getting a child's attention. These toys are known to have deleterious effects on children. Many of these toys encourage imitative play that can promote undesirable behavior in children, especially when the toys are based on television shows and movies that promote violence as they often lead children into imitating the violence in their play.
SUMMARY
[0008] The present inventor realized that most the new toys and/or games coming on the market, regardless of how costly, do not hold a child's interest for long. The Inventor concluded this is due, in part, to the fact that more and more toys are designed for “imitative” play where a child is encouraged to imitate characters made popular by the television shows, movies, and books. Imitative toys present an ordered activity of play that undermine a child's imagination, creativity, and ability to recognize and appreciate interesting problems to explore and solve. Examples of such ordered activity toys include computer based toys and games that usually result in children sitting passively indoors for hours, instead of being involved in active outdoor play. Moreover, many of these presently available toys are provided with a comprehensive set of game playing rules that leave little room for independent thinking undermining active play and discouraging creativity. The present inventor theorized that a child's interest in playing with a toy would be extended if the child's imagination had to be utilized in order to play with the toy.
[0009] As a parent, who also happens to be trained in the medical field, the present Inventor appreciates the beneficial and therapeutic effects that imaginative play, especially outdoors imaginative play, activity promotes. Physical activity helps children sleep better at night and helps battle the obesity epidemic among America's youngsters. Moreover, physical activity may help reduce hyperactivity in children. When a child in involved in an activity that requires both mental and physical activity his and her level of independence, resourcefulness, and competence grow, which of course helps the children to develop into positively oriented, creative, and competent adults.
[0010] The present inventor studied the many attempts to provide toys that encourage active, creative, outdoors play. One set of such toys include inflatable toys and injection molded boats or polyurethane foam floating toys of various shapes for use in water areas, such as in swimming pools or at the beach. Injection molded plastic floating toys while providing some incentive for summer time activity, are not only costly, which seems even costlier in northern climates where their period of use is limited, but their creative stimulation value is minimal at best. A similar situation exits with expensive inflatable winter sledding toys, which can be used only for the snowy months of the year. Moreover, both of these seasonal toys require storage during their “off” seasons and as children physically and developmentally outgrow such toys within a few years, their lifespan is limited.
[0011] One attempt at providing for a multiple use outdoors toy offers a convertible, floatable toy that can be used either in the water or for downhill sledding and comes is equipped with steering capability and contains interchangeable parts, which include a water propulsion means or ski runners. While this toy has the versatility of use in the water as a floatation device or in the snow as a sled, it serves no purpose as a toy in any other environment. So, while its dual nature may save parents some expense, and while it may encourage children to play outdoors, this device must be used either in water or on snow and only minimally does it encourage a child's creativity. Additionally, its interchangeable parts offer only two toys for the price of one.
[0012] Another attempt at providing for an outdoors toy with multiple uses is a multi-season ski sled for use in skiing and sledding. The ski sled is not used for conventional skiing because the user's feet are not fixed to the ski runners. Instead, the “ski sled” refers to the use of a ski runner for sliding over the snow or the use of ski runners in fixed parallel or tandem relationship. This invention provides a multi-season ski sled that can be used for skiing or sledding because it also has detachably mounted wheel assemblies that convert the ski sled for scooting use. Although this invention may be used on snow or dry land, it cannot be used in the water, and does not require much creativity.
[0013] Another attempt to fulfill the as yet unmet need is a sled that has a plurality of wheels for use when desired. The sled also has a steering member operatively coupled to at least two of the several pairs of wheels and a hand brake that is attached to the steering member. While this invention is a toy that can serve both as a sled for use on snow or as a sled with wheels for use on dry land or on snow, it cannot be used in the water.
[0014] Accordingly, the present inventor teaches herein a child's toy that encourages children to use their imagination while being fun, safe, and durable. The toy is designed to accommodate a growing child's changing interests and encourages both mental and physical indoor and outdoor activity in all seasons. Moreover the toy provides creative challenging play for children of a range of ages, from young to beyond the teen years.
[0015] The primary toy devised by the present Inventor consists of a basic modular unit having a body section, a perimeter that is, or approximates being equidistant from the center of the unit, and couplers extending out away from the perimeter, A perimeter is herein described as the continuous path that surrounds an area. The term may be thought of as the length of the outline of a shape. The perimeter of a circular area is called circumference. Hence, as used herein a basic unit having a round shape has a circumference that is equidistant from the center of the unit at all points of the circumference. Basic modular units are also contemplated being shaped as regular polygons, for example as having a perimeter that can be defined as a hexagon, octagon, or a similar shape. A regular polygon is defined as an equilateral polygon which is cyclic, that is its vertices are on a circle and thus all of the vertices are equidistant from the center of the unit. This provides for all basic units having or generally having a perimeter that approximates being equi-dimensional from the center of the unit.
[0016] The center of each basic unit is depressed to provide a comfortable seating area for the user regardless if the unit is being used with a flotation device or as sled. The depressed seating area helps to secure the user in the sled preventing the sled user from falling off of the sled.
[0017] The facts that each basic unit is round, or a regular polygon, and that each basic unit has a centrally located depressed seating area results in a weight stable configuration. That is, the weight of the user is kept in the center of the sled, thus stabilizing the user on the sled and also stabilizing the combination of user and sled.
[0018] Each basic unit may be used as is, that is by itself, but also may be used in conjunction with other basic modular units. Each basic unit has one or more couplers extending out from the equi-dimensional, or nearly equi-dimensional, perimeter of each sled. The couplers are used to attach basic units to other basic units. In the example illustrated, the couplers are male/female couplers designed to be an extension off of the perimeter of the basic unit, in that they are formed as part of the basic unit at the time the basic unit is formed but extend out away from the perimeter of the basic unit. One method of manufacture would be by a molding process. The cup-like shape of the couplers provides for each coupler to be used as both a male and a female coupling unit.
[0019] Coupling basic units to each other provides children with an array of construction options, such as the ability to build a multi-user sled, a walled fort, and a domed fort similar to an igloo. Two basic units may be coupled to form a side by side couplet sled. Three sleds may be coupled so that they are arranged in a line and can be used as a train or a line of units extending from the right and/or left of another user. Alternatively, three sleds may be coupled so that a line connecting the center points of each of the sleds describes a triangle. The number of sleds that can be coupled is limited only by the number of users and the space available. The sleds may be used in such configurations because each sled and rider is weight stable due to a user being positioned in the center depression of the unit, as discussed above.
[0020] One series of basic units are sized so that each basic unit fits snuggly, safely, and securely into the open center of any standard sized inflatable, floatable inner-tubes. The fact that the male/female couplers extend out away from the perimeter of the basic unit provide for basic units, even while positioned within an inner-tube to be coupled. In fact a basic unit in an inner-tube can be coupled to another basic unit that is not positioned in an inner-tube.
[0021] The basic units may be coupled to directly each other, as taught above, or through the use of a separate coupler unit. A coupler unit has a triangularly shaped body with female/male couplers on the apex of each of the three vertices. The female/male couplers of the coupler units are shaped and sized to be used with any of the couplers on any of the other basic units.
[0022] The fact that each unit has a set of couplers means that the each unit is attachable to various accessories. For example, the invention includes providing for skis that can be used with a basic unit for skiing on either snow or water. Each ski is equipped with one or more couplers that are couple-able to the couplers of a basic unit.
[0023] When the discs are coupled side by side in a vertical orientation to form a circle, a vertically-walled fort is formed. Basic units may be added to the upper portions of the basic units forming the walls to form a domed fort.
[0024] Another accessory is a turn-table onto which a basic unit may be attached providing for a spinning toy. Attachable to an accepting aperture of the turntable is a propeller sitting atop a long shaft so that while the bottom of the propeller shaft is fitted into and supported by the accepting aperture of the turntable the propeller extends out above a fort made of basic units.
[0025] Also available are a collection of accessories that extend the number of ways the basic unit can be used and that provide an endless array of toys that engage the imagination as well as require physical activity from children, such as sliding toys, tricycle toys, and toys with roofs. Such accessory pieces provide children the options of constructing a more complicated domed fort with helicopter or airplane like appendages, a water or snow ski-able device, tricycles, and floatable devices, including water tricycles. The toys are constructed of buoyant, water and weather resistant materials that provide for the toys to be used indoors or out, winter or summer. As taught herein, the toys encourage active play to help children build and maintain physical strength and endurance. According to the principles of the present invention, the toy also encourages contemplation, imagination, and confidence. Its use is open ended, there is no one way a child should be playing with the toy, its use induces imaginative and creative play. Moreover, the toy inspires children to more deeply explore their imaginations to develop their own creative ideas. Furthermore, use of the toy often presents children with various technical problems allowing and encouraging children to explore various ways to resolve the problems. Once the problem is solved, the child is able to experience pride and satisfaction in their successful problem solving. The various ways in which the toy may be used are limited only by the child's imagination and thus, is likely to maintain a child's interest. The toy may be used equally well by one child or by a number of children. Importantly, the toy is inexpensive to make, partly because it can be produced by common molding techniques using available and low cost materials, so that it is affordable for all.
[0026] Still other benefits and advantages of this invention will become apparent to those skilled in the art upon reading and understanding the following detailed specification and related drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order that these and other objects, features, and advantages of the present invention may be more fully comprehended and appreciated, the invention will now be described, by way of example, with reference to specific embodiments thereof which are illustrated in appended drawings wherein like reference characters indicate like parts throughout the several figures. It should be understood that these drawings only depict preferred embodiments of the present invention and are not therefore to be considered limiting in scope, thus, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:
[0028] FIG. 1 a is a top plan view illustrating a basic unit of the toy of the present invention.
[0029] FIG. 1 b is a perspective view illustrating a basic unit, as shown in FIG. 1 a.
[0030] FIG. 1 c is a cross-sectional view taken along line 1 c - 1 c of FIG. 1 b.
[0031] FIG. 2 a is a top plan view illustrating a coupler-unit of this invention.
[0032] FIG. 2 b is a partial perspective view of the coupler-unit illustrated in FIG. 2 a.
[0033] FIG. 2 c is a side plan view of the coupler-unit, as illustrated in FIGS. 2 a and 2 b.
[0034] FIG. 3 a is a top plan view illustrating another style coupler-unit of this invention.
[0035] FIG. 3 b is a partial perspective view of the coupler-unit illustrated in FIG. 3 a.
[0036] FIG. 3 c is a side plan view of the coupler-unit, as illustrated in FIGS. 3 a and 3 b.
[0037] FIG. 4 a is a top plan view of three basic units each coupled to a coupler-unit.
[0038] FIG. 4 b is a perspective view of two cup-like coupling-means illustrating how the coupling-means couple.
[0039] FIG. 5 a is a top plan view of a basic unit positioned on an inner-tube for use in the water or on the snow or ice.
[0040] FIG. 5 b is a top plan view of four basic units each situated on an inner-tube and each coupled to a basic unit not situated on an inner-tube.
[0041] FIG. 6 a is a partial perspective view illustrating a top side of a short ski having only one coupling-means.
[0042] FIG. 6 b is a partial perspective illustrating a top side of a full length ski having coupling-means on each of its two ends.
[0043] FIG. 6 c is a plan view illustrating a bottom side of a short ski having only one coupling-means.
[0044] FIG. 6 d is a plan view illustrating a bottom side of a full length ski having a coupling-means on each of its two ends.
[0045] FIG. 6 e is a top plan view illustrating a basic unit coupled to an accompanying set of couple-able skis including a set of two full length skis and one short ski.
[0046] FIG. 7 is a perspective view illustrating six basic units coupled to each other forming a vertically-walled structure.
[0047] FIG. 8 is a perspective view showing a domed fort constructed from nine basic units coupled to each other.
[0048] FIG. 9 is a perspective view showing domed fort constructed from thirteen basic units coupled to each other.
[0049] FIG. 10 a is a side plan view illustrating a rotable sitting means.
[0050] FIG. 10 b is a perspective view of the rotable sitting means as illustrated in FIG. 10 a.
[0051] FIG. 11 is a side plan view of the fort as illustrated in FIG. 8 with the front central basic unit removed to show how a helicopter-like toy is constructed using the rotable sitting means as illustrated in FIG. 10 a.
[0052] FIG. 11 a is a side plan view of a multi-use device.
[0053] FIG. 12 is a side plan view of the fort as illustrated in FIG. 9 with front basic unit removed to show how an airplane-like toy is constructed using the rotable sitting means as illustrated in FIG. 10 a with gear means.
[0054] FIG. 13 is a top plan view of a steerable multiple coupled tube-discs sled.
[0055] FIG. 14 a is a side plan view of a coupleable tricycle.
[0056] FIG. 14 b is a perspective view of coupleable tricycle, as illustrated in FIG. 14 a.
[0057] FIG. 14 c is a top plan view of coupleable tricycle as illustrated in FIG. 14 a and FIG. 14 b.
[0058] FIG. 14 d is a plan view of the individual parts used to make the coupleable tricycle, as illustrated in FIG. 14 a , FIG. 14 b , and FIG. 14 c.
[0059] FIG. 15 is a side plan view of a water disc-cycle.
[0060] FIG. 15 a is a side plan view illustrating the construction used to support seat, to secure first and third inner-tube to the seat, and to support sun-roof basic unit.
[0061] FIG. 16 a is a top plan view illustrating yet another style coupler-unit of this invention.
[0062] FIG. 16 b is a side plan view illustrating yet another style coupler-unit of this invention, as illustrated in FIG. 16 a.
A LIST OF REFERENCE NUMERALS AND THE PARTS TO WHICH THEY REFER
[0000]
10 Basic unit of multi-seasonal, multi-use modular construction toy with coupling-means 12 .
12 Cup-shaped coupling-means.
12 a Alternative coupling-means.
12 c Aperture within coupling-means 12 .
12 d Aperture within coupling-means 12 .
12 e Aperture within coupling-means 12 .
12 k Aperture within coupling-means 12 .
14 Body part of basic unit 10 .
16 Upper or sitting surface of 14 .
18 Bottom surface of 14 .
20 Coupler-unit with three coupler-means 12 .
24 Body part of coupler-unit 20 .
30 A second styled coupler-unit with alternative coupler-means 12 a.
34 Body frame part of coupler-unit 30 .
36 Threaded apertures.
50 Tube-disc, a basic unit in combination with inner tube.
55 Inner tube.
55 a A first inner tube.
55 b A second inner tube.
60 Basic unit 10 with skis 64 and 64 s attached via coupling-means 12 .
62 Front side of full length ski with two coupling-means.
62 s Front side of short ski with a coupling-means.
63 Back side of full length ski with two coupling-means.
63 s Back side of short ski with a coupling-means.
64 Full length ski with coupling-means.
64 s Short ski with a coupling-means.
70 A vertically walled structure comprising six coupled basic units.
80 A domed structure comprising nine coupled basic units.
90 A domed structure comprising thirteen coupled basic units.
100 A turn table sitting device.
103 An aperture.
105 Rotable seating platform of 100 .
107 Rotable shaped shaft connecting 105 and 109 a.
109 Base part of 100 .
109 a Top part of base part of 100 .
109 b Bottom part of base part of 100 .
110 Helicopter-like toy.
111 Multi-use device comprising part 122 that may function as part of an oar, paddle, propeller, or support, for example, and shaft part 119 .
115 Rotable connecting part for connecting 120 to 117 .
119 Long, rod-like shaft.
119 a A first long, rod-like shaft.
119 b A second long, rod-like shaft.
120 Airplane-like toy made using 90 .
122 Propeller-like curved blades.
130 Steerable multiple coupled tube-discs sled.
132 Threaded connector means.
132 a Rod shaped connector means.
132 b Coupling connector aperture.
133 Coupleable steering bar.
135 Coupleable sled.
136 Coupleable accessory seat.
136 a Upwardly directed portion of accessory seat 136 .
136 b Coupleable aperture for accepting 136 c.
136 c Coupleable stem for inserting into 136 b.
137 Coupleable backrest.
139 Coupleable sled attachment means.
139 a Washer for coupleable sled attachment means 139 .
139 b Threaded bolt for coupleable sled attachment means 139 .
139 c Nut for coupleable sled attachment means 139 .
140 A coupleable tricycle.
142 Rear wheel.
142 a Outside side of rear tire.
142 b Inside side of rear tire.
142 c Threaded axel receiving aperture of rear tire.
143 Front wheel.
144 Pedals.
145 Rear tire axel.
146 Steering fork.
148 Crank arm.
150 Water disc-cycle.
160 Another style coupler-unit of this invention.
165 Body part of coupler-unit 160 .
166 Casting impressions for making snow or ice cube-like toys.
170 Central open space in 174 for holding axel and to serve as inlet of water.
174 Right side and left side planar wheel cover faces.
[0138] It should be understood that the drawings are not necessarily to scale. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
DETAILED DESCRIPTION
[0139] Referring now, with more particularity, to the drawings, it should be noted that the disclosed invention is disposed to embodiments in various sizes, shapes, and forms. Therefore, the embodiments described herein are provided with the understanding that the present disclosure is intended as illustrative and is not intended to limit the invention to the embodiments described herein.
[0140] The present invention is a toy that provides a range of play choices. The fundamental structure on which all variations are based is what we refer to as the basic unit. In one favored embodiment, illustrated herein, a basic unit comprises a disc-shaped saucer that is available in a smaller size to support one child or in a larger size to support several. It is to be understood that the shape and the size of the basic unit may vary, as desired, and that the invention does not reside in either the shape or the size of the units of the present invention. However, the there are some features upon which the invention relies. In order to provide for the maximum amount of stability each basic unit should be either round or have a shape of a regular polygon. All of the vertices of a regular polygon lie on a common circle (the circumscribed circle) which is what is referred to as the perimeter of the basic units as described herein. These shapes all share the fact that either all points on the circumference (the perimeter) of the basic unit or all of the vertices of the perimeter of the basic unit are equidistant from the center point of the basic unit, which is turn provides the seating position of greatest stability for the user on the unit. Additionally, each unit is made to have a depressed center to provide for a comfortable and secure seating area. By itself, the disc-like device may be used as a sled for gliding on surfaces one equates with winter-like weather. The toy, however, is designed to be much more than a simple saucer or sled. For example, it may also be used in conjunction with a floatation device, such as an inner-tube for use either in winter on the snow or in summer on the water, which will be described in more detail below. As such, the fundamental basic unit of the toy may be fully enjoyed by itself.
[0141] Each fundamental basic toy unit however is provided with coupling means that extend out away from the perimeter of the basic unit so that, when desired, each basic unit may be coupled to other basic units to provide the user with a wide variety of toys. Additionally, the invention includes accessory pieces that further expand the ways the toy may be used. One such accessory is a set of skis where each ski is provided with one or more coupling means that are couple-able with the coupling means on a basic unit. The resulting ski-sled could be used either in winter on the snow or in summer on the water. Furthermore, each of the basic units may be coupled to one or two other basic units to provide for a multi-ski-vehicle toy. Moreover, the basic units may be coupled, either directly, or indirectly using one of a variety of coupling units, to other basic units to provide for a walled or domed forts.
[0142] Turning now to the drawings, FIG. 1 a, a top plan view, illustrates basic unit 10 of the modular construction toy of this invention. In this exemplary illustration, basic unit 10 is presented as a saucer-like disc form having a circumferential perimeter. As mentioned, it is to be appreciated that a modular construction toy basic unit according to the principles of the present invention may assume a variety of shapes, as long as the shapes may be described as polygonal to provide maximum stability for a user on the basic unit, has a depressed central seating area, and is available in a variety of sizes. FIG. 1 a , a planar view, and FIG. 1 b, a perspective view, illustrate coupling means 12 disposed about and extending out and away from the perimeter of body 14 of basic unit 10 . Coupling means 12 in the example illustrated are male to female couplers providing for coupling and decoupling of the basic unit to like coupling-means of at least one other unit, such as another basic unit or other types of units which will be discussed below. Body 14 comprises an upper sitting surface 16 and bottom surface 18 . The embodiment chosen for illustration presents body 14 in the form of a circular disc, which is but one of many possible styles for the basic unit. The convex disc shape of upper sitting surface 16 provides for a depressed comfortable and secure seat for one or more users. In the example illustrated, the basic unit has a round shape, meaning that all points on the perimeter (the circumference) of the body are equidistance from the center. The centering of a user in a centrally located depressed seating area provides for the user to be in a maximum stable position. FIG. 1 c, a cross-sectional view, of the basic unit, illustrates clearly that in this embodiment coupling means 12 are molded as an integral part of the basic unit. FIG. 1 a and FIG. 1 b illustrate eight coupling means positioned proximate to, but extending, out away from the perimeter of the saucer shaped disc. Having the coupling means extending out and away from the perimeter of the body of the unit provides for the modular construction toy basic unit 10 to be linked directly to other like modular construction toy basic units (see FIG. 4 a ).
[0143] It is to be understood that the number of coupling means is not confined to eight coupling means; any number desired will be effective. In the examples illustrated, the coupling means are presented as female/male coupling cups 12 . In this embodiment, coupling cups 12 are shown as cups with both their top and bottom ends open. The bottom ends of the coupling means 12 are open to receive other coupling means for coupling purposes. The top ends of coupling means 12 are open to avoid the coupling cups from becoming packed with snow when the toy is used in the snow.
[0144] FIG. 2 a , a top plan view, and FIG. 2 b , a partial perspective view, illustrate one embodiment of a coupler-unit according to the principles of this invention. Central coupler body 24 of coupler-unit 20 is illustrated having a triangular polygonal perimeter with coupling-means 12 affixed proximate to but extending our and away from said perimeter, wherein coupling-means 12 provide for male or female coupling and decoupling of said coupler-unit to like coupling-means on at least one other unit provided with coupling means. FIG. 2 c a side plan view of the coupler coupling means, illustrates coupling-means 12 molded as an integral part of coupler-unit 20 forming one seamless coupler-unit. As are the coupling means discussed above, the bottom ends of the coupling means 12 of coupler-unit 20 are open to receive other coupling means for coupling purposes. The top ends of coupling means 12 are open to avoid the coupling cups from becoming packed with snow when the toy is used in the snow.
[0145] FIG. 3 a , a top plan view, illustrates another embodiment of a coupler-unit according to the principles of this invention. Right-angled coupler body frame 34 of coupler-unit 30 has coupling-means 12 a affixed at and defining each apex, where coupling-means 12 a provides for male or female coupling and decoupling of said coupler-unit to the cup-like coupling-means found on other coupling units and on the basic units. Unlike the cup-like coupling means described previously, the height of coupling-means 12 a is limited to the height of coupler frame 34 . Looking down into coupling-means 12 a in the top plan view of FIG. 3 a, gives the impression that the coupling-means are open holes because, as can be seen in the side view presented in FIG. 3 b the circumference of coupling-means 12 a increases with depth, whereas in FIG. 3 c , which is a bottom plan view of the coupler coupling unit, both the bottom circumference line and the top circumference line are seen. As are the coupling means discussed above, the bottom ends of the coupling means 12 a of coupler-unit 30 are open to receive other coupling means for coupling purposes. Incised into each of the two arms of coupler unit defining the right angle is a threaded aperture 36 . The use for these apertures will become apparent in the discussion of FIG. 12 .
[0146] FIG. 4 a , a top plan view, illustrates three basic units 10 each coupled to coupler-unit 20 via coupling means 12 forming a multi-person sled. FIG. 4 b , a side plan view, provides an enlarged view of two cup-like coupling-means 12 to illustrate how simple it is to couple and to decouple coupling-means. No tools or special skills are required for coupling. One cup-like coupling means is simply placed under or over another cup-like coupling means to couple. To decouple one cup-like coupling means is simply lifted up from or down away from the cup-like coupling means to which it is coupled. Although, FIG. 4 a illustrates three basic units 10 coupled via coupler-unit 20 the three basic units 10 could just as easily and rapidly be coupled to each other without the use of coupler-unit 20 .
[0147] FIG. 5 a , a top plan view, illustrates basic unit 10 snugly situated on an inner-tube 55 providing tube-disc 50 for use in the water or on the snow or ice. FIG. 5 b , a top plan view, illustrates four basic units 10 each situated on an inner-tube 55 and each coupled directly via coupling means 12 to basic unit 10 not situated on an inner-tube forming a multi-person device for use in the snow or water.
[0148] FIG. 6 a , a partial perspective view, illustrates a top side 62 s of short ski 64 s having only one coupling-means 12 . FIG. 6 b , a partial perspective, illustrates a top side 62 of full length ski 64 having coupling-means 12 on each of its two ends. FIG. 6 c , a plan view, illustrates bottom side 63 s of a short ski 64 s having only one coupling-means 12 . FIG. 6 d , a plan view, illustrates bottom side 63 of full length ski 64 having a coupling-means on each of its two ends. FIG. 6 e , a top plan view, illustrates basic unit 10 coupled to an accompanying set of couple-able skis and including a set of two full length skis 64 and one short ski 64 s providing for ski-disc 60 that can be used to ski on snow or ice or for water skiing.
[0149] For indoor and all-season outdoor play, various numbers of basic units 10 may be coupled together to form structures, such as play forts of varying complexity. FIG. 7 , a perspective view, illustrates six basic units coupled to each other forming vertically-walled structure 70 . FIG. 8 , a perspective view, illustrates nine basic units coupled to each other to form domed fort 80 . FIG. 9 , a perspective view, illustrates thirteen basic units coupled to each other to form more complicated domed fort 90 . Each of the structures illustrated in FIGS. 7-9 are constructed by coupling the coupling means 12 of each basic unit directly to the coupling means of neighboring basic units. The ease by which the coupling and decoupling is accomplished and the light weight of the each of the modules means that even young children are able to build a fort of their imagination.
[0150] FIG. 10 a , a side plan view, and FIG. 10 b , a perspective view, illustrate rotatable, turntable-like sitting device 100 , another accessory part of the indoor and all season outdoor coupleable/decoupleable modular construction toy of the present invention. Rotatable sitting device 100 comprises rotable seating platform 105 rotably attached to shaft 107 that is in turn rotably connected to top cover part 109 a rotably positioned over bottom support part 109 b of base part 109 . Rotatable sitting device 100 is a sit-on-able variation of a turntable. There are a number of known ways to construct turntables in the art and any of these would work within the principle of the present invention. The uses for rotatable sitting device 100 are limited only by the user's imagination. One contemplated use is described below.
[0151] FIG. 11 , which is, in part, a cutaway longitudinal view of the fort illustrated in FIG. 8 with the front central basic unit removed to provide a view of the inside of the fort, also illustrates rotable sitting device 100 positioned within the fort to construct helicopter-like toy 110 . Rotable sitting device 100 comprises base 109 a, connecting shaft 107 , and rotable seat 105 . FIG. 11 a , a side plan view, illustrates multi-use device 111 comprising multi-use part 122 that functions as part of an oar, paddle, propeller, or support, for example, and multi-use shaft part 119 . In the embodiment illustrated, there are also accessory parts long rod-like shaft 119 and rear tire axel 145 that, in this instance, are connected to each other, for example, by screwing their reciprocally receiving threaded ends together or alternatively, if desired to be manufactured without threaded parts, by friction fitting the parts to each other. There are many ways to connect such shafts known to those of ordinary skill in the art and, thus, need not be discussed in any further detail here. One end of the two section rod-like shaft is then connected to rotatable sitting device 100 using, for example, receiving threaded aperture 103 . The opposite end of the elongated, the two section rotable shaft is connected to rotable connecting part 115 to which propeller-like blades 122 are also connected. To make the propeller-like blades 122 spin, a child, for example, may simply sit on rotable seating part 105 of rotatable sitting device 100 and use his or her feet to rotate the seat, which turns the two section shaft, which turns part 115 , which turns the propellers.
[0152] FIG. 12 , a side plan view illustrates airplane-like toy 120 constructed using the fort shown in FIG. 9 . Several of the front basic units of the fort are removed to provide a view of the airplane propeller driving structure constructed within the interior of the fort. To make the airplane propeller driving structure, the inside surface of a first rear tire 142 is positioned against the inside surface of the first right angle defining arm of coupler-unit 30 , as is illustrated in FIGS. 3 a , 3 b , and 3 c , so that the threaded receiving aperture 142 c of first rear tire 142 is aligned with threaded receiving aperture 36 of the first right angle defining arm of coupler-unit 30 , then the inside surface of a second rear tire 142 is positioned against the inside surface of the second right angle defining arm of coupler-unit 30 so that the threaded receiving aperture 142 c of second rear tire 142 is aligned with threaded receiving aperture 36 of the second right angle defining arm of coupler-unit 30 . Next, a first end of rear tire axel 145 is rotably connected to rotable sitting means 100 while the second end of rear tire axel 145 is screwed into threaded receiving aperture 36 of first right angle defining arm of coupler-unit 30 and then into threaded receiving aperture 142 c of rear tire 142 . Similarly, screwed into threaded receiving aperture 36 on the second right angle defining arm of coupler-unit 30 , is a first end of rod-like shaft 119 . Connected to the second end of shaft 119 is rotable connecting part 115 for connecting propeller-like blades 122 .
[0153] FIG. 13 , a top plan view, illustrates a first, second, and third tube-disc 50 coupled to each other and to coupleable sled 135 to form steerable multiple coupled tube-discs sled 130 . In particular, steerable multiple coupled tube-discs sled 130 comprises a first tube-disc 50 coupled via two coupler-means 12 of first coupler-unit 20 to second tube-disc 50 which is coupled via two coupler-means 12 of second coupler-unit 20 to third tube-disc 50 . Coupleable, steerable sled 135 is coupled to second tube-disc 50 via coupleable sled attachment means 139 . Coupleable sled attachment means 139 comprises washer 139 a, threaded bolt 139 b, and nut 139 c (illustrated in FIG. 13 a ). Coupleable steerable sled 135 comprises coupleable accessory seat 136 coupled to first and second full length skies 64 with coupling-means, as described above. The steering of tube-discs sled 130 is accomplished using coupleable steering bar 133 that is coupled to the sled, in this embodiment by screwing steering bar mechanism 133 onto threaded coupleable sled attachment means 139 . A first end of steering bar 133 is adapted to fit into aperture 12 d of the coupling-means 12 of first coupler-unit 20 that is not being used to couple the first and second tube-discs 50 while a second end of steering bar mechanism 133 is adapted to fit into aperture 12 e of the coupling-means 12 of second coupler-unit 20 that is not being used to couple the second and third tube-discs 50 so that moving an end of the steering bar in a desired direction directs the movement the tube-disc functionally attached to that end of the steering bar to move in the desired direction. Optional coupleable backrest 137 may be coupled to coupleable accessory seat 136 providing for a more comfortable ride.
[0154] FIG. 14 a , a side plan view, FIG. 14 b , a perspective view, and FIG. 14 c , a top plan view, illustrate yet still another way the accessory parts of the coupleable construction toy of the present invention may be used for creative construction. In this embodiment, the accessory parts provide for the construction of coupleable tricycle 140 . FIG. 14 d provides a plan view of the individual accessory parts that are used to make coupleable tricycle 140 . In particular, coupleable tricycle 140 comprises coupleable accessory seat 136 adapted for rotably receiving rear axel 145 onto which is mounted the pair of rear wheels 142 . FIG. 14 d illustrates the individual parts used in the construction of the coupleable tricycle, such as threaded axel receiving aperture 142 c located on the inside side 142 b of rear wheel 142 opposite outside side 142 a. Optional backrest 137 may be coupled onto the sitting surface of accessory seat 136 by inserting coupleable stems 136 c into coupleable accepting apertures 136 b. The upwardly directed portion 136 a of accessory seat 136 supports steering fork 146 of conventional construction to be functionally engaged with steering bar mechanism 133 . Front wheel 143 is of conventional construction in that it includes an axle (not shown) that extends outwardly from both planar wheel cover faces 174 of the extent of the wheel through steering fork 146 to be then bent into a pair of oppositely disposed crank arms 148 that in turn support pedals 144 . Front wheel 143 is constructed to function as a tricycle front wheel and as a water cycle wheel (which will be discussed below), therefore the wheel construction includes a right side planar face 174 wheel cover and a left side planar face wheel cover each having opening or aperture 170 in the center. Aperture 170 serves to receive the axle and also serves as an inlet for water when used as part of the water cycle. Instead of ordinary spokes, front wheel 143 has “water wheel blades” 172 that are constructed and function just as the blades or paddles do on a conventional water wheel, however, the only function “water wheel blades” 172 serve coupleable tricycle 140 is to provide support to the wheel and to the tricycle.
[0155] Yet still another imaginative construction that can be constructed using the accessory parts already described with the addition of one other part is water disc-cycle 150 , as illustrated in FIG. 15 . The buoyancy of water disc-cycle 150 is, in part, maintained by a first 55 a, second 55 b, and third inner-tube (third inner-tube is hidden from view behind first inner tube 55 a ). Water disc-cycle 150 comprises accessory seat 136 . Upwardly directed portion 136 a of accessory seat 136 supports steering fork 146 for functional engagement with steering bar mechanism 133 . Front wheel 143 is of conventional construction in that it includes an axle (not shown) that extends outwardly from both planar wheel cover faces 174 of the extent of the wheel through steering fork 146 to be then bent into a pair of oppositely disposed crank arms 148 that in turn support pedals 144 . Front wheel 143 is constructed to function as a water cycle wheel in addition to a tricycle wheel therefore the construction includes a right side planar face cover 174 and a left side planar face wheel cover 174 (mirror image cannot see in illustration) having an aperture in the center. The aperture serves to hold the axle and as an inlet for water when used as part of the water cycle. Instead of spokes, front wheel 143 has “water wheel blades” 172 (see FIGS. 14 b and 14 c ) that are constructed and function just as the blades or paddles do on a water wheel. Peddling pedals 144 in a conventional peddling manner turns water wheel 143 which causes water disc-cycle 150 to be propelled through the water. Opening 170 allows water to be drawn in adding to the amount of water present to turn the wheel. Attached to upwardly directed portion 136 a of accessory seat 136 via rod shaped connector means 132 a is rotable shaft 107 that is in turn connected to seating part 105 that is hooked over the second inner-tube to hold the second inner-tube securely to the cycle. Basic disc 10 provides for a sun roof for the user who sits on accessory seat 136 . Basic disc 10 is supported in its sun roof position by three long, rod-like shafts, of which only 119 a and 119 b can be seen in the figure. FIG. 15 a illustrates the construction used to support seat 136 , to secure first and third inner-tube to seat 136 , and to support sun-roof basic unit 10 . Each end of rear tire axel, which is used as the support for seat 136 is connected to a paddle part 122 via connector attachment means 132 . In particular, the male threaded ends of 145 and 122 and secured into the female threaded accepting part of 132 b forming not only a support for seat 136 , but providing the curved blades 122 that rests on first inner tube 55 and on not seen third inner tube. Moreover, the threaded ends of parts 132 a are now in position to be connected to the complementary threaded ends of shaft 119 a (as a mirror image, and thus not shown, first end of the third shaft is supported by a second propeller-like curved blade that rests on third inner tube) which positions shaft 119 a to be inserted through the coupling-means 12 to be screwed into the axel accepting aperture 142 c (as illustrated in FIG. 14 d ) of rear wheel 142 which is situated on top of basic unit 10 to hold basic unit 10 securely in its place as a sun umbrella. Again, in mirror imagine and thus not shown, there is an identical support on the other side of the device. First shaft 119 a also serves to keep first inner tube 55 a fixed to water disc-cycle 150 . A second support for basic disc 10 sun roof is provided by second shaft 119 b where first end of second shaft 119 b is supported in coupling connector aperture 132 b that is fixed about rod shaped connector means 132 a while second end of second shaft 119 b is positioned through the apertures of a second coupling cup 12 to provide support for basic disc 10 . Securely tucked in between and supported by second shaft 119 b and first inner tube 55 a is second inner tube 55 b, which is also kept securely related to the cycle by rotable shaft 107 that is connected to seating part 105 . Only the rearward half of second inner tube 55 b is shown so as not to obscure the relationship between second inner tube 55 b and the cycle parts. Hidden from view in this figure, is third inner tube that is a mirror image of first inner tube 55 a which also provides support for the opposite side of basic disc 10 .
[0156] FIG. 16 a is a top plan view and FIG. 16 b is a side plan view illustrating yet another style coupler-unit of this invention. Coupler-unit 160 serves as a bi-coupler having first coupler 12 on a first end of body part 165 and second coupler 12 on a second end of body part 165 . Coupler-unit 160 also serves as a means for making snow or ice cube-like toys. Body part 165 of coupler-unit 160 is provided with a plurality of casting impressions 166 that can be filled with snow or water. In the example illustrated in FIG. 16 a the impressions are of a penguin, but they can be of anything desired. Once the snow or water sets or freezes in the cast to form a set of molded impression toys, the molded toys are removed from the casts. The toys can be used in a multitude of ways. One way is for children to throw the toys down a snowy hill to see who can retrieve the largest number of toys as they slide down the hill on their coupleable sled, for example. The toys may be used to play catch, for juggling, or to throw through coupler openings, to give just a few more examples. The toys of this invention are designed to allow and encourage children to use their imaginations.
[0157] The foregoing description, for purposes of explanation, uses specific and defined nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the invention. Thus, the foregoing description of the specific embodiment is presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. Those skilled in the art will recognize that many changes may be made to the features, embodiments, and methods of making the embodiments of the invention described herein without departing from the spirit and scope of the invention. Furthermore, the present invention is not limited to the described methods, embodiments, features or combinations of features but include all the variation, methods, modifications, and combinations of features within the scope of the appended claims. The invention is limited only by the claims.
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A multiple use, light weight, cost-effective, indoor and all-weather outdoor construction toy for stimulating children's imaginations and encouraging physical activity comprises a basic modular unit with open ended cup-like coupling-means on its perimeter for male to female coupling and decoupling to other couple-able units, is described. The coupling-means may be molded as an integral part forming one seamless basic unit. The open bottom end of the coupling means provides for coupling, the open top end prevents the buildup of snow inside the coupling unit. Coupling can be achieved via coupling-means on basic units to each other or through the use of accessory independent coupler-units. The basic unit of the modular toy may be in the form of a saucer, disc, an oval, or in a rectilinear-shape for use as a sled, skiing device, a flotation device, or as fort building modules. Additional accessory parts include skis and inner-tubes, for example.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to formulations of cathepsin K inhibitors.
[0002] A variety of cathepsin K inhibitors have been disclosed for the treatment of various disorders related to cathepsin K functioning, including osteoporosis, glucocorticoid induced osteoporosis, Paget's disease, abnormally increased bone turn over, tooth loss, bone fractures, rheumatoid arthritis, osteoarthritis, periprosthetic osteolysis, osteogenesis imperfecta, atherosclerosis, obesity, glaucoma, chronic obstructive pulmonary disease and cancer including metastatic bone disease, hypercalcemia of malignancy, and multiple myeloma. Representative examples of cathepsin K inhibitors include those disclosed in International Publication WO03/075836, which published on Sep. 18, 2003, to Merck & Co., Inc. & Axys Pharmaceuticals, which is hereby incorporated by reference in its entirety.
[0003] Cathepsin K inhibitors can be formulated for oral dosing as tablets, by using a direct compression, wet granulation or roller compaction method. Similarly, cathepsin K inhibitors can be formulated for oral dosing as gelatin capsules, being a liquid in a soft capsule, or dry powder or semi-solid in a hard capsule. In addition, cathepsin K inhibitors can be formulated for intravenous dosing.
[0004] The formulations of the instant invention have advantages over other formulations of cathepsin K inhibitors. Specifically, the formulations of the instant invention significantly improve the absorption of the cathepsin K inhibitor. The formulations of the instant invention also improve the bioavailability of the cathepsin K inhibitor and reduce the variability in exposure. Exposure can vary due to many factors, including whether the cathepsin K inhibitor is taken with or without food.
SUMMARY OF THE INVENTION
[0005] The instant invention relates to pharmaceutical compositions containing cathespin K inhibitors. The cathepsin K inhibitor solid dispersion formulations of the present invention are made by spray drying or hot melt extrusion processes. The cathepsin K inhibitor is combined with a polymer, thus forming an amorphous system after spray drying. The spray dried amorphous systems are made by combining 10-20% of the cathepsin K inhibitor with 80-90% polymer. The amorphous system is then combined with excipients to form tablets, or combined with water to form a suspension. Also disclosed are processes for making said pharmaceutical compositions.
DETAILED DESCRIPTION OF THE INVENTION
[0006] The cathepsin K inhibitor solid dispersion formulations of the present invention are made by spray drying or hot melt extrusion processes. The cathepsin K inhibitor is combined with a polymer, thus forming an amorphous system after spray drying. The spray dried amorphous systems are made by combining 10-20% of the cathepsin K inhibitor with 80-90% polymer. The amorphous system is then combined with excipients to form tablets, or combined with water to form a suspension.
[0007] A particularly effective cathepsin K inhibitor is N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide,
[0000]
[0000] which can be prepared by procedures described in: International Publication WO03/075836, which published on Sep. 18, 2003, to Merck & Co., Inc. & Axys Pharmaceuticals; International Publication WO2006/017455, which published on Feb. 16, 2006, to Merck & Co., Inc.; U.S. Publication US2006-0052642, which published on Mar. 9, 2006; U.S. Publication US2005-0234128, which published on Oct. 20, 2005, to Merck & Co., Inc.; all of which are hereby incorporated by reference in their entirety. This compound is also known by its generic name, odanacatib.
[0008] The invention contemplates the use of any pharmaceutically acceptable fillers/compression aids, disintegrants, super-disintegrants, lubricants, binders, surfactants, film coatings, and solvents. Examples of these components are set forth below and are described in more detail in the Handbook of Pharmaceutical Excipients, Second Edition, Ed. A. Wade and P. J. Weller, 1994, The Pharmaceutical Press, London, England.
[0009] The instant invention comprises a pharmaceutical composition comprising from about 1% to 95% by weight of an amorphous cathepsin K inhibitor system, or a pharmaceutically acceptable salt thereof, and from about 5% to 99% by weight of excipients comprising a diluent, a glidant, a lubricant, a surfactant and a disintegrant. In a class of the instant invention, is a pharmaceutical composition comprising from about 44% to 57% by weight of an amorphous cathepsin K inhibitor system, or a pharmaceutically acceptable salt thereof, and from about 43% to 66% by weight of excipients comprising a diluent, a glidant, a lubricant, a surfactant and a disintegrant. In a class of the instant invention, is a pharmaceutical composition comprising about 50.0% by weight of an amorphous cathepsin K inhibitor system, or a pharmaceutically acceptable salt thereof, and about 50.0% by weight of excipients comprising a diluent, a polymer, a glidant, a lubricant, a surfactant and a disintegrant.
[0010] In an embodiment of the invention, the amorphous cathepsin K inhibitor system comprises a cathepsin K inhibitor and a polymer. Examples of the amorphous cathepsin K inhibitor systems of the instant invention include the spray dried material and the hot melt extrusion material.
[0011] In an embodiment of the invention, the cathepsin K inhibitor is N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide, or a pharmaceutically acceptable salt thereof.
[0012] In an embodiment of the invention, the polymer is hydroxypropyl methylcellulose acetate succinate (abbreviated as “HPMCAS”), copovidone (for example, Kollidon VA64), cellulose acetate phthalate, cellulose acetate succinate, methylcellulose phthalate, ethylhydroxycellulose phthalate, polyvinylacetatephthalate, polyvinylbutyrate acetate, vinyl acetate-maleic anhydride copolymer, styrene-maleic mono-ester copolymer, methyl acrylate-methacrylic acid copolymer, methacrylate-methacrylic or acid-octyl acrylate copolymer. The HPMCAS can be selected from HPMCAS-HF, HPMCAS-MF or HPMCAS-LF. HPMCAS-HF has an acetyl content of 10.0-14.0%, a succinoyl content of 4.0-8.0%, a methoxyl content of 22.0-26.0% and a hydroxypropoxyl content of 6.0-10.0%, with an average particle size of not more than 10 μm (available from ShinEtsu). HPMCAS-MF has an acetyl content of 7.0-11.0%, a succinoyl content of 10.0-14.0%, a methoxyl content of 21.0-25.0% and a hydroxypropoxyl content of 5.0-9.0%, with an average particle size of not more than 10 μm (available from ShinEtsu). HPMCAS-LF has an acetyl content of 5.0-9.0%, a succinoyl content of 14.0-18.0%, a methoxyl content of 20.0-24.0% and a hydroxypropoxyl content of 5.0-9.0%, with an average particle size of not more than 10 μm (available from ShinEtsu). In a class of the invention, the polymer is HPMCAS-HF.
[0013] In an embodiment of the invention, the amorphous cathepsin K inhibitor system comprises 10-20% of the cathepsin K inhibitor and 80-90% polymer. In a class of the invention, the amorphous cathepsin K inhibitor system comprises 10% of the cathepsin K inhibitor and 90% polymer. In another class of the invention, the amorphous cathepsin K inhibitor system comprises 15% of the cathepsin K inhibitor and 85% polymer. In another class of the invention, the amorphous cathepsin K inhibitor system comprises 20% of the cathepsin K inhibitor and 80% polymer.
[0014] In an embodiment of the invention, the cathepsin K inhibitor comprises 5.0 to 8.334% of the total tablet formulation. In a class of the invention, the cathepsin K inhibitor comprises 5.0% of the total tablet formulation. In another class of the invention, the cathepsin K inhibitor comprises 6.667% of the total tablet formulation. In another class of the invention, the cathepsin K inhibitor comprises 6.675% of the total tablet formulation. In another class of the invention, the cathepsin K inhibitor comprises 7.5% of the total tablet formulation.
[0015] In an embodiment of the invention, the diluents are selected from the group consisting of spray-dried lactose, lactose anhydrous, lactose monohydrate, mannitol, microcrystalline cellulose, calcium phosphate, calcium carbonate, magnesium carbonate and starch. In a class of the embodiment, the diluent is spray-dried lactose.
[0016] In an embodiment of the invention, the glidant, or flow aid, is silicone dioxide, colloidal silica, talc or starch. In a class of the invention, the glidant is silicone dioxide.
[0017] In an embodiment of the invention, the lubricant is magnesium stearate, stearic acid or sodium stearyl fumerate. In a class of the embodiment, the lubricant is magnesium stearate.
[0018] In an embodiment of the invention, the surfactant is sodium laurel sulfate, ammonium lauryl sulfate, another alkyl sulfate salt or poloxamer.
[0019] In an embodiment of the invention the disintegrant is croscarmellose sodium, starch, crospovidone, sodium starch glycolate or any mixtures thereof. In a class of the embodiment, the disintegrant is croscarmellose sodium.
[0020] The instant invention further comprises a method of improving the absorption of a cathepsin K inhibitor by combining the cathepsin K inhibitor with a polymer to form an amorphous system.
[0021] In an embodiment of the invention, the cathepsin K inhibitor is N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide, and the polymer is HPMCAS-HF.
[0022] The instant invention further comprises a method of reducing a food effect observed when dosing a cathepsin K inhibitor by combining the cathepsin K inhibitor with a polymer to form an amorphous system. In an embodiment of the invention, the cathepsin K inhibitor is N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide, and the polymer is HPMCAS-HF.
[0023] The instant invention further comprises a method of reducing variation in absorption observed when dosing a cathepsin K inhibitor by combining the cathepsin K inhibitor with a polymer to form an amorphous system. In an embodiment of the invention, the cathepsin K inhibitor is N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide, and the polymer is HPMCAS-HF.
[0024] The pharmaceutical tablet compositions of the present invention may also contain one or more additional formulation ingredients that may be selected from a wide variety of excipients known in the pharmaceutical formulation art. According to the desired properties of the tablet, any number of ingredients may be selected, alone or in combination, based upon their known uses in preparing tablet compositions. Such ingredients include, but are not limited to, diluents, binders, compression aids, disintegrants, lubricants, glidants, stabilizers (such as dessicating amorphous silica), flavors, flavor enhancers, sweeteners, preservatives, colorants and coatings.
[0025] The term “tablet” as used herein is intended to encompass compressed pharmaceutical dosage formulations of all shapes and sizes, whether uncoated or coated. Substances which may be used for coating include hydroxypropylmethylcellulose, hydroxypropylcellulose, titanium dioxide, talc, sweeteners and colorants.
[0026] The pharmaceutical compositions of the present invention are useful in the therapeutic or prophylactic treatment of disorders associated with cathpesin K functioning. Such disorders include: osteoporosis, glucocorticoid induced osteoporosis, Paget's disease, abnormal bone disease, tooth loss, bone fractures, rheumatoid arthritis, osteoarthritis, periprosthetic osteolysis, osteogenesis imperfecta, atherosclerosis, obesity, glaucoma, chronic obstructive pulmonary disease and cancer, including metastatic bone disease, hypercalcemia of malignancy, and multiple myeloma.
[0027] The following examples are given for the purpose of illustrating the present invention and shall not be construed as being limitations on the scope of the invention.
Example 1
Preparation of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (15% Drug Load in Spray Dried Material, 7.5% Drug Load in the Tablet Formulation)
[0028]
[0000]
Ingredient
[%]
Amount (mg)/tablet
15% N 1 -(1-cyanocyclopropyl)-4-
50.0
333.33
fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-
[4′-(methylsulfonyl)-1,1′-
biphenyl-4-yl]ethyl}-L-
leucinamide
85% HPMC-AS-HF
Lactose, spray dried
45.5
303.33
Croscarmellose sodium
3.0
20.00
Cab-o-sil
0.5
3.33
Magnesium stearate
1.0
6.67
% Total
100.0
666.67
[0029] The tablets were prepared by a dry granulation process. The N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide is combined with HPMC-AS-HF to form the spray dried material. The spray dried material was then blended with lactose, Croscarmelose sodium, cab-O-Sil and ½ of magnesium stearate and then dry granulated using a roller compaction equipment. The ribbon from the compaction was milled through a 1 mm screen. The milled granulation was blended for five minutes with the remaining of magnesium stearate. The 50 mg tablets were prepared using a tablet machine.
Example 2
Preparation of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (15% Drug Load in Spray Dried Material, 6.667% Drug Load in the Tablet Formulation)
[0030]
[0000]
Ingredient
[%]
Amount (mg)/tablet
15% N 1 -(1-cyanocyclopropyl)-4-
44.44
333.33
fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-
[4′-(methylsulfonyl)-1,1′-
biphenyl-4-yl]ethyl}-L-
leucinamide
85% HPMCAS-HF
Lactose, spray dried
45.31
339.79
Croscarmellose sodium
6.00
45.00
SLS
2.00
15.00
Cab-o-Sil
1.00
7.50
Magnesium stearate
1.25
9.38
% Total
100.0
750.00
[0031] The tablets were prepared by a dry granulation process. The N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide is combined with HPMCAS-HF to form the spray dried material. The spray dried material was then blended with lactose, Croscarmelose sodium, sodium laurel sulfate, cab-O-Sil and ½ of magnesium stearate and then dry granulated using a roller compaction equipment. The ribbon from the compaction was milled through a 1 mm screen. The milled granulation was blended for five minutes with the remaining of magnesium stearate. The 50 mg tablets were prepared using a tablet machine.
Example 3
Preparation of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (10% Drug Load in Spray Dried Material, 5% Drug Load in the Tablet Formulation)
[0032]
[0000]
Ingredient
[%]
Amount (mg)/tablet
10% N 1 -(1-cyanocyclopropyl)-4-
50.0
500.00
fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-
[4′-(methylsulfonyl)-1,1′-
biphenyl-4-yl]ethyl}-L-
leucinamide
90% HPMCAS-HF
Lactose, spray dried
20.125
201.25
Avicel PH 102
20.125
201.25
Croscarmellose sodium
6.0
60.00
SLS
2.0
20.00
Cab-o-Sil
0.75
7.50
Magnesium stearate
1.0
10.00
% Total
100.0
1000
[0033] The tablets were prepared by a dry granulation process. The N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide is combined with/ HPMCAS-HF to form the spray dried material. The spray dried material was then blended with lactose, Croscarmelose sodium, cab-O-Sil and ½ of magnesium stearate and then dry granulated using a roller compaction equipment. The ribbon from the compaction was milled through a 1 mm screen. The milled granulation was blended for five minutes with the remaining of magnesium stearate. The 50 mg tablets were prepared using a tablet machine.
Example 4
Preparation of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (15% Drug Load in Hot Melt Extrusion Material, 6.675% Drug Load in the Tablet Formulation)
[0034]
[0000]
Ingredient
[%]
Amount (mg)/tablet
15% N 1 -(1-cyanocyclopropyl)-4-
44.5
333.33
fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-
[4′-(methylsulfonyl)-1,1′-
biphenyl-4-yl]ethyl}-L-
leucinamide
10% Cremophor EL
75% Kollidon VA64
Lactose, spray dried
12.0
89.89
Avicel PH 102
36.0
269.67
Croscarmellose sodium
6.0
44.94
Cab-o-Sil
0.5
3.75
Magnesium stearate
1.0
7.49
% Total
100.0
750.00
[0035] The tablets were prepared by a dry granulation process. The N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide, Cremophor EL and Kollidon VA64 were combined to form the hot melt extrudet. The hot melt extrudet was then blended with lactose, Avicel PH102, Croscarmelose sodium, cab-O-Sil and ½ of magnesium stearate and then dry granulated using a roller compaction equipment. The ribbon from the compaction was milled through a 1 mm screen. The milled granulation was blended for five minutes with the remaining of magnesium stearate. The 50 mg tablets were prepared using a tablet machine.
Example 5
Preparation of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (15% Drug Load in Spray Dried Material, 8.334% Total Drug Load in the Tablet Formulation)
[0036]
[0000]
Ingredient
[%]
Amount (mg)/tablet
15% N 1 -(1-cyanocyclopropyl)-4-
55.56
333.33
fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-
[4′-(methylsulfonyl)-1,1′-
biphenyl-4-yl]ethyl}-L-
leucinamide
85% HPMCAS-HF
Lactose, spray dried
20.22
121.33
Avicel PH 102
20.22
121.33
Croscarmellose sodium
3.00
18.00
Magnesium stearate
1.00
6.00
% Total
100.0
600.00
[0037] The tablets were prepared by a dry granulation process. The N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide was combined with HPMC-AS-HF to form the spray dried material. The spray dried material was then blended with lactose, Avicel PH102, Croscarmelose sodium, cab-O-Sil and ½ of magnesium stearate and then dry granulated using a roller compaction equipment. The ribbon from the compaction was milled through a 1 mm screen. The milled granulation was blended for five minutes with the remaining of magnesium stearate. The 50 mg tablets were prepared using a tablet machine.
Example 6
Preparation of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (15% Drug Load in Spray Dried Material, 8.334% Total Drug Load)
[0038]
[0000]
Ingredient
[%]
Amount (mg)/tablet
15% N 1 -(1-cyanocyclopropyl)-4-
55.56
333.33
fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-
[4′-(methylsulfonyl)-1,1′-
biphenyl-4-yl]ethyl}-L-
leucinamide
85% HPMCAS-HF
Lactose, spray dried
39.94
239.66
Croscarmellose sodium
3.00
18.00
Cab-o-sil
0.50
3.00
Magnesium stearate
1.00
6.00
% Total
100.0
600.00
[0039] The tablets were prepared by a dry granulation process. The N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide was combined with HPMC-AS-HF to form the spray dried material. The spray dried material was then blended with lactose, Croscarmelose sodium, cab-O-Sil and ½ of magnesium stearate and then dry granulated using a roller compaction equipment. The ribbon from the compaction was milled through a 1 mm screen. The milled granulation was blended for five minutes with the remaining of magnesium stearate. The 50 mg tablets were prepared using a tablet machine.
Example 7
Preparation of Suspension of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (30 Mg/G)
[0040]
[0000]
Component
Amount
15% N 1 -(1-cyanocyclopropyl)-4-
15.0 g
fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-
(methylsulfonyl)-1,1′-biphenyl-4-
yl]ethyl}-L-leucinamide
85% HPMCAS-HF
Water
60.0 g
Suspension Preparation:
[0000]
1. Weigh 15.0 g of N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide and HPMCAS-HF in a defoamer container (size: 150 or 250 ml).
2. Add 60.0 g of water into the container; Shake gently to wet all the SD material.
3. Mix for 5 min using a defoamer and defoam for additional 5 min; Make sure a homogeneous suspension is formed.
Example 8
Preparation of Suspension of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (20 Mg/G)
[0044]
[0000]
Component
Amount
15% N 1 -(1-cyanocyclopropyl)-4-
10.0 g
fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-
(methylsulfonyl)-1,1′-biphenyl-4-
yl]ethyl}-L-leucinamide
85% HPMCAS-HF
Water
65.0 g
Suspension Preparation:
[0000]
1. Weigh 10.0 g of N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide and HPMCAS-HF in a defoamer container (size: 150 or 250 ml).
2. Add 65.0 g of water into the container; Shake gently to wet all the SD material.
3. Mix for 5 min using a defoamer and defoam for additional 5 min; Make sure a homogeneous suspension is formed.
Example 9
Preparation of Suspension of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide (2.0 Mg/G)
[0048]
[0000]
Component
Amount
15% N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-
1.00 g
2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-
4-yl]ethyl}-L-leucinamide
85% HPMCAS-HF
Water
74.0 g
Suspension Preparation:
[0000]
1. Weigh 1.00 g of N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide and HPMCAS-HF in a defoamer container (size: 150 or 250 ml).
2. Add 74.0 g of water into the container; Shake gently to wet all the SD material.
3. Mix for 5 min using a defoamer and defoam for additional 5 min; Make sure a homogeneous suspension is formed.
Example 10
Preparation of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide 50 Mg Tablets
[0052]
[0000]
%
Ingredient
wt./wt.
Mg/Tablet
N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-
12.5
50.00
2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-
biphenyl-4-yl]ethyl}-L-leucinamide
Microcrystalline Cellulose
40
160.00
Lactose Monohydrate
40
160.000
Croscarmellose Sodium
4
16.00
Hydroxypropyl cellulose
3
12.00
Magnesium Stearate
0.5
2.00
Purified Water*
[35]
[140.00]
Total
100
400.00
*removed during the during process
[0053] N 1 -(1-cyanocyclopropyl)-4-fluoro-N 2 -{(1S)-2,2,2-trifluoro-1-[4′-(methylsulfonyl)-1,1′-biphenyl-4-yl]ethyl}-L-leucinamide, 4% (wt./wt.) croscarmellose sodium, and a 1:1 (wt./wt.) mixture of microcrystalline cellulose and lactose monohydrate are dry blended in a high shear mixer, and then a 3% (wt./wt.) hydroxypropyl cellulose solution is sprayed onto the mixing powders to effect granulation. The wet granulate is dried in a fluid bed dryer, the dried granulate is then milled, and finally lubricated with 0.5% (wt./wt.) magnesium stearate in a blender. Tablets were then compressed on a rotary tablet press.
Example 11
Mean (Se) Pk Parameters after Oral Administration of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide Solid Tablets (10 Mg Dose/Animal) in Fasted Male Beagle Dogs
[0054]
[0000]
Dose
AUC 0-72hr
AUC 0-24hr
C max
T max
Formulation
(mg)
(μM*hr)
(μM *hr)
(μM)
(hr)
Example 10
10
N/A
7.3 (3.6)
0.46 (0.14)
4 (0.5, 4)
Example 2
10
N/A
59.6 (5.2)
3.93 (0.10)
4 (4, 4)
Example 3
10
178.0 (38.2)
70.6 (16.2)
4.0 (0.8)
2 (2, 8)
Example 4
10
41.8 (11.8)
16.8 (4.0)
0.9 (0.2)
8 (8, 24)
[0055] Animal studies in beagle dogs were conducted to evaluate the formulations. In general, the formulations containing the spray dried material (Examples 2 and 3) provided ˜8-10 fold higher exposures compared to the formulation that does not contain the spray dried material or hot melt extrusion and ˜5 folds higher than the hot melt extrusion (Example 4). Similarly, the formulation containing the hot melt extrusion material (Example 4) increased the exposure by about 2.3 folds higher exposure compared to the standard formulation (Example 10).
Example 12
Mean (Se) Pk Parameters after Oral Administration of N 1 -(1-Cyanocyclopropyl)-4-Fluoro-N 2 -{(1S)-2,2,2-Trifluoro-1-[4′-(Methylsulfonyl)-1,1′-Biphenyl-4-Yl]Ethyl}-L-Leucinamide Solid Tablets (10 Mg Dose/Animal) in Fasted/Fed Male Beagle Dogs
[0056]
[0000]
Feeding
Conditions
(10 mg
AUC 0-24hr
C max
T max
Formulation
dose)
(μM *hr)
(μM)
(hr)
AUC Fed/Fasted
Example 10
Fasted
7.3 (3.6)
0.46
4 (0.5, 4)
4.3
(0.14)
Fed
31.4 (6.1)
1.77
8 (8, 8)
(high fat)
(0.40)
Example 2
Fasted
59.6 (5.2)
3.93
4 (4, 4)
1.2
(0.10)
Fed
73.0 (8.3)
4.27
6 (6, 8)
(high fat)
(0.41)
[0057] A significant food effect was observed with the formulation that does not contain the spray dried material. The formulation containing the spray dried material (Example 2) helped to minimize the variability in exposure.
|
The instant invention relates to pharmaceutical compositions containing cathespin K inhibitors. Also disclosed are processes for making said pharmaceutical compositions.
| 8
|
FIELD OF INVENTION
The present invention relates to spring assemblies in which a coiled strip spring member, optionally consisting of a plurality of spring leaves is supported, typically at one end, for reverse winding (i.e. winding against its coiling direction) on means defining an arcuate path of support and at its other end forms a coil and is positioned against an abutment member which forces unwinding of said coil as the spring is reverse wound over the means defining the arcuate path of support in use.
BACKGROUND TO THE INVENTION
Spring assemblies of this general type are disclosed in U.S. Pat. No. 3,047,280. Also described is their use in connection with hinge mechanisms such as for instance the hinges supporting the tail gate, boot lid (or trunk lid) or bonnet (or hood) of an automobile.
Automobile boot lids and tail gates are conventionally mounted on hinges which are biassed to the open position by gas struts. As compared to springs, gas struts have a number of known disadvantages. A major problem is that the force which they exert varies substantially according to the ambient temperature.
Springs do not suffer from this disadvantage but previous proposals for the use of springs in supporting components of this nature have also encountered practical difficulties. Helical coil springs and torsion bars have been proposed but these often encroach into the usable space of the luggage storage area to a significant extent. The type of coil strip spring assembly described in U.S. Pat. No. 3,047,280 once installed avoids all these past disadvantages in that it is compact and insensitive to variations of ambient temperature.
However, despite the fact the use of these types of spring assemblies in this particular context was proposed as long ago as 1962 in U.S. Pat. No. 3,047,280 they have not been used to any significant extent in automobile manufacture.
The process of installation of a spring of this type into an automobile boot by way of example to construct such an installation would involve the attachment to one component of the hinge in situ in the boot of an arcuate support member such as part of a drum to which is secured one end of a multileaf coiled strip spring. An abutment member will be provided on another component of the hinge moveable with respect to the location for the arcuate support member and it will be necessary for the spring coil to be extended and positioned over the abutment member. For a spring capable of supporting an automobile boot lid or tail gate this will involve the application of very substantial amounts of force to the spring whilst it is in position in a physically confined and obstructed location. It is difficult to introduce into the space concerned the machinery necessary to achieve this and there is also the risk that a spring may escape as it is being extended and cause damage to the vehicle or risk of injury to the assembly workers as it lashes back.
Furthermore, it is not appropriate for springs of this nature to be painted because the paint will inevitably flake as the spring is repeatedly flexed in use. Accordingly, such an installation has to be carried out after the vehicle itself has been painted and there is thereby an extra danger of damage to the paint work of the vehicle during the spring installation. These practical difficulties have effectively caused the use of this type of spring to be abandoned or ignored and have caused the industry to put up with difficulties of the alternatives discussed above.
BRIEF DESCRIPTION OF THE INVENTION
We have now developed a design for a spring assembly of the kind with which the invention is generally concerned which avoids these difficulties.
The present invention provides in a first aspect a spring assembly comprising a coiled strip spring member, a first support member having mounted thereon means defining an arcuate path of support for the spring member such that the spring member may be wound against its natural coiling direction by rotation of said means through a part circle and a second support member carrying an abutment member against which said spring runs so as to force unwinding of said spring coil which said spring is reverse wound over the arcuate path of support, and means interconnecting said first and second support members such as to prevent relative movement thereof which would allow said spring to coil further.
The first and second support members may for instance each comprise a base plate and said means interconnecting said support members may interconnect said base plates.
Preferably, one of said support member base plates has at least one guidance slot therein and the other of said support member base plates carries a projection running in said guidance slot, said relative movement of the support members to allow further coiling of said spring about said abutment member being prevented by said projection reaching a limiting position in said guidance slot.
Preferably there are at least two said guidance slots each co-operating with a respective said projection.
Alternative means for interconnecting the support members so as to prevent relative movement thereof which would allow said spring to coil further can be used. For instance, a first and a second base plate may each be provided with respective abutment members which bear against one another to prevent movement of the base plates with respect to one another in a sense which would allow coiling of the spring.
As a further variant of this such base plates may be connected by frangible links such as frangible rivets or pins which hold the base plates together in a desired position until such time as the rivets are broken by a user putting the assembly into use. Equally, they may be connected by pins which are driven out by a user once the assembly is installed in position as described hereafter.
Preferably, each said base plate is provided with a respective cover member for defining with its respective base plate a housing or enclosure for a respective part of said spring member.
The means defining an arcuate path of support for the spring member may have a cylindrical or part cylindrical support surface and may for instance be a curved plate member. Preferably, an end portion of the spring member is attached to the means defining the arcuate path of support, normally towards one end thereof. Whilst the means defining the arcuate path of support preferably defines a continuous arcuate path of support, it is within the scope of the invention to use a discontinuous support means such a plurality of support posts arranged around an arcuate path.
Optionally, more than one abutment member is provided and optionally more than one coiled spring member is provided. For instance, a plurality of coiled spring members, e.g. two, may each be connected at one end to a common location on means defining an arcuate path of support such as an arcuate plate and may then each be lodged against a respective abutment member which forces unwinding of its respective spring coil as the arcuate path of support is rotated with respect to the abutment member.
Preferably, the coil formed by the strip spring member is arranged around the abutment member but alternatively it can be arranged to lie beyond the abutment member.
In an alternative aspect, the invention provides a spring assembly comprising a coiled strip spring member, means defining an arcuate path support for said spring member upon which said spring member may be wound against its natural coiling direction by rotation of said path defining means through a part circle, and an abutment member radially spaced from said path defining means against which said spring member is supported so as to force unwinding of said spring coil as the spring member is reverse wound onto said path defining means, said spring member, said path defining means and said abutment member being contained within housing means which permits limited planetary motion of said abutment member with respect to said path defining means to tension said spring member by reverse winding said spring member over said path defining means.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further illustrated by the following description of preferred embodiments thereof with reference to the accompanying drawings in which:
FIG. 1 shows an exploded view of a spring assembly according to the invention about to be mounted on a hinge for a vehicle boot lid,
FIG. 2 shows a second embodiment in plan view; and
FIG. 3 shows a third embodiment in exploded perspective view.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The spring assembly illustrated in FIG. 1 comprises a first support member in the form of a base plate 10 which has a rectangular aperture therein over which is fixed a rectangular collar 12 forming a non-rotatable mounting for receiving a rectangular post 14 associated with the hinge assembly to which it is to be fitted. Mounted on the upper surface of the base plate 10 is an arcuate metal plate 16 in the form of a half circle firmly connected by its edge, e.g. by welding, to the base plate 10. A second base plate 18 has an abutment member in the form of hollow post 20 mounted over a non-circular aperture therein (e.g. a square aperture) for receiving in a non-rotatable manner a post 22 of corresponding section carried by a second component of the hinge assembly to be described hereafter. The hollow post 20 is provided with upper and lower flanges 24 spaced apart along the length of the post 20. Alternatively, a flanged bobbin may be fitted over the exterior of a plain hollow post 20, to rotate thereon. The base plate 10 overlies the base plate 18 and the two are connected together as follows. The base plate 10 has a pair of slots 26, 28. Slot 26 extend from one edge of the base plate 10 and has an opposite blind end. Slot 28 is positioned in a projecting lug 30 on the base plate 10 which has a surface facing in the same direction as that edge of the base plate 10 on to which the slot 26 opens. Slot 28 opens from that edge of the lug 30 and extends to a blind opposite end. A pair of connecting projections 32 extends from the base plate 18 upwards through the slots 26, 28 and are provided with head formations at their free ends overlying the base plate 10. A multi-laminate metal coiled strip spring member 34 is attached at one end to the arcuate plate 16 and extends over a portion of the arcuate plate 16 and thence to the abutment member 20 about which it freely coils. The spring member is attached to the arcuate plate 16 by a rivet 36 or any equivalent fixing such as a high tensile bolt or a nut and bolt assembly and over its entire length is predisposed to form a coil by bending in a sense opposite to that in which it is bent to follow the line of curvature of the arcuate plate 16. In the position illustrated therefore the spring member 34 is under tension and this tension serves to force the projections 32 towards to the blind ends of the slots 26, 28 in which they locate but further movement of the base plates to relieve the tension in the spring 34 by allowing it to unwind from the arcuate plate 16 is prevented by the slots 26, 28 and the projections 32 located against the blind ends thereof.
A pair of cover members 38, 40 are provided which clip over the respective base plates 18 and 10 and which each comprise a top wall and a depending substantially D-shaped skirt wall. With the base plates 10 and 18, the cover members 38 and 40 define a housing enclosing the spring member 34, the abutment 20 and the arcuate plate 16.
A hinge assembly to which the spring assembly described above is to be fitted is provided in the boot of an automobile and consists of a first member 42 fixed to the body of the automobile having a projecting arm upon which is positioned the mounting post 14 and a second member in the form of an arm 44 which is hinged a hinge location 46 to the first component 42 and which at its opposite end will be joined to the boot lid to be supported. The arm 44 carries on a bracket the mounting post 22 engageable in the bore within the hollow post 20 constituting the abutment member of the spring assembly.
To install the spring assembly on the hinge assembly all that is necessary is to first install the components of the hinge in the automobile boot, optionally with the boot lid in place, position the hinge components in the boot lid-raised position and fit the hollow posts 12 and 20 over the mounting posts 14 and 22. Closing the boot lid will then cause rotation of the abutment member 20 on its base plate 18 in a planetary manner about the arcuate plate 16 with the projections 32 leaving the slots 26 and 28 in which they are received. The spring will be further tensioned by further reverse winding over the arcuate support plate 16 providing counter balancing for the boot lid. When the boot lid is raised again, the projections 32 will reenter the slots 26 and 28 and the blind ends of those slots will eventually act as stops determining the extent of opening of the boot lid.
It will be appreciated that if the housing 38, 40 is paintable then this spring assembly may be installed prior to the spraying of the automobile. The housing assembly will protect the spring member 34 from being painted. The housing containing the spring member will thus be painted to match the car body, which is not possible using gas struts. It should further be appreciated that the mounting of the spring assembly on to the hinge assembly is an operation which can be conducted rapidly without the use of machinery and without any risk of the spring member 34 flying loose and causing damage. In use, the spring member is shielded from objects and from the users fingers when the boot is open, so conferring extra safety.
A further safety advantage compared to the form of installation shown in U.S. Pat. No. 3,047,280 is that if a vehicle owner or a mechanic tries to disassemble a hinge as shown therein he will be at risk of injury and at risk of causing damage as the spring will fly back with great vigour when released from the abutment which holds it. With the assembly described above this risk is removed and the two base plates can safely be removed from the hinge in the open position.
All of the disadvantages which have so far prevented the adoption of this otherwise advantageous manner of counter balancing vehicle components are therefore overcome.
The second embodiment shown in FIG. 2 is similar to that shown in FIG. 1 except that the base plate 110 is formed with an arcuate slot 128 and the base plate 118 is formed with an arcuate slot 126. A pin 132 on the base plate 118 runs in the arcuate slot 128 of the base plate 110 and a similar pin 132' depending from the underside of the base plate 110 runs in the arcuate slot 126 in base plate 118. The pins 132, 132' are captive in their slots and do not escape therefrom. Each has an enlarged head preventing separation of the plates along the axes of the pins 132, 132'. The spring assembly is shown in a position which would correspond to the open position of a vehicle boot lid supported by the spring. On closing the boot lid, the base plate 118 would be moved in the direction shown by the arrow so as to tension further the spring member 34 by reverse winding it about the arcuate plate 16.
In the third embodiment shown in FIG. 3, the base plate 210 has a pivoting arm 218 mounted thereto at a pivot 218 and the abutment 220 is positioned on the end of the arm 218. The hinge mounting includes a pivoting arm 44 hinged to a first component 42 of the hinge which bears an L-shaped plate 43 having a first and a second through holes 45, 47 therein. Clinch studs 232 depending from the underside of base plate 210 are received in the holes 45, 47 to mount the base plate 210 to the first component 42 of the hinge assembly.
A single cover 238 is mounted to the abutment 220 and extends to cover the arcuate plate 16 on the base plate 10.
The spring assembly is shown in the fully tensioned position, corresponding to the closed position of a car boot lid. As the spring assembly moves to the fully open position by pivoting in the direction indicated by the arrow, the leading edge of the swinging arm 218 comes to abut against the clinch stud 232 which limits its further movement in the unwinding direction. At this point, the spring assembly is removable and installable on the hinge assembly with the tension of the spring being supported on the clinch stud 232.
Many modifications and variations of the invention as described above are possible. For instance, in FIG. 1 the entry of the projections 32 into their slots 26, 28 may be arranged to provide a progressive cushioning and buffering action which will cushion the arrival of the boot lid into its fully open position. This might for instance be arranged by providing springs within the slots 26, 28 against which the projections 32 will bear as they run down the slots. Also such projections may operate a latch to hold the boot lid fully open.
A spring assembly of the type claimed can greatly facilitate the wiring of components mounted on the boot lid such as lamps and sensor switches. To this end, a spring assembly according to the invention may be provided with a first electrical connector or set of electrical connectors associated with the first support member and a second electrical connector or set of electrical connectors associated with the second support member and means providing electrical connection between said connectors or sets of connectors such as a wiring loom. This will enable wiring from boot lid components to be led to the spring assembly housing and connected to the first connector or set of connectors which are flexibly linked to the opposite connector or set of connectors which can be connected up to the main wiring harness of the vehicle.
It should be appreciated that the cover members 38, 40 in FIG. 1 and 138 in FIG. 3 are not necessary to permit easy installation of the illustrated spring assembly. They do however enhance its appearance, facilitate painting after spring installation and provide extra safety. Similar cover members can be provided in the assembly shown in FIG. 2.
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A spring assembly of the kind having a coiled strip spring member (34) supported at one end on an arcuate drum portion (16) about which it is reverse wound and coiled at its other end about an abutment (20) further includes a base plate (10) mounting the drum portion (16) and a second base plate (18) mounting the abutment (20), the base plates (10) and (18) being interconnected by pins (32) attached to base plate (18) running in slots (26, 28) provided on base plate (10) so as to prevent relative movement of the base plates which would allow the spring to coil further about the abutment (20). The base plate (10) is provided with a cover (40) with which it forms a housing portion and the base plate (18) is provided with a cover (38) with which it forms a second housing portion. The assembly can be dropped on to support pins (14, 22) attached to respective halves (42, 44) of a hinge, e.g. of an automobile trunk or lid.
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[0001] CROSS REFERENCE TO RELATED APPLICATIONS
[0002] The present invention is a continuation of U.S. patent application Ser. No. 08/540,323, filed Oct. 6, 1995, now U.S. Pat. No. 6,371,254, the specification of which is hereby incorporated in its entirety.
FIELD OF THE INVENTION
[0003] The present invention relates generally to safety brakes for hydraulic jacks or rams. In particular the present invention relates to a hydraulic ram lifting elevator emergency arrestor using a lever and lock mechanism to provide braking action without permanently damaging or destroying the hydraulic ram.
BACKGROUND OF THE INVENTION
[0004] The present invention relates to a hydraulic ram arrestor using a lever lock type of mechanism which is activated by a pressure failure condition, down overspeed, or uncontrolled down motion. When activated, two lever acting brake arms are dropped into contact with the elevator ram, the resulting friction bringing the elevator to a sliding stop. There have been numerous brake systems developed for stopping hydraulic ram elevators during emergency situations. All of the prior art patents found were directed toward collets or brake shoes, that, during a hydraulic pressure failure, would drop down and wedge in between a fixed housing and the ram of the elevator. The friction generated by the downward motion of the ram in contact with the collet or brake shoe causes the collet or brake shoe to be driven downwardly, thereby wedging the ram to a halt. Empirical evidence indicates that the force necessary to stop an elevator using such a brake exceeds the elastic limit of the material used in commercial rams causing the ram to be deformed into an hourglass shape at the point where such brakes grip the ram. This type of damage to the ram cannot be repaired and instead, expensive and time consuming replacement is required to restore the elevator to working condition. The prior art patents also disclosed elevator brakes that have many moving parts, and are correspondingly complex. Additionally, the prior art devices appear relatively large and bulky. Size is an important consideration because there is often limited space into which to fit a braking device. Therefore, it is desirable for the brake to have a low profile, thereby facilitating installation in all present hydraulic elevators. As a specific example of a prior art design having the above mentioned short comings, Beath et al., U.S. Pat. No. 4,449,615 is a floor mounted lever-actuated wedge device. The many components in this design complicate it by comparison to the present invention. Beath uses collets, that, during a hydraulic pressure failure, drop down and wedge in between a fixed housing and the ram of the elevator. The friction generated by the downward motion of the ram in contact with the collets causes the collets to be driven downward, thereby wedging the ram to a halt. The force necessary to stop an elevator using the brake disclosed in Beath exceeds the elastic limit of the material used in commercial rams causing the ram to be deformed into an hourglass shape at the point where the collets grip the ram. Additionally, the above mentioned patent does not precisely show relation to the top of the cylinder and the bottom of the elevator. However, it appears too tall to fit most existing elevator systems. In light of the problems listed above and exemplified by U.S. Pat. No. 4,449,615, a new elevator brake is needed that can safely stop a fully loaded elevator without permanently damaging the ram.
[0005] The present invention, using an accretable metal or other adherent material to apply a braking force to the ram is a clear improvement over the prior art. Prototype testing has shown that copper bar formed to shape has yielded sufficiently high braking force, with and without the presence of oil on the surface of the ram. Several materials have been tested, and, to date, copper has been the best material for the purpose. The present invention is also comparatively simple and low in profile facilitating installation on current elevator designs.
SUMMARY OF THE INVENTION
[0006] The general object of the present invention is to provide a mechanism for arresting an elevator which can safely stop a filly loaded elevator without permanently damaging any part of the elevator.
[0007] It is another object of the present invention to provide an elevator arrestor that allows the elevator to be usable within a short period of time with little reset and repair necessary. Optimally, the reset and repair should be a relatively simple and inexpensive procedure.
[0008] It is a further object of the present invention to provide an arrestor that will fit within a small vertical space such that it can fit within the normal design parameters for hydraulic ram elevators, and may also be retrofit into existing hydraulic ram elevators.
[0009] It is yet another object of the present invention to provide a system that can be easily installed and requires very little down time in which the elevator is non-functional.
[0010] It is an additional object of the present invention to provide for an arresting system that is inexpensive to manufacture.
[0011] The present invention is a hydraulic safety arrestor for slowing and stopping a ram, jack or other cylinder type object. It utilizes two lever acting brake arms lined with an accretable metal as the friction material. When actuated, the brake arms contact the ram circumferentially to slow and stop the falling ram. The lining material is machined inside the brake arms to a diameter slightly less than the diameter of the ram. When actuated, the lining material contacts the ram with sufficient frictional force to stop the downward motion of the ram without permanent deformation of the ram. The rest of the mechanism is comprised of buttress members, pivot pins, and a base plate, mounted above a spacer ring. The spacer ring is the same diameter as the cylinder and is variable in length to raise the base plate and brake assembly above any bolts or other existing projections. Eyelets are welded to the existing cylinder to provide for secure mounting and correct alignment and realignment when the brake is removed and reinstalled.
[0012] The brake arms may be actuated mechanically by loss of hydraulic pressure, by an electronic signal from a hydraulic pressure detector, by down overspeed or by an uncontrolled down motion detector.
[0013] The force applied by the braking action is transferred from the brake arms through the base plate and spacer ring onto the circumferential area of the top of the main cylinder and any associated support structures. By monitoring the pressure and overspeed, the fall of the elevator can be limited to speeds with a maximum of less than twice the normal down speed, thus limiting the kinetic energy produced, by not allowing a free falling elevator. Therefore, the pit structure would absorb the energy without damage or permanent deformation, without any modifications to the pit structure.
[0014] These and other objects and advantages of the invention will no doubt occur to those skilled in the art upon reading and understanding the following detailed description along with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a side elevation view showing the brake and control components according to the invention.
[0016] [0016]FIG. 2 is the front elevation view showing the brake and control components according to the invention.
[0017] [0017]FIG. 3 is a sectional view showing the frictional contact, and locations of the packing in relation to the invention, as viewed along the line A-A in FIG. 4.
[0018] [0018]FIG. 4 is a plan view of the invention, as viewed along the line 1-1.
[0019] The term “accretable” is used in its conventional sense, meaning that the friction material is able to accrete to or to adhere to the surface of the ram.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The drawings show a safety brake system according to the present invention, indicated generally by the reference number 1 . Although the brake system 1 is applicable to many hydraulic ram or piston devices, it is described here in its preferred use on a hydraulic ram lifting elevator. References to “up”, “down”, “vertical”, “horizontal”, etc. should be understood to refer generally to the relative positions of the components of the illustrated device, which could be otherwise oriented or positioned for non-elevator applications. Further, although the term “hydraulic” is used, this invention could be used on any device with a similar configuration, i.e. a main cylinder which surrounds a second cylinder. References to “hydraulic” should be understood to refer generally to any pressure ram device including but not limited to hydraulic and pneumatic ram devices. In FIG. 1, a reciprocal piston or ram 3 is shown with brake system 1 installed on the existing main cylinder 5 . Spacer ring 7 rests upon the upper end of main cylinder 5 at 9 and is removably fixed to upper end of main cylinder 5 by any one of a number of known fastening means. In a preferred embodiment, the known fastening means comprises eyelets 11 fixed to the outside surface of main cylinder 5 and near the upper end 9 of main cylinder 5 . Each eyelet comprises a pair of flange 15 spaced a short distance apart, and flanges 17 on spacer ring 7 fit in between flange 15 of eyelets 11 . Flanges 17 and flange 15 have bolt holes 19 which are aligned to accept eyelet bolts 20 to fix spacer ring 7 to main cylinder 5 . In an alternate embodiment, eyelets 11 may comprise only a single flange. The advantage of using eyelets 11 is that any one of eyelets 11 can act as a pivot to rotate brake system 1 away from main cylinder 5 to allow access for servicing when eyelet bolts 20 are removed from the other eyelets 11 . Removal of all eyelet bolts would allow total removal of brake system 1 for major work. Eyelets 11 also allow for exact reattachment of the device assuring proper alignment.
[0021] Base plate 21 is fixed to the upper surface of spacer ring 7 at 23 . Buttress members 25 are fixed to base plate 21 on either side of brake arms 27 . In the preferred embodiment, brake arms 27 are hingably fixed to buttress members 25 by pivot bolts 29 allowing brake arms 27 to rotate into or out of contact with ram 3 .
[0022] In ready or standby position, brake arms 27 are raised 15 degrees from horizontal, allowing travel clearance of ram 3 , best seen in FIG. 2. Brake arms 27 are shaped having semicircular cut-outs 26 , best seen in FIG. 4, of diameter slightly larger than ram 3 , and having a friction material mounting surface 28 on the inside of cutouts 26 , best seen in FIG. 3. An accretable friction material 31 is fixed to the friction material mounting surfaces 28 of half circular cut-outs 26 of brake arms 27 . In a preferred embodiment the accretable material 31 is annealed copper, but other materials may be used. Annealed copper is preferred because, of the materials tested, it has the greatest tendency to adhere to the ram 3 . This maximizes the amount of friction between the ram 3 and the brake 20 lining 31 , which creates the greatest braking force with the least amount of damage/deformation of the ram 3 and the braking system 1 . The inside diameter of the accretable friction material 31 is slightly smaller than the outside diameter of the ram 3 .
[0023] This provides proper engagement with ram 3 to bring the elevator to a halt.
[0024] Although the preferred embodiment uses two brake arms 27 , a multiplicity of brake arms could be used. Each of the segments would form a section of the ring around the ram 3 .
[0025] These sections could be equal in size, or they could be disparate, if desired. Different sized sections could be advantageous in some situations, including where the configuration of the work space makes installation or maintenance easier if a certain portion of the brake system 1 is more articulated.
[0026] In an alternate brake arm embodiment, not shown, cutting bits or teeth may be fixed to the friction material mounting surface 28 of brake arms 27 in place of or in addition to accretable friction material 31 . In this alternate embodiment, braking is accomplished by the teeth biting into ram 3 . Unlike the hourglassing damage caused by the prior art, the type of damage caused by this alternate embodiment can be repaired by filling and filing the gouges.
[0027] Other systems for hingably fixing brake arms 27 to buttress members 25 are possible. In an alternate hinge embodiment, hinge bolts may be used. In the hinged bolt embodiment, not shown, the rear side of brake arms 27 opposite the semicircular cut-outs 26 are oriented against buttress members 25 rather than lying between them as in the preferred embodiment. Brake arms 27 are spaced from buttress members 25 a distance sufficient for brake arms 27 to be rotated upwardly 15 degrees from horizontal. A plurality of hinge bolts pass through holes in buttress member 25 into the rear edge of brake arms 27 and are threadably fixed thereto. Bending of the hinge bolts allows pivotal motion of brake arms 27 .
[0028] In another alternate hinge embodiment, also not shown, a slide hinge may be used. In this alternate embodiment, the side of brake arms 27 opposite the side nearest ram 3 are, again, oriented against buttress members 25 rather than lying between them. Buttress member 25 has a concave channel to partially receive the rear edge of brake arms 27 , and the rear edge of brake arm 27 is rounded to fit the concave surface of buttress members 25 . During pivotal movement of brake arms 27 the rounded rear edges of brake arms 27 slide within the concave surface of buttress member 25 .
[0029] [0029]FIG. 3 shows the brake system 1 in actuated position. Accretable friction material 31 is in contact circumferentially with ram 3 . Further travel downward by brake arms 27 is prevented by contact with base plate 21 . Spacer ring 7 transfers kinetic energy from the brake arms 27 and base plate 21 onto the main cylinder 5 or any associated support structure which may exist. Eyelets 11 and the structural strength of spacer ring 7 prevent brake system 1 from slipping and assure equal transfer of force directly downward, into existing main cylinder 5 or onto any associated cylinder support structures. Kinetic energies can be limited by limiting the down speed allowed before brake system 1 is actuated, thereby preventing damage to the brake system 1 , ram 3 or to the main cylinder 5 .
[0030] In the preferred embodiment, brake system 1 is actuated by loss of hydraulic pressure detected by direct feedback from the main cylinder 5 , by an electronic signal indicating loss of pressure in the cylinder 5 , by electronic signal from a down overspeed, or by an uncontrolled down motion detector.
[0031] Brake system 1 is actuated by downward motion of actuation rod 35 attached to the actuation assembly, generally identified by 33 . The top of the actuation rod 35 has a disc shaped metal wafer 37 that is received inside shaped hollows or routs 39 in the brake arms 27 . This assures registration between both brake arms.
[0032] Hydraulic actuation of brake arms 27 is accomplished by the hydraulic actuation assembly, generally referenced by the number 38 . The hydraulic actuation assembly 38 is located in and around feedback control cylinder 43 which is fixed between upper hydraulic cylinder bracket arm 46 and lower hydraulic cylinder bracket arm 48 of hydraulic cylinder bracket 55 , both bracket arms 46 , 48 being fixed to hydraulic cylinder bracket 55 . The hydraulic actuation assembly 38 comprises feedback cylinder 43 having portal 41 to receive the lower end 46 of actuation rod 35 , plunger 47 fixed to the lower end 46 of actuation rod 47 , and helical compression spring 45 which is engaged over and around the lower end 47 of actuation rod 35 , one end of compression spring 45 engaging the inside surface of the top of feedback cylinder 43 and the other end engaging plunger 47 .
[0033] Helical compression return spring 45 urges plunger 47 , and actuation rod 35 fixed thereto, downward. Under normal conditions, hydraulic pressure in feedback cylinder 43 , in fluid communication with main cylinder 5 , overcomes the compressed spring energy of return spring 45 , urging plunger 47 upward, which in turn urges control rod 35 upward, which then urges brake arms 27 into ready or standby position.
[0034] Loss of hydraulic pressure in the main cylinder 5 , is communicated to feedback cylinder 43 through hose 49 (FIGS. 1 and 2). Return spring 45 overcomes the reduced pressure in feedback cylinder 43 urging plunger 47 and attached actuation rod 35 downward pulling brake arms 27 into contact with ram 3 . Friction resulting from contact of accretable material 31 on the friction material mounting surface 28 of brake arms 27 urges brake arms 27 further downward into contact with ram 3 until brake arms 27 rest on horizontal base plate 21 . The accretable friction material 31 on brake arms 27 grips ram 3 with sufficient frictional force to stop the downward motion of ram 3 .
[0035] Electronic actuation of brake arms 27 is accomplished by the electronic control assembly generally referenced by the number 40 comprising control bracket 57 fixed to spacer ring 7 , upper solenoid bracket arm 61 , and lower solenoid bracket arm 63 , both being fixed to control bracket 57 . Electronic actuation assembly 40 further comprises, electronic activator rod 59 , and helical compression support spring 51 placed over and around electronic actuation control rod 59 , the upper end of support spring 51 engaging lower surface of hydraulic control assembly 38 , and the lower end of support spring 51 engaging the upper surface 51 of solenoid bracket 61 .
[0036] In the preferred embodiment, electronic activator rod 59 is fixed at its upper end, generally, to the hydraulic actuation assembly 38 , which is slidably engaged with slide bracket 44 , slide bracket 44 being fixed to control bracket 57 .
[0037] Solenoid helical compression support spring 51 , is selected to support the weight of brake arms 27 and hydraulic actuation assembly 38 . Tubular solenoid 65 is fixed between upper and lower solenoid bracket arms 61 and 63 . The lower end of electronic actuation rod 59 partially penetrates tubular solenoid 65 . The upper end of electronic actuation rod 59 is coupled to the underside of lower hydraulic cylinder bracket arm 48 of hydraulic cylinder bracket 55 . An electronic signal from a down overspeed detector or uncontrolled downward motion detector, not shown, causes an electric current in solenoid 65 generating a magnetic field of strength sufficient to urge electronic actuation rod 59 downward into tubular solenoid 65 , thereby pulling the entire hydraulic actuation assembly 38 , slidably engaged to slide bracket 44 , downward thereby actuating brake arms 31 .
[0038] In an alternate embodiment, not shown, the electrical actuation assembly 40 is the same as described above, except no hydraulic actuation assembly 38 is used. Instead, electronic actuation rod 59 is engaged directly with brake arms 27 . In this alternate embodiment, an electronic signal from a hydraulic pressure detector could also be used to actuate electronic actuation assembly 40 , in addition to a down overspeed or uncontrolled downward motion detector.
[0039] A variety of known down overspeed or uncontrolled downward motion detectors are available for use with this invention. For example, devices such as those disclosed in Coy, U.S. Pat. No. 4,638,888 which discloses an electronic system for detecting the hydraulic pressure in an elevator ram piston cylinder, and Ericson, U.S. Pat. No. 5,052,523 and Sobat, U.S. Pat. No. 3,942,607, which both disclose mechanical means for detecting the downward speed of an elevator. The specifications of these patents are hereby incorporated by reference in their entirety.
[0040] Given the generally small distance from the bottom of a standard hydraulic lift elevator to the top of the existing piston cylinder structure, a low profile device is desirable. The present device, in ready position is between four and five inches high. This is accomplished by keeping the fulcrum angle at 15 degrees as shown in the drawings, best seen in FIGS. 1 and 2. Therefore, it is easily mounted onto all existing elevator cylinders. Packing 16 is shown in FIG. 3 for illustrative purposes only, and varies from elevator to elevator depending on the manufacturer. The length of spacer ring 7 is dependent on the packing mechanism used by the various makes.
[0041] In general, the packing of all rams is located in the cylinder head at the top of the cylinder. The packing is the seal which retains the oil pressure and allows the smooth ram wall to slide relatively freely through it. Generally, there is some bypass of oil through this seal. When this bypassed oil is excessive it is customary to change the packing. As common as this procedure is, it is desirable to allow easy and open access to the cylinder head. As explained previously, the present invention utilizes a three point eyelet mounting. Any one of eyelets 11 can act as a pivot to rotate brake system 1 away from main cylinder 5 to allow access for servicing. By assuring enough range of motion by having a feedback hose 49 and electrical wiring of sufficient length, the device is easily rotated for access to packing 16 without the need to disconnect electrical wiring or hydraulic connections.
[0042] National, state and local codes provide regulations for periodic testing of safety devices, so it is desirable to retest without damaging either the ram or the brake. Prototype testing to date has shown less than twenty thousandths of an inch deformation of the annealed copper at the open edges of the annealed copper bar, where the brakes meet centrally when closed, and no permanent deformation elsewhere. Thus periodic testing is available, and the common practice of blocking the elevator to serve as a stable working platform is easily done by manually setting the brake.
[0043] The preferred embodiment described herein is illustrative only and although the examples given include many specificities, they are intended as illustrative of only one possible embodiment of the invention. Other embodiments and modifications will, no doubt, occur to those skilled in the art. Thus, the examples given should only be interpreted as illustrations of some of the preferred embodiments of the invention, and the full scope of the invention should be determined by the appended claims and their legal equivalents.
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An arrestor for any hydraulic ram or other cylinder but primarily for an emergency brake for lifting elevators. The present invention is a jack arrestor utilizing two lever acting brake arms lined with an accretable metal as the friction material. When actuated, the brake arms contact the ram circumferentially to slow and stop the falling ram. The lining material is machined inside the brake arms to a diameter slightly less than the diameter of the ram and when actuated, the accretable material on the brake arms contacts the ram with sufficient frictional force to stop the downward motion of the ram. The safety brake may be actuated by loss of hydraulic pressure, by an electronic signal from a hydraulic pressure detector, by down overspeed or by an uncontrolled down motion detector. In the case of the hydraulic pressure detector, reapplication of normal pressure in the hydraulic cylinder will automatically reset the brake.
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[0001] This application is a continuation of U.S. patent application Ser. No. 10/132,886, filed Apr. 24, 2002 entitled: METHOD FOR MULTI-TASKING MULTIPLE JAVA VIRTUAL MACHINES IN A SECURE ENVIRONMENT.
[0002] This application incorporates by reference U.S. patent application Ser. No. 09/841,753, filed Apr. 24, 2001 entitled: OPEN COMMUNICATION SYSTEM FOR REAL-TIME MULTIPROCESSOR APPLICATIONS and U.S. patent application Ser. No. 09/841,915, filed Apr. 24, 2001 entitled: METHOD AND APPARATUS FOR DYNAMIC CONFIGURATION OF MULTIPROCESSOR SYSTEM.
BACKGROUND OF THE INVENTION
[0003] Java is a robust, object-oriented programming language expressly designed for use in the distributed environment of the Internet. Java can be used to create complete applications that may run on a single computer or be distributed among servers and clients in a network. A source program in Java is compiled into byte code, which can be run anywhere in a network on a server or client that has a Java virtual machine (JVM).
[0004] A JVM describes software that is nothing more than an interface between the compiled byte code and the microprocessor or hardware platform that actually performs the program's instructions. Thus, the JVM makes it possible for Java application programs to be built that can run on any platform without having to be rewritten or recompiled by the programmer for each separate platform.
[0005] Jini is a distributed system based on the idea of federating groups of users and the resources required by those users. Resources can be implemented either as hardware devices, software programs, or a combination of the two. The Jini system extends the Java application environment from a single virtual machine to a network of machines. The Java application environment provides a good computing platform for distributed computing because both code and data can move from machine to machine. The Jini infrastructure provides mechanisms for devices, services, and users to join and detach from a network. Jini systems are more dynamic than is currently possible in networked groups where configuring a network is a centralized function done by hand.
[0006] However, the Java/Jini approach is not without its disadvantages. Both Java and Jini are free, open source applications. The Java application environment is not designed for controlling messaging between different machines. For example, the Java application is not concerned about the protocols between different hardware platforms. Jini has some built-in security that allows code to be downloaded and run from different machines in confidence. However, this limited security is insufficient for environments where it is necessary to further restrict code sharing or operation sharing among selected devices in a secure embedded system.
SUMMARY OF THE INVENTION
[0007] The present invention allows construction of a secure, real-time operating system from a portable language such as Java that appears to be a Java virtual machine from a top perspective but provides a secure operating system from a bottom perspective. This allows portable languages, such as Java, to be used for secure embedded multiprocessor environments.
[0008] The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a diagram showing a java stack with an additional Secure Real-time Executive (SRE) layer.
[0010] FIG. 2 is a diagram of a multiprocessor system that runs multiple Java Virtual Machines that each include a SRE.
[0011] FIG. 3 is a detailed diagram of the managers in the SRE.
[0012] FIG. 4 is a block diagram of how the SRE manages a multiprocessor system.
[0013] FIG. 5 is a bock diagram showing how a task manager in the SRE operates the multiprocessor system in a lock-step mode.
DETAILED DESCRIPTION
[0014] A java application stack includes a Java layer 5 for running any one of multiple different applications. In one example, the applications are related to different vehicle operations such as Infrared (IR) and radar sensor control and monitoring, vehicle brake control, vehicle audio and video control, environmental control, driver assistance control, etc. A Java Virtual Machine (JVM) layer 16 provides the hardware independent platform for running the Java applications 5 . A Jini layer 12 provides some limited security for the Java applications that run on different machines. However, the Jini layer 12 does not provide the necessary reconfiguration and security management necessary for a distributed real-time multiprocessor system.
[0015] A Secure Real-time Executive (SRE) 14 provides an extension to the JVM 16 and allows Java to run on different processors for real-time applications. The SRE 20 manages messaging, security, critical data, file I/O multiprocessor task control and watchdog tasks in the Java environment as described below. The JVM 16 , Jini 12 and SRE 14 can all be implemented in the same JVM 10 . However, for explanation purposes, the JVM 10 and the SRE 14 will be shown as separate elements.
[0016] FIG. 2 shows a system 15 that includes multiple processors 16 , 18 , 20 , 22 and 24 . Each processor includes one or more JVMs 10 that run different Java applications. For example, processor 16 includes one Java application 28 that controls a vehicle security system and another Java application 26 that controls the vehicles antilock brakes. A processor 18 includes a Java application 30 that controls audio sources in the vehicle. Other processors 20 and 22 may run different threads 32 A and 32 B for the same sensor fusion Java application 32 that monitors different IR sensors. Another thread 32 C on processor 24 monitors a radar sensor for the sensor fusion Java application 32 .
[0017] The SRE 14 runs below the JVMs 10 in each processor and control tasks, messaging, security, etc. For example, the Java application 26 controls vehicle braking according to the sensor data collected by the sensor fusion Java application 32 . The SRE 14 in one example prevents unauthorized data from being loaded into the processor 16 that runs brake control application 26 . The SRE 14 also prevents other Java applications that are allowed to be loaded into processor 16 from disrupting critical braking operations, or taking priority over the braking operations, performed by Java application 26 .
[0018] For example, the SRE 14 may prevent noncritical vehicle applications, such as audio control, from being loaded onto processor 16 . In another example, noncritical operations, such as security control application 28 , are allowed to be loaded onto processor 16 . However, the SRE 14 assigns the security messages low priority values that will only be processed when there are no braking tasks in application 26 that require processing by processor 16 .
[0019] The SRE 14 allows any variety of real-time, mission critical, nonreal-time and nonmission critical Java applications to be loaded onto the multiprocessor system 15 . The SRE 14 then automatically manages the different types of applications and messages to ensure that the critical vehicle applications are not corrupted and processed with the necessary priority. The SRE 14 is secure software that cannot be manipulated by other Java applications.
[0020] The SRE 14 provides priority preemption on a message scale across the entire system 15 and priority preemption on a task scale across the entire system 15 . So the SRE 14 controls how the JVMs 10 talk to each other and controls how the JVMs 10 are started or initiated to perform tasks. The SRE 14 allows programmers to write applications using Java in a safe and secure real time environment. Thus, viruses can be prevented by SRE 14 from infiltrating the system 15 .
[0021] While the explanation uses Java as one example of a programming environment where SRE 14 can be implemented, it should be understood that the SRE 14 can be integrated into any variety of different programming environments that may run in the same or different systems 15 . For example, SRE 14 can be integrated into an Application Programmers Interface (API) for use with any programming language such as C++.
[0022] FIG. 3 shows the different functions that are performed by the SRE 20 . Any combination of the functions described below can be provided in the SRE 20 . A message manager 50 controls the order messages are received and transmitted by the different Java applications. A security manager 52 controls what data and messages are allowed to be received or transmitted by different Java applications. A critical data manager 54 controls what data is archived by the different Java applications.
[0023] A data manager 56 controls what data is allowed to be transferred between different processors. A task manager 58 controls the order tasks are performed by the different JVMs. A reconfiguration manager 60 monitors the operation of the different processors in the system and reassigns or reconfigures Java applications and Java threads to different processors according to what processors have failed or what new processors and applications have been configured into system 15 .
[0024] The message manager 50 partially corresponds to the priority manager 44 shown in FIG. 2 of pending patent application Ser. No. 09/841,753, the critical data manager 52 partially corresponds with the logging manager 44 shown in FIG. 2 of the copending '753 patent application, and the security manger 54 a least partially corresponds with the security manager 40 shown in the '753 patent application. The data manager 56 at least partially corresponds with the data manager 42 shown in FIG. 2 of pending patent application Ser. No. 09/841,915, the task manager 58 partially corresponds to the device manger 46 shown in FIG. 2 of the '915 application, and the configuration manager 60 at least partially corresponds to the configuration manager 44 shown in FIG. 2 of the '915 patent application. The descriptions of how the different managers 50 - 60 operate similarly to the corresponding managers in the '753 and '915 patent applications are herein incorporated by reference and are therefore not described in further detail.
[0025] However, some specific tasks performed by the managers 50 - 60 are described below in further detail.
[0026] FIG. 4 shows in more detail how the SRE 14 operates. One of the operations performed by the task manager 58 is to control when different tasks are initiated on different processors. For example, a first Global Positioning System (GPS) thread 62 is running on a JVM in a processor 80 . Another sensor fusion thread 64 is running on a different processor 82 . Block 74 represents the Java Virtual Machine operating in each of processors 80 and 82 . A master JVM 74 may run on either processor 80 , processor 82 or on some other processor.
[0027] The task manager 58 sends an initiation command 66 to the GPS thread 62 to obtain location data. The task manager 58 then directs the obtained GPS data 68 through a link to the sensor fusion thread 64 for subsequent processing of GPS data 68 . The link may be any bus, such as a PCI bus, serial link such as a Universal Serial Bus, a wireless link such as blue tooth or IEEE 802.11, or a network link such as Ethernet, etc.
[0028] The configuration manager 60 acts as a watchdog to make sure that the GPS thread 62 and the sensor fusion thread 64 are each running correctly. In one example, separate configuration managers 60 in each processor 80 and 82 sends out periodic signals to the other configuration managers 60 in the other processors. Any one of the configuration managers 60 can detect a processor or application failure by not receiving the periodic “ok” signals from any one of the other processors for some period of time. If a failure is detected, then a particular master configuration manager 60 in one of the processors determines where the task in the failed processor is going to be reloaded. If the master configuration manager 60 dies, then some conventional priority scheme, such as round robin, is used to select another configuration master.
[0029] If a failure is detected, say in the processor 82 that is currently performing the sensor fusion thread 64 , a message is sent from the configuration manager 60 notifying the task manager 58 which processor is reassigned the sensor fusion thread. In this example, another sensor fusion thread 76 in processor 84 is configured by the configuration manager 60 .
[0030] The critical data manager 52 manages the retention of any critical data 72 that was previously generated by the sensor fusion thread 64 . For example, the critical data manager 54 automatically stores certain data and state information that was currently being used in the sensor fusion thread 64 . The critical data may include GPS readings for the last 10 minutes, sensor data obtained from sensors in other processors in the vehicle over the last 10 minutes. The critical data may also include any processed data generated by the sensor fusion thread 64 that identifies any critical vehicle conditions.
[0031] The critical data manager 52 also determines which data to archive generally for vehicle maintenance and accident reconstruction purposes.
[0032] The configuration manager 60 directs the critical data 72 to the new sensor fusion thread 76 . The task manager 74 then redirects any new GPS data obtained by the GPS thread 78 to the new sensor fusion thread 76 and controls sensor fusion tasks from application 76 . Thus, the configuration manager 60 and the task manager 58 dynamically control how different Java threads are initialized, distributed and activated on different processors.
[0033] The message manager 50 determines the priority of sent and received messages. If the data transmitted and received by the sensor fusion thread 76 is higher priority than other data transmitted and received on the processor 84 , then the sensor fusion data will be given priority over the other data. The task manager 58 controls the priority that the sensor fusion thread 76 is giving by processor 84 . If the sensor fusion thread 76 has higher priority than, for example, an audio application that is also being run by processor 84 , then the sensor fusion thread 76 will be performed before the audio application.
[0034] The SRE 14 can be implemented in any system that needs to be operated in a secure environment. For example, network servers or multiprocessors operating in a home environment. The multiprocessors in home appliances, such as washer and dryers, home computers, home security systems, home heating systems, can be networked together and operate Java applications. The SRE 14 prevents these multiple processors and the software that controls these processors from being corrupted by unauthorized software and also allows the applications on these different processors to operate as one integrated system.
[0035] The SRE 14 is a controlled trusted computing based that is not accessible by non-authorized application programmers and anyone in the general public. Therefore, the SRL 14 prevents hacking or unauthorized control and access to the processors in the vehicle.
Task Controlled Applications
[0036] Debugging is a problem with multiprocessor systems. The task manager 58 allows the Java applications to be run in a lock-step mode to more effectively identify problems in the multiprocessor system 15 .
[0037] FIG. 5 shows a path 90 taken by a vehicle 92 . In one application, the position of the vehicle 92 is sampled every second t 1 , t 2 , t 3 , t 4 , etc. The position of the vehicle 92 is sampled by a GPS receiver in vehicle 92 that reads a longitudinal and latitudinal position from a GPS satellite. The GPS receiver is controlled by the GPS thread 62 that receives the GPS data and then sends the GPS data to a sensor fusion thread 64 that may run on the same or a different processor in the vehicle 92 . The sensor fusion thread 64 can perform any one of many different tasks based on the GPS data. For example, the sensor fusion thread 64 may update a map that is currently being displayed to the driver of vehicle 92 or generate a warning signal to the vehicle driver.
[0038] For each sample period t N , the task manager 58 sends a request 94 to the GPS thread 62 to obtain GPS data. The task manager 58 uses a clock 96 as a reference for identifying each one second sample period. Each time a second passes according to clock 96 , the task manager 58 sends out the request 94 that wakes up the GPS thread 62 to go read the GPS data from the GPS satellite. Once the GPS data has been received, the GPS thread 62 passes the GPS data 96 to the sensor fusion thread 64 . The GPS thread 62 then goes back into an idle mode until it receives another activation command from the task manager 58 .
[0039] The task manager 58 can control when the GPS thread 62 is woken up. Instead of the GPS thread 62 being free running, the GPS thread 62 is operating according to a perceived time controlled by the task manager 58 . The task manager 58 may send the activation request 94 to the GPS thread 62 once every second during normal sensor fusion operation. When the system is in a debug mode, however, the task manager 58 may only send one activation command 94 . This allows the other operations performed by the system 89 to be monitored and determine how the single sampling of GPS data 96 propagates through system 89 . The task manager 58 may also delay or disable task initiation to other threads, so that the processing of the GPS data 96 can be isolated.
[0040] The task manager 58 can isolate any state in the overall system 89 , such as the state of system 89 after a first GPS reading by GPS thread 62 or the state of system 89 after the thirty second GPS reading by GPS thread 62 by controlling when and how often activation commands 94 are sent to GPS thread 62 . In a similar manner, the task manager 58 can control when other tasks are performed by the system 89 , such as when the sensor fusion thread 64 is activated.
[0041] Thus, the task manager 58 controls when Java applications are activated effectively running the overall system 89 in a lock-step mode. The task manager 58 can control the initiation of multiple tasks at the same time. This allows the task manager to control what parameters and operations are performed and used by the different Java threads so that different states in the multiprocessor system 89 can be detected and monitored more effectively.
[0042] One application for the task controlled applications is for accident reconstruction. The critical data manager 52 ( FIG. 3 ) may save different vehicle parameters from a vehicle that has been in an accident. For example, sensor data, brake data, speed data, etc. The task manager 58 can feed the saved data into the different Java applications in a lock-step mode to determine how each Java thread processes the saved data. This can then be used to identify any failures that may have occurred in the system 89 .
[0043] The system described above can use dedicated processor systems, micro controllers, programmable logic devices, or microprocessors that perform some or all of the communication operations. Some of the operations described above may be implemented in software and other operations may be implemented in hardware.
[0044] For the sake of convenience, the operations are described as various interconnected functional blocks or distinct software modules. This is not necessary, however, and there may be cases where these functional blocks or modules are equivalently aggregated into a single logic device, program or operation with unclear boundaries. In any event, the functional blocks and software modules or described features can be implemented by themselves, or in combination with other operations in either hardware or software.
[0045] Having described and illustrated the principles of the invention in a preferred embodiment thereof, it should be apparent that the invention may be modified in arrangement and detail without departing from such principles. Claim is made to all modifications and variation coming within the spirit and scope of the following claims.
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The present invention allows construction of a secure, real-time operating system from a portable language such as Java that appears to be a Java virtual machine from a top perspective but provides a secure operating system from a bottom perspective. This allows portable languages, such as Java, to be used for secure embedded multiprocessor environments.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage application of International Application No. PCT/JP2013/007069 entitled “Cooling System for Electronic Device Storing Apparatus and Cooling System for Electronic Device Storing Building,” filed on Dec. 3, 2013, which claims the benefit of the priority of Japanese Patent Application No. 2012-264430, filed on Dec. 3, 2012, the disclosures of each of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
The present invention relates to a cooling system for an electronic device storing apparatus and the like, and, more particularly, to a cooling system for such as an electronic device storing apparatus which cools heat from a plurality of heating sources such as servers.
BACKGROUND ART
In recent years, an amount of information processing that is needed is increasing along with the improvement of information processing technologies and the development of internet environments. Associated with such tendency, data center business which installs and operates equipment such as servers, communication devices, fixed-line phones and IP (Internet Protocol) telephones that are used for the internet is being paid attention.
A lot of electronic devices such as a computer are installed in a server room of such a data center. As a method to install electronic devices in a server room, using a rack-mounting system is the mainstream. A rack-mounting system is a method standardized by JIS (Japanese Industrial Standards) and EIA (Electronic Industries Alliance), in which flat type electronic devices are installed in a rack in a stacked manner.
In order to reserve a space in a server room sufficiently, it is desired to mount electronic devices into a rack as much as possible. Therefore, it is needed for electronic devices that the heights of them are made to be short respectively. Meanwhile, the height of an electronic device such as a 1 U (Unit) server and a blade server which are generally called a rack-mount type server is about 40 millimeters. In order to cool heat exhausted by such rack-mount type servers, it is necessary to simultaneously cool a plurality of stacked heat sources having different heights.
An underfloor air-conditioning system is a general cooling system for a data center. To cool servers in a data center efficiently, in an underfloor air-conditioning system, a building in which servers are laid is made to have double floors, and cool wind from air-conditioning equipment is supplied to server racks from an under floor through a floor grill, which is provided on a floor surface and is made of a metal plate having a plurality of opened holes. This underfloor air-conditioning system can supply a cool wind to a server rack efficiently because a warm air of a server and a cool wind from air-conditioning equipment can be separated through double floors.
A cooling air volume required for a server rack varies greatly by a load of a server. Therefore, there is disclosed in patent document 1 a structure in which a supplied amount of a cold air that is blown out to the front of a rack is controlled according to a heat generation amount of the rack to reduce motive power for cold air supply and to prevent occurrence of a hot spot.
That is, an average operating rate for each rack is obtained from an operating rate of each server taken in from a control server, the maximum air volume of a rack is multiplied by the average heat generation amount of the rack obtained from that value, and, by that, a signal of a required air volume is generated. Based on this required air volume signal, the number of rotations of a floor fan of each rack is being controlled.
Furthermore, there is provided a temperature correction arithmetic processing part to correct a required air volume signal when an inlet detection temperature of an upper part thermometer provided in a position corresponding to the inlet of a server exceeds an inlet temperature that has been set.
Thus, by obtaining an air volume required for a server from an average operating rate of a server rack and a server inlet air temperature of the uppermost stage of the server rack, a required air volume and a cool wind temperature of air-conditioning equipment are adjusted according to a server operating rate which changes every moment and a cool wind having the most suitable temperature and an air volume is supplied to each server.
CITIZENS LIST
Patent Literature
[PTL 1] Japanese Patent Application Laid-Open No. 2011-226737
SUMMARY OF INVENTION
Technical Problem
However, a cooling system in patent document 1 described above has a problem. That is, this system just supplies an air volume required for servers as a whole by obtaining an average operating rate for each rack from operating rates of servers. Accordingly, heat control of an individual server cannot be made even though a generated heat amount is different depending on each server.
The present invention has been made in consideration of settling these problems, and its object is to provide a cooling system which can control the performance of a heat exchanger in more detail.
Solution to Problem
A cooling system for an electronic device storing apparatus, comprising: a rack including an electronic device and a plurality of placement shelves to place said electronic device; in said rack, a vaporizer having a refrigerant internally being mounted; outside said rack, a condensing part connected with said vaporizer by a laying pipe being installed; and a refrigerant adjustment means for adjusting a height of a refrigerant surface in said vaporizer.
Advantageous Effects of Invention
By a cooling system according to the present invention, a heat exchanger performance can be controlled in more detail.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a sectional view showing a data center.
FIG. 2 is an upper part sectional view showing a data center.
FIG. 3 is a front view of a cooling system.
FIG. 4 is a diagram showing a structure of a mobile tank.
FIG. 5 is a diagram showing a cooling system of a second exemplary embodiment.
FIG. 6 is a detail view of a tank fixing plate.
FIG. 7 is a diagram showing a cooling system of a third exemplary embodiment.
DESCRIPTION OF EMBODIMENTS
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to a drawing. However, although limitation that is technically desirable to implement the present invention is made to the exemplary embodiments described below, the scope of the invention is not limited to the followings.
FIG. 1 is a sectional view showing a data center. In order to cool servers in a data center 1 , a rotary wing of a circulation FAN 10 rotates, and an outside air is taken in from an air intake opening 2 of the data center 1 . This outside air that has been taken in is absorbed into a server by a FAN inside the server operating. The air absorbed into the server becomes a warm air by being heated by inner heating elements, and then exhausted from an air exhaust opening of the server.
The warm air conducts heat to a refrigerant 16 in a plurality of heat receiving parts installed in a server rack rear surface, and part of the heat which the warm air has had is absorbed by the refrigerant 16 as a latent heat when the refrigerant 16 performs a phase change to vapor from liquid. Then, the temperature of the warm air declines as a result of losing heat. This warm air is discharged to outside the data center 1 through the circulation FAN 10 .
Because a partition or the like does not exist around a server rack, there occurs a so-called short return phenomenon in which part of a warm air which has not been discharged turns around the server rack 6 and is supplied to the air intake part of the server rack 6 again.
By vapor passing through inside a steam pipe 8 , the heat from the warm air transferred to the refrigerant in a vaporizer 4 is carried to a condenser 5 in a condensing chamber 11 of the data center 1 by buoyancy. In the condenser 5 , the heat of the steam of the refrigerant 16 is carried to outside air by performing heat exchange with the outside air circulated by a condensation FAN 12 of the condensing chamber 11 . On this occasion, the vapor is condensed into liquid.
The condensed refrigerant is carried to a tank 13 in the uppermost part shown in FIG. 3 through a condenser pipe 9 . The condensed refrigerant liquid carried to the tank 13 is supplied to the vaporizer of the uppermost stage part through a heat exchanger connecting pipe 14 . A tank liquid level rises as a condensed refrigerant liquid goes on being supplied. However, when the tank liquid level rises to the same height as the connecting port of a tank connecting pipe 15 connected to the tank 13 , a solvent liquid is connected, not to the heat receiver of the uppermost stage part, but to the tank 13 in a lower stage through the tank connecting pipe 15 . A condensed solvent liquid is supplied into all of a plurality of pieces of vaporizer 4 by repeating such operations. Exhaust heat of an electronic device is discharged to outside the data center 1 by the above cycle.
Next, action and effect in this exemplary embodiment will be described with reference to a drawing.
First, explanation about how exhaust heat from an electronic device is discharged to outside the data center 1 will be made. In FIG. 1 , there is shown a sectional view of a server rack 6 which stores a plurality of electronic devices and a data center 1 equipped with a plurality of server racks. FIG. 2 indicates a top view of the data center 1 .
As shown in FIG. 1 , the air intake opening 2 which takes in an outside air, the air exhaust opening 3 which discharges the outside air and the circulation FAN 10 are being installed in the data center 1 . A plurality of pieces of vaporizer 4 having the refrigerant 16 filled inside them are installed in the rear face of the server rack 6 arranged in the center part of the data center 1 , from the upper part to the lower part of the server rack 6 . It is desirable to provide the vaporizer 4 in a manner corresponding to each server rack. As shown in FIG. 2 , a plurality of server racks which are constituted by a plurality of servers stacked vertically are being arranged laterally. A cooling system shown in FIG. 3 is provided for each server rack respectively.
Pieces of temperature sensor 7 for measuring an exhaust temperature from servers are installed in the server side portions of these plurality of vaporizers, and pieces of temperature sensor 7 for measuring an air temperature after heat exchange are installed in portions of the vaporizers in the room interior side of the data center 1 .
A low-boiling-point refrigerant 16 such as hydrofluorocarbon and hydro-fluoro ether is used as the refrigerant 16 used in the vaporizer 4 . The vaporizer 4 is connected to the condenser 5 in the condensing chamber 11 via the steam pipe 8 through which mainly vapor passes to the condensing chamber 11 provided inside the data center 1 . From the condenser 5 , the condenser pipe 9 through which a condensate liquid having phase-changed to liquid from vapor in the condenser 5 passes communicates with the vaporizer 4 , and thus the vaporizer 4 and the condenser 5 are connected through the steam pipe 8 and the condenser pipe 9 .
Both of the vaporizer 4 and the condenser 5 are heat exchangers to perform heat exchange between air and the refrigerant 16 , and, for example, a heat exchanger of a fin and tube type is used. Although not illustrated in FIG. 1 , the condensing chamber 11 is provided with an air intake opening and an air exhaust opening, and a condensation FAN which promotes heat exchange between air and the refrigerant 16 is installed in the condenser 5 .
A plurality of pieces of vaporizer 4 are arranged vertically as described above, and the tank 13 that stores the refrigerant 16 is installed in each vaporizer as shown in FIG. 3 . The tank 13 of the vaporizer 4 of the uppermost stage part is connected to the condenser 5 shown in FIG. 1 and FIG. 3 through the condenser pipe 9 . The tank 13 are connected with the vaporizer 4 through the heat exchanger connecting pipe 14 , and the pieces of tank 13 are connected with each other through the tank connecting pipe 15 . Meanwhile, a desirable structure is that the heat exchanger connecting pipe 14 is movable or elastic corresponding to an up-and-down movement of a tank mentioned later. Pieces of steam pipe 8 of respective pieces of vaporizer 4 are brought together to one piece, and then connected to the condenser 5 as shown in FIG. 3 .
Each piece of tank 13 is installed on and fixed to a mobile plate 17 which can change its height in the vertical direction of the tank 13 as shown in FIG. 4 . This mobile plate 17 moves up and down by converting motive power of a driving machine such as a motor into a force in the vertical direction. Operations of this driving machine are controlled by a control unit which is not illustrated. Based on temperature information obtained from the temperature sensor 7 , the control unit performs a tank up-and-down movement mentioned later and power control of a circulation fan 10 . By the tank 13 operating up and down, a height of the refrigerant 16 in the vaporizer 4 connected to the tank changes.
Next, control of a circulation fan using the temperature sensor 7 and control of the cooling performance of a heat receiving part will be described. An exhaust air temperature of a server rises by increase of a load of the server in time series. When the exhaust temperature of a server is 40 degree C. or more, for example, an intake air of a server will absorb an exhaust air directly due to a short return phenomenon mentioned above in which an exhaust air of a server turns around the server rack 6 .
Many electronics manufacturers standardize to set the entrance air temperature of a server to 40 degree C. or less, and thus the operational reliability of a server is damaged if nothing is done. Accordingly, when the temperature sensor 7 of a heat receiving part in the side of the data center 1 becomes 40 degree C. or more, a control unit performs an operation which makes a driving machine raise a refrigerant height inside the heat receiving part by making the mobile plate of the tank 13 rise in order to make cooling performance of the heat receiving part be improved.
When a refrigerant height is made to rise, heat exchange becomes easy as a result of using a whole heat receiving part, and the exhaust temperature that has become 40 degree C. or more becomes 40 degree C. or less by enhanced heat exchange. At the same time, the control unit reduces motive power of the circulation FAN 10 to make a short return mentioned above be easy to occur. Although the entrance air temperature of a server goes on rising when a short return is caused, a rise of the entrance air temperature of the server is suppressed because heat exchange has become easy to be performed at the same time.
However, cooling performance of a heat exchanger has its own limitation. Such cooling performance can be expressed in a temperature difference (ΔT) between the temperature sensor 7 in the server side and the temperature sensor 7 in the data center 1 side. When a temperature rise inside a server is 10 and ΔT mentioned above is 5 degree C., for example, cooling performance is said that 50% of heat is being absorbed. The maximum value of this ΔT is decided by the area and the thickness of a heat exchanger. Accordingly, decline of motive power of the circulation FAN 10 mentioned above is controlled by a control unit such that it is conducted until the performance of the heat exchanger reaches the maximum value of ΔT.
Many servers have a standard value of 15 degree C. for an intake air temperature of a server also in the low temperature side. In the case of midwinter, an outside temperature of the data center 1 becomes 15 degree C. or less, and thus it is necessity to heat air in order to make the intake air temperature of a server be no smaller than 15 degree C. In this case, heat generation of a server itself is used. When the temperature of the temperature sensor 7 in the data center 1 side is no more than 15 degree C., the control unit makes the mobile plate of the tank 13 descend.
By this movement, a liquid level inside the heat receiving part is declining. When a liquid level declines, heat exchange is suppressed because an area where a heat receiving part is filled with the refrigerant 16 goes on becoming smaller. The descent of this liquid level is made until the refrigerant 16 inside the heat receiving part disappears. Around the same time with this movement of the mobile plate, the control unit makes the motive power of the circulation FAN 10 goes on being lowered. When the motive power of the circulation FAN 10 is declining, an intake air temperature of the server is rising because an amount of an exhaust air of the server that is supplied to an intake air of the server directly goes on increasing by a short return mentioned above. At the time point when an intake air temperature of the server becomes 15 degree C., decline of the motive power of the circulation FAN 10 is stopped and it is operated at the motive power at that time.
An effect by the above-mentioned action exists in a point that temperature control can be performed for each server to which a vaporizer is provided because the performance of an individual evaporator can be controlled. In addition, temperature control is made by controlling a movement which is an up-and-down movement of a tank that is easy to be controlled, and thus the system is not complicated.
Next, the second exemplary embodiment will be described using a drawing. Structures overlapping with the first exemplary embodiment are omitted. A difference from the first exemplary embodiment in the second exemplary embodiment is a point that a mechanism to adjust a liquid level of the tank 13 is carried out by a tank fixing plate 18 , not by the mobile plate 17 , as shown in FIG. 5 . A plurality of pieces of tank fixing plate 18 are connected to a side face of a vaporizer. As shown in FIG. 6 , the tank fixing plate 18 has a hollow cutout enabling to fix the tank 13 . As shown in FIG. 5 , adjustment of a liquid level of a heat receiving part is performed by varying a position to mount the tank 13 in the vertical direction among a plurality of pieces of tank fixing plate 18 .
In the case of the second exemplary embodiment, it is necessary to move the tank 13 optionally by a human hand, and, thus, detailed control of a liquid level and the circulation FAN 10 corresponding to a load of a server as is the case with the first exemplary embodiment cannot be realized. Therefore, it is necessary to decide positions of the tank 13 in a high temperature period in summer and a low temperature period in winter, for example, in advance, and move the tank 13 beforehand. Effects are similar to those of the first exemplary embodiment.
Next, the third exemplary embodiment will be described using a drawing. Structures overlapping with the first exemplary embodiment are omitted similarly. A difference from the first exemplary embodiment in the third exemplary embodiment is a point that a mechanism to adjust a liquid level of the tank 13 is realized by a fluid control valve 19 as shown in FIG. 7 . In the tank 13 , there are provided a plurality of pieces of fluid control fluid control valve 19 in the vertical direction of the tank 13 . When it is desired to make a liquid level of a heat receiving part rise, by opening the fluid control valve 19 of the uppermost part shown in FIG. 7 and by closing the remaining two pieces of fluid control valve 19 , for example, a condensate liquid reaches the tank 13 in a lower stage when the liquid level reaches the fluid control valve 19 of the uppermost part.
In this exemplary embodiment, control of a liquid level of a heat receiving part is performed by control of the fluid control valve 19 , not by a form according to an up-and-down movement of the mobile plate 17 . Regarding control of a valve, a control unit can carry out control of a valve automatically according to temperature information from a temperature sensor just like the first exemplary embodiment. Alternatively, a valve may be adjusted by human hands as is the case with the second exemplary embodiment.
This application claims priority based on Japanese application Japanese Patent Application No. 2012-264430, filed on Dec. 3, 2012, the disclosure of which is incorporated herein in its entirety.
INDUSTRIAL APPLICABILITY
The present invention relates to a cooling system for such as an electronic device storing apparatus, and, more particularly, to a cooling system for such as an electronic device storing apparatus which cools heat from a plurality of heating sources such as a server.
REFERENCE SIGNS LIST
1 Data center
2 Air intake opening
3 Air exhaust opening
4 Vaporizer
5 Condenser
6 Server rack
7 Temperature sensor
8 Steam pipe
9 Condenser pipe
10 Circulation FAN
11 Condensing chamber
12 Condensation FAN
13 Tank
14 Heat exchanger connecting pipe
15 Tank connecting pipe
16 Refrigerant
17 Mobile plate
18 Tank fixing plate
19 Fluid control valve
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A cooling system of an electronic device storing apparatus of the present invention comprises: a rack including an electronic device and a plurality of placement shelves to place the electronic device; in the rack, a vaporizer having a refrigerant internally being mounted; outside the rack, a condensing part connected with the vaporizer by a laying pipe being installed; and a refrigerant adjustment means for adjusting a height of a refrigerant surface in the vaporizer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a 35 USC application of PCT/DE 00/03597 filed on Oct. 12, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is based on an injector for a fuel injection system for internal combustion engines, having a nozzle needle protruding into the valve control chamber.
2. Description of the Art
Injectors that are controlled by a magnet valve or a piezoelectric actuator are known. Regardless of the type of control, improvements in emissions and fuel consumption as well as noise produced by the internal combustion engine can be attained, among other provisions, by shortening the control times of the injectors. Shortened control times mean that the metering of the injection quantities is done more precisely, and that the course of injection can be designed with greater freedom. Finally, in modern internal combustion engines in motor vehicles, the available space is increasingly tight, which demands injectors of compact structure.
OBJECTS AND SUMMARY OF THE INVENTION
It is the primary object of the invention to furnish an injector for a fuel injection system for internal combustion engines whose control times are shortened and whose external dimensions are especially compact.
This object is attained according to the invention by an injector for a fuel injection system for internal combustion engines, having a valve control chamber controlling a nozzle needle, in which the valve control chamber is defined by an end face of the nozzle needle.
This injector has the advantage that by the omission of a long thrust rod and a valve piston, the number of components and the mass inertia of the moving parts of the injector are reduced. This makes short control times possible. In addition, the valve control chamber can be brought closer to the injection nozzle, making thinner nozzle needles possible as well. This effect contributes to a further reduction in the moving masses inside the injector.
With the omission of multiple components and the possible reduction in size of the components that remain, a marked reduction in the structural size of the injector is attained. The diameter ratios of the injector of the injection are approximately equivalent to those of an injection nozzle of the prior art.
Furthermore, in the version of the injector according to the invention, no leakage can occur in the closed state, so that there is also no need to provide a leaking oil outlet.
In a variant of the invention, it is provided that the valve control chamber is disposed in a valve body, so that the injector can be produced simply and economically.
In another version of the invention, the valve body protrudes into a pressure chamber, so that a compact design of the injector is attained and the number of sealing points remains low.
The invention furthermore provides that the pressure chamber communicates with a high-pressure fuel reservoir via an inlet conduit; that the valve control chamber communicates at least indirectly with a high-pressure fuel reservoir via an inlet throttle; and that the valve control chamber communicates with the pressure chamber via an inlet throttle, so that the requisite hydraulic connections between the valve control chamber, pressure chamber and high-pressure fuel reservoir can be achieved in a simple way.
The invention also provides that the valve control chamber can be made to communicate with a fuel return, via an outlet conduit, an outlet throttle, and a control valve, in particular a 2/2-way control valve or 2/3-way control valve, so that the pressure in the valve control chamber can be reduced by opening the control valve. As a consequence, the nozzle needle uncovers the sealing seat, and the injection begins.
A variant of the invention provides that the outlet conduit and an outlet throttle are disposed in the valve body, so that a further reduction in the requisite installation space is attained.
Further features of the invention provide that a closing spring braced against the valve body and at least indirectly against the nozzle needle is present in the pressure chamber; the closing spring is braced against a shoulder of the nozzle needle; or that a closing spring braced against the injector and against the nozzle needle is present in the valve control chamber, so that in the absence of fuel pressure the injector is always closed, and thus the uncontrolled outflow of fuel into the combustion chamber is prevented.
In one embodiment of the invention, it is provided that the diameter of the end face of the nozzle needle is greater than the diameter of the sealing line between the nozzle needle and a nozzle needle seat, so that for the same pressure in the valve control chamber and pressure chamber, the resultant hydraulic force always brings about a closure of the injector.
Further in the invention, it is provided that the control valve is actuated by a piezoelectric actuator, so that the control times of the injector of the invention are shortened further.
The object stated above is also attained by a fuel injection system for internal combustion engines, having a high-pressure fuel pump and having at least one injector having a valve control chamber controlling a nozzle needle, characterized in that the valve control chamber is defined by an end face of the nozzle needle, so that the fuel injection system of the invention can be used in internal combustion engines in which both a compact design and very short control times are required.
In a variant of the invention, the fuel injection system has a high-pressure fuel reservoir, so that the advantages of the injector according to the invention also benefit common rail fuel injection systems.
BRIEF DESCRIPTION OF THE DRAWING
Further features and advantages of the invention can be learned from the ensuing description, taken with the single FIGURE of the drawing which is a fragmentary cross section through an 309 injection of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing in detail, in an injector of the invention. Via a high-pressure connection 1 , the fuel, not shown, is carried through an inlet conduit 3 into a pressure chamber 5 of an injection nozzle 7 . The fuel originates in and has the presure of the high-pressure fuel reservoir (common rail), not shown. Via an inlet throttle 8 , a valve control chamber 9 communicates with the pressure chamber 5 . Via a control valve 11 , shown in only fragmentary fashion, the valve control chamber 9 can be made to communicate with a pressureless fuel return, not shown. Between the valve control chamber 9 and the control valve 11 , there are an outlet conduit 13 and an outlet throttle 14 .
The housing 15 of the injector is connected by a union nut 16 to a cap 17 . The cap 17 furthermore fixes a valve body 19 that protrudes into the pressure chamber 5 . In the valve body 19 , there is a guide bore 20 , having the diameter d 2 , for a nozzle needle 21 . The valve control chamber 9 disposed in the valve body 19 is defined by an end face 23 of the nozzle needle.
Between the valve body 19 and the housing 15 , there is a conical sealing seat 25 , which seals off the pressure chamber 5 from its surroundings. A cup spring 26 fastened between the cap 17 and the valve body 19 presses the valve body 19 permanently and with constant force against the sealing seat 25 .
The nozzle needle 21 prevents the fuel, which is under pressure, from flowing between injections out of the injection nozzle 7 through an injection port 27 into the combustion chamber, not shown. This is accomplished in that the nozzle needle 21 is pressed into a nozzle needle seat 29 and thus seals off the inlet conduit 3 from the combustion chamber, not shown. A circular sealing line forms between the nozzle needle 21 and the nozzle needle seat 29 . The diameter of the sealing line is designated as d 1 .
A closing spring 33 is present between a shoulder 31 of the nozzle needle 21 and the valve body 19 . The spring assures that the nozzle needle 21 is always closed when the fuel lacks any overpressure.
When the control valve 11 is closed, the same pressure prevails in both the valve control chamber 9 and the pressure chamber 5 . Via the end face 23 , this pressure exerts a hydraulic force acting on the nozzle needle 21 in the direction of the nozzle needle seat 29 . The same pressure exerts a hydraulic force, acting in the opposite direction, on the annular face defined by the diameters d 1 and of nozzle needle 21 . The resultant hydraulic force acts on the nozzle needle 21 in the direction of the nozzle needle seat 29 , because the end face 23 is larger than the annular face defined by the diameters d 1 and d 2 .
The injection nozzle 7 opens when the control valve 11 is opened and as a consequence the pressure in the valve control chamber 9 collapses. In that case, the resultant hydraulic force acts in the direction of the control valve 11 and lifts the nozzle needle 21 from the nozzle needle seat 29 . The fuel can thus flow out of the pressure chamber 5 into the combustion chamber via the injection port 27 , and the injection begins.
When the control valve 11 , which can be embodied as a 2/2-way control valve or a 2/3-way control valve, closes again, a high pressure builds up again in the valve control chamber 9 , and this high pressure is equal to the pressure in the pressure chamber 5 , so that the resultant hydraulic force presses the nozzle needle 21 back into the nozzle needle seat 29 , and the injection ends.
An especially advantageous feature of the injector of the invention is that it is very compact in structure. The diameter of an injector of the invention is equivalent to that of an injection nozzle of the prior art. Furthermore, the masses of the moving parts are very low, since a valve piston and a thrust rod can be omitted and the nozzle needle has very small dimensions. This leads to very short control times of the injector, which can be fully utilized particularly conjunction with a piezoelectric actuator-actuated control valve 11 . The tiniest possible preinjection quantities can for instance be realized. The low number of components also has cost advantages for production. Finally, no leakage losses occur, either.
The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.
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An injector for a fuel injection system is proposed, having an at least partial compensation for the hydraulic forces acting on the nozzle needle. In addition, the fuel volume to be controlled is reduced, so that short control times are possible.
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TECHNICAL FIELD OF THE INVENTION
[0001] The invention relates generally to hand held ink stampers, and more particularly to a single ink stamper that provides multiple stamp designs.
BACKGROUND OF THE INVENTION
[0002] Conventional hand-held, pre-inking ink stampers, like that disclosed by U.S. Pat. No. 6,499,398 issued to MacNeil, have a handle fixed to a platen holding an ink stamp die on the bottom of the platen. The platen is mounted within a frame or cover with an open bottom. The handle is positioned above the frame so that pushing the handle downward pushes the platen and stamp die downward and toward the open bottom of the frame in position to stamp whatever surface the frame bottom is abutting.
[0003] The pre-inking stampers, however, are limited because they can only provide a single stamping surface at one end of the stamper. A stamp die providing a different design or color needs to be provided by a separate stamper or the present stamper must be disassembled and reassembled with the new desired stamp die.
[0004] Thus, it is an object of the present invention to provide a hand-held ink stamper that provides more than one stamp die in order to provide alternative stamp designs or colors on a single ink stamper without the need for disassembly of the ink stamper.
[0005] These and other objects and advantages will be apparent from the following specification.
SUMMARY OF THE INVENTION
[0006] The problems mentioned above are solved by the present invention in which a two ended ink stamper has at least one handle with at least two ends. A first frame and a second frame are provided, and each frame is disposed adjacent to a different one of the ends of the handle. Each frame extends in a different direction from the handle. At least two platens are respectively operatively attached to, and disposed within, one of the frames for selective movement within the frame between a non-marking position and a marking position. Each platen is secured to the handle and extends outward from a different end of the handle. Thus, moving the handle moves the platens relative to the frames and between non-marking and marking positions.
[0007] In another aspect of the invention, each platen is attached to one of the frames with a resilient member biasing each frame away from the handle so that the platen is biased to the non-marking position.
[0008] In yet another aspect of the invention, the handle has interior walls generally shaped in the outline of a “+” to provide support for portions of the platens being inserted into the handle. The interior walls also provide locking grooves for receiving locking ribs on the platens in order to secure the platens to the handle. Finally, the interior walls also have stabilizing fins that abut, and are positioned between, the platens within the handle.
[0009] The following detailed description of embodiments of the invention, taken in conjunction with the appended claims and accompanying drawings, provide a more complete understanding of the nature and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a front and right side perspective view of an ink stamper in accordance with the present invention;
[0011] FIG. 2 is an exploded, top and back perspective view of the ink stamper in accordance with the present invention;
[0012] FIG. 3 is a plan view of a handle of the ink stamper in accordance with the present invention;
[0013] FIG. 4 is a cross sectional view of the handle taken along line IV-IV on FIG. 3 in accordance with the present invention;
[0014] FIG. 5 is a cross sectional view of the handle taken along line V-V on FIG. 3 in accordance with the present invention;
[0015] FIG. 6 is an elevational back view of a frame of the ink stamper shown partially in cross section in accordance with the present invention;
[0016] FIG. 7 is a top plan view of the frame of the ink stamper in accordance with the present invention;
[0017] FIG. 8 is a top and side perspective view of a platen for the ink stamper in accordance with the present invention;
[0018] FIG. 8A is cross sectional view of a portion of the ink stamper taken along the line 8 A- 8 A on FIG. 8 .
[0019] FIG. 9 is a bottom and side perspective view of a platen for the ink stamper in accordance with the present invention;
[0020] FIG. 10 is a front view of the ink stamper shown partially in cross section in accordance with the present invention; and
[0021] FIG. 11 is a right side view of the ink stamper shown partially in cross section in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Referring to FIGS. 1 and 2 , a hand-held, pre-inking stamper 10 has two cases or frames 12 , 14 on opposite ends of an actuator or handle 16 . Platens 18 and 20 are respectively disposed within a corresponding one of the frames 12 or 14 , and each of the platens is fixed to the handle 16 . Each platen 18 , 20 has a stamp die 22 or 24 and a retaining clip 26 or 28 that clips onto the platen and retains the stamp die on the platen. The stamp dies 22 , 24 are any known die, including those made of gels or ink refillable porous materials, and is not limited to any shape as long as it positions a stamp with a marking design at the face of retainers 26 , 28 . A hinged lid 30 , 32 is connected to the frame 12 or 14 to selectively cover the stamp dies.
[0023] Referring to FIGS. 2 and 3 , the handle 16 has a generally tubular body 34 with four exterior walls 36 a - d generally forming a rectangle, an open top end 37 and an open lower end 39 . Each exterior wall 36 a - d has vertically extending ribs 38 on an interior surface 40 of the exterior walls for guiding the handle as it slides on the frames 12 and 14 . As shown in FIGS. 3 and 5 , four of the ribs 38 have lateral protrusions 42 a - d which cooperatively act as a stopper against the frames 12 or 14 moving into the handle.
[0024] Handle 16 also has bending interior walls 44 , 46 that, cooperatively with front and back walls 36 a , 36 c , form the outline of a “+” shape as shown in FIG. 3 . The interior walls are shaped this way in order to provide support for portions of the platens 12 , 14 inserted into, and connecting to, the handle. The interior walls 44 , 46 extend from front and back exterior walls 36 a and 36 c of the handle, and each has a main brace 48 a , 48 b extending respectively from exterior sidewalls 36 b and 36 d to interior sidewalls 44 a , 46 a.
[0025] As illustrated in FIGS. 3-5 , the interior walls 44 , 46 have a plurality of stabilizer fins 50 extending inwardly and laterally from an interior surface 52 . The stabilizer fins 50 sit vertically between, and abut, the two platens 18 and 20 when the platens are fixed to the handle (see FIG. 10 ).
[0026] As shown in FIGS. 4 and 5 , handle 16 also provides horizontally extending locking grooves 54 , 56 respectively near the upper and lower ends of both interior sidewall 44 and 46 (interior sidewall 44 a is shown and sidewall 46 a has the same grooves). The grooves 54 , 56 receive locking ribs 106 or 108 extending from the platens 18 , 20 as explained below with regard to FIGS. 8 and 9 .
[0027] Referring to FIGS. 6 and 7 , frame 12 shown (frame 14 is the same) has a generally rectangular body 58 with an open bottom end 60 formed by four walls 62 a - d . Each wall 62 a - d has an upper portion 64 a - d pushed back from an outer periphery 66 and dimensioned to slide within handle 16 from the handle's upper and lower open ends 37 , 39 (see FIGS. 2 and 4 ). The upper portions 64 a - d are shaped to avoid the interior walls 44 , 46 of the handle 16 . A shoulder 68 connects the outer periphery 66 to the upper wall portions 64 a - d . Two of the upper portion sidewalls 64 b , 64 d has a laterally and horizontally extending stopper ledge 70 , 72 extending inward where the upper portion sidewalls meet the shoulder 68 . These ledges 70 , 72 prevent unintentional separation of the platens 18 , 20 from the frames 12 , 14 as explained below.
[0028] Referring to FIG. 7 , a bridge 74 spans from the front wall 62 a to the back wall 62 c at the height of shoulder 68 . The bridge 74 has a circular aperture 76 in the center. The bridge 74 and sidewalls 62 a - d cooperatively define two square openings 78 , 80 . The aperture 76 and openings 78 , 80 , respectively, receive pin 112 and towers 102 and 204 from the platen 18 or 20 (See FIGS. 8-10 ). The back wall 62 c has a pair of hinge brackets 82 , 84 to respectively connect to hinge brackets 85 , 87 on the lid 30 or 32 as shown on FIG. 2 .
[0029] While the frame 12 or 14 is shown with solid walls, it will be appreciated that as long as a frame piece operates to at least provide a distal bottom or top edge of the ink stamper so that the platen and stamp die can be positioned at particular distances from this edge for defining a marking and non-marking position, then such a frame still falls within the scope of the present invention. This distal edge is typically placed against the surface to be marked but need not be. Thus, the frame 12 or 14 may actually only cover a portion of the platens or may simply be made of structural beams and columns.
[0030] Referring to FIGS. 8 and 9 , platen 18 (and similarly platen 20 ) has four walls 86 a - d defining an open, rectangular, bottom end 88 (also referred to as the far end of the platen relative to its position on the handle 16 ) and a top wall 90 . The height of clips 92 (shown on FIG. 2 ) on the stamp die retainer 26 or 28 corresponds to the height of sidewalls 86 b and 86 d to provide a snug fit that locks the retainer to the bottom end 88 of the platens 18 or 20 .
[0031] As illustrated in FIGS. 8 and 9 , two resilient stopper tabs 94 , 96 extend upward from top wall 90 and have widened pointed tips 98 , 100 . The distance between tab 94 and tab 96 corresponds to the distance between stopper shoulders 70 and 72 on frames 12 and 14 so that tabs 94 , 96 must be squeezed slightly inward in order to mount the platen 18 in the corresponding frame. Once the tips 98 , 100 are placed interiorly of the shoulders 70 , 72 , the tabs can be released, and the platen will not disengage from the frame 12 or 14 unless the tabs 94 , 96 are squeezed again since the tips 98 , 100 will respectively engage the shoulders 70 , 72 blocking further motion of the platen toward the bottom end 60 of the frame.
[0032] As also illustrated in FIGS. 8 and 9 , platen 18 also has two chimneys or towers 102 , 104 extending upward from top wall 90 and are open at the top wall 90 in order to provide access to the back of a stamp die 22 or 24 sitting within a main chamber 89 of the platen 18 for reloading of ink. A horizontally extending locking rib 106 , 108 protrudes from opposite sides near the top of the two towers 102 , 104 . These ribs are snapped into grooves 54 or 56 on the handle 16 as shown on FIG. 12 .
[0033] With this structure in mind, it will be understood that each square opening 78 and 80 on the frame 12 or 14 (shown on FIG. 7 ) provides access to the upper portion of the frame for one of the towers 102 or 104 , and one of the stopper tabs 94 or 96 . It will also be understood that interior walls 44 , 46 of the handle 16 (shown in FIG. 3 ) are shaped to avoid, and in one embodiment abut, the two towers 102 , 104 . As explained above, the top edges 110 of the towers are pressed against the stabilizing fins 50 (shown in FIGS. 3 and 10 ) of the handle when the platens 12 , 14 are secured to the handle.
[0034] As shown in FIGS. 8 and 9 , platen 18 also includes a mounting pin 112 extending upward generally from the center of top wall 90 . The shaft 116 of the pin is “X” shaped as shown in FIG. 8A and has a diameter to fit through aperture 76 on the frame 12 . The top of the pin is shaped to receive a cap 114 (shown in FIGS. 2 and 10 ) that snaps onto the pin. For this purpose, the cap 114 has an annular inner rib 126 (shown on FIG. 10 ) for snapping into an annular groove 128 (shown on FIG. 8 ) near the top of pin 112 .
[0035] Referring to FIGS. 2 and 10 , a resilient member such as a coil spring 118 is wound around the shaft 116 of the pin 112 and is compressed between a bottom edge 120 of the cap 114 and a top surface 122 of the bridge 74 on the frame 12 or 14 . This structure biases the platen 18 away from the frame's bottom end 60 . In other words, each platen is biased to the “non-marking” position.
[0036] Referring to FIGS. 10-11 , in order to operate the ink stamper 10 , the lid 30 or 32 over the stamp die 22 or 24 with the desired stamp design is opened and the corresponding frame 12 or 14 is placed against the surface to be marked. The handle 16 is then pushed toward that end of the frame and the surface to be marked. This action moves the “marking” platen toward the open distal end 60 of the frame 12 or 14 on the marking end of the ink stamper (the “marking frame”) and overcomes the force of the spring 118 and compresses it. Once the mark is made and the handle 16 is released, the force of the spring 118 forces the platen back away from the frame end 60 and away from the surface that was marked.
[0037] While this marking action proceeds, both the platen 18 or 20 , spring 118 and the frame 12 or 14 on the opposite end of the ink stamper (the “non-marking” side) are pulled inward while maintaining their positions relative to each other (i.e. the spring on the non-marking side is not compressed or expanded since the non-marking frame is free to move inward with the non-marking platen).
[0038] While a single handle 16 is shown, it will be appreciated that multiple handles could be used, for example, by splitting handle 16 so that “half” a handle would move for either side while the other half a handle would remain still on the “non-marking” side.
[0039] It will also be appreciated that more than two platens and stamp dies can be attached to a single handle in a wheel type of configuration.
[0040] While the preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the appended claims.
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A two-ended ink stamper has at least one handle with at least two ends. A first frame and a second frame are provided, and each frame is disposed adjacent to a different one of the ends of the handle. Each frame extends in a different direction from the handle. At least two platens are respectively operatively attached to, and disposed within, one of the frames for selective movement within the frame between a non-marking position and a marking position. Each platen is secured to the handle and extends outward from a different end of the handle. Thus, moving the handle moves the platens relative to the frames and between non-marking and marking positions.
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This application is a continuation of application Ser. No. 08/050,729 filed Dec. 21, 1992, now abandoned, which in turn is a continuation of application Ser. No. 07/798,946 filed Nov. 27, 1991 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to a movement detection apparatus suitably applicable to remote sensing by a TV camera, a moving image compression apparatus, a vibration-proof camera for correcting a vibratory motion of camera, etc.
2. Related Background Art
There are various methods and means for detecting movement of camera or subject. An example of movement vector detection apparatus using an image is described in U.S. Pat. No. 3,890,462.
That Patent discloses a method in which a luminance difference or interframe difference is obtained at a pixel from two sequential images, a space gradient is computed in a frame, and a movement amount is gained by division of the gradients per block.
The following formulae explain the above operation, where α stands for a movement amount in the x-direction and β for that in the y-direction. ##EQU1##
In the formulae, b represents an operation block size and g(F, x, y) an image. A character F denotes a frame number and d a difference between two frames or a interframe difference. Space gradients are defined by ∂g/∂x=g x ' and ∂g/∂y=g y '.
This movement vector detection method has a problem in that the detection range of the movement amount is small, causing an extremely big detection error upon detection of a great movement amount. That is, a quick motion cannot be detected using a TV signal of a fixed frame rate.
FIG. 1 shows a simulation result of the movement detection operation applying the conventional method to an actual image.
The simulation assumptions are that a screen is composed of 512×512 pixels, and that a striped black and white pattern of 32 pixel period is photographed by a lens diameter of ten pixel circle of least confusion. A block size for the operation is 25 pixels.
As seen in FIG. 1, accurate detection of the movement amount is restricted within the actual movement of four to five pixels. Beyond the five pixel movement, the detection accuracy decreases so that detection values get away from the ideal characteristics. Moreover, in case that the actual movement amount is over eight pixels, the detection value becomes reduced. For example, at the twelve pixel actual movement, the detection value is about four pixels, which cannot be distinguished from the actual movement of four pixels.
Since the detection value becomes smaller upon greater actual movement, this apparatus shows a further greater detection error when calculating an acceleration or a difference per unit time between two movement amounts.
The detection range may be normalized by the pattern period λ of a subject. An accurately detectable range is between λ/4 and λ/6, presenting a theoretical limit of performance of the conventional method.
Below are listed prior applications and patents of the present applicant concerning apparatus detecting movement like in the present invention.
______________________________________Application or Patent Application date______________________________________U.S. Pat. No. 4788596Japanese Patent Appln.Laid-open No. 1-178916U.S. Ser. No. 880152 6/30/96U.S. Ser. No. 154078 2/9/88U.S. Pat. Nos. 5031049; 5,198,896; 4,939,685;5,012,270; 5,107,293; 5,164,835; and 5,128,768______________________________________
SUMMARY OF THE INVENTION
The present invention has a purpose to solve the above-described problem, providing a movement detection apparatus with a simple hardware structure, a wide movement detection range, and a high detection precision.
According to a preferred embodiment of the present invention to attain the purpose, there is disclosed a movement detection apparatus comprising first means for detecting a difference signal between first and second image signals, second means for integrating the difference signal detected by said first means, third means for detecting respective image signal levels of said first and second image signals when the image signals reach a predetermined level, fourth means for detecting a difference signal of plural detection results given by said third means, and fifth means for dividing said second means output signal by said fourth means output signal to detect a signal corresponding to image movement.
Another purpose of the invention is to provide a video camera with a movement detection apparatus realizing a wide movement detection range and a high detection precision.
According to another preferred embodiment of the present invention to attain the purpose, there is disclosed a movement detection apparatus comprising image pickup means for converting an optical image into an electric signal to output an image signal, first operation means for outputting a difference signal between first and second image signals output by said image pickup means at different times, detection means for detecting an image signal level when said first and second image signals reach an identical level, second operation means for operating a difference signal of plural detection results given by said detection means, and third operation means for effecting a predetermined operation on output signals of said first and second operation means to output a signal corresponding to image movement.
Still another purpose of the present invention is to provide a video camera apparatus with the above movement detection apparatus.
Other purposes and specific features of the present invention will be clarified by the following details and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram to show a movement detection property of a conventional movement detection apparatus.
FIG. 2 is a block diagram to show a structure of a movement detection apparatus of the present invention.
FIGS. 3A to 3D are drawings to illustrate a theory to detect a movement amount by the apparatus of the present invention.
FIGS. 4A to 4D are drawings to illustrate another theory to detect a movement amount by the apparatus of the present invention.
FIG. 5 is a diagram to show a movement detection property of the apparatus of the present invention.
FIG. 6 is a block diagram to show another embodiment of the movement detection apparatus of the present invention.
FIG. 7 is a drawing to show a movement detection property of the apparatus as shown in FIG. 6.
FIG. 8 is a block diagram to show the first example in which the movement detection apparatus of the present invention is applied to a vibration correction apparatus of a video camera.
FIG. 9 is a block diagram to show the second example in which the movement detection apparatus of the present invention is applied to a vibration correction apparatus of a video camera.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A movement detection apparatus of the present invention is described below with references to preferred embodiments thereof and accompanying drawings.
FIG. 2 is a block diagram to show a structure of an embodiment of the movement detection apparatus of the present invention.
In FIG. 2, 1 denotes an image signal output by a camera system comprising an image pickup element, 2 a frame memory to store the image, 3 an image output signal read out of the frame memory 2, 13 a subtraction circuit to compute a difference between the image signal read out of the frame memory 2 and the present image signal, 4 a luminance difference signal output from the subtraction circuit 13, 5 an integration circuit to integrate the input signal thereinto, 6 an output signal of the integration circuit, 7 a comparator, 8, 9 latch circuits to latch a luminance signal, 10 a subtraction circuit to compute a difference between the outputs of the latch circuits 8, 9, 11 a division circuit to perform a division of the outputs of the integration circuit 5 and of the subtraction circuit 10, 12 a movement detection signal output from the division circuit 11, and 14 an operation control circuit to control the latch operation in the latch circuits 8, 9 based on the output of the comparator 7 and the luminance difference signal 4, and to control the reset operation of the integration circuit 5 and other operation operations.
The frame memory 2 stores the image during a determined frame time. The subtraction circuit 13 effects the subtraction between the delayed signal 1, g.sub.(1), stored in the frame memory 2 and the present signal 2, g.sub.(2), to obtain the luminance difference signal 4.
FIGS. 3A-3D are operation explanatory drawings of the present apparatus, where the luminance signals only of an x-directional scan line are shown for convenience of explanation. In the drawings, signals 1, 3, 4, 6 correspond to those in FIG. 2.
FIG. 3A shows the signal 1, g.sub.(1), the right edge of which has a great luminance.
FIG. 3B shows the signal 2, g.sub.(2), the edge of which moved to the right.
In case of such edge movement, the superposed signals 1, 3 show the hatched region 20 corresponding to a change caused by the movement. Assuming that the region 20 is a parallelogram, the movement amount α corresponds to the base of the parallelogram. The movement amount α will be obtained by dividing the area of the region 20 by the height of the edge.
The movement detection apparatus of the present invention determines the movement amount based on the above theory.
In order to electrically obtain the area of the region 20, the luminance difference signal 4 is used, which is gained by subtraction of g.sub.(1) and g.sub.(2) at the subtraction circuit 13.
The luminance difference signal 4, as shown in FIG. 3C, is an electric signal of triangle or trapezoid shape, the area 21 of which is equal to that of the region 20. Then the luminance difference signal 4 is input into the integration circuit 5 for integration thereof, to obtain the signal 6 as shown in FIG. 3D. The signal 22 obtained is proportional to the area of the region 21.
Further, to obtain the edge height, a boundary is noted where the level of the luminance difference signal 4 becomes zero.
In FIGS. 3A-3D, x 0 is a point where the luminance difference signal 4 leaves zero and x 1 a point where it returns to zero. The luminance signals at those positions x 0 , x 1 are detected.
Actually in FIG. 2, the luminance signals at x 0 and x 1 are so obtained that the latch circuits 8, 9 are operated at respective timings when the comparator 7 detects the zero points of the luminance difference signal 4, and so that the latch circuits 8, 9 latch the respective luminance signal levels at the zero points.
In detail, the comparator 7 detects a pixel which has the zero luminance difference signal, to generate a pulse, and the latch circuits 8, 9 store the luminance signal data of the-image signal 1 in response to the pulse. Upon the latch, the latch circuits 8, 9 do not store the data of the identical pixel. The operation control circuit 14 controls the circuits 8, 9 so that they store the data at the ascending edge and the descending edge of the signal 4 discriminating them. In FIG. 2 the output luminance signals from the latch circuit 8, 9 are represented by 23, 24.
The subtraction circuit 10 computes a difference between the luminance signals 23, 24 to obtain the edge height of the signal 1. The signal is shown as 25 in FIG. 2. The dividing circuit 11 divides the signal value 22 by the signal value 25 to gain the movement signal 12 corresponding to the edge movement amount α as shown in FIG. 3B. At the same time, the operation control circuit 14 resets the integration circuit 5.
The above description refers only to the movement detection in the x-direction. A similar method is, however, applicable to the y-direction movement detection, for example, if the image stored in memory is vertically scanned for the read-out.
FIG. 3 illustrates an example of only one edge. Although actual images have more complex patterns, the apparatus of the present invention can detect the movement amount of such an actual image similarly.
FIGS. 4A-4D show signal conditions of such an image. FIG. 4A shows a wave shape of an image signal or luminance signal, and FIG. 4B a present image signal 1 and an image signal 3 delayed by a determined time by the frame memory 2. In FIG. 4B the image signal shifts right by the amount α, so that a region 20 is formed like a waved parallelogram. FIG. C shows a wave shape of a luminance difference output from the subtraction circuit 13, and FIG. 4D that of integration output from the integration circuit 5.
The region 20 of the thus-deformed parallelogram as in FIG. 4B may be approximated by a parallelogram if the movement amount α is small enough compared with a period λ of image. Then the above-described method provides an accurate movement amount α.
Since the integration circuit 5 is reset for each pulse of the comparator by the operation control circuit 14, the movement amount of the watching edge is detected accurately.
In case of further greater movement, the geometrical approximation to the parallelogram will be difficult to apply. FIG. 5 shows a simulation result using an actual image to show the limit. The conditions of calculation are the same as the conventional example as explained referring to FIG. 1.
According to a simulation, the detection using the present apparatus shows less detection errors, for example, twelve pixels of detection for ten pixels of actual movement against five pixels of detection therefor by the conventional method.
Also, while the conventional method revealed the extreme errors upon detection of acceleration for the movement amount over a quarter of the subject pattern period λ due to the tendency to reduce the detected value, the above-detailed apparatus of the present invention remarkably improves the errors.
Furthermore, if the subject size, the pattern period, and the circle of least confusion are known, the curve of FIG. 5 is uniquely determined. Storing the curve in a ROM table and adjusting the detection properties leads to further improvement of detection precision.
In the above example of an image, the accurate detection can be attained within one pixel error up to twelve pixels or three eights of the subject pattern period λ even if considering calculation errors.
As explained above, the movement apparatus of the present invention achieved a great improvement in detection properties compared with the conventional apparatus.
FIG. 6 shows another embodiment of movement detection apparatus of the present invention with further modifications. The apparatus of this embodiment allows the detection of the movement amount with high precision without knowing the pattern size of the subject.
In FIG. 6, 50 denotes the movement detection apparatus of the first embodiment as shown in FIG. 2, 51 an image band pass filter as is abbreviated hereinafter as BPF, 52 a lookup table as is abbreviated hereinafter as LUT, 53 an output signal of BPF 51, and 54 an output signal of the movement detection apparatus 50. As explained before, the apparatus. 50 of the present invention has a close relation between the space gradient of the image and the detection range. Conversely, if a necessary detection range is determined, a suitable space gradient is also determined. This apparatus extracts only necessary component of space frequency using BPF 51 in the case of an unknown pattern size of subject.
Setting α' as a maximum of the movement amount to be obtained, the space frequency f to be extracted is given by the following:
f=1/λ=k·1/α' (3)
The value of k is preferably about 3/8.
The BPF 51 must be a two-dimensional filter when detecting both the movement amounts in the x-and y-directions. It is preferable that the phase property of BPF 51 be nearly linear in the band area of the pass.
The operation of LUT 52 is as follows. If a single frequency of signal 53 is extracted, the detection property of the apparatus 50 is uniquely determined. A curve 61 in FIG. 7 shows a detection property after BPF processing with λ=32 pixels. LUT 52 has a reciprocal number of the coefficient of the curve 61 to correct the curve into a line. A curve 62 in FIG. 7 shows the detection property after the correction. The output over a determined detection value is clipped in this embodiment.
The detection property may be linearized using LUT 52 as explained. Also, a non-linear detection property may be employed for some uses.
The movement detection apparatus of the present invention is arranged as explained. Explained next is an embodiment in which the movement detection apparatus is applied to a vibration correction device of a video camera.
FIG. 8 depicts a block diagram to show the third embodiment in which the movement vector detection apparatus of the present invention is used for a vibration correction device of a video camera.
In FIG. 8, 101 is a photographing lens optical system, 102 an image pickup element such as a CCD or the like to output a photoelectrically-converted image signals of a subject image focused on an image pickup screen by the optical system 101, 103 a preamplifier to amplify the image signal output from the image pickup element 102 up to a determined level, 104 a preliminary processing circuit to apply AGC to the input image signal to hold a constant level thereof and to effect processing of gamma control and others, 105 an A/D converter to convert the input analog image signal into a digital image signal, 106 an image memory to store one field of the digital image signal output from the A/D converter 105, and 107 a memory control circuit to control an address and a write-in rate upon reading the image into the image memory and to control a read-out address and a read-out rate of the image upon reading the image out of the image memory 106. The memory control circuit is controlled by a system control circuit 109 as explained later.
Number 108 denotes a movement vector detection circuit to detect the movement vector of the image from the image signal, the inner structure and the operation of which are similar to those in the circuit as shown in FIGS. 2 and 4 and, needless to say, effect the digital signal processing.
Number 109 is the system control circuit, comprising a microcomputer, to totally control the present apparatus, to compute vibration correction information from the movement vector information operated in the movement detection circuit 108, to control the memory control circuit 107 based on the above operation result, and to shift, upon reading the image out of the memory 106, the read-out position or read-out address on the memory in the direction of vibratory motion to kill the vibratory motion.
Number 110 is a camera signal processing circuit to effect determined signal processing on the readout image signal from the memory 106 to convert the signal into a normalized image signal, and 111 an angle-of-view correction circuit, being controlled by the system control circuit, to correct an angle of view of the image read out of the memory 106. In detail, the vibration correction is attained by shifting the read-out position of the image on the memory, so that the read-out image has a smaller angle of view by the shift range in the memory than the input image read into the memory. Then-the angle-of-view correction circuit 111 effects magnification of angle of view and compensation of the image so that the image has the same angle of view as one before the vibration correction.
The signal after the view angle correction is converted into an analog image signal by a D/A converter 112, and then supplied to an unshown monitor of a video recorder, electronic view finder or the like.
By the above arrangement, the vibration correction is attained so that the amount of vibratory motion is detected by obtaining the movement vector using the embodiments as shown in FIGS. 2 and 6, and then so that a read-out address is shifted in the direction to kill the vibration amount.
FIG. 9 is a block diagram to illustrate another example of a video camera with a vibratory motion correction device using the movement vector detecting circuit of the present invention. The same components as in FIG. 8 have the same numbers, and are not explained further.
In FIG. 9, 201 is a variable vertical angle prism to correct a vibratory motion by varying the vertical angle or direction of the optical axis thereof. One example of the prism is an arrangement that silicone base liquid is sealed between two parallel glass plates to make variable the angle therebetween or vertical angle.
Number 202 is a camera signal processing circuit to output a normalized image signal converted from the output signal of the preamplifier, and 203 a system control circuit comprising a microcomputer to detect a direction and an amount of vibratory motion from the movement vector information supplied from the movement vector detecting circuit 108 and to compute an amount of driving of the variable vertical angle prism for the vibration correction. The correction information computed in the circuit 203 is supplied to the drive circuit 204, and an actuator 205 to vary the prism is driven in the direction and by the amount to kill the vibratory motion.
As in the embodiments, the vibration correction is attained so that the vibration amount is computed by detecting the movement vector from the image signal, and further so that the variable vertical angle prism is driven in the direction to correct the amount of vibratory motion.
In either of the above embodiments, a movement vector operation region is suitably and automatically set in response to a spatial frequency of the input image. This allows the elimination of a great error vector even in an area of undistinguishable pattern, which, in turn, leads to high space resolution with effective use of the space gradient information of the image. The detection precision may increase by eliminating from the operation region the sign changing area of the space gradient as a spacing between the detection blocks, since the time space gradient method is not well applied therein. Therefore, the vibration correction may be attained with high precision and secure operation.
As detailed above, the movement detection apparatus of the present invention with a simple structure may detect the accurate movement amount from an image at a high speed, and may provide more than two to three times the detection range as the conventional methods.
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A movement detection apparatus comprises a first circuit for detecting a difference signal between first and second image signals, a second circuit for integrating the difference signal detected by the first circuit, a third circuit for detecting respective image signal levels of the first and second image signals when the image signals reach a predetermined level, a fourth circuit for detecting a difference signal of plural detection results given by the third circuit, and a fifth circuit for dividing the second circuit output signal by the fourth circuit output signal to detect a signal corresponding to image movement.
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This application is a division of Application Ser. No. 253,567 filed July 6, 1981, now U.S. Pat. No. 4,377,577, which, in turn, is a continuation-in-part of Application Ser. No. 155,800 filed May 30, 1980.
The present invention relates to a method of preventing pregnancy. More specifically, the present invention relates to the use of calmodulin binding drugs as a means to prevent pregnancy after intercourse by injecting such drugs into the uterus.
Presently, there is no effective method or product known for preventing conception or pregnancy after sexual intercourse has occurred, especially after an hour or more has elapsed after intercourse. For the purpose of this application pregnancy is intended to be defined as the implantation of a fertilized egg to the uterus.
Currently, in cases of rape or other cases of intercourse where pregnancy is unwanted, other than using douches or other normally ineffective methods to attempt to prevent conception, the normal practice is to wait to see whether the signs of pregnancy occur and, if so, have an abortion if the pregnancy is to be terminated.
Drugs that are capable of binding with calmodulin only in the presence of calcium are known as calmodulin binding drugs. Psychoactive drugs constitute one class of calmodulin binding drugs. Other known calmodulin binding drugs are disclosed in this application.
DESCRIPTION OF THE INVENTION
The present invention comprises the use of calmodulin binding drugs to prevent pregnancy. The introduction of such drugs into the uterus can be accomplished by normal clinical methods, such as injection by way of the vaginal tract, through the cervix and into the uterus. Such treatment is quick and simple; at least as simple as the currently used procedure for PAP Smears. By introduction of an effective amount or concentration of one or a combination of calmodulin binding drugs into the uterus prior to the implantation of a fertilized egg to the wall of the uterus, pregnancy will be prevented. Calmodulin binding drugs in the uterus will either prevent conception, if it has not yet taken place, or embryonic development of a fertilized egg prior to and necessary for implantation. Since implantation normally does not occur for several days after conception, the present invention may be used effectively for a significant period of time after intercourse, perhaps up to three or four days later.
The present invention does not involve the killing of the sperm, but instead directly and specifically blocks the physiological process of conception and embryonic development. It has been shown in the past few years that there is a regulatory protein known as calmodulin, found in all cells of higher organisms and which is the key to the control of a wide variety of physiological processes. We have found that calmodulin is involved in triggering the activation of mammalian spermatozoa, a prerequisite to the fertilization process, as well as in triggering the early events of ovum development after fertilization has occurred. Calmodulin is a calcium binding protein, which means that when calcium is bound to the protein the resulting calcium-protein complex turns on a variety of cellular processes including spermatozoan or ovum activation. We have found that calmodulin binding drugs inhibit the calmodulin function, and, as a result, use of such drugs will prevent the activation of spermatozoa and will prevent embryonic development following fertilization.
Calmodulin binding drugs are drugs that will bind tightly to calmodulin only in the presence of calcium. The binding of these drugs to calmodulin results in the inhibition of calmodulin function.
The use of an affective calmodulin binding drug in the uterus to prevent pregnancy has a number of advantages. First, it is extremely effective since the specific binding of the drug to calmodulin would turn off spermatozoan or ovum activation and embryonic development and thus prevent pregnancy. Experimental evidence has demonstrated that the phenothiazine drugs penetrate the spermatozoan membranes within seconds and concentrate in the region of the cell occupied by calmodulin. Second, there will be no expected side effects since the drug would not be used internally and since low concentrations will be very effective. Third, the effectiveness of an application may last for hours due to the stability of these drugs.
Known calmodulin binding drugs include the following two classes of compounds. The first class includes, and is exemplified by the following compounds:
(a) 8-anilino-1-naphthalenesulfonate
(b) 9-anthroylcholine
(c) N-phenyl-1-naphthylamine
The second class of compounds includes, and is exemplified by the following compounds:
(a) N-(6 aminohexyl)-5-chloro-1-naphthalenesulfonamide
(b) N-(6-aminohexyl)-5-chloro-2-naphthalenesulfonamide
(c) N-(6 aminohexyl)-5-bromo-2-naphthalenesulfonamide
To accomplish the present invention the calmodulin binding drugs would be combined with an appropriate carrier medium, such as paraffin oil, foam carriers or jelly carriers.
A preferred embodiment of the present invention comprises a buffered two percent concentration of 9-anthroylcholine in paraffin oil, introduced into the uterus in sufficient quantity and under known methods within six hours after sexual intercourse has occurred and allowed to remain therein.
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The use of 9-anthroylcholine by injecting or introducing such drug directly into the uterus is disclosed as a means of preventing pregnancy after intercourse has occurred. Various means of introducing such drug are disclosed, such as by mixing such drug with jelly carriers, foam carriers, or paraffin oil.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a correction tape dispenser for laying down a strip or band of correction composition onto a surface, most usually paper, e.g. to cover markings thereon to facilitate the correction of a mistake.
2. Description of the Prior Art
There are known correction tape dispensers which have supply and take-up spools for the tape mounted within a case to rotate about parallel axes with the supply spool being coupled to drive the take up spool through a slipping clutch arrangement. The case may be adapted to be held directly in the hand of the user, or it may form a cartridge which is inserted into a re-usable outer housing. A length of tape extending between the spools is guided to pass out of the casing and around a tip having a relatively sharp edge which is used to press the tape against the surface onto which the correction strip is to be applied. The tape consists of a ribbon, e.g. of plastics or paper, on one side of which is carried a coating of the correction composition, this coating being on the outer side of the ribbon when it passes around the tip. In use, the device is held in the hand and the tip is pressed down onto the paper surface so that its edge presses the tape against the surface across the full width of the tape. The correction composition has an adhesive quality and has greater adhesion to the paper than its carrier ribbon, so that when the tip is displaced across the paper surface in a direction perpendicular to the tip edge, the tip slides with respect to the ribbon causing tape to be drawn off the supply spool. The consequent rotation of the supply spool rotates the take-up spool so that a substantially constant tension is maintained in the tape and the take-up spool reels in the spent ribbon over which the tip has passed and from which the correction composition coating will have been deposited onto the paper surface. In this way a continuous strip of the correction composition is laid down onto the paper, this strip having a length according to the distance travelled by the dispenser tip.
The known correction tape dispensers operate satisfactorily as far as laying down the correction strip is concerned. However, they do require some practice to ensure that during displacement of the tip its edge is applied correctly against the paper. To a large extent the difficulty of ensuring the correct orientation of the tip is due to the device having to be held in an unnatural attitude, especially when the spools are arranged with their axes parallel to the tip edge.
SUMMARY OF THE INVENTION
The present invention addresses the drawback of the prior art devices and provides a correction tape dispenser comprising a tip having an edge for pressing the tape against a surface, a portion of tape between supply and take-up spool being guided to extend around said edge, wherein the edge is inclined to the feed direction in which the tape is guided to the tip, and the tip includes guide means on either side of the edge for redirecting the tape so that the path of the tape around the edge between the guide means is in a plane substantially perpendicular to said edge and inclined to the feed direction.
The tip employed in the dispenser of the invention allows the dispenser to be held in an orientation similar to that in which a writing instrument is normally held, namely inclined forwardly and downwardly away from the person using it, preferably at an angle to the paper in the range of 45° to 75°. As well as enabling a more natural holding position, the dispenser can allow the tip to be more readily viewed as the case enclosing the spools, and the hand of the user, can be disposed so as not to impede the user's sight of the tip. Thus, the convenience of use of the dispenser may be a substantial improvement on the prior art devices. The tape guidance can be simplified by the supply and take-up spools having their axes perpendicular to a plane containing the tip edge and substantially parallel to the feed direction.
The guide means may comprise a linear edge around which the tape extends to bend the tape path and simultaneously twist the tape. In one embodiment such linear edges are defined on respective sides of the tip by parallel ridges separated by a slot. Alternatively, the guide means on at least one side of the tip may comprise a guide element, e.g. a lateral projection, around which the tip passes to define a bend in the tape path. Conveniently, the guide element maintains the tape at the bend substantially perpendicular to the tip edge, and the tape is twisted longitudinally through substantially 90° between the guide element and the tip edge.
To retain the tape in proper cooperation with the tip edge, tape retaining means may be provided adjacent the edge on one or both sides of the tip. The retaining means can be arranged to prevent unintentional disengagement of the tape from the tip edge by defining with the tip a substantially closed eye through which the tape passes. The tip edge may have extensions to reduce risk of the tape becoming displaced over the edge extremities.
A full understanding of the invention will be gained from the following detailed description of an embodiment and reference to the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a correction tape dispenser in accordance with the invention;
FIG. 2 is a perspective view of the dispenser in use, the casing being shown cut away to reveal the tip member;
FIG. 3 is a side elevation of the tip member;
FIG. 4 is a side elevation of the tip member and also showing the path of the tape to and from the tip edge;
FIG. 5 is a front elevation of the tip member;
FIG. 6 is a perspective view illustrating the tip region of a modified embodiment of the invention, the housing having been cut away to reveal relevant details of the tape feed path;
FIG. 7 is an elevation showing the internal parts of the dispenser of FIG. 6 ;
FIGS. 8 and 9 are views corresponding to FIGS. 6 and 7 , respectively, showing a second modified correction tape dispenser according to the invention;
FIG. 10 is a detailed perspective view of the tip edge portion illustrating one form of a tape retention device; and
FIGS. 11 to 15 are views similar to FIG. 10 showing alternative devices for retaining the tape in correct cooperation with the tip edge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The correction tape dispenser illustrated in FIGS. 1 to 5 of the drawings has case 1 in which are housed tape supply and take-up spools 2 and 3 . The spools are rotatable about their respective parallel axes and as well known in the art the spools are coupled by a slipping drive mechanism (not shown) whereby rotation of the supply spool 2 in response to tape 4 being drawn therefrom causes the take-up spool 3 to rotate to reel in the tape to prevent the tape becoming slack between the spools. The tape itself can be conventional having a layer of correction composition coating one side of a carrier ribbon.
The case is of generally rectangular configuration and is elongated with the spools being displaced relative to each other longitudinally of the casing. Mounted in the casing and protruding from the forward end thereof is a tip member 5 , the distal end of which defines an edge 6 by means of which the tape is pressed against the paper surface for transferring a strip of correction composition from the carrier ribbon onto the paper. A length of tape extending between the supply and take-up spools is guided to pass around the tip edge 6 . The guiding means include tape positioning means provided by posts 7 , 8 , 9 conveniently disposed at the inner or proximal end of the tip member, and a cooperating to define a first slot between the posts 7 and 8 for prepositioning the tape coming from the supply spool ready for delivery in a predetermined feed direction to the tip 10 , and a second slot between posts 8 and 9 for setting a fixed end position for the tape to pass away from the tip 10 in a predetermined direction parallel to the feed direction, before moving on towards the take-up spool 3 . In the illustrated embodiment the feed direction is substantially parallel to the axis of the case 1 , which may be desirable, but is not essential.
The tip member 5 is an integral plastics moulding and provides a tip 10 with a first portion and a second portion defining the edge 6 and at an angle to the first portion. The first portion comprises guide means in the form of two ridges 11 , 12 defining parallel rectilinear edges inclined to the tape feed direction. A narrow slot 14 is formed between the ridges. The tape being delivered from the supply spool 2 and extending between the tape positioning posts 7 and 8 enters this slot 14 having twisted through 90° in passing from the posts to the tip 10 so that the coating of correction composition faces inwardly away from the ridge 11 . From the slot 14 the tape passes over the edge of ridge 11 , from the inside to the outside surface thereof, and is thereby redirected to extend towards the tip edge 6 in a direction perpendicular to that edge. Having passed around the tip edge, maintaining contact with the tip surface, the tape extends perpendicularly to the edge 6 until it reaches the edge of the ridge 12 around which it then passes before undergoing a 90° twist and passing between the posts 8 and 10 . This path of the tape is clearly depicted in FIGS. 2 and 4 . It will be understood that the correction composition coats the outer face of the tape ribbon as it approaches the tip edge 6 from the ridge 11 . Furthermore this ribbon face is also directed away from the surfaces of the ridge 12 so that there will be no tendency for the tape to stick to the tip 10 even if there are traces of correction composition remaining on the ribbon after it has passed around the tip edge.
As may be best seen in FIGS. 3 and 5 , on either side of the tip, adjacent the edge 6 , are tape retaining means consisting of a pair of protruding guide wings 16 to assist in maintaining the tape along the correct path between the ridges 11 , 12 and the edge 6 . If required a pin 17 may be inserted to extend between the wings on one or both sides of the tip to provide a positive retention of the tape between the wings.
It will be appreciated that the geometry of the tip requires that the angle of inclination y ( FIG. 4 ) of the ridge edges to the tip edge direction, i.e. a straight line on which the edge lies, is substantially equal to half the sum of 90° and the angle of inclination x of the tape feed direction to the tip edge direction. As the case 1 ( FIG. 1 ) is elongated in the tape feed direction, the angle x is also the “writing angle” of the dispenser, i.e. the angle at which it is held in a downwardly and forwardly inclined orientation in use. A suitable “writing angle” would be in the range of 45° to 75°, preferably about 60°.
For laying down a strip of correction composition, the case of the dispenser may be held comfortably in the hand in essentially the same way as a conventional writing instrument would be gripped, that is mainly between the thumb and forefinger. The dispenser is held so that the tip edge 6 lies flat against the paper surface P, except that the tape 4 is interposed between the tip and the paper. The dispenser is then displaced across the paper in the lateral direction, normal to the tip edge 6 , as indicated by the arrow in FIG. 2 . Under the pressure exerted through the tip, the correction composition adheres to the papers surface and the tip slides along the tape ribbon causing fresh tape to be drawn from the supply spool 2 and laid down immediately in front of the moving tip while ribbon over which the tip has passed is drawn back into the case 1 and is reeled up onto the take-up spool 3 , having left the correction composition previously carried thereby on the paper. Thus, a continuous band of correction composition with a length corresponding to the distance travelled by the tip is laid down without demanding any specific dexterity on the part of the person using the tape dispenser.
Alternative embodiments of the invention are shown in FIGS. 6 and 7 and FIGS. 8 and 9 . Each of these dispensers is basically similar to the first embodiment and where the same reference numerals have been used in the drawings they denote corresponding parts. Each modified dispenser includes a case 1 housing tape supply and take-up spools 2 and 3 , the spools being coupled by a slipping clutch mechanism and the tape 4 consisting of a layer of correction composition coating one side of a carrier ribbon. Protruding from a forward end of the elongated case is the tip member 5 defining the edge 6 used to press the tape against the paper surface for transferring a strip of correction composition from the carrier ribbon onto the paper, a length of tape 4 extending between the supply and take-up spools being guided to pass around the tip edge. The tip member includes guide means for redirecting the tape so that the edge 6 is inclined in the feed direction in which the tape travels towards the tip member, and the correction tape dispenser has a “writing angle” of 45° to 75°, preferably about 60°, to the paper.
In the dispenser of FIGS. 6 and 7 , the tip member is attached to and conveniently integral with a plastics carrier frame which supports the spools 2 , 3 . The member 5 includes a tip 10 with an edge portion and a guide portion which is inclined to the edge portion and is generally L-shaped in cross-section to define a shoulder 21 at which the guide and edge portions meet. Fixed to or integral with the guide portion are guide means provided by a tape guide peg 22 , and by a ridge 12 defining a rectilinear edge inclined to the tape feed direction. On either side of the tip, near the edge 6 , tape retaining means are provided by a pair of wing projections 16 spaced apart by a distance equal to the width of the tape. The tape 4 passes forwardly from the supply spool 2 to the peg 22 around which it passes so that the tape then extends towards the edge 6 in a direction essentially at 90° to that edge. The tape section between the peg 22 and the edge of the shoulder 21 is twisted through 90° about its longitudinal axis. From the shoulder 21 , the tape passes around the tip edge 6 in a plane substantially perpendicular to the tip edge, and eventually reaches the ridge 12 across which it rolls over onto the first side of the tip member to pass on towards the take-up spool. The wing projections 16 serve to maintain the tape in correct alignment with the edge 6 .
In the construction illustrated in FIGS. 8 and 9 , the tip member 5 has tape guide means consisting a pair of opposed guide pegs 22 , 23 on opposite sides thereof, and the supply and take-up spools 2 , 3 are shown mounted to face in opposite directions although this is not essential. The edge portion of the tip is largely similar to that of the dispenser of FIGS. 6 and 7 , but has a more rounded or bulbous form opposite the edge 6 . The tape guidance is essentially the same on both sides of the tip member with the tape being twisted through 90° in passing from the peg 22 to the edge 6 and being twisted through a further 90° between the edge 6 and the peg 23 . With the guide means provided by the pegs 22 , 23 , the need for tape positioning means is eliminated as the pegs can accommodate the changes in tape path due to the tape diameter on the supply spool reducing, and the tape diameter on the take-up spool increasing, as the tape becomes used up.
In use the modified dispensers are held and moved across the paper exactly as described above in relation to the embodiments of FIGS. 1 to 5 . The modified tape guiding means have the advantage of reducing the area of contact between the tape and the tip member so that frictional resistance to tape advancement is diminished and smooth operation of the correction device thereby is enhanced. With a view to reducing friction still further the guide pegs could be equipped with or be replaced by rollers.
FIG. 10 illustrates in more detail the tape retaining means associated with the tip edge and consisting of the wings 16 and pin 17 which together with the tip form an eye through which the tape passes. FIG. 11 shows a modified construction in which a substantially closed eye is defined by retaining means consisting of opposed L-shaped projections 30 integral with the tip and between which a slot 31 is formed to enable the tape to be introduced laterally into the eye. FIG. 12 shows another modification in which the L-shaped projections 30 overlap, but are displaced along the tip to provide the slot 31 for insertion of the tape. In the construction of FIG. 13 , an eye for the tape is defined on each side of the tip by retaining part comprising a sleeve 32 surrounding the tip. The sleeve could be integral with the tip or be formed as an extension on the dispenser body or case. Preferably, however, the sleeve is a separate collar which can be pushed over the tip end after the tape has been correctly positioned around the tip edge. In the further modification of FIG. 14 , the tip 10 has an I-shape cross section to locate and positively define the eyes with the collar. Finally, in FIG. 15 the tip is equipped with extensions 33 to elongate the tip edge and reduce the chances of the tape becoming displaced over an edge extremity in use of the dispenser.
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In a correction tape dispenser, wherein a backing ribbon carrying a layer of correcting composition is fed from a supply spool ( 2 ) around the edge ( 6 ) of an applicator tip ( 10 ) used to press the tape against a paper surface (P) to transfer the layer of correcting composition onto the paper, and back to a take-up spool ( 3 ), a tape guide system ( 11,12; 22,23 ) is provided near the tip to redirect the tape, the tip edge ( 6 ) being at an angle to the feed direction so that the body of the tape dispenser may be held in a forwardly and downwardly inclined orientation similar to that in which a writing instrument is normally held.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under Section 119(e) to the U.S. Provisional Application No. 61/756,351, entitled, “Chemically Dissociating Working Fluid Engine and Method for Generating Power Without Natural Temperature Gradients”, filed Jan. 24, 2013, the contents of which are incorporated by reference herein in its entirety and for all purposes.
FIELD OF THE INVENTION
[0002] The devices of the present disclosures are novel types of heat engines, to include turbines, which take advantage of chemically reacting working fluid components to significantly improve thermal efficiency. When operated under select conditions, determined by a described method for optimization, the stated engines are shown to have superior thermal efficiency and work output per mole of working fluid per cycle compared to conventional engines of the same class operating over the same temperature range. Particular emphasis is given to the Stirling engine embodiment, as the calculations involved in theoretically optimizing the thermal efficiency of this embodiment are relatively simple and demonstrate the principles of the present invention in an intuitive manner.
BACKGROUND OF THE INVENTION
[0003] Heat engines convert thermal energy into useful work using differences in thermal energy between high temperature and low temperature thermal reservoirs. This is accomplished by causing a working fluid, which is typically a gas (but may be, for example, a vapor or supercritical fluid), to perform a thermodynamic cycle.
[0004] Such cycles are described by movement through the mathematical space of thermodynamic state variables (state space), resulting in a return to initial state space coordinates at the completion of a cycle. The variables for state space representation most typically used for engine analysis are pressure and volume, which are a pair of conjugate variables, jointly representing units of energy, where one variable is intensive (P) and one is extensive (V).
[0005] Accordingly, state space diagrams, which plot the path of cycles in state space, present a geometric method for calculating energy changes in the working fluid throughout the course of a cycle. State space diagrams, by convention and for simplicity in relating to real systems, plot intensive variables on the ordinate axis and extensive variables on the subordinate axis. An example is the Pressure-Volume (P-V) diagram. Integrating the area under each step of the curve on a state space diagram, moving in the appropriate direction, will provide the energy change for that step. In this manner, the magnitude of work invested in fluid compression is subtracted from the magnitude of work spontaneously evolved from fluid expansion, in order to yield the net useful work from the cycle.
[0006] When heating and cooling processes are involved in engine operation, it is common to employ regenerative heat exchangers to recover energy released from cooling fluid for use in simultaneous or subsequent heating of the working fluid. Heat regeneration serves to increase the thermal efficiency of a heat engine which, is defined by the ratio of net useful work performed by the engine to the net heat absorbed by the engine.
[0007] An example of practical engine embodiment is the Stirling engine. Stirling engines approximate a Stirling cycle, which includes (1) forced isothermal (constant temperature) compression at relatively lower temperatures, (2) isochoric (constant volume) heating, (3) spontaneous isothermal expansion at relatively higher temperatures, and (4) isochoric cooling. On a P-V diagram as depicted in FIG. 5 , this is equivalent to moving clockwise from the bottom right of the cycle.
[0008] For conventional Stirling engines, the heat absorbed by the engine is a combination of the heat required to maintain the temperature of the gas during isothermal expansion, and the heat required to increase the temperature of the gas. The heat input to the engine for increasing the gas temperature can be reduced by use of a regenerator. Regenerators are a variety of counter-current heat exchanger that use a physical substrate to store heat since working fluid flows only one direction through the regenerator at a time.
[0009] The expression for efficiency for Stirling engines, ε th , is described by Equation 1.
[0000]
ɛ
th
=
w
E
-
w
C
Q
E
+
(
1
-
ɛ
R
)
Q
V
+
Q
L
.
E
1
[0010] In this equation (Equation 1), for which all quantities are on a molar basis, W E is the magnitude of the expansion work, W C is the magnitude of the compression work, Q E is the heat absorbed during expansion, ε R is the energy efficiency of thermal energy recovery, Q V is the magnitude of the heat absorbed while the temperature is being increased, and Q L is a term accounting for unrecoverable losses, typically from lost work. In the ideal case, Q L is equal to zero, and Q E is equal to W E .
[0011] The ideal Stirling engine converts thermal energy to mechanical energy with isothermal work and contains a working fluid which follows the ideal gas law. Therefore, the magnitude of the work for fluid expansion or compression can be described by the well-known relation of ideal isothermal work (W), expressed by Equation 2, to the molar quantity of fluid (n), the gas constant (R), and the ratio of final volume to initial volume commonly referred to as a compression ratio (C).
[0000] | W|=nRT ln( C ) E2.
[0012] The net work (W NET ) performed is the difference between the magnitude of the expansion work at the heat source temperature (T H ) and magnitude of the compression work at the heat sink temperature (T C ), expressed in Equation 3.
[0000] W NET =nRT H ln( C )− nRT C ln( C ) E3.
[0013] For a theoretical ideal Stirling cycle, the heat absorbed by the working fluid from expansion is equal to the sum of the work performed and the change in internal energy of the fluid during isothermal expansion. The change in internal energy is equal to zero, in the ideal case. The heat absorbed during the isochoric heating step is a direct result of inefficiencies in thermal energy recovery. The total heat absorbed by the working fluid during isochoric heating is proportional to the sum of the total heat capacities of its i components (n i c i,v ) and the temperature change (dT) experienced. Therefore, the heat absorbed during isochoric heating (Q V ) can be written as shown below in Equation 4.
[0000] Q V =Σ i ∫ T C T H n i C i,v dT E4.
[0014] In the ideal limit, Stirling engines approach the currently recognized maximum limit on thermal efficiency for heat engines, known as the Carnot Limit. This limit, which applies to heat engines operating with a constant molar quantity of fluid, a thermal reservoir at a relatively higher temperature, T H , and a thermal reservoir at a relatively lower temperature, T C , can be described mathematically by Equation 5.
[0000]
ɛ
max
=
1
-
T
C
T
H
.
E
5
[0015] In this equation (Equation 5), ε max represents the maximum allowed efficiency, T H represents the absolute temperature of the high temperature reservoir, serving as a heat source for the engine and T C represents the absolute temperature of the low temperature reservoir, serving as a heat sink for the engine. Since the Carnot Limit depends only on temperature, the efficiency of conventional engines operating in the same temperature range will depend only on inefficiencies in design.
[0016] The present invention has primary application to the enhancement of heat engine efficiency. For practical purposes, the Stirling engine has been long regarded as the most efficient form of conventional heat engine. In the theoretical limit (including ideal heat regeneration), it can theoretically reach the Carnot Limit on engine efficiency.
[0017] In practice, there are a wide variety of embodiments of Stirling's engine concept. Kamen, et al. (“Stirling Cycle Machine”, U.S. Pat. No. 8,874,256) teaches a Stirling engine which makes use of two pistons in combination with a special rocking drive mechanism and crankshaft suitable for converting mechanical work into a form where it can drive an electric generator. Johnansson, et al. (“Control Valve for a Stirling Engine”, U.S. Pat. No. 8,534,063) teaches the use of a particular type of control valve within a Stirling device, in order to control leakage between working fluid flowing between control volumes, as well as for pressure balancing. Older prior art by Bland (“Stirling Cycle engine with Catalytic Regenerator”, U.S. Pat. No. 3,871,179—1975) teaches the use of a catalyst within the regenerator of a Stirling engine, in order to increase the number of moles of gas within the engine during heating of the gas, thereby enhancing thermodynamic efficiency and power output of the engine.
[0018] When applied to a Stirling cycle device, as one embodiment, the present invention, in contrast to Bland, produces additional moles of gas during the heating of the working fluid, without the use of a catalyst, but instead by incorporation of a working fluid that has a molecular dimer structure that reacts (by a shift in the chemical equilibrium of a reversible reaction) to increased gas temperature by dissociation into monomer gas molecules, in turn creating an additional number of moles of gas at higher temperatures. The dissociation reaction can be either single stage or multi-stage, depending on the operating temperature limits for the engine. Many aspects of the prior art may be retained and used within embodiments of the present invention, for example, the use of multiple pistons, heat regeneration, and control valves. Optimization of embodiments of the present invention must incorporate analysis and consideration of the properties of the chemically reacting working fluid, as well as analysis and consideration of the design issues associated with conventional engines. Additionally, the present invention may be applied to other forms of heat engines, such as particular forms of turbine engines, for example turbines approximating an Ericsson cycle.
BRIEF SUMMARY OF THE INVENTION
[0019] The invention disclosed herein comprises both devices and methods, wherein the specified method is utilized to optimize both the operating points and parameters of the device so that the object advantage is achieved.
[0020] The device of the present invention is a heat engine operated with a working fluid comprising chemical components that participate in one or more chemical equilibrium reactions. These reactions create a shift in the equilibrium concentration of the working fluid components according to temperature, resulting in an increased number of fluid particles at higher temperature. As a direct result of the increased molar quantity of working fluid, the device is capable of producing increased useful work from a thermodynamic cycle of the engine. When the device has a means of recovering energy from the shift in equilibrium, which occurs as the temperature is decreased, the present device can operate with increased thermal efficiency, as compared to conventional heat engines of similar design. Possible means of energy recovery may include, for example, heat exchange and/or the net production of useful work. The heat engine may be a piston engine, for example an engine executing a Stirling cycle, or a turbine engine which performs a suitable type of thermodynamic cycle, for example an Ericsson cycle.
[0021] In one embodiment, the present invention consists of an engine that executes a Stirling cycle, such engine comprising: one or more cylinders containing a working fluid capable of the required chemical reaction(s), and enclosing piston(s) that can perform work for compression of the working fluid, as well as extraction of useful work from working fluid expansion; a heat exchanger, typically of a counter-current variety, to include regenerators; and two thermal reservoirs, one operated at a higher temperature, corresponding to an operating point where the number of moles of gas has been substantially increased, and one operated at a lower temperature, corresponding to a point where the number of moles of working fluid is substantially less than that at the higher temperature.
[0022] For the Stirling engine embodiment, engine operating points and design parameters are chosen via a particular method, elsewhere described in this disclosure, in order to create a net efficiency gain, relative to that of a conventional Stirling engine. Increased efficiency is achieved when the engine is operated with particular concentrations of particular working fluid components, at particular compression ratios, and with select heat source and heat sink temperatures, which depend on the particular details of the selected working fluid components. Additionally, the heat exchanger/regenerator is designed for sufficient recovery, by the regenerative heat exchange process, of the extra energy required for accomplishing chemical reaction of the working fluid, so that a net increase in useful work output and engine efficiency is accomplished at the selected operating points and for the selected engine design parameters.
[0023] The method of selecting engine operating points and design parameters is key to achieving the object advantages of the present invention, i.e. an engine device, which has superior efficiency and useful work output as compared to conventional engines that do not utilize gases that undergo equilibrium reactions. The pressure and entropy of the working fluid of the device increase and decrease with temperature, to an extent not realized by conventional engines. The ratio of state and path variable values in the working fluid of the device to the same quantities in the working fluid of conventional engine devices, operating with the same molar concentration at the lowest temperature and pressure of the engine cycle, are subsequently referred to as relative properties, an example being relative entropy, and are considered “high” for values greater than one and “low” for values less than one. The changes in relative pressure and relative entropy are a direct result of temperature dependent changes in the molar quantity of fluid, reversibly accomplished by chemical reaction(s).
[0024] High relative pressure in the device at the higher temperature(s) of the cycle directly results in high relative work. Relative pressure is continually increased at the higher temperature(s) of the cycle by pressure dependent reaction during expansion, which results in high relative expansion work. Similarly, relative pressure, initially equal to one, is continually decreased at the lower temperature(s) of the cycle by pressure dependent reaction during compression, which results in low relative compression work. The high relative entropy at the higher temperature(s) of the cycle directly results in higher relative heat absorption, which has a negative effect on thermal efficiency.
[0025] The device of the present disclosures can be optimized for thermal efficiency by the method of the present disclosures. This optimization method considerers the lower and higher temperature limits of the engine cycle, the efficiency of thermal energy recovery in the form of work or thermal energy regeneration, the volume or pressure ratio(s) for working fluid expansion and compression, and the molar concentration of fluid components including components used to control chemical reactions. The described method examines mathematically, sources of increased or decreased efficiency as compared to conventional engines, including enthalpy or enthalpies of reaction, irreversible losses from enthalpy or enthalpies of reaction during working fluid expansion, and calculation of work with a variable molar quantity of fluid.
[0026] Additionally, the method of the invention considers the impact of recovering thermal energy, including the enthalpy or enthalpies of reaction(s), by use of heat exchangers or useful work production. The described method for optimization also can include consideration of mechanisms for changing the upper and lower temperature operating bounds of the engine cycle in order to increase efficiency and/or power.
[0027] The method of the invention requires consideration of both the shift of reaction equilibrium with temperature, as well as reaction kinetics. For example if the rate(s) of chemical reaction(s) are not rapid enough, efficiency gains over conventional engines will not be accomplished. For described embodiments of the device, the described method takes an equilibrium solution approach to the determination of the extents of reaction, since the involved reactions are known to occur with sufficient rapidity, so as to be limited only by heat transfer under normal engine operation.
[0028] The method of the invention must deal with the issue of required recovery of invested heat energy using heat exchange/regeneration or net useful work production. A particular embodiment of the device using the Stirling engine architecture, allows for recovery of energy for inducing chemical reaction(s) from the released thermal energy of the cooling fluid by use of a regenerator. It is necessary to achieve high thermal regeneration efficiency (including loss effects from regenerator ineffectiveness and viscous energy dissipation) in order for the device to exceed conventional engine efficiencies, since typical enthalpies of reaction are large, when considering the quantity of net useful work generated from each cycle. The method of the invention allows determination of the required regenerator efficiency so that additional regenerator heat load requirement can be incorporated as a significant design consideration. The required efficiencies necessitate the use of either a larger or an atypical regenerator (such as modified recuperators), to accomplish the same efficiency of thermal energy recovery. The use of atypical regenerator designs is preferable, owing to the loss of swept volume from increased regenerator size. It is also possible to compensate for the larger required size of the regenerator by use of valves, for controlling the flow of working fluid during the expansion and compression steps of the engine cycle.
[0029] From the method of the invention it is straightforward to mathematically extend the operating principles of the present device, described in the present disclosure for the Stirling engine embodiment, to include the particular case of an Ericsson turbine embodiment, thus verifying that the heat engine device of the present disclosures may be implemented with turbine components.
[0030] While classical turbines operate adiabatically, it has been shown that isothermal work for the Ericsson cycle can be approximated by use of interheaters and intercoolers between adiabatic turbine stages for the “isothermal” expansion and compression steps, respectively.
[0031] For the case of a turbine embodiment, the present invention comprises a turbine engine operated with a working fluid comprising chemical components that participate in one or more chemical equilibrium reactions, which occur in response to an increase in working fluid temperature, resulting in an increase of the number of gas particles (moles), typically approximating an Ericsson cycle, further resulting in increased work output from the engine as well as increased engine efficiency, as compared to similar conventional turbine engines that do not use such type of working fluid. Such embodiment additionally incorporates a heat exchanger, typically in the form of a recuperator, for recovery of energy invested for inducing chemical reaction(s), from the released thermal energy of the cooling fluid.
[0032] With regard to the utility of the device, the objective is to create an increased ability to generate additional mechanical, electrical, or other forms of power, from thermal energy sources, with higher efficiency than with conventional heat and/or turbine engines. Achieving this objective creates utility for the invention, as this capability increases the utility of available energy resources. The device of the present disclosure is also capable, in particular embodiments, of transforming heat at moderate and low temperatures into useful work, thus providing unique utility for the market in “waste” heat regeneration.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0033] The accompanying drawings, which are incorporated into, and form a part of, the specification, illustrate both the physical principles and a representative embodiment of the present invention. When the drawings are combined with the description, they serve to explain the invention so that it can be understood by one with ordinary skill in the art. The drawings are meant only for the purposes of illustration and explanation and are not meant to be construed as limiting the invention. In the drawings:
[0034] FIG. 1 presents a representative set of curves which serve to illustrate the dissociation of one particular working fluid, Dinitrogen Tetroxide (N 2 O 4 ), as gas temperature is raised at constant volume. Each curve represents one chemical component involved in the two dissociation reactions. The majority of the first dissociation reaction occurs at relatively lower temperatures and the majority of the second reaction occurs at relatively higher temperatures. The quantity, measured in moles, of each component are shown versus absolute temperature, measured in Kelvins. Note that the first dissociation reaction, occurring at lower temperatures, essentially is complete, (1), before the second reaction occurs, and that at higher temperatures, the molar quantity of NO 2 begins to decrease as it dissociates into NO and O 2 .
[0035] FIG. 2 presents a calculated value for the total quantity, measured in moles, of the above-mentioned working fluid as a function of Kelvin scale temperature, for two different initial concentrations as measured in units of molarity. This figure can be used, for example, to illustrate the effect of compression ratio on the quantity and variation of working fluid molarity versus temperature. Point ( 1 ) denotes the curve with the relatively lower initial concentration and point ( 2 ) denotes the curve with an initial concentration seven times higher than the molarity of gas used in the curve denoted by point ( 1 ). Note that lower initial concentration results in an increased slope of molarity versus temperature in the temperature ranges relevant to chemical reaction. Point ( 3 ) demonstrates that at the point where the first stage of chemical dissociation is complete, the dependence of dissociation on initial concentration, and therefore compression ratio, is relatively smaller than at other temperatures.
[0036] FIG. 3 is a diagram of the modified operation of a Stirling Cycle for the case of a particular embodiment of the present invention, where the working fluid is chosen to be a gas which dissociates as temperatures is raised. The diagram also illustrates the high temperature and low temperature thermal reservoirs, which are utilized in a conventional heat engine.
[0037] FIG. 4 presents one representative embodiment of the present invention which makes use of two cylinders containing movable pistons, regenerative heat exchanger, high and low temperature thermal reservoirs. The heat exchanger ( 8 ) shown in the figure is a rotating disk countercurrent exchanger, modified for use in a Stirling engine consisting of twin, synchronized cycles where the two cycles are completely out of phase with each other.
[0038] FIG. 5 presents two state-variable cycle curves with the variables chosen as Pressure (P) and Volume (V). In the diagram, the larger area contained within the curve in P-V space bounded by the solid line denoted by point ( 1 ), serves to illustrate the larger amount of work generated per cycle with a representative device that embodies the present invention, as compared to the amount of work generated by a conventional Stirling cycle engine that does not use a chemically dissociating gas. The work per cycle of the conventional Stirling engine is equal to the area of the curve bounded by the dotted line, which is seen to be less that the area contained within the solid line curve.
[0039] FIG. 6 shows a calculated comparison of estimated absolute engine efficiency in units of percent, for converting heat energy to useful work for both the present invention (solid curve), and the conventional Stirling engine, which does not make use of a dissociating working fluid. The calculation performed was for the one representative embodiment. The comparison serves to illustrate the utility of the present invention in terms of a significant advantage in engine efficiency that results from employment of the principles of the present invention. The comparison is done as a function of Kelvin scale temperature of the high temperature thermal reservoir.
[0040] FIG. 7 presents a relative engine efficiency comparison between the present invention, indicated by the solid curve, and that of the conventional Stirling cycle engine, indicated by the dotted curve, as a function of the Kelvin scale temperature of the heat source, for the one particular embodiment. Both sets of data are normalized to the performance of the conventional Stirling engine efficiency. Therefore the conventional engine has a relative performance of unity at all temperatures. This comparison serves to illustrate that the peak advantage of the present invention can be significant. For example, the peak advantage, denoted by point ( 1 ), for the representative embodiment is seen to be a 30% improvement relative to a conventional Stirling engine. However, this diagram also serves to illustrate that the device does not produce improvement over the entire temperature range (points ( 3 ) and ( 4 )), meaning that a method of optimization, as described within in the specification of the present invention, is required in order to produce a useful improvement in thermal efficiency by selecting operating parameters for the present device. This present figure also serves to demonstrate that there may be multiple temperature ranges where the present device provides an advantage over conventional engines by measure of thermal efficiency. There are two ranges of such advantage in the present figure, denoted by points ( 1 ) and ( 2 ).
DETAILED DESCRIPTION OF THE INVENTION
[0041] The present disclosures describe a novel heat engine device exploiting a working fluid predisposed to reversible increases in molar fluid quantity, in response to an increase in temperature, by use of one or more chemical reaction(s), to produce additional useful work, with limited additional energy losses, resulting in significantly higher thermal efficiencies compared to conventional engines. Gains in efficiency over conventional engines by the present device are achieved only under select conditions, described by the method of the present disclosures. The present method for optimization considers concentrations of working fluid, compression ratios, and the temperatures of the heat source(s) and heat sink(s). It is found necessary to recover a majority of the energy for accomplishing reaction of the working fluid in order to achieve a gain improvements in efficiency as compared to conventional engines. This can be accomplished by use of regenerative heat exchange or evolved work.
EXAMPLE EMBODIMENT
[0042] The construction and principles of operation of the present invention are explained herein with reference to one embodiment that is presented in the diagrams of FIG. 3 and FIG. 4 . The components of the engine as presented in this embodiment will be familiar to one with knowledge of conventional Stirling cycle engine construction. The selected embodiment described is meant only to illustrate a means of realizing the present invention and is in no way meant to describe all methods by which a device which embodies the invention might be constructed. FIG. 3 presents the thermodynamic stages of operation involved as the device performs a Stirling cycle using a dissociating gas as working fluid. A detailed description of the chosen embodiment requires reference to both FIG. 3 and FIG. 4 .
[0043] FIG. 4 shows the construction of a two-cylinder embodiment, which may be one module of a larger number of cylinders within an engine. The engine embodiment as shown in FIG. 4 is in part comprised of two cylinders (labeled as 1 and 6 in FIG. 4 ), each containing the selected working fluid (N 2 O 4 for this embodiment), and each having an associated piston and actuator or piston arm (labeled 2 and 7 in the diagram of FIG. 4 ). During a cycle, one cylinder and piston arrangement performs compression of the gas at low temperature ( 1 ), and one extracts work from expansion of gas at high temperature ( 6 ). The cold and hot temperatures T C and T H are defined by the temperatures of two thermal reservoirs, as shown in FIG. 4 . Other features of the device as shown in FIG. 4 , are optional valves, actuated by the engine or flow of the working fluid, (e.g. 3 and 5 ) for control and direction of the working fluid within the device, tubes for connecting the piston cylinders ( 4 ), and a regenerative heat exchanger through which the working fluids from each cylinder exchange heat ( 8 ). The hot gas is mostly cooled as it moves from the expansion cylinder through the regenerator to the compression cylinder, while the cool gas is mostly heated as it moves through the regenerator from the compression cylinder to the expansion cylinder. Upon execution of the heating/expansion and cooling/compression operations in each cylinder, respectively, the working fluid from each flows back to the other cylinder through the regenerator, completing the cycle.
[0044] The operation of the present engine is step-wise and described thus: Referring to FIG. 4 , cold working fluid in the compression cylinder at point ( 1 ) is compressed by the piston/arm arrangement ( 2 ) while hot working fluid in the expansion cylinder at ( 6 ) expands, performing work. Heat (Q C in FIG. 4 ) is transferred from the compression cylinder during the process to maintain the gas at constant temperature (T C ). Thermodynamically, this operation corresponds to the steps in FIG. 3 , where the dimerized working fluid ( FIG. 3 , 1 ) is cooled and compressed ( FIG. 3 , 2 ).
[0045] Referring again to FIG. 4 , as we continue to describe the operation of the engine, the working fluid next moves through the valve system ( 3 ) and into the regenerator ( 8 ) where heat exchange takes place. The working fluid then moves through the valve system at ( 5 ) into the expansion cylinder ( 6 ) where it is heated and allowed to expand within the cylinder against the piston, performing useful mechanical work, which is collected ( 7 ).
[0046] Thermodynamically, this next series of steps corresponds to the constant-volume (isochoric) heating (point 4 at FIG. 3 ) and dissociation of the working fluid at (point 5 in FIG. 3 ), followed by isothermal expansion (point 6 in FIG. 3 ). The cycle as described above repeats, with gas exchange occurring between the two cylinders occurring at each half-cycle point.
[0047] Optimization can be accomplished using a detailed thermodynamic model, to calculate the expansion and compression work, and heat required or produced at each stage of the cycle, inclusive of the thermodynamic effects of chemical reactions. For this reason, a considerable amount of information on the correct modeling of these effects is included herein, as a careful analysis of any particular embodiment of the present invention is required, in order to select appropriate operating points and design parameters for the device.
[0048] FIG. 3 and FIG. 4 do not illustrate materials or devices used to control heat flow from the high temperature thermal reservoir of the engine and/or to the low temperature thermal reservoir of the engine, however a particular embodiment may contain this element. Similarly, valves are not necessary and additionally, other mechanisms may be substituted for valves in the control of gas exchange within the cycle.
Method for Optimizing Device Efficiency Via Operating Point and Design Parameter Selection
[0049] The present invention involves a complex interaction of classical engine thermodynamics as well as (potentially complex) reaction equilibrium. For an embodiment of the present invention to successfully achieve efficiency advantage over conventional Stirling cycle engines, a method has been developed to project engine efficiency as a function of the selected working fluid, operating temperature range, and select engine design parameters. This method is described herein.
[0050] The relative molar quantity, α, can be expressed by Equation 6, where n 0 is the net quantity of fluid existing previous to progression of reactions (measured in moles). ν is the stoichiometric matrix, with reactions listed in rows and components listed in columns. Components of the stoichiometric matrix are negative for reactants and positive for products. ξ is the extent of reaction vector, with reactions listed in columns. The elements of ξ range from zero, indicating no reaction has occurred, to one, indicating that the reaction is complete. At least one extent of reaction for the described reactions is required to be temperature dependent, resulting in an increase in a with an increase in temperature, within at least one temperature range within the range of temperatures experienced in the present device. The temperature dependence of ξ and α is a direct result of the temperature dependence of the chemical potentials for the components of the working fluid.
[0000]
α
=
n
0
+
ξ
v
n
0
.
E
6
[0051] The molar quantity (n) of a working fluid with temperature-dependent relative molar quantity α is given by Equation 7. The quantity α can be used mathematically the same way for all chemically reactive working fluids, including fluids undergoing a dissociation reaction.
[0000] n=αn 0 E7.
[0052] An intuitive presentation of the principles of operation for the device is offered by the Stirling engine embodiment, operating with a chemically dissociating gas. For this particular embodiment, both an intuitive analysis and a detailed analysis are disclosed, which form an embodiment of the method presented herein. The intuitive analysis of the present device embodiment is presented first. For this analysis, the ideal theoretical Stirling cycle is considered, operating with an ideal gas.
[0053] For the ideal analysis, it is assumed that α is constant during isothermal expansion, since operating conditions can be picked such that pressure driven dissociation changes are small. For example, if all relevant reactions are essentially complete, then there will be no additional reactions, and α will be constant. It is easily seen that the pressure of the gas, expressed by Equation 8, is larger for the described working fluids than for gasses with constant composition.
[0000]
P
=
α
(
n
0
R
T
V
)
.
E
8
[0054] Equation 8 can be integrated with respect to volume, by anyone with ordinary mathematical skill, to calculate the ideal work for fluid expansion and compression. The magnitude of the work (W) of the ideal analysis of the present embodiment is described by Equation 9, where T H is the upper temperature limit of the cycle, T C is the lower temperature limit of the cycle, and C is the volumetric compression ratio.
[0000] | W|=n 0 (α T H −T C )ln( C ) E9.
[0055] It can clearly be seen from Equation 9 that the ideal work for the present embodiment is relatively higher than conventional engines operating with the same initial conditions but without a chemically reactive working fluid. This gain in useful work is a direct result of the increased molar quantity of fluid at the higher temperature reservoir, which multiplies the isothermal expansion work.
[0056] The thermal efficiency, ε th , of an ideal cycle Stirling engine operating with a reacting working fluid is given by Equation 10, where ε R is the energy efficiency of heat recovery from the regenerator, in reference to the heating requirements at the high compression isochoric step, and Q v is the molar heat input required for constant volume heating, including all relevant enthalpies of reaction for the working fluid.
[0000]
ɛ
th
=
(
α
T
H
-
T
C
)
ln
(
C
)
α
T
H
ln
(
C
)
+
(
1
-
ɛ
R
)
Q
v
+
Q
L
.
E
10
[0057] This expression can be simplified to the empirical form given by Equation 11, where β is the effective degree of dissociation, which is a function of the theoretical degree of dissociation and the irreversible losses from reaction during isothermal expansion, and C U is an empirical measure of the efficiency of mechanical and heat exchange components.
[0000]
ɛ
th
=
C
U
(
1
-
(
1
β
)
T
C
T
H
)
.
E
11
[0058] Equation 11 is an empirical limit of efficiency, demonstrating the principle of operation for the device of the present disclosures. Note that the inefficiency of the engine is nonlinear with the temperature ratio, unlike conventional engines. For specific cases, a more realistic model can be used.
[0059] The present invention incorporates a detailed method for determining feasible, and ultimately optimal, engine design parameters as well as operational parameters according to the selected form of embodiment. This method is described herein. The method incorporates an analysis of chemical reaction thermodynamics and kinetics, as well as engine thermodynamics, calculated in an iterative fashion, to derive performance (efficiency) corresponding to set of parameter choices, with such performance data being further analyzed in order to search over feasible solutions for those that produce an engine design having optimally enhanced efficiency.
[0060] There are two stages of chemical dissociation for the gas dinitrogen tetroxide (N 2 O 4 ), given by Equation 12. Both forward reactions for this reversible equilibrium system are endothermic and thus require heat input to proceed.
[0000] N 2 O 4 2NO 2 2NO+O 2 E12.
[0061] It can be seen that, for a one molecule basis, dinitrogen tetroxide dissociates into two molecules of nitrogen dioxide (NO 2 ) in the first reversible reaction, acting to double the initial molar quantity of fluid. In the second stage, the two molecules of nitrogen dioxide dissociate into two molecules of nitric oxide (NO) and one molecule of oxygen, further multiplying the molar quantity of fluid by 1.5, for a total multiplication factor of 3 as compared to the pre-reaction state. It is found that both described reactions occur with sufficient rate that they are limited under practical circumstances by the rate of heat transfer to and from the working fluid by the various components of the present device.
[0062] Heating at constant volume, as opposed to constant pressure, will cause the equilibrium of each reaction stage to tend more towards the reactants in order to resist the increase in pressure created by the increase in the molar quantity of fluid as a result of the reaction, due to Le Chatellier's Principle. Consequently, heating at the high compression limit on volume in the device of the present disclosures will cause a greater shift in equilibrium with temperature in the applicable temperature range for the reaction than cooling at the low compression volume limit. Therefore, unless all stages of reaction are complete at the low compression volume limit and high temperature limit of the Stirling cycle, there will be more heat released during cooling of the gas phase working fluid as compared to the requirements for heating the gas. This effect is beneficial for heat regeneration, as it ensures an excess supply of heat to the regenerator, but implies that unrecoverable thermal energy losses from shifts in reaction equilibrium from pressure changes must occur during isothermal expansion.
[0063] At a typical room temperature and atmospheric pressure (e.g. 293 K and 1 Bar), the first stage of the reaction is partially complete, as suggested by curve 1 of FIG. 2 . As a result of this, compression at room temperature will cause the equilibrium of the first reaction stage to shift to the left of the expression, and will therefore cause the pressure to drop relative to a nonreactive gas due to the reduction in molar fluid quantity. If a quantity of the compressed gas mixture is heated at constant volume, the first reaction stage will be nearly complete at approximately 550 K. At higher temperatures, the equilibrium of the second reaction stage is substantially affected.
[0064] As a result of the first reaction stage being complete and the second stage having not yet occurred, the local minimum for irreversible losses from reactions driven by temperature and pressure changes occurs approximately at the maximum mole fraction of nitrogen dioxide (approximately 550 K). Irreversible losses from undesired reaction are the primary reason for experiencing a local maximum of efficiency around 550 K, and efficiencies less than that of conventional engines within a higher subsequent temperature range, with the present device embodiment. Irreversible losses from the second reaction stage can be partially mitigated by dilution with oxygen in order to shift the reaction equilibrium to the left of the expression. However, this will also cause a decrease in efficiency gains for a particular upper and lower temperature limit of the engine cycle, due to the reduction in the molar quantity as compared to the molar quantity of fluid at the low temperature, low compression limit. Therefore, there will be an optimum dilution with oxygen to achieve maximal efficiency for a particular set of upper and lower cycle temperature limits. A further region of increased efficiency is achieved only after the second stage of reaction is nearly complete.
[0065] Another important design consideration for the present embodiment is the relatively high boiling point for the gas N 2 O 4 , close to room temperature and atmospheric pressure. As a result, isothermal compression of fluid from STP will cause liquefaction, which is undesired, since vaporization of the liquid N 2 O 4 will require additional heat input, and the liquid will make energy recovery with a regenerator much more challenging. Dilution to reduce the partial pressure of N 2 O 4 will also reduce relative efficiency gains over conventional engines. Therefore, it is desired to reduce the initial concentration (and thus the pressure) of fluid at the low compression, low temperature input, or to increase the lower bound on temperature, or, preferably, to reduce the compression ratio. While a reduction in fluid concentration will affect work output per cycle, it will have less effect on power generation, since the required heat transfer is also reduced, so the cycle can be implemented at a faster rate. In a practical version of the present embodiment, there will be an optimum tradeoff between the stated design parameters, for reducing liquefaction, that can be calculated or measured by one skilled in the appropriate arts and sciences.
[0066] To quantify the analysis of the present embodiment, Stirling cycle can be analyzed by the present method as a combination of nonideal isochoric heat exchange and nonideal isothermal work. Analysis of both types of processes require a solution for chemical equilibrium, an equation of state, and thermochemical property data in addition to selected operating parameters in the form of lower cycle temperature (T C ) in Kelvins, upper cycle temperature (T H ) in Kelvins, initial fluid concentration (M 0 ) in moles per cubic meter, and compression ratio (C) as a dimensionless number greater than one.
[0067] To calculate equilibrium, it is necessary to minimize the Gibbs free enthalpy for the working fluid system. The contribution to free enthalpy (ΔG f,i 0 ) from each component (i) is calculated from the absolute temperature, and entropies (ΔS i 0 ) and enthalpies (ΔH fi 0 ) of formation, as in Equation 13.
[0000] Δ G f,i 0 =ΔH f,i 0 −TΔS i 0 E13.
[0068] The contribution of pressure to the free enthalpy must also be considered. Since the pressure component of the free enthalpy term depends on the extents of reaction, an iterative search method must be used, beginning with a reasonable guess. The iterative search method used by the present embodiment of the disclosed method for optimization is a gradient descent algorithm including the physical constraint of conservation of mass (moles) for each species (n i ) by means of Lagrange multipliers (λ k ), where a ik is the number of atoms of element k in species i. The constraint is given by Equation 14, where A k is given by Equation 15 with n 0,i equal to the initial molar quantity of species i.
[0000] λ k (Σ i a ik n i −A k )=0 E14.
[0000] A k =Σ i a ik n 0,i E15.
[0069] The reasonable guess for the extent of reaction can be determined by means of an equilibrium coefficient (K C ), given by Equation 16 for the first stage of dissociation, where ν i is the stoichiometric coefficient for component i. As a very good approximation, Equation 16 has a valid closed form solution close to room temperature and atmospheric pressure.
[0000]
K
C
=
exp
(
∑
i
v
i
Δ
G
f
,
i
0
R
T
)
.
E
16
[0070] The extent of reaction (ξ) for the first stage of reaction depends on the equilibrium constant in this particular case by Equation 17, which can be solved by anyone with ordinary mathematical skill or with a root finder computer program.
[0000] (4 M 0 )ξ 2 +( K C )ξ− K C =0 E17.
[0071] The gradient descent algorithm incorporated into the present embodiment of the disclosed method solves Equation 18, with R equal to the commonly known gas constant, P i equal to the partial pressure of component i, P o equal to the reference pressure for the chemical component thermochemical data (1 Bar in most cases), and φ i equal to the fugacity coefficient for each component, calculated based on the equation of state (approximately equal to 1 for most gases).
[0000]
Δ
G
f
,
i
o
+
R
T
ln
(
(
n
i
∑
i
n
i
)
(
ϕ
i
∑
i
P
i
P
o
)
)
+
λ
k
(
∑
i
a
i
k
n
i
-
A
k
)
=
0.
E
18
[0072] For the analysis of the present device embodiment, the present embodiment of the disclosed method for optimization uses the Peng-Robinson equation of state, which depends on the critical temperature and pressure and acentric factor for each component. The entropies and enthalpies of formation are calculated from data from the National Institutes of Standards and Technology (NIST) WebBook using the Shomate Equation as well as provided data.
[0073] The presently embodied method makes use of a Proportional-Integral Controller for the gradient descent algorithm, and an additional constraint on the multidimensional iterative step in molar quantity for each component, so as to maintain the proper reaction mechanism. It should also be noted that a practical engine embodiment will proceed only to the equilibrium defined by the internal temperature and pressure (dependent on compression ratio) of the engine, which may be limited by heat transfer. In the present analysis, a theoretical cycle is considered, where temperature and compression ratio are known.
[0074] The presently embodied method uses the method for calculating equilibrium in a simulation, which can be performed to calculate isothermal work (W S ) per initial basis mole of working fluid at the low compression, low temperature limit of the cycle. This is accomplished by integrating the partial pressure (P i ) given by an equation of state for each component of the working fluid with respect to volume (V i ), from an initial specific volume (per basis mole at initial conditions) of V 0 to a final specific volume (per basis mole at initial conditions) V f and summing the result, as described by Equation 19.
[0000] W S =−Σ i ∫ V 0 V f P i dV i E19.
[0075] The heat absorbed from the high temperature thermal reservoir (W S,2 ) is the sum of the isothermal work at the high temperature and the change in internal energy, which is a combination of well-known effects of nonideal gases and changes in the chemical potential due to dissociation reactions. The major consideration to the non-work contribution to heat absorption comes from the enthalpy of reaction, for component m, as a result of the dissociation occurring during gas expansion, which can be calculated based on the information given previously. The unrecoverable, specific (per basis mole at low temperature, low pressure limit) contribution to the heat absorption (Q L ), from the high temperature thermal reservoir, owing to the enthalpy of reaction, is given by Equation 20. In this equation (Equation 20), ξ m,0 represents the extent of reaction before expansion, ξ m,f represents the extent of reaction after expansion, and ν m,i represents the stoichiometric coefficient, in each case for reaction m.
[0000] Q L =Σ m ((ξ m,f −ξ m,0 )(Σ i ν m,i ΔH f,i 0 )) E20.
[0076] In a manner similar to Equation 20, the heat absorbed during isochoric heating is given approximately by Equation 21, which includes the contribution of the specific heats of each component. There is some dependence of the internal energy on volume (other than the effect on reactions), but this effect is small for dinitrogen tetroxide and its derivative species. The constant volume specific heats were calculated by the author of the present disclosures using the Shomate equation and theoretical heat capacity ratios with a standard method based on the linearity or nonlinearity of the molecules of each species, and the number of bonds in the same molecule. This equation uses some notation from the background.
[0000] Q V ={Σ i ∫ T C T H n i c i,v dT+Σ m {(ξ m,f −ξ m,0 )(Σ i ν m,i ΔH f,i 0 )}} E20.
[0077] From the above listed equations, it is possible to derive an equation for the engine efficiency (Equation 21), where W S,j is the work for the Jth (Jε{1,2}) temperature at which expansion or compression is performed, and ε R is a measure of the energy efficiency of heat regeneration, ranging from 0 for no energy recovery from the cooling fluid to 1 for complete regeneration of the quantity of energy required for heating the fluid.
[0000]
ɛ
th
=
∑
J
W
s
,
J
W
S
,
2
+
(
1
-
ɛ
R
)
Q
V
+
Q
L
.
E
21
[0078] All of the quantities expressed in Equation 21 are intensive variables and scale with initial molar quantity of fluid, although they do not directly scale with molar concentration of the working fluid, since this affects the chemical equilibrium of involved reactions.
[0079] The engine device of the present disclosures has a theoretical efficiency limit that depends not only on temperature, but on the extent of one or more chemical reaction(s). Therefore, it may be advisable under particular circumstances to change the temperature limits of device operation from the temperature limits of the available heat sources and sinks so as to increase efficiency.
[0080] The method of the present disclosures provides a means for change the temperature limits of operation for the disclosed device, to increase efficiency, by the use of materials or additional devices, wherein said materials or devices are used to control heat flow from the high temperature thermal reservoir of the engine and/or to the low temperature thermal reservoir of the engine. Such materials or devices serve to control the rate of heat flow to or from the engine, to prevent the establishment of thermal equilibrium by the temperature reservoirs of the engine.
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Heat engines perform a thermodynamic cycle, making use of working fluid which increases pressure and/or volume in response to temperature, resulting in the transformation of heat into useful work. The present invention makes use of a particular type of working fluid that undergoes one or more reversible chemical reactions in response to an increase in temperature, to increase the molar quantity of fluid, producing more useful work and higher thermal efficiency than similar, conventional engines. One embodiment takes the form of a Stirling engine, with a regenerative heat exchange process which recovers most of the energy required to cause the chemical dissociation, ensuring efficiency gain. A method for selecting the working fluid, useful temperature ranges for the engine, and other operating parameters is also claimed. Other types of embodiments may take the form of turbine engines, with one embodiment being a turbine engine that approximates an Ericsson cycle.
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FIELD OF THE INVENTION
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/021,319 AND 61/021,316 both filed on Jun. 2, 2008 and both of which are incorporated herein in their entirety by reference.
[0002] The disclosed device relates to the setting of concrete anchors. More particularly the disclosed device and method of employment thereof relate to a tool for insertion of concrete anchors which is adapted for operative engagement to a hammer drill to thereby considerably increase the efficiency of workers setting such anchors in concrete and masonry structures.
BACKGROUND OF THE INVENTION
[0003] When mounting structural elements to concrete walls such as in tilt-up concrete structures, it is frequently necessary to provide a means for engagement of a threaded bolt with the concrete wall. The bolt being employed to hold some structural or decorative element must be screwed into the surface of the wall to provide the mounting engagement for the structural element.
[0004] In a conventional insertion of a wall anchor into a concrete wall, a hole is drilled into the surface of the wall to a distance sufficiently deep to provide for insertion of an internally threaded anchor, into the wall. In a second step, the wall anchor is inserted into the leading edge of the hole where it must be sunk into the hole prior to a third anchoring step.
[0005] Such inserts conventionally have an anchor circumference which is very close in size to the interior circumference of the hole in which it engages. Such tight engagements are required by the engineered structure of the insert and the need for the anchor to sufficiently grip the interior of the hole to support the load engaged on the bolt later threaded into the anchor.
[0006] As such, insertion of the anchor into the hole requires that it be forced by impact to a full engagement into the prior drilled hole. This can be a most tedious process since the holes are drilled into hard concrete and their can be dozens if not hundreds of such hole and anchor engagements on a supporting wall. The insertion of the anchors into the pre-drilled holes using a hammer can take an extremely large amount of worker time. Worse yet, the temperatures of the concrete can impact the time and effort required to insert the anchors since a hole drilled on a hot day, will contract on a subsequent cold day, making insertion of the anchor even more time consuming due to the conventional hammering method of insertion of each anchor.
[0007] Once inserted into the hole in a tight fit, each anchor must then be expanded by threading a bolt into the axially located threads of the anchor. The insertion of the bolt, deforms the anchor slightly such that it compresses in the circumferential engagement of the anchor and the sidewall of the hole. This compression fit is required to maintain the anchor in the hole under the anticipated load on the bolt.
[0008] However, just like hammering of the anchor into the hole is a tedious process, the insertion of the threaded bolt into the threaded axial cavity of the bolt is also a time-consuming process. As a consequence, the worker must first drill a hole in the wall. Then, the anchor must be driven into the hole by hand using a hammer. Finally, in a third step, the bolt must be rotated in the threaded engagement with the axial cavity using a wrench to twist it.
[0009] As such there is an unmet need for an improved apparatus and method for insertion of concrete anchors into their mounting holes which saves costly construction worker time. Such a device should allow for the use of the hammer drill that is employed to drill the holes in the wall, to insert the anchors into the hole using the power provided by the hammer drill rather than by the hand of the user on a hammer.
[0010] Further, such a device should also allow for employment of the hammer drill or other powered rotating tool, to rotate the bolt into the threaded axial cavity of the anchor thereby saving more time by eliminating the tedious employment of a conventional wrench to twist the bolt. Finally, such a device, should be easily engageable with conventional hammer drills, and should be a single unit which both allows for insertion of the anchor, and twisting of the bolt, without having to constantly remove the tool from the drill chuck.
[0011] In this respect, before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for designing other concrete anchor setting methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent construction insofar as they do not depart from the spirit and scope of the present invention.
[0012] An object of this invention is the provision of a device for engagement with concrete wall anchors and with a conventional hammer drill, to thereby provide a powered impact for driving the anchors into the pre-drilled holes.
[0013] An additional object of this invention is the provision of such an anchor driving device, which will also engage the bolt that must be threaded into the anchor, and provide a powered rotation thereof.
[0014] It is a further object of the invention herein, to provide such an anchor driving device and bolt rotating device, in a single unit to thereby eliminate the need to constantly remove and replace tools with the hammer drill chuck.
[0015] These together with other objects and advantages which will become subsequently apparent reside in the details of the construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout.
SUMMARY OF THE INVENTION
[0016] The device and method of operation herein described and disclosed substantially increases the speed of the tedious process of insertion of anchors and studs conventionally set into concrete and block walls and greatly reduces the number of tools, labor, and hence people required. Using a hammer drill in combination with the engageable two component device, a first component is adapted to engage in the jaws of a hammer drill on a proximal end and with a second component on the opposite end adapted for both the insertion of studs and the subsequent engagement of nuts upon the studs so inserted.
[0017] The distal end of the first component may be adapted with a threaded axial passage adapted to engage the threads of a concrete anchor for a hammering of the anchor without damaging the threads. Or it may be adapted which a passage for coaxial engagement of the stud while a socket adapted to engage a nut surrounding the passage engages the nut to both hammer the stud and rotate the nut onto the threads of the inserted stud.
[0018] The second component of the pair, engaged to the first component through a clutch, has a socket shaped and sized to engage the nuts of the anchor studs and to rotate them to a mount or bracket once the stud has been properly inserted and hammered into place. The second component may either be removably engageable to cooperatively engage with the clutch and surround the axial passage on the distal end of the shaft of the first component, or it may actually be a unitary structure and part of the clutch in its coaxial engagement surrounding the axial passage in the shaft.
[0019] Thus, in either the permanent mode or the removably engagement mode of the second component in a manner similar to a socket wrench, the combination of the two components allows for the employment of the hammer drill for both tasks without the need to change tools. In a first step the insert may be properly hammered into the aperture in the concrete by the engagement with either the threads of the stud insert or with a nut engaged upon the threads. Once hammered into proper position, the nut itself may be rotated by the socket type wrench formed in the distal end of the second component surrounding the axial cavity on the distal end of the shaft. Labor and time is greatly saved by employing the device instead of the conventional manner using hammers and wrenches in multiple steps.
[0020] These and further objectives of this invention will be brought out in the following part of the specification, wherein detailed description is provided for the purpose of fully disclosing the invention without placing limitations thereon.
[0021] With respect to the description provided herein, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the descriptions provided herein are considered as illustrative only of the principles of the invention.
[0022] Further, since numerous modifications and changes will readily occur to those skilled in the art, upon reading this disclosure, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents which may be resorted to, are considered to be within the scope of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 depicts the device herein having a removably engageable wrench component adapted for coaxial engagement over the central shaft to a mount on the clutch.
[0024] FIG. 2 depicts the central shaft of the device of FIGS. 1-3 adapted at a proximal end for engagement to a hammer drill and at the distal end for engagement with a threaded cement insert.
[0025] FIG. 3 is a perspective view of the device of FIG. 1 showing the second component cooperatively engaged with the clutch and surrounding the distal end of the shaft.
[0026] FIG. 4 is an end view of the device in the engaged configuration of FIG. 3 .
[0027] FIG. 5 shows and exploded view another mode of the device wherein the second component is permanently engaged on a first end to the clutch.
[0028] FIG. 6 depicts a perspective view of the device shown in FIG. 5 and assembled for use to both drive threaded wall anchors or studs, and rotatably engaged nuts thereon.
[0029] FIG. 7 is an end view of the device in FIG. 6 .
[0030] FIG. 8 depicts the prior art showing the conventional labor intensive manor currently employed to sink anchors or studs and subsequently engaged nuts thereon.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Referring now to the drawings in FIGS. 1-8 , wherein similar parts are identified by like reference numerals, as noted in FIG. 8 , it shows the conventional manner of engagement of concrete wall anchors into a pre-drilled hole. As shown, in the conventional method, a hole 12 is drilled into the concrete 14 to a predetermined depth using a hammer drill. The hole 12 is sized to be adapted for engagement to the insert or anchor 16 . Once the hole 12 is properly drilled to the correct depth and diameter, the anchor 16 is inserted into the hole 12 and its protruding threaded portion is communicated through an aperture in the supported structure 20 .
[0032] At this point in the process, the anchor 16 is in a tight fit with the sidewall of the hole 12 and will not just slide into engagement. Consequently, brute force in the form of a hammer 22 driven by the worker's hand, is employed to drive the anchor 16 to its mounting depth in the hole 12 .
[0033] In a third step of the conventional process, a nut 24 is engaged on the threaded end of the anchor 16 . The anchor 16 is designed in a conventional fashion for such anchors in that the engagement end which anchors in the hole 12 will expand when pulled upon by the rotating nut 24 . Different engagement ends exist for such purposes but all use the same basic premise of rotating the nut 24 , or the bolt 26 , with a wrench 28 , which will cause an outward expansion of the anchoring end of the bolt 26 , or of an insert engaging the anchoring end of the bolt 26 . This permanently seats the bolt 26 into the concrete.
[0034] As can be seen, this process is tedious and requires a constant changing of hand power tools to first drive the anchor 16 into the tight engagement with the hole 12 , and then expand the engagement end of the anchor 16 using rotation of the nut 24 or the bolt 26 with a second tool in the form of a wrench 28 .
[0035] The device 10 as shown in FIGS. 1-7 may be formed as a single unit or in a structure where the second component 32 which acts as a wrench, is removably engageable to a clutch 40 . In all modes of the device a shaft 29 is adapted at a first or proximal end 30 adapted to engage in the jaws or chuck of a conventional hammer drill. Such hammer drills are well known in the art and have both a hammering translating movement and also a rotational movement in the mode of a regular drill.
[0036] The second component 32 is adapted to coaxially engage around the shaft 29 on the distal or opposite end from the proximal end 30 of the shaft. In the removable mode of the device 10 of FIGS. 1-3 , a first end 34 of the second component 32 is shaped to cooperatively engage a cooperating cavity 36 on the clutch 40 . The distal end 33 of the second component 32 shown in FIGS. 1 and 4 , is adapted to engage the nuts 24 of the conventionally employed anchors noted above.
[0037] The distal end 31 of the shaft 29 as shown in FIGS. 1 , 2 , and 5 , may have a threaded cavity 38 which is adapted to engage the threaded portion of the anchor 16 during insertion noted above. Optionally, the cavity 38 may be sized to surround the threads on the studs or anchors if preferred and the nut engaging cavity 39 employed to engage upon the anchor-engaged nut 24 to drive the anchor 16 into the hole 12 .
[0038] A clutch 40 may be provided, and is preferred in all modes of the device 10 . While the device 10 may be employed without the clutch 40 and still improve upon the state of the art by providing one tool to provide a mechanized solution to the current act of multiple tools and steps, the clutch 40 is particularly preferred. This is because it provides a means to prevent over-torque of the nut 24 on the projecting threaded portion of the anchor. This is most important as over-torque of the nut 24 will snap the anchor 16 in half. If the anchor 16 is mounted into the concrete by the force imparted, and the anchor 16 breaks off, it is extremely hard to remove from the concrete, and can take many hours if indeed it can be removed. The clutch 40 thereby provides a means to prevent excessive force from being imparted to the nut 24 and the anchor 16 to prevent this occurrence.
[0039] The clutch 40 as shown in FIG. 5 in one preferred mode of a clutch 40 employs a collar 51 which is threaded upon the center portion 53 of the shaft 29 which has been coaxially engaged through the front clutch plate 55 . A shoulder 56 on the shaft 29 is sized to contact a ridge 57 on the axial aperture 58 of the front clutch plate 55 . The collar 51 is then rotated on the threads of the shaft 29 to a point where springs 59 bias the balls 60 into the detents 62 of the front clutch plate 55 . The clutch 40 may be adjusted to slip under more or less torque from the shaft 29 by moving the collar 55 closer or further from the front clutch plate 55 . Thus the clutch 40 is adjustable for a maximum amount of torque before the force from the shaft 29 will cause slippage and prevent the second component 32 from rotating with a force that exceeds the maximum torque allowed to prevent breakage of the anchor 16 or similar insert. Of course those skilled in the art will realize other clutch designs may be employed and such are anticipated in the scope of this application. However, because the device 10 is employed to impart a hammer force from the hammer drill, the current design provides a one piece continuous shaft 29 , to impart that hammering force directly to the anchor 16 and in no manner effect the workings of the clutch 40 . Any other clutch design should take this into consideration to avoid having the hard hammering forces imparted to clutch parts as it would cause wear problems over time.
[0040] The device 10 , in use engaged to a conventional hammer drill will as noted above remarkably decrease the time and effort involved in setting anchors 16 and the like, and attaching the nuts 24 to hold whatever is being mounted. In such use, the threaded portion of the insert or anchor 16 would be engaged with the threaded cavity 38 on the distal end of the shaft 29 with the proximal end 37 engaged to a hammer drill. Using the hammer function of the drill, the anchor 16 is forced in a pre-drilled hole. Alternatively, as noted, if the cavity 38 is not threaded but simply of a larger diameter than the anchor 16 , a nut 24 is engaged upon the anchor 16 and the nut-engaging cavity 39 will contact the nut 24 in its engagement to the anchor 16 and the drill may hammer the anchor into the concrete.
[0041] In the second step, either the threaded cavity 38 if present or the nut engaging cavity 39 are disengaged from the anchor 16 . The bracket 20 ( FIG. 8 ) is slid upon the threaded portion of the anchor 16 , and the nut 24 can then be re-engaged on the threads of the anchor 16 and with the nut-engaging cavity 39 whereafter using the rotation mode of the hammer drill or another drill, the nut 24 is rotated engaged to threads of the insert or anchor 16 and tightened against the bracket 49 or other item being mounted. In this step, it is preferred that the clutch 40 is present and set to slip before the hammer drill exerts excessive force to the anchor 16 which could break it off.
[0042] As such, the process of setting the anchors 16 or similarly hole-engaged mounting components is significantly enhanced by the employment of the hammer drill on hammer-action with the first component 30 , to set the anchors 16 , and the employment of the easily engaged cavity 39 of the second component 32 with the subsequent use of the rotation motion of the drill to install the nuts 24 .
[0043] The method and components shown in the drawings and described in detail herein disclose arrangements of elements of particular construction, and configuration for illustrating preferred embodiments of structure of the presently disclosed concrete anchor insertion system in cooperation with a hammer drill having two modes of operation. It is to be understood, however, that elements of different construction and configuration, and using different steps and process procedures, and other arrangements thereof, other than those illustrated and described, may be employed in accordance with the spirit of this invention.
[0044] As such, while the present invention has been described herein with reference to particular embodiments thereof, a latitude of modifications, various changes and substitutions are intended in the foregoing disclosure, and will be appreciated that in some instance some features of the invention could be employed without a corresponding use of other features, without departing from the scope of the invention as set forth in the following claims. All such changes, alternations and modifications as would occur to those skilled in the art are considered to be within the scope of this invention as broadly defined in the appended claims.
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A device for mounting anchors having a mounting end for positioning within pre-drilled apertures formed in concrete or cement and having a threaded end projecting forward of the pre-drilled apertures when positioned therein. The device features a continues shaft that is adapted to engage with a hammer drill on a first end, and the threaded portion of the anchor on the opposite end to allow the hammer drill to force the anchor into its aperture in the concrete. A nut for the threaded portion is rotatable for engagement by a second component coaxially engaged with the shaft. The device allows for both hammering the anchor into its aperture and tightening the nut, without removing the device from its engagement with the anchor.
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BACKGROUND OF THE INVENTION
The invention relates to thermoplastic polycarbonate compositions which are impact-modified with ABS type polymers.
The inventive polycarbonate (PC) compositions which are impact-modified with ABS type polymers are characterized by their excellent low temperature ductility, good processing properties expressed by relatively high melt volume rate (MVR) and good hydrolytic stability. Impact-modified polycarbonate compositions., e.g. those blends with ABS (acrylonitrile-butadiene-styrene polymer), are known for their high ductility at room temperature and low temperatures and good processing properties. However, for realization of demanding uses, in particular complex component geometries, it is often desirable to improve the processing properties further. Conventional measures lead to the desired improvement, however, as a rule cause a deterioration in the toughness. This is critical in view of fact that as high quality requirements of ductility, in some cases down to low temperatures, are as a rule imposed on components of PC/ABS, e.g. safety parts in automobile construction.
From EP 0 704 488 B1 PC/ABS moulding compositions are known with graft polymers which are based on a rubber polymer latex which has a weight median average particle diameter D 50 from 0.20 to 0.35 μm. For using rubber polymer latices outside this range it is reported that especially the low temperature impact is significantly reduced.
From WO 01/62812 A1 the following composition is known. The composition contains two graft polymers and one thermoplastic polymer which can be described shortly as:
first graft of styrene and acrylonitrile monomers onto a first rubber latex with a D 50 diameter of 80 to 228 nm whereby this rubber latex is provided by seed feed emulsion polymerization using a seed with diameter of 10 to 100 nm second craft of styrene and acrylonitrile monomers onto a second rubber latex with a D 50 diameter of 340 to 480 nm whereby this rubber is provided by seed feed emulsion polymerization using as seed the first rubber latex rubber-free copolymer from styrene and acrylonitrile.
It is reported that the grafts can be polymerized separately or can be produced in a common grafting of a mixture of the two rubber latices but from the examples only grafts are known which are polymerized separately. WO 01/62812 A1 mentions a number of thermoplastics resin, that can be used in addition to the styrene-acrylonitrile copolymer, including polycarbonate. However there are no specific examples of PC/ABS blends and thus it is also not taught in this document whether this composition would have beneficial results in PC/ABS blends. Moreover none of the examples has the parameters of the butadiene latices as used in the present invention.
Similarly from WO 01/62850 A1 compositions are known which are taught also to be suitable for PC/ABS compositions, The compositions contain a graft polymer onto a mixture of three rubber latices and a thermoplastic polymer which can be described shortly as:
graft polymer of styrene and acrylonitrile monomer onto a mixture of three rubber latices
first rubber latex with a D 50 diameter of ≦250 nm and a gel content of 30 to 95% second rubber latex with a D 50 diameter of >250 nm to 350 nm and a gel content of 30 to 80% third rubber latex with a D 50 diameter of >350 nm and a gel content of 50 to 95% whereby at least one of the rubber latices is produced by seed feed emulsion polymerization
rubber-free copolymer from styrene and acrylonitrile.
It is not taught that this composition would have beneficial results in PC/ABS blends. Again there are no specific examples of a PC/ABS composition nor do any of the examples meet the features of present invention.
Similarly from WO 01/62848 A1 compositions are known which are claimed also to be suitable for PC/ABS compositions. The compositions contain at least two graft polymers onto rubber latices and one thermoplastic polymer which can be described shortly as:
a first graft polymer of styrene and acrylonitrile monomers onto a first rubber latex with a D 50 diameter of 230 to 330 nm whereby the third rubber latex is used as seed in the emulsion polymerization of the first rubber latex, a second graft polymer of styrene and acrylonitrile monomers onto a second rubber latex with a D 50 diameter of 340 to 480 nm whereby the third rubber latex is used as seed in the emulsion polymerization of the second rubber latex, and optionally a third graft polymer of styrene and acrylonitrile monomers onto a third rubber latex with a D 50 diameter of 10 to 220 nm, rubber-free copolymer from styrene and acrylonitrile,
It is reported that the grafts can be polymerized separately or can be produced in a common grafting of a mixture of the two or three rubber latices but from the trials only grafts are known in which the first and second rubber latices are mixed and then grafted together and the third rubber latex with a D 50 diameter is grafted separately. WO 01/62848 A1 mentions a number of thermoplastics resin, that can be used in addition to the styrene-acrylonitrile copolymer, including polycarbonate. However, there are no specific examples of PC/ABS blends and thus it is also not taught in this document whether this composition would have beneficial results in PC/ABS blends. Moreover none of the examples has the parameters of the butadiene latices as used in the present invention.
From WO 01/66840 A1 PC/ABS compounds are known comprising the following components:
polycarbonate with styrene and acrylonitrile grafted rubber based on at least two rubber latices whereas
the first rubber latex has a diameter D 50 ≦350 nm, preferably 260 to 310 nm, specifically 277 nm, and an gel content ≦70 wt.-% and the second rubber latex has a diameter D 50 ≧350 nm and an gel content ≧70 wt.-%
rubber-free copolymer from styrene and acrylonitrile.
Examples show that there is an improvement in properties like impact strength and elongation at break when a mixture of the above named rubbers are used compared to only one rubber latex with a diameter D 50 <350 nm. However, no data are submitted as to low temperature impact strength, and it seems also that there is still a lack in low temperature ductility. Accordingly low temperature properties still need to be improved, in particular, the balance of the properties like impact strength and ductility at low temperature is still to be improved.
From DE 196 39 821 A1 PC/ABS compounds are known which comprises the following components:
polycarbonate
with styrene and acrylonitrile grafted rubber based on at least one ore more rubber latices whereas at the most 70 wt.-% of the rubber particles have a diameter larger than 180 nm.
rubber-free copolymer from styrene and acrylonitrile or polyalkylene terephthalate.
Examples show some improvements are visible with the filling pressure but it seems that there is still a lack in low temperature ductility.
Therefore, there is still room for improving the mechanical properties of PC/ABS compositions especially low temperature ductility, a good MVR and a good hydrolytic stability.
SUMMARY OF THE INVENTION
Surprisingly it was found that special graft rubber polymers based on a mixture of at least two rubber latices with a special particle size and special gel content in a specific ratio result in the desired improved PC/ABB properties.
Accordingly the present invention provides a resin composition comprising:
A) 5 to 99 wt.-parts of at least one aromatic polycarbonate, B) 1 to 95 wt.-parts of at least one graft rubber copolymer which is obtained by:
emulsion polymerization of styrene and acrylonitrile in the weight ratio 95:5 to 50:50, whereby styrene and/or acrylonitrile wholly or partially can be replaced by copolymerizable monomers, onto at least two rubber latices, comprising: a butadiene rubber latex (B1) having a weight median particle diameter D 50 of 100 to 250 nm, and a gel content from 30 to 80% by weight (wt), and a butadiene rubber latex (B2) having a weight median particle diameter D 50 of more than 350 nm, and a gel content of less than 75% by weight,
C) optionally 0 to 50 wt.-parts of one or more (co)polymer of at least one monomer selected from the group consisting of vinyl aromatic monomers, vinyl cyanides and unsaturated carboxylic acids and derivatives thereof, D) optionally 0 to 25 wt.-parts of conventional polymer additives,
wherein the weight median particle diameter D 50 of the mixture of the butadiene rubber latices (B1) and (B2) is larger than 350 nm and is less than 1000 nm, and the amount of the butadiene rubber latex polymer (B1) in the graft rubber copolymer B) is 1 to 49% by weight (B1) and the amount of the butadiene rubber latex polymer (B2) is 51 to 99% by weight, based on the total weight of the rubber latex polymers in the graft rubber copolymer B).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The resin composition according to the present invention preferably comprises:
A) 5 to 95 wt.-parts, preferably 10 to 90 wt.-parts, most preferably 20 to 80 wt.-parts aromatic polycarbonate, B) 1 to 50 wt.-parts, preferably 2 to 40 wt.-parts, most preferably 3 to 30 wt.-parts of at least one grafted rubber, which is obtained by emulsion polymerization of styrene and acrylonitrile in the weight ratios 95:5 to 50:50 whereby styrene and/or acrylonitrile wholly or partially can be replaced by copolymerizable monomers, preferably by alpha-methylstyrene, methyl methacrylate, maleic anhydride or N-phenylmaleimide onto at least two rubber latices whereas the butadiene rubber latex (B1) has a weight median particle diameter D 50 of 100 to 250 nm, preferably 100 to 220 nm and particular preferably 150 to less than 200 nm and a gel content from 30 to 80% by wt., preferably 40 to 75% by wt., particular preferably 45 to 75% by wt. preferably 60 to 80% by wt. more preferably 60 to 75% by wt., and the butadiene rubber latex (B2) has a weight median particle diameter D 50 of more than 350 nm, preferably 350 to 1000 nm, preferably 350 to 800 nm and particular preferably 360 to 500 nm and a gel content of less than 75% by wt., preferably less than 70% by wt., preferably 40 to less than 70% by wt., particular preferably 45 to less than 70% by wt. C) 0 to 50 wt.-parts of a (co)polymers of at least one monomer from the group consisting of vinyl aromatic monomers, vinyl cyanides (unsaturated nitrites), unsaturated carboxylic acids and derivatives thereof, such as (meth)acrylic acid (C 1 to C 8 )-alkyl esters, unsaturated carboxylic acids, e.g. anhydrides and imides of unsaturated carboxylic acids, D) 0.5 to 25 wt.-parts of conventional polymer additives, preferably 0.5 to 5 wt.-parts, most preferably 0.5 to less than 1 wt.-parts,
In a preferred embodiment the indication wt.-parts (weight parts) represent wt.-%, based on the total weight of the resin composition, i.e. in a preferred embodiment the resin composition comprises:
A) 5 to 99 wt.-% of at least one aromatic polycarbonate, B) 1 to 95 wt.-% of at least one graft rubber copolymer, as defined before: emulsion polymerization of styrene and acrylonitrile in the weight ratio 95:5 to 50:50, whereby styrene C) optionally 0 to 50 wt.-% of one or more (co)polymer as defined before, and D) optionally 0 to 25 wt.-% of conventional polymer additives, the weight-percentages being based on the total weight of the resin composition.
In a preferred embodiment the resin composition of the invention comprises:
A) 30 to 80 wt.-% of at least one aromatic polycarbonate, B) 5 to 30 wt.-% of at least one graft rubber copolymer, and C) 10 to 40 wt.-% of one or more (co)polymer, and optionally 0 to 25 wt.-% of conventional polymer additives D), each as defined before and the weight-percentages being based on the total weight of the resin composition.
In a preferred embodiment the resin composition consists only of the components A) to D).
The weight median particle diameter D 50 of the mixture of the butadiene rubber latices (B1) and (B2) is larger than 350 nm, preferably larger than 355 nm and particularly preferably larger than 360 nm and the weight median particle diameter D 50 , of the mixture of the butadiene rubber latices (B1) and (B2) is less than 1000 nm, preferably less than 800 nm, most preferably less than 500 nm and the amount of the butadiene rubber latex polymer (B1) in the graft polymer B is 1 to 49% by wt. (B1) and the amount of the butadiene rubber latex polymer (B2) is 51 to 99% by wt., and the amount of the butadiene rubber latex polymer (B1) in the graft polymer B is preferably 10 to 40% by wt, (B1) and the amount of the butadiene rubber latex polymer (52) is preferably 60 to 90% by wt. and the amount of the butadiene rubber latex polymer (B1) in the graft polymer B is particularly preferably 15 to 35% by wt. (B1) and the amount of the butadiene rubber latex polymer (52) is particularly preferably 65 to 85% by wt based on the total weight of the rubber latex polymers in the graft rubber copolymer B).
Component A) (Aromatic Polycarbonate)
Component A) includes one or more, preferably one or two, more preferably one aromatic polycarbonate.
Component A) includes for example polycondensation products, for example aromatic polycarbonates, aromatic polyester carbonates.
Aromatic polycarbonates and/or aromatic polyester carbonates according to component A) which are suitable according to the invention are known from the literature or may be prepared by processes known from the literature (for the preparation of aromatic polycarbonates see, for example, Schnell, “Chemistry and Physics of Polycarbonates”, Interscience Publishers, 1964 and DE-AS 1 495 626, DE-A 2 232 877, DE-A 2 703 376, DE-A 2 714 544, DE-A 3 000 610 and DE-A 3 832 396; for the preparation of aromatic polyester carbonates e.g. DE-A 3 077 934). The preparation of aromatic polycarbonates is carried out e.g. by reaction of diphenols with carbonic acid halides, preferably phosgene, and/or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, by the phase interface process, optionally using chain terminators, for example monophenols, and optionally using branching agents which are trifunctional or more than trifunctional, for example triphenols or tetraphenols. A preparation via a melt polymerization process by reaction of diphenols with, for example, diphenyl carbonate is also possible.
Diphenols for the preparation of the aromatic polycarbonates and/or aromatic polyester carbonates are preferably those of the formula (I)
wherein
A is a single bond, C 1 to C 5 -alkylene, C 2 to C 5 -alkylidene, C 5 to C 6 -cycloalkylidene, —O—, —SO—, —CO—, —S—, —SO 2 —, C 6 to C 12 -arylene, on to which further aromatic rings optionally containing heteroatoms may be fused,
or a radical of the formula (II) or (III),
B in each case is C 1 to C 12 -alkyl, preferably methyl, or halogen, preferably chlorine and/or bromine, x in each case independently of one another, is 0, 1 or 2,
p is 1 or 0 and
R 5 and R 6 individually for each X 1 and independently of one another denote hydrogen or C 1 to C 6 -alkyl, preferably hydrogen, methyl or ethyl,
X 1 denotes carbon and
m denotes an integer from 4 to 7, preferably 4 or 5, with the proviso that on at least one atom X 1 , R 5 and R 6 are simultaneously alkyl.
Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis-(hydroxyphenyl)-C 1 -C 5 -alkanes, bis-(hydroxyphenyl)-C 5 -C 6 -cycloalkanes, bis-(hydroxyphenyl)ethers, bis-(hydroxyphenyl)sulfoxides, bis-(hydroxyphenyl)ketones, bis-(hydroxyphenyl)sulfones and α,α-bis-(hydroxyphenyl)-dilsopropyl-benzenes and nucleus-brominated and/or nucleus-chlorinated derivatives thereof. Particularly preferred diphenols are 4,4′-dihydroxydiphenyl, bisphenol A, 2,4-bis-(4-hydroxyphenyl)-2-methylbutane, 1,1-bis-(4-hydroxyphenyl)-cyclohexane, 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl sulfone and di- and tetrabrominated or chlorinated derivatives thereof, such as, for example, 2,2-bis-(3-chloro-4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane ear 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane. 2,2-bis-(4-hydroxyphenyl)-propane (bisphenol A) is particularly preferred. The diphenols may be employed individually or as any desired mixtures. The diphenols are known from the literature or obtainable by processes known from the literature.
Chain terminators which are suitable for the preparation of the thermoplastic, aromatic polycarbonates are, for example, phenol, p-chlorophenol, p-tert-butylphenol or 2,4,6-tribromophenol, and also long-chain alkylphenols, such as 4-[2-(2,4,4-trimethylpentyl)]-phenol, 4-(1,3-tetramethylbutyl)-phenol according to DE-A 2 842 005 or monoalkylphenols or dialkylphenols having a total of 8 to 20 carbon atoms in the alkyl substituents, such as 3,5-di-tert-butylphenol, p-iso-octylphenol, p-tert-octylphenol, p-dodecylphenol and 2-(3,5-dimethylheptyl)-phenol and 4-(3,5-dimethylheptyl)-phenol. The amount of chain terminators to be employed is in general between 0.5 mol % and 10 mol %, based on the sum of the moles of the particular diphenols employed.
The thermoplastic, aromatic polycarbonates have average weight-average molecular weights (M w , measured e.g. by ultracentrifuge or scattered light measurement) of from 10,000 to 200,000 g/mol, preferably 15,000 to 80,000 g/mol, particularly preferably 24,000 to 32,000 g/mol. The thermoplastic, aromatic polycarbonates may be branched in a known manner, and in particular preferably by incorporation of from 0.05 to 2.0 mol %, based on the sum of the diphenols employed, of compounds which are trifunctional or more than trifunctional, for example those having three and more phenolic groups. Both homopolycarbonates and copolycarbonates are suitable. It is also possible for 1 to 25 wt. %, preferably 2.5 to 25 wt. %, based on the total amount of diphenols to be employed, of polydiorganosiloxanes having hydroxyaryloxy end groups to be employed for the preparation of copolycarbonates according to the invention according to component A. These are known (U.S. Pat. No. 3,419,634) and may be prepared by processes known from the literature. The preparation of copolycarbonates containing polydiorganosiloxanes is described in DE-A 3 334 782. Preferred polycarbonates are, in addition to the bisphenol A homopolycarbonates, the copolycarbonates of bisphenol A with up to 15 mol %, based on the sum of the moles of diphenols, of other diphenols mentioned as preferred or particularly preferred, in particular 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane.
Aromatic dicarboxylic acid dihalides for the preparation of aromatic polyester carbonates are preferably the diacid dichlorides of isophthalic acid, terephthalic acid, diphenyl ether-4,4′-dicarboxylic acid and of naphthalene-2,6-dicarboxylic acid. Mixtures of the diacid dichlorides of isophthalic acid and of terephthalic acid in a ratio of between 1:20 and 20:1 are particularly preferred. A carbonic acid halide, preferably phosgene, is additionally co-used as a bifunctional acid derivative in the preparation of polyester carbonates. Possible chain terminators for the preparation of the aromatic polyester carbonates are, in addition to the monophenols already mentioned, also chlorocarbonic acid esters thereof as well as the acid chlorides of aromatic monocarboxylic acids, which may optionally be substituted by C 1 to C 22 alkyl groups or by halogen atoms, as well as aliphatic C 2 to C 22 -monocarboxylic acid chlorides. The amount of chain terminators is in each case 0.1 to 10 mol %, based on the moles of diphenol in the case of the phenolic chain terminators and on the moles of dicarboxylic acid dichloride in the case of monocarboxylic acid chloride chain terminators. The aromatic polyester carbonates may also contain incorporated aromatic hydroxycarboxylic acids.
The aromatic polyester carbonates may be either linear or branched in a known manner (in this context see DE-A 2 940 024 and DE-A 3 007 934). Branching agents which may be used are, for example, carboxylic acid chlorides which are trifunctional or more than trifunctional, such as trimesic acid trichloride, cyanuric acid trichloride, 3,3′,4,4′-benzophenone-tetracarboxylic acid tetrachloride, 1,4,5,8-naphthalenetetracarboxylic acid tetrachloride or pyromellitic acid tetrachloride, in amounts of from 0.01 to 1.0 mol % (based on the dicarboxylic acid dichlorides employed), or phenols which are trifunctional or more than trifunctional, such as phloroglucinol, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-hept-2-ene, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)-ethane, tri-(4-hydroxyphenyl)-phenylmethane, 2,2-bis-[4,4-bis-(4-hydroxyphenyl)-cyclohexyl]-propane, 2,4-bis-(4-hydroxyphenyl-isopropyl)-phenol, tetra-(4-hydroxyphenyl)-methane, 2,6-bis-(2-hydroxy-5-methyl-benzyl)-4-methyl-phenol, 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane, tetra-(4-[4-hydroxyphenyl-isopropyl]-phenoxy)-methane and 1,4-bis-[4,4′-dihydroxytriphenyl)-methyl]-benzene, in amounts of from 0.01 to 1.0 mol %, based on the diphenols employed. Phenolic branching agents may be initially introduced into the reaction vessel with the diphenols, and acid chloride branching agents may be introduced together with the acid dichlorldes.
The content of carbonate structural units in the thermoplastic, aromatic polyester carbonates may be varied as desired. Preferably, the content of carbonate groups is up to 100 mol %, in particular up to 80 mol %, particularly preferably up to 50 mol %, based on the sum of ester groups and carbonate groups. Both the ester and the carbonate content of the aromatic polyester carbonates may be present in the polycondensate in the form of blocks or in random distribution.
The relative solution viscosity (η rel ) of the aromatic polycarbonates and polyester carbonates is in the range of 1.18 to 1.4, preferably 1.20 to 1.32 (measured on solutions of 0.5 g polycarbonate or polyester carbonate in 100 ml methylene chloride solution at 25° C.). The thermoplastic, aromatic polycarbonates and polyester carbonates may be employed by themselves or in any desired mixture of one or more, preferably one to three or one or two thereof. Most preferably only one type of polycarbonate is used.
Most preferably the aromatic polycarbonate is a polycarbonate based on bisphenol A and phosgene, which includes polycarbonates that have been prepared from corresponding precursors or synthetic building blocks of bisphenol A and phosgene. These preferred aromatic polycarbonates may be linear or branched due to the presence of branching sites.
It is possible according to the present invention that the resin composition may include other thermoplastic resins like polyesters or polyamides in particular in an amount of up to 20 weight-% of the total weight of the resin composition.
Suitable thermoplastic polyesters are preferably polyalkylene terephthalates, that is to say reaction products of aromatic dicarboxylic acids or reactive derivatives thereof (e.g. dimethyl esters or anhydrides) and aliphatic, cycloaliphatic or arylaliphatic dials, and mixtures of such reaction products. Preferred polyalkylene terephthalates may be prepared from terephthalic acids (or reactive derivatives thereof) and aliphatic or cycloaliphatic diols having from 2 to 10 carbon atoms according to known methods (Kunststoff-Handbuch, Volume VIII, p. 695 ff, Carl Hanser Verlag, Munich 1973).
In preferred polyalkylene terephthalates, from 80 to 100 mol %, preferably from 90 to 100 mol %, of the dicarboxylic acid radicals are terephthalic acid radicals, and from 80 to 100 mol %, preferably from 90 to 100 mol %, of the diol radicals are ethylene glycol and/or 1,4-butanediol radicals. The preferred polyalkylene terephthalates may contain, in addition to ethylene glycol or 1,4-butanediol radicals, from 0 to 20 mol % of radicals of other aliphatic diols having from 3 to 12 carbon atoms or cycloaliphatic diols having from 6 to 12 carbon atoms, for example radicals of 1,3-propanediol, 2-ethyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 3-methyl-1,3- and -1,6-pentanediol, 2-ethyl-1,3-hexanediol, 2,2-diethyl-1,3-propanediol, 2,5-hexanediol, 1,4-di(β-hydroxyethoxy)benzene, 2,2(bis-4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane, 2,2-bis-(3-β-hydroxyethoxyphenyl)-propane and 2,2-bis-(4-hydroxypropoxyphenyl)-propane (DE-A 2 407 647, 2 407 776, 2 715 932).
The polyalkylene terephthalates may be branched by incorporation of relatively small amounts of tri- or tetra-hydric alcohols or tri- or tetra-basic carboxylic acids, such as are described in DE-A 1 900 270 and U.S. Pat. No. 3,692,744. Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylol-ethane and -propane and pentaerythritol. It is advisable to use not more than 1 mol % of the branching agent, based on the acid component. Particular preference is given to polyalkylene terephthalates that have been prepared solely from terephthalic acid and reactive derivatives thereof (e.g. dialkyl esters thereof) and ethylene glycol and/or 1,4-butanediol, and mixtures of such polyalkylene terephthalates.
Preferred polyalkylene terephthalates are also copolyesters prepared from at least two of the above-mentioned alcohol components: particularly preferred copolyesters are poly-(ethylene glycol 1,4-butanediol) terephthalates,
The polyalkylene terephthalates that are preferably suitable generally have an intrinsic viscosity of from 0.4 to 1.5 dL/g, preferably from 0.5 to 1.3 dL/g, especially from 0.6 to 1.2 dL/g, in each case measured in phenol/o-dichlorobenzene (1:1 parts by weight) at 25° C.
Suitable polyamides are known homopolyamides, copolyamides and mixtures of such polyamides. They may be semi-crystalline and/or amorphous polyamides.
Suitable semi-crystalline polyamides are polyamide-6, polyamide-6,6, mixtures and corresponding copolymers of those components. Also included are semi-crystalline polyamides the acid component of which consists wholly or partially of terephthalic acid and/or isophthalic acid and/or suberic acid and/or sebacic acid and/or azelaic acid and/or adipic acid and/or cyclonexanedicarboxylic acid, the diamine component of which consists wholly or partially m- and/or p-xylylene-diamine and/or hexamethylenediamine and/or 2,2,4-trimethylhexamethylenediamine and/or 2,2,4-trimethylhexamethylenediamine and/or isophoronediamine, and the composition of which is in principle known. Mention may also be made of polyamides that are prepared wholly or partially from lactams having from 7 to 12 carbon atoms in the ring, optionally with the concomitant use of one or more of the above-mentioned starting components.
Particularly preferred semi-crystalline polyamides are polyamide-6 and polyamide-6,6 and mixtures thereof. Known products may be used as amorphous polyamides. They are obtained by polycondensation of diamines, such as ethylenediamine, hexamethylenediamine, decamethylenediamine, 2,2,4- and/or 2,4,4-trimethylhexamethylenediamine, m- and/or p-xylylene-diamine, bis-(4-aminocyclohexyl)-methane, bis-(4-aminocyclohexyl)-propane, 3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 2,5- and/or 2,6-bis-(aminomethyl)-norbornane and/or 1,4-diaminomethylcyclohexane, with dicarboxylic acids such as oxalic acid, adipic acid, azelaic acid, azelaic acid, decanedicarboxylic acid, heptadecanedicarboxylic acid, 2,2,4- and/or 2,4,4-trimethyladipic acid, isophthalic acid and terephthalic acid. Also suitable are copolymers obtained by polycondensation of a plurality of monomers, as well as copolymers prepared with the addition of aminocarboxylic acids such as ε-aminocaproic acid, ω-aminoundecanoic acid or ω-aminolauric acid or their lactams. Particularly suitable amorphous polyamides are the polyamides prepared from isophthalic acid, hexamethylenediamine and further diamines such as 4,4′-diaminodicyclohexylmethane, isophoronediamine, 2,2,4- and/or 2,4,4-trimethylhexamethylenediamine, 2,5- and/or 2,6-bis-(aminomethyl)-norbornene; or from isophthalic acid, 4,4′-diamino-dicyclohexylmethane and ε-caprolactam; or from isophthalic acid, 3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane and laurinlactam; or from terephthalic acid and the isomeric mixture of 2,2,4- and/or 2,4,4-trimethylhexamethylenediamine. Instead of pure 4,4′-diaminodicyclohexylmethane it is also possible to use mixtures of the position-isomeric diaminodicyclohexylmethanes, which are composed of from 70 to 99 mol % of the 4,4′-diamino isomer, from 1 to 30 mol % of the 2,4′-diamino isomer, from 0 to 2 mol % of the 2,2′-diamino isomer and optionally corresponding to more highly condensed diamines, which are obtained by hydrogenation of industrial grade diaminodiphenylmethane. Up to 30% of the isophthalic acid may be replaced by terephthalic acid.
The polyamides preferably have a relative viscosity (measured on a 1 wt. % solution in m-cresol or 1% (weight/volume) solution in 96 wt. % sulfuric acid at 25° C.) of from 2.0 to 5.0, particularly preferably from 2.5 to 4.0.
Component B) (Graft Rubber Copolymer)
Butadiene Rubber Latices (B1) and (B2)
The butadiene rubber latices (B1) and (B2) used to prepare the graft rubber copolymer component B) are preferably produced using the emulsion polymerization of butadiene monomer according to the so-called seed-feed technology whereby first a small sized rubber latex, preferably a butadiene rubber latex, is produced and subsequently the particle size is increased by polymerization and by increasing the monomer conversion of butadiene or monomer mixtures containing butadiene (see e.g. Houben-Weyl, Methoden der organischen Chemie, Makromolekulare Stoffe Teil 1, S. 339 (1961) Thieme Verlag Stuttgart). Preferably a seed-batch or a seed-feed process is used.
Up to 50% by wt. (based on the total amount of monomers used for the production of polybutadiene polymers) of one or more monomers that are copolymerizable with butadiene can be used as comonomers. Examples for such monomers include isoprene, chloroprene, acrylonitrile, styrene, alpha-methylstyrene, C 1 -C 4 -alkylstyrenes, C 1 -C 8 -alkylacrylates, C 1 -C 8 -alkylmethacrylates, alkyleneglycol diacrylates, alkylenglycol dimethacrylates, divinylbenzol; preferably, butadiene is used alone or mixed with up to 20% by wt., preferably 15% by wt. styrene and/or acrylonitrile. Preferred butadiene rubber latex polymers (B1) and (B2) are polybutadiene and butadiene-styrene copolymers.
As seed latex polymers preferrently butadiene polymers are used, e.g. polybutadiene, butadiene-styrene copolymers, butadiene-acrylonitrile polymers or polymers from the above mentioned monomers. In principal other small sized latices can be used, e.g. polystyrene or styrene copolymers, polymethylmethacrylate or methacrylate copolymers or polymerisates from other vinylic monomers. Preferred seed latex polymers are polybutadiene latices.
For the production of the butadiene rubber latices (B1) preferably a seed latex with a weight median particle diameter D 50 of 10 to 60 nm, preferably of 20 to 50 nm is used. For the production of the butadiene rubber latices (B2) preferably a seed latex with a weight median particle diameter D 50 of 10 to 220 nm, preferably 20 to 210 nm and most particularly preferably 30 to 200 nm is used.
The butadiene rubber latex (B1) has a weight median particle diameter D 50 of 100 to 250 nm, preferably 100 to 220 nm and particular preferably 150 to less than 200 nm. The gel content has values from 30 to 80% by preferably 40 to 75% by wt., particular preferably 45 to 75% by wt.
The butadiene rubber latex (B2) has a weight median particle diameter D of more than 350 nm, preferably more than 350 to 1000 nm, preferably 350 to 800 nm and particular preferably 360 to 500 nm. The gel content has values of less than 75% by weight, preferably less than 70% by wt., preferably 40 to less than 70% by wt., particular preferably 45 to less than 70% by wt.
The determination of the weight median particle diameter D 50 can be carded out by a measurement with an ultracentrifuge (see W. Scholtan, H. Lange; Kolloid Z. u. Z. Polymere 250, pp. 782 to 796(1972)) or a disc centrifuge DC 24000 by CPS Instruments Inc. at a rotational speed of the disc of 24,000 r.p.m. The weight median particle size D 50 is the diameter which divides the population exactly into two equal parts, 50% by wt. of the particles are larger than the median particle size D 50 and 50% by wt. are smaller. Also the weight average particle size D w can be calculated from these measurements. For the definition of D w see: G. Lagaly, O. Schulz, R. Ziemehl: Dispersionen und Emulsionen: eine Einführung in die Kolloidik feinverteilter Stoffe einschlieβlich der Tonminerale, Darmstadt: Steinkopf-Verlag 1997, ISBN 3-7985-1087-3, page 282, formula 8.3b. The definition of the weight average particle size diameter D w according to this formula is the following:
D w =sum( n i *D i 4 )/sum( n i *D i 3 )
n i : number of particles with the diameter D i .
The summation is performed from the smallest to largest diameter of the particles size distribution. It should be mentioned that for a particles sire distribution of particles with the same density which is the case for the rubber latices (B1) and (B2) the volume average particle size diameter D v is equal to the weight average particle size diameter D w . The calculations of the average diameters were performed by means of the Mie theory.
The values indicated for the gel content are based on the determination according to the wire cage method in toluene (see Houben-Weyl, Methoden der Organischen Chemie, Makromolekulare Stoffe, part 1, page 307 (1961) Thieme Verlag Stuttgart). The gel contents of the starting rubber latices can be adjusted in a manner known in principle by applying suitable reaction conditions (e.g., high reaction temperature and/or polymerization up to high conversion as well as, optionally, addition of substances with a cross-linking effect for achieving a high gel content, or, e.g., low reaction temperature and/or termination of the polymerization reaction prior to the occurrence of a cross-linkage that is too comprehensive as well as, optionally, addition of molecular-weight regulators such as, for example n-dodecylmercaptan or tert-dodecylmercaptan for achieving a low gel content).
As emulsifiers there may be used conventional anionic emulsifiers such as alkyl sulfates, alkyl sulfonates, aralkyl sulfonates, soaps of saturated or unsaturated fatty acids as well as resin acid-based emulsifiers or tall resin emulsifiers. It is also possible in principle to use emulsifiers having carboxyl groups (e.g. salts of C10-C18 fatty acids, emulsifiers according to DE-A 36 39 904 and DE-A 39 13 509), Resin acid-based emulsifiers or tall resin emulsifier or emulsifiers according to DE-A 39 13 509 are used preferably. As resin or rosin acid-based emulsifiers, those are being used in particular for the production of the butadiene rubber latices (B1) and (B2) by emulsion polymerization that contain alkaline salts of the rosin acids. Salts of the resin acids are also known as rosin soaps. Examples include alkaline soaps as sodium or potassium salts from disproportionated and/or dehydrated and/or hydrated and/or partially hydrated gum rosin with a content of dehydroabietic acid of at least 30% by wt. and preferably a content of abietic acid of maximally 1% by wt. Furthermore, alkaline soaps as sodium or potassium salts of tall resins or tall oils can be used with a content of dehydroabietic acid of preferably at least 30% by wt., a content of abietic acid of preferably maximally 1% by wt. and a fatty acid content of preferably less than 1% by wt. Mixtures of the aforementioned emulsifiers can also be used for the production of the butadiene rubber latices (B1) and (B2). The use of alkaline soaps as sodium or potassium salts from disproportionated and/or dehydrated and/or hydrated and/or partially hydrated gum rosin with a content of dehydroabietic acid of at least 30% by wt. and a content of abietic acid of maximally 1% by wt. is advantageous.
Suitable molecular-weight regulators for the production of the butadiene rubber latices (B1) and (B2) include, for example, alkylmercaptans, such as n-dodecylmercaptan, tert-dodecylmercaptan, dimeric alpha-methylstyrene and terpinolene.
Inorganic and organic peroxides, e.g. hydrogen peroxide, di-tert-butylperoxide, cumene hydroperoxide, dicyclohexylpercarbonate, tent-butylhydroperoxide, p-menthanehydroperoxide, azo initiators such as azobisisobutyronitrile, inorganic per-salts such as ammonium, sodium or potassium persulfate, potassium perphosphate, sodium perborate as well as redox systems can be taken into consideration as initiators of the emulsion polymerization of butadiene or a mixture of butadiene and one or more monomers that are copolymerizable with butadiene as above mentioned. Redox systems generally consist of an organic oxidizing agent and a reducing agent, and additional heavy-metal ions can be present in the reaction medium (see Houben-Weyl, Methoden der Organischen Chemie, volume 14/1, pp. 26-297).
Moreover, salts, acids and bases can be used in the emulsion polymerization for producing the butadiene rubber latices. With acids and bases the pH value, with salts the viscosity of the latices is adjusted during the emulsion polymerisation. Examples for acids include sulfuric acid, hydrochloric acid, phosphoric acid; examples for bases include sodium hydroxide solution, potassium hydroxide solution; examples for salts include chlorides, sulfates, phosphates as sodium or potassium salts. The preferred base is sodium hydroxide solution and the preferred salt is tetrasodium pyrophosphate. The pH value of the butadiene rubber latices is between pH 7 and pH 13, preferably between 8 and pH 12, particularly preferably between pH 9 and pH 12.
Polymerization temperature in the preparation of the starting rubber latices is generally 25° C. to 160° C., preferably 40° C. to 90° C., Work can be carried out under the usual temperature control, e.g. isothermally. It is also possible to carry out polymerization in such a way that the temperature difference between the beginning and the end of the reaction is at least 2° C., or at least 5° C., or at least 10° C. starting with a lower temperature.
It is possible to first provide all substances used, i.e. seed latex, water, monomers, emulsifiers, molecular-weight regulators, initiators, bases, acids and salts at the beginning of polymerization. Furthermore, it is also possible to first provide only the seed latex and a part of the substances used at the beginning of the polymerization, and to first provide other substances used only partially, and to feed the remaining part during the polymerization.
After the polymerization is finished the butadiene rubber latices (B1) and (B2) can be cooled down to 50° C. or lower and as far as the monomer conversion is not completed the not reacted monomers, e.g. butadiene can be removed by devolatilization at reduced pressure if necessary.
The solid content of the butadiene rubber latices (B1) and (B2) is preferably 25 to 60% by wt. (evaporation sample at 180° C. for 25 min. in drying cabinet), more preferably 30 to 55% by wt., particularly preferably 35 to 50% by wt. The degree of conversion (calculated from the solid content of a sample and the mass of the substances used) of the monomers used in the emulsion polymerization preferably is larger than 50%, more preferably larger than 60%, particularly preferably larger than 70%, very particularly preferably larger than 80%, in each case based on the sum of monomers. Moreover, the degree or conversion of the monomers used is preferably lower than 99%, more preferably lower than 97%, particularly preferably lower than 96%, very particularly preferably lower than 95%, in each case based on the sum of monomers.
According to the present invention in the preparation of the graft rubber copolymers B) at least two rubber latices, comprising butadiene rubber latices (B1) and (B2) are used. This means that in addition to the butadiene rubber latices (B1) and (B2) other butadiene rubber latices may be used that do not meet the definition of butadiene rubber latices (B1) and (B2). Such additional butadiene rubber latices may be used for example in an amount of up to 20% by weight based on the total amount of all butadiene rubber latices used in the preparation of a graft rubber copolymer B). In a preferred embodiment, however, only the butadiene rubber latices (B1) and (B2) are used in the preparation of a graft rubber copolymer B). Or with other words the rubber latices used to prepare the of graft rubber copolymer B) consist of butadiene rubber latex polymer (B1) and butadiene rubber latex polymer (B2).
Graft Rubber Copolymers B)
The preparation of the graft rubber copolymers B) obtained according to the invention may be carried out, as desired, either by separately grafting the butadiene rubber the butadiene rubber latices (B1) and (B2) and subsequently mixing the graft rubber copolymers B) obtained, or, preferably, however, by common grafting of the butadiene rubber latices (B1) and (B2) and optionally present other butadiene rubber latices during one reaction. The graft polymerization(s) may be carried out according to any desired processes; it/they is/are preferably so carried out that the monomer mixture is added continuously to a mixture of the butadiene rubber latices (B1) and (B2), and polymerization is carried out. Preferred is the common grafting of a mixture of the butadiene rubber latices (B1) and (B2) during one reaction.
For the preferred common grafting of a mixture of the butadiene rubber latices (B1) and (B2) during one reaction the weight median particle diameter D 50 of the mixture of the butadiene rubber latices (B1) and (B2) is larger than 350 nm, preferably larger than 355 nm and particularly preferably larger than 360 nm. The weight median particle diameter D 50 of the mixture of the butadiene rubber latices (B1) and (B2) is less than 1000 nm, preferably less than 800 nm, most preferably less than 500 nm.
The amount of the butadiene rubber latex polymer (B1) in the graft polymer B is 1 to 49% by wt. (B1) and the amount of the butadiene rubber latex polymer (B2) is 51 to 99% by wt. The amount of the butadiene rubber latex polymer (B1) in the graft polymer B is preferably 10 to 40% by wt. (B1) and the amount of the butadiene rubber latex polymer (B2) is preferably 60 to 90% by wt. The amount of the butadiene rubber latex polymer (B1) in the graft polymer B is particularly preferably 15 to 35% by wt. (B1) and the amount of the butadiene rubber latex polymer (B2) is particularly preferably 65 to 85% by wt.
Particular monomer/rubber ratios are preferably maintained, and the monomers are added to the rubber in a known manner: In order to produce graft rubber copolymers B) according to the invention preferably from 15 to 60 parts by weight, particularly preferably from 20 to 50 parts by weight, of a mixture of styrene and acrylonitrile, which may optionally contain up to 50 wt. % (based on the total amount of monomers used in the graft polymerization) of one or more comonomers, are polymerized in the presence of preferably from 40 to 85 parts by weight, particularly preferably from 50 to 80 parts by weight (in each case based on solid), of the butadiene rubber latices (B1) or (B2) or of a mixture of butadiene rubber latices (B1) and (B2). The monomers used in the graft polymerization are preferably mixtures of styrene and acrylonitrile in a weight ratio of from 95:5 to 50:50, particularly preferably in a weight ratio of from 80:20 to 65:35, it being possible for styrene and/or acrylonitrile to be replaced wholly or partially, preferably partially, by copolymerizable monomers, preferably by alpha-methylstyrene, methyl methacrylate, maleic anhydride or N-phenylmaleimide. In principle, any desired further copolymerizable vinyl monomer as mentioned before may be used in addition to styrene and acrylonitrile, in amounts of up to preferably approximately 10 wt. % (based on the total amount of monomers that are grafted). Most preferred is the use of solely styrene and acrylonitrile as graft monomers.
Molecular-weight regulators may additionally be used in the graft polymerization, preferably in amounts of from 0.01 to 2 wt. %, particularly preferably in amounts of from 0.05 to 1 wt. % (in each case based on the total amount of monomers in the graft polymerization step). Suitable molecular-weight regulators are, for example, alkylmercaptans, such as n-dodecylmercaptan, tert-dodecylmercaptan, dimeric alpha-methylstyrene, terpinols.
Included as initiators are inorganic and organic peroxides, for example hydrogen peroxide, di-tert-butyl peroxide, cumene hydroperoxide, dicyclohexyl percarbonate, tert-butyl hydroperoxide, p-menthane hydroperoxide, azo initiators such as azobisisobutyronitrile, inorganic per-salts such as ammonium, sodium or potassium persulfate, potassium perphosphate, sodium perborate, as well as redox systems. Redox systems generally consist of an organic oxidising agent and a reducing agent, it being possible for heavy metal ions additionally to be present in the reaction medium (see Houben-Weyl, Methoden der Organischen Chemie. Volume 14/1, p. 263 to 297).
In the grafting step as emulsifier there may be used conventional anionic emulsifiers such as alkyl sulfates, alkyl sulfonates, aralkyl sulfonates, soaps of saturated or unsaturated fatty acids as well as above mentioned resin acid-based emulsifiers or tall resin emulsifiers. It is also possible in principle to use emulsifiers having carboxyl groups (e.g. salts of C10-C18 fatty acids, emulsifiers according to DE-A 36 39 904 and DE-A 39 13 509). Resin acid-based emulsifiers or tall resin emulsifier are used preferably.
The polymerization temperature is generally from 25° C. to 160° C., preferably from 40° C. to 90° C. The operation may be carried out with conventional temperature management, for example isothermally; however, the graft polymerization is preferably carried out in such a manner that the temperature difference between the beginning and the end of the reaction is at least 10° C., preferably at least 15° C. and particularly preferably at least 20° C., starting at lower temperatures.
In order to produce the graft rubber polymers according to the invention, the graft polymerization may preferably be carried out by feeding in the monomers in such a manner that from 55 to 90 wt. %, preferably from 60 to 80 wt. % and particularly preferably from 65 to 75 wt. %, of the total monomers to be used in the graft polymerization are metered in in the first half of the total monomer metering time; the remaining amount of monomers is metered in in the second half of the total monomer metering time. It is also possible to provide first up to 30 wt. % of the total monomers together with the butadiene rubber latices (B1) or (B2) or mixtures of the butadiene rubber latices (B1) and (B2) and to feed the remaining amount of monomers continuously or in the above described manner.
The work-up of the graft rubber polymers is carried out by common procedures, e.g. by coagulation with salts, e.g. magnesium sulfate and/or acids, washing, drying or by spray drying.
Component C)
The composition may optionally comprise, as a further component C) at least one or more (co)polymer of at least one monomer selected from the group consisting of vinyl aromatic monomers, vinyl cyanides and unsaturated carboxylic acids and derivatives thereof, in particular, (co)polymers of at least one monomer from the group consisting of vinyl aromatics, vinyl cyanides (unsaturated nitrites), (meth)acrylic acid (C 1 to C 8 )-alkyl esters, unsaturated carboxylic acids and derivatives (such as anhydrides and imides) of unsaturated carboxylic acids.
(Co)polymers C) which are particularly suitable are those of
C.1 50 to 99 wt. %, preferably 65 to 85 wt. %, particularly preferably 70 to 80 wt. %, based on (co)polymer C), of at least one monomer selected from the group consisting of vinylaromatics (such as, for example, styrene, α-methylstyrene), nucleus-substituted vinylaromatics (such as, for example, p-methylstyrene, p-chlorostyrene) and (meth)acrylic acid (C 1 -C 8 )-alkyl esters (such as, for example, methyl methacrylate, n-butyl acrylate, tert-butyl acrylate) and
C.2 1 to 50 wt. %, preferably 15 to 35 wt. %, particularly preferably 20 to 30 wt. %, based on (co)polymer C), of at least one monomer selected from the group consisting of vinyl cyanides (such as, for example, unsaturated nitriles, such as acrylonitrile and methacrylonitrile), (meth)acrylic acid (C 1 -C 8 )-alkyl esters (such as, for example, methyl methacrylate, n-butyl acrylate, tert-butyl acrylate), unsaturated carboxylic acids and derivatives of unsaturated carboxylic acids (for example maleic anhydride and N-phenyl-maleimide), with the proviso that C.1 differs from C.2.
The (co)polymers C) are normally resinous, thermoplastic, and rubber-free. The copolymer of C.1 styrene and C.2 acrylonitrile is particularly preferred. Such (co)polymers C) are known and may be prepared by free-radical polymerization, in particular by emulsion, suspension, solution or bulk polymerization. The (co)polymers C) preferably have average molecular weights Mw (weight-average, determined by gel permeation chromatography (using in particular polystyrene as a standard) of between 50,000 and 200,000 g/mol, preferably between 80,000 and 200,000 g/mol, particularly preferably between 100,000 and 200,000 g/mol.
As mentioned above such (co)polymers as component C) may be contained in an amount of preferably up to 50 wt.-% based on the total amount of the resin composition.
Component D)
The composition may moreover comprise further conventional polymer additives (component D), such as those selected from the group of stabilizers (for example antioxidants, UV stabilizers, peroxide destroyers), flame retarding or flameproofing agents, flameproofing synergists, antidripping agents (for example compounds of the substance classes of fluorinated polyolefins, silicones and aramid fibers), lubricants and mold release agents (for example pentaerythritol tetrastearate), nucleating agents, antistatics, fillers and reinforcing substances (for example glass fibers or carbon fibers, mica, kaolin, talc, CaCO 3 and glass flakes) as well as dyestuffs and pigments. As mentioned above such conventional polymer additives may be contained in an amount of preferably up to 25 wt.-% based on the total amount of the resin composition.
The present invention further relates to a process for the manufacture of the resin composition according to the invention, comprising the steps of:
a) Preparing at least one graft rubber copolymer B) by emulsion polymerization of styrene and acrylonitrile in the weight ratio 95:5 to 50:50, whereby styrene and/or acrylonitrile wholly or partially can be replaced by copolymerizable monomers, onto at least two rubber latices, comprising: a butadiene rubber latex (B1) having a weight median particle diameter D 50 of 100 to 250 nm, and a gel content from 30 to 80% by weight, and a butadiene rubber latex (B2) having a weight median particle diameter D 50 of more than 350 nm, and a gel content of less than 75% by weight, preferably less than 70% by weight, b) Admixing the graft rubber copolymer B) obtained in step a) with at least one aromatic polycarbonate A) and optionally 0 to 50 wt.-parts of one or more (co)polymer of at least one monomer selected from the group consisting of vinyl aromatic monomers, vinyl cyanides and unsaturated carboxylic acids and derivatives thereof, optionally 0 to 25 wt.-parts of conventional polymer additives.
Preparation of the Moulding Compositions and Shaped Articles
The present invention further relates to a process for the preparation of moulding compositions and/or shaped articles from the resin composition according to the invention.
Thermoplastic molding compositions according to the invention may be prepared from the resin composition of the present invention for example by mixing the particular constituents in a known manner and subjecting the mixture to melt compounding and melt extrusion at temperatures of from 200° C. to 300° C. in conventional units, such as internal kneaders, extruders and twin-shaft screws. The mixing of the individual constituents may be carried out in a known manner either successively or simultaneously, and in particular either at about 20° C. (room temperature) or at a higher temperature. In a preferred embodiment, optional component C) or a part amount of component C) is added to component B) or a part amount of component B) to give a precompound. The present invention therefore also provides compositions wherein at least one graft rubber copolymer B) or a part amount thereof and at least one of the optional components C) or a part amount of component C) are employed in the form of a precompound prepared by compounding of them. A precompound of a graft polymer according to component B) prepared in the emulsion polymerization process and a copolymer according to component C) or a part amount of component C) is particularly preferably employed, in a preferred embodiment this precompound being prepared by mixing the two components B) and C) in the melt at temperatures of from 200 to 260° C. with application of a vacuum, in a particularly preferred embodiment, in the first step graft polymer B or a part amount of component B) is mixed with component C) or a part amount of component C) by means of compounding with vacuum devolatilization to give a low-emission precompound. It is particularly advantageous to employ component B) in the moist state (i.e. in the presence of water) in this davolatilizing compounding in accordance with the process which is described in EP 0 768 157 A1 and EP 0 867 463 A1. Precompounds in which the total content of volatile organic compounds is less than 400 mg/kg, preferably less than 300 mg/kg, in particular less than 200 mg/kg are particularly suitable. In the second process step, the remaining constituents and the precompound are mixed in a known manner and the mixture is subjected to melt compounding or melt extrusion at temperatures of from 200° C. to 300° C. in conventional units, such as internal kneaders, extruders and twin-shaft screws. In a preferred embodiment, a reduced pressure of <500 mbar, preferably <150 mbar, in particular <100 mbar is applied during this second compounding step for the purpose of further devolatilization of volatile constituents (such as e.g. residual monomers and residual solvent). The present invention therefore also provides a process for the preparation of low-emission compositions according to the invention. The molding compositions according to the invention may be used for the production of all types of shaped articles. These may be produced by injection molding, extrusion and the blow molding process. A further form of processing is the production of shaped articles by thermoforming from previously produced sheets or films. Examples of such shaped articles are films, profiles, housing parts of all types, e.g. for domestic appliances, such as juice presses, coffee machines, mixers; for office machines, such as monitors, flat screens, notebooks, printers, copiers; sheets, pipes, electrical installation conduits, windows, doors and further profiles for the construction sector (interior finishing and exterior uses) as well as electrical and electronic components, such as switches, plugs and sockets, as well as vehicle body and interior components utility vehicles, in particular for the automobile sector. The molding compositions according to the invention may also be used in particular, for example, for the production of the following shaped articles or moldings: interior finishing parts for track vehicles, ships, aircraft, busses and other motor vehicles, housings of electrical equipment containing small transformers, housings for equipment for processing and transmission of information, housings and facings for medical equipment, massage equipment and housings therefor, toy vehicles for children, flat wall elements, housings for safety equipment, thermally insulated transportation containers, moldings for sanitary and bath fittings, cover gratings for ventilator openings and housings for garden equipment.
The invention is further illustrated but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified.
EXAMPLES
For measuring the weight average particle size D w and the weight median particle diameter D 50 with the disc centrifuge DC 24000 by CPS Instruments Inc. equipped with a low density disc, an aqueous sugar solution of 17.1 mL with a density gradient of 8 to 20% by wt. of saccharose in the centrifuge disc was used, in order to achieve a stable flotation behavior of the particles. A polybutadiene latex with a narrow distribution and a particle size of 405 nm (determined by electron microscopy) was used for calibration. The measurements were carried out at a rotational speed of the disc of 24,000 r.p.m. by injecting 0.1 mL of a diluted rubber dispersion prepared in an aqueous 24% by wt. saccharose solution into the disc containing the aqueous sugar solution with a density gradient of 8 to 20% by wt. of saccharose. The calculation of the weight average particle size D w and the weight median particle diameter D 50 was performed by means of the Mie theory.
Component A)
Polycarbonate manufactured from bisphenol A and phosgene with a weight average molecular weight of 27,500 g/mol (measured by GPC in methylene chloride at 25° C.).
Component B)
Rubber Latices
Rubber Latex B1
The rubber latex B1 is produced by emulsion polymerization of butadiene using sodium rosin soap as emulsifier and by means of a butadiene seed latex with diameter D 50 of 47 nm. The final rubber latex B1 has a D 50 of 188 nm and D w of 183 nm. The gel content is 71 wt.-.%.
Rubber Latex B2
The rubber latex B2 is produced by emulsion polymerization of butadiene using an emulsifier according to DE-A 39 13 509, table 1, Nr.1 and by means of a butadiene seed latex with diameter D 50 of 119 nm, The final rubber latex B2 has a D 50 of 365 nm and D w of 364 nm. The gel content is 67 wt.-%.
A 25:75 mixture by weight of B1 and B2 according to the invention (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) has a D 50 of 361 nm and D w of 323 nm; a 50:50 mixture by weight of B1 and B2 which is not according to the invention has a D 50 of 210 nm and D w of 273 nm. The rubber latices B1 and B2 are mixed by stirring according to the weight ratios above before the measurements of the particles sizes are carried out with a disc centrifuge DC 24000 by CPS Instruments Inc.
Rubber Latex B3 (for Comparison Trials)
The rubber latex B3 is produced by emulsion polymerization of butadiene using sodium rosin soap as emulsifier and by means of a butadiene seed latex with diameter D 50 of 47 nm. The final rubber latex B3 has a D 50 of 119 nm and D w of 117 nm. The gel content is 88 wt.-%.
Rubber Latex B4 (for Comparison Trials)
The rubber latex B4 is produced by emulsion polymerization of butadiene using an emulsifier according to DE-A 39 13 509, table I, Nr.1 and by means of a butadiene seed latex with diameter D 50 of 47 nm. The final rubber latex B4 has a D 50 of 294 nm and D w of 288 nm. The gel content is 53 wt.-%.
Rubber Latex B5 (for Comparison Trials)
The rubber latex B5 is produced by emulsion polymerization of butadiene using an emulsifier according to DE-A 39 13 509, table I, Nr.1 and by means of a butadiene seed latex with diameter D 50 of 47 nm. The final rubber latex B5 has a D 50 of 294 nm and D w of 288 nm. The gel content is 71 wt.-%.
Rubber Latex B6 (for Comparison Trials)
The rubber latex B6 is produced by emulsion polymerization of butadiene using an emulsifier according to DE-A 39 13 509, table I, Nr. 1 and by means of a butadiene seed latex with diameter D 50 of 47 nm. The final rubber latex B5 has a D 50 of 376 nm and D w of 367 nm. The gel content is 79 wt.-%.
Graft Polymer B-1
A mixture of 15 wt.-parts of the rubber latex B1 and 45 wt.-parts of the rubber latex B2 corresponding to a weight ratio of B1 to B2 of 25:75—(based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile based on the total amount of the monomers are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-1 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet to obtain the graft polymer B-1 according to the invention.
Graft Polymer B-2
A mixture of 15 wt.-parts of the rubber latex B1 and 45 wt.-parts of the rubber latex B2 corresponding to a weight ratio of B1 to B2 of 25:75 (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile and 0.16 wt.-parts of tert.-dodecylmercaptane are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert.-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-2 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet. Graft polymer B-2 according to the invention is obtained.
Graft Polymer B-3
In a similar way to the graft latex B-1 a mixture of 15 wt.-parts of the rubber latex B1 and 45 wt.-parts of the rubber latex B2 corresponding to a weight ratio of B1 to B2 of 25:75—(based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex, Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of potassium persulfate as well as an aqueous solution of Brueggolite®FF6 M from Brueggemann Chemical as reducing agent is fed in 8 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-3 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet. Graft polymer B-3 according to the invention is obtained.
Graft Polymer B-4
In a similar way to B-3 a mixture of 15 wt.-parts of the rubber latex B1 and 45 wt.-parts of the rubber latex B2 corresponding to a weight ratio of B1 to B2 of 25:75 (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile and 0.16 wt.-parts of tert.-dodecylmercaptane are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of potassium persulfate as well as an aqueous solution of Brueggolite®FF6 M from Brueggemann Chemical as reducing agent is fed in 8 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-4 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet. Graft polymer B-4 according to the invention is obtained.
Graft Polymer B-5 (for Comparison Trials)
A mixture of 30 wt.-parts of the rubber latex B1 and 30 wt.-parts of the rubber latex B2 corresponding to a weight ratio of 50:50 (D 50 =210 nm) (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert.-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours, The graft latex B-5 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet to obtain the graft polymer B-5.
Graft Polymer B-6 (for Comparison Trials)
60 wt.-parts of the rubber latex B1 (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert.-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-6 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet to obtain the graft polymer B-6.
Graft Polymer B-7 (for Comparison Trials)
60 wt.-parts of the rubber latex B2 (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-7 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet to obtain the graft polymer B-7.
Graft Polymer B-8 (for Comparison Trials)
A mixture of 30 wt.-parts of the rubber latex B1, 15 wt.-parts of the rubber latex B2 (D50 of the mixture of B1 and B2<210 nm) and 15 wt.-parts of the rubber latex B5 (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert.-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-8 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70′C. in a drying cabinet to obtain the graft polymer B-8.
Graft Polymer B-9 (for Comparison Trials)
60 wt.-parts of the rubber latex B3 (based on solids, evaporation sample at 180° C. for 25 min. In drying cabinet) is adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert.-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours, The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-10 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet to obtain the graft polymer B-9.
Graft Polymer B-10 (for Comparison Trials)
A mixture of 15 wt.-parts of the rubber latex B4 and 45 wt.-parts of the rubber latex B6 (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert.-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-11 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet to obtain the graft polymer B-10.
Graft Polymer B-11 (for Comparison Trials)
A mixture of 15 wt.-parts of the rubber latex B1 and 45 wt.-parts of the rubber latex B6 (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca. 30 wt.-% and heated to 59° C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert.-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-12 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet to obtain the graft polymer B-11.
Graft Polymer B-12 (for Comparison Trials)
A mixture of 18 wt.-parts of the rubber latex B3 and 42 wt.-parts of the rubber latex B2 (based on solids, evaporation sample at 180° C. for 25 min. in drying cabinet) is mixed and adjusted with water to a solid content of ca. 30 wt.-% and heated to 59′C. After this 40 wt.-parts of a mixture of 74.5 wt.-% styrene and 25.5 wt.-% acrylonitrile are fed continuously within 4 hours to the provided rubber latex. Starting with the monomer feed an aqueous sodium rosin soap solution is fed in 5 hours and an aqueous solution of tert.-butylhydroperoxide as well as an aqueous solution of sodium ascorbate is fed in 9 hours. The temperature is increased within 4 hours from 59° C. to 81° C. and kept in the range of 78 to 81° C. for further 8 hours. The graft latex B-13 is stabilized with 0.8 wt.-% of a phenolic antioxidant and coagulated with a mixture of magnesium sulfate and acetic acid, washed with water and dried at 70° C. in a drying cabinet to obtain the graft polymer B-12.
Component C-1
Statistical copolymer from styrene and acrylonitrile with a ratio of polymerized styrene to acrylonitrile of 76.5:23.5 with a weight average molecular weight Mw of ca. 145,000 g/mol, a polydispersity of M w /M n <3 and a melt flow rate (MVR) at 220° C./10 kg of 40 mL/10 minutes, produced by free radical solution polymerization.
Additives
D1: Pentaerythrityl tetrastearate D2: Phosphite stabilizer Irganox® B900 from BASF D3: Phenolic antioxidans Irganox® 1076 from BASF D4: citric acid
EXAMPLES
The PC/ABS compounds are mixed on a twin-screw-extruder with a shaft diameter of 25 mm. The temperature zones in the extruder were set to 220° C. to 250° C. (extrusion zone) and the twin-screw-extruder was processed at 480 rpm, The batch size for all examples was 4 kg.
In the following tables the compositions in wt.-part and the test results are summarized.
The following tests were performed with the thermoplastic resins: melt volume rate MVR at 260° C. and 5 kg load [mL/10 min] according to ISO 1133, ball indentation (Hc) [N/mm 2 ] according to ISO 2039-1(test load 358 N, test duration 30 sec.), notched Izod impact strength [kJ/m 2 ] according to ISO 180-1A at different temperatures, Vicat softening temperatures B/120 (50N, 120° C./h) according to ISO 306. The hydrolytic stability is tested by change of the MVR at 260° C. and 5 kg load [mL/10 min] according to ISO 1133 after storage of the pellets at 95° C. and 100% relative humidity. The increase of the MVR is reported in [mL/10 min]. The processing stability is tested by measuring the MVR at 300° C. and 5 kg load [mL/10 min] according to ISO 1133 after the melt was stored for 15 min under the absence of oxygen. Lower values of the hydrolytic and processing stability result in better stability.
Example
1
2
3
4
5
6
7
8
9
10
11
Inven-
Inven-
Inven-
Inven-
compar-
compar-
compar-
compar-
compar-
compar-
compar-
tive
tive
tive
tive
ative
ative
ative
ative
ative
ative
ative
exam-
exam-
exam-
exam-
exam-
exam-
exam-
exam-
exam-
exam-
exam-
ple
ple
ple
ple
ple
ple
ple
ple
ple
ple
ple
Component A
43
43
43
43
43
43
43
43
43
43
43
Graft polymer B-1
25.5
Graft polymer B-2
25.5
Graft polymer B-3
25.5
Graft polymer B-4
25.5
Graft polymer B-5
25.5
Graft polymer B-6
6.38
Graft polymer B-7
19.12
Graft polymer B-8
25.5
Graft polymer B-9
6.38
Graft polymer B-10
19.12
25.5
Graft polymer B-11
25.5
Graft polymer B-12
25.5
Component C-1
31.5
31.5
31.5
31.5
31.5
31.5
31.5
31.5
31.5
31.5
31.5
Component D1
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
Component D2
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
Component D3
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
notched Izod impact
strength
@ RT [kJ/m 2 ]
40.8
44.6
45.2
45.2
41.6
40.9
41.1
33.9
38.4
36.3
39.7
@ −30° C. [kJ/m 2 ]
32.9
36.7
37.2
36.1
32.8
32.4
31.8
28.9
29.1
36.3
35.7
@ −40° C. [kJ/m 2 ]
34.1
39.4
35.2
34.9
31.8
31.0
29.7
21.4
23.8
24.4
32.5
Vicat B/120 [° C.]
110
106
110.3
110
110
111
109
108
110
110
108
MVR 260° C./5 kg
8.7
19.9
14.3
15.5
8.7
9.3
10.5
10.0
15.8
15.5
7.8
[mL/10 min]
ball indentation
87
85
94
95
108
87
86
85
93
87
84
(Hc) [N/mm 2 ]
Hydrolytic stability
7.2
— (nd)
9.7
10.5
5.8
5.4
6.5
7.7
12.1
12.2
6.6
Delta MVR [mL/10 min]
Processing stability
75
— (nd)
72
87
49
62
41
50
86
90
34
MVR 300° C./5 kg
[mL/10 min]
Example
12
13
14
15
16
17
18
19
20
21
22
Inven-
compar-
compar-
Inven-
compar-
compar-
compar-
compar-
compar-
compar-
compar-
tive
ative
ative
tive
ative
ative
ative
ative
ative
ative
ative
exam-
exam-
exam-
exam-
exam-
exam-
exam-
exam-
exam-
exam-
exam-
ple
ple
ple
ple
ple
ple
ple
ple
ple
ple
ple
Component A
58
58
58
70
70
70
70
70
70
70
70
Graft polymer t B-1
18.75
13.5
Graft polymer B-5
18.75
13.5
Graft polymer B-6
4.89
3.38
Graft polymer B-7
14.06
10.12
Graft polymer B-8
13.5
Graft polymer B-9
3.375
Graft polymer B-10
10.125
13.5
Graft polymer B-11
13.5
Graft polymer B-12
13.5
Component C-1
32.25
32.25
32.25
16.5
16.5
16.5
16.5
16.5
16.5
16.5
16.5
Component D1
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
Component D2
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
Component D3
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
Component D4
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
notched Izod impact
strength
@ RT [kJ/m 2 ]
46.8
47.2
46.9
52.0
51.8
53.4
45.2
46.8
48.6
45.8
46.8
@ −30° C. [kJ/m 2 ]
37.3
38.4
37.2
40.9
40.1
40.5
27.6
34.1
41.1
30.2
41.2
@ −40° C. [kJ/m 2 ]
37.3
36.2
35.8
45.7
34.3
37.0
23.4
25.1
26.3
24.1
24.2
Vicat B/120 [° C.]
120
121
121
131
131
132
127
128
130
129
126
MVR 260° C./5 kg
10.7
9.8
10.9
11.2
11.9
11.7
16.8
16.3
17.5
17.7
16.0
[mL/10 min]
ball indentation
98
99
98
104
105
104
103
102
103
103
99
(Hc) [N/mm 2]
Hydrolytic stability
10.0
10.0
9.7
—
—
—
—
—
—
—
—
Delta MVR [mL/10 min)
|
The invention relates to thermoplastic polycarbonate compositions which are impact-modified with ABS type polymers, said polycarbonate compositions being impact-modified with ABS type polymers are characterized by their excellent low temperature ductility, good processing properties expressed by relatively high melt volume rate (MVR) and good hydrolytic stability.
| 2
|
FIELD OF THE INVENTION
[0001] The present invention relates to profile scanning for locating an attachment zone of a vessel for attaching a mooring robot to the vessel.
BACKGROUND ART
[0002] Various systems are known in the art for assisting with the traditionally manual procedure of docking a vessel for loading and unloading. For example, Japanese Patent Publication No. 2000292540 describes a system to provide such a means that can measure the berthing speed of a vessel by automatically detecting the vessel, at a low cost with a relatively simple constitution. A laser sensor installed to a quay is mounted on a turntable for controlling the direction of the sensor and, at the time of scanning, the turntable changes the angle of the sensor in the vertical direction within the laser beam axis moving range between a laser beam irradiation axis along which the position of a vessel can be detected at high tide and another laser beam irradiation axis along which the position of the vessel can be detected at low tide so that the sensor may detect the vessel by changing the laser beam irradiation axis of the sensor even when the position of the vessel changes in the vertical direction. Then the berthing speed of the vessel is measured by fixing the laser beam irradiation axis at the position at which the sensor detects the vessel. When the measurement is omitted while the vessel comes alongside the quay, the position of the vessel is detected by again moving the sensor.
[0003] In a further example U.S. Pat. No. 6,023,665 describes a system for detecting, identifying and docking aircraft using laser pulses to obtain a profile of an object in the distance. The system initially scans the area in front of the gate until it locates and identifies an object. Once the identity of the object is known, the system tracks the object. By using the information from the profile, the system can in real time display the type of airplane, the distance from the stopping point and the lateral position of the airplane.
[0004] In still a further example Japanese Patent Publication No. 4303706 describes a system to detect the position of a ship which is changed by the ebb and flow of tide and the amount of unloading of bulk material in the unloading work of the ship in real time without contact and without much effort. A laser range finder is attached to cargo handling equipment such an unloader. A light beam is made to scan up and down toward a ship which is approaching a pier. Among the results of the measurements of distances, the value indicating the shortest distance becomes the distance to the corner part of broadside of the ship. Therefore, the horizontal distance and the vertical distance of the ship with respect to the cargo handling equipment can be computed based on the distance and the up and down angle of the beam. When the cargo handling equipment is controlled with the horizontal distance and the vertical distance as the operating data, the equipment can be operated so that the scraping part at the tip of the cargo handling equipment and the like do not hit the bottom of the ship.
[0005] In still a further example U.S. Pat. No. 3,594,716 describes a system where a vessel docking system employs transmitting and receiving transducers for developing Doppler frequency shifted signals indicative of velocity components along particular ship's axes. The signals are converted to digital form, and processed to yield speed and direction information along the sensed axes. The velocity information is corrected to compensate for variations in the acoustical propagating characteristic of the ocean medium.
[0006] In still a further example U.S. Pat. No. 3,690,767 describes a docking system for large ocean-going vessels, which comprises a laser pulse range radar system having a laser transmitter and receiver, a retroreflector, and receiving and transmitting optics. Two such systems are disposed on a dock. The retroreflectors are disposed on the bow and stern of a vessel. The laser systems share a time interval meter, a computer, and a display panel. The lasers track the retroreflectors as the ship approaches the dock, and the time interval between the transmitted and received pulses is measured. Computations are made and the velocity of the approaching vessel, its distance from the dock, and the vessel position with reference to the dock are continually displayed. This information is then transmitted to the ship's captain.
[0007] In still a further example U.S. Pat. No. 3,707,717 describes a system that has been provided for generating correction command signals relative to the berthing velocity profile of a vehicle in approach of a docking position. A doppler radar system including a radar transceiver projects signals between the docking position and the vehicle and respondingly generates doppler shift frequency signals indicative of the velocity of the vehicle and the relative displacement thereof. A radar counter having preset initial counts stored therein indicative of anticipated initial berthing conditions, responds to the frequency shift signals by counting down from the initial counts in accordance with the doppler shift. Means is included for updating the radar counter in accordance with actual conditions and includes a sonic detector which periodically projects sonic signals between the vehicle and the docking position and respondingly generates corrected count signals in accordance with the reflected sonic energy, indicative of actual distance of the vehicle to the docking position. Means is utilized which periodically transfers the corrected count signals to the radar counter, correcting for errors between actual and preset initial conditions. A velocity profile generator responds to the radar counter output and generates a programmed desired berthing velocity profile which a comparator responds to the velocity profile generator and the counter for generating command signals indicative of any discrepancy between the actual and desired vehicle berthing profile.
[0008] In still a further example U.S. Pat. No. 3,754,247 describes a display apparatus which produces a display of a ship, a line representing an intended berth and indicators whose separation from the berth marker line represents the deviation of the closing rate of an associated part of the ship from a value determined by a function generator which generates an optimum function from signals representing the distance of the part of the ship from the berth.
[0009] In still a further example U.S. Pat. No. 4,340,936 describes a navigational aid system including a microprocessor having peripheral memory devices and being programmed by a read only memory, the system including sensors for measuring variable parameters and thumb switches for inserting known fixed data, and the microprocessor computing from such parameters and data readout data needed for optimum navigation taking into account such factors as leeway and current set and drift, the system having switches to select which data is displayed as the switches are sequentially polled, and the displayed data being accompanied by alpha indicia uniquely identifying each displayed numeric value.
[0010] In still a further example U.S. Pat. No. 5,274,378 describes a relative velocity indicator system for assistance in the docking of vessels uses a radar sensor providing a relative velocity signal indicative of the relative velocity between a ship and a reference, such as a dock. A wireless transmitter associated with the radar sensor receives said relative velocity signal and transmits a signal indicative of said relative velocity signal. A portable receiver and indicator unit carried by the captain of the vessel has a receiver for receiving the transmitted signal and an indicator arranged to receive, from said receiver, a receiver signal indicative of the transmitted signal and, thereby, of the relative velocity signal for indicating the relative velocity between ship and reference.
[0011] In still a further example U.S. Pat. No. 5,432,515 describes a docking information system for assistance in the docking of vessels uses sensors providing information indicative of the relationship between a ship and a reference, such as a dock, a coast line, a river bank, docks, bends and docking areas. A computer coordinates the information. A wireless transmitter associated with the computer transmits signals indicative of the information. A portable receiver and indicator carried by the captain of the vessel has a receiver for receiving the transmitted signals and an indicator screen to display the information. The remote receivers also include fixed monitors on the ship and on shore, and telephones on the ship which communicate with the computer and into the telephone link with shore-based communications.
[0012] In still a further example U.S. Pat. No. 5,969,665, an improved method and apparatus provide a control of the vessel manoeuvring by a determination and displaying of the dangerous relative course zones, wherein the end of the vessel speed-vector should not be located for the object evasion tactic manoeuvring and/or collision avoidance manoeuvring and should be located for the object pursuit and/or interception tactic manoeuvring. The apparatus comprises an object disposition evaluator, a control system, a dangerous criteria setting system, an initial data processor, at least one display and a dangerous relative course zone determiner, including an interface-signal distributor, a logic processor and signal distributor and a data processing system, comprising a trigonometric function processor, a summator, a multiplier-divider and a data processor. The dangerous relative course zones are displayed on at least one indicator, proving the operator with the possibility to evaluate the danger approach situation and instantly select the anti-collision manoeuvre for collision preventive manoeuvring and/or select an optimal manoeuvre for the assigned vessel tactic manoeuvring execution.
[0013] In still a further example U.S. Pat. No. 6,677,889, a auto-docking system has been provided that can automatically dock a ship. The auto-docking system provides a close in radar system and a secondary propulsion system that is under control of a docking processor.
[0014] In still a further example Japanese Patent Publication No. 60-187873 describes a system to achieve automation and labour saving in the operation necessary for alongside pier of a ship by perform a docking operation based on a video and the distance of a target object obtained with a TV camera and a laser distance measuring device set on the ship. A signal processor processes a video signal of a target object taken with a TV camera and a signal of the distance thereof measured with a laser distance measuring device according to a program previously memorized to analyze the positional relationship between the target object and the ship, which enables as accurate determination of the target object in real time. The signal processor also outputs a docking command based on the positional relationship between the target object and the ship while outputting a signal to operate a mooring device such as a winch.
[0015] In still a further example U.S. Pat. No. 4,063,240 describes an electronic docking system utilizing a multiplicity of sensing subsystems to derive and display docking parameters during the docking operation. The parameters displayed include bow and stern velocities ship's velocity perpendicular and parallel to the jetty and ship's orientation to the jetty during the docking manoeuvre. Parameters are derived from data gathered by sensors that include a receive only monopulse and a receive only doppler system which determine the angular position of a selected reference location aboard the ship and a signal with a frequency representative of the ship's velocity from a signal radiated from a beacon antenna aboard the ship. Range measurements are accomplished by utilizing baseband pulse radar systems capable of determining range to accuracies in the order of one foot. A telemetry link between the ship and the shore based system provides a means for simultaneously displaying data on board and on land and for relaying docking commands from the jetty master to the docking pilot.
[0016] It is therefore an object of the present invention to provide a scanning system which overcomes a disadvantage in the prior art or which will at least provide the public with a useful choice.
BRIEF DESCRIPTION OF THE INVENTION
[0017] In a first aspect the present invention consists in a profile scanner for locating a target zone on a profile of a vessel comprising:
[0018] an emitter adapted to progressively or instantaneously radiate towards said vessel;
[0019] a receiver providing a signal indicative of radiation incident thereon;
[0020] a controller or processor including stored instructions, for energising said emitter and receiving said signal, and adapted to determine the vertical location of said target zone relative to scanner.
[0021] Preferably an associated mooring robot or other vessel anchoring systems are located according to said target zone.
[0022] Preferably said mooring robot includes an attachment pad adapted to engage to said target zone.
[0023] In a further aspect the present invention consists in a profile scanner as hereinbefore described wherein said emitter is a laser.
[0024] In a further aspect the present invention consists in a profile scanner as hereinbefore described wherein said controller receives said signal and converts the polar coordinate data contained therein to rectangular coordinates.
[0025] Preferably said rectangular coordinates comprise a cross sectional profile.
[0026] Preferably said controller differentiates said rectangular coordinates to determine a derivative profile.
[0027] Preferably said edges are defined as any portion of said derivative profile over a predetermined threshold.
[0028] Preferably said target zone is between the uppermost edge and any significant intermediate edge.
[0029] Preferably said target zone is a predetermined distance from said intermediate edge.
[0030] In a further aspect the present invention consists in a profile scanner as hereinbefore described wherein said scanner updates said target zone location periodically.
[0031] In a further aspect the present invention consists in a profile scanner as hereinbefore described wherein any one or more selected from the following are also determined from said signal:
gunwale, rubbing strake, and tide level.
[0035] In a further aspect the present invention consists in a mooring robot mounted to a mooring facility, for mooring a floating vessel adjacent said mooring facility, said mooring robot including;
[0036] a suction pad to locate onto the side of said floating vessel,
[0037] actuators to move said suction pad relative to said mooring facility,
[0038] a profile scanner as claimed in any one of the preceding claims to control said actuators to effect at least a controlled vertical positioning of said suction pad.
[0039] In a further aspect the present invention consists in a mooring facility for floating vessels, which includes at least one mooring robot as hereinbefore described.
[0040] In a further aspect the present invention consists in a method of mooring a floating vessel adjacent a mooring facility of a kind as hereinbefore described comprising
operating the profile scanner to scan the hull of a vessel
[0042] allowing any adjustment in the vertical position of said suction pad in response to the profile scanner
[0043] engaging the suction pad to the hull of said vessel
[0044] sucking the suction pad to the hull of said vessel.
[0045] Preferably prior to the sucking of said suction pad, the profile scanner also scans the surface of water adjacent said mooring facility to determine the sea state, wherein the sucking of said suction pad is to a minimum suction pressure correlative to the sea state.
[0046] Preferably prior to engaging said pad to said hull, the profile scanner also scans the surface of water of a tidal body of water adjacent the mooring facility, to allow determination of the state of the tide of said tidal body of water, wherein the vertical positioning of said suction pad is dependent on the state of the tide.
[0047] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.
[0048] The invention consists in the foregoing and also envisages constructions of which the following gives examples only.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] One preferred form of the present invention will now be described with reference to the accompanying drawings in which;
[0050] FIG. 1 is a block diagram showing the system component according to one embodiment of the present invention, and
[0051] FIG. 2 is a flow diagram of the control logic.
DETAILED DESCRIPTION OF THE INVENTION
[0052] The contents of International Patent Application numbers PCT/NZ01/00025, PCT/NZ01/00026, PCT/NZ02/00062, PCT/NZ03/00001 and PCT/NZ03/00167 are incorporated herein by reference.
[0053] In one embodiment now described the present invention relates to a device and method of vertically targeting an attachment pad (e.g. the suction force pad) for a mooring robot onto the side of a vessel. Prior art attempts at vertical targeting relate to the use of tide charts and a lookup table which either identifies the vessel or key attributes of the vessel entered by the operator sighting the vessel in question.
[0054] When a vessel 110 is alongside the mooring facility such as pier 102 and near stationary, the scanner 100 may be employed to detect where an attachment zone 112 suitable to vertically attach the attachment pad (such as a suction pad) of a mooring robot 104 to the ship's hull exists, as shown in FIG. 1 . The scanning occurs prior to the suction pad being attached to the vessel.
[0055] This scanning procedure could be carried out using a “Sick” single line laser radar coupled with a PLC based “PC” used to process the data into a usable format for the control program.
[0056] The Scanner may sweep the side profile of the hull of a vessel 110 to detect for example:
Vessel's gunwale 108 . Target attachment area 112 on the side of the hull. Top of the belting or rubbing strake 114 . Width of the belting or rubbing strake projecting out from the hull. Current tide level 106 .
[0062] With the above information the positional control elements of the mooring robot 104 can be controlled as to enable the positioning of the pad on the vessel at an appropriate location to avoid any protrusions or openings on vessels side.
[0063] In addition to this, the Scanner may also provide the following information for any port authority or shipping operator:
Identification of the actual ship alongside, by comparing it to stored data. Act as a tide gauge to provide feedback on the tide levels and any unusual fluctuations thereof caused by for example tidal waves or storm surge. Establishing arrival and departure draughts of each ship.
[0067] The scanning of tidal height has the benefit of allowing the suction pad to be positioned at a height which is appropriate to the state of the tide. The suction pad mounted from the mooring facility, is usually free running manner in a vertical direction relative to the mooring facility. It may have active control exercised over it in a horizontal plane in order to keep the vessel within a range from a desired location. However free running vertical movement of the suction pad, once attached to the vessel, is required to cater for tidal change and vessel loading changes, which displace the vessel in a vertical direction relative to the mooring facility. The mooring robot will have a limited range or travel of the suction pad in the vertical direction. The suction pad may be mounted on vertical rails which are of a finite length. By determining the state of the tide by the scanner, the position of the suction pad can be controlled, prior to engaging to the vessel to ensure the suction pad is affixed (subject to any detected objects of the hull that may prevent such), to assume a tidal level determined vertical suitable location. For example if the tide is at or near full, the suction pad should be as close as possible (subject to any objects of the hull that may limit such proximity) positioned at or near the upper limit of its travel. A subsequent dropping tide will then allow the suction pad to remain attached for the maximum duration before reaching the lower limit of its travel on its vertical rails.
[0068] Scanning of the water may also allow a determination of the sea state. The information gathered of sea state can be used by the device of the present invention to control specify a suitable suction pressure for the suction pad engagement with the vessel. A rough (i.e. choppy) sea state usually correlates to strong winds. This may require the suction pressure to be set at a level suitable to ensure that the vessel remains securely located adjacent the mooring facility by the robot or robots.
[0069] The scanning may occur during a period immediately prior to mooring of a vessel taking place or may be ongoing to allow the collection and recording of tidal and sea state data.
[0070] Examples of components of the system which may be used to implement the invention will now be described.
1. Hardware
[0071] The present invention in one example is integrated into a PLC based control system, including:
Single line laser profile scanner. PLC “rack” based Multi Vendor Interface (MVI) module.
2. Operation
[0074] The scanning system will provide the “pre-stage” position in the vertical axis for the mooring unit.
[0075] When a vessel is present and close to being in position to moor the operator will press the “pre-stage” button on a Human Machine Interface (HMI).
[0076] When ready the PLC will request data from the scanner. This data will be requested and updated as required by the parameters defined in section 3 .
3. Control Parameters
[0077] A. Maximum Ship to Berth Distance for “Pre-Stage” (mm)
[0078] This parameter is to ensure, that due to the effective range of the scanner, the unit is not looking at the next berth.
[0079] B. Minimum Vertical Target Area Height (mm)
[0080] This is to ensure that if the ship is rising and falling that the distance between the highest point of any lower disposed obstacles such as the rubbing strake or lowest point of the desirable attachment zone, and the lowest point of the highest desirable attachment point or the top of the attachment area defined by for example the gunwale is large enough for the unit to attach to.
[0081] C. Re-Scan Timer (mm)
[0082] Once the scanner has been asked to provide the PLC with information it will be asked to rescan to check the data collected based on this timer.
[0083] D. Max Height Variation Between Re-Scans (mm)
[0084] If the height difference between rescans exceeds this parameter a warning will be posted on the HMI. The operator can accept this new information or cancel it and proceed with the old information.
[0085] E. Change Vertical Setpoint if Rescan Variation Exceeds (mm).
[0086] If the variation between rescan heights is less than this parameter the unit pre-stage vertical setpoint will not be altered. If the variation is more than this parameter the vertical setpoint will be updated.
4. Data Collection
[0087] The scanner 100 is a laser radar based unit that, when requested, may sweep an arc of 100 degrees reporting back via serial communication the angle (on increments of 0.5 degrees) and the distance from the scanner to an object in front of the scanner if less than 80 m.
[0088] Software may collect this data to average the distance reading over five scans. The averaged data points may be converted from polar coordinates to rectangular coordinates. An equation (s) for this (these) data points may be differentiated to find the points of “rate of change”. The point with the greatest rate of change may be used a datum to reference other such points to determine the location of the required points on the hull with reference to the “zero” datum.
[0089] Referring to FIG. 2 the control logic is illustrated starting by selection of a prestige position 200 . The scanner initiates and acquires data in polar coordinates 202 , followed by conversion to rectangular coordinates referenced to the scanner 204 . The rectangular coordinates are differentiated 206 , to allow acquisition of gunwale, rubbing strake and tide level 208 . Then parameters A and B are calculated 210 . The process pauses for period C 212 and calculates parameter D 214 . The operator may choose to continue 216 , and parameter E is calculated 218 before continuing on the next interaction.
[0090] Where reference herein is made to the suction pad of the mooring robot engaging to the hull of the vessel, it is to be appreciated that this is the preferred location point of the suction pad. However other location points such as part of the superstructure or extensions from the hull may also present suitable surfaces for the suction pad to engage for the purposes of mooring the vessel.
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A profile scanner for locating a target zone on a profile of a vessel comprising an emitter adapted to progressively or instantaneously radiate towards the vessel; a receiver providing a signal indicative of radiation incident thereon; a controller or processor including stored instructions, for energising the emitter and receiving the signal, and adapted to determine the vertical location of the target zone relative to scanner.
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This application claims the benefit of U.S. provisional application Ser. No. 60/009,575, filed Jan. 3, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a drum-type imagesetter for producing an image on a flexible sheet of radiation-sensitive material.
2. Description of the Prior Art
The art of drum-type imagesetters comprises two types of apparatus.
First, the so-called internal drum recorders in which a flexible light-sensitive sheet is held against the inside surface of a stationary drum and is line-wise exposed by means of a rotating prism which deflects an axial laser beam at right angles onto the surface of the sheet. The mirror and its driving motor are mounted on a carriage which can travel axially through the drum thereby to cover the exposure width (i.e. the dimension parallel to the drum axis) of the apparatus.
Disadvantages of this type of apparatus are as follows:
the duty cycle is limited; a typical maximum of exposure period versus revolution period is approximately 70%; moreover, this ratio changes with the film sheet length (i.e. the dimension normal to the drum axis);
since the laser beam follows the centre line of the internal drum, one has to be careful with the generation of stray light; and
finally, sheet handling is difficult, in particular for relatively stiff sheets such as aluminium offset plates, and for small drum diameters.
A second class of apparatus are external drum recorders in which a light-sensitive sheet is fitted to the outside surface of a rotating drum, and the exposure occurs by a light source travelling along the outer periphery of the drum. These apparatus show the following disadvantages:
their rotational speed is limited (typically 2500 rpm) because of the high inertia of the drum, and
the duty cycle depends on the length of the light-sensitive sheets, in a way comparable with internal drum recorders.
SUMMARY OF THE INVENTION
Objects of the Invention
It is one object of the present invention to provide a light-weight imagesetter which allows the attainment of higher duty cycles than known apparatuses. In the best case, the duty cycle can amount up to 100% if leading and trailing edges of a sheet are in abutting relationship.
A further object of the invention is a rotating drum-type image recorder with a limited inertia so that the rotational speed can be higher than in conventional apparatus (typically up to 2500 rpm).
Still another object of the invention is an imagesetter the loading of which is more convenient than known apparatus. This is important for the loading of relatively stiff materials such as aluminium offset printing plates that can not readily be bent and made to conform to the circumference of the drum upon their loading, especially if the drum diameter is small.
Statement of the Invention
In accordance with the present invention a drum-type imagesetter for producing an image on a flexible sheet of radiation-sensitive material, which comprises
retaining means for retaining said sheet in a substantially cylindrical configuration, and
exposure means for image-wise exposing said curved sheet, is characterised thereby that said sheet retaining means comprises adjustment means allowing different drum diameters to be set for obtaining an optimum duty cycle for different sheet formats.
The sheet retaining means can be arranged to offer an almost uninterrupted supporting surface for a sheet, but preferably such supporting means is arranged for entering in supporting contact with local areas only of a sheet, thus forming so to say a virtual drum.
The absence of a rigid and uninterrupted cylindrical surface to back up the sheet to be image-wise exposed notably reduces the mass of the revolving parts of the apparatus, if the drum rotates and the exposure source is stationary. The resulting smaller inertia thus allows higher rotational speeds than usual to be used. Further a relatively light-weight overall construction can result.
According to one aspect of the invention, the sheet retaining means comprises means having radially inward surfaces for entering in physical contact with the outside surface, i.e. the convexly curved side, of the sheet, and are arranged for rotation about the axis of the drum thereby to force said sheet in tight engagement with said inward surfaces under the influence of centrifugal forces.
When film, paper or almost any other flexible sheet material is rolled into a cylindrical shape, the material achieves a greater rigidity and stability than when supported in flat or planar condition. This is the more so for aluminium lithographic printing plates which are still flexible but yet more rigid, i.e. having a greater rigidity than photosensitive film or paper. The cylindrical configuration of these plates is maintained also if the radially inward surfaces of the sheet retaining means are not continuous circular surfaces, but instead distinct surfaces equally angularly spaced thus rather forming a polygon for support of the plates.
The aspect of the invention described hereinbefore relates to internal drum exposure. However, an apparatus according to the invention is suited as well for external exposure and in such case the sheet retaining means will have radially outward surfaces for supporting the inward surface, viz. the concavely curved side of a sheet. In the latter case, additional means will be provided for keeping the sheet in contact with such supporting surfaces during rotation and at standstill of the drum.
The possibility afforded by the imagesetter according to the invention to use different drum diameters is important since it allows the circumference of the drum to match as close as possible the length of the sheet whereby a sheet can be made to cover up to at least 325 angular degrees of the drum corresponding with a duty cycle of 90%. Depending on the construction of the apparatus, a duty cycle theoretically up to 100% can be obtained.
Another interesting aspect of a variable drum diameter is that, in the case of internal drum exposure, the drum can be opened to a relatively large diameter whereby loading and/or unloading of a sheet can be easier. After loading of the sheet the drum diameter is reduced so that a higher duty cycle and a smaller inertia are obtained. This operation is in particular interesting for the loading of relatively stiff sheets such as aluminium offset printing plates which are less easy to manipulate. However, although the accent in the present description is on such plates, it should be understood that an imagesetter according to the present invention is as well suited for use with paper, plastic and other types of flexible supports for use in image-wise exposure.
The aspects described hereinbefore related to an imagesetter with rotating drum and stationary exposure means. It will be understood that the drum may as well be stationary and the exposure means rotating for the same advantages to be obtained, viz. an increased duty cycle and an easier loading.
The means for image-wise exposure of a sheet can be of the active or passive type. With active means we mean LED's (light-emitting diodes), conventional and high power lasers, and the like. With passive means we mean light valves capable of interrupting or modulating radiation from one or a plurality of sources, one or a plurality of small mirrors that can be deflected to control the amount of radiation reflected from a suitable light source onto the sheet, etc.
The term "radiation-sensitive" stands for light- as well as heat-sensitive recording material. A suitable material for heat-mode recording has been disclosed in EP 93 201 858.3.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described hereinafter by way of example with reference to the accompanying drawings, wherein:
FIGS. 1a, 1b and 1c show one embodiment of an adjustable imagesetter according the internal-drum type according to the invention,
FIGS. 2a to 2f show one embodiment of a method for loading a sheet in an imagesetter according to FIGS. 1a and 1b,
FIG. 3 shows an other embodiment of an adjustable imagesetter according to the invention for internal-drum exposure, provided with an elongate exposure head for the image-wise exposure, and
FIG. 4 shows the imagesetter according to FIG. 3, but provided with two separate exposure heads for carrying out the exposure.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1a to 1c, there is shown an embodiment of a virtual internal drum imagesetter having an adjustable diameter according to the invention.
Drum 41 is a cage-like construction formed by two axially spaced circular flanges 42, 43 rigidly interconnected by parallel bars 45. The flanges have inside hubs 46, 47 with angularly spaced radial bores 48 forming with corresponding bores in bars 45 slide bearings for the rotational bearing of screw-threaded radial shafts 49, 50. The inside ends of the shafts have conical pinions 51 engaging crown wheels 52, 53 rotatably journalled in corresponding hubs 46, 47. The crown wheels are also rotatably journalled on a stationary shaft 57 by means of roller bearings 54, 56. One shaft of each of series 49, 50 bears a gear wheel 58, 59, a timing belt 60 or the like coupling both gears to each other. Main shaft 57 is supported in the light-tight housing of the apparatus and one of flanges 42, 43 can be provided with a pulley, a gear or the like for coupling the drum to a suitable driving motor so that the drum can be rotated as indicated by arrow 61.
The apparatus comprises a number of sheet-supporting bars 62, twelve in the present example, the ends of which are in screw-threaded engagement with radial shafts 49, 50. Each bar 62 has a number of cross bars in the form of fingers 63 extending at a right angle on both sides thereof, the fingers of adjacent bars 62 being axially shifted, as shown for the upper and lower bars in FIG. 1b, so that they interengage each other. The purpose of the interengaging fingers is to define an uninterrupted peripheral guiding path for a sheet as it is tangentially loaded into the drum. The fingers can be straight as shown, but can also be curved, the radius of curvature of their inside surfaces being larger than that of the largest diameter of the drum.
The apparatus finally comprises a sheet feeding roller pair 64 comprising two rollers 65 and 67, as shown in FIGS. 1b and 1c. FIG. 1c which is a cross-sectional view along line 1c--1c of FIG. 1b. Rollers 65 and 67 have a crenelated profile, the larger diameter sections having a resilient covering 68 for driving engagement with the sheet surface. At one position there have been shown the interengaging fingers 63' and 63" of opposed bars 62. This construction will be further explained with reference to FIGS. 2a to 2f hereinafter.
Finally, the apparatus comprises an exposure head 70 which is mounted for translation on shaft 57 as indicated by arrow 71, and which is provided with focusing means for focusing, see the arrow 72, its radiation beam onto a sheet in the drum.
Exposure head 70 is moved by suitable driving means, and its electrical connections can be passed through shaft 57 for outside connection. The head can comprise a single radiation source or an elongated array of adjacent sources running parallel to the drum. In operation of the imagesetter, a sheet 73 within the drum, see FIG. 1a, is helically exposed as the drum rotates and the exposure head axially moves from one end to the other of the drum.
Rotation of the drum causes the sheet to be firmly applied against supporting fingers 63 by centrifugal forces and/or by stops engaging its leading and trailing edge, and as a consequence of its increased stiffness in a direction parallel to the drum axis, aluminium plate 73 assumes a cylindrical shape.
The duty cycle of the illustrated example is limited since, as shown, the sheet occupies approximately 225 angular degrees only of the drum. However, this imagesetter has a variable diameter, and by appropriate rotation of belt 60, e.g. through a small electric motor with reduction gear, radial shafts 49, 50 are rotated synchronously whereby bars 62 can be approached towards each other, as shown by arrows 75 in FIG. 1a. In that way a situation can be obtained in which the sheet covers at least 350 angular degrees of the drum.
A suitable method of loading of the apparatus is now described in detail with reference to FIGS. 2a to 2f.
Drum 41 being in an angular position as shown in FIG. 2a, feed roller pair 64 is rotated until the leading end of sheet 73 is gripped in the nip of the rollers. The roller pair 64 which is bodily displaceable as shown by arrow 76 in dashed line is next swung upwardly, see FIG. 4b, whereby the leading end of the sheet becomes located inside the drum. Fingers 63 do not interfere with the roller movement since the smaller sections of the rollers provide space for the fingers, see FIG. 1c.
Next, rollerpair 64 is driven to introduce the sheet almost completely in the drum, see FIG. 2c. Then drum 41 is slightly angularly rotated in backward direction, see FIG. 2d, whereby the trailing end of the sheet passes beyond stop 78 formed by a hook-like extension on each of fingers 63 at one end of the drum opening.
Next drum 41 is rotated forward into its start position, see FIG. 2e, so that rollerpair 64 can be withdrawn into its original position outside the drum. The diameter adjustment mechanism is now actuated, see the arrows 75 in FIG. 2f, whereby the drum diameter is reduced until the leading and trailing sheet edges become clamped between end stops 78, 79, being located at that moment on a diameter 88 drawn in broken lines. It will be understood that the focusing means of the exposure head has to be adjusted in accordance with the distance to the radiation sensitive sheet. Therefore it is interesting to use auto-focusing means controlled by any suitable feed back system which is responsive to the actual distance between the sheet and the exposure source.
FIG. 3 illustrates another embodiment of a drum imagesetter with adjustable diameter.
Drum 80 is in fact a cage formed by two axially spaced disc-like flanges 81, 82 interconnected by ribs 83. The flanges are rotatably journalled on the stationary shaft 100 of the drum by means of roller bearings 101, 102.
Both flanges have radial grooves 85, 86 guiding the ends of radially displaceable bars 87 having over nearly their complete length a slot 89. Arms 90 and 91 pivotally connected at one end at respective flanges 81 and 82, have their other end slideably connected to groove 89 of bars 87 by means of pins 92, 93. The axial position of the pins is controlled by arms 94, 95 pivotally connected to rings 96, 97 rotatable in a corresponding groove of adjustment sleeves 98, 99 threadably engaging hubs 104, 105 that make part of the corresponding flanges of the drum.
Adjustment of the radial position of bars 87, and thus of the inside diameter of the drum, is obtained by changing the axial position of rings 96, 97 by appropriate rotation of sleeves 98, 99 with respect to the hubs. The arms 94, 95 correspondingly alter the axial position of pins 92, 93 and in consequence the radial position of said pins, and thus of bars 87, is changed.
The exposure of a sheet inside the rotating virtual drum occurs in the present example by means of a multi-element exposure head 103. This head comprises a multiplicity of LED's with associated driving circuits and appropriate focussing means, e.g. in the form of a Selfoc (Tradename), for focusing the image of the LED's on the innerside surface of the light-sensitive sheet. A suitable embodiment of a LED head with staggered rows of LED's on abutting arrays is disclosed in U.S. Pat. No. 4,536,778 of the present assignee.
FIG. 4 shows a virtual drum imagesetter with variable diameter according to FIG. 3 wherein, however, two exposure heads 106, 107 that each either comprise a single radiation source, or an elongate array of a plurality of sources are provided.
Both exposure heads can either mechanically or electronically be coupled to work together, thereby to cover each half the exposure width of the apparatus. It is clear that three or more exposure heads can be provided working together to constitute a multi-channel writing system.
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Drum-type imagesetter for producing an image on a flexible sheet of radiation-sensitive material, which comprises retaining bars (62) for retaining a sheet in a substantially cylindrical configuration, and an exposure system (70) for image-wise exposing the curved sheet, the radial position of the sheet retaining bars (62) being controlled by adjustment screws (49, 50) allowing different drum diameters to be set.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/878,674 filed on Jun. 11, 2002. The disclosure of the above application is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to communication systems on board mobile platforms such as aircraft and, more particularly, to an on-board wireless local area network (WLAN) accessible by passengers' portable electronic devices such as laptop computers.
BACKGROUND OF THE INVENTION
[0003] Mobile network systems have traditionally been limited in bandwidth and link capacity, making it prohibitively expensive and/or unacceptably slow to distribute broadband data and video services to all passengers on a mobile platform such as an aircraft, boat or train. There is great interest in making such services available to users on mobile platforms. A system for supplying television and data services to mobile platforms is described in co-pending U.S. patent application Ser. No. 09/639,912, the entire disclosure of which is incorporated herein.
[0004] The system described in application Ser. No. 09/639,912 provides bi-directional data transfer via satellite communications link between a ground-based control segment and a mobile RF transceiver system carried on each mobile platform. Each user on each mobile platform is able to interface with an on-board server by using a laptop, personal digital assistant (PDA) seat-back-mounted computer/display or other computing device. Each user can independently request and obtain Internet access, company intranet access, stored video and audio programming and live television programming.
[0005] It would be desirable to provide passengers with wireless connections to network services available on mobile platforms such as aircraft. There are concerns, however, about the possibility of interference to aircraft systems from portable electronic devices (PEDs) that might be used by passengers to make wireless connections to an on-board network. Of particular concern is the possibility of PED interference during critical phases of flight, for example, during takeoff and landing. There also are concerns that such networks might expose passengers and flight crews to radiated RF fields exceeding recommended health and safety limits for RF exposure.
[0006] Generally there are two types of PEDs: (1) intentional transmitters, which must transmit a signal in order to accomplish their function (e.g. cell phones, two-way radios, pagers and remote-control devices), and (2) non-intentional transmitters, which do not need to transmit a signal to accomplish their function, but nevertheless emit some level of radiation (e.g. laptop computers, compact disk players, tape recorders and electronic hand-held games). The Federal Aviation Administration (FAA) has not issued certification regulations for PEDs. The FAA does, however, restrict the use of PEDs on commercial airlines. FAA advisory circular AC91.21-1 paragraph 6.a (7) states that, unless otherwise authorized, use of PEDs classified as intentional transmitters should be prohibited during aircraft operation. General Operating and Flight Rules, 14 CFR 91.21(b)(5) (“Portable Electronic Devices”) prohibits the operation of a PED on an aircraft, unless the aircraft operator has determined that the device will not cause interference with the navigation or communication systems on board the aircraft. Thus it is desirable to provide a wireless network that can be determined to be accessible by passenger-operated PEDs without causing such interference and thus could be authorized for on-board use. It also is desirable to provide an on-board wireless network that produces RF emission levels within recommended health and safety limits.
SUMMARY OF THE INVENTION
[0007] In one preferred form, the present invention provides a wireless local area network adapted for use by users traveling on a mobile platform such as an aircraft. The network includes a network server located on the mobile platform, and at least one network access point connected to the server and accessible wirelessly by at least one user portable electronic device over one of a plurality of non-overlapping network frequency channels. This wireless local area network can provide two-way communication, data and entertainment for aircraft passengers, cabin crews and flight crews. Such information may be obtained via e-mail, internet, company intranet access, and/or from data stored on board or off board the aircraft. The RF characteristics of this wireless network are specifically tailored to meet applicable standards for electromagnetic compatibility with aircraft systems and RF exposure levels for passengers and flight crews.
[0008] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0010] FIG. 1 is a view of a wireless LAN (“WLAN”) adapted for use in a mobile platform such as an aircraft;
[0011] FIG. 2 is a plan view of WLAN cells in an aircraft passenger cabin, shown from above the overhead area;
[0012] FIG. 3 is a graph of E-field strength of emissions versus transmitter-to-victim distance for a WLAN;
[0013] FIG. 4 is a view of a portion of a passenger cabin, shown from above the overhead area, in which more than one user PED is in use; and
[0014] FIG. 5 is a graph of margins of compliance with FCC OET Bulletin 65 for the effect of adjacent laptops on RF exposure versus distance from transmitter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. As described below, the present invention in one embodiment is directed to a wireless LAN (“WLAN”) for use in a mobile platform. The mobile platform could include an aircraft, cruise ship or any other mobile vehicle. Thus the reference to the mobile platform as an aircraft throughout the following description should not be construed as limiting the applicability of the WLAN 10 and/or the present invention to only aircraft.
[0016] A preferred embodiment of a wireless LAN for use in a mobile platform such as an aircraft is indicated generally by the reference numeral 10 in FIG. 1 . The WLAN 10 includes an Ethernet router/server 14 (hereinafter “server”) wired to a plurality of access points 18 via at least one switching device such as an Ethernet switch 22 . In the embodiment shown in FIG. 1 , the server 14 is connected to a transmit antenna, in this example, a transmit phased array antenna system 26 , and to a receive antenna, which in this example comprises a receive phased array antenna system 30 . The antenna systems 26 and 30 provide for two-way communication via satellite link between the WLAN 10 and a ground based network segment, as described in co-pending U.S. patent application Ser. No. 09 / 639 , 912 . The server 14 can interface with other systems, for example, with in-flight entertainment and/or telephone service systems. In another embodiment the WLAN 10 operates standalone in the mobile platform.
[0017] Each access point 18 has an antenna 34 located, for example, in the passenger cabin overhead. Each access point 18 is configured to transmit RF signals to, and receive RF signals from, one or more PEDs 38 carried on board by passengers. Such PEDs are fabricated for wireless use or have a wireless adapter antenna (not shown) and can include laptops, PDAs or the like. The access point antenna 34 may be, for example, an omni-directional or patch antenna. The number and location of access points 18 , and the number of PEDs 38 associated with an access point 18 , can vary as further described below.
[0018] An exemplary arrangement of access point antennas 34 relative to PEDs 38 is shown in FIG. 2 , which is a plan view of a portion 76 of an aircraft passenger cabin. Two access points 18 (not shown in FIG. 2 ) and associated antennas 34 are located in the overhead. Although an access point 18 could be located outside the cabin overhead, locating it close to its antenna 34 in the overhead reduces the length of a cable connection between them. Each access point 18 broadcasts over a cell 80 that includes eighteen seats 84 . Other cell sizes and numbers of associated seats can be used, as further described below. Factors influencing the sizes and numbers of cells 80 include seat width 92 , seat pitch 96 , distance 100 between antennas 34 , interior width 104 of the cabin, and the width 108 of each of the rows of seats 84 .
[0019] The WLAN 10 operates in the 2.40 to 2.483 GHz ISM band, which is designated for unlicensed commercial or public use. Other licensed or unlicensed bands above 2.4 GHz, for example, the ISM 5.725 to 5.875 GHz band, could also be used. The WLAN 10 is configured in conformance with the IEEE 802.11b (High Rate) standard. The invention is not so limited, and other bands, standards, and protocols can be used. Each access point 18 communicates with the server 14 through the Ethernet switch 22 at full available bandwidth. The WLAN 10 utilizes Direct Sequence Spread Spectrum (DSSS) transmission between each access point 18 and its associated user PEDs 38 . That is, the spectrum is divided into three non-overlapping frequency channels of approximately 22 MHz each. It is contemplated that other spread-spectrum modulation methods also could be used.
[0020] Each access point 18 is configured to communicate with PEDs 38 over one of the three channels. For example, as shown in FIG. 1 , three access points 18 communicate using channels 1 , 6 and 11 respectively. Adjacent access points 18 broadcast over different channels. For example, referring to FIG. 2 , a user sitting in a cell 80 in which the associated access point 18 broadcasts over channel 1 could communicate with the WLAN 10 via channel 1 . Another passenger sitting in an adjacent cell 80 would communicate with the WLAN 10 over channel 6 or channel 11 .
[0021] Where the number of access points 18 exceeds three, each channel can be re-assigned to another access point 18 that is not adjacent to an access point to which the channel is already assigned. For example, seven access points 18 located sequentially along the aircraft aisle overhead could use channels 1 , 6 , 11 , 1 , 6 , 11 and 1 respectively. Thus use of each of the three channels can be distributed spatially over the aggregate of cells 80 , for example, to users distributed over the entire passenger cabin. Of course, the channels can be distributed over a plurality of cells in many different ways. Additionally, a connected user PED 38 can roam, e.g. as supported by the IEEE 802.11b protocol. That is, a WLAN 10 connection established with a user PED 38 in one cell 80 over one channel can be maintained over another channel if the user PED 38 roams to other cells. For example, a user carrying a PED 38 can walk, from one cell 80 in which the PED is connected to the WLAN 10 via channel 1 , into an adjacent cell 80 in which, for example, channel 6 is being used, and maintain the connection to the WLAN 10 .
[0022] Communication between the PEDs 38 and the access points 18 is half-duplex. That is, in each frequency channel, at any one time either the access point 18 or one user PED 38 can transmit. PEDs communicate via CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance). That is, a PED 38 checks for a quiet channel before transmitting to its associated access point 18 . If the channel is busy, the PED waits a random amount of time and then retransmits. Several PEDs 38 could transmit simultaneously when contending for channel use. If a collision of their signals is detected, each of the transmitting PEDs “backs of” and waits a random time period before retransmitting. Eventually one PED gains control of the channel and transmits.
[0023] The WLAN 10 is configured such that only access points 18 and PEDs 38 that meet applicable interference, health and safety requirements are allowed to operate within the network. PEDs that do not comply with such standards are excluded from connecting to the WLAN 10 . More specifically, and for example, according to IEEE 802.11b protocol, each type of PED 38 that has passed testing for compliance with applicable interference, health and safety standards is identified in the MAC (Media Access Control) layer of the WLAN 10 . Thus it can be determined at each access point 18 whether a remote PED 38 has been predetermined to be suitable for connection to the WLAN 10 . If the PED is one that has been approved for connection, it is allowed to connect to the network; if not, the PED request for network access is ignored.
[0024] Configuring a WLAN for use in aircraft entails consideration of a variety of factors, including those related, for example, to aircraft and passenger safety. Not all of such factors, however, are unique to aircraft. Thus many of the considerations for configuring an aircraft WLAN also pertain to configuring a WLAN for use in other types of mobile platforms. Embodiments of a mobile WLAN as described above can be configured in accordance with the following assumptions, determinations and considerations.
[0025] Distance Assumptions and Far Field Calculations
[0026] Emissions by 802.11b wireless LANs can be treated as a far field problem. The wavelength, λ, at 2.4 GHz is 0.125 meters. The far field limit is approximated by 2*d 2 /λ where “d” is the largest dimension of the transmitting antenna. For a typical omni-directional or patch antenna utilized at a wireless access point mounted, for example, in the overhead in an aircraft passenger cabin, the largest dimension is assumed to be approximately 9 inches or 0.23 meters. The far field limit for such an antenna 34 , then, is approximately 0.85 meters.
[0027] A typical user PED 38 PCMCIA adapter antenna is assumed to have a largest dimension of 2 inches or 0.05 meters. The far field limit for such an antenna, then, is approximately 0.04 meters. Based on the foregoing assumptions and determinations, all WLAN 10 emissions more than one meter from an access point antenna 34 or more than four centimeters from a user PED 38 antenna can be treated as being in the far field.
[0028] Non-coaxial aircraft system cables can be lossy at the frequencies contemplated for use in the airborne WLAN 10 . Therefore, possible effects of WLAN-radiated field levels at line replaceable units (LRUs) of an aircraft system are considered. An access point antenna 34 transmitting to users in an aircraft passenger compartment would be prevented by its ground plane (not shown) from radiating at significant levels into the overhead compartment. Access point antenna 34 emissions, then, are investigated primarily for their effect on equipment in avionics bays under the floor or in the sidewalls of the aircraft. The user PED 38 antennas could radiate into both the overhead and underfloor areas of the aircraft. System LRUs can be installed in equipment bays and/or in the overhead throughout the aircraft. Therefore the minimum distance from an operating access point antenna 34 or a user PED 38 adapter to an airborne system LRU is assumed to be one meter.
[0029] Field Strength Levels
[0030] The following methodology is used to evaluate field strength levels for both aircraft system RF susceptibility and for RF exposure compliance. For the following analysis of field strength levels, it is assumed that a transmit antenna on either an access point or user adapter has a maximum gain value of 2.2 dBi (numerical value 1.66), and that transmit cable losses are zero dB. The far field radiated power density is given by:
P d =( P t *G )/(4*π* D 2 ) (1)
where “P t ” is transmitter power at antenna input in watts, “G” is numerical gain of the transmit antenna relative to an isotropic source, and “D” is distance from center of transmit antenna to measuring point in meters.
[0031] The E-field in free space is given by:
E ( v/m )= SQRT ( P d *377), or (2)
E ( dBuv/m )=20 LOG 10 ( E* 10 6 ) (3)
where “E”
[0032] Where “E” is the E-field strength in volts per meter and “dBuv/m” is field strength in dB above 1 microvolt per meter. Referring to FIG. 3 , test data indicate that, for a single transmitter, transmitted power levels of both 1 and 3 milliwatts with a nominal unity gain (0 dBi) transmit antenna, the field strength is at or below 110 dBuv/m (0.3 volts per meter) for all distances greater than one meter. For multiple transmitters operating simultaneously using 802.11b protocol, field strength levels are analyzed as further described below.
[0033] Maximum Permissible Exposure (MPE) Levels
[0034] A 802.11b network operates in the 2.4 to 2.483 GHz ISM band. The IEEE C.95.1-1999 standard for human exposure to RF electromagnetic fields specifies a maximum permissible whole body exposure (MPE) level for this frequency region in an uncontrolled environment of f/1500 mw/cm2 averaged over 30 minutes, where f is frequency expressed in MHz. The worst case or minimum value is at the lower end of the frequency band where MPE=2400/1500=1.6 mw/cm2 or 16 w/m2. The FCC requirement as specified in OET Bulletin 65 for this frequency range is 1.0 mw/cm2 or 10 w/m2 averaged over 30 minutes. Although the European CENELEC ES59005 maximum allowable RF exposure levels are less stringent than the FCC limits, the more conservative FCC requirements for compliance are used herein.
[0035] Maximum 802.11b Radiated Field Strengths
[0036] It is assumed that over any 30-minute interval the separation distance from an individual to an access point antenna 34 in the overhead is 1.0 meters. Table 1 below describes 2.4 GHz WLAN radiated emissions at transmit powers from 1 to 100 milliwatts and at a transmitter-to-victim distance of 1 meter.
TABLE 1 2.4 GHz WLAN Radiated Emissions Victim to Transmitter Distance = 1 m lambda = 0.125 m Assume Tx antenna gain (dBi) = 2.2 = numeric Eff Area = 0.001875 m{circumflex over ( )}2 1.659587 short dipole Transmit Tx Power Tx Field Tx Field Received Power Density Strength Strength Received Power (mw) w/m{circumflex over ( )}2 v/m dBuv/m Power w dBm 1 0.000132066 0.223134 106.9713 2.48E−07 −36.06209 3 0.000396197 0.386479 111.7425 7.43E−07 −31.29087 5 0.000660329 0.498943 113.961 1.24E−06 −29.07239 10 0.001320657 0.705612 116.9713 2.48E−06 −26.06209 20 0.002641315 0.997886 119.9816 4.95E−06 −23.05179 30 0.003961972 1.222155 121.7425 7.43E−06 −21.29087 50 0.006603286 1.577796 123.961 1.24E−05 −19.07239 100 0.013206573 2.23134 126.9713 2.48E−05 −16.06209
[0037] Referring to Table 1, test data indicate that an 802.11b system radiating at 3 mw maximum output power will generate a radiated power density of 4×10-4 w/m2 at the distance of 1 meter from the access point antenna 34 . This power density is 4.0×10-5 times the maximum allowed FCC level, which is equal to a margin of 44 dB.
[0038] It is possible for tall individuals to be within 0.25 meters of an overhead access point antenna 34 in a single-aisle aircraft or for a user to be within 0.05 meters of his/her PED 38 antenna. Table 2 below describes 2.4 GHz WLAN radiated emissions at transmit powers from 1 to 100 milliwatts and at a transmitter-to-victim distance of 0.05 meter.
TABLE 2 2.4 GHz WLAN Radiated Emissions Victim to Transmitter Distance = 0.05 m lambda = 0.125 m Assume Tx antenna gain (dBi) = 2.2 = numeric Eff Area = 0.001875 m{circumflex over ( )}2 1.659587 short dipole Trans- mit Tx Power Tx Field Tx Field Received Power Density Strength Strength Received Power (mw) w/m{circumflex over ( )}2 v/m dBuv/m Power w dBm 1 0.052826292 4.46268 132.9919 9.9E−05 −10.0415 3 0.158478876 7.729588 137.7631 0.000297 −5.27027 5 0.26413146 9.978856 139.9816 0.000495 −3.05179 10 0.52826292 14.11223 142.9919 0.00099 −0.04149 20 1.056525839 19.95771 146.0022 0.001981 2.968814 30 1.584788759 24.4431 147.7631 0.002971 4.729727 50 2.641314598 31.55591 149.9816 0.004952 6.948214 100 5.282629196 44.6268 152.9919 0.009905 9.958514
[0039] Table 3 below describes margins of compliance with FCC OET Bulletin 65 for worst-case exposure with access points separated by 3 meters and with multiple transmitters.
TABLE 3 Worst Case Exposure with Multiple Transmitters Compliance Margins for FCC OET Bulletin 65 Reqmt Seat spacing (row) = 0.8 m in = 31.496 Self Dist = 0.05 m Seat spacing (side) = 0.5 m in = 19.685 FCC Rqmt 10 w/m 2 Access Pt Spacing = 3 m Assume Tx antenna gain (dBi) = 2.2 = numeric 1.659587 Single Emitter Tx Pwr = 3 Pwr Dens Distance m w/m 2 0.75 0.000704 0.7 0.000809 0.6 0.001101 0.5 0.001585 0.4 0.002476 0.3 0.004402 0.25 0.006339 0.2 0.009905 0.1 0.03962 0.05 0.158479 Two & Four Adjacent Emitters + Own @ 0.05 meter Tx Pwr = 3 mw Four + own Two + own Single Dist-TX#1 Two + own Margin Margin Four + own Margin m Dist-TX#2 m w/m 2 dB dB w/m 2 dB 0.25 0.75 0.165522 17.81143 41.52211 0.166931 17.77463 0.3 0.7 0.16369 17.85979 40.92285 0.165098 17.82257 0.4 0.6 0.162056 17.90336 39.58391 0.163464 17.86577 0.5 0.5 0.161648 17.91428 38.00029 0.163057 17.8766 0.6 0.4 0.162056 17.90336 36.06209 0.163464 17.86577 0.7 0.3 0.16369 17.85979 33.56331 0.165098 17.82257 0.75 0.25 0.165522 17.81143 31.97969 0.166931 17.77463 0.8 0.2 30.04149 0.9 0.1 24.02089 0.95 0.05 18.00029 Exposure from Two Adjacent Access Pts Tx Pwr = 3 mw PwrDens Margin Dist-TX#1 m Dist-TX#2 m w/m 2 dB 0.25 2.75 0.006392 31.94394 0.3 2.7 0.004457 33.51002 0.4 2.6 0.002535 35.96049 0.5 2.5 0.001648 37.82995 0.6 2.4 0.001169 39.32062 0.7 2.3 0.000883 40.53813 0.8 2.2 0.000701 41.54333 0.9 2.1 0.000579 42.37342 1 2 0.000495 43.05179 1.1 1.9 0.000437 43.59334 1.2 1.8 0.000397 44.0075 1.3 1.7 0.000372 44.30008 1.4 1.6 0.000357 44.47446 1.5 1.5 0.000352 44.53241
[0040] Referring to Tables 2 and 3, test data indicate that an 802.11b system radiating at 3 mw maximum output power will generate a radiated power density of 6.3×10-3 w/m2 at the worst-case minimum distance of 0.25 meters from the access point antenna 34 and 1.6×10-1 w/m2 at the worst-case minimum distance of 0.05 meters from the user PED 38 antenna. For the access point antenna 34 , this power density is 6.3×10-4 of the maximum allowed FCC level, which is equal to a margin of 32 dB. For the user PED 38 antenna, this is 1.6×10-2 of the maximum allowed FCC level, which is equal to a margin of 18 dB.
[0041] Contribution from Multiple WLAN Sources
[0042] The contribution of multiple WLAN RF emission sources simultaneously transmitting is addressed next. Referring to FIG. 2 , the width 92 of each seat 84 is assumed to be 0.5 meters. The seat pitch 96 is assumed to be 0.8 meters (32 inches) and the distance 100 between access point antennas 34 is assumed to be a minimum of 2.5 to 3 meters. Thus it is assumed that the worst-case RF levels are generated by multiple users transmitting via PEDs 38 while sitting in the seats 84 or otherwise closely spaced in the cell areas 80 . It is assumed that the user PEDs 38 transmit simultaneously when they contend for the RF medium as previously described. Such simultaneous transmissions occur only for short periods of time (before one PED is granted access to transmit), compared to the 30-minute exposure time described above in connection with the FCC maximum allowed level of power density. The possibility nevertheless is considered, however, that such transmissions might generate RF signal levels that might interfere with airframe systems. It also is assumed that these asynchronous sources are in phase and that their transmitted signals will add constructively, even though this is unlikely.
[0043] A layout of a plurality of PEDs 38 in adjacent seats 84 is shown in FIG. 4 . The predominant source of EMI is likely to be a user's own laptop 38 antenna, which was assumed above to be at the worst-case distance of 0.05 meters from the user. FIG. 5 shows margins of compliance to FCC emission requirements for a single laptop and for a laptop adjacent to other laptops. At the assumed seat width of 0.5 meters, the effect of one adjacent emissions source diminishes as the user approaches (e.g. leans toward) the other source. The seat pitch is assumed to be 0.8 meters (32 inches). Therefore the contributions from sources in seat rows in front of or behind the subject will not significantly affect the margin of compliance. As shown in Table 3, including two more sources at 0.75 meters (directly in front and in back of the subject laptop and transmitting at 3 mw) to the two sources in the same seat group plus the subject's laptop will only change the margin for RF exposure compliance from 17.81 to 17.77 dB.
[0044] Radiated Cell Dimensions
[0045] Cell size is determined based on the contemplated power level for the WLAN, the aggregate bandwidth contemplated to be available, and the number of users contemplated to share the bandwidth. For example, in the embodiment shown in FIG. 2 , a cell population of 3 rows includes 18 seats per access point. Such could be the case for a narrow body aircraft, e.g. a Boeing 737 or 757. A cell population of three rows on a wide body, e.g. a Boeing 767 or 200, could include 21 seats. A worst-case demand for bandwidth is likely to be for users requesting streaming video services. While systems using 802.11b protocol have been demonstrated to provide up to 8 Mbps per access point, a bandwidth of 6 Mbps is assumed to be achievable on a repeatable basis using standard hardware components. Thus it is assumed that a maximum aggregate bandwidth of 6 Mbps is available per access point 18 using short transmission preambles, and that typically 30 percent, i.e. 6 or 7 user PEDs 38 , in a cell 80 are active and sharing the 6 Mbps bandwidth. Less bandwidth-demanding services such as e-mail or Internet access can support more users per access point 18 . It is contemplated that power radiated by components of the WLAN 10 is kept in the 1- to 5-mw range in order to meet interference, health and safety requirements.
[0046] Received Signal Strength
[0047] Table 4 below describes 2.4 GHz WLAN radiated emissions at transmit powers from 1 to 100 milliwatts and at a transmitter-to-victim distance of 3 meters. Assuming a maximum distance of 3 meters between an access point and its cell boundary, as shown in Table 4, a user PED 38 at the maximum distance from an access point antenna 34 broadcasting at 1 milliwatt receives a signal in the range of −45 to −50 dBm. This signal exceeds the 802.11b-specified value of −76 dBm required to support 11 Mbps communication. Such margin protects against signal fading due to mulltipath within the aircraft cabin.
TABLE 4 2.4 GHz WLAN Radiated Emissions Victim to Transmitter Distance = 3 m lambda = 0.125 m Assume Tx antenna gain (dBi) = 2.2 = numeric Eff Area = 0.001875 m{circumflex over ( )}2 1.659587 short dipole Trans- mit Tx Power Tx Field Tx Field Received Power Density Strength Strength Received Power (mw) w/m{circumflex over ( )}2 v/m dBuv/m Power w dBm 1 1.4674E−05 0.074378 97.42889 2.75E−08 −45.60451 3 4.40219E−05 0.128826 102.2001 8.25E−08 −40.8333 5 7.33698E−05 0.166314 104.4186 1.38E−07 −38.61481 10 0.00014674 0.235204 107.4289 2.75E−07 −35.60451 20 0.000293479 0.332629 110.4392 5.5E−07 −32.59421 30 0.000440219 0.407385 112.2001 8.25E−07 −30.8333 50 0.000733698 0.525932 114.4186 1.38E−06 −28.61481 100 0.001467397 0.74378 117.4289 2.75E−06 −25.60451
[0048] RF Susceptibility Test Levels For Aircraft Equipment
[0049] Aircraft systems have been qualified to varying RF susceptibility test levels and frequency ranges. Those systems that have been determined to be flight-critical and essential are required to demonstrate immunity to the effects of High Intensity Radiated Fields (HIRF) and have been tested to field strengths that are many orders of magnitude above the RF field strength generated by an 802.11b WLAN system. Other systems qualified to levels below the HIRF levels also have demonstrated RF immunity in the 2.4 to 2.483 GHz frequency range. For any aircraft system for which there is no radiated susceptibility test data in the 802.11b operating band of 2.4 to 2.483 GHz, it is proposed that aircraft level susceptibility testing be performed to demonstrate that there will be no interference from the worst case operation of an 802.11b wireless LAN configured in accordance with the embodiments described herein.
[0050] The above-described WLAN 10 includes multiple intentional RF transmitters that operate at very low levels of RF field strength. These low levels provide significant margins of compliance for both electromagnetic interference and RF exposure limit regulations for operators, airframe manufacturers, and the traveling public. This makes it possible to safely operate the above-described WLAN 10 on board commercial aircraft in flight.
[0051] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A wireless local area network adapted for use by users traveling on a mobile platform such as an aircraft. The network includes a network server located on the mobile platform, and at least one network access point connected to the server and accessible wirelessly by at least one user portable electronic device over one of a plurality of non-overlapping network frequency channels. The RF characteristics of this wireless network are specifically tailored to meet applicable standards for electromagnetic compatibility with aircraft systems and RF exposure levels for passengers and flight crews.
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BACKGROUND
Longitudinal members, such as spinal rods, are often used in the surgical treatment of spinal disorders such as degenerative disc disease, disc herniations, scoliosis or other curvature abnormalities, and fractures. Different types of surgical treatments are used. In some cases, spinal fusion is indicated to inhibit relative motion between vertebral bodies. In other cases, dynamic implants are used to preserve motion between vertebral bodies. For either type of surgical treatment, longitudinal members may be attached to the exterior of two or more vertebrae, whether it is at a posterior, anterior, or lateral side of the vertebrae. In other embodiments, longitudinal members are attached to the vertebrae without the use of dynamic implants or spinal fusion.
Longitudinal members may provide a stable, rigid column that encourages bones to fuse after spinal-fusion surgery. Further, the longitudinal members may redirect stresses over a wider area away from a damaged or defective region. Also, rigid longitudinal members may restore the spine to its proper alignment. In some cases, flexible longitudinal members may be appropriate. Flexible longitudinal members may provide other advantages, such as increasing loading on interbody constructs, decreasing stress transfer to adjacent vertebral elements while bone-graft healing takes place, and generally balancing strength with flexibility.
Conventionally, longitudinal members are secured to vertebral members using rigid clamping devices. These clamping devices may be multi-axial in the sense that they are adjustable prior to securing. However, once secured, the clamping devices are locked in place. A surgeon may wish to implant a flexible rod system and have more freedom to control pivot points or the nature of the pivoting motion. At present, a surgeon might only have a choice between rigid and flexible longitudinal members, which may not necessarily provide the desired degree of flexibility.
SUMMARY
Illustrative embodiments disclosed herein are directed to a pivoting connector that couples a vertebral member to a longitudinal member. An anchor is pivotally attaching to a body by positioning a head of the anchor within a cavity in the body. The body may also include a channel that is also positioned within the body and axially aligned with the cavity. The channel may be disposed on an opposite side of the cavity. An intermediate section may separate the channel and cavity. A longitudinal member may be placed within the channel and a retainer applies a force to maintain the longitudinal rod within the channel. The retaining force applied to the longitudinal member may be isolated from the anchor. The cavity may be adjustable between a plurality of sizes that apply different resistances to pivoting movement of the anchor relative to the body. The adjustment may be performed before or during a surgical procedure. According to one or more embodiment, inserting different components into the cavity may achieve the varying rotational resistances. According to one or more embodiments, rotating a threaded element into or onto the body may create more or less rotational interference or rotational resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are perspective views of a pivoting head assembly according to one or more embodiments comprising a longitudinal member attached to the spine;
FIGS. 2A and 2B are perspective views of a pivoting head coupled to an anchor member according to one embodiment;
FIG. 3 is a side section view of a pivoting head coupled to an anchor member and securing a longitudinal member according to one embodiment;
FIG. 4 is a perspective view of an anchor member for use with a pivoting head according to one embodiment;
FIGS. 5A-C are top section views of a pivoting head with an anchor member and wear member inserted therein according to different embodiments;
FIG. 6 is a perspective view of a wear member for use with a pivoting head according to one embodiment;
FIG. 7 is a side view, including a partial section view, of an assembled anchor member and wear member for use with a pivoting head according to one embodiment;
FIG. 8 is a side section view of a pivoting head with an anchor member and wear member inserted therein according to one embodiment;
FIG. 9 is a side section view of an assembled pivoting head with an anchor member and wear member constrained therein according to one embodiment;
FIG. 10 is a detailed section view of the bottom region of a pivoting head according to one embodiment;
FIG. 11 is a side section view of a pivoting head and various wear members that may be used with the pivoting head according to one embodiment;
FIG. 12 is a side section view of an assembled pivoting head with an anchor member and wear member constrained therein according to one embodiment;
FIG. 13 is a detailed section view of the bottom region of a pivoting head according to one embodiment;
FIG. 14 is a detailed section view of the bottom region of a pivoting head according to one embodiment;
FIG. 15 is a detailed section view of an interference snap ring that may be used with the pivoting head according to one embodiment;
FIG. 16 is a perspective view of a pivoting head coupled to an anchor member according to one embodiment;
FIG. 17 is a side section view of an assembled pivoting head with an anchor member and wear member constrained therein according to one embodiment;
FIG. 18 is a side section view of an assembled pivoting head with an anchor member and wear member constrained therein according to one embodiment;
FIG. 19 is a perspective view of a wear member for use with a pivoting head according to one embodiment;
FIG. 20 is a side section view of an assembled pivoting head with an anchor member and wear member constrained therein according to one embodiment; and
FIG. 21 is a side section view of an assembled pivoting head with an anchor member and wear member constrained therein according to one embodiment.
DETAILED DESCRIPTION
The various embodiments disclosed herein are directed to pivoting mechanisms and methods for securing longitudinal members in a spinal implant. Various types of longitudinal members are contemplated, including spinal rods that may be secured between multiple vertebral bodies. FIGS. 1A and 1B show another type of longitudinal member 15 that is secured between the sacrum S and a vertebral member V (i.e., L5). In one embodiment, the longitudinal member 15 is a flexible member, such as a resin or polymer compound. Some flexible non-metallic longitudinal members 15 are constructed from materials such as PEEK and UHMWPE. Other types of flexible longitudinal members 15 may comprise braided metallic structures. In one embodiment, the longitudinal member 15 is rigid or semi-rigid and may be constructed from metals, including for example stainless steels, cobalt-chrome, titanium, and shape memory alloys. Further, the longitudinal member 15 may be straight, curved, or comprise one or more curved portions along its length.
In FIGS. 1A and 1B , the longitudinal member 15 is secured to the vertebral member V with one embodiment of a pivoting head 10 in accordance with the teachings provided herein. In the embodiment shown, the longitudinal member 15 is secured to a saddle 16 within the pivoting head 10 with a securing member 12 . The securing member 12 shown in FIGS. 1A and 1B features a snap-off driving member 14 . The driving member 14 is integrally formed with the securing member 12 and allows a surgeon to drive the securing member 12 into contact with the longitudinal member 15 to achieve a certain installation torque. Above that torque, the driving member 14 will snap off, separating from the securing member 12 . In this manner, the securing member 12 may provide the desired clamping force to secure the longitudinal member 15 .
FIG. 1A shows a first orientation for the pivoting head 10 identified by the centerline labeled X. By contrast, FIG. 1B shows a second position representing a different spatial relationship between the sacrum S and the vertebra V. As compared to FIG. 1A , the vertebra V in FIG. 1B exhibits some amount of angular and torsional displacement relative to the sacrum S. Consequently, the pivoting head 10 is illustrated in a second orientation identified by the centerline labeled Y. The pivoting head 10 may provide some or all of this rotation. The illustrations provided in FIGS. 1A and 1B show the pivoting head 10 as part of a spinal implant that is coupled between a vertebral body V and a sacrum S. It should be understood that the pivoting head 10 may be used in constructs that are coupled to vertebral bodies V alone. Further, a vertebral implant may be construed to mean implants that are coupled to any or all portions of a spine, including the sacrum, vertebral bodies, and the skull.
FIGS. 2A and 2B illustrate perspective views of the illustrative embodiment of the pivoting head 10 coupled to an anchor member 18 . A head 32 of the anchor member 18 is pivotally coupled to a base portion 34 of the pivoting head 10 . In one embodiment, the anchor member 18 comprises threads for insertion into a vertebral member V as shown in FIGS. 1A and 1B . In one embodiment, the anchor member 18 is a pedicle screw. The exemplary saddle 16 is comprised of opposed upright portions forming a U-shaped channel within which a longitudinal member 15 is placed. A seating surface 24 forms the bottom of the U-shaped channel. In one embodiment, the seating surface 24 is curved to substantially match the radius of a longitudinal member 15 that is positioned within the saddle 16 . An aperture 26 within the seating surface provides access to a driving feature used to insert the anchor member 18 into a vertebral member V.
In FIG. 2A , the pivoting head 10 is shown substantially aligned with the anchor member 18 along the centerline labeled X. In FIG. 2B , the anchor member 18 is shown pivoted relative to the pivoting head 10 . That is, the pivoting head 10 is shown still aligned with the centerline labeled X while the anchor member 18 is shown aligned with the centerline labeled Y. The pivoted displacement of the pivoting head 10 relative to the anchor member 18 achieved in FIG. 2B is provided by an articulation mechanism that is more clearly visible in the section view provided in FIG. 3 .
FIG. 3 shows a section view of the pivoting head 10 holding a different type of longitudinal member 28 . In this embodiment, the longitudinal member 28 is a spinal rod. The spinal rod 28 is secured within the saddle 16 with a securing member 12 . In the embodiment shown, the securing member 12 is an externally threaded set screw, though other types of securing members such as externally threaded caps and nuts may be used. In the embodiment shown, an articulation mechanism 40 is disposed below the saddle 16 and generally aligned with the central axis X. The articulation mechanism 40 comprises an anchor head 32 of the anchor member 18 that is pivotally coupled to a wear member 30 within the base portion 34 of the pivoting head 10 . Since the anchor head 32 is configured to pivot within the wear member 30 , the wear member 30 and the outer surface of the anchor head 32 may be constructed of a wear resistance material. Some suitable examples may include hardened metals, titanium carbide, cobalt chrome, polymers, and ceramics.
In other embodiments, a wear resistant layer may be coated onto the anchor head 32 and the wear member 30 . In one embodiment, the wear member 30 may be integrally formed into or form a part of the base portion 34 . In one embodiment, the wear member 30 may be bonded to the base portion 34 using a biocompatible adhesive such as PMMA or other known adhesives. In these alternative embodiments, the part of the base portion 34 in contact with the anchor head 32 may be coated with a wear resistant layer. Coating processes that include, for example, vapor deposition, dip coating, diffusion bonding, and electron beam welding may be used to coat the above indicated materials onto a similar or dissimilar substrate. Diffusion bonding is a solid-state joining process capable of joining a wide range of metal and ceramic combinations. The process may be applied over a variety of durations, applied pressure, bonding temperature, and method of heat application. The bonding is typically formed in the solid phase and may be carried out in vacuum or a protective atmosphere, with heat being applied by radiant, induction, direct or indirect resistance heating. Electron beam welding is a fusion welding process in which a beam of high-velocity electrons is applied to the materials being joined. The workpieces melt as the kinetic energy of the electrons is transformed into heat upon impact. Pressure is not necessarily applied, though the welding is often done in a vacuum to prevent the dispersion of the electron beam.
The articulation mechanism 40 is spatially and functionally isolated from the clamping forces that are applied between the securing member 12 , the rod 28 , and the seating surface 24 (see FIGS. 2A , 2 B). That is, since the compression forces applied by the securing member 12 are not transmitted to the articulation mechanism 40 , the anchor member 18 rotates about the central axis X under the influence of the sliding resistance provided by the various embodiments disclosed herein. In this manner, the articulation mechanism 40 is not only spatially isolated from the securing member 12 , but also physically isolated from the forces provided by the securing member 12 .
FIG. 4 shows a perspective view of the anchor head 32 of the exemplary anchor member 18 . The anchor head 32 includes a driving feature 42 that allows a surgeon to attach the anchor member 18 to a vertebra V. In the embodiment shown, a hex recess driving feature 42 is shown. Other types of driving features 42 may be appropriate, including for example, slotted, star, Torx, and cross-shaped features. The driving feature 42 may be accessed through the aperture 26 shown in FIGS. 2A , 2 B, and 3 .
In the embodiment illustrated in FIG. 4 , the anchor head 32 is substantially spherical to allow multi-axial pivoting of the anchor member 18 relative to the pivoting head 10 . In other embodiments, the anchor head 32 has other shapes to allow motion in fewer directions. For instance, a disc-shaped anchor head 32 may provide motion within a desired plane. FIGS. 5A , 5 B, and 5 C illustrate some of these alternative embodiments. Specifically, FIGS. 5A-5C are top section views according to the section line X-X shown in FIG. 3 . FIG. 5A shows one embodiment where the anchor head 32 and wear member 30 are substantially spherical as previously described. With this configuration, the pivoting head 10 may pivot about a plurality of axes, including axes A, B, C, and D as shown in FIG. 5A . FIG. 5B shows an alternative embodiment where the anchor head 132 and wear member 130 are substantially disc-shaped. As disclosed above, this configuration may allow pivoting motion about axis B, but not other axes, including axis A. FIG. 5C depicts another embodiment that is characterized by at least two different spherical radii R 1 , R 2 . This configuration may provide a different resistance to rotation about axes A and B. A somewhat pronounced difference in radii R 1 , R 2 is shown in FIG. 5C , though in practice, a fairly small difference may produce the desired result.
FIG. 6 shows a perspective view of a wear member 30 according to one embodiment. As depicted, the wear member 30 is cylindrically shaped and includes an outer surface 44 and an inner surface 46 extending between a top surface 50 and a bottom surface 52 . Generally, the inner surface 46 is constructed to match the shape of the anchor head 32 of the threaded anchor member 18 . The outer surface 44 may be configured as desired to fit within the base portion 34 of the pivoting head 10 as shown in FIG. 3 . In one embodiment, the outer surface 44 is substantially cylindrical. The exemplary wear member 30 also includes a gap 48 . The gap 48 in the present embodiment may be used to spread open the wear member 30 by an amount sufficient to slip the wear member 30 over the anchor head 32 of the anchor member 18 .
The wear member 30 is shown installed on the anchor head 32 in FIG. 7 . FIG. 7 also shows relevant dimensions of the wear member 30 and the anchor head 32 . Dimension L represents a width of the anchor head 32 at its widest point. The width may comprise a diameter, a spherical diameter, or other linear dimension. Dimensions M and N respectively represent an interior width at the top 50 and bottom 52 of the wear member 30 . Notably, dimension L is larger than both M and N. Thus, the gap 48 allows the anchor head 32 to fit within the wear member 30 as shown in FIG. 7 .
FIG. 8 shows the assembled wear member 30 and anchor member 18 inserted into the base portion 34 of the pivoting head 10 . The anchor member 18 and wear member 30 are retained within the base portion 34 by deforming the lower lip 56 in the direction of the arrow labeled F. The deforming step may be performed using a variety of techniques, including but not limited to mechanical pressing, swaging, and orbital forming. Orbital forming (or orbital forging) is a cold metal forming process during which the workpiece (the base portion 34 in this case) is transformed between upper and lower dies. The process features one or the other of these dies orbiting relative to the other with a compression force applied therebetween. Due to this orbiting motion over the workpiece, the resultant localized forces can achieve a high degree of deformation at a relatively low compression force level. The fully assembled pivoting head 10 is illustrated in FIG. 9 . In this Figure, the lower lip 56 of the base portion 34 is formed to constrain the wear member 30 and the anchor member 18 .
FIG. 10 shows a detail view of the lower lip 56 of the base portion 34 . The forming technique used to form the lower lip 56 under and around the wear member 30 may be controlled to produce a pivoting head 10 with a desired, predetermined resistance to motion. The dashed lines labeled INT 1 and INT 2 depict this ability to control the amount of interference between the parts, and hence the amount of resistance to motion. If a greater amount of resistance to motion is desired, the lower lip 56 may be deformed a greater amount as indicated by the dashed line labeled INT 2 . A lesser amount of deformation indicated by the dashed line INT 1 may produce less resistance to motion. In one embodiment, the lower lip 56 is formed to produce a very large resistance to motion such that the pivoting head 10 is, for all practical purposes, fixed. At the opposite end of the spectrum, the lower lip 56 is formed to merely place the relevant parts (base portion 34 , wear member 30 , and anchor head 32 ) in contact with one another or in close proximity to one another. In this embodiment, the pivoting head 10 is free to rotate with very little or no resistance to motion. At points between these extremes (indicated by dashed line INT 1 ), a desired amount of interference may produce a desirable resistance to motion.
The resistance to motion may be measured in standard torque units, such as inch-ounces or other units of measure. As the parts are formed, the measurable resistance to motion may be marked on the exterior of the pivoting head 10 to provide surgeons an indication of the relative flexibility of the pivoting head 10 . This marking may be provided as an alphanumeric indication as represented by the letter T in FIGS. 2A and 2B . The marking may be stamped, whether by ink or metal deformation, engraved, or otherwise displayed on the pivoting head 10 .
Interference between the base portion 34 , the wear member 30 , and the anchor head 32 will generally contribute to greater amounts of resistance to motion. Accordingly, the parts may be selected according to size to provide the desired resistance to motion. For instance, FIG. 11 shows a pivoting head 10 , including a base portion 34 that is defined in part by a dimension D 1 . This dimension D 1 corresponds approximately to the outer dimension of the wear members 30 b , 30 c , and 30 d that are also shown in FIG. 10 . However, each wear member 30 b - d has a slightly different outer dimension D 2 -D 4 . As an example, wear member 30 b is characterized by the largest outer dimension D 2 . Wear member 30 c is characterized by the smallest outer diameter D 3 and wear member 30 d is somewhere between, with an outer diameter D 4 . It is assumed for the sake of this discussion, that the inner surface 46 is the same for all three wear members 30 b - d . In an alternative embodiment, the inner surface 46 may be constructed with different sizes to create different amounts of interference with the anchor head 32 of the anchor member 18 . In an alternative embodiment, both the inner 46 and outer 44 surfaces may vary between wear members 30 . That is, different wear members 30 may have different thicknesses. In an alternative embodiment, the resistance to pivoting motion of the head 32 may be provided by materials having different coefficients of friction.
For the embodiments shown in FIG. 11 , wear member 30 c will result in the least amount of interference when used in the pivoting head 10 . Conversely, wear member 30 b will result in the greatest amount of interference when used in the pivoting head 10 . A measurable resistance to motion of the pivoting head 10 can be determined once the parts are assembled. As indicated above, this measured resistance to motion may be marked on the exterior of the pivoting head 10 to provide surgeons an indication of the relative flexibility of the pivoting head 10 .
FIG. 12 shows an alternative embodiment of the pivoting head 10 a . The section view shows an alternative technique for retaining the wear member 30 and anchor member 18 within the base portion 34 a . In this embodiment, a snap ring 58 is inserted into the bottom of the base portion 34 a beneath the wear member 30 . The snap ring 58 may effectively retain the wear member 30 and anchor member 18 within the pivoting head 10 a . A detailed view of the area around the snap ring 58 is shown in FIG. 13 . Notably, in this embodiment, the snap ring 58 acts as a barrier to prevent the wear member 30 from escaping but does not contribute to any interference between the other parts ( 30 , 32 , 34 ).
In an alternative embodiment shown in FIG. 14 , a snap ring 158 may contribute to the overall resistance to motion of the pivoting head 10 b . As with the embodiment shown in FIGS. 12 and 13 , the snap ring 158 is configured to fit within the interior of the base portion 34 b . However, the interior portion of the snap ring 158 is modified slightly to create an interference with the wear member 30 e . In this embodiment, the wear member 30 e is slightly modified to include a rounded lower outside corner 60 to facilitate insertion of the snap ring 158 . A detailed view of a cross section of the snap ring 158 is shown in FIG. 15 .
The exemplary snap ring 158 comprises a bottom surface 64 , a top surface 66 , and an outer surface 62 , each of which are configured to fit within the body portion 34 b of the pivoting head 10 b . A retaining surface 68 further acts to keep the wear member 30 e within the pivoting head 10 b . This snap ring 158 also includes an interference surface 70 that contacts the wear member 30 e to create a force G (shown in FIG. 14 ) that compresses the wear member 158 towards the anchor head 32 . The compression force G creates an interference that resists pivoting motion of the anchor head 32 relative to the wear member 30 e . Snap rings 158 including different interference surfaces 72 , 74 may be selected to create more or less interference as desired. Once the snap ring 158 is assembled to retain and compress the wear member 30 e , a measurable resistance to motion of the pivoting head 10 b can be determined. As indicated above, this measured resistance to motion may be marked on the exterior of the pivoting head 10 b to provide surgeons an indication of the relative flexibility of the pivoting head 10 b.
FIGS. 16 and 17 illustrate an alternative embodiment of the pivoting head 10 c . In this embodiment, the resistance to motion may be set intra-operatively. The base portion 34 c of the pivoting head 10 c includes one or more adjustment members 76 that allow a surgeon to adjust the amount of interference between the wear member 30 and the anchor head 32 . Further, a surgeon may be able to adjust this amount of interference differently about different axes depending upon how many adjustment members 76 are provided. In the embodiments illustrated, there are four total adjustment members 76 , disposed approximately 90 degrees apart from one another. More or fewer adjustment members 76 may be provided. Also, in one embodiment, one of the adjustment members 76 is substantially aligned with the orientation in which a longitudinal member 15 lies. For example, in the embodiment shown, one adjustment member 76 is substantially parallel to the seating surface 24 . In one embodiment, an adjustment member 76 is substantially transverse to this seating surface. In the embodiment shown, the adjustment members 76 are setscrews that may be screwed in to create a compressive force H that is shown in FIG. 17 . In another embodiment, the adjustment member 76 may be a pin. The compressive force H may create an increased amount of interference that also creates more resistance to motion.
FIG. 18 shows an alternative embodiment of the pivoting head 10 d that includes a threaded region 78 disposed towards a bottom of the base portion 34 d . An adjustment member 80 having substantially matching threads 84 is threaded onto the threads 78 on the base portion 34 d and rotated until the desired resistance to motion is obtained. This procedure may be performed intra-operatively. In one embodiment, the threads 78 , 84 are tapered threads to create an increasing amount of inward compression J and corresponding interference. In one embodiment, a lower opening 82 of the adjustment member 80 is smaller than a width of the threaded portion 78 of the base portion 34 d . Consequently, the more the adjustment member 80 is threaded onto the base portion 34 d , the base portion 34 d is compressed an increasing amount.
FIG. 19 shows an alternative embodiment of the wear member 30 a that may be used in one or more embodiments disclosed herein. The wear member 30 a also includes a series of gaps 48 a as with the previous embodiment shown in FIG. 6 . However, gaps 48 a do not extend from the bottom surface 52 a to the top surface 50 a . In this embodiment, the top surface 50 a of the wear member 30 a is substantially continuous. In one embodiment, the wear member 30 a comprises four gaps 48 a separated by approximately 90 degrees. In other embodiments, more or fewer numbers of gaps 48 a are used. Since the gaps 48 a originate at the bottom surface 52 a of the wear member 30 a , inward deflection of the wear member 30 a , particularly near the bottom surface 52 a , is possible. This feature may be appropriate for one or more embodiments where inward deflection of the wear member 30 a is used to create a desired resistance to motion.
Embodiments described above have contemplated an anchor member 18 that comprises threads for insertion into a vertebral member V. Certainly, the pivoting head 10 may be incorporated on other types of bone screws. For example, different types of screws may be used to attach longitudinal members 15 to the sacrum S or to other parts of a vertebral member V. These include, for example, anterior and lateral portions of a vertebral body. In other embodiments, such as those shown in FIGS. 20 and 21 , the pivoting head 10 may be implemented on other types of anchoring members. For example, FIG. 20 shows a pivoting head 10 incorporated onto a hook-type anchor member 118 . In another embodiment shown in FIG. 21 , the pivoting head 10 is incorporated onto another type of threaded anchor member 218 that is inserted into a plate 220 instead of a bony member.
Spatially relative terms such as “under”, “below”, “lower”, “over”, “upper”, and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc and are also not intended to be limiting. Like terms refer to like elements throughout the description.
As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.
The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. For example, embodiments described above have contemplated a pivoting head 10 having a substantially U-shaped recess in which to hold a longitudinal member 15 . Certainly other types of configurations may incorporate the articulation mechanism 40 described herein. For example, alternative embodiments of the pivoting head may have circular apertures, C-shaped clamps, and multi-piece clamps as are known to secure a longitudinal member. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
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A pivoting connector couples a vertebral member to a longitudinal member. An anchor is pivotally attached to a body by positioning a head of the anchor within a cavity in the body. A longitudinal rod is inserted into a channel also positioned within the body and axially aligned with the cavity. A retainer applies a force to maintain the longitudinal rod within the channel, however the force may be isolated from the anchor. The cavity is adjustable between a plurality of sizes that apply different resistances to pivoting movement of the anchor relative to the body. The adjustment may be performed before or during a surgical procedure. The adjustment may be performed by inserting different components or by rotating a threaded element to create more or less rotational interference.
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This application claims the benefit of Provisional application No. 60/298,627 filed Jun. 14, 2001.
The present invention relates to an actuator for an electrical switch, particularly a standard wall toggle switch. The present invention provides a decorative yet functional alternative to the toggle switch, the invention providing a fluid switching motion between the ends of the range of motion of the toggle switch.
BACKGROUND OF THE ART
The standard wall toggle switch is well known in the United States and in many other countries. This type of switch is used to control electric current flow to electrical outlets, lights, ceiling fans and the like. U.S. Pat. No. 5,806,665 to Houssian distinguishes itself from some prior art actuators or switch covers in that Houssian teaches a switch actuator that moves in a circular arc motion rather than linearly. Since the toggle switch arm is a lever that is pinned to and pivots about a central point, the end of the arm away from the pivot point moves in a circular arc with respect to that point. The linear actuators do not move smoothly through their range of motion when required to accommodate this arcuate action of the arm end. In Houssian, the actuator is seated atop the arm end and rides in a channel on an arcuate face plate or cover, albeit one with a larger radius of curvature than that of the toggle arm end.
Certainly a large number of design alternatives are available to the person who is willing to disconnect the electrical contacts to the standard toggle switch assembly, remove that switch assembly from the housing and replace the entire switch assembly. Such persons may, for example, install a switch that offers a resilient “on-off” compression member in combination with a rheostatically controlled rotary element that dims or brightens the light.
A reason for inventions such as Houssian is to provide efficient yet attractive alternatives to the toggle switch while not requiring the installer to work with the electrical connections. An advantage of the present invention is to provide another such alternative.
SUMMARY OF THE INVENTION
This advantage and others are provided by a device for actuating an electrical switch having a toggle switch arm mounted in a base such that when the toggle switch arm pivots from a first position to a second position, electrical contacts in the base are moved from a contacting condition to a non-contacting condition or vice versa. The device comprises a face plate, an actuating assembly and a cap assembly. The actuating assembly is mounted on the face plate. It comprises a means for receiving the toggle switch arm such that a linear movement of the receiving means moves the toggle switch arm from the first to the second position or vice versa. The cap assembly is mounted on the face plate, and is structurally independent of the actuating assembly.
In some embodiments of the device, the cap assembly is a singular piece, comprising a cap.
In other embodiments, the cap assembly comprises an annular ring, mountable in the face plate, and a cap, mountable on the annular ring.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood when reference is made to the accompanying drawings, wherein identical parts are identified with identical reference numerals and wherein:
FIG. 1 shows a standard toggle switch;
FIG. 2 shows an exploded view of the actuator of a first embodiment of the present invention;
FIG. 3 shows an external view of the assembled actuator of the first embodiment of the present invention;
FIG. 4 shows an external view of the assembled actuator of a second embodiment of the present invention;
FIG. 5 shows an isolated view of the ring of either the first or second embodiment device;
FIG. 6 shows an assembled view of the face plate and actuator of the second embodiment, with the cap assembly removed;
FIG. 7 shows an isolated view of the face plate of the second embodiment, with the actuator removed; and
FIG. 8 shows an isolated view of the bridging assembly.
DETAILED DESCRIPTION OF THE INVENTION
The standard wall toggle switch 10 known in the prior art is shown in FIG. 1 . In this switch 10 , the arm 12 is pivotably mounted in a base of the switch, the base containing electrical contacts capable of making and breaking an electrical circuit as the arm moves from a first position to a second position or vice versa. The range of motion of the arm 12 in going from either end position to the other is about thirty degrees. The switch 10 conventionally has a face plate 14 which is generally parallel to and offset from a wall W in which the switch 10 is mounted. This face plate 14 is conventionally attached to the switch 10 by a pair of screws 16 , the screws passing through the face plate in holes 18 . Additionally, a larger hole 20 allows passage of the arm 12 therethrough, the arm being conventionally seated in an arm housing 22 with a rectangular face 24 that is slightly smaller than the hole 20 . Removal and replacement of the face plate 14 presents only an extremely remote danger of electrical shock to the person making the replacement.
The light switch actuator 50 of a first embodiment of the present invention is now shown in FIGS. 2 and 3. FIG. 2 shows an exploded view of the components and FIG. 3 shows an assembled view. The actuator 50 comprises a face plate 52 , an actuating assembly 54 and a cover or cap assembly 56 . In the particular embodiment shown, the cover or cap assembly 56 actually comprises two separate pieces, the first being an elliptical annular ring 58 and the second being a cap 60 . It will be understood that in some embodiments, the cap assembly 56 will consist only of a single part comprising all the features of the ring 58 and the cap 60 .
Attention is now directed to the face plate 52 , which is different from the face plate 14 of the prior art. Face plate 52 has a pair of holes 18 which correspond to the holes 18 in the prior art face plate 14 and a hole 20 which corresponds to the arm housing receiving hole 20 of the prior art face plate. Particularly, the face plate 52 is also provided with a means 62 for receiving and retaining the actuating assembly 54 . In the specific embodiment illustrated, the receiving and retaining means 62 is a set of rectangular holes 64 , with a pair of such holes straddling each of the holes 18 . The face plate 52 also is provided with a means 66 for receiving and retaining the cap assembly 56 . In the particular embodiment shown, the receiving and retaining means 66 is an elliptical ridge 68 , particularly one molded into the upper surface of the face plate 52 .
Further attention to FIG. 2 shows details of the cap assembly 56 , which comprises the elliptical annular ring 58 and the cap 60 . Elliptical annular ring 58 is generally unremarkable, but it will be provided with means so that it will assist the face plate 52 in receiving and retaining the cap 60 . Absent such means being provided, the elliptical annular ring 58 will not be included in the cap assembly 56 . Cap 60 is shown as comprising an elliptical base 70 upon which is based a dome member 72 . In the particular embodiment shown, this dome member 72 is shaped as one-half of a solid of rotation of an ellipse. The dome member 72 is effectively hollow, the thickness of the wall that defines both the dome member and the elliptical base being effectively constant. This hollow dome member 72 thereby provides a cavity within which the toggle arm 12 may move freely within its normal range of motion. The dome member 72 has a first and a second cutout portion 74 , 76 , the use of which will become obvious as further description is provided.
Attention is now directed to the actuating assembly 54 , which has a base 78 with first and second ends 80 , 82 . Connecting arms 84 , 86 , join the first and second ends 80 , 82 , to provide structural stability. Each end 80 , 82 , is also provided with means 90 corresponding with the means 62 for receiving and retaining on the face plate 52 . In the embodiment illustrated, the means 90 is a set of legs of rectangular cross-section. Each end 80 , 82 , is also provided with a pair of spaced apart, upstanding legs 94 . These legs 94 define a clevis for supporting a pivot bar 96 . A first pivot element 98 is held in the clevis formed by the upstanding legs 94 at the first end 80 of the actuating assembly 54 and a second pivot element 100 is held in the clevis formed by the upstanding legs 94 at the second end 82 thereof. A bar member 102 has its first end 104 pinned into the first pivot element 98 and its second end 105 pinned into the second pivot element 100 , so that pivoting motion of either pivot element causes co-action in the other pivot element. A means 106 for receiving the toggle arm 12 is positioned on an intermediate portion of the bar member 102 . In this manner, the pivoting motion of either of the pivot elements 98 , 100 , results in motion of the toggle arm 12 . The toggle arm receiving means is shown in the embodiment as a pair of downwardly extending tangs or posts 108 , 110 , with an intermediate cavity or cradle 112 into which the toggle arm 12 is seated. When the actuating assembly 54 is properly constructed, a pivoting rotation of either the first or second pivot element 98 , 100 , through about 90 degrees will result in a full range motion of about thirty degrees in the toggle arm 12 . Each of the pivot elements 98 , 100 , pivot in the same direction, so that, in the embodiment shown, a counterclockwise rotation of the pivot elements moves the toggle arm 12 counterclockwise and a clockwise rotation of the pivot elements moves the toggle arm clockwise. It will also be appreciated that the bar member 102 remains generally parallel to the face plate 52 as it moves through its range of motion, with the bar member being closest to the face place at the ends of the range and farthest from the face plate at the middle of the motion.
Further attention is now directed to the pivot elements 98 , 100 , which, in the embodiment shown, are mirror images of each other. Each pivot element 98 , 100 has a first pivot point 120 and a second pivot point 122 . The respective first pivot points 120 provide the pivot between the pivot element 98 , 100 and the upstanding legs 94 of the bridging assembly. the respective second pivot points 122 provide the pivot between the pivot element 98 , 100 and the respective ends 104 of the bar member 102 . A periphery of each of the pivot elements 98 , 100 , is irregular when viewed from the side and the first pivot point 120 is offset from a center of the planar surface defined by the periphery. Because of this, a portion 124 of each pivot element 98 , 100 , can extend outwardly through one of the cutout portions 74 , 76 when the pivot element is in one position, but the pivot element 98 , 100 will be effectively flush with the surface of the dome member when the pivot element is in a second position.
It will be understood from the foregoing that when pivot element 98 is in the first position, the pivoting of it about its first pivot point moves pivot element 98 to the second or flush position and the action of bar member 102 not only moves the toggle arm, but also changes pivot element 100 from the second or flush position to the first or outwardly extended position. FIG. 3 shows an example of this situation with pivot element 98 in the flush position and pivot element 100 in the extended position.
While this motion of the pivot elements should move smoothly, it may be desirable in some embodiments to connect the bar member 102 to the face plate 52 or the actuating assembly 54 with a biasing means, such as a spring. This biasing means will urge the bar member 102 to be in one of the ends of its range of motion rather than in any intermediate position, meaning that the toggle arm 12 will likewise be at one end of its motion range also, rather than being in an intermediate position.
A second embodiment of the light switch actuator 150 is now shown in FIGS. 4 through 8. This actuator 150 comprises a face plate 152 , a actuator 154 and a cover or cap assembly 156 . In the particular embodiment shown, the cover or cap assembly 156 actually comprises two separate pieces, the first being an elliptical annular ring 58 and the second being a cap 160 . It will be understood that in some embodiments, the cap assembly 156 will consist only of a single part comprising all the features of the ring 58 and the cap 160 . The assembled device 150 is shown in FIG. 4, in a manner similar to FIG. 3 for the first embodiment. FIG. 5 shows the ring 58 in isolation. FIG. 6 shows the face plate 152 and actuator 154 together. FIG. 7 shows the isolated face plate 152 and FIG. 8 shows the isolated actuator 154 .
Attention is now directed to the face plate 152 , which is different from the face plate 14 of the prior art. Face plate 152 has a pair of holes 18 which correspond to the holes 18 in the prior art face plate 14 and a hole 20 which corresponds to the arm housing receiving hole 20 of the prior art face plate. Particularly, the face plate 152 is also provided with a means 162 for receiving and retaining the actuator 154 . Unlike the first embodiment, in which the receiving and retaining means 62 is a set of rectangular holes 64 , the receiving and retaining means 162 on the face plate 152 is a pair of upstanding legs 165 . Instead of straddling the holes 18 , the legs 165 straddle hole 20 , so they are more centrally positioned. In the embodiment shown, the legs 165 are not parallel to each other, but they are positioned so as to splay apart slight as the distance from a point of attachment to the face plate increases. Further, each leg is provided with an enlarged lip or edge 167 at the end of the leg that is distant from the attachment point. These legs 165 interact with corresponding means on the actuator 154 as described in more detail below.
The face plate 152 also is provided with a means 66 for receiving and retaining the cap assembly 56 . In the particular embodiment shown, the receiving and retaining means 66 is an elliptical ridge 68 , particularly one molded into the upper surface of the face plate 152 . This means may be accompanied by an even further or second means for receiving and retaining the cap assembly, that further means being the upstanding legs 165 , or more particularly, the edges or lips 167 on the legs. This second means is also described in more detail below.
Further attention to FIG. 4 shows details of the cap assembly 156 , which comprises the elliptical annular ring 58 and the cap 160 . Elliptical annular ring 58 is generally unremarkable, but it will be provided with means so that it will assist the face plate 52 in receiving and retaining the cap 160 . Absent such means being provided, the elliptical annular ring 58 will not be included in the cap assembly 56 . Cap 160 is shown as comprising an elliptical base 70 upon which is based a dome member 172 . In the particular embodiment shown, this dome member 172 is shaped as one-half of a solid of rotation of an ellipse. The dome member 172 is effectively hollow, the thickness of the wall that defines both the dome member and the elliptical base being effectively constant. This hollow dome member 172 thereby provides a cavity within which the toggle arm 12 may move freely within its normal range, of motion. The dome member 172 has a first and a second cutout portion 74 , 76 , the use of which will become obvious as further description is provided.
Dome member 172 differs from dome member 72 of the first embodiment in that it is further provided on the inside surface with a pair of linear depressions or detents 173 which correspond spatially to the lips or edges 167 of the upstanding legs 165 when the dome member is properly seated on the face plate 152 . The depressions or detents coact with the edges 167 to frictionally hold the dome member and the face plate in proper position.
Attention is now directed to the actuator 154 , which has a base 78 with first and second ends 80 , 82 . Connecting arms 184 , 186 , join the first and second ends 80 , 82 , to provide structural stability. Each connecting arm 184 , 186 is provided with means 190 corresponding with the means 162 for receiving and retaining on the face plate 152 . In the second embodiment, the means 190 is a pair of holes 191 , one such hole in each connecting arm 184 , 186 so that one of the upstanding legs 165 may be passed through the hole 191 . The slight outward splay of the legs 165 relative to each other urges the actuator 154 against the face plate 152 , securing it in place. As in the first embodiment, each end 80 , 82 , is also provided with a pair of spaced-apart, upstanding legs 94 . These legs 94 define a clevis for supporting a pivot point. A first pivot element 98 is held in the clevis formed by the upstanding legs 94 at the first end 80 of the actuator 154 and a second pivot element 100 is held in the clevis formed by the upstanding legs 94 at the second end 82 thereof. A bar member 102 has its first end 104 pinned into the first pivot element 98 and its second end 105 pinned into the second pivot element 100 , so that pivoting motion of either pivot element causes co-action in the other pivot element. A means 106 for receiving the toggle arm 12 is positioned on an intermediate portion of the bar member 102 . In this manner, the pivoting motion of either of the pivot elements 98 , 100 , results in motion of the toggle arm 12 . The toggle arm receiving means is shown in the embodiment as a pair of downwardly extending tangs or posts 108 , 110 , with an intermediate cavity or cradle 112 into which the toggle arm 12 is seated. When the actuator 154 is properly constructed, a pivoting rotation of either the first or second pivot element 98 , 100 , through about 90 degrees will result in a full range motion of about thirty degrees in the toggle arm 12 . Each of the pivot elements 98 , 100 , pivot in the same direction, so that, in the embodiment shown, a counterclockwise rotation of the pivot elements moves the toggle arm 12 counterclockwise and a clockwise rotation of the pivot elements moves the toggle arm clockwise. It will also be appreciated that the bar member 102 remains generally parallel to the face plate 52 as it moves through its range of motion, with the bar member being closest to the face place at the ends of the range and farthest from the face plate at the middle of the motion.
As in the first embodiment, the pivot elements 98 , 100 are mirror images of each other. Each pivot element 98 , 100 has a first pivot point 120 and a second pivot point 122 . The respective first pivot points 120 provide the pivot between the pivot element 98 , 100 and the upstanding legs 94 of the bridging assembly. The respective second pivot points 122 provide the pivot between the pivot element 98 , 100 and the respective ends 104 , 105 of the bar member 102 . A periphery of each of the pivot elements 98 , 100 , is irregular when viewed from the side and the first pivot point 120 is offset from a center of the planar surface defined by the periphery. Because of this, a portion 124 of each pivot element 98 , 100 , can extend outwardly through one of the cutout portions 74 , 76 when the pivot element is in one position, but the pivot element 98 , 100 will be effectively flush with the surface of the dome member when the pivot element is in a second position.
It will be understood from the foregoing that the when pivot element 98 is in the first position, a pivoting of it about its first pivot point moves pivot element 98 to the second or flush position and the action of bar member 102 not only moves the toggle arm, but also changes pivot element 100 from the second or flush position to the first or outwardly extended position. FIG. 4 shows an example of this situation with pivot element 98 in the flush position and pivot element 100 in the extended position.
While this motion of the pivot elements should move smoothly, it may be desirable in some embodiments to connect the bar member 102 to the face plate 52 or the actuating assembly 54 with a biasing means, such as a spring. This biasing means will urge the bar member 102 to be in one of the ends of its range of motion rather than in any intermediate position, meaning that the toggle arm 12 will be at one end of its motion range also, rather than being in an intermediate position.
In the first embodiment, the pinning of the pivot elements 98 , 100 to the upstanding legs 94 and the bar member 102 is accomplished by pins, typically a metal pin 96 passing through holes in the respective parts, as illustrated in FIG. 2 . However, it is also possible to provide tangs on one of the parts, the tangs fitting into the hole and effectively replacing the pivot bar.
It will be further understood from the foregoing that all elements of the present invention responsible for switching the toggle arm 12 from one position to the other are structurally independent from the cap assembly.
It is known in the prior art to have a light source, typically a small incandescent bulb or even a light emitting diode (“LED”) light installed in a light switch, especially behind the face plate of a conventional wall switch. In some instances, especially with dimmer switches, the light that is installed is lighted when the switch is in the open or “off” position and is not lighted when the switch is in the closed or “on” position. Because the present invention teaches a light switch actuator involving a cap assembly that covers over the toggle arm, there i sat least as much room for installation of such a light source. While the prior art the tendency has been to use alternating current available in the house electrical supply to power the light source, the increasing use of small “button”-type batteries suggests that they could be used in this application.
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A decorative electrical switch actuator ( 50, 150 ) acts in combination with a conventional light switch ( 10 ) having a toggle switch arm ( 12 ) mounted in a base such that when the toggle switch arm pivots from a first position to a second position, electrical contacts in the base are moved from a contacting condition to a non-contacting condition or vice versa. The decorative switch actuator has a face plate ( 52 ), an actuating assembly ( 54 ), and a cap assembly ( 56, 156 ). The actuating assembly is mounted on the face plate, and has a means ( 106 ) for receiving the toggle switch arm such that a linear movement of the receiving means moves the toggle switch arm from the first to the second position or vice versa. The cap assembly ( 56, 156 ) is mounted on the face plate, and is structurally independent of the actuator.
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to an FM signal demodulator for demodulating a frequency modulated video signal widely used in satellite television broadcasts or the like. Particularly, the present invention relates to an apparatus for providing stable demodulation performance by reducing interference caused by oscillation component radiates and leaks into the input stage of the apparatus.
DESCRIPTION OF THE PRIOR ART
In a satellite television broadcast, frequency modulation (FM) is used for transmitting video signals. The FM signal is demodulated at a 400 MHz band. This is called the second intermediate frequency (IF). Recently, it has been proposed that the FM signal demodulator using a phase locked loop be formed on integrated circuits (IC) to miniaturize the apparatus and reduce power consumption.
FIG. 1(a) is a block diagram of an FM signal demodulator in accordance with the prior art. A wide band FM signal having a second IF of 400 MHz is modulated by a video signal. The wide band FM signal is provided to a second IF input terminal 1. A surface acoustic wave (SAW) bandpass filter 2, a channel filter, is used for removing signals outside the band and noise. A second IF amplifier 3 amplifies the selected signal to a desired level to demodulate the FM signal. The second IF amplifier 3 is an amplifier with a constant gain or a variable gain amplifier which is set to a desired gain by a control signal.
A phase comparator 12 (1) detects a phase difference between an inputted FM signal and an output signal of a voltage controlled oscillator 18 and (2) outputs a DC voltage corresponding to the phase difference. The output is a video signal including a DC component which is supplied to demodulator output terminals 16 and 17 through a low pass filter composed of first and second differential amplifiers 13 and 15, respectively, and is negatively fedback to the voltage controlled oscillator 18. Thus, a phase locked loop is formed.
The voltage controlled oscillator 18 is made into an IC by using the circuit shown in FIG. 1(b) according to, for example, Japanese Patent Publication Laid Open 2-21707. The DC source voltage for the voltage-controlled oscillator 18 is supplied from terminal 30. A high level signal such as the oscillation signal can cause interference with the other circuits inside the IC. Accordingly, a differential amplifier composed of transistors 33 and 34 is used and the balanced signals output from the collectors of the transistors 33 and 34 are supplied to the phase comparator 12. Capacitors 36 and 37 are connected in series from a collector of transistor 34 to a base of transistor 33 and capacitors 38 and 39 are connected in series from a collector of transistor 33 to a base of transistors 34. These connections provide positive feedback to the transistors. An anode of a variable capacitance diode 40 and a terminal of an air-core coil 46 are connected to a junction of capacitors 36 and 37. An anode of a variable capacitance diode 41 and a terminal of air-core coil 45 are connected to a junction of capacitors 38 and 39. The other terminals of the air-core coils 45 and 46 are grounded. Cathodes of the variable capacitance diodes 40 and 41 are connected to each other and to a control terminal 44 through resistor 42 and air-core coil 43 connected in series.
The voltage controlled oscillator 18 oscillates at a resonance frequency determined by a resonant circuit composed of the variable capacitance diodes 40 and 41 and the air-core coils 45 and 46. The voltage controlled oscillator 18 is a frequency modulator controlled by the video signal demodulated output. Accordingly, it is desirable that an output impedance of the second differential amplifier 15 at the control terminal 44 is as low as possible to follow variations in the video signal at the video signal frequency band of less than 10 MHz. It is desirable that the impedance at the junction between the variable capacitance diodes 40 and 41 is high enough at the 400 MHz band to normally oscillate at the high second IF of 400 MHz. A high impedance is obtained by connecting resistor 42 and air-core coil 43 in series.
Because the FM signal demodulator shown in FIG. 1(a) forms a phase locked loop, the frequency of an input FM signal coincides with the oscillation frequency of the voltage controlled oscillator 18 in a synchronization state. When the second IF is a center frequency, for example, when the output voltage of the second differential amplifier 15 becomes a center value of the demodulated output voltage, it is desirable that the second differential amplifier 15 is in an equilibrium state. Then, it is also desirable that the output voltage is at a center value of the dynamic range and that the dynamic range of the demodulation characteristic is at a maximum.
It is also desirable that the linearity of the oscillation frequency against the control voltage of the voltage controlled oscillator 18 is set at this voltage.
The oscillation frequency of the voltage controlled oscillator 18 is determined by the variable capacitance diodes 40 and 41 and the air-core coils 45 and 46. The variable capacitance diodes 40 and 41 usually have a capacitance dispersion of about ±15% when their cross terminal voltages are constant.
Due to this dispersion, the voltage controlled oscillator 18 does not always oscillate at the center frequency at the center of the output dynamic range of the second differential amplifier 15. Accordingly, in the prior art, the coil inductance is varied by widening or narrowing the winding gaps of the air-core coil 45 or 46 and thus, the oscillation frequency is adjusted by compensating the dispersion of the variable capacitance diodes so that the voltage controlled oscillator 18 oscillates at the center frequency at the center of the output dynamic range of the second differential amplifier 15.
A differential balance controller 14 adjusts the oscillation frequency of the voltage controlled oscillator 18 so that it coincides with the center frequency of the second IF frequency when the FM signal is not supplied to the phase comparator. Thus a free running frequency of a phase locked loop type FM signal demodulator is adjusted.
Recently, almost all functions concerning FM signal demodulation such as second IF amplifier 3, phase comparator 12, second differential amplifier 15, voltage controlled oscillator 18, a detector for an automatic frequency controller (AFC), and a detector for an automatic gain controller (AGC) have been integrated into an IC. Some developments are being pursued which would include more peripheral circuit elements in the IC. There is also a trend to increase the gain of the second IF amplifier 3 as high as possible and to increase input sensitivity of the IC.
The output signal of the demodulated output terminal 16 and the reference voltage 19 are supplied to a voltage comparator 20. Because the output voltage of the FM signal demodulator is proportional to the frequency of the inputted FM signal, frequency comparison can be done at voltage comparator 20. The voltage of the reference voltage source 19 is adjusted to a voltage corresponding to the frequency to be compared. Thus, the output signal at the output terminal 21 of the voltage comparator 20 can be used as a control voltage for AFC.
In the circuit configuration in accordance with the prior art, however, the modulated output voltage does not always reach the center of the dynamic range of the second differential amplifier 15 at the center frequency of the second IF signal, because of the capacitance dispersion of the variable capacitance diodes 40 and 41. Therefore, the oscillation frequency of the voltage controlled oscillator 18 is adjusted by widening or narrowing the winding gaps of the air-core coils 45 and 46. But the adjustment of the air-core coils is not easily performed as that of the variable resistors. In addition, precise adjustment of the air-core coils is very difficult.
Although the circuit configuration in accordance with the prior art can reduce interference due to a radiating signal, when the air-core coils 40 and 41 are inserted in a printed circuit board, the oscillation signal component radiates from the air-core coils 40 and 41 to the rear surface of the board or to the air. In addition, leaks into the input of the FM signal demodulator can result. As a result, interference can occur easily.
Interference can occur easily because, as noted above, the IC has a high input sensitivity. In addition, as a channel filter, SAW filter 2 has been recently used for non-adjustment and for providing a good cutoff characteristic. However, the insertion loss of the SAW filter can be approximately 25 dB. Because this insertion loss is much bigger than that of a usual LC filter (about 4 dB) and the output signal level is low, performance deterioration is promoted by radiating and leaking of the oscillation signal component.
FIG. 2 shows a frequency characteristic from the input terminal 1 to the monitor terminal 7 of the second IF signal in FIG. 1. Wave form A is the characteristic when the voltage controlled oscillator 18 stops oscillation and wave form B is the characteristic when the voltage controlled oscillator 18 normally oscillates and the phase locked loop synchronizes. The signal from the voltage-controlled oscillator 18 leaks to the input stage of the FM signal demodulator causing interference and the wave form of the SAW bandpass filter 2 to be disturbed. This is because the signal from the voltage controlled oscillator 18 synchronizes with the input FM signal leaks causing an interference signal which is superimposed on the original signal with a deviated phase and a deviated amplitude. A similar phenomenon to this phenomenon occurs in a transmission system where multiple reflections occur. As a result, the characteristics of the demodulated video signal such as differential gain, differential phase and the like are deteriorated.
SUMMARY OF THE INVENTION
The present invention relates to an FM signal demodulator which is easy to adjust and produce.
The present invention further relates to an FM signal demodulator which (1) reduces the occurrence of interference due to radiating and leaking of the oscillation signal component of a voltage-controlled oscillator to the input stage of the FM signal demodulator and (2) provides stable demodulation performance.
An FM signal demodulator in accordance with an exemplary embodiment of the present invention includes a voltage controlled oscillator which varies the oscillation frequency by controlling variable capacitance diodes which are resonant elements of a resonance circuit using a DC voltage supplied to a control terminal. Also provided is a phase comparator which produces a DC output by comparing the phase of the inputted IF signal and the phase of the signal from the voltage controlled-oscillator. Also included is a differential amplifier which has a variable reference voltage source and a demodulated signal output which is produced by amplifying the output of the phase comparator. In addition, the demodulated output of the differential amplifier is negatively fed back to the control terminal of the voltage controlled oscillator.
In an exemplary embodiment of the present invention, a center frequency of the IF signal is provided to the phase comparator and the reference voltage of the differential amplifier is adjusted while the IF signal and the signal of the voltage-controlled oscillator are synchronized in the negative feedback loop. In addition, the DC levels of the balanced outputs of the differential amplifier are adjusted and a deviation from equilibrium at the differential amplifier due to capacitance dispersion of the variable capacitance diodes is compensated.
An FM signal demodulator in accordance with a second exemplary embodiment of the present invention includes a voltage-controlled oscillator which varies the oscillation frequency by controlling the capacitances of the variable capacitance diodes which are resonant elements of a resonance circuit using a DC voltage supplied to a control terminal and a fine adjustment reference voltage. Also included is a phase comparator which provides a DC output corresponding to a phase difference produced by comparing the phase of the inputted IF signal and the phase of the voltage-controlled oscillator signal. A differential amplifier is also included to produce a demodulated signal by amplifying the output of the phase comparator. The demodulated output of the differential amplifier is negatively fed back to the control terminal of the voltage-controlled oscillator.
In a second exemplary embodiment of the present invention, the center frequency of the IF signal is inputted to the phase comparator and the oscillation frequency is varied by controlling the variable capacitance diodes which are resonant elements of a resonance circuit using a reference voltage of the voltage-controlled oscillator while the IF signal and the signal of the voltage controlled oscillator are synchronized in the negative fedback loop. In addition, the DC levels of the balanced outputs of the differential amplifier are adjusted and a deviation from equilibrium at the differential amplifier due to the capacitance dispersion of the variable capacitance diodes is compensated.
An FM signal demodulator in accordance with a third exemplary embodiment of the present invention includes a voltage-controlled oscillator which provides a differential amplifier positively fedback by a resonance circuit composed of a pair of variable capacitance diodes. Also included is a pair of micro strip lines which have substantially the same length. Also included is a differential amplifier which is positively fed back by capacitors which vary the oscillation frequency by controlling the variable capacitance diodes which are resonant elements of a resonance circuit using a DC voltage supplied to a control terminal. A phase comparator is also provided for producing a DC output corresponding to a phase difference which corresponds to the phase of the inputted IF signal compared to the phase of the voltage-controlled oscillator signal. A differential amplifier is also included for producing a demodulated signal by amplifying the output of the phase comparator. The demodulated output of the differential amplifier is negatively fed back to the control terminal of the voltage-controlled oscillator.
In a third exemplary embodiment of the present invention, the voltage controlled oscillator oscillates in a state which keeps the differential amplifier at a balanced differential and the generation of an in-phase component from the oscillation signal is reduced. In addition, by using micro strip lines, most of the oscillation power of the voltage-controlled oscillator exists inside the dielectric of the printed circuit board preventing it from being radiated into the air. Thus, interference caused by radiating and leaking of the oscillation power to the input side of the demodulator is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(a) is a circuit diagram, partly in block diagram form, of part of a phase locked loop type FM signal demodulator in accordance with the prior art.
FIG. 1(b) is a circuit diagram of a voltage controlled oscillator 18, shown in FIG. 1(a), used in the phase locked loop type FM signal demodulator in accordance with the prior art.
FIG. 2 is a graph of the frequency characteristic from an input terminal 1 to a monitor terminal 7 for a second IF signal in the phase locked loop type FM signal demodulator shown in FIG. 1(a) in accordance with the prior art.
FIG. 3(a) is a block diagram of part of a phase locked loop type FM signal demodulator in accordance with a first exemplary embodiment of the present invention.
FIG. 3(b) is a circuit diagram of a voltage controlled oscillator 18a, shown in FIG. 3(a), used in the phase locked loop type FM signal demodulator in accordance with the first exemplary embodiment of the present invention.
FIG. 4(a) is a circuit diagram of a second differential amplifier 15a, shown in FIG. 3(a), used in the phase locked loop type FM signal demodulator in accordance with the first exemplary embodiment of the present invention.
FIG. 4(b) is an input-output voltage characteristic of the second differential amplifier 15a, shown in FIG. 4(a), used in the phase locked loop type FM signal demodulator in accordance with the first exemplary embodiment of the present invention.
FIG. 5(a) is a block diagram of part of a phase locked loop type FM signal demodulator in accordance with a second exemplary embodiment of the present invention.
FIG. 5(b) is a circuit diagram of a voltage-controlled oscillator 18b, shown in FIG. 5(a), used in the phase locked loop type FM signal demodulator in accordance with the second exemplary embodiment of the present invention.
FIG. 6 is an input-output voltage characteristic of a second differential amplifier 15b, shown in FIG. 5(a), used in the phase locked loop type FM signal demodulator in accordance with the second exemplary embodiment of the present invention.
FIG. 7(a) is a block diagram of part of a phase locked loop type FM signal demodulator in accordance with a third exemplary embodiment of the present invention.
FIG. 7(b) is a circuit diagram of a voltage controlled oscillator 18c, shown in FIG. 7(a), used in the phase locked loop type FM signal demodulator in accordance with the third exemplary embodiment of the present invention.
FIG. 8 is a frequency characteristic from an input terminal 1 to a monitor terminal 7 of a second IF signal in the phase locked loop type FM signal demodulator, shown in FIG. 7(a), in accordance with the third exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
First exemplary embodiment
FIG. 3(a) is a block diagram of part of a phase locked loop type FM signal demodulator in accordance with a first exemplary embodiment of the present invention. The phase locked loop type FM signal demodulator includes a phase comparator 12, a first differential amplifier 13, a differential balance adjusting circuit 14 and a voltage-controlled oscillator 18 having similar functions to those in the prior art shown in FIG. 1(a). Accordingly, their detailed explanations are omitted.
A variable reference voltage is supplied from a reference voltage source 22 to a second differential amplifier 15a. Two input terminals of voltage comparator 20a are connected to balanced demodulator output terminals 16 and 17 of the second differential amplifier 15a to provide outputs proportional to the output difference between the demodulator output terminals 16 and 17 at terminal 21a. The demodulator output terminal 16 is connected to a control terminal 44 of a voltage-controlled oscillator 18a to form a negative feedback loop and, thus, a phase locked loop is formed.
FIG. 3(b) is a circuit diagram of the voltage-controlled oscillator 18a. The circuit elements having similar functions to those in FIG. 1(b) are numbered with the same reference numbers and, thus, their detailed explanations are omitted.
The voltage-controlled oscillator 18a oscillates at a resonance frequency determined by a resonant circuit composed of variable capacitance diodes 40 and 41 and air-core coils 45 and 46 similarly to that of the prior art. The voltage-controlled oscillator 18a is a frequency modulator controlled by a demodulated video signal output. It is desirable for video frequency bands under 10 MHz to make the output impedance of the second differential amplifier 15a seen from the control terminal 44 as low as possible so variations in the video signal are followed. The impedance at the junction point between the variable capacitance diodes 40 and 41 looking towards the control terminal 44 is desirably set high when oscillating at the second IF frequency of 400 MHz. Therefore a high impedance is provided by a series connection of resistor 42 and air-core coil 43.
Here, capacitors 36, 38 and 37, 39 are selected to have substantially the same capacitance which approximately is 3 pF. Resistor 42 is 39 ohms and the inductance of the air-core coil 43 is 120 nH.
A circuit diagram of the second differential amplifier 15a is shown in FIG. 4(a).
The differential amplifier 15a is a DC amplifier for amplifying a phase difference signal including the video signal. The differential amplifier includes a differential amplifier including transistors 52 and 53 coupled to buffer amplifiers including transistors 58 and 59. The differential amplifier 15a amplifies the inputted phase difference signal and outputs the signal at a low impedance after adjusting the in-phase signal level using variable reference voltage source 22.
FIG. 4(b) is an input-output voltage characteristic of the second differential amplifier 15a. In FIG. 3(a), a wide band FM signal modulated by a video signal is supplied from input terminals 10 and 11 of the second IF signal to a phase comparator 12 as a second IF signal at 400 MHz. The phase comparator 12 detects a phase difference between the frequency modulated input signal and the output signal of the voltage controlled oscillator 18a and outputs a DC voltage signal corresponding to the phase difference. The DC voltage signal is outputted to the demodulator output terminals 16 and 17 through a low pass filter including a first differential amplifier 13 and the second differential amplifier 15a and at the same time it is negatively fed back to the voltage-controlled oscillator 18a. Thus, a phase locked loop is formed.
When the center frequency signal of the second IF is supplied to a phase locked loop as described above, the voltage-controlled oscillator 18a oscillates at the center frequency of the second IF signal because it is phase locked. However, because the variable capacitance diodes 40 and 41 usually have a capacitance dispersion of about ±15% for a constant cross terminal voltage, the characteristic of the oscillation frequency against the cross terminal voltage is not constant. That is, the output voltage of the second differential amplifier 15a varies and, as a result, the second differential amplifier 15a is not always in equilibrium. This is explained below using FIG. 4(b).
When the capacitance values of the variable capacitance diodes 40 and 41 are the standard value, the voltage-controlled oscillator 18a oscillates at a center frequency of the second IF at the standard control voltage and the working point of the apparatus is point A as shown in FIG. 4(b).
When the capacitance values of both variable capacitance diodes 40 and 41 are larger than the standard value (e.g. center value of design), it is necessary to supply a higher control voltage than the standard voltage to the control terminal 44 so the voltage-controlled oscillator 18a oscillates at the center frequency of the second IF. Therefore, the second differential amplifier 15a moves from equilibrium and the working point becomes point B shown in FIG. 4(b). At this time, a voltage is produced at output terminal 21a of the voltage comparator 20a corresponding to an output difference between terminals 62 and 63 which correspond to demodulator output terminals 16 and 17.
Accordingly, the working point becomes point C because the voltage of the reference voltage source 22 provides a supply voltage to the second differential amplifier 15a which is adjusted to be higher causing the output voltage at the equilibrium point of the input voltage to be adjusted higher. At this time, the second differential amplifier 15a is in equilibrium. During an adjustment, the voltages at terminals 62 and 63 are supplied to the voltage comparator 20a and the voltage of the reference voltage source 22 is adjusted so that the voltage difference between the working points B and E is minimized. The voltage comparison output from output terminal 21a of voltage comparator 20a can be used as a control voltage for an automatic frequency control (AFC) circuit. In addition, two voltage comparators which have an input voltage comparison characteristic which deviates a little bit from the equilibrium may be included for providing a dead zone (e.g. a permitted limit of frequency of the second IF signal from a specific value) when necessary for controlling the AFC circuit. In this case, a range of ±150 kHz from the second IF signal is usually selected as the dead zone.
The frequency or, the second IF signal which is inputted to the terminals 10,11 in FIG. 3(a) changes in steps since the phase locked loop circuit is included for generating the second IF signal. An automatic frequency control (AFC) circuit (not shown), which adjusts the frequency of the second IF signal, ends the adjustment and fixes the frequency when the frequency is entered in the permitted limit of ±150 kHz from the specific value since more adjustment makes the frequency jump to the next step out of the permitted limit.
In the FM signal demodulator, the voltage of the reference voltage source 22 in the second differential amplifier 15a is adjusted and the oscillation frequency of the voltage-controlled oscillator 18a is made to be the center frequency at the equilibrium condition of the second differential amplifier 15a.
The differential balance adjusting circuit 14 is adjusted so that when the FM signal is not supplied to the input terminals 10 and 11, the voltage-controlled oscillator 18a oscillates at the center frequency of the second IF signal. This is a free running frequency adjustment of the phase locked loop type FM signal demodulator.
According to the first exemplary embodiment, the FM signal demodulator can be easily adjusted by adjusting the voltage of the reference voltage source 22 without adjusting the air-core coils 45 and 46 of the voltage-controlled oscillator 18. Further, the working point of the differential amplifier can be kept on the center of the dynamic range and the dynamic range can be wide even in a low voltage circuit.
Second exemplary embodiment
FIG. 5(a) is a block diagram of part of a phase locked loop type FM signal demodulator in accordance with a second exemplary embodiment of the present invention. The blocks having similar functions to those in FIG. 3(a) of the first exemplary embodiment are numbered with the same reference numbers and, thus, their explanations are omitted.
A voltage source is supplied from a constant voltage source 72 to a second differential amplifier 15b which is different from the first exemplary embodiment. Two input terminals of a voltage comparator 20a are connected to demodulator output terminals 16 and 17 of the second differential amplifier 15b so that an output proportional to the difference between the outputs at the demodulator output terminals 16 and 17 is obtained at an output terminal 21a of voltage comparator 20a.
In voltage-controlled oscillator 18b shown in FIG. 5(b), the circuit elements having similar functions to those in FIG. 3(b) are numbered with the same reference numbers and, thus, their explanations are omitted. The ground side terminal of an air-core coil 45 is grounded by a parallel connection of capacitor 70 and a variable reference DC voltage. The capacitor 70 is provided to create a sufficiently low impedance at 400 MHz (second IF frequency of the satellite broadcast receiver). The oscillating frequency is adjusted by finely adjusting the cross terminal voltages of the variable capacitance diodes by the variable reference voltage 17.
The differential amplifier 15a is the same circuit as shown in FIG. 4(a) except that the differential amplifier 15a is connected to a fixed DC voltage source 72 instead of a variable DC voltage 22.
A constant voltage source 72 is supplied to second differential amplifier 15b. Two input terminals of a voltage comparator 20a are connected to demodulator output terminals 16 and 17 of second differential amplifier 15b so that an output which is proportional to the difference between the outputs at demodulator output terminals 16 and 17 is obtained at output terminal 21a of voltage comparator 20a.
FIG. 6 shows an input-output voltage characteristic of the second differential amplifier 15a used in the phase locked loop type FM signal demodulator shown in FIG. 5(a) in accordance with the second exemplary embodiment of the present invention.
In FIG. 5(a), when the center frequency of the second IF signal is provided from terminals 10 and 11 to the phase locked type FM signal demodulator, the voltage-controlled oscillator 18b is phase-locked and oscillates at the center frequency of the second IF signal. However, because the variable capacitance diodes 40 and 41 usually have a capacitance dispersion of ±15% at a constant cross terminal voltage, as described above, the oscillating frequency characteristic against the cross terminal voltage is not constant. That is, the output voltage of the differential amplifier 15a varies and, as a result, equilibrium is not always maintained.
As shown in FIG. 6, the voltage-controlled oscillator 18b oscillates at a center frequency of the second IF signal at the standard control voltage, when the variable capacitance diodes 40 and 41 have a standard capacitance value. Accordingly, the working point becomes point A.
However, when both of the variable capacitance diodes 40 and 41 have capacitance values larger than the standard value, it is necessary to supply a higher voltage than the standard value to the control terminal 44 so voltage-controlled oscillator 18b oscillates at the center frequency of the second IF signal. Accordingly, the second differential amplifier 15a moves from equilibrium and the working point becomes point B. At this time, a voltage corresponding to the output difference between terminals 62 and 63 corresponding to demodulator output terminals 16 and 17, is provided at the output terminal 21a of the voltage comparator 20a.
If the reference voltage 71 of the voltage-controlled oscillator 18b is decreased lower than the standard value, that is if the cathode potential of the variable capacitance diode 41 is adjusted to be relatively higher, the working point returns to point A and the second differential amplifier 15b moves to equilibrium. In an adjustment, the voltages of terminals 62 and 63 are provided to the voltage comparator 20a and the voltage of the reference voltage source 71 is adjusted so that the voltage difference between working points B and E is minimized. The voltage comparison provided by output terminal 21a of voltage comparator 20a is obtained at this time and can be used as a control voltage for an automatic frequency control circuit. In the second exemplary embodiment, it is possible to provide a dead zone as in the first exemplary embodiment. The differential balance adjusting circuit 14 is also adjusted as in the first exemplary embodiment.
Thus, in the second exemplary embodiment, the FM signal demodulator can be easily adjusted by adjusting the voltage of the reference voltage source 71 without adjusting air-core coils 45 and 46 of voltage-controlled oscillator 18.
Further, the working point of the differential amplifier can be maintained at the center of the dynamic range and the dynamic range can be widened in a low voltage circuit.
Third exemplary embodiment
FIG. 7(a) is a block diagram of an essential part of a phase locked loop type FM signal demodulator in accordance with a third exemplary embodiment of the present invention. The blocks having similar functions to those in FIG. 3(a) and FIG. 5(a) of the first and second exemplary embodiments, respectively, are numbered with the same reference numbers and the blocks having similar functions to those in FIG. 1(a) of the prior art such as second IF signal input terminal 1, SAW bandpass filter 2 and second IF amplifier 3 are numbered with the same reference numbers and, thus, their explanations are omitted.
FIG. 7(b) is a circuit diagram of a voltage-controlled oscillator 18c. In FIG. 7(b), the circuit elements having similar functions to those in FIG. 3(a) are numbered with the same reference numbers and, thus, their explanations are omitted. The third exemplary embodiment includes micro strip lines 75 and 76 in place of air-core coils 45 and 46 and chip coil inductor 73 in place of air-core coil 43. Microstrip Lines and Slotlines, Artech House, inc., by K. C. Grupts, Ramesh Garq and I. J. Bahi, incorporated herein by reference, discusses microstrip lines.
A resonant circuit composed of the variable capacitance diodes 40 and 41 and the micro strip lines 75 and 76 oscillates at its intrinsic resonant frequency. The voltage controlled oscillator 18c oscillates maintaining differential balance if the capacitances of the variable capacitance diodes 40 and 41 and length of the micro strip lines 75 and 76 are substantially the same. The voltages at the cathodes of the variable capacitance diodes 40 and 41 have reverse phases and nearly equal amplitudes because the oscillation circuit is symmetric.
Further, because the junction point between the variable capacitance diodes 40 and 41 forms an imaginary ground point for the differential amplifier 18c including transistors 33 and 34, the stability of the oscillation state is barely affected when a video signal is applied at this point from the outside and the differential amplifier 18c is modulated.
As in the first and the second exemplary embodiments, it is desirable that the output impedance of the differential amplifier 15 seen from the control terminal 44 is as low as possible at video frequency bands lower than 10 MHz. It is also desirable that the impedance of the control terminal 44 seen from the junction point of the variable capacitance diodes 40 and 41 is high enough at the second IF signal of 400 MHz.
In the third exemplary embodiment, a chip coil inductor 73 is used instead of an air-core coil 43. The inductance of the chip coil inductor is approximately 120 nH. A chip coil inductor can replace air-core coil 43 in the first and the second exemplary embodiments and an air-core coil can be used instead of a chip coil inductor in the third exemplary embodiment and vice versa.
In a printed micro strip line, electromagnetic field concentrates between the ground pattern on the back side of the printed circuit board and the micro strip line on the face side of the printed circuit board. Therefore, most of the oscillation power of the voltage-controlled oscillator 18c exists inside the dielectric of the printed circuit board and beneath the micro strip lines. As a result, radiation in the air is reduced and is less then the radiation from the air-core coils. In addition, if spiral lines are used instead of strip lines, the concentration of the electromagnetic field increases.
FIG. 8 illustrates the frequency characteristic measured from input terminal 1 to monitor terminal 7 of a second IF signal in a phase locked loop type FM signal demodulator in accordance with the third exemplary embodiment of the present invention. The characteristic A was measured when the voltage-controlled oscillator 18c does not oscillate and characteristic B was measured when the voltage-controlled oscillator 18c normally oscillates and the phase locked loop is locked.
Although some interference was detected (1) causing the signal of the voltage-controlled oscillator 18c to radiates, (2) causing leaks into the input stage of the FM signal demodulator, (3) disturbing the wave form of the SAW bandpass filter a small amount, the amount of interference is improved as compared to the interference generated by the prior art.
The video signal demodulated using the FM signal demodulator in accordance with the exemplary embodiment of the present invention was measured to have good characteristics with a differential gain of less than 1% and a differential phase of less than one degree when using satellite broadcast transmission standards. The modulation sensitivity which is the variation of the oscillating frequency against the control voltage of voltage-controlled oscillator 18c was measured to be approximately 20 MHz/V and the signal to noise ratio of the video signal was measured to be less than 65 dB.
In the three exemplary embodiments described above, two variable capacitance diodes are used improving the differential function of the voltage-controlled oscillator. One of the two variable capacitance diodes can be replaced with a chip capacitor having approximately the same capacitance. The exemplary embodiments of the present invention can accommodate an oscillating frequency of 400 MHz and a working frequency band width of 27 MHz for one channel while maintaining linearity between the oscillating frequency and the control voltage at the working frequency band. The higher the modulation sensitivity, the smaller the amplitude of the control voltage. As a result, good linearity of the differential amplifier and the voltage controlled oscillator can be obtained since a smaller output is possible.
Good linearity of the control voltage can be maintained if the dynamic range of the differential amplifier is narrow. If the modulation sensitivity is larger than 40 MHz, the signal to noise ratio of the demodulator can become worse. Therefore, in this case, it can be preferable to use one variable capacitance diode.
Good linearity between the oscillating frequency and the control voltage can be obtained by carefully selecting the capacitance-voltage characteristic of the variable capacitance diode. For example, sometimes usage of fixed capacitor having an adequate capacitance value instead of or with the variable capacitance diode to correct the capacitance-voltage characteristic of the variable capacitance diode is effective for obtaining good linearity between the oscillating frequency and the control voltage if the capacitance-voltage characteristic of the variable capacitance diode degrades the linearity. Of course, the inductance of the coil is selected to an adequate value corresponding to the capacitance value.
Thus, according to the exemplary embodiments, an FM signal demodulator can be realized which (1) prevents interference due to radiating and leaking of the oscillation power of the voltage-controlled oscillator to the input stage of the FM signal demodulator and (2) has a stable demodulation characteristic.
Voltage-controlled oscillator 18a used in the first exemplary embodiment can be replaced by voltage-controlled oscillator 18b used in the second exemplary embodiment and voltage-controlled oscillator 18b used in the second exemplary embodiment can be replaced with voltage-controlled oscillator 18a used in the first exemplary embodiment. The chip capacitor having fixed capacitance can be replaced with either variable capacitance diode 40 or 41.
It is obvious that any combination of a demodulator circuit and a voltage-controlled oscillator can be used.
The above-mentioned exemplary embodiments are not restricted to use for satellite broadcast reception and are generally applicable to demodulators for an FM signal.
The invention may be embodied in other specific form without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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A frequency modulation signal demodulator receives an intermediate frequency signal to demodulate a FM signal. The frequency modulation signal demodulator includes a voltage-controlled oscillator having variable capacitance diodes. The voltage-controlled oscillator varies the oscillating frequency of a signal by controlling a voltage across the variable capacitance diodes using a DC voltage. Also included is a phase comparator which produces a phase difference by comparing the phase of the intermediate frequency signal to the phase of the signal from the voltage-controlled oscillator and provides a direct current voltage signal corresponding to the phase difference. Also included is a differential amplifier which has an adjustable reference voltage source. The differential amplifier amplifies the direct current voltage signal to produce a demodulated signal. The demodulated signal is negatively fed back to the voltage-controlled oscillator as the direct current signal.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of application Ser. No. 10/202,430, filed Jul. 23, 2002, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to plumbing devices used to clear drains and, more specifically, to a plumbing device that uses a compressed gas to provide a sudden burst of energy to forcibly act against an obstruction that may interfere with the proper function of a drain.
[0004] 2. Description of the Related Art
[0005] Clogged drains are a problem that affects millions of households and businesses each year. It is a situation that often occurs due to obstructions along the flow path of the drain by items such as paper, soap residue, hair, lotion, and stringy, fibrous waste. While there are a number of plumbing devices that offer the promise of unstopping or unclogging drains, none offer the ability to clear a clogged pipe with the efficiency, ease, affordability, and force of the present invention.
[0006] When a drain becomes clogged, there are a number of known approaches for clearing the obstruction. One of the most common methods of treating clogged drains is to use a commercial drain cleaner. However, often these drain cleaners are some of the most dangerous chemicals found in a home or business. For instance, these products commonly use lye or acid, which can harm health, the wastewater stream, and pipes.
[0007] While there are alternatives to commercial drain cleaners, the effectiveness of these alternatives generally requires an appreciable amount of manual force or the sacrifice of flexibility and mobility. For instance, some devices use a simple force cup plunger, or a bellows-style plunger, to open a clogged sink drain by repeatedly pumping the plunger up and down directly over the clogged drain. While these plungers avoid the caustic chemicals associated with drain cleaners, they are generally less effective and require a significant amount of manual labor. As one may appreciate, the need to pump the plunger in a repetitive manner may cause a person to become quite exhausted and, indeed, may be beyond the ability of some individuals. In addition, depending on the size or number of obstructions, the use of manual labor may not be sufficient to dislodge the obstruction from the drain.
[0008] There are some plungers that contemplate the use of a compressed gas to forcibly remove obstructions clogging a drain. These compressed gas plungers, however, are relatively expensive and may be unaffordable to many individuals or households. In addition, while such plungers may not require the same amount of manual labor as a simple force cup plunger or a bellows-style plunger, existing compressed gas plungers generally do not harness and effectively release all of the available energy provided by the pressurized gas.
[0009] It has been proposed that using a sudden burst of gas pressure is a preferable way to clear a clogged drain. However, plumbing devices that employ this method are often bulky and generally take a form different from a traditional plunger, which can make such devices difficult to use and inconvenient to store. In addition, the size and shape of these devices limits the flexibility of their use in a number of different but common plumbing scenarios, such as a clogged toilet, stopped tub, and a clogged sink drain, particularly in tight quarters or where space is limited. Furthermore, some of these devices use a scored sheet metal diaphragm, or a metal disk having a non-uniform thickness, for storing a predetermined quantity of gas and releasing the gas automatically at a predetermined pressure. These metal disks generally require additional manufacturing steps which result in higher costs.
[0010] Accordingly, there is a need for a plumbing device that rapidly and effectively clears obstructed drains, that is environmentally friendly, and does not require the use of harsh chemicals. In addition, there is a need for a plumbing device that is easy to use, does not require a significant amount of manual labor, and is relatively inexpensive to manufacture. Furthermore, there is a need for a plumbing device in the form of a plunger that harnesses the energy of a compressed gas and efficiently directs the gas's energy in a sudden burst to expel an obstruction in a clogged drain. The present invention satisfies these and other needs and provides further related advantages.
SUMMARY OF THE INVENTION
[0011] The present invention is embodied in an air-burst drain plunger that uses a compressed gas to provide a sudden burst of energy to forcibly act against an obstruction that may clog or otherwise interfere with the proper function of a drain.
[0012] In one embodiment, the air-burst drain plunger comprises a chamber for receiving a compressed gas, and a sealing member for providing a secure connection between the chamber and a drain opening. A burst disk constructed from a substantially non-metallic material is positioned to create a barrier between the chamber and sealing member. The burst disk has a substantially smooth surface and is adapted to burst when the pressure in the chamber reaches a predetermined level. The thickness of the burst disk may be calibrated to immediately burst when the pressure in the chamber reaches the predetermined level.
[0013] In another embodiment, the plunger comprises a burst disk of substantially uniform thickness and a chamber having an upper and lower end. The burst disk is positioned between the upper and lower end for creating a barrier within the chamber. While the lower end of the chamber is connected to a sealing member for securing the plunger to an opening in the drain, the upper end of the chamber is connected to a handle. The handle has at least one trigger for allowing a pressurized gas to enter into the inner cavity.
[0014] In another embodiment, the plunger comprises a chamber, a handle, and a burst disk. The chamber is designed to receive a compressed gas and has an upper end and a lower end. The lower end is connected to a sealing mechanism for securing the plunger to an opening in the drain. The handle is connected to the upper end of the chamber and has an area adapted to receive a pressurized gas cartridge having a puncture point. The handle has a trigger that, when activated, allows for the handle to travel toward the chamber, puncture the cartridge, and allow pressurized gas to enter the inner cavity. The burst disk separates the chamber from the sealing mechanism and creates a barrier. The burst disk is adapted to burst when the pressurized gas enters the chamber.
[0015] In another embodiment, the plunger comprises a chamber, a nozzle, and a burst disk. The chamber has an upper end and a lower end. The upper end of the chamber is designed to receive a nozzle having a piercing pin for puncturing a pressurized gas cartridge housed in a cover, which can be attached to the upper end of the chamber. The cover is designed in such a manner that when the cover is forced to move axially toward the chamber, the piercing pin punctures the gas cartridge allowing gas to escape therefrom and travel through an air inlet in the pin and into the nozzle. The nozzle has at least one passage that directs the gas into the upper chamber wherein the burst disk is adapted to rupture when the pressure of chamber's inner cavity reaches a predetermined level.
[0016] Other features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, which illustrate, by example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are intended to provide further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present invention and together with the description serve to explain the principles of the invention.
[0018] [0018]FIG. 1 is a perspective view of an air-burst drain plunger having a handle for gripping and positioning the plunger and a reversible sealing member for providing communication between the plunger and a drain.
[0019] [0019]FIG. 2 is an assembly view of the plunger of FIG. 1.
[0020] [0020]FIG. 3 is a cross-sectional elevation view of the plunger, taken substantially along section plane 3 - 3 of FIG. 1, showing a canister of compressed gas aligned with the longitudinal axis of the plunger, and an upper and lower chamber for receiving and channeling the force of the gas through the plunger.
[0021] [0021]FIG. 4A is a cross-sectional elevation view of the plunger, similar to FIG. 3, wherein the sealing member is reversed, the handle is depressed, and the canister is ruptured by a nozzle pin, wherein the compressed gas is shown escaping into the upper chamber of the plunger.
[0022] [0022]FIG. 4B is a further cross-sectional elevation view of the plunger, similar to FIG. 4A, wherein a burst disk separating the upper and lower chambers is ruptured and the force of the gas is released from the upper chamber and out through the lower chamber.
[0023] [0023]FIG. 5 is an elevation view of the nozzle.
[0024] [0024]FIG. 6 is a cross-sectional elevation view of the nozzle, taken substantially along section plane 6 - 6 of FIG. 5, showing the gas pathway through the nozzle and pin.
[0025] [0025]FIG. 7 is a top plan view of the nozzle, showing the top of the nozzle having at least two inlet holes for receiving the compressed gas from the canister.
[0026] [0026]FIG. 8 is a cross-sectional elevation view of an alternative embodiment of the nozzle, shown in FIG. 6, with the gas pathway through the nozzle.
[0027] [0027]FIG. 9 is a perspective view of an alternative embodiment comprising a one-handed grip for use with the plunger.
[0028] [0028]FIG. 10 is a cross-sectional elevation view of the one-handed grip taken substantially along section plane 10 - 10 of FIG. 9.
[0029] [0029]FIG. 11 is a cross-sectional elevation view similar to FIG. 10 showing the one-handed grip in operation.
[0030] [0030]FIG. 12 is a perspective view of another embodiment of the plunger with the one-handed grip and a flexible hose coupling the reversible sealing member to the plunger.
[0031] [0031]FIG. 13 is a perspective view of an alternative embodiment of the air-burst drain plunger having a lower chamber having a wider diameter.
[0032] [0032]FIG. 14 is an assembly view of the plunger of FIG. 13.
[0033] [0033]FIG. 15 is a cross sectional elevation view of the plunger, taken substantially along section plane 15 - 15 of FIG. 13, showing a canister of compressed gas aligned with the longitudinal axis of the plunger, and an upper and lower chamber for receiving and channeling the force of the gas through the plunger.
[0034] [0034]FIG. 16 is a top plan view of an alternative embodiment of the nozzle with two semi-circular inlet holes along the perimeter edge of the piercing pin casting.
[0035] [0035]FIG. 17 is an elevation view of the nozzle of FIG. 16.
[0036] [0036]FIG. 18 is a cross-sectional view of the nozzle of FIG. 17, taken substantially along section plane 18 - 18 of FIG. 17, showing the gas pathway through the nozzle and pin.
[0037] [0037]FIG. 19 is a cross-sectional elevation view of the plunger, similar to FIG. 15, wherein the handle is depressed and the canister is ruptured by a nozzle pin, wherein the compressed gas is shown escaping into the upper chamber of the plunger.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] As shown in the drawings, the present invention is embodied in an air-burst drain plunger, generally referred to by the reference numeral 10 , for clearing a drain or pipe. The plunger 10 is designed to harness the energy from a compressed gas and propel the gas to an obstruction point along a clogged drain, using the energy of the gas to forcibly remove the obstruction without the need for excessive manual labor. The following is a detailed description of the preferred embodiment, as shown in FIG. 1, having a handle 12 for gripping and positioning the plunger 10 , a reversible sealing member 14 for providing a connection between the plunger and a drain (not shown), and security triggers 16 for the safe operation of the plunger.
[0039] The handle 12 is preferably injection-molded and made from a polymer. However, as one skilled in the art can appreciate, the handle 12 may be composed of any suitable material such as a composite, metal or ceramic. While the sealing member 14 is preferably a flexible molded rubber cup, the sealing member may have any suitable shape and composition so long as a secure communication between the plunger 10 and the drain is achieved. The sealing member 14 preferably accommodates standard drain openings ranging from about 1 inch to about 4 inches in diameter, however, as one in the art can appreciate, the plunger 10 can accommodate sealing members of other sizes.
[0040] In addition to the handle 12 , sealing member 14 , and security triggers 16 , the preferred embodiment is further comprised of a compressed gas canister 18 , generally housed within a cover 20 which is connected to the handle 12 . The plunger 10 further comprises a hollow chamber 22 divided by a burst disk 24 into an upper chamber 26 and a lower chamber 28 , as shown in FIGS. 2 and 3.
[0041] The gas canister 18 is preferably a small 12 g disposable metal-case compressed air (CO 2 ) cartridge pressurized at about 500 to 900 psi. Similar cartridges are commercially available from hardware retailers throughout the United States, such as Wal-Mart Stores in Los Angeles, Calif., under the brand name Crossman. The canister 18 can be any suitable CO 2 cartridge, or other suitable type of gas cartridge, that is capable of fitting within the cover 20 , but is preferably a canister having a length that provides for an installed axial clearance of approximately a quarter of an inch ({fraction (1/4)}″) with the nozzle piercing pin (discussed below). In addition, as one skilled in the art can appreciate, while the use of a compressed gas canister 18 is contemplated for the preferred embodiment, the plunger 10 could be connected to any suitable source, other than a canister, for delivering a compressed gas into the chamber 22 . For example, the compressed gas could be delivered from a source external to the plunger 10 by a hose or other line.
[0042] Alternatively, the gas canister 18 may be a smaller 8 g disposable metal-case compressed air (CO 2 ) cartridge pressurized at about 900 psi. This cartridge has a smaller internal volume than the preferred embodiment, which helps to reduce the discharge pressure of the canister and reduce the risk of back splash when the plunger 10 is in operation. A smaller version of the cover 20 may be used when the smaller 8 g cartridge is installed in the plunger 10 , as shown in FIG. 15. The smaller version of cover 20 may be sized to provide for the same preferred axial clearance between the canister and the nozzle, as described in the previous paragraph, when the 8 g cartridge is installed. This smaller cover 20 also helps to control costs and improves the efficiency of manufacturing the plunger 10 .
[0043] The cover 20 is preferably injection-molded and made from a polymer capable of securing the canister 18 to the plunger 10 and preventing the canister from exploding away when the plunger is in operation. However, one skilled in the art can appreciate that the cover 20 may be composed of any suitable material such as a composite, metal, or ceramic. A good connection between the cover 20 and handle 12 is important to provide a stable encasing for the canister 18 and limit air leakage during operation of the plunger 10 . While any suitable fastener may be used to connect the cover 20 to the handle 12 , such as brackets or clips, the cover is preferably attached to the handle by a threaded connection.
[0044] The lower chamber 28 is preferably a cylindrical body that may be joined to either end of the sealing member 14 by a threaded connection or interference fit. The upper chamber 26 , which also is preferably a cylindrical body, is designed to connect with the handle 12 such that the handle can move axially a limited distance relative to the chamber. The two chambers 26 , 28 are preferably attached to each other by a threaded connection along a flange 30 . The flange 30 provides for access to and replacement of the burst disk 24 . The chambers 26 , 28 are preferably injection-molded and made from a polymer, however, one skilled in the art can appreciate that the chambers may be composed of any suitable material such as metal or ceramic. In addition, the chambers 26 , 28 preferably have raised axial ribs 32 to improve grip during manual assembly and disassembly of the two chambers.
[0045] The size of the upper chamber 26 is designed to accumulate a sufficient volume of compressed gas, before the burst disk 24 ruptures, to provide sufficient force to dislodge most drain obstructions. The size of the lower chamber 28 is designed to deliver the compressed gas to the drain opening, once the burst disk 24 ruptures, without unnecessary dissipation of the energy. In the preferred embodiment, the upper chamber 26 has a volume of about 3.3 cubic inches. The lower chamber 28 in the preferred embodiment has a volume of about 2.5 cubic inches.
[0046] In an alternative embodiment, the lower chamber 28 has a larger volume than that of the upper chamber as represented in FIG. 15. The lower chamber 28 of FIG. 15 has a volume of about 18.1 cubic inches, a length of approximately 9.0 inches, and an exterior diameter of approximately 1.9 inches. The larger internal volume of this alternative embodiment of chamber 28 helps to reduce the discharge pressure from the upper chamber 26 before the energy of the compressed gas is propelled out from the sealing member 14 . In addition, the alternative embodiment of chamber 28 helps to significantly reduce the potential of back splash of standing water during operation of the plunger.
[0047] When the handle 12 is depressed toward the chamber 22 , as shown in FIGS. 4A and 4B, a nozzle 34 connected to the upper end of the upper chamber 26 is adapted to pierce through the canister 18 so as to permit the rapid discharge of the compressed gas from the canister into the upper chamber. Preferably, a compression spring 36 is nestled between the handle 12 and the upper chamber 26 to normally bias the handle away from the upper chamber and, thus, provide a space or clearance between the lower end of the canister 18 and the upper end of the nozzle 34 . In this way, the spring 36 helps prevent the unintended rupture of the canister 18 .
[0048] As shown in FIGS. 2 and 3, optional security triggers 16 may be provided along the connection between the handle 12 and the upper chamber 26 . These security triggers 16 help to provide further protection against the unintended rupture of the canister 18 . The security triggers 16 are designed to restrict axial movement of the handle 12 by positive stops 38 obstructing the downward travel path of the handle. The position of the positive stops 38 , as shown in FIG. 3, is maintained by the urging of compression springs 40 on the security triggers 16 . The travel path of the handle 12 may be freed by manually compressing the security triggers 16 toward the handle so that the positive stops 38 pivot or rotate away from the travel path, as shown in FIGS. 4A and 4B. The security triggers 16 may be secured to the handle using snap-fit protrusions.
[0049] The security triggers 16 are also designed and configured on the preferred embodiment to require the use of two hands when operating the plunger 10 , which forces the operator to position both hands on the handle away from the wastewater or drain. The application of a downward force with both hands, which is necessary to cause the release of the compressed gas from the canister 18 , also helps assure a good surrounding seal between the sealing member 14 and the drain opening. Assuring a good seal reduces the risk of back splash of standing water during operation of the plunger 10 .
[0050] [0050]FIGS. 15 and 19 illustrate an embodiment of the plunger 10 without security triggers. This embodiment of the plunger 10 could employ a smaller handle 102 with a wingspan that is approximately 8 inches, which is shorter than the handle 12 by approximately 1.5 inches. This embodiment of the plunger 10 could also be molded such that the security triggers 16 could be manually installed onto and removed off of the handle. The plunger 10 without security triggers improves the ease by which the plunger may be used. For example, a handle without the security triggers could enable a person to operate the plunger with a single hand. In addition, the plunger may be operated with lower risk that the triggering mechanism will become stuck or broken. The advantages of having a handle without triggers also extend to lowering the manufacturing cost of the plunger and the efficiency by which the plunger can be manufactured.
[0051] One embodiment of nozzle 34 is shown in greater detail in FIGS. 5 - 7 . The nozzle 44 has a piercing pin 42 preferably positioned near the center of the nozzle. The nozzle 44 is preferably composed of brass or zinc die cast and may be attached to the upper chamber 26 by a threaded connection. Alternatively, the nozzle 44 could be attached by interference fit. The pin 42 is preferably composed of hardened stainless steel and is staked into the nozzle 44 , but could be attached by threaded connection or other appropriate means. Gas inlet holes 46 are provided in the pin 42 and in the nozzle 44 around the pin, as shown in FIG. 7, for receiving and directing the compressed gas into passages 52 within the nozzle 44 , as shown in FIG. 6. The gas is transferred through the passages 52 from the pin end of the nozzle to the opposite end of the nozzle, which communicates with the upper chamber, as shown in FIG. 4A.
[0052] An alternative embodiment of the nozzle 34 is shown in greater detail in FIGS. 16 - 18 . The nozzle 34 has a piercing pin 90 preferably positioned near the center of the nozzle. The nozzle 34 is preferably composed of brass or zinc die cast and may be attached to the upper chamber 26 by a threaded connection. Alternatively, the nozzle 34 could be attached by an interference fit. The pin 90 is preferably composed of hardened stainless steel and has a diameter of approximately 0.100 inches. The pin 90 is nestled or integral with a pin base 92 , which has a diameter of approximately 0.250 inches. The nozzle 44 preferably has a central passage 94 having a diameter of approximately 0.252 inches for receiving the pin base 92 . The pin base 92 is staked into the nozzle 44 , but could be attached by a threaded connection or other appropriate means.
[0053] A gas inlet channel 96 is provided in and runs the length of the pin 90 and base 92 , as shown in FIG. 18, for receiving and directing the compressed gas into the passage 94 within the nozzle 44 . The gas is transferred from the pin 90 to the passage 94 where the gas moves through an opening at the bottom end of the nozzle, which communicates with the upper chamber, as shown in FIG. 19.
[0054] The passage 94 preferably has channels 98 along its sides, as shown in FIG. 18. These channels 98 provide additional gas inlet holes 100 , as shown in FIG. 16 for receiving and directing the compressed gas into the passage 94 . Although the channels 98 preferably extend the full length of the passage 94 , the channels may extend to a length which is equal to or slightly longer (e.g. 0.44 inches) than the pin base 92 . The pin base 92 may alternatively have groves (not shown) along the length of the pin base that correspond to the channels 98 . These groves act to further assist the receiving and directing of compressed air from the compressed gas cartridge to the upper chamber 26 .
[0055] One skilled in the art can appreciate that any suitable device for puncturing the canister 18 and channeling the gas into the upper chamber 26 may be substituted for the nozzle 34 . For instance, the pin 42 could be substituted for a pin 54 without an inlet hole or a passage as depicted in FIG. 8. In addition, multiple pins could be substituted for the single pin or, alternatively, the passages 52 could be formed in the pin 42 itself, as opposed to around the pin. Furthermore, while the preferred embodiment utilizes a nozzle 34 , one skilled in the art can appreciate that the disclosed nozzle is not necessary where a device, other than a canister 18 , is used for delivering a compressed gas to the plunger 10 . For instance, a pump for delivering a compressed gas could be substituted for the canister 18 , which would not require the use of the nozzle 34 .
[0056] The plunger 10 is operated by gripping the handle 12 with both hands and positioning the plunger at the opening of a drain so as to create a secure connection between the sealing member 14 and the drain. Depending on the situation, the sealing member 14 may be oriented in the position shown in FIG. 3 or FIG. 4A. Once the plunger 10 is properly positioned, the security triggers 16 may then be compressed to rotate the positive stops 38 away from the travel path and to allow the handle 12 to be moved toward the chamber 22 for piercing the canister 18 by the nozzle 34 , as shown in FIG. 4A. Piercing the canister 18 will cause the compressed gas to rush into the inlet holes 46 and through the passages of the nozzle 34 and pin 42 , and into the upper chamber 26 wherein the energy of the gas may be harnessed and stored momentarily by the burst disk 24 . After a sufficient amount of energy is harnessed, the burst disk 24 will rupture, propelling the energy of the gas through the lower chamber 28 , as shown in FIG. 4B, out from the sealing member 14 , and into the clogged drain to forcibly act against an obstruction.
[0057] The capacity of the burst disk 24 to harness energy in the upper chamber 26 is primarily a function of the thickness and material composition of the disk. While the burst disk 24 is preferably a disposable thin flat polymer having a substantially uniform thickness, which is calibrated to burst substantially instantaneously when the pierced canister releases pressurized gas into the upper chamber 26 , the burst disk 24 may be composed of other suitable materials, such as composites or metals. Although the thickness of the burst disk 24 in this embodiment is preferably between about 0.007 to 0.021 inches, a burst disk with a thickness greater than this range will not adversely affect the ability of the plunger 10 to effectively remove obstructions from a clogged drain. In addition, placing multiple burst disks between the upper and lower chambers 26 , 28 , simulating the effect of a thicker burst disk, will generally increase the amount of harnessed energy directed to clear the obstruction from the clogged drain. In one embodiment, each disk 24 has a thickness of approximately 0.007 inches, a tensile strength of approximately 4500 psi, and a diameter of approximately 1.28 inches.
[0058] The preferred embodiment utilizes a plastic burst disk 24 that has a relatively smooth, planar surface with a substantially uniform thickness. There are advantages of using a burst disk 24 having this structure and composition. For example, a metallic disk having an uneven thickness, or a surface with scoring or other intentional surface discontinuity, may lead to a premature rupture event, which will cause a loss in the capacity for the burst disk to harness sufficient energy to clear a clogged drain. In contrast, a burst disk that is not scored and has a relatively even surface with a substantially uniform thickness is more readily available and is easier and less costly to manufacture. Moreover, the burst disk 24 of the preferred embodiment will rupture completely and substantially instantaneously when the pressure in the upper chamber 26 reaches a predetermined level. This causes the pressurized gas in the lower chamber 28 to exit in a huge “burst” that is sudden and powerful. As a result, the force acting against the obstruction in the drain is maximized.
[0059] A ruptured burst disk 24 may be replaced by detaching the upper chamber 26 from the lower chamber 28 and removing the ruptured disk from the lower chamber. After the ruptured disk 24 is removed, a new disk or disks may be placed above a washer 48 , which is secured to the lower chamber 28 . The washer 48 is preferably made from a soft die-cut polymer, which provides support for the burst disk 24 and a good sealing connection between the lower and upper chambers 26 , 28 when they are attached together. While the washer 48 may be adhered to the lower chamber 28 , it could alternatively have a press fit diameter. After the new burst disk 24 or disks are properly positioned, the lower and upper chambers 26 , 28 may be re-connected. The two chambers 26 , 28 may be attached together by a threaded connection or interference fit. However, as one in the art may appreciate, any suitable means may be used for attaching the two chambers 26 , 28 , such as fastening hooks or grapplers, so long as the connection between the two chambers is secure enough to maintain the connection and prevent escaping gases.
[0060] A webbed or screened discharge outlet 50 may be provided between the sealing member 14 and lower chamber 28 to prevent the propelling of solid debris from the chamber 22 . Because it is possible for an operator to load the upper chamber 26 with projectiles such as rocks, bullets or pellets, and then use the force of the compressed gas to catapult the elements toward another person or object, the webbed discharge outlet 50 also serves as a safety measure to help avoid both accidents and intentional tortious acts. However, as one skilled in the art can appreciate, the webbed discharge outlet 50 is not necessary for the proper operation of the plunger 10 for clearing drains.
[0061] In another embodiment, the air burst drain plunger may be operated by a one-handed grip 60 as shown in FIGS. 9 - 12 , to provide the flexibility of operating the plunger 10 with one hand and in areas of restricted access where a two handed operation is difficult or impossible. The one-handed grip 60 , as shown in FIG. 9, comprises an adapter 62 and an assembly 64 .
[0062] The assembly 64 comprises a receptacle 66 , lever 68 , and drive pin 70 . The receptacle 66 has an inner cavity 72 with an opening on one end adapted for receiving the drive pin 70 and is threaded on the other end for receiving the adapter 62 . The lever 68 is connected to the receptacle 66 and adapted to rotate so as to force the drive pin 70 through the opening and into the inner cavity 72 .
[0063] The adapter 62 is designed to be disposed between the upper chamber 26 and assembly 64 and to connect the plunger with the assembly by means of a threaded connection. As one skilled in the art can appreciate, however, the one-handed grip 60 could be connected to the plunger 10 by an interference fit, brackets, latches, or other suitable means. The adapter 62 is comprised of a casing 74 , nozzle 34 , spring 76 , and sleeve 78 . The nozzle 34 is the same nozzle described above and as shown in FIGS. 5 - 8 . The casing 74 is hollow with a small opening 80 in the middle for receiving the nozzle 34 and is preferably connected to the casing by a threaded connection, but could be connected to the casing by interference fit. Before the nozzle 34 is connected to the casing 74 , the spring 76 is placed in the upper hollow of the casing and the sleeve 78 is placed on one end of the spring away from the center of the casing. The nozzle 34 is then secured to the casing 74 which holds the spring 76 and sleeve 78 in alignment for receiving the canister 18 . The spring 76 is biased to force the sleeve 78 away from the center for the casing 74 .
[0064] With reference to FIGS. 10 and 11, the one-handed grip plunger 82 is operated by rotating or squeezing the lever 68 toward the receptacle 66 . As the lever 68 is drawn into contact with a side of the receptacle 66 , the drive pin 70 is forced into the inner cavity 72 pushing the canister 18 against the sleeve 78 and into the pin 42 on the nozzle 34 . When the canister 18 is pushed into the pin 42 , the pin will pierce the canister sending gas into the upper chamber 26 of the plunger 82 causing the burst disk 24 to rupture, which will send a sudden burst of energy through the lower chamber 28 and out the sealing member 14 . The canister is replaced by unfastening the assembly 64 from the adapter 62 , removing the pierced canister, placing a new canister on the end of the sleeve 78 , and refastening the assembly to the adapter.
[0065] In an alternative embodiment, a flexible hose 84 may be interposed between the sealing member 14 and the lower chamber 28 as shown in FIG. 12 for providing a user with the added flexibility of orienting the sealing member 14 in a number of directions or positions for creating a secure connection between the plunger 82 and the drain. The flexible hose 84 is preferably about ½ inch in diameter, about eighteen inches long, and is threaded or has threaded couplings 86 on each end. The hose 84 may be attached to the lower chamber 28 by interference fit, however, the hose preferably will be threaded to the chamber. The hose is preferably attached to the sealing member 14 through the use of a PVC pipe 88 . The pipe 88 is provided for a user to direct the positioning of the sealing member 14 and to hold the sealing member in place during operation of the plunger 82 . The pipe 88 is preferably about five inches long and is fastened to the hose by a threaded connection. The sealing member 14 is attached to the pipe 88 by interference fit or a threaded connection. While the pipe 88 is helpful in guiding the position of the sealing member 14 , one skilled in the art can appreciate that the pipe is not necessary for the operation of the plunger 82 .
[0066] Although the foregoing invention has been described in terms of certain preferred embodiments, other embodiments will become apparent to those of ordinary skill in the art, in view of the disclosure herein. Accordingly, the present invention is not intended to be limited by the recitation of preferred embodiments, but is instead to be defined solely by reference to the appended claims.
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An affordable plumbing device that uses a compressed gas and a burst disk having a relatively even surface of substantially uniform thickness to produce a sudden discharge of energy to forcibly act against any obstruction that may interfere with the proper function of a drain. The plumbing device has a cylindrical chamber for receiving the compressed gas and may generally take the shape of a plunger, which is flexible to use and is easy to store. A portion of the chamber forms a receiving chamber with the burst disk for harnessing and directing the energy of the compressed gas to clear the drain.
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